* [RFC PATCH 2/7] misc: minimal mux subsystem and gpio-based mux controller
[not found] ` <1479340111-1259-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
@ 2016-11-16 23:48 ` Peter Rosin
2016-11-16 23:48 ` [RFC PATCH 3/7] iio: inkern: api for manipulating ext_info of iio channels Peter Rosin
` (4 subsequent siblings)
5 siblings, 0 replies; 10+ messages in thread
From: Peter Rosin @ 2016-11-16 23:48 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
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 | 285 ++++++++++++++++++++++++++++++++++++++++++++++++
drivers/misc/mux-gpio.c | 105 ++++++++++++++++++
include/linux/mux.h | 54 +++++++++
5 files changed, 452 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..d7c7b667d1a4
--- /dev/null
+++ b/drivers/misc/mux-core.c
@@ -0,0 +1,285 @@
+/*
+ * 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);
+
+ 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_free);
+
+/*
+ * 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 reg)
+{
+ int ret;
+
+ if (down_read_trylock(&mux->lock)) {
+ if (mux->cache == reg)
+ return 0;
+
+ /* Sigh, the mux needs updating... */
+ up_read(&mux->lock);
+ }
+
+ /* ...or it's just contended. */
+ down_write(&mux->lock);
+
+ if (mux->cache == reg) {
+ /*
+ * 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->ops->set(mux, reg);
+ if (ret < 0) {
+ up_write(&mux->lock);
+ return ret;
+ }
+
+ mux->cache = reg;
+ 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)
+{
+ if (mux->do_idle && mux->cache != mux->idle_state) {
+ mux->ops->set(mux, mux->idle_state);
+ mux->cache = mux->idle_state;
+ }
+
+ up_read(&mux->lock);
+
+ return 0;
+}
+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..5fa59a0c49cf
--- /dev/null
+++ b/drivers/misc/mux-gpio.c
@@ -0,0 +1,105 @@
+/*
+ * 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;
+ 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 = 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..6513ffe749bb
--- /dev/null
+++ b/include/linux/mux.h
@@ -0,0 +1,54 @@
+/*
+ * 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 cache;
+ bool do_idle;
+ 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 reg);
+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
^ permalink raw reply related [flat|nested] 10+ messages in thread* [RFC PATCH 3/7] iio: inkern: api for manipulating ext_info of iio channels
[not found] ` <1479340111-1259-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
2016-11-16 23:48 ` [RFC PATCH 2/7] misc: minimal mux subsystem and gpio-based mux controller Peter Rosin
@ 2016-11-16 23:48 ` Peter Rosin
2016-11-16 23:48 ` [RFC PATCH 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings Peter Rosin
` (3 subsequent siblings)
5 siblings, 0 replies; 10+ messages in thread
From: Peter Rosin @ 2016-11-16 23:48 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
Extend the inkern api with functions for reading and writing ext_info
of iio channels.
---
drivers/iio/inkern.c | 40 ++++++++++++++++++++++++++++++++++++++++
include/linux/iio/consumer.h | 5 +++++
2 files changed, 45 insertions(+)
diff --git a/drivers/iio/inkern.c b/drivers/iio/inkern.c
index cfca17ba2535..5348735281ee 100644
--- a/drivers/iio/inkern.c
+++ b/drivers/iio/inkern.c
@@ -850,3 +850,43 @@ int iio_write_channel_raw(struct iio_channel *chan, int val)
return ret;
}
EXPORT_SYMBOL_GPL(iio_write_channel_raw);
+
+int 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);
+
+int 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..3859981cea0a 100644
--- a/include/linux/iio/consumer.h
+++ b/include/linux/iio/consumer.h
@@ -299,4 +299,9 @@ 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_read_channel_ext_info(struct iio_channel *chan,
+ const char *attr, char *buf);
+int 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] 10+ messages in thread* [RFC PATCH 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings
[not found] ` <1479340111-1259-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
2016-11-16 23:48 ` [RFC PATCH 2/7] misc: minimal mux subsystem and gpio-based mux controller Peter Rosin
2016-11-16 23:48 ` [RFC PATCH 3/7] iio: inkern: api for manipulating ext_info of iio channels Peter Rosin
@ 2016-11-16 23:48 ` Peter Rosin
2016-11-17 11:40 ` Lars-Peter Clausen
2016-11-16 23:48 ` [RFC PATCH 6/7] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings Peter Rosin
` (2 subsequent siblings)
5 siblings, 1 reply; 10+ messages in thread
From: Peter Rosin @ 2016-11-16 23:48 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
---
.../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.
+
+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>;
+ iio-ext-info = "invert", "1";
+ };
+
+ in@1 {
+ reg = <1>;
+ iio-ext-info = "invert", "1";
+ };
+
+ system-regulator@2 {
+ reg = <2>;
+ iio-ext-info = "invert", "0";
+ };
+ };
--
2.1.4
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^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [RFC PATCH 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings
2016-11-16 23:48 ` [RFC PATCH 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings Peter Rosin
@ 2016-11-17 11:40 ` Lars-Peter Clausen
0 siblings, 0 replies; 10+ messages in thread
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
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 [flat|nested] 10+ messages in thread
* [RFC PATCH 6/7] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings
[not found] ` <1479340111-1259-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
` (2 preceding siblings ...)
