* Re: i2c: designware: Allow reduce bus speed by "clock-frequency" property
From: Wolfram Sang @ 2016-11-18 1:08 UTC (permalink / raw)
To: Jarkko Nikula; +Cc: linux-i2c, Wolfram Sang, Mika Westerberg, Andy Shevchenko
In-Reply-To: <20161110113720.16464-1-jarkko.nikula@linux.intel.com>
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On Thu, Nov 10, 2016 at 01:37:20PM +0200, Jarkko Nikula wrote:
> Allow more flexibility to bus speed selection. Now if there are I2C
> slave connections defined in ACPI the speed of slowest device on the bus
> will define the bus speed. However if also "clock-frequency" device
> property is defined we should use the slowest of these two.
>
> This is targeted to maker boards where developer may want to connect
> slower I2C slave devices to the bus than defined in existing ACPI I2C
> slave connections.
>
> Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Applied to for-next, thanks!
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* Re: [v4] i2c: designware: Implement support for SMBus block read and write
From: Wolfram Sang @ 2016-11-18 1:07 UTC (permalink / raw)
To: tnhuynh
Cc: Jarkko Nikula, Andy Shevchenko, Mika Westerberg, Wolfram Sang,
linux-i2c, linux-kernel, Loc Ho, Thang Nguyen, Phong Vo, patches
In-Reply-To: <1478746593-10905-1-git-send-email-tnhuynh@apm.com>
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On Thu, Nov 10, 2016 at 09:56:33AM +0700, tnhuynh@apm.com wrote:
> From: Tin Huynh <tnhuynh@apm.com>
>
> Free and Open IPMI use SMBUS BLOCK Read/Write to support SSIF protocol.
> However, I2C Designware Core Driver doesn't handle the case at the moment.
> The below patch supports this feature.
>
> Signed-off-by: Tin Huynh <tnhuynh@apm.com>
> Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Applied to for-next, thanks!
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* Re: [2/2] i2c: constify i2c_adapter_quirks structures
From: Wolfram Sang @ 2016-11-18 1:00 UTC (permalink / raw)
To: Julia Lawall; +Cc: Wolfram Sang, kernel-janitors, linux-i2c, linux-kernel
In-Reply-To: <1476552722-12352-3-git-send-email-Julia.Lawall@lip6.fr>
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On Sat, Oct 15, 2016 at 07:32:02PM +0200, Julia Lawall wrote:
> Check for i2c_adapter_quirks structures that are only stored in the
> quirks field of an i2c_adapter structure. This field is declared
> const, so i2c_adapter_quirks structures that have this property can be
> declared as const also.
>
> The semantic patch that makes this change is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @r disable optional_qualifier@
> identifier i;
> position p;
> @@
> static struct i2c_adapter_quirks i@p = { ... };
>
> @ok@
> identifier r.i;
> struct i2c_adapter e;
> position p;
> @@
> e.quirks = &i@p;
>
> @bad@
> position p != {r.p,ok.p};
> identifier r.i;
> struct i2c_adapter_quirks e;
> @@
> e@i@p
>
> @depends on !bad disable optional_qualifier@
> identifier r.i;
> @@
> static
> +const
> struct i2c_adapter_quirks i = { ... };
> // </smpl>
>
> The effect on the layout of the .o files is shown by the following
> output of the size command, first before then after the
> transformation:
>
> text data bss dec hex filename
> 3651 472 8 4131 1023 drivers/i2c/busses/i2c-axxia.o
> 3683 440 8 4131 1023 drivers/i2c/busses/i2c-axxia.o
>
> text data bss dec hex filename
> 1069 216 0 1285 505 drivers/i2c/busses/i2c-dln2.o
> 1101 192 0 1293 50d drivers/i2c/busses/i2c-dln2.o
>
> text data bss dec hex filename
> 3211 484 1 3696 e70 drivers/i2c/busses/i2c-viperboard.o
> 3243 460 1 3704 e78 drivers/i2c/busses/i2c-viperboard.o
>
> Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Squashed with the other similar patch and applied to for-next, thanks!
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* Re: [-next] i2c: digicolor: use clk_disable_unprepare instead of clk_unprepare
From: Wolfram Sang @ 2016-11-18 0:48 UTC (permalink / raw)
To: Wei Yongjun
Cc: Wolfram Sang, Baruch Siach, Wei Yongjun, linux-i2c,
linux-arm-kernel
In-Reply-To: <1477758677-7831-1-git-send-email-weiyj.lk@gmail.com>
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On Sat, Oct 29, 2016 at 04:31:17PM +0000, Wei Yongjun wrote:
> From: Wei Yongjun <weiyongjun1@huawei.com>
>
> since clk_prepare_enable() is used to get i2c->clk, we should
> use clk_disable_unprepare() to release it for the error path.
>
> Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
> Acked-by: Baruch Siach <baruch@tkos.co.il>
Applied to for-current, thanks!
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* Re: i2c: make busses/i2c-pxa-pci.c explicitly non-modular
From: Wolfram Sang @ 2016-11-18 0:45 UTC (permalink / raw)
To: Paul Gortmaker
Cc: linux-kernel, Wolfram Sang, Sebastian Andrzej Siewior, linux-i2c
In-Reply-To: <20161031175947.10531-1-paul.gortmaker@windriver.com>
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On Mon, Oct 31, 2016 at 01:59:47PM -0400, Paul Gortmaker wrote:
> The Kconfig currently controlling compilation of this code is:
>
> drivers/i2c/busses/Kconfig:config I2C_PXA_PCI
> drivers/i2c/busses/Kconfig: def_bool I2C_PXA && X86_32 && PCI && OF
>
> ...meaning that it currently is not being built as a module by anyone.
>
> Lets remove the modular code that is essentially orphaned, so that
> when reading the driver there is no doubt it is builtin-only.
>
> We explicitly disallow a driver unbind, since that doesn't have a
> sensible use case anyway, and it allows us to drop the ".remove"
> code for non-modular drivers.
>
> Since module_pci_driver() uses the same init level priority as
> builtin_pci_driver() the init ordering remains unchanged with
> this commit.
>
> Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.
>
> We also delete the MODULE_LICENSE tag etc. since all that information
> was (or is now) contained at the top of the file in the comments.
>
> Cc: Wolfram Sang <wsa@the-dreams.de>
> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Cc: linux-i2c@vger.kernel.org
> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Applied to for-next, thanks!
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* Re: [Patch V5 2/2] i2c: imx: add low power i2c bus driver
From: Vladimir Zapolskiy @ 2016-11-17 22:36 UTC (permalink / raw)
To: Gao Pan, wsa, u.kleine-koenig, cmo, robh; +Cc: linux-i2c, frank.li, fugang.duan
In-Reply-To: <1479370627-26691-2-git-send-email-pandy.gao@nxp.com>
On 11/17/2016 10:17 AM, Gao Pan wrote:
> This patch adds lpi2c bus driver to support new i.MX products
> which use lpi2c instead of the old imx i2c.
>
> The lpi2c can continue operating in stop mode when an appropriate
> clock is available. It is also designed for low CPU overhead with
> DMA offloading of FIFO register accesses.
>
> Signed-off-by: Gao Pan <pandy.gao@nxp.com>
> Reviewed-by: Fugang Duan <B38611@freescale.com>
From my point of view the code quality is good enough to be included.
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
--
With best wishes,
Vladimir
^ permalink raw reply
* [RFC PATCH v2 6/7] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c, devicetree, linux-iio
In-Reply-To: <1479419289-17553-1-git-send-email-peda@axentia.se>
---
.../devicetree/bindings/i2c/i2c-mux-simple.txt | 91 ++++++++++++++++++++++
1 file changed, 91 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
diff --git a/Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt b/Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
new file mode 100644
index 000000000000..fec1ab39ad64
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
@@ -0,0 +1,91 @@
+Simple I2C Bus Mux
+
+This binding describes an I2C bus multiplexer that uses GPIOs to
+route the I2C signals.
+
+ .-----. .-----.
+ | dev | | dev |
+ .------------. '-----' '-----'
+ | SoC | | |
+ | | .--------+--------'
+ | .------. | .------+ child bus A, on MUX value set to 0
+ | | I2C |-|--| Mux |
+ | '------' | '--+---+ child bus B, on MUX value set to 1
+ | .------. | | '----------+--------+--------.
+ | | MUX- | | | | | |
+ | | Ctrl |-|-----+ .-----. .-----. .-----.
+ | '------' | | dev | | dev | | dev |
+ '------------' '-----' '-----' '-----'
+
+Required properties:
+- compatible: i2c-mux-simple,mux-locked or i2c-mux-simple,parent-locked
+- i2c-parent: The phandle of the I2C bus that this multiplexer's master-side
+ port is connected to.
+- control-muxes : Node of the multiplexer that controls "Mux".
+- control-mux-names : Should be "mux".
+* Standard I2C mux properties. See i2c-mux.txt in this directory.
+* I2C child bus nodes. See i2c-mux.txt in this directory.
+
+Optional properties:
+- idle-state: value to set the muxer to when idle. When no value is
+ given, it defaults to the last value used.
+
+For each i2c child node, an I2C child bus will be created. They will
+be numbered based on their order in the device tree.
+
+Whenever an access is made to a device on a child bus, the value set
+in the relevant node's reg property will be fed to the mux controller.
+
+If an idle state is defined, using the idle-state (optional) property,
+whenever an access is not being made to a device on a child bus, the
+mux controller will be set according to the idle value.
+
+If an idle state is not defined, the most recently used value will be
+left programmed into hardware whenever no access is being made to a
+device on a child bus.
+
+Example:
+ control_i2c_mux: control-i2c-mux {
+ compatible = "mux-gpio";
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+ <&pioA 1 GPIO_ACTIVE_HIGH>;
+ };
+
+ i2c-mux {
+ compatible = "i2c-mux-simple,mux-locked";
+ i2c-parent = <&i2c1>;
+
+ control-muxes = <&control_i2c_mux>;
+ control-mux-names = "mux";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c@1 {
+ reg = <1>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ssd1307: oled@3c {
+ compatible = "solomon,ssd1307fb-i2c";
+ reg = <0x3c>;
+ pwms = <&pwm 4 3000>;
+ reset-gpios = <&gpio2 7 1>;
+ reset-active-low;
+ };
+ };
+
+ i2c@3 {
+ reg = <3>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ pca9555: pca9555@20 {
+ compatible = "nxp,pca9555";
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0x20>;
+ };
+ };
+ };
--
2.1.4
^ permalink raw reply related
* Re: [v5+1,repost] i2c: mux: mellanox: add driver
From: Wolfram Sang @ 2016-11-17 22:20 UTC (permalink / raw)
To: vadimp; +Cc: wsa, peda, linux-i2c, linux-kernel, jiri, Michael Shych
In-Reply-To: <1478813183-134553-1-git-send-email-vadimp@mellanox.com>
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On Thu, Nov 10, 2016 at 09:26:23PM +0000, vadimp@mellanox.com wrote:
> From: Vadim Pasternak <vadimp@mellanox.com>
>
> This driver allows I2C routing controlled through CPLD select registers on
> a wide range of Mellanox systems (CPLD Lattice device).
> MUX selection is provided by digital and analog HW. Analog part is not
> under SW control.
> Digital part is under CPLD control (channel selection/de-selection).
>
> Connectivity schema.
> .---. .-------------.
> | l | | |-- i2cx1 -- i2cx8
> | i |-- i2cn --+--| mlxcpld mux |
> | n | | | |-- i2cy1 -- i2cy8
> | u | | '-------------'
> | x | | |
> '---' '---------'
>
> i2c-mux-mlxpcld does not necessarily require i2c-mlxcpld. It can be used
> along with another bus driver, and still control i2c routing through CPLD
> mux selection, in case the system is equipped with CPLD capable of mux
> selection control.
>
> The Kconfig currently controlling compilation of this code is:
> drivers/i2c/muxes/Kconfig:config I2C_MUX_MLXCPLD
>
> Signed-off-by: Michael Shych <michaelsh@mellanox.com>
> Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
> Reviewed-by: Jiri Pirko <jiri@mellanox.com>
> Acked-by: Peter Rosin <peda@axentia.se>
Applied to for-next, thanks!
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* Re: [v7,1/1] i2c: add master driver for mellanox systems
From: Wolfram Sang @ 2016-11-17 22:15 UTC (permalink / raw)
To: vadimp; +Cc: wsa, linux-i2c, linux-kernel, jiri, Michael Shych
In-Reply-To: <1479388708-37054-1-git-send-email-vadimp@mellanox.com>
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Hi,
thanks for the patch and the prompt reworks. Also thank you to Vladimir
for initial reviews!
> Device supports:
> - Master mode
> - One physical bus
> - Polling mode
Out of interest: is there any interrupt at all?
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 411e3b8..26d05f8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7881,6 +7881,14 @@ W: http://www.mellanox.com
> Q: http://patchwork.ozlabs.org/project/netdev/list/
> F: drivers/net/ethernet/mellanox/mlxsw/
>
> +MELLANOX MLXCPLD I2C DRIVER
> +M: Vadim Pasternak <vadimp@mellanox.com>
> +M: Michael Shych <michaelsh@mellanox.com>
> +L: linux-i2c@vger.kernel.org
> +S: Supported
> +F: drivers/i2c/busses/i2c-mlxcpld.c
> +F: Documentation/i2c/busses/i2c-mlxcpld
> +
No need to change right now, but I think you could simplify all your
drivers in one entry with
F: *mlxcpld*
or something similar to keep MAINTAINERS compact.
> +/**
> + * struct mlxcpld_i2c_curr_xfer - current transaction parameters:
> + * @cmd: command;
> + * @addr_width: address width;
> + * @data_len: data length;
> + * @cmd: command register;
> + * @msg_num: message number;
> + * @msg: pointer to message buffer;
> + */
While I value effort to describe struct members, this is so
self-explaining that I think it could be left out.
> +/**
> + * struct mlxcpld_i2c_priv - private controller data:
> + * @adap: i2c adapter;
> + * @base_addr: base IO address;
> + * @lock: bus access lock;
> + * @xfer: current i2c transfer block;
> + * @dev: device handle;
> + */
ditto
> +/*
> + * Check validity of current i2c message and all transfer.
> + * Calculate also common length of all i2c messages in transfer.
> + */
> +static int mlxcpld_i2c_invalid_len(struct mlxcpld_i2c_priv *priv,
> + const struct i2c_msg *msg, u8 *comm_len)
> +{
> + u8 max_len = msg->flags == I2C_M_RD ? MLXCPLD_I2C_DATA_REG_SZ -
> + MLXCPLD_I2C_MAX_ADDR_LEN : MLXCPLD_I2C_DATA_REG_SZ;
> +
> + if (msg->len > max_len)
> + return -EINVAL;
If you populate a 'struct i2c_adapter_quirks' the core will do this
check for you.
> + *comm_len += msg->len;
> + if (*comm_len > MLXCPLD_I2C_DATA_REG_SZ)
> + return -EINVAL;
> +
> + return 0;
> +}
> +
> +/*
> + * Check validity of received i2c messages parameters.
> + * Returns 0 if OK, other - in case of invalid parameters
> + * or common length of data that should be passed to CPLD
> + */
> +static int mlxcpld_i2c_check_msg_params(struct mlxcpld_i2c_priv *priv,
> + struct i2c_msg *msgs, int num,
> + u8 *comm_len)
> +{
> + int i;
> +
> + if (!num) {
> + dev_err(priv->dev, "Incorrect 0 num of messages\n");
> + return -EINVAL;
> + }
> +
> + if (unlikely(msgs[0].addr > 0x7f)) {
> + dev_err(priv->dev, "Invalid address 0x%03x\n",
> + msgs[0].addr);
> + return -EINVAL;
> + }
> +
> + for (i = 0; i < num; ++i) {
> + if (unlikely(!msgs[i].buf)) {
> + dev_err(priv->dev, "Invalid buf in msg[%d]\n",
> + i);
> + return -EINVAL;
> + }
I was about to write "the core will check this for you", but wow, we are
not good at this... I will try to come up with some patches soon. No
need for you to changes this right now.
...
> + case MLXCPLD_LPCI2C_ACK_IND:
> + if (priv->xfer.cmd != I2C_M_RD)
> + return (priv->xfer.addr_width + priv->xfer.data_len);
> +
> + if (priv->xfer.msg_num == 1)
> + i = 0;
> + else
> + i = 1;
> +
> + if (!priv->xfer.msg[i].buf)
> + return -EINVAL;
> +
> + /*
> + * Actual read data len will be always the same as
> + * requested len. 0xff (line pull-up) will be returned
> + * if slave has no data to return. Thus don't read
> + * MLXCPLD_LPCI2C_NUM_DAT_REG reg from CPLD.
> + */
> + datalen = priv->xfer.data_len;
> +
> + mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_DATA_REG,
> + priv->xfer.msg[i].buf, datalen);
> +
> + return datalen;
> +
> + case MLXCPLD_LPCI2C_NACK_IND:
> + return -EAGAIN;
-EAGAIN is for arbitration lost. -ENXIO is for NACK. See
Documentation/i2c/fault-codes.
What kind of testing have you done with the driver?
Thanks,
Wolfram
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* [RFC PATCH v2 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c, devicetree, linux-iio
In-Reply-To: <1479419289-17553-1-git-send-email-peda@axentia.se>
---
.../bindings/iio/multiplexer/iio-mux.txt | 49 ++++++++++++++++++++++
1 file changed, 49 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
diff --git a/Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt b/Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
new file mode 100644
index 000000000000..df6e4d5cc45e
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
@@ -0,0 +1,49 @@
+IIO multiplexer bindings
+
+If a multiplexer is used to select when hardware signal is fed to
+e.g. an ADC channel, these bindings describe that situation.
+
+Required properties:
+- compatible : "iio-mux"
+- io-channels : Channel node of the parent channel that has multiplexed
+ input.
+- io-channel-names : Should be "parent".
+- control-muxes : Node of the multiplexer that controls the input signal.
+- control-mux-names : Should be "mux".
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Required properties for iio-mux child nodes:
+- reg : The multiplexer number.
+
+Example:
+ control_adc_mux: control-adc-mux {
+ compatible = "mux-gpio";
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+ <&pioA 1 GPIO_ACTIVE_HIGH>;
+ };
+
+ adc-mux {
+ compatible = "iio-mux";
+ io-channels = <&adc 0>;
+ io-channel-names = "parent";
+
+ control-muxes = <&control_adc_mux>;
+ control-mux-names = "mux";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ sync@0 {
+ reg = <0>;
+ };
+
+ in@1 {
+ reg = <1>;
+ };
+
+ system-regulator@2 {
+ reg = <2>;
+ };
+ };
--
2.1.4
^ permalink raw reply related
* Re: [v4, 1/3] i2c: pxa: Add support for the I2C units found in Armada 3700
From: Wolfram Sang @ 2016-11-17 21:54 UTC (permalink / raw)
To: Romain Perier
Cc: linux-i2c, devicetree, Rob Herring, Ian Campbell, Pawel Moll,
Mark Rutland, Kumar Gala, Jason Cooper, Andrew Lunn,
Sebastian Hesselbarth, Gregory Clement, linux-arm-kernel,
Thomas Petazzoni, Nadav Haklai, Omri Itach, Shadi Ammouri,
Yahuda Yitschak, Hanna Hawa, Neta Zur Hershkovits, Igal Liberman
In-Reply-To: <20161109115715.2557-2-romain.perier@free-electrons.com>
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> + [REGS_A3700] = {
> + .ibmr = 0x00,
> + .idbr = 0x04,
> + .icr = 0x08,
> + .isr = 0x0c,
> + .isar = 0x10,
> + },
Can't you reuse REGS_PXA3XX?
