[PATCH linux-next v10 0/3] mfd: flexcom: add a driver for Flexcom

[PATCH linux-next v10 0/3] mfd: flexcom: add a driver for Flexcom

[Cyrille Pitchen]

This series of patches a support to the Atmel Flexcom, a wrapper which
integrates an USART, a SPI controller and a TWI controller. Only one
peripheral can be used at a time. The active function is selected though
the Flexcom Mode Register


ChangeLog

v10:
- add Acked-by from Nicolas Ferre

v9:
- go back to v5 (use the new "atmel,flexcom-mode" DT property).
- fix the name of the spi node in the DT example: from spi@f8034400 to
  spi@400
- align the fields of the struct platform_driver atmel_flexcom_driver as
  suggested by Lee Jones.

v8:
- fix the name of the spi node in the DT example: from spi@f8034400 to
  spi@2,0
- use the return code of op_property_read_u32_index() instead of -EINVAL
  to report error.
- add Acked-by from Nicolas Ferre

v7:
- read the operating mode from the very first u32 of the reg property from
  the first available child node (should be unique).
- update the DT bindings documentation accordingly.

v6:
- select the operating mode according to the "compatible" DT property of
  the first available child node (should be unique).
- remove the "atmel,flexcom-mode" DT property so the need of a header file
  defining macros for the possible values of this deprecated property.

v5:
- create a header file containing macros used by DT bindings
- use numeric constants instead of strings to select the Flexcom mode
- change the license to "GPL v2"
- update the DT binding documentation to make it more readable and add
  references to USART, SPI and I2C DT binding documentations. remove the
  useless label in the Example section.
- change the register prefix from FX_ to FLEX_ to match the Flexcom
  programmer datasheet.
- rename some variables to make them more understandable.

v4:
- check clk_prepare_enable() return code in atmel_flexcom_probe()
- add a commit message to the DT binding patch

v3:
- remove MODULE_ALIAS()
- add Acked-by from Boris Brezillon and Alexandre Belloni

v2:
- enhance the documentation of DT bindings and change the way the "ranges"
  property is used.
- replace __raw_readl() and __raw_writel() by readl() and writel().
- change the module license to "GPL" for v2 or later
- print the selected flexcom mode after the hardware version

Cyrille Pitchen (3):
  mfd: atmel-flexcom: create include file with macros used by DT
    bindings
  mfd: devicetree: add bindings for Atmel Flexcom
  mfd: atmel-flexcom: add a driver for Atmel Flexible Serial
    Communication Unit

 .../devicetree/bindings/mfd/atmel-flexcom.txt      |  67 +++++++++++++
 drivers/mfd/Kconfig                                |  11 +++
 drivers/mfd/Makefile                               |   1 +
 drivers/mfd/atmel-flexcom.c                        | 104 +++++++++++++++++++++
 include/dt-bindings/mfd/atmel-flexcom.h            |  16 ++++
 5 files changed, 199 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
 create mode 100644 drivers/mfd/atmel-flexcom.c
 create mode 100644 include/dt-bindings/mfd/atmel-flexcom.h

-- 
1.8.2.2

[PATCH linux-next v10 1/3] mfd: atmel-flexcom: create include file with macros used by DT bindings

[Cyrille Pitchen]

This patch defines some macros to be used as value for the
"atmel,flexcom-mode" DT property. This value is then written into
the Operating Mode (OPMODE) bit field of the Flexcom Mode Register.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
Acked-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
 include/dt-bindings/mfd/atmel-flexcom.h | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 include/dt-bindings/mfd/atmel-flexcom.h

diff --git a/include/dt-bindings/mfd/atmel-flexcom.h b/include/dt-bindings/mfd/atmel-flexcom.h
new file mode 100644
index 000000000000..6728f2851b4d
--- /dev/null
+++ b/include/dt-bindings/mfd/atmel-flexcom.h
@@ -0,0 +1,16 @@
+/*
+ * This header provides macros for Atmel Flexcom DT bindings.
+ *
+ * Copyright (C) 2015 Cyrille Pitchen <cyrille.pitchen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
+ *
+ * GPLv2 only
+ */
+
+#ifndef __DT_BINDINGS_ATMEL_FLEXCOM_H__
+#define __DT_BINDINGS_ATMEL_FLEXCOM_H__
+
+#define ATMEL_FLEXCOM_MODE_USART	1
+#define ATMEL_FLEXCOM_MODE_SPI		2
+#define ATMEL_FLEXCOM_MODE_TWI		3
+
+#endif /* __DT_BINDINGS_ATMEL_FLEXCOM_H__ */
-- 
1.8.2.2

--
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

Re: [PATCH linux-next v10 1/3] mfd: atmel-flexcom: create include file with macros used by DT bindings

[Lee Jones]