2016-11-16 23:48 ` [RFC PATCH 4/7] dt-bindings: iio: iio-mux: document iio-mux bindings Peter Rosin
@ 2016-11-16 23:48 ` Peter Rosin
2016-11-16 23:48 ` [RFC PATCH 7/7] i2c: i2c-mux-simple: new driver Peter Rosin
2016-11-17 9:33 ` [RFC PATCH 0/7] mux controller astraction and iio/i2c muxes Peter Rosin
5 siblings, 0 replies; 10+ messages in thread
From: Peter Rosin @ 2016-11-16 23:48 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
---
.../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
--
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^ permalink raw reply related [flat|nested] 10+ messages in thread* [RFC PATCH 7/7] i2c: i2c-mux-simple: new driver
[not found] ` <1479340111-1259-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
` (3 preceding siblings ...)
2016-11-16 23:48 ` [RFC PATCH 6/7] dt-bindings: i2c: i2c-mux-simple: document i2c-mux-simple bindings Peter Rosin
@ 2016-11-16 23:48 ` Peter Rosin
2016-11-17 9:33 ` [RFC PATCH 0/7] mux controller astraction and iio/i2c muxes Peter Rosin
5 siblings, 0 replies; 10+ messages in thread
From: Peter Rosin @ 2016-11-16 23:48 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
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 | 172 +++++++++++++++++++++++++++++++++++++
3 files changed, 185 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..308ecbf9d66c
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-simple.c
@@ -0,0 +1,172 @@
+/*
+ * Generic simple I2C multiplexer
+ *
+ * Peter Rosin <peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
+ *
+ * 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;
+
+ int parent;
+ int n_values;
+ u32 *values;
+};
+
+static int i2c_mux_select(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+
+ return mux_control_select(mux->control, chan);
+}
+
+static int i2c_mux_deselect(struct i2c_mux_core *muxc, u32 chan)
+{
+ struct mux *mux = i2c_mux_priv(muxc);
+
+ return mux_control_deselect(mux->control);
+}
+
+static int i2c_mux_probe_dt(struct mux *mux,
+ struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct device_node *adapter_np, *child;
+ struct i2c_adapter *adapter;
+ int i = 0;
+
+ if (!np)
+ return -ENODEV;
+
+ adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!adapter_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return -ENODEV;
+ }
+ adapter = of_find_i2c_adapter_by_node(adapter_np);
+ of_node_put(adapter_np);
+ if (!adapter)
+ return -EPROBE_DEFER;
+
+ mux->parent = i2c_adapter_id(adapter);
+ put_device(&adapter->dev);
+
+ 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);
+ }
+
+ mux->n_values = of_get_child_count(np);
+
+ mux->values = devm_kzalloc(dev,
+ sizeof(*mux->values) * mux->n_values,
+ GFP_KERNEL);
+ if (!mux->values)
+ return -ENOMEM;
+
+ for_each_child_of_node(np, child) {
+ of_property_read_u32(child, "reg", mux->values + i);
+ i++;
+ }
+
+ return 0;
+}
+
+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;
+ const struct of_device_id *match;
+ struct i2c_mux_core *muxc;
+ struct mux *mux;
+ struct i2c_adapter *parent;
+ int i, ret;
+
+ mux = devm_kzalloc(dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux)
+ return -ENOMEM;
+
+ ret = i2c_mux_probe_dt(mux, dev);
+ if (ret < 0)
+ return ret;
+
+ parent = i2c_get_adapter(mux->parent);
+ if (!parent)
+ return -EPROBE_DEFER;
+
+ muxc = i2c_mux_alloc(parent, dev, mux->n_values, 0, 0,
+ i2c_mux_select, i2c_mux_deselect);
+ if (!muxc) {
+ ret = -ENOMEM;
+ goto alloc_failed;
+ }
+ 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 (i = 0; i < mux->n_values; i++) {
+ ret = i2c_mux_add_adapter(muxc, 0, mux->values[i], 0);
+ if (ret)
+ goto add_adapter_failed;
+ }
+
+ dev_info(dev, "%d port mux on %s adapter\n",
+ mux->n_values, parent->name);
+
+ return 0;
+
+add_adapter_failed:
+ i2c_mux_del_adapters(muxc);
+alloc_failed:
+ 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-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>");
+MODULE_LICENSE("GPL v2");
--
2.1.4
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [RFC PATCH 0/7] mux controller astraction and iio/i2c muxes
[not found] ` <1479340111-1259-1-git-send-email-peda-koto5C5qi+TLoDKTGw+V6w@public.gmane.org>
` (4 preceding siblings ...)
2016-11-16 23:48 ` [RFC PATCH 7/7] i2c: i2c-mux-simple: new driver Peter Rosin
@ 2016-11-17 9:33 ` Peter Rosin
5 siblings, 0 replies; 10+ messages in thread
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
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"
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^ permalink raw reply [flat|nested] 10+ messages in thread