* [PATCH v3 1/7] dt-bindings: document devicetree bindings for mux-controllers and mux-gpio
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
@ 2016-11-21 13:17 ` Peter Rosin
2016-11-21 13:17 ` [PATCH v3 2/7] misc: minimal mux subsystem and gpio-based mux controller Peter Rosin
` (6 subsequent siblings)
7 siblings, 0 replies; 14+ messages in thread
From: Peter Rosin @ 2016-11-21 13:17 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, Jonathan Corbet, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio, linux-doc
Signed-off-by: Peter Rosin <peda@axentia.se>
---
.../devicetree/bindings/misc/mux-controller.txt | 76 +++++++++++++++++++++
.../devicetree/bindings/misc/mux-gpio.txt | 78 ++++++++++++++++++++++
MAINTAINERS | 5 ++
3 files changed, 159 insertions(+)
create mode 100644 Documentation/devicetree/bindings/misc/mux-controller.txt
create mode 100644 Documentation/devicetree/bindings/misc/mux-gpio.txt
diff --git a/Documentation/devicetree/bindings/misc/mux-controller.txt b/Documentation/devicetree/bindings/misc/mux-controller.txt
new file mode 100644
index 000000000000..6946b5428546
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/mux-controller.txt
@@ -0,0 +1,76 @@
+Common multiplexer controller bindings
+
+A mux controller will have one, or several, child devices that uses (or
+consumes) a mux controller. A mux controller can possibly control several
+parallel multiplexers. The node for a mux controller will have one child
+node for each multiplexer controller consumer.
+
+A mux controller provides a number of states to its consumers, and the
+state space is a simple zero-based enumeration. I.e. 0-1 for a 2-way
+multiplexer, 0-7 for an 8-way multiplexer, etc.
+
+Example:
+
+ /*
+ * Two consumers (one for an ADC line and one for an i2c bus) of
+ * parallel 4-way multiplexers controlled by the same two GPIO-lines.
+ */
+ mux {
+ compatible = "mux-gpio";
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+ <&pioA 1 GPIO_ACTIVE_HIGH>;
+
+ adc {
+ compatible = "iio-mux";
+ io-channels = <&adc 0>;
+ io-channel-names = "parent";
+
+ #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>;
+
+ #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 {
+ /* ... */
+ };
+ };
+ };
+ };
diff --git a/Documentation/devicetree/bindings/misc/mux-gpio.txt b/Documentation/devicetree/bindings/misc/mux-gpio.txt
new file mode 100644
index 000000000000..23b87913f4b3
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/mux-gpio.txt
@@ -0,0 +1,78 @@
+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.
+* Standard mux-controller bindings as decribed in mux-controller.txt
+
+Optional properties:
+- idle-state : if present, the state the mux will have when idle.
+
+The multiplexer state is defined as the number represented by the
+multiplexer GPIO pins, where the first pin is the least significant
+bit. And active pin is a binary 1, an inactive pin is a binary 0.
+
+Example:
+ mux {
+ compatible = "mux-gpio";
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+ <&pioA 1 GPIO_ACTIVE_HIGH>;
+
+ adc {
+ compatible = "iio-mux";
+ io-channels = <&adc 0>;
+ io-channel-names = "parent";
+
+ #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>;
+
+ #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 {
+ /* ... */
+ };
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index ad9b965e5e44..7d797f087822 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8244,6 +8244,11 @@ S: Orphan
F: drivers/mmc/host/mmc_spi.c
F: include/linux/spi/mmc_spi.h
+MULTIPLEXER SUBSYSTEM
+M: Peter Rosin <peda@axentia.se>
+S: Maintained
+F: Documentation/devicetree/bindings/misc/mux-*
+
MULTISOUND SOUND DRIVER
M: Andrew Veliath <andrewtv@usa.net>
S: Maintained
--
2.1.4
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 2/7] misc: minimal mux subsystem and gpio-based mux controller
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
2016-11-21 13:17 ` [PATCH v3 1/7] dt-bindings: document devicetree bindings for mux-controllers and mux-gpio Peter Rosin
@ 2016-11-21 13:17 ` Peter Rosin
2016-11-21 13:17 ` [PATCH v3 3/7] iio: inkern: api for manipulating ext_info of iio channels Peter Rosin
` (5 subsequent siblings)
7 siblings, 0 replies; 14+ messages in thread
From: Peter Rosin @ 2016-11-21 13:17 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, Jonathan Corbet, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio, linux-doc
Add a new minimalistic subsystem that handles multiplexer controllers.