> static const struct platform_device_id i2c_pxa_id_table[] = {
> @@ -98,6 +106,7 @@ static const struct platform_device_id i2c_pxa_id_table[] = {
> { "pxa3xx-pwri2c", REGS_PXA3XX },
> { "ce4100-i2c", REGS_CE4100 },
> { "pxa910-i2c", REGS_PXA910 },
> + { "armada-3700-i2c", REGS_A3700 },
So, you declare a platform_device_id here...
> + if (of_device_is_compatible(np, "marvell,armada-3700-i2c")) {
> + i2c->fm_mask = ICR_BUSMODE_FM;
> + i2c->hs_mask = ICR_BUSMODE_HS;
> + } else {
> + i2c->fm_mask = ICR_FM;
> + i2c->hs_mask = ICR_HS;
> + }
... but don't consider this case here?
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply
* [RFC PATCH v2 7/7] i2c: i2c-mux-simple: new driver
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c, devicetree, linux-iio
In-Reply-To: <1479419289-17553-1-git-send-email-peda@axentia.se>
This is a generic simple i2c mux that uses the generic multiplexer
subsystem to do the muxing.
The user can select if the mux is to be mux-locked and parent-locked
as described in Documentation/i2c/i2c-topology.
---
drivers/i2c/muxes/Kconfig | 12 +++
drivers/i2c/muxes/Makefile | 1 +
drivers/i2c/muxes/i2c-mux-simple.c | 168 +++++++++++++++++++++++++++++++++++++
3 files changed, 181 insertions(+)
create mode 100644 drivers/i2c/muxes/i2c-mux-simple.c
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index e280c8ecc0b5..45e80ad2d4ab 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -72,6 +72,18 @@ config I2C_MUX_REG
This driver can also be built as a module. If so, the module
will be called i2c-mux-reg.
+config I2C_MUX_SIMPLE
+ tristate "Simple I2C multiplexer"
+ depends on OF
+ help
+ If you say yes to this option, support will be included for a
+ simple generic I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which is controlled
+ by a generic MUX controller.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-simple.
+
config I2C_DEMUX_PINCTRL
tristate "pinctrl-based I2C demultiplexer"
depends on PINCTRL && OF
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
index 7c267c29b191..eea1fb9e6466 100644
--- a/drivers/i2c/muxes/Makefile
+++ b/drivers/i2c/muxes/Makefile
@@ -10,5 +10,6 @@ obj-$(CONFIG_I2C_MUX_PCA9541) += i2c-mux-pca9541.o
obj-$(CONFIG_I2C_MUX_PCA954x) += i2c-mux-pca954x.o
obj-$(CONFIG_I2C_MUX_PINCTRL) += i2c-mux-pinctrl.o
obj-$(CONFIG_I2C_MUX_REG) += i2c-mux-reg.o
+obj-$(CONFIG_I2C_MUX_SIMPLE) += i2c-mux-simple.o
ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
diff --git a/drivers/i2c/muxes/i2c-mux-simple.c b/drivers/i2c/muxes/i2c-mux-simple.c
new file mode 100644
index 000000000000..6d8ddbc94ecc
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-simple.c
@@ -0,0 +1,168 @@
+/*
+ * Generic simple I2C multiplexer
+ *
+ * Peter Rosin <peda@axentia.se>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/mux.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+struct mux {
+ struct mux_control *control;
+
+ bool do_not_deselect;
+};
+
+static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+ int ret;
+
+ ret = mux_control_select(mux->control, chan);
+ mux->do_not_deselect = ret < 0;
+
+ return ret;
+}
+
+static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+
+ if (mux->do_not_deselect)
+ return 0;
+
+ return mux_control_deselect(mux->control);
+}
+
+static struct i2c_adapter *mux_parent_adapter(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct device_node *parent_np;
+ struct i2c_adapter *parent;
+
+ parent_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!parent_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return ERR_PTR(-ENODEV);
+ }
+ parent = of_find_i2c_adapter_by_node(parent_np);
+ of_node_put(parent_np);
+ if (!parent)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return parent;
+}
+
+static const struct of_device_id i2c_mux_of_match[] = {
+ { .compatible = "i2c-mux-simple,parent-locked",
+ .data = (void *)0, },
+ { .compatible = "i2c-mux-simple,mux-locked",
+ .data = (void *)1, },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_of_match);
+
+static int i2c_mux_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *child;
+ const struct of_device_id *match;
+ struct i2c_mux_core *muxc;
+ struct mux *mux;
+ struct i2c_adapter *parent;
+ int children;
+ int ret;
+
+ if (!np)
+ return -ENODEV;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ mux->control = devm_mux_control_get(dev, "mux");
+ if (IS_ERR(mux->control)) {
+ if (PTR_ERR(mux->control) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get control-mux\n");
+ return PTR_ERR(mux->control);
+ }
+
+ parent = mux_parent_adapter(dev);
+ if (IS_ERR(parent)) {
+ if (PTR_ERR(parent) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get i2c-parent adapter\n");
+ return PTR_ERR(parent);
+ }
+
+ children = of_get_child_count(np);
+
+ muxc = i2c_mux_alloc(parent, dev, children, 0, 0,
+ i2c_mux_select, i2c_mux_deselect);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto err_parent;
+ }
+ muxc->priv = mux;
+
+ platform_set_drvdata(pdev, muxc);
+
+ match = of_match_device(of_match_ptr(i2c_mux_of_match), dev);
+ if (match)
+ muxc->mux_locked = !!of_device_get_match_data(dev);
+
+ for_each_child_of_node(np, child) {
+ u32 chan;
+
+ ret = of_property_read_u32(child, "reg", &chan);
+ if (ret < 0)
+ goto err_children;
+
+ ret = i2c_mux_add_adapter(muxc, 0, chan, 0);
+ if (ret)
+ goto err_children;
+ }
+
+ dev_info(dev, "%d-port mux on %s adapter\n", children, parent->name);
+
+ return 0;
+
+err_children:
+ i2c_mux_del_adapters(muxc);
+err_parent:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static int i2c_mux_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_core *muxc = platform_get_drvdata(pdev);
+
+ i2c_mux_del_adapters(muxc);
+ i2c_put_adapter(muxc->parent);
+
+ return 0;
+}
+
+static struct platform_driver i2c_mux_driver = {
+ .probe = i2c_mux_probe,
+ .remove = i2c_mux_remove,
+ .driver = {
+ .name = "i2c-mux-simple",
+ .of_match_table = i2c_mux_of_match,
+ },
+};
+module_platform_driver(i2c_mux_driver);
+
+MODULE_DESCRIPTION("Simple I2C multiplexer driver");
+MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
+MODULE_LICENSE("GPL v2");
--
2.1.4
^ permalink raw reply related
* [RFC PATCH v2 5/7] iio: multiplexer: new iio category and iio-mux driver
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c, devicetree, linux-iio
In-Reply-To: <1479419289-17553-1-git-send-email-peda@axentia.se>
When a multiplexer changes how an iio device behaves (for example
by feeding different signals to an ADC), this driver can be used
create one virtual iio channel for each multiplexer state.
Depends on the generic multiplexer driver.
---
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/multiplexer/Kconfig | 17 ++
drivers/iio/multiplexer/Makefile | 6 +
drivers/iio/multiplexer/iio-mux.c | 444 ++++++++++++++++++++++++++++++++++++++
5 files changed, 469 insertions(+)
create mode 100644 drivers/iio/multiplexer/Kconfig
create mode 100644 drivers/iio/multiplexer/Makefile
create mode 100644 drivers/iio/multiplexer/iio-mux.c
diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 6743b18194fb..dcb541d0d70e 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -82,6 +82,7 @@ source "drivers/iio/humidity/Kconfig"
source "drivers/iio/imu/Kconfig"
source "drivers/iio/light/Kconfig"
source "drivers/iio/magnetometer/Kconfig"
+source "drivers/iio/multiplexer/Kconfig"
source "drivers/iio/orientation/Kconfig"
if IIO_TRIGGER
source "drivers/iio/trigger/Kconfig"
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 87e4c4369e2f..f9879c29cf6f 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -27,6 +27,7 @@ obj-y += humidity/
obj-y += imu/
obj-y += light/
obj-y += magnetometer/
+obj-y += multiplexer/
obj-y += orientation/
obj-y += potentiometer/
obj-y += pressure/
diff --git a/drivers/iio/multiplexer/Kconfig b/drivers/iio/multiplexer/Kconfig
new file mode 100644
index 000000000000..31cbe4509366
--- /dev/null
+++ b/drivers/iio/multiplexer/Kconfig
@@ -0,0 +1,17 @@
+#
+# Multiplexer drivers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Multiplexers"
+
+config IIO_MUX
+ tristate "IIO multiplexer driver"
+ depends on OF && MUX_GPIO
+ help
+ Say yes here to build support for the IIO multiplexer.
+
+ To compile this driver as a module, choose M here: the
+ module will be called iio-mux.
+
+endmenu
diff --git a/drivers/iio/multiplexer/Makefile b/drivers/iio/multiplexer/Makefile
new file mode 100644
index 000000000000..68be3c4abd07
--- /dev/null
+++ b/drivers/iio/multiplexer/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for industrial I/O multiplexer drivers
+#
+
+# When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_IIO_MUX) += iio-mux.o
diff --git a/drivers/iio/multiplexer/iio-mux.c b/drivers/iio/multiplexer/iio-mux.c
new file mode 100644
index 000000000000..2a8d00da990b
--- /dev/null
+++ b/drivers/iio/multiplexer/iio-mux.c
@@ -0,0 +1,444 @@
+/*
+ * IIO multiplexer driver
+ *
+ * Copyright (C) 2016 Axentia Technologies AB
+ *
+ * Author: Peter Rosin <peda@axentia.se>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/iio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/mux.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+
+struct mux_ext_info_cache {
+ char *data;
+ size_t size;
+};
+
+struct mux_child {
+ u32 state;
+
+ struct mux_ext_info_cache *ext_info_cache;
+};
+
+struct mux {
+ u32 cached_state;
+ struct mux_control *control;
+ struct iio_channel *parent;
+ struct iio_dev *indio_dev;
+ struct iio_chan_spec *c;
+ struct iio_chan_spec_ext_info *ext_info;
+ struct mux_child *child;
+};
+
+static int iio_mux_select(struct mux *mux, int idx)
+{
+ struct mux_child *child = &mux->child[idx];
+ int ret;
+ int i;
+
+ ret = mux_control_select(mux->control, child->state);
+ if (ret < 0) {
+ mux->cached_state = -1;
+ return ret;
+ }
+
+ if (mux->cached_state == child->state)
+ return 0;
+
+ if (mux->c[idx].ext_info) {
+ for (i = 0; mux->c[idx].ext_info[i].name; ++i) {
+ const char *attr = mux->c[idx].ext_info[i].name;
+ struct mux_ext_info_cache *cache;
+
+ cache = &child->ext_info_cache[i];
+
+ if (cache->size < 0)
+ continue;
+
+ ret = iio_write_channel_ext_info(mux->parent, attr,
+ cache->data,
+ cache->size);
+
+ if (ret < 0) {
+ mux_control_deselect(mux->control);
+ mux->cached_state = -1;
+ return ret;
+ }
+ }
+ }
+ mux->cached_state = child->state;
+
+ return 0;
+}
+
+static void iio_mux_deselect(struct mux *mux)
+{
+ mux_control_deselect(mux->control);
+}
+
+static int mux_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct mux *mux = iio_priv(indio_dev);
+ int idx = chan - mux->c;
+ int ret;
+
+ ret = iio_mux_select(mux, idx);
+ if (ret < 0)
+ return ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_read_channel_raw(mux->parent, val);
+ break;
+
+ case IIO_CHAN_INFO_SCALE:
+ ret = iio_read_channel_scale(mux->parent, val, val2);
+ break;
+
+ default:
+ ret = -EINVAL;
+ }
+
+ iio_mux_deselect(mux);
+
+ return ret;
+}
+
+static int mux_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ struct mux *mux = iio_priv(indio_dev);
+ int idx = chan - mux->c;
+ int ret;
+
+ ret = iio_mux_select(mux, idx);
+ if (ret < 0)
+ return ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ *type = IIO_VAL_INT;
+ ret = iio_read_avail_channel_raw(mux->parent, vals, length);
+ break;
+
+ default:
+ ret = -EINVAL;
+ }
+
+ iio_mux_deselect(mux);
+
+ return ret;
+}
+
+static int mux_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct mux *mux = iio_priv(indio_dev);
+ int idx = chan - mux->c;
+ int ret;
+
+ ret = iio_mux_select(mux, idx);
+ if (ret < 0)
+ return ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_write_channel_raw(mux->parent, val);
+ break;
+
+ default:
+ ret = -EINVAL;
+ }
+
+ iio_mux_deselect(mux);
+
+ return ret;
+}
+
+static const struct iio_info mux_info = {
+ .read_raw = mux_read_raw,
+ .read_avail = mux_read_avail,
+ .write_raw = mux_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static ssize_t mux_read_ext_info(struct iio_dev *indio_dev, uintptr_t private,
+ struct iio_chan_spec const *chan, char *buf)
+{
+ struct mux *mux = iio_priv(indio_dev);
+ int idx = chan - mux->c;
+ ssize_t ret;
+
+ ret = iio_mux_select(mux, idx);
+ if (ret < 0)
+ return ret;
+
+ ret = iio_read_channel_ext_info(mux->parent,
+ mux->ext_info[private].name,
+ buf);
+
+ iio_mux_deselect(mux);
+
+ return ret;
+}
+
+static ssize_t mux_write_ext_info(struct iio_dev *indio_dev, uintptr_t private,
+ struct iio_chan_spec const *chan,
+ const char *buf, size_t len)
+{
+ struct device *dev = indio_dev->dev.parent;
+ struct mux *mux = iio_priv(indio_dev);
+ int idx = chan - mux->c;
+ char *new;
+ ssize_t ret;
+
+ ret = iio_mux_select(mux, idx);
+ if (ret < 0)
+ return ret;
+
+ new = devm_kmemdup(dev, buf, len + 1, GFP_KERNEL);
+ if (!new) {
+ iio_mux_deselect(mux);
+ return -ENOMEM;
+ }
+
+ new[len] = 0;
+
+ ret = iio_write_channel_ext_info(mux->parent,
+ mux->ext_info[private].name,
+ buf, len);
+ if (ret < 0) {
+ iio_mux_deselect(mux);
+ devm_kfree(dev, new);
+ return ret;
+ }
+
+ devm_kfree(dev, mux->child[idx].ext_info_cache[private].data);
+ mux->child[idx].ext_info_cache[private].data = new;
+ mux->child[idx].ext_info_cache[private].size = len;
+
+ iio_mux_deselect(mux);
+
+ return ret;
+}
+
+static int mux_configure_channel(struct device *dev, struct mux *mux,
+ struct device_node *child_np, int idx)
+{
+ struct mux_child *child = &mux->child[idx];
+ struct iio_chan_spec *c = &mux->c[idx];
+ const struct iio_chan_spec *pc = mux->parent->channel;
+ char *page;
+ int num_ext_info;
+ int i;
+ int ret;
+
+ c->indexed = 1;
+ c->channel = idx;
+ c->output = pc->output;
+ c->datasheet_name = child_np->name;
+ c->ext_info = mux->ext_info;
+
+ ret = iio_get_channel_type(mux->parent, &c->type);
+ if (ret < 0) {
+ dev_err(dev, "failed to get parent channel type\n");
+ return ret;
+ }
+
+ if (iio_channel_has_info(pc, IIO_CHAN_INFO_RAW))
+ c->info_mask_separate |= BIT(IIO_CHAN_INFO_RAW);
+ if (iio_channel_has_info(pc, IIO_CHAN_INFO_SCALE))
+ c->info_mask_separate |= BIT(IIO_CHAN_INFO_SCALE);
+
+ if (iio_channel_has_available(pc, IIO_CHAN_INFO_RAW))
+ c->info_mask_separate_available |= BIT(IIO_CHAN_INFO_RAW);
+
+ ret = of_property_read_u32(child_np, "reg", &child->state);
+ if (ret < 0) {
+ dev_err(dev, "no reg property for node '%s'\n", child_np->name);
+ return ret;
+ }
+
+ for (i = 0; i < idx; ++i) {
+ if (mux->child[i].state == child->state) {
+ dev_err(dev, "double use of reg %d\n", child->state);
+ return -EINVAL;
+ }
+ }
+
+ num_ext_info = iio_get_channel_ext_info_count(mux->parent);
+ if (num_ext_info) {
+ page = devm_kzalloc(dev, PAGE_SIZE, GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+ }
+ child->ext_info_cache = devm_kzalloc(dev,
+ sizeof(*child->ext_info_cache) *
+ num_ext_info, GFP_KERNEL);
+ for (i = 0; i < num_ext_info; ++i) {
+ child->ext_info_cache[i].size = -1;
+
+ if (!pc->ext_info[i].write)
+ continue;
+ if (!pc->ext_info[i].read)
+ continue;
+
+ ret = iio_read_channel_ext_info(mux->parent,
+ mux->ext_info[i].name,
+ page);
+ if (ret < 0) {
+ dev_err(dev, "failed to get ext_info '%s'\n",
+ pc->ext_info[i].name);
+ return ret;
+ }
+ if (ret >= PAGE_SIZE) {
+ dev_err(dev, "too large ext_info '%s'\n",
+ pc->ext_info[i].name);
+ return -EINVAL;
+ }
+
+ child->ext_info_cache[i].data = devm_kmemdup(dev, page, ret + 1,
+ GFP_KERNEL);
+ child->ext_info_cache[i].data[ret] = 0;
+ child->ext_info_cache[i].size = ret;
+ }
+
+ if (num_ext_info)
+ devm_kfree(dev, page);
+
+ return 0;
+}
+
+static int mux_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = pdev->dev.of_node;
+ struct device_node *child_np;
+ struct iio_dev *indio_dev;
+ struct iio_channel *parent;
+ struct mux *mux;
+ int sizeof_ext_info;
+ int children;
+ int sizeof_priv;
+ int i;
+ int ret;
+
+ if (!np)
+ return -ENODEV;
+
+ parent = devm_iio_channel_get(dev, "parent");
+ if (IS_ERR(parent)) {
+ if (PTR_ERR(parent) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get parent channel\n");
+ return PTR_ERR(parent);
+ }
+
+ sizeof_ext_info = iio_get_channel_ext_info_count(parent);
+ if (sizeof_ext_info) {
+ sizeof_ext_info += 1; /* one extra entry for the sentinel */
+ sizeof_ext_info *= sizeof(*mux->ext_info);
+ }
+
+ children = of_get_child_count(np);
+ if (children <= 0) {
+ dev_err(dev, "not even a single child\n");
+ return -EINVAL;
+ }
+
+ sizeof_priv = sizeof(*mux);
+ sizeof_priv += sizeof(*mux->child) * children;
+ sizeof_priv += sizeof(*mux->c) * children;
+ sizeof_priv += sizeof_ext_info;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof_priv);
+ if (!indio_dev)
+ return -ENOMEM;
+
+ mux = iio_priv(indio_dev);
+ mux->child = (struct mux_child *)(mux + 1);
+ mux->c = (struct iio_chan_spec *)(mux->child + children);
+
+ platform_set_drvdata(pdev, indio_dev);
+
+ mux->parent = parent;
+ mux->cached_state = -1;
+
+ indio_dev->name = dev_name(dev);
+ indio_dev->dev.parent = dev;
+ indio_dev->info = &mux_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = mux->c;
+ indio_dev->num_channels = children;
+ if (sizeof_ext_info) {
+ mux->ext_info = devm_kmemdup(dev,
+ parent->channel->ext_info,
+ sizeof_ext_info, GFP_KERNEL);
+ if (!mux->ext_info)
+ return -ENOMEM;
+
+ for (i = 0; mux->ext_info[i].name; ++i) {
+ if (parent->channel->ext_info[i].read)
+ mux->ext_info[i].read = mux_read_ext_info;
+ if (parent->channel->ext_info[i].write)
+ mux->ext_info[i].write = mux_write_ext_info;
+ mux->ext_info[i].private = i;
+ }
+ }
+
+ i = 0;
+ for_each_child_of_node(np, child_np) {
+ ret = mux_configure_channel(dev, mux, child_np, i);
+ if (ret < 0)
+ return ret;
+ i++;
+ }
+
+ mux->control = devm_mux_control_get(dev, "mux");
+ if (IS_ERR(mux->control)) {
+ if (PTR_ERR(mux->control) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get control-mux\n");
+ return PTR_ERR(mux->control);
+ }
+
+ ret = devm_iio_device_register(dev, indio_dev);
+ if (ret) {
+ dev_err(dev, "failed to register iio device\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id mux_match[] = {
+ { .compatible = "iio-mux" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mux_match);
+
+static struct platform_driver mux_driver = {
+ .probe = mux_probe,
+ .driver = {
+ .name = "iio-mux",
+ .of_match_table = mux_match,
+ },
+};
+module_platform_driver(mux_driver);
+
+MODULE_DESCRIPTION("IIO multiplexer driver");
+MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
+MODULE_LICENSE("GPL v2");
--
2.1.4
^ permalink raw reply related
* [RFC PATCH v2 3/7] iio: inkern: api for manipulating ext_info of iio channels
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-iio-u79uwXL29TY76Z2rM5mHXA
In-Reply-To: <1479419289-17553-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
Extend the inkern api with functions for reading and writing ext_info
of iio channels.
