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-rw-r--r--drivers/i2c/muxes/Kconfig63
-rw-r--r--drivers/i2c/muxes/Makefile11
-rw-r--r--drivers/i2c/muxes/i2c-arb-gpio-challenge.c248
-rw-r--r--drivers/i2c/muxes/i2c-mux-gpio.c289
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca9541.c400
-rw-r--r--drivers/i2c/muxes/i2c-mux-pca954x.c314
-rw-r--r--drivers/i2c/muxes/i2c-mux-pinctrl.c277
7 files changed, 1602 insertions, 0 deletions
diff --git a/drivers/i2c/muxes/Kconfig b/drivers/i2c/muxes/Kconfig
new file mode 100644
index 000000000..f6d313e52
--- /dev/null
+++ b/drivers/i2c/muxes/Kconfig
@@ -0,0 +1,63 @@
+#
+# Multiplexer I2C chip drivers configuration
+#
+
+menu "Multiplexer I2C Chip support"
+ depends on I2C_MUX
+
+config I2C_ARB_GPIO_CHALLENGE
+ tristate "GPIO-based I2C arbitration"
+ depends on GPIOLIB && OF
+ help
+ If you say yes to this option, support will be included for an
+ I2C multimaster arbitration scheme using GPIOs and a challenge &
+ response mechanism where masters have to claim the bus by asserting
+ a GPIO.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-arb-gpio-challenge.
+
+config I2C_MUX_GPIO
+ tristate "GPIO-based I2C multiplexer"
+ depends on GPIOLIB
+ help
+ If you say yes to this option, support will be included for a
+ GPIO based I2C multiplexer. This driver provides access to
+ I2C busses connected through a MUX, which is controlled
+ through GPIO pins.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-gpio.
+
+config I2C_MUX_PCA9541
+ tristate "NXP PCA9541 I2C Master Selector"
+ help
+ If you say yes here you get support for the NXP PCA9541
+ I2C Master Selector.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-pca9541.
+
+config I2C_MUX_PCA954x
+ tristate "Philips PCA954x I2C Mux/switches"
+ depends on GPIOLIB
+ help
+ If you say yes here you get support for the Philips PCA954x
+ I2C mux/switch devices.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mux-pca954x.
+
+config I2C_MUX_PINCTRL
+ tristate "pinctrl-based I2C multiplexer"
+ depends on PINCTRL
+ help
+ If you say yes to this option, support will be included for an I2C
+ multiplexer that uses the pinctrl subsystem, i.e. pin multiplexing.
+ This is useful for SoCs whose I2C module's signals can be routed to
+ different sets of pins at run-time.
+
+ This driver can also be built as a module. If so, the module will be
+ called pinctrl-i2cmux.
+
+endmenu
diff --git a/drivers/i2c/muxes/Makefile b/drivers/i2c/muxes/Makefile
new file mode 100644
index 000000000..465778b5d
--- /dev/null
+++ b/drivers/i2c/muxes/Makefile
@@ -0,0 +1,11 @@
+#
+# Makefile for multiplexer I2C chip drivers.
+
+obj-$(CONFIG_I2C_ARB_GPIO_CHALLENGE) += i2c-arb-gpio-challenge.o
+
+obj-$(CONFIG_I2C_MUX_GPIO) += i2c-mux-gpio.o
+obj-$(CONFIG_I2C_MUX_PCA9541) += i2c-mux-pca9541.o
+obj-$(CONFIG_I2C_MUX_PCA954x) += i2c-mux-pca954x.o
+obj-$(CONFIG_I2C_MUX_PINCTRL) += i2c-mux-pinctrl.o
+
+ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG
diff --git a/drivers/i2c/muxes/i2c-arb-gpio-challenge.c b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
new file mode 100644
index 000000000..5cf1b60b6
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-arb-gpio-challenge.c
@@ -0,0 +1,248 @@
+/*
+ * GPIO-based I2C Arbitration Using a Challenge & Response Mechanism
+ *
+ * Copyright (C) 2012 Google, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <linux/kernel.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+
+/**
+ * struct i2c_arbitrator_data - Driver data for I2C arbitrator
+ *
+ * @parent: Parent adapter
+ * @child: Child bus
+ * @our_gpio: GPIO we'll use to claim.