When multiplexers are used in various places in the kernel, and the
same multiplexer controller can be used for several independent things,
there should be one place to implement support for said multiplexer
controller.
A single multiplexer controller can also be used to control several
parallel multiplexers, that are in turn used by different subsystems
in the kernel, leading to a need to coordinate multiplexer accesses.
The multiplexer subsystem handles this coordination.
This new mux controller subsystem comes with a single backend driver
that controls gpio based multiplexers.
Signed-off-by: Peter Rosin <peda@axentia.se>
---
Documentation/driver-model/devres.txt | 6 +-
MAINTAINERS | 2 +
drivers/misc/Kconfig | 23 +++
drivers/misc/Makefile | 2 +
drivers/misc/mux-core.c | 325 ++++++++++++++++++++++++++++++++++
drivers/misc/mux-gpio.c | 116 ++++++++++++
include/linux/mux.h | 55 ++++++
7 files changed, 528 insertions(+), 1 deletion(-)
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/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt
index 167070895498..947bfcfac9ae 100644
--- a/Documentation/driver-model/devres.txt
+++ b/Documentation/driver-model/devres.txt
@@ -330,7 +330,11 @@ MEM
devm_kzalloc()
MFD
- devm_mfd_add_devices()
+ devm_mfd_add_devices()
+
+MUX
+ devm_mux_control_get()
+ devm_mux_control_put()
PCI
pcim_enable_device() : after success, all PCI ops become managed
diff --git a/MAINTAINERS b/MAINTAINERS
index 7d797f087822..37974aeee750 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8248,6 +8248,8 @@ MULTIPLEXER SUBSYSTEM
M: Peter Rosin <peda@axentia.se>
S: Maintained
F: Documentation/devicetree/bindings/misc/mux-*
+F: include/linux/mux.h
+F: drivers/misc/mux-*
MULTISOUND SOUND DRIVER
M: Andrew Veliath <andrewtv@usa.net>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 64971baf11fa..a3ca79e082c7 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -766,6 +766,29 @@ 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 MULTIPLEXER
+ tristate "Multiplexer subsystem"
+ help
+ Multiplexer controller subsystem. Multiplexers are used in a
+ variety of settings, and this subsystem abstracts their use
+ so that the rest of the kernel sees a common interface. When
+ multiple parallel multiplexers are controlled by one single
+ multiplexer controller, this subsystem also coordinates the
+ multiplexer accesses.
+
+if MULTIPLEXER
+
+config MUX_GPIO
+ tristate "GPIO-controlled MUX controller"
+ depends on OF && GPIOLIB
+ help
+ GPIO-controlled MUX controller.
+
+ To compile this driver as a module, choose M here: the module will
+ be called mux-gpio.
+
+endif
+
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..0befa2bba762 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-$(CONFIG_MULTIPLEXER) += mux-core.o
+obj-$(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..5142caa19236
--- /dev/null
+++ b/drivers/misc/mux-core.c
@@ -0,0 +1,325 @@
+/*
+ * 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/of_platform.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,
+};
+
+/**
+ * mux_control_alloc - allocate a mux-control
+ * @sizeof_priv: Size of extra memory area for private use by the caller.
+ *
+ * Returns the new mux-control.
+ */
+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->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);
+
+/**
+ * mux_control_register - register a mux-control, thus readying it for use
+ * @mux: The mux-control to register.
+ *
+ * Returns zero on success or a negative errno on error.
+ */
+int mux_control_register(struct mux_control *mux)
+{
+ int ret;
+
+ /* 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;
+
+ ret = device_add(&mux->dev);
+ if (ret < 0)
+ return ret;
+
+ ret = of_platform_populate(mux->dev.of_node, NULL, NULL, &mux->dev);
+ if (ret < 0)
+ device_del(&mux->dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(mux_control_register);
+
+/**
+ * mux_control_unregister - take the mux-control off-line, reversing the
+ * effexts of mux_control_register
+ * @mux: the mux-control to unregister.
+ */
+void mux_control_unregister(struct mux_control *mux)
+{
+ of_platform_depopulate(&mux->dev);
+ device_del(&mux->dev);
+}
+EXPORT_SYMBOL_GPL(mux_control_unregister);
+
+/**
+ * mux_control_put - put away the mux-control for good, reversing the
+ * effects of either mux_control_alloc or mux_control_get
+ * @mux: The mux-control to put away.