---
drivers/iio/inkern.c | 55 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/iio/consumer.h | 6 +++++
2 files changed, 61 insertions(+)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index cfca17ba2535..a8099b164222 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -850,3 +850,58 @@ int iio_write_channel_raw(struct iio_channel *chan, int val)
return ret;
}
EXPORT_SYMBOL_GPL(iio_write_channel_raw);
+
+int iio_get_channel_ext_info_count(struct iio_channel *chan)
+{
+ const struct iio_chan_spec_ext_info *ext_info;
+ unsigned int i = 0;
+
+ if (!chan->channel->ext_info)
+ return i;
+
+ for (ext_info = chan->channel->ext_info; ext_info->name; ext_info++)
+ ++i;
+
+ return i;
+}
+EXPORT_SYMBOL_GPL(iio_get_channel_ext_info_count);
+
+ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
+ const char *attr, char *buf)
+{
+ const struct iio_chan_spec_ext_info *ext_info;
+
+ if (!chan->channel->ext_info)
+ return -EINVAL;
+
+ for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
+ if (strcmp(attr, ext_info->name))
+ continue;
+
+ return ext_info->read(chan->indio_dev, ext_info->private,
+ chan->channel, buf);
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(iio_read_channel_ext_info);
+
+ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
+ const char *buf, size_t len)
+{
+ const struct iio_chan_spec_ext_info *ext_info;
+
+ if (!chan->channel->ext_info)
+ return -EINVAL;
+
+ for (ext_info = chan->channel->ext_info; ext_info->name; ++ext_info) {
+ if (strcmp(attr, ext_info->name))
+ continue;
+
+ return ext_info->write(chan->indio_dev, ext_info->private,
+ chan->channel, buf, len);
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(iio_write_channel_ext_info);
diff --git a/include/linux/iio/consumer.h b/include/linux/iio/consumer.h
index 9a4f336d8b4a..471dece8729a 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -299,4 +299,10 @@ int iio_read_channel_scale(struct iio_channel *chan, int *val,
int iio_convert_raw_to_processed(struct iio_channel *chan, int raw,
int *processed, unsigned int scale);
+int iio_get_channel_ext_info_count(struct iio_channel *chan);
+ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
+ const char *attr, char *buf);
+ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
+ const char *buf, size_t len);
+
#endif
--
2.1.4
--
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the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply related
* [RFC PATCH v2 2/7] misc: minimal mux subsystem and gpio-based mux controller
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-iio-u79uwXL29TY76Z2rM5mHXA
In-Reply-To: <1479419289-17553-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
When both the iio subsystem and the i2c subsystem wants to update
the same mux, there needs to be some coordination. Invent a new
minimal "mux" subsystem that handles this.
Add a single backend driver for this new subsystem that can
control gpio based multiplexers.
---
drivers/misc/Kconfig | 6 +
drivers/misc/Makefile | 2 +
drivers/misc/mux-core.c | 299 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/misc/mux-gpio.c | 115 +++++++++++++++++++
include/linux/mux.h | 53 +++++++++
5 files changed, 475 insertions(+)
create mode 100644 drivers/misc/mux-core.c
create mode 100644 drivers/misc/mux-gpio.c
create mode 100644 include/linux/mux.h
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 64971baf11fa..9e119bb78d82 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -766,6 +766,12 @@ config PANEL_BOOT_MESSAGE
An empty message will only clear the display at driver init time. Any other
printf()-formatted message is valid with newline and escape codes.
+config MUX_GPIO
+ tristate "GPIO-controlled MUX controller"
+ depends on OF
+ help
+ GPIO-controlled MUX controller
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 31983366090a..92b547bcbac1 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -53,6 +53,8 @@ obj-$(CONFIG_ECHO) += echo/
obj-$(CONFIG_VEXPRESS_SYSCFG) += vexpress-syscfg.o
obj-$(CONFIG_CXL_BASE) += cxl/
obj-$(CONFIG_PANEL) += panel.o
+obj-$(CONFIG_MUX_GPIO) += mux-core.o
+obj-$(CONFIG_MUX_GPIO) += mux-gpio.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_core.o
lkdtm-$(CONFIG_LKDTM) += lkdtm_bugs.o
diff --git a/drivers/misc/mux-core.c b/drivers/misc/mux-core.c
new file mode 100644
index 000000000000..7a8bf003a92c
--- /dev/null
+++ b/drivers/misc/mux-core.c
@@ -0,0 +1,299 @@
+/*
+ * Multiplexer subsystem
+ *
+ * Copyright (C) 2016 Axentia Technologies AB
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) "mux-core: " fmt
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/mux.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+static struct bus_type mux_bus_type = {
+ .name = "mux",
+};
+
+static int __init mux_init(void)
+{
+ return bus_register(&mux_bus_type);
+}
+
+static void __exit mux_exit(void)
+{
+ bus_unregister(&mux_bus_type);
+}
+
+static DEFINE_IDA(mux_ida);
+
+static void mux_control_release(struct device *dev)
+{
+ struct mux_control *mux = to_mux_control(dev);
+
+ ida_simple_remove(&mux_ida, mux->id);
+ kfree(mux);
+}
+
+static struct device_type mux_control_type = {
+ .name = "mux-control",
+ .release = mux_control_release,
+};
+
+/*
+ * Allocate a mux-control, plus an extra memory area for private use
+ * by the caller.
+ */
+struct mux_control *mux_control_alloc(size_t sizeof_priv)
+{
+ struct mux_control *mux;
+
+ mux = kzalloc(sizeof(*mux) + sizeof_priv, GFP_KERNEL);
+ if (!mux)
+ return NULL;
+
+ mux->dev.bus = &mux_bus_type;
+ mux->dev.type = &mux_control_type;
+ device_initialize(&mux->dev);
+ dev_set_drvdata(&mux->dev, mux);
+
+ init_rwsem(&mux->lock);
+ mux->priv = mux + 1;
+
+ mux->id = ida_simple_get(&mux_ida, 0, 0, GFP_KERNEL);
+ if (mux->id < 0) {
+ pr_err("mux-controlX failed to get device id\n");
+ kfree(mux);
+ return NULL;
+ }
+ dev_set_name(&mux->dev, "mux:control%d", mux->id);
+
+ mux->cached_state = -1;
+ mux->idle_state = -1;
+
+ return mux;
+}
+EXPORT_SYMBOL_GPL(mux_control_alloc);
+
+/*
+ * Register the mux-control, thus readying it for use.
+ */
+int mux_control_register(struct mux_control *mux)
+{
+ /* If the calling driver did not initialize of_node, do it here */
+ if (!mux->dev.of_node && mux->dev.parent)
+ mux->dev.of_node = mux->dev.parent->of_node;
+
+ return device_add(&mux->dev);
+}
+EXPORT_SYMBOL_GPL(mux_control_register);
+
+/*
+ * Take the mux-control off-line.
+ */
+void mux_control_unregister(struct mux_control *mux)
+{
+ device_del(&mux->dev);
+}
+EXPORT_SYMBOL_GPL(mux_control_unregister);
+
+/*
+ * Put away the mux-control for good.
+ */
+void mux_control_put(struct mux_control *mux)
+{
+ if (!mux)
+ return;
+ put_device(&mux->dev);
+}
+EXPORT_SYMBOL_GPL(mux_control_put);
+
+static int mux_control_set(struct mux_control *mux, int state)
+{
+ int ret = mux->ops->set(mux, state);
+
+ mux->cached_state = ret < 0 ? -1 : state;
+
+ return ret;
+}
+
+/*
+ * Select the given multiplexer channel. Call mux_control_deselect()
+ * when the operation is complete on the multiplexer channel, and the
+ * multiplexer is free for others to use.
+ */
+int mux_control_select(struct mux_control *mux, int state)
+{
+ int ret;
+
+ if (down_read_trylock(&mux->lock)) {
+ if (mux->cached_state == state)
+ return 0;
+
+ /* Sigh, the mux needs updating... */
+ up_read(&mux->lock);
+ }
+
+ /* ...or it's just contended. */
+ down_write(&mux->lock);
+
+ if (mux->cached_state == state) {
+ /*
+ * Hmmm, someone else changed the mux to my liking.
+ * That makes me wonder how long I waited for nothing...
+ */
+ downgrade_write(&mux->lock);
+ return 0;
+ }
+
+ ret = mux_control_set(mux, state);
+ if (ret < 0) {
+ if (mux->idle_state != -1)
+ mux_control_set(mux, mux->idle_state);
+
+ up_write(&mux->lock);
+ return ret;
+ }
+
+ downgrade_write(&mux->lock);
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(mux_control_select);
+
+/*
+ * Deselect the previously selected multiplexer channel.
+ */
+int mux_control_deselect(struct mux_control *mux)
+{
+ int ret = 0;
+
+ if (mux->idle_state != -1 && mux->cached_state != mux->idle_state)
+ ret = mux_control_set(mux, mux->idle_state);
+
+ up_read(&mux->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mux_control_deselect);
+
+static int of_dev_node_match(struct device *dev, void *data)
+{
+ return dev->of_node == data;
+}
+
+static struct mux_control *of_find_mux_by_node(struct device_node *np)
+{
+ struct device *dev;
+
+ dev = bus_find_device(&mux_bus_type, NULL, np, of_dev_node_match);
+
+ return dev ? to_mux_control(dev) : NULL;
+}
+
+static struct mux_control *of_mux_control_get(struct device_node *np, int index)
+{
+ struct device_node *mux_np;
+ struct mux_control *mux;
+
+ mux_np = of_parse_phandle(np, "control-muxes", index);
+ if (!mux_np)
+ return NULL;
+
+ mux = of_find_mux_by_node(mux_np);
+ of_node_put(mux_np);
+
+ return mux;
+}
+
+/*
+ * Get a named mux.
+ */
+struct mux_control *mux_control_get(struct device *dev, const char *mux_name)
+{
+ struct device_node *np = dev->of_node;
+ struct mux_control *mux;
+ int index;
+
+ index = of_property_match_string(np, "control-mux-names", mux_name);
+ if (index < 0) {
+ dev_err(dev, "failed to get control-mux %s:%s(%i)\n",
+ np->full_name, mux_name ?: "", index);
+ return ERR_PTR(index);
+ }
+
+ mux = of_mux_control_get(np, index);
+ if (!mux)
+ return ERR_PTR(-EPROBE_DEFER);
+
+ return mux;
+}
+EXPORT_SYMBOL_GPL(mux_control_get);
+
+static void devm_mux_control_free(struct device *dev, void *res)
+{
+ struct mux_control *mux = *(struct mux_control **)res;
+
+ mux_control_put(mux);
+}
+
+/*
+ * Get a named mux, with resource management.
+ */
+struct mux_control *devm_mux_control_get(struct device *dev,
+ const char *mux_name)
+{
+ struct mux_control **ptr, *mux;
+
+ ptr = devres_alloc(devm_mux_control_free, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ mux = mux_control_get(dev, mux_name);
+ if (IS_ERR(mux)) {
+ devres_free(ptr);
+ return mux;
+ }
+
+ *ptr = mux;
+ devres_add(dev, ptr);
+
+ return mux;
+}
+EXPORT_SYMBOL_GPL(devm_mux_control_get);
+
+static int devm_mux_control_match(struct device *dev, void *res, void *data)
+{
+ struct mux_control **r = res;
+
+ if (!r || !*r) {
+ WARN_ON(!r || !*r);
+ return 0;
+ }
+
+ return *r == data;
+}
+
+/*
+ * Resource-managed version mux_control_put.
+ */
+void devm_mux_control_put(struct device *dev, struct mux_control *mux)
+{
+ WARN_ON(devres_release(dev, devm_mux_control_free,
+ devm_mux_control_match, mux));
+}
+EXPORT_SYMBOL_GPL(devm_mux_control_put);
+
+subsys_initcall(mux_init);
+module_exit(mux_exit);
+
+MODULE_AUTHOR("Peter Rosin <peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org");
+MODULE_DESCRIPTION("MUX subsystem");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/misc/mux-gpio.c b/drivers/misc/mux-gpio.c
new file mode 100644
index 000000000000..2ddd7fb24078
--- /dev/null
+++ b/drivers/misc/mux-gpio.c
@@ -0,0 +1,115 @@
+/*
+ * GPIO-controlled multiplexer driver
+ *
+ * Copyright (C) 2016 Axentia Technologies AB
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/mux.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+struct mux_gpio {
+ struct gpio_descs *gpios;
+};
+
+static int mux_gpio_set(struct mux_control *mux, int val)
+{
+ struct mux_gpio *mux_gpio = mux->priv;
+ int i;
+
+ for (i = 0; i < mux_gpio->gpios->ndescs; i++)
+ gpiod_set_value_cansleep(mux_gpio->gpios->desc[i],
+ val & (1 << i));
+
+ return 0;
+}
+
+static const struct mux_control_ops mux_gpio_ops = {
+ .set = mux_gpio_set,
+};
+
+static const struct of_device_id mux_gpio_dt_ids[] = {
+ { .compatible = "mux-gpio", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mux_gpio_dt_ids);
+
+static int mux_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = pdev->dev.of_node;
+ struct mux_control *mux;
+ struct mux_gpio *mux_gpio;
+ u32 idle_state;
+ int ret;
+
+ if (!np)
+ return -ENODEV;
+
+ mux = mux_control_alloc(sizeof(*mux_gpio));
+ if (!mux)
+ return -ENOMEM;
+ mux_gpio = mux->priv;
+ mux->dev.parent = dev;
+ mux->ops = &mux_gpio_ops;
+
+ platform_set_drvdata(pdev, mux);
+
+ mux_gpio->gpios = devm_gpiod_get_array(dev, "mux", GPIOD_OUT_LOW);
+ if (IS_ERR(mux_gpio->gpios)) {
+ if (PTR_ERR(mux_gpio->gpios) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get gpios\n");
+ mux_control_put(mux);
+ return PTR_ERR(mux_gpio->gpios);
+ }
+
+ ret = of_property_read_u32(np, "idle-state", &idle_state);
+ if (ret >= 0) {
+ if (idle_state >= (1 << mux_gpio->gpios->ndescs)) {
+ dev_err(dev, "invalid idle-state %u\n", idle_state);
+ return -EINVAL;
+ }
+ mux->idle_state = idle_state;
+ }
+
+ ret = mux_control_register(mux);
+ if (ret < 0) {
+ dev_err(dev, "failed to register mux_control\n");
+ mux_control_put(mux);
+ return ret;
+ }
+
+ return ret;
+}
+
+static int mux_gpio_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mux_control *mux = to_mux_control(dev);
+
+ mux_control_unregister(mux);
+ mux_control_put(mux);
+ return 0;
+}
+
+static struct platform_driver mux_gpio_driver = {
+ .driver = {
+ .name = "mux-gpio",
+ .of_match_table = of_match_ptr(mux_gpio_dt_ids),
+ },
+ .probe = mux_gpio_probe,
+ .remove = mux_gpio_remove,
+};
+module_platform_driver(mux_gpio_driver);
+
+MODULE_AUTHOR("Peter Rosin <peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org");
+MODULE_DESCRIPTION("GPIO-controlled multiplexer driver");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mux.h b/include/linux/mux.h
new file mode 100644
index 000000000000..5b21b8184056
--- /dev/null
+++ b/include/linux/mux.h
@@ -0,0 +1,53 @@
+/*
+ * mux.h - definitions for the multiplexer interface
+ *
+ * Copyright (C) 2016 Axentia Technologies AB
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _LINUX_MUX_H
+#define _LINUX_MUX_H
+
+#include <linux/device.h>
+#include <linux/rwsem.h>
+
+struct mux_control;
+
+struct mux_control_ops {
+ int (*set)(struct mux_control *mux, int reg);
+};
+
+struct mux_control {
+ struct rw_semaphore lock; /* protects the state of the mux */
+
+ struct device dev;
+ int id;
+
+ int cached_state;
+ int idle_state;
+
+ const struct mux_control_ops *ops;
+
+ void *priv;
+};
+
+#define to_mux_control(x) container_of((x), struct mux_control, dev)
+
+struct mux_control *mux_control_alloc(size_t sizeof_priv);
+int mux_control_register(struct mux_control *mux);
+void mux_control_unregister(struct mux_control *mux);
+void mux_control_put(struct mux_control *mux);
+
+int mux_control_select(struct mux_control *mux, int state);
+int mux_control_deselect(struct mux_control *mux);
+
+struct mux_control *mux_control_get(struct device *dev,
+ const char *mux_name);
+struct mux_control *devm_mux_control_get(struct device *dev,
+ const char *mux_name);
+void devm_mux_control_put(struct device *dev, struct mux_control *mux);
+
+#endif /* _LINUX_MUX_H */
--
2.1.4
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^ permalink raw reply related
* [RFC PATCH v2 1/7] dt-bindings: document devicetree bindings for mux-gpio
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-iio-u79uwXL29TY76Z2rM5mHXA
In-Reply-To: <1479419289-17553-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
---
.../devicetree/bindings/misc/mux-gpio.txt | 79 ++++++++++++++++++++++
1 file changed, 79 insertions(+)
create mode 100644 Documentation/devicetree/bindings/misc/mux-gpio.txt
diff --git a/Documentation/devicetree/bindings/misc/mux-gpio.txt b/Documentation/devicetree/bindings/misc/mux-gpio.txt
new file mode 100644
index 000000000000..73699a37824f
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/mux-gpio.txt
@@ -0,0 +1,79 @@
+GPIO-based multiplexer controller bindings
+
+Define what GPIO pins are used to control a multiplexer. Or several
+multiplexers, if the same pins control more than one multiplexer.