On Thu, 24 Sep 2015, Cyrille Pitchen wrote:

> This patch defines some macros to be used as value for the
> "atmel,flexcom-mode" DT property. This value is then written into
> the Operating Mode (OPMODE) bit field of the Flexcom Mode Register.
> 
> Signed-off-by: Cyrille Pitchen <cyrille.pitchen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> Acked-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> ---
>  include/dt-bindings/mfd/atmel-flexcom.h | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
>  create mode 100644 include/dt-bindings/mfd/atmel-flexcom.h
> 
> diff --git a/include/dt-bindings/mfd/atmel-flexcom.h b/include/dt-bindings/mfd/atmel-flexcom.h
> new file mode 100644
> index 000000000000..6728f2851b4d
> --- /dev/null
> +++ b/include/dt-bindings/mfd/atmel-flexcom.h
> @@ -0,0 +1,16 @@
> +/*
> + * This header provides macros for Atmel Flexcom DT bindings.
> + *
> + * Copyright (C) 2015 Cyrille Pitchen <cyrille.pitchen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
> + *
> + * GPLv2 only

I'm not sure this constitutes as a proper licence statement.

> + */
> +
> +#ifndef __DT_BINDINGS_ATMEL_FLEXCOM_H__
> +#define __DT_BINDINGS_ATMEL_FLEXCOM_H__
> +
> +#define ATMEL_FLEXCOM_MODE_USART	1
> +#define ATMEL_FLEXCOM_MODE_SPI		2
> +#define ATMEL_FLEXCOM_MODE_TWI		3
> +
> +#endif /* __DT_BINDINGS_ATMEL_FLEXCOM_H__ */

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog
--
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

[PATCH linux-next v10 2/3] mfd: devicetree: add bindings for Atmel Flexcom

[Cyrille Pitchen]

This patch documents the DT bindings for the Atmel Flexcom which will be
introduced by sama5d2x SoCs. These bindings will be used by the actual
Flexcom driver to be sent in another patch.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
Acked-by: Boris Brezillon <boris.brezillon-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Acked-by: Alexandre Belloni <alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org>
Acked-by: Nicolas Ferre <nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org>
---
 .../devicetree/bindings/mfd/atmel-flexcom.txt      | 67 ++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mfd/atmel-flexcom.txt

diff --git a/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
new file mode 100644
index 000000000000..fc3511e41542
--- /dev/null
+++ b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
@@ -0,0 +1,67 @@
+* Device tree bindings for Atmel Flexcom (Flexible Serial Communication Unit)
+
+The Atmel Flexcom is just a wrapper which embeds a SPI controller, an I2C
+controller and an USART. Only one function can be used at a time and is chosen
+at boot time according to the device tree.
+
+Required properties:
+- compatible:		Should be "atmel,sama5d2-flexcom"
+- reg:			Should be the offset/length value for Flexcom dedicated
+			I/O registers (without USART, TWI or SPI registers).
+- clocks:		Should be the Flexcom peripheral clock from PMC.
+- #address-cells:	Should be <1>
+- #size-cells:		Should be <1>
+- ranges:		Should be one range for the full I/O register region
+			(including USART, TWI and SPI registers).
+- atmel,flexcom-mode:	Should be one of the 3 following macros as defined in
+			include/dt-bindings/mfd/atmel-flexcom.h:
+			- ATMEL_FLEXCOM_MODE_USART for USART
+			- ATMEL_FLEXCOM_MODE_SPI for SPI
+			- ATMEL_FLEXCOM_MODE_TWI for I2C
+
+Required child:
+a single child device of type matching the "atmel,flexcom-mode" property.
+
+The reg property of this child should be:
+- <0x200 0x200> for USART
+- <0x400 0x200> for SPI
+- <0x600 0x200> for I2C
+
+The phandle provided by the clocks property of the child is the same as one for
+the Flexcom parent.
+
+Other properties remain unchanged. See documentation of the respective device:
+- ../serial/atmel-usart.txt
+- ../spi/spi_atmel.txt
+- ../i2c/i2c-at91.txt
+
+Example:
+
+flexcom@f8034000 {
+	compatible = "atmel,sama5d2-flexcom";
+	reg = <0xf8034000 0x200>;
+	clocks = <&flx0_clk>;
+	#address-cells = <1>;
+	#size-cells = <1>;
+	ranges = <0x0 0xf8034000 0x800>;
+	atmel,flexcom-mode = <ATMEL_FLEXCOM_MODE_SPI>;
+
+	spi@400 {
+		compatible = "atmel,at91rm9200-spi";
+		reg = <0x400 0x200>;
+		interrupts = <19 IRQ_TYPE_LEVEL_HIGH 7>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&pinctrl_flx0_default>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		clocks = <&flx0_clk>;
+		clock-names = "spi_clk";
+		atmel,fifo-size = <32>;
+
+		mtd_dataflash@0 {
+			compatible = "atmel,at25f512b";
+			reg = <0>;
+			spi-max-frequency = <20000000>;
+		};
+	};
+};
-- 
1.8.2.2