+ */
+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;
+}
+
+/**
+ * mux_control_select - select the given multiplexer state
+ * @mux: The mux-control to request a change of state from.
+ * @state: The new requested state.
+ *
+ * Returns 0 if the requested state was already active, or 1 it the
+ * mux-control state was changed to the requested state. Or a negavive
+ * errno on error.
+ * Note that the difference in return value of zero or one is of
+ * questionable value; especially if the mux-control has several independent
+ * consumers, which is something the consumers should not be making
+ * assumptions about.
+ *
+ * Make sure to call mux_control_deselect when the operation is complete and
+ * the mux-control is free for others to use, but do not call
+ * mux_control_deselect if mux_control_select fails.
+ */
+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);
+
+/**
+ * mux_control_deselect - deselect the previously selected multiplexer state
+ * @mux: The mux-control to deselect.
+ *
+ * Returns 0 on success and a negative errno on error. An error can only
+ * occur if the mux has an idle state. Note that even if an error occurs, the
+ * mux-control is unlocked for others to access.
+ */
+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;
+}
+
+/**
+ * mux_control_get - get the mux-control for a device
+ * @dev: The device that needs a mux-control.
+ *
+ * Returns the mux-control.
+ */
+struct mux_control *mux_control_get(struct device *dev)
+{
+ struct mux_control *mux;
+
+ if (!dev->of_node)
+ return ERR_PTR(-ENODEV);
+
+ mux = of_find_mux_by_node(dev->of_node->parent);
+ 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);
+}
+
+/**
+ * devm_mux_control_get - get the mux-control for a device, with resource
+ * management
+ * @dev: The device that needs a mux-control.
+ *
+ * Returns the mux-control.
+ */
+struct mux_control *devm_mux_control_get(struct device *dev)
+{
+ 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);
+ 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;
+}
+
+/**
+ * devm_mux_control_put - resource-managed version mux_control_put
+ * @dev: The device that originally got the mux-control.
+ * @mux: The mux-control to put away.
+ *
+ * Note that you do not normally need to call this function.
+ */
+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@axentia.se");
+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..e9baca35f400
--- /dev/null
+++ b/drivers/misc/mux-gpio.c
@@ -0,0 +1,116 @@
+/*
+ * 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_control_priv(mux);
+ 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_control_priv(mux);
+ 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);
+ }
+ mux->states = 1 << mux_gpio->gpios->ndescs;
+
+ ret = of_property_read_u32(np, "idle-state", &idle_state);
+ if (ret >= 0) {
+ if (idle_state >= mux->states) {
+ 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@axentia.se");
+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..2f1472192d6d
--- /dev/null
+++ b/include/linux/mux.h
@@ -0,0 +1,55 @@
+/*
+ * 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;
+
+ unsigned int states;
+ int cached_state;
+ int idle_state;
+
+ const struct mux_control_ops *ops;
+};
+
+#define to_mux_control(x) container_of((x), struct mux_control, dev)
+
+static inline void *mux_control_priv(struct mux_control *mux)
+{
+ return mux + 1;
+}
+
+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);
+struct mux_control *devm_mux_control_get(struct device *dev);
+void devm_mux_control_put(struct device *dev, struct mux_control *mux);
+
+#endif /* _LINUX_MUX_H */
--
2.1.4
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 3/7] iio: inkern: api for manipulating ext_info of iio channels
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
2016-11-21 13:17 ` [PATCH v3 1/7] dt-bindings: document devicetree bindings for mux-controllers and mux-gpio Peter Rosin
2016-11-21 13:17 ` [PATCH v3 2/7] misc: minimal mux subsystem and gpio-based mux controller Peter Rosin
@ 2016-11-21 13:17 ` Peter Rosin
2016-11-21 13:17 ` [PATCH v3 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings Peter Rosin
` (4 subsequent siblings)
7 siblings, 0 replies; 14+ messages in thread
From: Peter Rosin @ 2016-11-21 13:17 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, Jonathan Corbet, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio, linux-doc
Extend the inkern api with functions for reading and writing ext_info
of iio channels.
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/iio/inkern.c | 55 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/iio/consumer.h | 37 +++++++++++++++++++++++++++++
2 files changed, 92 insertions(+)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index c4757e6367e7..efe418282cc3 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -746,3 +746,58 @@ 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 9edccfba1ffb..1e908ccb11f0 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -271,4 +271,41 @@ 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);
+/**
+ * iio_get_channel_ext_info_count() - get number of ext_info attributes
+ * connected to the channel.