+
+Required properties:
+- compatible : "mux-gpio"
+- mux-gpios : list of gpios used to control the multiplexer, least
+ significant bit first.
+
+Optional properties:
+- idle-state : if present, the state the mux will have when idle.
+
+Example:
+ control_mux: control-adc-mux {
+ compatible = "mux-gpio";
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+ <&pioA 1 GPIO_ACTIVE_HIGH>;
+ };
+
+ adc-mux {
+ compatible = "iio-mux";
+ io-channels = <&adc 0>;
+ io-channel-names = "parent";
+
+ control-muxes = <&control_mux>;
+ control-mux-names = "mux";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ sync-1@0 {
+ reg = <0>;
+ };
+
+ in@1 {
+ reg = <1>;
+ };
+
+ out@2 {
+ reg = <2>;
+ };
+
+ sync-2@3 {
+ reg = <3>;
+ };
+ };
+
+ i2c-mux {
+ compatible = "i2c-mux-simple,mux-locked";
+ i2c-parent = <&i2c1>;
+
+ control-muxes = <&control_mux>;
+ control-mux-names = "mux";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ i2c@0 {
+ reg = <0>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ssd1307: oled@3c {
+ /* ... */
+ };
+ };
+
+ i2c@3 {
+ reg = <3>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ pca9555: pca9555@20 {
+ /* ... */
+ };
+ };
+ };
--
2.1.4
^ permalink raw reply related
* [RFC PATCH v2 0/7] mux controller abstraction and iio/i2c muxes
From: Peter Rosin @ 2016-11-17 21:48 UTC (permalink / raw)
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: Peter Rosin, Wolfram Sang, Rob Herring, Mark Rutland,
Jonathan Cameron, Hartmut Knaack, Lars-Peter Clausen,
Peter Meerwald-Stadler, Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-iio-u79uwXL29TY76Z2rM5mHXA
Hi!
This is work in progress, I'm asking for early feedback.
The code depends on the _available work in iio which can
be found in linux-next.
v1 -> v2 changes
- fixup export of mux_control_put reported by kbuild
- drop devicetree iio-ext-info property as noted by Lars-Peter,
and replace the functionality by exposing all ext_info
attributes of the parent channel for each of the muxed
channels. A cache on top of that and each muxed channel
gets its own view of the ext_info of the parent channel.
- implement idle-state for muxes
- clear out the cache on failure in order to force a mux
update on the following use
- cleanup the probe of i2c-mux-simple driver
- fix a bug in the i2c-mux-simple driver, where failure in
the selection of the mux caused a deadlock when the mux
was later unconditionally deselected.
I have a piece of hardware that is using the same 3 GPIO pins
to control four 8-way muxes. Three of them control ADC lines
to an ADS1015 chip with an iio driver, and the last one
controls the SDA line of an i2c bus. We have some deployed
code to handle this, but you do not want to see it or ever
hear about it. I'm not sure why I even mention it. Anyway,
the situation has nagged me to no end for quite some time.
So, after first getting more intimate with the i2c muxing code
and later discovering the drivers/iio/inkern.c file and
writing a couple of drivers making use of it, I came up with
what I think is an acceptable solution; add a generic mux
controller driver that is shared between all instances, and
combine that with an iio mux driver and a new generic i2c mux
driver. The new i2c mux I called "simple" since it is only
hooking the i2c muxing and the new mux controller (much like
the alsa simple card driver does for ASoC).
My initial (private) version didn't add "mux" as a new bus,
but I couldn't get decent type-checking and nice devicetree
integration with that. It does however feel a bit rich to
add a new bus for something as small as mux controllers?
One thing that I would like to do, but don't see a solution
for, is to move the mux control code that is present in
various drivers in drivers/i2c/muxes to this new minimalistic
muxing subsystem, thus converting all present i2c muxes (but
perhaps not gates and arbitrators) to be i2c-mux-simple muxes.
I'm using an rwsem to lock a mux, but that isn't really a
perfect fit. Is there a better locking primitive that I don't
know about that fits better? I had a mutex at one point, but
that didn't allow any concurrent accesses at all. At least
the rwsem allows concurrent access as long as all users
agree on the mux state, but I suspect that the rwsem will
degrade to the mutex situation pretty quickly if there is
any contention.
Also, the "mux" name feels a bit ambitious, there are many muxes
in the world, and this tiny bit of code is probably not good
enough to be a nice fit for all...
This is all very fresh code and only lightly tested, but it
feels very promising! Now, go ahead and rip this to pieces...
Cheers,
Peter
Peter Rosin (7):
dt-bindings: document devicetree bindings for mux-gpio
misc: minimal mux subsystem and gpio-based mux controller
iio: inkern: api for manipulating ext_info of iio channels
dt-bindings: iio: iio-mux: document iio-mux bindings
iio: multiplexer: new iio category and iio-mux driver
dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings
i2c: i2c-mux-simple: new driver
.../devicetree/bindings/i2c/i2c-mux-simple.txt | 91 +++++
.../bindings/iio/multiplexer/iio-mux.txt | 49 +++
.../devicetree/bindings/misc/mux-gpio.txt | 79 ++++
drivers/i2c/muxes/Kconfig | 12 +
drivers/i2c/muxes/Makefile | 1 +
drivers/i2c/muxes/i2c-mux-simple.c | 168 ++++++++
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/inkern.c | 55 +++
drivers/iio/multiplexer/Kconfig | 17 +
drivers/iio/multiplexer/Makefile | 6 +
drivers/iio/multiplexer/iio-mux.c | 444 +++++++++++++++++++++
drivers/misc/Kconfig | 6 +
drivers/misc/Makefile | 2 +
drivers/misc/mux-core.c | 299 ++++++++++++++
drivers/misc/mux-gpio.c | 115 ++++++
include/linux/iio/consumer.h | 6 +
include/linux/mux.h | 53 +++
18 files changed, 1405 insertions(+)
create mode 100644 Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
create mode 100644 Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
create mode 100644 Documentation/devicetree/bindings/misc/mux-gpio.txt
create mode 100644 drivers/i2c/muxes/i2c-mux-simple.c
create mode 100644 drivers/iio/multiplexer/Kconfig
create mode 100644 drivers/iio/multiplexer/Makefile
create mode 100644 drivers/iio/multiplexer/iio-mux.c
create mode 100644 drivers/misc/mux-core.c
create mode 100644 drivers/misc/mux-gpio.c
create mode 100644 include/linux/mux.h
--
2.1.4
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^ permalink raw reply
* Re: [PATCHv7 00/11] i2c: Relax mandatory I2C ID table passing
From: Wolfram Sang @ 2016-11-17 21:15 UTC (permalink / raw)
To: Kieran Bingham
Cc: Lee Jones, linux-i2c, linux-kernel, Javier Martinez Canillas,
sameo
In-Reply-To: <1478522866-29620-1-git-send-email-kieran@bingham.xyz>
[-- Attachment #1: Type: text/plain, Size: 881 bytes --]
On Mon, Nov 07, 2016 at 12:47:35PM +0000, Kieran Bingham wrote:
> Version 7 of this patchset performs a rebase to linux-4.9-rc4 and adjust
> the usage of strncasecmps to sysfs_streq. I have also renamed the
> function i2c_of_match_device_strip_vendor to i2c_of_match_device_sysfs
> which feels more appropriate now.
>
> Retested with successful usage of full compatible strings, and shortened
> device id's based on the vendor prefix being stripped.
>
> Wolfram, for your convenience this series is available as a tagged commit
> at: https://git.kernel.org/pub/scm/linux/kernel/git/kbingham/linux.git
> i2c-dt/v4.9-rc4-probe-conversion-v7, though this includes the TESTPATCH so
> it is not by itself suitable for a merge.
As agreed, I applied this series except the last two patches and
squashing two of the patches into patch two.
Thanks to all involved!
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 819 bytes --]
^ permalink raw reply
* [Patch V5 2/2] i2c: imx: add low power i2c bus driver
From: Gao Pan @ 2016-11-17 8:17 UTC (permalink / raw)
To: wsa, u.kleine-koenig, cmo, robh, vz
Cc: linux-i2c, pandy.gao, frank.li, fugang.duan
In-Reply-To: <1479370627-26691-1-git-send-email-pandy.gao@nxp.com>
This patch adds lpi2c bus driver to support new i.MX products
which use lpi2c instead of the old imx i2c.
The lpi2c can continue operating in stop mode when an appropriate
clock is available. It is also designed for low CPU overhead with
DMA offloading of FIFO register accesses.
Signed-off-by: Gao Pan <pandy.gao@nxp.com>
Reviewed-by: Fugang Duan <B38611@freescale.com>
---
V2:
-stop i2c transfer under the wrong condition
-add timeout check in while() domain
V3:
-fix typo inside commit message and the driver.
V4:
As Vladimir Zapolskiy's review, the version do below changes:
-split devicetree binding with driver
-prepare clk in probe()
-replace "1<<n" BIT(n)
-remove unnecessary variables
-fix typo
-use module_platform_driver()
-use i2c_add_adapter()
V5:
-unprepare clk in lpi2c_imx_remove()
-disable clk when lpi2c_imx_config() fails
-unprepare clk when i2c_add_adapter() fails
drivers/i2c/busses/Kconfig | 10 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-imx-lpi2c.c | 649 +++++++++++++++++++++++++++++++++++++
3 files changed, 660 insertions(+)
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index d252276..7cff9ec 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -597,6 +597,16 @@ config I2C_IMX
This driver can also be built as a module. If so, the module
will be called i2c-imx.
+config I2C_IMX_LPI2C
+ tristate "IMX Low Power I2C interface"
+ depends on ARCH_MXC || COMPILE_TEST
+ help
+ Say Y here if you want to use the Low Power IIC bus controller
+ on the Freescale i.MX processors.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-imx-lpi2c.
+
config I2C_IOP3XX
tristate "Intel IOPx3xx and IXP4xx on-chip I2C interface"
depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IXP4XX || ARCH_IOP13XX
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 29764cc..05195cd 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_I2C_HIX5HD2) += i2c-hix5hd2.o
obj-$(CONFIG_I2C_IBM_IIC) += i2c-ibm_iic.o
obj-$(CONFIG_I2C_IMG) += i2c-img-scb.o
obj-$(CONFIG_I2C_IMX) += i2c-imx.o
+obj-$(CONFIG_I2C_IMX_LPI2C) += i2c-imx-lpi2c.o
obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o
obj-$(CONFIG_I2C_JZ4780) += i2c-jz4780.o
obj-$(CONFIG_I2C_KEMPLD) += i2c-kempld.o
diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
new file mode 100644
index 0000000..af5d1b6
--- /dev/null
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -0,0 +1,649 @@
+/*
+ * This is i.MX low power i2c controller driver.
+ *
+ * Copyright 2016 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#define DRIVER_NAME "imx-lpi2c"
+
+#define LPI2C_PARAM 0x04 /* i2c RX/TX FIFO size */
+#define LPI2C_MCR 0x10 /* i2c contrl register */
+#define LPI2C_MSR 0x14 /* i2c status register */
+#define LPI2C_MIER 0x18 /* i2c interrupt enable */
+#define LPI2C_MCFGR0 0x20 /* i2c master configuration */
+#define LPI2C_MCFGR1 0x24 /* i2c master configuration */
+#define LPI2C_MCFGR2 0x28 /* i2c master configuration */
+#define LPI2C_MCFGR3 0x2C /* i2c master configuration */
+#define LPI2C_MCCR0 0x48 /* i2c master clk configuration */
+#define LPI2C_MCCR1 0x50 /* i2c master clk configuration */
+#define LPI2C_MFCR 0x58 /* i2c master FIFO control */
+#define LPI2C_MFSR 0x5C /* i2c master FIFO status */
+#define LPI2C_MTDR 0x60 /* i2c master TX data register */
+#define LPI2C_MRDR 0x70 /* i2c master RX data register */
+
+/* i2c command */
+#define TRAN_DATA 0X00
+#define RECV_DATA 0X01
+#define GEN_STOP 0X02
+#define RECV_DISCARD 0X03
+#define GEN_START 0X04
+#define START_NACK 0X05
+#define START_HIGH 0X06
+#define START_HIGH_NACK 0X07
+
+#define MCR_MEN BIT(0)
+#define MCR_RST BIT(1)
+#define MCR_DOZEN BIT(2)
+#define MCR_DBGEN BIT(3)
+#define MCR_RTF BIT(8)
+#define MCR_RRF BIT(9)
+#define MSR_TDF BIT(0)
+#define MSR_RDF BIT(1)
+#define MSR_SDF BIT(9)
+#define MSR_NDF BIT(10)
+#define MSR_ALF BIT(11)
+#define MSR_MBF BIT(24)
+#define MSR_BBF BIT(25)
+#define MIER_TDIE BIT(0)
+#define MIER_RDIE BIT(1)
+#define MIER_SDIE BIT(9)
+#define MIER_NDIE BIT(10)
+#define MCFGR1_AUTOSTOP BIT(8)
+#define MCFGR1_IGNACK BIT(9)
+#define MRDR_RXEMPTY BIT(14)
+
+#define I2C_CLK_RATIO 2
+#define CHUNK_DATA 256
+
+#define LPI2C_RX_FIFOSIZE 4
+#define LPI2C_TX_FIFOSIZE 4
+
+#define LPI2C_DEFAULT_RATE 100000
+#define STARDARD_MAX_BITRATE 400000
+#define FAST_MAX_BITRATE 1000000
+#define FAST_PLUS_MAX_BITRATE 3400000
+#define HIGHSPEED_MAX_BITRATE 5000000
+
+enum lpi2c_imx_mode {
+ STANDARD, /* 100+Kbps */
+ FAST, /* 400+Kbps */
+ FAST_PLUS, /* 1.0+Mbps */
+ HS, /* 3.4+Mbps */
+ ULTRA_FAST, /* 5.0+Mbps */
+};
+
+enum lpi2c_imx_pincfg {
+ TWO_PIN_OD,
+ TWO_PIN_OO,
+ TWO_PIN_PP,
+ FOUR_PIN_PP,
+};
+
+struct lpi2c_imx_struct {
+ struct i2c_adapter adapter;
+ struct clk *clk;
+ void __iomem *base;
+ __u8 *rx_buf;
+ __u8 *tx_buf;
+ struct completion complete;
+ unsigned int msglen;
+ unsigned int delivered;
+ unsigned int block_data;
+ unsigned int bitrate;
+ enum lpi2c_imx_mode mode;
+};
+
+static void lpi2c_imx_intctrl(struct lpi2c_imx_struct *lpi2c_imx,
+ unsigned int enable)
+{
+ writel(enable, lpi2c_imx->base + LPI2C_MIER);
+}
+
+static int lpi2c_imx_bus_busy(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned long orig_jiffies = jiffies;
+ unsigned int temp;
+
+ while (1) {
+ temp = readl(lpi2c_imx->base + LPI2C_MSR);
+
+ /* check for arbitration lost, clear if set */
+ if (temp & MSR_ALF) {
+ writel(temp, lpi2c_imx->base + LPI2C_MSR);
+ return -EAGAIN;
+ }
+
+ if (temp & (MSR_BBF | MSR_MBF))
+ break;
+
+ if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
+ dev_dbg(&lpi2c_imx->adapter.dev, "bus not work\n");
+ return -ETIMEDOUT;
+ }
+ schedule();
+ }
+
+ return 0;
+}
+
+static void lpi2c_imx_set_mode(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned int bitrate = lpi2c_imx->bitrate;
+ enum lpi2c_imx_mode mode;
+
+ if (bitrate < STARDARD_MAX_BITRATE)
+ mode = STANDARD;
+ else if (bitrate < FAST_MAX_BITRATE)
+ mode = FAST;