--
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

Re: [PATCH linux-next v10 2/3] mfd: devicetree: add bindings for Atmel Flexcom

[Lee Jones]

On Thu, 24 Sep 2015, Cyrille Pitchen wrote:

> This patch documents the DT bindings for the Atmel Flexcom which will be
> introduced by sama5d2x SoCs. These bindings will be used by the actual
> Flexcom driver to be sent in another patch.
> 
> Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
> ---
>  .../devicetree/bindings/mfd/atmel-flexcom.txt      | 67 ++++++++++++++++++++++
>  1 file changed, 67 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
> 
> diff --git a/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
> new file mode 100644
> index 000000000000..fc3511e41542
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/atmel-flexcom.txt
> @@ -0,0 +1,67 @@
> +* Device tree bindings for Atmel Flexcom (Flexible Serial Communication Unit)
> +
> +The Atmel Flexcom is just a wrapper which embeds a SPI controller, an I2C
> +controller and an USART. Only one function can be used at a time and is chosen
> +at boot time according to the device tree.
> +
> +Required properties:
> +- compatible:		Should be "atmel,sama5d2-flexcom"
> +- reg:			Should be the offset/length value for Flexcom dedicated
> +			I/O registers (without USART, TWI or SPI registers).
> +- clocks:		Should be the Flexcom peripheral clock from PMC.
> +- #address-cells:	Should be <1>
> +- #size-cells:		Should be <1>
> +- ranges:		Should be one range for the full I/O register region
> +			(including USART, TWI and SPI registers).
> +- atmel,flexcom-mode:	Should be one of the 3 following macros as defined in

They're not macros.

> +			include/dt-bindings/mfd/atmel-flexcom.h:

This is Linux specific.  Please remove it from the binding document.

> +			- ATMEL_FLEXCOM_MODE_USART for USART
> +			- ATMEL_FLEXCOM_MODE_SPI for SPI
> +			- ATMEL_FLEXCOM_MODE_TWI for I2C
> +
> +Required child:
> +a single child device of type matching the "atmel,flexcom-mode" property.

s/a/A/

> +The reg property of this child should be:
> +- <0x200 0x200> for USART
> +- <0x400 0x200> for SPI
> +- <0x600 0x200> for I2C

Address/offset information doesn't belong in the binding document.

> +The phandle provided by the clocks property of the child is the same as one for
> +the Flexcom parent.
> +
> +Other properties remain unchanged. See documentation of the respective device:

Unchanged since when?

> +- ../serial/atmel-usart.txt
> +- ../spi/spi_atmel.txt
> +- ../i2c/i2c-at91.txt
> +
> +Example:
> +
> +flexcom@f8034000 {
> +	compatible = "atmel,sama5d2-flexcom";
> +	reg = <0xf8034000 0x200>;
> +	clocks = <&flx0_clk>;
> +	#address-cells = <1>;
> +	#size-cells = <1>;
> +	ranges = <0x0 0xf8034000 0x800>;
> +	atmel,flexcom-mode = <ATMEL_FLEXCOM_MODE_SPI>;
> +
> +	spi@400 {
> +		compatible = "atmel,at91rm9200-spi";
> +		reg = <0x400 0x200>;
> +		interrupts = <19 IRQ_TYPE_LEVEL_HIGH 7>;
> +		pinctrl-names = "default";
> +		pinctrl-0 = <&pinctrl_flx0_default>;
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		clocks = <&flx0_clk>;
> +		clock-names = "spi_clk";
> +		atmel,fifo-size = <32>;
> +
> +		mtd_dataflash@0 {
> +			compatible = "atmel,at25f512b";
> +			reg = <0>;
> +			spi-max-frequency = <20000000>;
> +		};
> +	};
> +};

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
Linaro.org │ Open source software for ARM SoCs
Follow Linaro: Facebook | Twitter | Blog

[PATCH linux-next v10 3/3] mfd: atmel-flexcom: add a driver for Atmel Flexible Serial Communication Unit

[Cyrille Pitchen]

This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which
integrates one SPI controller, one I2C controller and one USART. Only one
function can be enabled at a time. This driver selects the function once
for all, when the Flexcom is probed, according to the value of the new
"atmel,flexcom-mode" device tree property.

This driver has chosen to present the Flexcom to the system as a MFD so
the implementation is seamless for the existing Atmel SPI, I2C and USART
drivers.

Also the Flexcom embeds FIFOs: the latest patches of the SPI, I2C and
USART drivers take advantage of this new feature.