+ * @chan: The channel being queried
+ *
+ * Returns the number of ext_info attributes
+ */
+int iio_get_channel_ext_info_count(struct iio_channel *chan);
+
+/**
+ * iio_read_channel_ext_info() - read ext_info attribute from a given channel
+ * @chan: The channel being queried.
+ * @attr: The ext_info attribute to read.
+ * @buf: Where to store the attribute value. Assumed to hold
+ * at least PAGE_SIZE bytes.
+ *
+ * Returns the number of bytes written to buf (perhaps w/o zero termination;
+ * it need not even be a string), or an error code.
+ */
+ssize_t iio_read_channel_ext_info(struct iio_channel *chan,
+ const char *attr, char *buf);
+
+/**
+ * iio_write_channel_ext_info() - write ext_info attribute from a given channel
+ * @chan: The channel being queried.
+ * @attr: The ext_info attribute to read.
+ * @buf: The new attribute value. Strings needs to be zero-
+ * terminated, but the terminator should not be included
+ * in the below len.
+ * @len: The size of the new attribute value.
+ *
+ * Returns the number of accepted bytes, which should be the same as len.
+ * An error code can also be returned.
+ */
+ssize_t iio_write_channel_ext_info(struct iio_channel *chan, const char *attr,
+ const char *buf, size_t len);
+
#endif
--
2.1.4
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
` (2 preceding siblings ...)
2016-11-21 13:17 ` [PATCH v3 3/7] iio: inkern: api for manipulating ext_info of iio channels Peter Rosin
@ 2016-11-21 13:17 ` Peter Rosin
2016-11-21 13:17 ` [PATCH v3 5/7] iio: multiplexer: new iio category and iio-mux driver Peter Rosin
` (3 subsequent siblings)
7 siblings, 0 replies; 14+ messages in thread
From: Peter Rosin @ 2016-11-21 13:17 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, Jonathan Corbet, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio, linux-doc
Signed-off-by: Peter Rosin <peda@axentia.se>
---
.../bindings/iio/multiplexer/iio-mux.txt | 47 ++++++++++++++++++++++
MAINTAINERS | 6 +++
2 files changed, 53 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..2807333ccc86
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
@@ -0,0 +1,47 @@
+IIO multiplexer bindings
+
+If a multiplexer is used to select which 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".
+- #address-cells = <1>;
+- #size-cells = <0>;
+
+Required properties for iio-mux child nodes:
+- reg : The multiplexer state as described in ../misc/mux-controller.txt
+
+For each iio-mux child, an iio channel will be created whose number will
+match the mux controller state.
+
+Example:
+ mux {
+ compatible = "mux-gpio";
+
+ mux-gpios = <&pioA 0 GPIO_ACTIVE_HIGH>,
+ <&pioA 1 GPIO_ACTIVE_HIGH>;
+
+ adc {
+ compatible = "iio-mux";
+ io-channels = <&adc 0>;
+ io-channel-names = "parent";
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ sync@0 {
+ reg = <0>;
+ };
+
+ in@1 {
+ reg = <1>;
+ };
+
+ system-regulator@2 {
+ reg = <2>;
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 37974aeee750..3fc0dbbc04ea 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6124,6 +6124,12 @@ L: linux-media@vger.kernel.org
S: Maintained
F: drivers/media/rc/iguanair.c
+IIO MULTIPLEXER
+M: Peter Rosin <peda@axentia.se>
+L: linux-iio@vger.kernel.org
+S: Maintained
+F: Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
+
IIO SUBSYSTEM AND DRIVERS
M: Jonathan Cameron <jic23@kernel.org>
R: Hartmut Knaack <knaack.h@gmx.de>
--
2.1.4
^ permalink raw reply related [flat|nested] 14+ messages in thread* [PATCH v3 5/7] iio: multiplexer: new iio category and iio-mux driver
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
` (3 preceding siblings ...)
2016-11-21 13:17 ` [PATCH v3 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings Peter Rosin
@ 2016-11-21 13:17 ` Peter Rosin
2016-11-21 14:33 ` kbuild test robot
2016-11-21 13:17 ` [PATCH v3 6/7] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings Peter Rosin
` (2 subsequent siblings)
7 siblings, 1 reply; 14+ messages in thread
From: Peter Rosin @ 2016-11-21 13:17 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, Jonathan Corbet, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio, linux-doc
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 subsystem.