+ else if (bitrate < FAST_PLUS_MAX_BITRATE)
+ mode = FAST_PLUS;
+ else if (bitrate < HIGHSPEED_MAX_BITRATE)
+ mode = HS;
+ else
+ mode = ULTRA_FAST;
+
+ lpi2c_imx->mode = mode;
+}
+
+static int lpi2c_imx_start(struct lpi2c_imx_struct *lpi2c_imx,
+ struct i2c_msg *msgs)
+{
+ unsigned int temp;
+ u8 read;
+
+ temp = readl(lpi2c_imx->base + LPI2C_MCR);
+ temp |= MCR_RRF | MCR_RTF;
+ writel(temp, lpi2c_imx->base + LPI2C_MCR);
+ writel(0x7f00, lpi2c_imx->base + LPI2C_MSR);
+
+ read = msgs->flags & I2C_M_RD;
+ temp = (msgs->addr << 1 | read) | (GEN_START << 8);
+ writel(temp, lpi2c_imx->base + LPI2C_MTDR);
+
+ return lpi2c_imx_bus_busy(lpi2c_imx);
+}
+
+static void lpi2c_imx_stop(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned long orig_jiffies = jiffies;
+ unsigned int temp;
+
+ writel(GEN_STOP << 8, lpi2c_imx->base + LPI2C_MTDR);
+
+ do {
+ temp = readl(lpi2c_imx->base + LPI2C_MSR);
+ if (temp & MSR_SDF)
+ break;
+
+ if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
+ dev_dbg(&lpi2c_imx->adapter.dev, "stop timeout\n");
+ break;
+ }
+ schedule();
+
+ } while (1);
+}
+
+/* CLKLO = I2C_CLK_RATIO * CLKHI, SETHOLD = CLKHI, DATAVD = CLKHI/2 */
+static int lpi2c_imx_config(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ u8 prescale, filt, sethold, clkhi, clklo, datavd;
+ unsigned int clk_rate, clk_cycle;
+ enum lpi2c_imx_pincfg pincfg;
+ unsigned int temp;
+
+ lpi2c_imx_set_mode(lpi2c_imx);
+
+ clk_rate = clk_get_rate(lpi2c_imx->clk);
+ if (lpi2c_imx->mode == HS || lpi2c_imx->mode == ULTRA_FAST)
+ filt = 0;
+ else
+ filt = 2;
+
+ for (prescale = 0; prescale <= 7; prescale++) {
+ clk_cycle = clk_rate / ((1 << prescale) * lpi2c_imx->bitrate)
+ - 3 - (filt >> 1);
+ clkhi = (clk_cycle + I2C_CLK_RATIO) / (I2C_CLK_RATIO + 1);
+ clklo = clk_cycle - clkhi;
+ if (clklo < 64)
+ break;
+ }
+
+ if (prescale > 7)
+ return -EINVAL;
+
+ /* set MCFGR1: PINCFG, PRESCALE, IGNACK */
+ if (lpi2c_imx->mode == ULTRA_FAST)
+ pincfg = TWO_PIN_OO;
+ else
+ pincfg = TWO_PIN_OD;
+ temp = prescale | pincfg << 24;
+
+ if (lpi2c_imx->mode == ULTRA_FAST)
+ temp |= MCFGR1_IGNACK;
+
+ writel(temp, lpi2c_imx->base + LPI2C_MCFGR1);
+
+ /* set MCFGR2: FILTSDA, FILTSCL */
+ temp = (filt << 16) | (filt << 24);
+ writel(temp, lpi2c_imx->base + LPI2C_MCFGR2);
+
+ /* set MCCR: DATAVD, SETHOLD, CLKHI, CLKLO */
+ sethold = clkhi;
+ datavd = clkhi >> 1;
+ temp = datavd << 24 | sethold << 16 | clkhi << 8 | clklo;
+
+ if (lpi2c_imx->mode == HS)
+ writel(temp, lpi2c_imx->base + LPI2C_MCCR1);
+ else
+ writel(temp, lpi2c_imx->base + LPI2C_MCCR0);
+
+ return 0;
+}
+
+static int lpi2c_imx_master_enable(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned int temp;
+ int ret;
+
+ ret = clk_enable(lpi2c_imx->clk);
+ if (ret)
+ return ret;
+
+ temp = MCR_RST;
+ writel(temp, lpi2c_imx->base + LPI2C_MCR);
+ writel(0, lpi2c_imx->base + LPI2C_MCR);
+
+ ret = lpi2c_imx_config(lpi2c_imx);
+ if (ret)
+ goto clk_disable;
+
+ temp = readl(lpi2c_imx->base + LPI2C_MCR);
+ temp |= MCR_MEN;
+ writel(temp, lpi2c_imx->base + LPI2C_MCR);
+
+ return 0;
+
+clk_disable:
+ clk_disable(lpi2c_imx->clk);
+
+ return ret;
+}
+
+static int lpi2c_imx_master_disable(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ u32 temp;
+
+ temp = readl(lpi2c_imx->base + LPI2C_MCR);
+ temp &= ~MCR_MEN;
+ writel(temp, lpi2c_imx->base + LPI2C_MCR);
+
+ clk_disable(lpi2c_imx->clk);
+
+ return 0;
+}
+
+static int lpi2c_imx_msg_complete(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned long timeout;
+
+ timeout = wait_for_completion_timeout(&lpi2c_imx->complete, HZ);
+
+ return timeout ? 0 : -ETIMEDOUT;
+}
+
+static int lpi2c_imx_txfifo_empty(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned long orig_jiffies = jiffies;
+ u32 txcnt;
+
+ do {
+ txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
+
+ if (readl(lpi2c_imx->base + LPI2C_MSR) & MSR_NDF) {
+ dev_dbg(&lpi2c_imx->adapter.dev, "NDF detected\n");
+ return -EIO;
+ }
+
+ if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
+ dev_dbg(&lpi2c_imx->adapter.dev, "txfifo empty timeout\n");
+ return -ETIMEDOUT;
+ }
+ schedule();
+
+ } while (txcnt);
+
+ return 0;
+}
+
+static void lpi2c_imx_set_tx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ writel(LPI2C_TX_FIFOSIZE >> 1, lpi2c_imx->base + LPI2C_MFCR);
+}
+
+static void lpi2c_imx_set_rx_watermark(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned int temp, remaining;
+
+ remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
+
+ if (remaining > (LPI2C_RX_FIFOSIZE >> 1))
+ temp = LPI2C_RX_FIFOSIZE >> 1;
+ else
+ temp = 0;
+
+ writel(temp << 16, lpi2c_imx->base + LPI2C_MFCR);
+}
+
+static void lpi2c_imx_write_txfifo(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned int data, txcnt;
+
+ txcnt = readl(lpi2c_imx->base + LPI2C_MFSR) & 0xff;
+
+ while (txcnt < LPI2C_TX_FIFOSIZE) {
+ if (lpi2c_imx->delivered == lpi2c_imx->msglen)
+ break;
+
+ data = lpi2c_imx->tx_buf[lpi2c_imx->delivered++];
+ writel(data, lpi2c_imx->base + LPI2C_MTDR);
+ txcnt++;
+ }
+
+ if (lpi2c_imx->delivered < lpi2c_imx->msglen)
+ lpi2c_imx_intctrl(lpi2c_imx, MIER_TDIE | MIER_NDIE);
+ else
+ complete(&lpi2c_imx->complete);
+}
+
+static void lpi2c_imx_read_rxfifo(struct lpi2c_imx_struct *lpi2c_imx)
+{
+ unsigned int blocklen, remaining;
+ unsigned int temp, data;
+
+ do {
+ data = readl(lpi2c_imx->base + LPI2C_MRDR);
+ if (data & MRDR_RXEMPTY)
+ break;
+
+ lpi2c_imx->rx_buf[lpi2c_imx->delivered++] = data & 0xff;
+ } while (1);
+
+ /*
+ * First byte is the length of remaining packet in the SMBus block
+ * data read. Add it to msgs->len.
+ */
+ if (lpi2c_imx->block_data) {
+ blocklen = lpi2c_imx->rx_buf[0];
+ lpi2c_imx->msglen += blocklen;
+ }
+
+ remaining = lpi2c_imx->msglen - lpi2c_imx->delivered;
+
+ if (!remaining) {
+ complete(&lpi2c_imx->complete);
+ return;
+ }
+
+ /* not finished, still waiting for rx data */
+ lpi2c_imx_set_rx_watermark(lpi2c_imx);
+
+ /* multiple receive commands */
+ if (lpi2c_imx->block_data) {
+ lpi2c_imx->block_data = 0;
+ temp = remaining;
+ temp |= (RECV_DATA << 8);
+ writel(temp, lpi2c_imx->base + LPI2C_MTDR);
+ } else if (!(lpi2c_imx->delivered & 0xff)) {
+ temp = (remaining > CHUNK_DATA ? CHUNK_DATA : remaining) - 1;
+ temp |= (RECV_DATA << 8);
+ writel(temp, lpi2c_imx->base + LPI2C_MTDR);
+ }
+
+ lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE);
+}
+
+static void lpi2c_imx_write(struct lpi2c_imx_struct *lpi2c_imx,
+ struct i2c_msg *msgs)
+{
+ lpi2c_imx->tx_buf = msgs->buf;
+ lpi2c_imx_set_tx_watermark(lpi2c_imx);
+ lpi2c_imx_write_txfifo(lpi2c_imx);
+}
+
+static void lpi2c_imx_read(struct lpi2c_imx_struct *lpi2c_imx,
+ struct i2c_msg *msgs)
+{
+ unsigned int temp;
+
+ lpi2c_imx->rx_buf = msgs->buf;
+ lpi2c_imx->block_data = msgs->flags & I2C_M_RECV_LEN;
+
+ lpi2c_imx_set_rx_watermark(lpi2c_imx);
+ temp = msgs->len > CHUNK_DATA ? CHUNK_DATA - 1 : msgs->len - 1;
+ temp |= (RECV_DATA << 8);
+ writel(temp, lpi2c_imx->base + LPI2C_MTDR);
+
+ lpi2c_imx_intctrl(lpi2c_imx, MIER_RDIE | MIER_NDIE);
+}
+
+static int lpi2c_imx_xfer(struct i2c_adapter *adapter,
+ struct i2c_msg *msgs, int num)
+{
+ struct lpi2c_imx_struct *lpi2c_imx = i2c_get_adapdata(adapter);
+ unsigned int temp;
+ int i, result;
+
+ result = lpi2c_imx_master_enable(lpi2c_imx);
+ if (result)
+ return result;
+
+ for (i = 0; i < num; i++) {
+ result = lpi2c_imx_start(lpi2c_imx, &msgs[i]);
+ if (result)
+ goto disable;
+
+ /* quick smbus */
+ if (num == 1 && msgs[0].len == 0)
+ goto stop;
+
+ lpi2c_imx->delivered = 0;
+ lpi2c_imx->msglen = msgs[i].len;
+ init_completion(&lpi2c_imx->complete);
+
+ if (msgs[i].flags & I2C_M_RD)
+ lpi2c_imx_read(lpi2c_imx, &msgs[i]);
+ else
+ lpi2c_imx_write(lpi2c_imx, &msgs[i]);
+
+ result = lpi2c_imx_msg_complete(lpi2c_imx);
+ if (result)
+ goto stop;
+
+ if (!(msgs[i].flags & I2C_M_RD)) {
+ result = lpi2c_imx_txfifo_empty(lpi2c_imx);
+ if (result)
+ goto stop;
+ }
+ }
+
+stop:
+ lpi2c_imx_stop(lpi2c_imx);
+
+ temp = readl(lpi2c_imx->base + LPI2C_MSR);
+ if ((temp & MSR_NDF) && !result)
+ result = -EIO;
+
+disable:
+ lpi2c_imx_master_disable(lpi2c_imx);
+
+ dev_dbg(&lpi2c_imx->adapter.dev, "<%s> exit with: %s: %d\n", __func__,
+ (result < 0) ? "error" : "success msg",
+ (result < 0) ? result : num);
+
+ return (result < 0) ? result : num;
+}
+
+static irqreturn_t lpi2c_imx_isr(int irq, void *dev_id)
+{
+ struct lpi2c_imx_struct *lpi2c_imx = dev_id;
+ unsigned int temp;
+
+ lpi2c_imx_intctrl(lpi2c_imx, 0);
+ temp = readl(lpi2c_imx->base + LPI2C_MSR);
+
+ if (temp & MSR_RDF) {
+ lpi2c_imx_read_rxfifo(lpi2c_imx);
+ return IRQ_HANDLED;
+ }
+
+ if (temp & MSR_TDF) {
+ lpi2c_imx_write_txfifo(lpi2c_imx);
+ return IRQ_HANDLED;
+ }
+
+ complete(&lpi2c_imx->complete);
+
+ return IRQ_HANDLED;
+}
+
+static u32 lpi2c_imx_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
+ I2C_FUNC_SMBUS_READ_BLOCK_DATA;
+}
+
+static struct i2c_algorithm lpi2c_imx_algo = {
+ .master_xfer = lpi2c_imx_xfer,
+ .functionality = lpi2c_imx_func,
+};
+
+static const struct of_device_id lpi2c_imx_of_match[] = {
+ { .compatible = "fsl,imx7ulp-lpi2c" },
+ { .compatible = "fsl,imx8dv-lpi2c" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, lpi2c_imx_of_match);
+
+static int lpi2c_imx_probe(struct platform_device *pdev)
+{
+ struct lpi2c_imx_struct *lpi2c_imx;
+ struct resource *res;
+ int irq, ret;
+
+ lpi2c_imx = devm_kzalloc(&pdev->dev, sizeof(*lpi2c_imx), GFP_KERNEL);
+ if (!lpi2c_imx)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ lpi2c_imx->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(lpi2c_imx->base))
+ return PTR_ERR(lpi2c_imx->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ dev_err(&pdev->dev, "can't get irq number\n");
+ return irq;
+ }
+
+ lpi2c_imx->adapter.owner = THIS_MODULE;
+ lpi2c_imx->adapter.algo = &lpi2c_imx_algo;
+ lpi2c_imx->adapter.dev.parent = &pdev->dev;
+ lpi2c_imx->adapter.dev.of_node = pdev->dev.of_node;
+ strlcpy(lpi2c_imx->adapter.name, pdev->name,
+ sizeof(lpi2c_imx->adapter.name));
+
+ lpi2c_imx->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(lpi2c_imx->clk)) {
+ dev_err(&pdev->dev, "can't get I2C peripheral clock\n");
+ return PTR_ERR(lpi2c_imx->clk);
+ }
+
+ ret = of_property_read_u32(pdev->dev.of_node,
+ "clock-frequency", &lpi2c_imx->bitrate);
+ if (ret)
+ lpi2c_imx->bitrate = LPI2C_DEFAULT_RATE;
+
+ ret = devm_request_irq(&pdev->dev, irq, lpi2c_imx_isr, 0,
+ pdev->name, lpi2c_imx);
+ if (ret) {
+ dev_err(&pdev->dev, "can't claim irq %d\n", irq);
+ return ret;
+ }
+
+ i2c_set_adapdata(&lpi2c_imx->adapter, lpi2c_imx);
+ platform_set_drvdata(pdev, lpi2c_imx);
+
+ ret = clk_prepare(lpi2c_imx->clk);
+ if (ret) {
+ dev_err(&pdev->dev, "clk prepare failed %d\n", ret);
+ return ret;
+ }
+
+ ret = i2c_add_adapter(&lpi2c_imx->adapter);
+ if (ret)
+ goto clk_unprepare;
+
+ dev_info(&lpi2c_imx->adapter.dev, "LPI2C adapter registered\n");
+
+ return 0;
+
+clk_unprepare:
+ clk_unprepare(lpi2c_imx->clk);
+
+ return ret;
+}
+
+static int lpi2c_imx_remove(struct platform_device *pdev)
+{
+ struct lpi2c_imx_struct *lpi2c_imx = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&lpi2c_imx->adapter);
+
+ clk_unprepare(lpi2c_imx->clk);
+
+ return 0;
+}
+
+static struct platform_driver lpi2c_imx_driver = {
+ .probe = lpi2c_imx_probe,
+ .remove = lpi2c_imx_remove,
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = lpi2c_imx_of_match,
+ },
+};
+
+module_platform_driver(lpi2c_imx_driver);
+
+MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>");
+MODULE_DESCRIPTION("I2C adapter driver for LPI2C bus");
+MODULE_LICENSE("GPL v2");
--
1.9.1
^ permalink raw reply related
* Re: [RFC PATCH 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings
From: Lars-Peter Clausen @ 2016-11-17 11:40 UTC (permalink / raw)
To: Peter Rosin, linux-kernel
Cc: Wolfram Sang, Rob Herring, Mark Rutland, Jonathan Cameron,
Hartmut Knaack, Peter Meerwald-Stadler, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio
In-Reply-To: <1479340111-1259-5-git-send-email-peda@axentia.se>
On 11/17/2016 12:48 AM, Peter Rosin wrote:
> ---
> .../bindings/iio/multiplexer/iio-mux.txt | 59 ++++++++++++++++++++++
> 1 file changed, 59 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
>
> diff --git a/Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt b/Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
> new file mode 100644
> index 000000000000..2f5c7fc35a42
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
> @@ -0,0 +1,59 @@
> +IIO multiplexer bindings
> +
> +If a multiplexer is used to select when hardware signal is fed to
> +e.g. an ADC channel, these bindings describe that situation.
> +
> +Required properties:
> +- compatible : "iio-mux"
> +- io-channels : Channel node of the parent channel that has multiplexed
> + input.
> +- io-channel-names : Should be "parent".
> +- control-muxes : Node of the multiplexer that controls the input signal.
> +- control-mux-names : Should be "mux".
> +- #address-cells = <1>;
> +- #size-cells = <0>;
> +
> +Required properties for iio-mux child nodes:
> +- reg : The multiplexer number.
> +
> +Optional properties for iio-mux child nodes:
> +- iio-ext-info : Array of string pairs, the first item in each pair is the
> + iio ext_info attribute name, and the second item in each
> + pair is the iio ext_info value for that attribute. The
> + mux will write these ext_info values to the corresponding
> + ext_info attributes on every multiplexer switch.
This can't go into the devicetree in its current form as it exposes
implementation details of the Linux kernel drivers.
^ permalink raw reply
* [patch v7 1/1] i2c: add master driver for mellanox systems
From: vadimp @ 2016-11-17 13:18 UTC (permalink / raw)
To: wsa; +Cc: linux-i2c, linux-kernel, jiri, Vadim Pasternak, Michael Shych
From: Vadim Pasternak <vadimp@mellanox.com>
Device driver for Mellanox I2C controller logic, implemented in Lattice
CPLD device.