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
---
 drivers/mfd/Kconfig         |  11 +++++
 drivers/mfd/Makefile        |   1 +
 drivers/mfd/atmel-flexcom.c | 104 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 116 insertions(+)
 create mode 100644 drivers/mfd/atmel-flexcom.c

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 99d63675f073..87e84e7c71da 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -60,6 +60,17 @@ config MFD_AAT2870_CORE
 	  additional drivers must be enabled in order to use the
 	  functionality of the device.
 
+config MFD_ATMEL_FLEXCOM
+	tristate "Atmel Flexcom (Flexible Serial Communication Unit)"
+	select MFD_CORE
+	depends on OF
+	help
+	  Select this to get support for Atmel Flexcom. This is a wrapper
+	  which embeds a SPI controller, a I2C controller and a USART. Only
+	  one function can be used at a time. The choice is done at boot time
+	  by the probe function of this MFD driver according to a device tree
+	  property.
+
 config MFD_ATMEL_HLCDC
 	tristate "Atmel HLCDC (High-end LCD Controller)"
 	select MFD_CORE
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index d6c21e3c409f..a8b76b81b467 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -164,6 +164,7 @@ obj-$(CONFIG_MFD_SPMI_PMIC)	+= qcom-spmi-pmic.o
 obj-$(CONFIG_TPS65911_COMPARATOR)	+= tps65911-comparator.o
 obj-$(CONFIG_MFD_TPS65090)	+= tps65090.o
 obj-$(CONFIG_MFD_AAT2870_CORE)	+= aat2870-core.o
+obj-$(CONFIG_MFD_ATMEL_FLEXCOM)	+= atmel-flexcom.o
 obj-$(CONFIG_MFD_ATMEL_HLCDC)	+= atmel-hlcdc.o
 obj-$(CONFIG_MFD_INTEL_LPSS)	+= intel-lpss.o
 obj-$(CONFIG_MFD_INTEL_LPSS_PCI)	+= intel-lpss-pci.o
diff --git a/drivers/mfd/atmel-flexcom.c b/drivers/mfd/atmel-flexcom.c
new file mode 100644
index 000000000000..e8e67be6b493
--- /dev/null
+++ b/drivers/mfd/atmel-flexcom.c
@@ -0,0 +1,104 @@
+/*
+ * Driver for Atmel Flexcom
+ *
+ * Copyright (C) 2015 Atmel Corporation
+ *
+ * Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <dt-bindings/mfd/atmel-flexcom.h>
+
+/* I/O register offsets */
+#define FLEX_MR		0x0	/* Mode Register */
+#define FLEX_VERSION	0xfc	/* Version Register */
+
+/* Mode Register bit fields */
+#define FLEX_MR_OPMODE_OFFSET	(0)  /* Operating Mode */
+#define FLEX_MR_OPMODE_MASK	(0x3 << FLEX_MR_OPMODE_OFFSET)
+#define FLEX_MR_OPMODE(opmode)	(((opmode) << FLEX_MR_OPMODE_OFFSET) &	\
+				 FLEX_MR_OPMODE_MASK)
+
+
+static int atmel_flexcom_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct clk *clk;
+	struct resource *res;
+	void __iomem *base;
+	u32 opmode;
+	int err;
+
+	err = of_property_read_u32(np, "atmel,flexcom-mode", &opmode);
+	if (err)
+		return err;
+
+	if (opmode < ATMEL_FLEXCOM_MODE_USART ||
+	    opmode > ATMEL_FLEXCOM_MODE_TWI)
+		return -EINVAL;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk))
+		return PTR_ERR(clk);
+
+	err = clk_prepare_enable(clk);
+	if (err)
+		return err;
+
+	/*
+	 * Set the Operating Mode in the Mode Register: only the selected device
+	 * is clocked. Hence, registers of the other serial devices remain
+	 * inaccessible and are read as zero. Also the external I/O lines of the
+	 * Flexcom are muxed to reach the selected device.
+	 */
+	writel(FLEX_MR_OPMODE(opmode), base + FLEX_MR);
+
+	clk_disable_unprepare(clk);
+
+	return of_platform_populate(np, NULL, NULL, &pdev->dev);
+}
+
+static const struct of_device_id atmel_flexcom_of_match[] = {
+	{ .compatible = "atmel,sama5d2-flexcom" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match);
+
+static struct platform_driver atmel_flexcom_driver = {
+	.probe	= atmel_flexcom_probe,
+	.driver	= {
+		.name		= "atmel_flexcom",
+		.of_match_table	= atmel_flexcom_of_match,
+	},
+};
+
+module_platform_driver(atmel_flexcom_driver);
+
+MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
+MODULE_DESCRIPTION("Atmel Flexcom MFD driver");
+MODULE_LICENSE("GPL v2");
-- 
1.8.2.2