Cache any ext_info values from the parent iio channel, creating a private
copy of the ext_info attributes for each multiplexer state/channel.
Signed-off-by: Peter Rosin <peda@axentia.se>
---
MAINTAINERS | 1 +
drivers/iio/Kconfig | 1 +
drivers/iio/Makefile | 1 +
drivers/iio/multiplexer/Kconfig | 18 ++
drivers/iio/multiplexer/Makefile | 6 +
drivers/iio/multiplexer/iio-mux.c | 450 ++++++++++++++++++++++++++++++++++++++
6 files changed, 477 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/MAINTAINERS b/MAINTAINERS
index 3fc0dbbc04ea..02d9072aae16 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6129,6 +6129,7 @@ M: Peter Rosin <peda@axentia.se>
L: linux-iio@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/iio/multiplexer/iio-mux.txt
+F: drivers/iio/multiplexer/iio-mux.c
IIO SUBSYSTEM AND DRIVERS
M: Jonathan Cameron <jic23@kernel.org>
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..70a044510686
--- /dev/null
+++ b/drivers/iio/multiplexer/Kconfig
@@ -0,0 +1,18 @@
+#
+# Multiplexer drivers
+#
+# When adding new entries keep the list in alphabetical order
+
+menu "Multiplexers"
+
+config IIO_MUX
+ tristate "IIO multiplexer driver"
+ select MULTIPLEXER
+ depends on OF
+ 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..0b9d04914241
--- /dev/null
+++ b/drivers/iio/multiplexer/iio-mux.c
@@ -0,0 +1,450 @@
+/*
+ * 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 {
+ struct mux_ext_info_cache *ext_info_cache;
+};
+
+struct mux {
+ int cached_state;
+ struct mux_control *control;
+ struct iio_channel *parent;
+ struct iio_dev *indio_dev;
+ struct iio_chan_spec *chan;
+ 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];
+ struct iio_chan_spec const *chan = &mux->chan[idx];
+ int ret;
+ int i;
+
+ ret = mux_control_select(mux->control, chan->channel);
+ if (ret < 0) {
+ mux->cached_state = -1;
+ return ret;
+ }
+
+ if (mux->cached_state == chan->channel)
+ return 0;
+
+ if (chan->ext_info) {
+ for (i = 0; chan->ext_info[i].name; ++i) {
+ const char *attr = chan->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 = chan->channel;
+
+ 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->chan;
+ 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->chan;
+ 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->chan;
+ 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->chan;
+ 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->chan;
+ 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 *chan = &mux->chan[idx];
+ struct iio_chan_spec const *pchan = mux->parent->channel;
+ u32 state;
+ char *page = NULL;
+ int num_ext_info;
+ int i;
+ int ret;
+
+ chan->indexed = 1;
+ chan->output = pchan->output;
+ chan->datasheet_name = child_np->name;
+ chan->ext_info = mux->ext_info;
+
+ ret = iio_get_channel_type(mux->parent, &chan->type);
+ if (ret < 0) {
+ dev_err(dev, "failed to get parent channel type\n");
+ return ret;
+ }
+
+ if (iio_channel_has_info(pchan, IIO_CHAN_INFO_RAW))
+ chan->info_mask_separate |= BIT(IIO_CHAN_INFO_RAW);
+ if (iio_channel_has_info(pchan, IIO_CHAN_INFO_SCALE))
+ chan->info_mask_separate |= BIT(IIO_CHAN_INFO_SCALE);
+
+ if (iio_channel_has_available(pchan, IIO_CHAN_INFO_RAW))
+ chan->info_mask_separate_available |= BIT(IIO_CHAN_INFO_RAW);
+
+ ret = of_property_read_u32(child_np, "reg", &state);
+ if (ret < 0) {
+ dev_err(dev, "no reg property for node '%s'\n", child_np->name);