Device supports:
- Master mode
- One physical bus
- Polling mode
The Kconfig currently controlling compilation of this code is:
drivers/i2c/busses/Kconfig:config I2C_MLXCPLD
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
---
v6->v7
Comments pointed out by Peter:
- Fix grammar in doc file;
- Fix description for CMD in doc file;
- Fix grammar for NUM_DATA, DATAx in doc file;
- Rename mlxcpld_i2c_curr_transf to mlxcpld_i2c_curr_xfer;
- Make code in mlxcpld_i2c_lpc_write_buf more readable and
mlxcpld_i2c_lpc_read_buf, compact and elegant;
- Fix multiline comments;
v5->v6:
Comments pointed out by Vladimir:
- Drop the line with module path from the header;
- In description of mlxcpld_i2c_priv remove lpc_gen_dec_reg asnd dev_id;
- In mlxcpld_i2c_priv change type of the filed base_addr to u16 for
the alignment with in/out and remove unused dev_id;
- Fix misspelling in comment for mlxcpld_i2c_invalid_len;
- Remove comment regarding EBUSY return in mlxcpld_i2c_check_busy;
- Use sizeof of the target storage in allocation in probe routine;
v4->v5:
Comments pointed out by Vladimir:
- Remove "default n" from Kconfig;
- Fix the comments for timeout and pool time;
- Optimize error flow in mlxcpld_i2c_probe;
v3->v4:
Comments pointed out by Vladimir:
- Set default to no in Kconfig;
- Make mlxcpld_i2c_plat_dev static and add empty line before the
declaration;
- In function mlxcpld_i2c_invalid_len remove (msg->len < 0), since len is
unsigned;
- Remove unused symbol mlxcpld_i2c_plat_dev;
- Remove extra spaces in comments to mlxcpld_i2c_check_msg_params;
- Remove unnecessary round braces in mlxcpld_i2c_set_transf_data;
- Remove the assignment of 'i' variable in mlxcpld_i2c_wait_for_tc;
- Add extra line in mlxcpld_i2c_xfer;
- Move assignment of the adapter's fields retries and nr inside
mlxcpld_i2c_adapter declaration;
v2->v3:
Comments pointed out by Vladimir:
- Use tab symbol as indentation in Kconfig
- Add the Kconfig section preserving the alphabetical order - added
within "Other I2C/SMBus bus drivers" after I2C_ELEKTOR (but after this
sections others are not follow alphabetical);
- Change license to dual;
- Replace ADRR with ADDR in macros;
- Remove unused macros: MLXCPLD_LPCI2C_LPF_DFLT,
MLXCPLD_LPCI2C_HALF_CYC_100, MLXCPLD_LPCI2C_I2C_HOLD_100,
MLXCPLD_LPCI2C_HALF_CYC_REG, MLXCPLD_LPCI2C_I2C_HOLD_REG;
- Fix checkpatch warnings (**/ and the end of comment);
- Add empty line before structures mlxcpld_i2c_regs,
mlxcpld_i2c_curr_transf, mlxcpld_i2c_priv;
- Remove unused structure mlxcpld_i2c_regs;
- Remove from mlxcpld_i2c_priv the next fields:
retr_num, poll_time, block_sz, xfer_to; use instead macros
respectively: MLXCPLD_I2C_RETR_NUM, MLXCPLD_I2C_POLL_TIME,
MLXCPLD_I2C_DATA_REG_SZ, MLXCPLD_I2C_XFER_TO;
- In mlxcpld_i2c_invalid_len remove unnecessary else;
- Optimize mlxcpld_i2c_set_transf_data;
- mlxcpld_i2c_reset - add empty lines after/before mutex
lock/unlock;
- mlxcpld_i2c_wait_for_free - cover case timeout is equal
MLXCPLD_I2C_XFER_TO;
- mlxcpld_i2c_wait_for_tc:
- Do not assign err in declaration (also err is removed);
- Insert empty line before case MLXCPLD_LPCI2C_ACK_IND;
- inside case MLXCPLD_LPCI2C_ACK_IND - avoid unnecessary
indentation;
- Remove case MLXCPLD_LPCI2C_ERR_IND and remove this macro;
- Add empty lines in mlxcpld_i2c_xfer before/after mutex_lock/
mutex_unlock;
- In mlxcpld_i2c_probe add emtpy line after platform_set_drvdata;
- Replace platfrom handle pdev in mlxcpld_i2c_priv with the pointer
to the structure device;
- Place assignment of base_addr near the others;
- Enclose e-mail with <>;
Fixes added by Vadim:
- Change structure description format according to
Documentation/kernel-documentation.rst guideline;
- mlxcpld_i2c_wait_for_tc: return error if status reaches default case;
v1->v2
Fixes added by Vadim:
- Put new record in Makefile in alphabetic order;
- Remove http://www.mellanox.com from MAINTAINERS record;
---
Documentation/i2c/busses/i2c-mlxcpld | 47 +++
MAINTAINERS | 8 +
drivers/i2c/busses/Kconfig | 11 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-mlxcpld.c | 540 +++++++++++++++++++++++++++++++++++
5 files changed, 607 insertions(+)
create mode 100644 Documentation/i2c/busses/i2c-mlxcpld
create mode 100644 drivers/i2c/busses/i2c-mlxcpld.c
diff --git a/Documentation/i2c/busses/i2c-mlxcpld b/Documentation/i2c/busses/i2c-mlxcpld
new file mode 100644
index 0000000..4e46c44
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-mlxcpld
@@ -0,0 +1,47 @@
+Driver i2c-mlxcpld
+
+Author: Michael Shych <michaelsh@mellanox.com>
+
+This is the Mellanox I2C controller logic, implemented in Lattice CPLD
+device.
+Device supports:
+ - Master mode.
+ - One physical bus.
+ - Polling mode.
+
+This controller is equipped within the next Mellanox systems:
+"msx6710", "msx6720", "msb7700", "msn2700", "msx1410", "msn2410", "msb7800",
+"msn2740", "msn2100".
+
+The next transaction types are supported:
+ - Receive Byte/Block.
+ - Send Byte/Block.
+ - Read Byte/Block.
+ - Write Byte/Block.
+
+Registers:
+CTRL 0x1 - control reg.
+ Resets all the registers.
+HALF_CYC 0x4 - cycle reg.
+ Configure the width of I2C SCL half clock cycle (in 4 LPC_CLK
+ units).
+I2C_HOLD 0x5 - hold reg.
+ OE (output enable) is delayed by value set to this register
+ (in LPC_CLK units)
+CMD 0x6 - command reg.
+ Bit 0, 0 = write, 1 = read.
+ Bits [7:1] - the 7bit Address of the I2C device.
+ It should be written last as it triggers an I2C transaction.
+NUM_DATA 0x7 - data size reg.
+ Number of data bytes to write in read transaction
+NUM_ADDR 0x8 - address reg.
+ Number of address bytes to write in read transaction.
+STATUS 0x9 - status reg.
+ Bit 0 - transaction is completed.
+ Bit 4 - ACK/NACK.
+DATAx 0xa - 0x54 - 68 bytes data buffer regs.
+ For write transaction address is specified in four first bytes
+ (DATA1 - DATA4), data starting from DATA4.
+ For read transactions address is sent in a separate transaction and
+ specified in the four first bytes (DATA0 - DATA3). Data is read
+ starting from DATA0.
diff --git a/MAINTAINERS b/MAINTAINERS
index 411e3b8..26d05f8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7881,6 +7881,14 @@ W: http://www.mellanox.com
Q: http://patchwork.ozlabs.org/project/netdev/list/
F: drivers/net/ethernet/mellanox/mlxsw/
+MELLANOX MLXCPLD I2C DRIVER
+M: Vadim Pasternak <vadimp@mellanox.com>
+M: Michael Shych <michaelsh@mellanox.com>
+L: linux-i2c@vger.kernel.org
+S: Supported
+F: drivers/i2c/busses/i2c-mlxcpld.c
+F: Documentation/i2c/busses/i2c-mlxcpld
+
MELLANOX MLXCPLD LED DRIVER
M: Vadim Pasternak <vadimp@mellanox.com>
L: linux-leds@vger.kernel.org
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index d252276..6399cea 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1150,6 +1150,17 @@ config I2C_ELEKTOR
This support is also available as a module. If so, the module
will be called i2c-elektor.
+config I2C_MLXCPLD
+ tristate "Mellanox I2C driver"
+ depends on X86_64
+ help
+ This exposes the Mellanox platform I2C busses to the linux I2C layer
+ for X86 based systems.
+ Controller is implemented as CPLD logic.
+
+ This driver can also be built as a module. If so, the module will be
+ called as i2c-mlxcpld.
+
config I2C_PCA_ISA
tristate "PCA9564/PCA9665 on an ISA bus"
depends on ISA
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 29764cc..645bf08 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -116,6 +116,7 @@ obj-$(CONFIG_I2C_BCM_KONA) += i2c-bcm-kona.o
obj-$(CONFIG_I2C_BRCMSTB) += i2c-brcmstb.o
obj-$(CONFIG_I2C_CROS_EC_TUNNEL) += i2c-cros-ec-tunnel.o
obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o
+obj-$(CONFIG_I2C_MLXCPLD) += i2c-mlxcpld.o
obj-$(CONFIG_I2C_OPAL) += i2c-opal.o
obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o
obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o
diff --git a/drivers/i2c/busses/i2c-mlxcpld.c b/drivers/i2c/busses/i2c-mlxcpld.c
new file mode 100644
index 0000000..9310c77
--- /dev/null
+++ b/drivers/i2c/busses/i2c-mlxcpld.c
@@ -0,0 +1,540 @@
+/*
+ * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016 Michael Shych <michaels@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/* General defines */
+#define MLXPLAT_CPLD_LPC_I2C_BASE_ADDR 0x2000
+#define MLXCPLD_I2C_DEVICE_NAME "i2c_mlxcpld"
+#define MLXCPLD_I2C_VALID_FLAG (I2C_M_RECV_LEN | I2C_M_RD)
+#define MLXCPLD_I2C_BUS_NUM 1
+#define MLXCPLD_I2C_DATA_REG_SZ 36
+#define MLXCPLD_I2C_MAX_ADDR_LEN 4
+#define MLXCPLD_I2C_RETR_NUM 2
+#define MLXCPLD_I2C_XFER_TO 500000 /* usec */
+#define MLXCPLD_I2C_POLL_TIME 2000 /* usec */
+
+/* LPC I2C registers */
+#define MLXCPLD_LPCI2C_LPF_REG 0x0
+#define MLXCPLD_LPCI2C_CTRL_REG 0x1
+#define MLXCPLD_LPCI2C_HALF_CYC_REG 0x4
+#define MLXCPLD_LPCI2C_I2C_HOLD_REG 0x5
+#define MLXCPLD_LPCI2C_CMD_REG 0x6
+#define MLXCPLD_LPCI2C_NUM_DAT_REG 0x7
+#define MLXCPLD_LPCI2C_NUM_ADDR_REG 0x8
+#define MLXCPLD_LPCI2C_STATUS_REG 0x9
+#define MLXCPLD_LPCI2C_DATA_REG 0xa
+
+/* LPC I2C masks and parametres */
+#define MLXCPLD_LPCI2C_RST_SEL_MASK 0x1
+#define MLXCPLD_LPCI2C_TRANS_END 0x1
+#define MLXCPLD_LPCI2C_STATUS_NACK 0x10
+#define MLXCPLD_LPCI2C_NO_IND 0
+#define MLXCPLD_LPCI2C_ACK_IND 1
+#define MLXCPLD_LPCI2C_NACK_IND 2
+
+/**
+ * struct mlxcpld_i2c_curr_xfer - current transaction parameters:
+ * @cmd: command;
+ * @addr_width: address width;
+ * @data_len: data length;
+ * @cmd: command register;
+ * @msg_num: message number;
+ * @msg: pointer to message buffer;
+ */
+
+struct mlxcpld_i2c_curr_xfer {
+ u8 cmd;
+ u8 addr_width;
+ u8 data_len;
+ u8 msg_num;
+ struct i2c_msg *msg;
+};
+
+/**
+ * struct mlxcpld_i2c_priv - private controller data:
+ * @adap: i2c adapter;
+ * @base_addr: base IO address;
+ * @lock: bus access lock;
+ * @xfer: current i2c transfer block;
+ * @dev: device handle;
+ */
+
+struct mlxcpld_i2c_priv {
+ struct i2c_adapter adap;
+ u32 base_addr;
+ struct mutex lock;
+ struct mlxcpld_i2c_curr_xfer xfer;
+ struct device *dev;
+};
+
+static void mlxcpld_i2c_lpc_write_buf(u8 *data, u8 len, u32 addr)
+{
+ int i;
+
+ for (i = 0; i < len - len % 4; i += 4)
+ outl(*(u32 *)(data + i), addr + i);
+ for (; i < len; ++i)
+ outb(*(data + i), addr + i);
+}
+
+static void mlxcpld_i2c_lpc_read_buf(u8 *data, u8 len, u32 addr)
+{
+ int i;
+
+ for (i = 0; i < len - len % 4; i += 4)
+ *(u32 *)(data + i) = inl(addr + i);
+ for (; i < len; ++i)
+ *(data + i) = inb(addr + i);
+}
+
+static void mlxcpld_i2c_read_comm(struct mlxcpld_i2c_priv *priv, u8 offs,
+ u8 *data, u8 datalen)
+{
+ u32 addr = priv->base_addr + offs;
+
+ switch (datalen) {
+ case 1:
+ *(data) = inb(addr);
+ break;
+ case 2:
+ *((u16 *)data) = inw(addr);
+ break;
+ case 3:
+ *((u16 *)data) = inw(addr);
+ *(data + 2) = inb(addr + 2);
+ break;
+ case 4:
+ *((u32 *)data) = inl(addr);
+ break;
+ default:
+ mlxcpld_i2c_lpc_read_buf(data, datalen, addr);
+ break;
+ }
+}
+
+static void mlxcpld_i2c_write_comm(struct mlxcpld_i2c_priv *priv, u8 offs,
+ u8 *data, u8 datalen)
+{
+ u32 addr = priv->base_addr + offs;
+
+ switch (datalen) {
+ case 1:
+ outb(*(data), addr);
+ break;
+ case 2:
+ outw(*((u16 *)data), addr);
+ break;
+ case 3:
+ outw(*((u16 *)data), addr);
+ outb(*(data + 2), addr + 2);
+ break;
+ case 4:
+ outl(*((u32 *)data), addr);
+ break;
+ default:
+ mlxcpld_i2c_lpc_write_buf(data, datalen, addr);
+ break;
+ }
+}
+
+/*
+ * Check validity of current i2c message and all transfer.
+ * Calculate also common length of all i2c messages in transfer.
+ */
+static int mlxcpld_i2c_invalid_len(struct mlxcpld_i2c_priv *priv,
+ const struct i2c_msg *msg, u8 *comm_len)
+{
+ u8 max_len = msg->flags == I2C_M_RD ? MLXCPLD_I2C_DATA_REG_SZ -
+ MLXCPLD_I2C_MAX_ADDR_LEN : MLXCPLD_I2C_DATA_REG_SZ;
+
+ if (msg->len > max_len)
+ return -EINVAL;
+
+ *comm_len += msg->len;
+ if (*comm_len > MLXCPLD_I2C_DATA_REG_SZ)
+ return -EINVAL;
+
+ return 0;
+}
+
+/*
+ * Check validity of received i2c messages parameters.
+ * Returns 0 if OK, other - in case of invalid parameters
+ * or common length of data that should be passed to CPLD
+ */
+static int mlxcpld_i2c_check_msg_params(struct mlxcpld_i2c_priv *priv,
+ struct i2c_msg *msgs, int num,
+ u8 *comm_len)
+{
+ int i;
+
+ if (!num) {
+ dev_err(priv->dev, "Incorrect 0 num of messages\n");
+ return -EINVAL;
+ }
+
+ if (unlikely(msgs[0].addr > 0x7f)) {
+ dev_err(priv->dev, "Invalid address 0x%03x\n",
+ msgs[0].addr);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < num; ++i) {
+ if (unlikely(!msgs[i].buf)) {
+ dev_err(priv->dev, "Invalid buf in msg[%d]\n",
+ i);
+ return -EINVAL;
+ }
+ if (unlikely(msgs[0].addr != msgs[i].addr)) {
+ dev_err(priv->dev, "Invalid addr in msg[%d]\n",
+ i);
+ return -EINVAL;
+ }
+ if (unlikely(mlxcpld_i2c_invalid_len(priv, &msgs[i],
+ comm_len))) {
+ dev_err(priv->dev, "Invalid len %d msg[%d], addr 0x%x, lag %u\n",
+ msgs[i].len, i, msgs[i].addr, msgs[i].flags);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * Check if transfer is completed and status of operation.
+ * Returns 0 - transfer completed (both ACK or NACK),
+ * negative - transfer isn't finished.
+ */
+static int mlxcpld_i2c_check_status(struct mlxcpld_i2c_priv *priv, int *status)
+{
+ u8 val;
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_STATUS_REG, &val, 1);
+
+ if (val & MLXCPLD_LPCI2C_TRANS_END) {
+ if (val & MLXCPLD_LPCI2C_STATUS_NACK)
+ /*
+ * The slave is unable to accept the data. No such
+ * slave, command not understood, or unable to accept
+ * any more data.
+ */
+ *status = MLXCPLD_LPCI2C_NACK_IND;
+ else
+ *status = MLXCPLD_LPCI2C_ACK_IND;
+ return 0;
+ }
+ *status = MLXCPLD_LPCI2C_NO_IND;
+
+ return -EIO;
+}
+
+static void mlxcpld_i2c_set_transf_data(struct mlxcpld_i2c_priv *priv,
+ struct i2c_msg *msgs, int num,
+ u8 comm_len)
+{
+ priv->xfer.msg = msgs;
+ priv->xfer.msg_num = num;
+
+ /*
+ * All upper layers currently are never use transfer with more than
+ * 2 messages. Actually, it's also not so relevant in Mellanox systems
+ * because of HW limitation. Max size of transfer is o more than 20B
+ * in current x86 LPCI2C bridge.
+ */
+ priv->xfer.cmd = msgs[num - 1].flags & I2C_M_RD;
+
+ if (priv->xfer.cmd == I2C_M_RD && comm_len != msgs[0].len) {
+ priv->xfer.addr_width = msgs[0].len;
+ priv->xfer.data_len = comm_len - priv->xfer.addr_width;
+ } else {
+ priv->xfer.addr_width = 0;
+ priv->xfer.data_len = comm_len;
+ }
+}
+
+/* Reset CPLD LPCI2C block */
+static void mlxcpld_i2c_reset(struct mlxcpld_i2c_priv *priv)
+{
+ u8 val;
+
+ mutex_lock(&priv->lock);
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_CTRL_REG, &val, 1);
+ val &= ~MLXCPLD_LPCI2C_RST_SEL_MASK;
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_CTRL_REG, &val, 1);
+
+ mutex_unlock(&priv->lock);
+}
+
+/* Make sure the CPLD is ready to start transmitting. */
+static int mlxcpld_i2c_check_busy(struct mlxcpld_i2c_priv *priv)
+{
+ u8 val;
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_STATUS_REG, &val, 1);
+
+ if (val & MLXCPLD_LPCI2C_TRANS_END)
+ return 0;
+
+ return -EIO;
+}
+
+static int mlxcpld_i2c_wait_for_free(struct mlxcpld_i2c_priv *priv)
+{
+ int timeout = 0;
+
+ do {
+ if (!mlxcpld_i2c_check_busy(priv))
+ break;
+ usleep_range(MLXCPLD_I2C_POLL_TIME / 2, MLXCPLD_I2C_POLL_TIME);
+ timeout += MLXCPLD_I2C_POLL_TIME;
+ } while (timeout <= MLXCPLD_I2C_XFER_TO);
+
+ if (timeout > MLXCPLD_I2C_XFER_TO)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+/*
+ * Wait for master transfer to complete.
+ * It puts current process to sleep until we get interrupt or timeout expires.
+ * Returns the number of transferred or read bytes or error (<0).
+ */
+static int mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv *priv)
+{
+ int status, i, timeout = 0;
+ u8 datalen;
+
+ do {
+ usleep_range(MLXCPLD_I2C_POLL_TIME / 2, MLXCPLD_I2C_POLL_TIME);
+ if (!mlxcpld_i2c_check_status(priv, &status))
+ break;
+ timeout += MLXCPLD_I2C_POLL_TIME;
+ } while (status == 0 && timeout < MLXCPLD_I2C_XFER_TO);
+
+ switch (status) {
+ case MLXCPLD_LPCI2C_NO_IND:
+ return -ETIMEDOUT;
+
+ case MLXCPLD_LPCI2C_ACK_IND:
+ if (priv->xfer.cmd != I2C_M_RD)
+ return (priv->xfer.addr_width + priv->xfer.data_len);
+
+ if (priv->xfer.msg_num == 1)
+ i = 0;
+ else
+ i = 1;
+
+ if (!priv->xfer.msg[i].buf)
+ return -EINVAL;
+
+ /*
+ * Actual read data len will be always the same as
+ * requested len. 0xff (line pull-up) will be returned
+ * if slave has no data to return. Thus don't read
+ * MLXCPLD_LPCI2C_NUM_DAT_REG reg from CPLD.