+ return ret;
+ }
+
+ if (state >= mux->control->states) {
+ dev_err(dev, "invalid reg %u\n", state);
+ return -EINVAL;
+ }
+
+ for (i = 0; i < idx; ++i) {
+ if (mux->chan[i].channel == state) {
+ dev_err(dev, "double use of reg %u\n", state);
+ return -EINVAL;
+ }
+ }
+
+ chan->channel = state;
+
+ 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 (!pchan->ext_info[i].write)
+ continue;
+ if (!pchan->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",
+ pchan->ext_info[i].name);
+ return ret;
+ }
+ if (ret >= PAGE_SIZE) {
+ dev_err(dev, "too large ext_info '%s'\n",
+ pchan->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 (page)
+ 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->chan) * 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->chan = (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->chan;
+ 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;
+ }
+ }
+
+ mux->control = devm_mux_control_get(dev);
+ 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);
+ }
+
+ 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++;
+ }
+
+ 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 [flat|nested] 14+ messages in thread* Re: [PATCH v3 5/7] iio: multiplexer: new iio category and iio-mux driver
2016-11-21 13:17 ` [PATCH v3 5/7] iio: multiplexer: new iio category and iio-mux driver Peter Rosin
@ 2016-11-21 14:33 ` kbuild test robot
0 siblings, 0 replies; 14+ messages in thread
From: kbuild test robot @ 2016-11-21 14:33 UTC (permalink / raw)
Cc: kbuild-all, linux-kernel, Peter Rosin, Wolfram Sang, Rob Herring,
Mark Rutland, Jonathan Cameron, Hartmut Knaack,
Lars-Peter Clausen, Peter Meerwald-Stadler, Jonathan Corbet,
Arnd Bergmann, Greg Kroah-Hartman, linux-i2c, devicetree,
linux-iio, linux-doc
[-- Attachment #1: Type: text/plain, Size: 6412 bytes --]
Hi Peter,
[auto build test ERROR on linus/master]
[also build test ERROR on v4.9-rc6]
[cannot apply to next-20161117]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/Peter-Rosin/mux-controller-abstraction-and-iio-i2c-muxes/20161121-215311
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All errors (new ones prefixed by >>):
drivers/iio/multiplexer/iio-mux.c: In function 'mux_read_avail':
>> drivers/iio/multiplexer/iio-mux.c:134:9: error: implicit declaration of function 'iio_read_avail_channel_raw' [-Werror=implicit-function-declaration]
ret = iio_read_avail_channel_raw(mux->parent, vals, length);
^~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/iio/multiplexer/iio-mux.c: At top level:
>> drivers/iio/multiplexer/iio-mux.c:174:2: error: unknown field 'read_avail' specified in initializer
.read_avail = mux_read_avail,
^
>> drivers/iio/multiplexer/iio-mux.c:174:16: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
.read_avail = mux_read_avail,
^~~~~~~~~~~~~~
drivers/iio/multiplexer/iio-mux.c:174:16: note: (near initialization for 'mux_info.read_raw_multi')
drivers/iio/multiplexer/iio-mux.c: In function 'mux_configure_channel':
>> drivers/iio/multiplexer/iio-mux.c:267:6: error: implicit declaration of function 'iio_channel_has_available' [-Werror=implicit-function-declaration]
if (iio_channel_has_available(pchan, IIO_CHAN_INFO_RAW))
^~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/iio/multiplexer/iio-mux.c:268:7: error: 'struct iio_chan_spec' has no member named 'info_mask_separate_available'; did you mean 'info_mask_separate'?
chan->info_mask_separate_available |= BIT(IIO_CHAN_INFO_RAW);
^~
cc1: some warnings being treated as errors
vim +/iio_read_avail_channel_raw +134 drivers/iio/multiplexer/iio-mux.c
128 if (ret < 0)
129 return ret;
130
131 switch (mask) {
132 case IIO_CHAN_INFO_RAW:
133 *type = IIO_VAL_INT;
> 134 ret = iio_read_avail_channel_raw(mux->parent, vals, length);
135 break;
136
137 default:
138 ret = -EINVAL;
139 }
140
141 iio_mux_deselect(mux);
142
143 return ret;
144 }
145
146 static int mux_write_raw(struct iio_dev *indio_dev,
147 struct iio_chan_spec const *chan,
148 int val, int val2, long mask)
149 {
150 struct mux *mux = iio_priv(indio_dev);
151 int idx = chan - mux->chan;
152 int ret;
153
154 ret = iio_mux_select(mux, idx);
155 if (ret < 0)
156 return ret;
157
158 switch (mask) {
159 case IIO_CHAN_INFO_RAW:
160 ret = iio_write_channel_raw(mux->parent, val);
161 break;
162
163 default:
164 ret = -EINVAL;
165 }
166
167 iio_mux_deselect(mux);
168
169 return ret;
170 }
171
172 static const struct iio_info mux_info = {
173 .read_raw = mux_read_raw,
> 174 .read_avail = mux_read_avail,
175 .write_raw = mux_write_raw,
176 .driver_module = THIS_MODULE,
177 };
178
179 static ssize_t mux_read_ext_info(struct iio_dev *indio_dev, uintptr_t private,
180 struct iio_chan_spec const *chan, char *buf)
181 {
182 struct mux *mux = iio_priv(indio_dev);
183 int idx = chan - mux->chan;
184 ssize_t ret;
185
186 ret = iio_mux_select(mux, idx);
187 if (ret < 0)
188 return ret;
189
190 ret = iio_read_channel_ext_info(mux->parent,
191 mux->ext_info[private].name,
192 buf);
193
194 iio_mux_deselect(mux);
195
196 return ret;
197 }
198
199 static ssize_t mux_write_ext_info(struct iio_dev *indio_dev, uintptr_t private,
200 struct iio_chan_spec const *chan,
201 const char *buf, size_t len)
202 {
203 struct device *dev = indio_dev->dev.parent;
204 struct mux *mux = iio_priv(indio_dev);
205 int idx = chan - mux->chan;
206 char *new;
207 ssize_t ret;
208
209 ret = iio_mux_select(mux, idx);
210 if (ret < 0)
211 return ret;
212
213 new = devm_kmemdup(dev, buf, len + 1, GFP_KERNEL);
214 if (!new) {
215 iio_mux_deselect(mux);
216 return -ENOMEM;
217 }
218
219 new[len] = 0;
220
221 ret = iio_write_channel_ext_info(mux->parent,
222 mux->ext_info[private].name,
223 buf, len);
224 if (ret < 0) {
225 iio_mux_deselect(mux);
226 devm_kfree(dev, new);
227 return ret;
228 }
229
230 devm_kfree(dev, mux->child[idx].ext_info_cache[private].data);
231 mux->child[idx].ext_info_cache[private].data = new;
232 mux->child[idx].ext_info_cache[private].size = len;
233
234 iio_mux_deselect(mux);
235
236 return ret;
237 }
238
239 static int mux_configure_channel(struct device *dev, struct mux *mux,
240 struct device_node *child_np, int idx)
241 {
242 struct mux_child *child = &mux->child[idx];
243 struct iio_chan_spec *chan = &mux->chan[idx];
244 struct iio_chan_spec const *pchan = mux->parent->channel;
245 u32 state;
246 char *page = NULL;
247 int num_ext_info;
248 int i;
249 int ret;
250
251 chan->indexed = 1;
252 chan->output = pchan->output;
253 chan->datasheet_name = child_np->name;
254 chan->ext_info = mux->ext_info;
255
256 ret = iio_get_channel_type(mux->parent, &chan->type);
257 if (ret < 0) {
258 dev_err(dev, "failed to get parent channel type\n");
259 return ret;
260 }
261
262 if (iio_channel_has_info(pchan, IIO_CHAN_INFO_RAW))
263 chan->info_mask_separate |= BIT(IIO_CHAN_INFO_RAW);
264 if (iio_channel_has_info(pchan, IIO_CHAN_INFO_SCALE))
265 chan->info_mask_separate |= BIT(IIO_CHAN_INFO_SCALE);
266
> 267 if (iio_channel_has_available(pchan, IIO_CHAN_INFO_RAW))
> 268 chan->info_mask_separate_available |= BIT(IIO_CHAN_INFO_RAW);
269
270 ret = of_property_read_u32(child_np, "reg", &state);
271 if (ret < 0) {
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 56692 bytes --]
^ permalink raw reply [flat|nested] 14+ messages in thread
* [PATCH v3 6/7] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
` (4 preceding siblings ...)
2016-11-21 13:17 ` [PATCH v3 5/7] iio: multiplexer: new iio category and iio-mux driver Peter Rosin
@ 2016-11-21 13:17 ` Peter Rosin
2016-11-21 13:17 ` [PATCH v3 7/7] i2c: i2c-mux-simple: new driver Peter Rosin
2016-11-22 20:58 ` [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Lars-Peter Clausen
7 siblings, 0 replies; 14+ messages in thread
From: Peter Rosin @ 2016-11-21 13:17 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, Jonathan Corbet, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio, linux-doc
Signed-off-by: Peter Rosin <peda@axentia.se>
---
.../devicetree/bindings/i2c/i2c-mux-simple.txt | 76 ++++++++++++++++++++++
1 file changed, 76 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..decfd742b297
--- /dev/null
+++ b/Documentation/devicetree/bindings/i2c/i2c-mux-simple.txt
@@ -0,0 +1,76 @@
+Simple I2C Bus Mux
+
+This binding describes an I2C bus multiplexer that uses a mux controller
+from the mux subsystem 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.