+ */
+ datalen = priv->xfer.data_len;
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_DATA_REG,
+ priv->xfer.msg[i].buf, datalen);
+
+ return datalen;
+
+ case MLXCPLD_LPCI2C_NACK_IND:
+ return -EAGAIN;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static void mlxcpld_i2c_xfer_msg(struct mlxcpld_i2c_priv *priv)
+{
+ int i, len = 0;
+ u8 cmd;
+
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_DAT_REG,
+ &priv->xfer.data_len, 1);
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_ADDR_REG,
+ &priv->xfer.addr_width, 1);
+
+ for (i = 0; i < priv->xfer.msg_num; i++) {
+ if ((priv->xfer.msg[i].flags & I2C_M_RD) != I2C_M_RD) {
+ /* Don't write to CPLD buffer in read transaction */
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_DATA_REG +
+ len, priv->xfer.msg[i].buf,
+ priv->xfer.msg[i].len);
+ len += priv->xfer.msg[i].len;
+ }
+ }
+
+ /*
+ * Set target slave address with command for master transfer.
+ * It should be latest executed function before CPLD transaction.
+ */
+ cmd = (priv->xfer.msg[0].addr << 1) | priv->xfer.cmd;
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_CMD_REG, &cmd, 1);
+}
+
+/*
+ * Generic lpc-i2c transfer.
+ * Returns the number of processed messages or error (<0).
+ */
+static int mlxcpld_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct mlxcpld_i2c_priv *priv = i2c_get_adapdata(adap);
+ u8 comm_len = 0;
+ int err;
+
+ err = mlxcpld_i2c_check_msg_params(priv, msgs, num, &comm_len);
+ if (err) {
+ dev_err(priv->dev, "Incorrect message\n");
+ return err;
+ }
+
+ /* Check bus state */
+ if (mlxcpld_i2c_wait_for_free(priv)) {
+ dev_err(priv->dev, "LPCI2C bridge is busy\n");
+
+ /*
+ * Usually it means something serious has happened.
+ * We can not have unfinished previous transfer
+ * so it doesn't make any sense to try to stop it.
+ * Probably we were not able to recover from the
+ * previous error.
+ * The only reasonable thing - is soft reset.
+ */
+ mlxcpld_i2c_reset(priv);
+ if (mlxcpld_i2c_check_busy(priv)) {
+ dev_err(priv->dev, "LPCI2C bridge is busy after reset\n");
+ return -EIO;
+ }
+ }
+
+ mlxcpld_i2c_set_transf_data(priv, msgs, num, comm_len);
+
+ mutex_lock(&priv->lock);
+
+ /* Do real transfer. Can't fail */
+ mlxcpld_i2c_xfer_msg(priv);
+
+ /* Wait for transaction complete */
+ err = mlxcpld_i2c_wait_for_tc(priv);
+
+ mutex_unlock(&priv->lock);
+
+ return err < 0 ? err : num;
+}
+
+static u32 mlxcpld_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm mlxcpld_i2c_algo = {
+ .master_xfer = mlxcpld_i2c_xfer,
+ .functionality = mlxcpld_i2c_func
+};
+
+static struct i2c_adapter mlxcpld_i2c_adapter = {
+ .owner = THIS_MODULE,
+ .name = "i2c-mlxcpld",
+ .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
+ .algo = &mlxcpld_i2c_algo,
+ .retries = MLXCPLD_I2C_RETR_NUM,
+ .nr = MLXCPLD_I2C_BUS_NUM,
+};
+
+static int mlxcpld_i2c_probe(struct platform_device *pdev)
+{
+ struct mlxcpld_i2c_priv *priv;
+ int err;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ mutex_init(&priv->lock);
+ platform_set_drvdata(pdev, priv);
+
+ priv->dev = &pdev->dev;
+
+ /* Register with i2c layer */
+ mlxcpld_i2c_adapter.timeout = usecs_to_jiffies(MLXCPLD_I2C_XFER_TO);
+ priv->adap = mlxcpld_i2c_adapter;
+ priv->adap.dev.parent = &pdev->dev;
+ priv->base_addr = MLXPLAT_CPLD_LPC_I2C_BASE_ADDR;
+ i2c_set_adapdata(&priv->adap, priv);
+
+ err = i2c_add_numbered_adapter(&priv->adap);
+ if (err)
+ mutex_destroy(&priv->lock);
+
+ return err;
+}
+
+static int mlxcpld_i2c_remove(struct platform_device *pdev)
+{
+ struct mlxcpld_i2c_priv *priv = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&priv->adap);
+ mutex_destroy(&priv->lock);
+
+ return 0;
+}
+
+static struct platform_driver mlxcpld_i2c_driver = {
+ .probe = mlxcpld_i2c_probe,
+ .remove = mlxcpld_i2c_remove,
+ .driver = {
+ .name = MLXCPLD_I2C_DEVICE_NAME,
+ },
+};
+
+module_platform_driver(mlxcpld_i2c_driver);
+
+MODULE_AUTHOR("Michael Shych <michaels@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox I2C-CPLD controller driver");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("platform:i2c-mlxcpld");
--
2.1.4
^ permalink raw reply related
* [Patch V5 1/2] i2c: imx: add devicetree binding for lpi2c
From: Gao Pan @ 2016-11-17 8:17 UTC (permalink / raw)
To: wsa, u.kleine-koenig, cmo, robh, vz
Cc: linux-i2c, pandy.gao, frank.li, fugang.duan
Add a binding document for lpi2c driver
Signed-off-by: Gao Pan <pandy.gao@nxp.com>
---
.../devicetree/bindings/i2c/i2c-imx-lpi2c.txt | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.txt b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.txt
new file mode 100644
index 0000000..70c054a
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.txt
@@ -0,0 +1,20 @@
+* Freescale Low Power Inter IC (LPI2C) for i.MX
+
+Required properties:
+- compatible :
+ - "fsl,imx7ulp-lpi2c" for LPI2C compatible with the one integrated on i.MX7ULP soc
+ - "fsl,imx8dv-lpi2c" for LPI2C compatible with the one integrated on i.MX8DV soc
+- reg : address and length of the lpi2c master registers
+- interrupt-parent : core interrupt controller
+- interrupts : lpi2c interrupt
+- clocks : lpi2c clock specifier
+
+Examples:
+
+lpi2c7: lpi2c7@40A50000 {
+ compatible = "fsl,imx8dv-lpi2c";
+ reg = <0x40A50000 0x10000>;
+ interrupt-parent = <&intc>;
+ interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
+ clocks = <&clks IMX7ULP_CLK_LPI2C7>;
+};
--
1.9.1
^ permalink raw reply related
* Re: [RFC PATCH 0/7] mux controller astraction and iio/i2c muxes
From: Peter Rosin @ 2016-11-17 9:33 UTC (permalink / raw)
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: Wolfram Sang, Rob Herring, Mark Rutland, Jonathan Cameron,
Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald-Stadler,
Arnd Bergmann, Greg Kroah-Hartman,
linux-i2c-u79uwXL29TY76Z2rM5mHXA,
devicetree-u79uwXL29TY76Z2rM5mHXA,
linux-iio-u79uwXL29TY76Z2rM5mHXA
In-Reply-To: <1479340111-1259-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
On 2016-11-17 00:48, Peter Rosin wrote:
> Hi!
>
> This is work in progress, I'm asking for early feedback.
Forgot to mention, sorry, but this series depends on some
stuff not in mainline yet (the _available work in iio [1]),
but it is in linux-next.
Cheers,
Peter
[1] Specifically these patches:
51239600074b "iio:core: add a callback to allow drivers to provide _available attributes"
00c5f80c2fad "iio: inkern: add helpers to query available values from channels"
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
^ permalink raw reply
* [patch v6 1/1] i2c: add master driver for mellanox systems
From: vadimp @ 2016-11-17 8:30 UTC (permalink / raw)
To: wsa; +Cc: linux-i2c, linux-kernel, jiri, Vadim Pasternak, Michael Shych
From: Vadim Pasternak <vadimp@mellanox.com>
Device driver for Mellanox I2C controller logic, implemented in Lattice
CPLD device.
Device supports:
- Master mode
- One physical bus
- Polling mode
The Kconfig currently controlling compilation of this code is:
drivers/i2c/busses/Kconfig:config I2C_MLXCPLD
Signed-off-by: Michael Shych <michaelsh@mellanox.com>
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
---
v5->v6:
Comments pointed out by Vladimir:
- Drop the line with module path from the header;
- In description of mlxcpld_i2c_priv remove lpc_gen_dec_reg asnd dev_id;
- In mlxcpld_i2c_priv change type of the filed base_addr to u16 for
the alignment with in/out and remove unused dev_id;
- Fix misspelling in comment for mlxcpld_i2c_invalid_len;
- Remove comment regarding EBUSY return in mlxcpld_i2c_check_busy;
- Use sizeof of the target storage in allocation in probe routine;
v4->v5:
Comments pointed out by Vladimir:
- Remove "default n" from Kconfig;
- Fix the comments for timeout and pool time;
- Optimize error flow in mlxcpld_i2c_probe;
v3->v4:
Comments pointed out by Vladimir:
- Set default to no in Kconfig;
- Make mlxcpld_i2c_plat_dev static and add empty line before the
declaration;
- In function mlxcpld_i2c_invalid_len remove (msg->len < 0), since len is
unsigned;
- Remove unused symbol mlxcpld_i2c_plat_dev;
- Remove extra spaces in comments to mlxcpld_i2c_check_msg_params;
- Remove unnecessary round braces in mlxcpld_i2c_set_transf_data;
- Remove the assignment of 'i' variable in mlxcpld_i2c_wait_for_tc;
- Add extra line in mlxcpld_i2c_xfer;
- Move assignment of the adapter's fields retries and nr inside
mlxcpld_i2c_adapter declaration;
v2->v3:
Comments pointed out by Vladimir:
- Use tab symbol as indentation in Kconfig
- Add the Kconfig section preserving the alphabetical order - added
within "Other I2C/SMBus bus drivers" after I2C_ELEKTOR (but after this
sections others are not follow alphabetical);
- Change license to dual;
- Replace ADRR with ADDR in macros;
- Remove unused macros: MLXCPLD_LPCI2C_LPF_DFLT,
MLXCPLD_LPCI2C_HALF_CYC_100, MLXCPLD_LPCI2C_I2C_HOLD_100,
MLXCPLD_LPCI2C_HALF_CYC_REG, MLXCPLD_LPCI2C_I2C_HOLD_REG;
- Fix checkpatch warnings (**/ and the end of comment);
- Add empty line before structures mlxcpld_i2c_regs,
mlxcpld_i2c_curr_transf, mlxcpld_i2c_priv;
- Remove unused structure mlxcpld_i2c_regs;
- Remove from mlxcpld_i2c_priv the next fields:
retr_num, poll_time, block_sz, xfer_to; use instead macros
respectively: MLXCPLD_I2C_RETR_NUM, MLXCPLD_I2C_POLL_TIME,
MLXCPLD_I2C_DATA_REG_SZ, MLXCPLD_I2C_XFER_TO;
- In mlxcpld_i2c_invalid_len remove unnecessary else;
- Optimize mlxcpld_i2c_set_transf_data;
- mlxcpld_i2c_reset - add empty lines after/before mutex
lock/unlock;
- mlxcpld_i2c_wait_for_free - cover case timeout is equal
MLXCPLD_I2C_XFER_TO;
- mlxcpld_i2c_wait_for_tc:
- Do not assign err in declaration (also err is removed);
- Insert empty line before case MLXCPLD_LPCI2C_ACK_IND;
- inside case MLXCPLD_LPCI2C_ACK_IND - avoid unnecessary
indentation;
- Remove case MLXCPLD_LPCI2C_ERR_IND and remove this macro;
- Add empty lines in mlxcpld_i2c_xfer before/after mutex_lock/
mutex_unlock;
- In mlxcpld_i2c_probe add emtpy line after platform_set_drvdata;
- Replace platfrom handle pdev in mlxcpld_i2c_priv with the pointer
to the structure device;
- Place assignment of base_addr near the others;
- Enclose e-mail with <>;
Fixes added by Vadim:
- Change structure description format according to
Documentation/kernel-documentation.rst guideline;
- mlxcpld_i2c_wait_for_tc: return error if status reaches default case;
v1->v2
Fixes added by Vadim:
- Put new record in Makefile in alphabetic order;
- Remove http://www.mellanox.com from MAINTAINERS record;
---
Documentation/i2c/busses/i2c-mlxcpld | 47 +++
MAINTAINERS | 8 +
drivers/i2c/busses/Kconfig | 11 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-mlxcpld.c | 544 +++++++++++++++++++++++++++++++++++
5 files changed, 611 insertions(+)
create mode 100644 Documentation/i2c/busses/i2c-mlxcpld
create mode 100644 drivers/i2c/busses/i2c-mlxcpld.c
diff --git a/Documentation/i2c/busses/i2c-mlxcpld b/Documentation/i2c/busses/i2c-mlxcpld
new file mode 100644
index 0000000..0f8678a
--- /dev/null
+++ b/Documentation/i2c/busses/i2c-mlxcpld
@@ -0,0 +1,47 @@
+Driver i2c-mlxcpld
+
+Author: Michael Shych <michaelsh@mellanox.com>
+
+This is a for Mellanox I2C controller logic, implemented in Lattice CPLD
+device.
+Device supports:
+ - Master mode.
+ - One physical bus.
+ - Polling mode.
+
+This controller is equipped within the next Mellanox systems:
+"msx6710", "msx6720", "msb7700", "msn2700", "msx1410", "msn2410", "msb7800",
+"msn2740", "msn2100".
+
+The next transaction types are supported:
+ - Receive Byte/Block.
+ - Send Byte/Block.
+ - Read Byte/Block.
+ - Write Byte/Block.
+
+Registers:
+CTRL 0x1 - control reg.
+ Resets all the registers.
+HALF_CYC 0x4 - cycle reg.
+ Configure the width of I2C SCL half clock cycle (in 4 LPC_CLK
+ units).
+I2C_HOLD 0x5 - hold reg.
+ OE (output enable) is delayed by value set to this register
+ (in LPC_CLK units)
+CMD 0x6 - command reg.
+ Bit 7(lsb), 0 = write, 1 = read.
+ Bits [6:0] - the 7bit Address of the I2C device.
+ It should be written last as it triggers an I2C transaction.
+NUM_DATA 0x7 - data size reg.
+ Number of address bytes to write in read transaction
+NUM_ADDR 0x8 - address reg.
+ Number of address bytes to write in read transaction.
+STATUS 0x9 - status reg.
+ Bit 0 - transaction is completed.
+ Bit 4 - ACK/NACK.
+DATAx 0xa - 0x54 - 68 bytes data buffer regs.
+ For write transaction address is specified in four first bytes
+ (DATA1 - DATA4), data starting from DATA4.
+ For read transactions address is send in separate transaction and
+ specified in four first bytes (DATA0 - DATA3). Data is reading
+ starting from DATA0.
diff --git a/MAINTAINERS b/MAINTAINERS
index 411e3b8..26d05f8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7881,6 +7881,14 @@ W: http://www.mellanox.com
Q: http://patchwork.ozlabs.org/project/netdev/list/
F: drivers/net/ethernet/mellanox/mlxsw/
+MELLANOX MLXCPLD I2C DRIVER
+M: Vadim Pasternak <vadimp@mellanox.com>
+M: Michael Shych <michaelsh@mellanox.com>
+L: linux-i2c@vger.kernel.org
+S: Supported
+F: drivers/i2c/busses/i2c-mlxcpld.c
+F: Documentation/i2c/busses/i2c-mlxcpld
+
MELLANOX MLXCPLD LED DRIVER
M: Vadim Pasternak <vadimp@mellanox.com>
L: linux-leds@vger.kernel.org
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index d252276..6399cea 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -1150,6 +1150,17 @@ config I2C_ELEKTOR
This support is also available as a module. If so, the module
will be called i2c-elektor.
+config I2C_MLXCPLD
+ tristate "Mellanox I2C driver"
+ depends on X86_64
+ help
+ This exposes the Mellanox platform I2C busses to the linux I2C layer
+ for X86 based systems.
+ Controller is implemented as CPLD logic.
+
+ This driver can also be built as a module. If so, the module will be
+ called as i2c-mlxcpld.
+
config I2C_PCA_ISA
tristate "PCA9564/PCA9665 on an ISA bus"
depends on ISA
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 29764cc..645bf08 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -116,6 +116,7 @@ obj-$(CONFIG_I2C_BCM_KONA) += i2c-bcm-kona.o
obj-$(CONFIG_I2C_BRCMSTB) += i2c-brcmstb.o
obj-$(CONFIG_I2C_CROS_EC_TUNNEL) += i2c-cros-ec-tunnel.o
obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o
+obj-$(CONFIG_I2C_MLXCPLD) += i2c-mlxcpld.o
obj-$(CONFIG_I2C_OPAL) += i2c-opal.o
obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o
obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o
diff --git a/drivers/i2c/busses/i2c-mlxcpld.c b/drivers/i2c/busses/i2c-mlxcpld.c
new file mode 100644
index 0000000..07d5657
--- /dev/null
+++ b/drivers/i2c/busses/i2c-mlxcpld.c
@@ -0,0 +1,544 @@
+/*
+ * Copyright (c) 2016 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2016 Michael Shych <michaels@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+/* General defines */
+#define MLXPLAT_CPLD_LPC_I2C_BASE_ADDR 0x2000
+#define MLXCPLD_I2C_DEVICE_NAME "i2c_mlxcpld"
+#define MLXCPLD_I2C_VALID_FLAG (I2C_M_RECV_LEN | I2C_M_RD)
+#define MLXCPLD_I2C_BUS_NUM 1
+#define MLXCPLD_I2C_DATA_REG_SZ 36
+#define MLXCPLD_I2C_MAX_ADDR_LEN 4
+#define MLXCPLD_I2C_RETR_NUM 2
+#define MLXCPLD_I2C_XFER_TO 500000 /* usec */
+#define MLXCPLD_I2C_POLL_TIME 2000 /* usec */
+
+/* LPC I2C registers */
+#define MLXCPLD_LPCI2C_LPF_REG 0x0
+#define MLXCPLD_LPCI2C_CTRL_REG 0x1
+#define MLXCPLD_LPCI2C_HALF_CYC_REG 0x4
+#define MLXCPLD_LPCI2C_I2C_HOLD_REG 0x5
+#define MLXCPLD_LPCI2C_CMD_REG 0x6
+#define MLXCPLD_LPCI2C_NUM_DAT_REG 0x7
+#define MLXCPLD_LPCI2C_NUM_ADDR_REG 0x8
+#define MLXCPLD_LPCI2C_STATUS_REG 0x9
+#define MLXCPLD_LPCI2C_DATA_REG 0xa
+
+/* LPC I2C masks and parametres */
+#define MLXCPLD_LPCI2C_RST_SEL_MASK 0x1
+#define MLXCPLD_LPCI2C_TRANS_END 0x1
+#define MLXCPLD_LPCI2C_STATUS_NACK 0x10
+#define MLXCPLD_LPCI2C_NO_IND 0
+#define MLXCPLD_LPCI2C_ACK_IND 1
+#define MLXCPLD_LPCI2C_NACK_IND 2
+
+/**
+ * struct mlxcpld_i2c_curr_transf - current transaction parameters:
+ * @cmd: command;
+ * @addr_width: address width;
+ * @data_len: data length;
+ * @cmd: command register;
+ * @msg_num: message number;
+ * @msg: pointer to message buffer;
+ */
+
+struct mlxcpld_i2c_curr_transf {
+ u8 cmd;
+ u8 addr_width;
+ u8 data_len;
+ u8 msg_num;
+ struct i2c_msg *msg;
+};
+
+/**
+ * struct mlxcpld_i2c_priv - private controller data:
+ * @adap: i2c adapter;
+ * @base_addr: base IO address;
+ * @lock: bus access lock;
+ * @xfer: current i2c transfer block;
+ * @dev: device handle;
+ */
+
+struct mlxcpld_i2c_priv {
+ struct i2c_adapter adap;
+ u32 base_addr;
+ struct mutex lock;
+ struct mlxcpld_i2c_curr_transf xfer;
+ struct device *dev;
+};
+
+static void mlxcpld_i2c_lpc_write_buf(u8 *data, u8 len, u32 addr)
+{
+ int i, nbyte, ndword;
+
+ nbyte = len % 4;
+ ndword = len / 4;
+ for (i = 0; i < ndword; i++)
+ outl(*((u32 *)data + i), addr + i * 4);
+ ndword *= 4;
+ addr += ndword;
+ data += ndword;
+ for (i = 0; i < nbyte; i++)
+ outb(*(data + i), addr + i);
+}
+
+static void mlxcpld_i2c_lpc_read_buf(u8 *data, u8 len, u32 addr)
+{
+ int i, nbyte, ndword;
+
+ nbyte = len % 4;
+ ndword = len / 4;
+ for (i = 0; i < ndword; i++)
+ *((u32 *)data + i) = inl(addr + i * 4);
+ ndword *= 4;
+ addr += ndword;
+ data += ndword;
+ for (i = 0; i < nbyte; i++)
+ *(data + i) = inb(addr + i);
+}
+
+static void mlxcpld_i2c_read_comm(struct mlxcpld_i2c_priv *priv, u8 offs,
+ u8 *data, u8 datalen)
+{
+ u32 addr = priv->base_addr + offs;
+
+ switch (datalen) {
+ case 1:
+ *(data) = inb(addr);
+ break;
+ case 2:
+ *((u16 *)data) = inw(addr);
+ break;
+ case 3:
+ *((u16 *)data) = inw(addr);
+ *(data + 2) = inb(addr + 2);
+ break;
+ case 4:
+ *((u32 *)data) = inl(addr);
+ break;
+ default:
+ mlxcpld_i2c_lpc_read_buf(data, datalen, addr);
+ break;
+ }
+}
+
+static void mlxcpld_i2c_write_comm(struct mlxcpld_i2c_priv *priv, u8 offs,
+ u8 *data, u8 datalen)
+{
+ u32 addr = priv->base_addr + offs;
+
+ switch (datalen) {
+ case 1:
+ outb(*(data), addr);
+ break;
+ case 2:
+ outw(*((u16 *)data), addr);
+ break;
+ case 3:
+ outw(*((u16 *)data), addr);
+ outb(*(data + 2), addr + 2);
+ break;
+ case 4:
+ outl(*((u32 *)data), addr);
+ break;
+ default:
+ mlxcpld_i2c_lpc_write_buf(data, datalen, addr);
+ break;
+ }
+}
+
+/* Check validity of current i2c message and all transfer.
+ * Calculate also common length of all i2c messages in transfer.
+ */
+static int mlxcpld_i2c_invalid_len(struct mlxcpld_i2c_priv *priv,
+ const struct i2c_msg *msg, u8 *comm_len)
+{
+ u8 max_len = msg->flags == I2C_M_RD ? MLXCPLD_I2C_DATA_REG_SZ -
+ MLXCPLD_I2C_MAX_ADDR_LEN : MLXCPLD_I2C_DATA_REG_SZ;
+
+ if (msg->len > max_len)
+ return -EINVAL;
+
+ *comm_len += msg->len;
+ if (*comm_len > MLXCPLD_I2C_DATA_REG_SZ)
+ return -EINVAL;
+
+ return 0;
+}
+
+/* Check validity of received i2c messages parameters.
+ * Returns 0 if OK, other - in case of invalid parameters
+ * or common length of data that should be passed to CPLD
+ */
+static int mlxcpld_i2c_check_msg_params(struct mlxcpld_i2c_priv *priv,
+ struct i2c_msg *msgs, int num,
+ u8 *comm_len)
+{
+ int i;
+
+ if (!num) {
+ dev_err(priv->dev, "Incorrect 0 num of messages\n");
+ return -EINVAL;
+ }
+
+ if (unlikely(msgs[0].addr > 0x7f)) {
+ dev_err(priv->dev, "Invalid address 0x%03x\n",
+ msgs[0].addr);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < num; ++i) {
+ if (unlikely(!msgs[i].buf)) {
+ dev_err(priv->dev, "Invalid buf in msg[%d]\n",
+ i);
+ return -EINVAL;
+ }
+ if (unlikely(msgs[0].addr != msgs[i].addr)) {
+ dev_err(priv->dev, "Invalid addr in msg[%d]\n",
+ i);
+ return -EINVAL;
+ }
+ if (unlikely(mlxcpld_i2c_invalid_len(priv, &msgs[i],
+ comm_len))) {
+ dev_err(priv->dev, "Invalid len %d msg[%d], addr 0x%x, lag %u\n",
+ msgs[i].len, i, msgs[i].addr, msgs[i].flags);
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/* Check if transfer is completed and status of operation.
+ * Returns 0 - transfer completed (both ACK or NACK),
+ * negative - transfer isn't finished.
+ */
+static int mlxcpld_i2c_check_status(struct mlxcpld_i2c_priv *priv, int *status)
+{
+ u8 val;
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_STATUS_REG, &val, 1);
+
+ if (val & MLXCPLD_LPCI2C_TRANS_END) {
+ if (val & MLXCPLD_LPCI2C_STATUS_NACK)
+ /* The slave is unable to accept the data. No such
+ * slave, command not understood, or unable to accept
+ * any more data.
+ */
+ *status = MLXCPLD_LPCI2C_NACK_IND;
+ else
+ *status = MLXCPLD_LPCI2C_ACK_IND;
+ return 0;
+ }
+ *status = MLXCPLD_LPCI2C_NO_IND;
+
+ return -EIO;
+}
+
+static void mlxcpld_i2c_set_transf_data(struct mlxcpld_i2c_priv *priv,
+ struct i2c_msg *msgs, int num,
+ u8 comm_len)
+{
+ priv->xfer.msg = msgs;
+ priv->xfer.msg_num = num;
+
+ /*
+ * All upper layers currently are never use transfer with more than
+ * 2 messages. Actually, it's also not so relevant in Mellanox systems
+ * because of HW limitation. Max size of transfer is o more than 20B
+ * in current x86 LPCI2C bridge.
+ */
+ priv->xfer.cmd = msgs[num - 1].flags & I2C_M_RD;
+
+ if (priv->xfer.cmd == I2C_M_RD && comm_len != msgs[0].len) {
+ priv->xfer.addr_width = msgs[0].len;
+ priv->xfer.data_len = comm_len - priv->xfer.addr_width;
+ } else {
+ priv->xfer.addr_width = 0;
+ priv->xfer.data_len = comm_len;
+ }
+}
+
+/* Reset CPLD LPCI2C block */
+static void mlxcpld_i2c_reset(struct mlxcpld_i2c_priv *priv)
+{
+ u8 val;
+
+ mutex_lock(&priv->lock);
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_CTRL_REG, &val, 1);
+ val &= ~MLXCPLD_LPCI2C_RST_SEL_MASK;
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_CTRL_REG, &val, 1);
+
+ mutex_unlock(&priv->lock);
+}
+
+/* Make sure the CPLD is ready to start transmitting. */
+static int mlxcpld_i2c_check_busy(struct mlxcpld_i2c_priv *priv)
+{
+ u8 val;
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_STATUS_REG, &val, 1);
+
+ if (val & MLXCPLD_LPCI2C_TRANS_END)
+ return 0;
+
+ return -EIO;
+}
+
+static int mlxcpld_i2c_wait_for_free(struct mlxcpld_i2c_priv *priv)
+{
+ int timeout = 0;
+
+ do {
+ if (!mlxcpld_i2c_check_busy(priv))
+ break;
+ usleep_range(MLXCPLD_I2C_POLL_TIME / 2, MLXCPLD_I2C_POLL_TIME);
+ timeout += MLXCPLD_I2C_POLL_TIME;
+ } while (timeout <= MLXCPLD_I2C_XFER_TO);
+
+ if (timeout > MLXCPLD_I2C_XFER_TO)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+/*
+ * Wait for master transfer to complete.
+ * It puts current process to sleep until we get interrupt or timeout expires.
+ * Returns the number of transferred or read bytes or error (<0).
+ */
+static int mlxcpld_i2c_wait_for_tc(struct mlxcpld_i2c_priv *priv)
+{
+ int status, i, timeout = 0;
+ u8 datalen;
+
+ do {
+ usleep_range(MLXCPLD_I2C_POLL_TIME / 2, MLXCPLD_I2C_POLL_TIME);
+ if (!mlxcpld_i2c_check_status(priv, &status))
+ break;
+ timeout += MLXCPLD_I2C_POLL_TIME;
+ } while (status == 0 && timeout < MLXCPLD_I2C_XFER_TO);
+
+ switch (status) {
+ case MLXCPLD_LPCI2C_NO_IND:
+ return -ETIMEDOUT;
+
+ case MLXCPLD_LPCI2C_ACK_IND:
+ if (priv->xfer.cmd != I2C_M_RD)
+ return (priv->xfer.addr_width + priv->xfer.data_len);
+
+ if (priv->xfer.msg_num == 1)
+ i = 0;
+ else
+ i = 1;
+
+ if (!priv->xfer.msg[i].buf)
+ return -EINVAL;
+
+ /*
+ * Actual read data len will be always the same as
+ * requested len. 0xff (line pull-up) will be returned
+ * if slave has no data to return. Thus don't read
+ * MLXCPLD_LPCI2C_NUM_DAT_REG reg from CPLD.
+ */
+ datalen = priv->xfer.data_len;
+
+ mlxcpld_i2c_read_comm(priv, MLXCPLD_LPCI2C_DATA_REG,
+ priv->xfer.msg[i].buf, datalen);
+
+ return datalen;
+
+ case MLXCPLD_LPCI2C_NACK_IND:
+ return -EAGAIN;
+
+ default:
+ return -EINVAL;
+ }
+}
+
+static void mlxcpld_i2c_xfer_msg(struct mlxcpld_i2c_priv *priv)
+{
+ int i, len = 0;
+ u8 cmd;
+
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_DAT_REG,
+ &priv->xfer.data_len, 1);
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_NUM_ADDR_REG,
+ &priv->xfer.addr_width, 1);
+
+ for (i = 0; i < priv->xfer.msg_num; i++) {
+ if ((priv->xfer.msg[i].flags & I2C_M_RD) != I2C_M_RD) {
+ /* Don't write to CPLD buffer in read transaction */
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_DATA_REG +
+ len, priv->xfer.msg[i].buf,
+ priv->xfer.msg[i].len);
+ len += priv->xfer.msg[i].len;
+ }
+ }
+
+ /* Set target slave address with command for master transfer.
+ * It should be latest executed function before CPLD transaction.
+ */
+ cmd = (priv->xfer.msg[0].addr << 1) | priv->xfer.cmd;
+ mlxcpld_i2c_write_comm(priv, MLXCPLD_LPCI2C_CMD_REG, &cmd, 1);
+}
+
+/* Generic lpc-i2c transfer.
+ * Returns the number of processed messages or error (<0).
+ */
+static int mlxcpld_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct mlxcpld_i2c_priv *priv = i2c_get_adapdata(adap);
+ u8 comm_len = 0;
+ int err;
+
+ err = mlxcpld_i2c_check_msg_params(priv, msgs, num, &comm_len);
+ if (err) {
+ dev_err(priv->dev, "Incorrect message\n");
+ return err;
+ }
+
+ /* Check bus state */
+ if (mlxcpld_i2c_wait_for_free(priv)) {
+ dev_err(priv->dev, "LPCI2C bridge is busy\n");
+
+ /*
+ * Usually it means something serious has happened.
+ * We can not have unfinished previous transfer
+ * so it doesn't make any sense to try to stop it.
+ * Probably we were not able to recover from the
+ * previous error.
+ * The only reasonable thing - is soft reset.
+ */
+ mlxcpld_i2c_reset(priv);
+ if (mlxcpld_i2c_check_busy(priv)) {
+ dev_err(priv->dev, "LPCI2C bridge is busy after reset\n");
+ return -EIO;
+ }
+ }
+
+ mlxcpld_i2c_set_transf_data(priv, msgs, num, comm_len);
+
+ mutex_lock(&priv->lock);
+
+ /* Do real transfer. Can't fail */
+ mlxcpld_i2c_xfer_msg(priv);
+
+ /* Wait for transaction complete */
+ err = mlxcpld_i2c_wait_for_tc(priv);
+
+ mutex_unlock(&priv->lock);
+
+ return err < 0 ? err : num;
+}
+
+static u32 mlxcpld_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm mlxcpld_i2c_algo = {
+ .master_xfer = mlxcpld_i2c_xfer,
+ .functionality = mlxcpld_i2c_func
+};
+
+static struct i2c_adapter mlxcpld_i2c_adapter = {
+ .owner = THIS_MODULE,
+ .name = "i2c-mlxcpld",
+ .class = I2C_CLASS_HWMON | I2C_CLASS_SPD,
+ .algo = &mlxcpld_i2c_algo,
+ .retries = MLXCPLD_I2C_RETR_NUM,
+ .nr = MLXCPLD_I2C_BUS_NUM,
+};
+
+static int mlxcpld_i2c_probe(struct platform_device *pdev)
+{
+ struct mlxcpld_i2c_priv *priv;
+ int err;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ mutex_init(&priv->lock);
+ platform_set_drvdata(pdev, priv);
+
+ priv->dev = &pdev->dev;
+
+ /* Register with i2c layer */
+ mlxcpld_i2c_adapter.timeout = usecs_to_jiffies(MLXCPLD_I2C_XFER_TO);
+ priv->adap = mlxcpld_i2c_adapter;
+ priv->adap.dev.parent = &pdev->dev;
+ priv->base_addr = MLXPLAT_CPLD_LPC_I2C_BASE_ADDR;
+ i2c_set_adapdata(&priv->adap, priv);
+
+ err = i2c_add_numbered_adapter(&priv->adap);
+ if (err)
+ mutex_destroy(&priv->lock);
+
+ return err;
+}
+
+static int mlxcpld_i2c_remove(struct platform_device *pdev)
+{
+ struct mlxcpld_i2c_priv *priv = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&priv->adap);
+ mutex_destroy(&priv->lock);
+
+ return 0;
+}
+
+static struct platform_driver mlxcpld_i2c_driver = {
+ .probe = mlxcpld_i2c_probe,
+ .remove = mlxcpld_i2c_remove,
+ .driver = {
+ .name = MLXCPLD_I2C_DEVICE_NAME,
+ },
+};
+
+module_platform_driver(mlxcpld_i2c_driver);
+
+MODULE_AUTHOR("Michael Shych <michaels@mellanox.com>");
+MODULE_DESCRIPTION("Mellanox I2C-CPLD controller driver");
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_ALIAS("platform:i2c-mlxcpld");
--
2.1.4
^ permalink raw reply related
* RE: [Patch V4 2/2] i2c: imx: add devicetree binding for lpi2c
From: Pandy Gao @ 2016-11-17 6:52 UTC (permalink / raw)
To: Vladimir Zapolskiy, wsa@the-dreams.de,
u.kleine-koenig@pengutronix.de, cmo@melexis.com, robh@kernel.org
Cc: linux-i2c@vger.kernel.org, Frank Li, Andy Duan
In-Reply-To: <19931d8c-08eb-5dd8-795f-20e900e4be4f@mleia.com>
From: Vladimir Zapolskiy <mailto:vz@mleia.com> Sent: Thursday, November 17, 2016 8:32 AM
> To: Pandy Gao <pandy.gao@nxp.com>; wsa@the-dreams.de; u.kleine-
> koenig@pengutronix.de; cmo@melexis.com; robh@kernel.org
> Cc: linux-i2c@vger.kernel.org; Frank Li <frank.li@nxp.com>; Andy Duan
> <fugang.duan@nxp.com>
> Subject: Re: [Patch V4 2/2] i2c: imx: add devicetree binding for lpi2c
>
> On 11/14/2016 11:23 AM, Gao Pan wrote:
> > Add a binding document for lpi2c driver
> >
> > Signed-off-by: Gao Pan <pandy.gao@nxp.com>
> > ---
> > .../devicetree/bindings/i2c/i2c-imx-lpi2c.txt | 20
> ++++++++++++++++++++
> > 1 file changed, 20 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.txt
> > b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.txt
> > new file mode 100644
> > index 0000000..edaf04f
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/i2c/i2c-imx-lpi2c.txt
> > @@ -0,0 +1,20 @@
> > +* Freescale Low Power Inter IC (LPI2C) for i.MX
> > +
> > +Required properties:
> > +- compatible :
> > + - "fsl,imx8dv-lpi2c" for LPI2C compatible with the one integrated
> > +on i.MX8DV soc
> > + - "fsl,imx7ulp-lpi2c" for LPI2C compatible with the one integrated
> > +on i.MX7ULP soc
> > +- reg : address and length of the lpi2c master registers
> > +- interrupt-parent : core interrupt controller
> > +- interrupts : lpi2c interrupt
> > +- clocks : lpi2c clock specifier
>
> I don't know if description of standard properties is really needed, probably
> Rob can advise.
>
> My point is that pretty "interrupts-extended" is never mentioned, and all three
> interrupt* properties are well described in interrupts.txt, and in general there is
> no point to mention all those interrupts, clocks, clock-names and friends
> properties again and again.
>
> But here better to get a clarification from Rob.
Thanks.
> > +
> > +Examples:
> > +
> > +lpi2c7: lpi2c7@40A50000 {
> > + compatible = "fsl,imx8dv-lpi2c";
> > + reg = <0x40A50000 0x10000>;
> > + interrupt-parent = <&intc>;
> > + interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
> > + clocks = <&clks IMX7ULP_CLK_LPI2C7>; };
> >
>
> Please rearrange the changes, devicetree binding change should be 1/2, the
> driver change should be 2/2.
Thanks, will change it in next version.
Best Regards
Gao Pan
^ permalink raw reply
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