+* Standard I2C mux properties. See i2c-mux.txt in this directory.
+* I2C child bus nodes. See i2c-mux.txt in this directory. The sub-bus number
+ is also the mux-controller state described in ../misc/mux-controller.txt
+
+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 set as the state in the
+mux controller.
+
+Example:
+ 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>;
+
+ #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 [flat|nested] 14+ messages in thread* [PATCH v3 7/7] i2c: i2c-mux-simple: new driver
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
` (5 preceding siblings ...)
2016-11-21 13:17 ` [PATCH v3 6/7] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings Peter Rosin
@ 2016-11-21 13:17 ` Peter Rosin
2016-11-22 20:58 ` [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Lars-Peter Clausen
7 siblings, 0 replies; 14+ messages in thread
From: Peter Rosin @ 2016-11-21 13:17 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, Jonathan Corbet, Arnd Bergmann,
Greg Kroah-Hartman, linux-i2c, devicetree, linux-iio, linux-doc
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.
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/i2c/muxes/Kconfig | 13 +++
drivers/i2c/muxes/Makefile | 1 +
drivers/i2c/muxes/i2c-mux-simple.c | 177 +++++++++++++++++++++++++++++++++++++
3 files changed, 191 insertions(+)
create mode 100644 drivers/i2c/muxes/i2c-mux-simple.c
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
index 96de9ce5669b..fb4f587d822a 100644
--- a/drivers/i2c/muxes/Kconfig
+++ b/drivers/i2c/muxes/Kconfig
@@ -73,6 +73,19 @@ 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"
+ select 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..a2f1dc8a3295
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-simple.c
@@ -0,0 +1,177 @@
+/*
+ * 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);
+ 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) {
+ dev_err(dev, "no reg property for node '%s'\n",
+ child->name);
+ goto err_children;
+ }
+
+ if (chan >= mux->control->states) {
+ dev_err(dev, "invalid reg %u\n", chan);
+ ret = -EINVAL;
+ 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 [flat|nested] 14+ messages in thread* Re: [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes
2016-11-21 13:17 [PATCH v3 0/7] mux controller abstraction and iio/i2c muxes Peter Rosin
` (6 preceding siblings ...)
2016-11-21 13:17 ` [PATCH v3 7/7] i2c: i2c-mux-simple: new driver Peter Rosin
@ 2016-11-22 20:58 ` Lars-Peter Clausen
[not found] ` <b132143c-259b-6ed2-58c5-b223cc2e72df-Qo5EllUWu/uELgA04lAiVw@public.gmane.org>
7 siblings, 1 reply; 14+ messages in thread
From: Lars-Peter Clausen @ 2016-11-22 20:58 UTC (permalink / raw)
To: Peter Rosin, linux-kernel
Cc: Wolfram Sang, Rob Herring, Mark Rutland, Jonathan Cameron,
Hartmut Knaack, Peter Meerwald-Stadler, Jonathan Corbet,
Arnd Bergmann, Greg Kroah-Hartman, linux-i2c, devicetree,
linux-iio, linux-doc
On 11/21/2016 02:17 PM, Peter Rosin wrote:
[...]
> 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 (and subsystem) 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).
While abstracting this properly is all nice and good and the way it should
be done, but it also adds a lot of complexity and the devicetree adds a lot
of restrictions on what can actually be represented.
There is a certain point where the fabric on a PCB becomes so complex that
it deserves to be a device on its own (like the audio fabric drivers).
Especially when the hardware is built with a certain application in mind and
the driver is supposed to impose policy which reflects this application. The
latter can often not properly be described with the primitives the
devicetree can offer.
And I think your setup is very borderline what can be done in a declarative
way only and it adds a lot of complexity over a more imperative solution in
form of a driver. I think it is worth investigating about having a driver
that is specific to your fabric and handles the interdependencies of the
discrete components.
^ permalink raw reply [flat|nested] 14+ messages in thread