+ * @our_gpio_release: 0 if active high; 1 if active low; AKA if the GPIO ==
+ * this then consider it released.
+ * @their_gpio: GPIO that the other side will use to claim.
+ * @their_gpio_release: 0 if active high; 1 if active low; AKA if the GPIO ==
+ * this then consider it released.
+ * @slew_delay_us: microseconds to wait for a GPIO to go high.
+ * @wait_retry_us: we'll attempt another claim after this many microseconds.
+ * @wait_free_us: we'll give up after this many microseconds.
+ */
+
+struct i2c_arbitrator_data {
+ struct i2c_adapter *parent;
+ struct i2c_adapter *child;
+ int our_gpio;
+ int our_gpio_release;
+ int their_gpio;
+ int their_gpio_release;
+ unsigned int slew_delay_us;
+ unsigned int wait_retry_us;
+ unsigned int wait_free_us;
+};
+
+
+/**
+ * i2c_arbitrator_select - claim the I2C bus
+ *
+ * Use the GPIO-based signalling protocol; return -EBUSY if we fail.
+ */
+static int i2c_arbitrator_select(struct i2c_adapter *adap, void *data, u32 chan)
+{
+ const struct i2c_arbitrator_data *arb = data;
+ unsigned long stop_retry, stop_time;
+
+ /* Start a round of trying to claim the bus */
+ stop_time = jiffies + usecs_to_jiffies(arb->wait_free_us) + 1;
+ do {
+ /* Indicate that we want to claim the bus */
+ gpio_set_value(arb->our_gpio, !arb->our_gpio_release);
+ udelay(arb->slew_delay_us);
+
+ /* Wait for the other master to release it */
+ stop_retry = jiffies + usecs_to_jiffies(arb->wait_retry_us) + 1;
+ while (time_before(jiffies, stop_retry)) {
+ int gpio_val = !!gpio_get_value(arb->their_gpio);
+
+ if (gpio_val == arb->their_gpio_release) {
+ /* We got it, so return */
+ return 0;
+ }
+
+ usleep_range(50, 200);
+ }
+
+ /* It didn't release, so give up, wait, and try again */
+ gpio_set_value(arb->our_gpio, arb->our_gpio_release);
+
+ usleep_range(arb->wait_retry_us, arb->wait_retry_us * 2);
+ } while (time_before(jiffies, stop_time));
+
+ /* Give up, release our claim */
+ gpio_set_value(arb->our_gpio, arb->our_gpio_release);
+ udelay(arb->slew_delay_us);
+ dev_err(&adap->dev, "Could not claim bus, timeout\n");
+ return -EBUSY;
+}
+
+/**
+ * i2c_arbitrator_deselect - release the I2C bus
+ *
+ * Release the I2C bus using the GPIO-based signalling protocol.
+ */
+static int i2c_arbitrator_deselect(struct i2c_adapter *adap, void *data,
+ u32 chan)
+{
+ const struct i2c_arbitrator_data *arb = data;
+
+ /* Release the bus and wait for the other master to notice */
+ gpio_set_value(arb->our_gpio, arb->our_gpio_release);
+ udelay(arb->slew_delay_us);
+
+ return 0;
+}
+
+static int i2c_arbitrator_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct device_node *parent_np;
+ struct i2c_arbitrator_data *arb;
+ enum of_gpio_flags gpio_flags;
+ unsigned long out_init;
+ int ret;
+
+ /* We only support probing from device tree; no platform_data */
+ if (!np) {
+ dev_err(dev, "Cannot find device tree node\n");
+ return -ENODEV;
+ }
+ if (dev_get_platdata(dev)) {
+ dev_err(dev, "Platform data is not supported\n");
+ return -EINVAL;
+ }
+
+ arb = devm_kzalloc(dev, sizeof(*arb), GFP_KERNEL);
+ if (!arb) {
+ dev_err(dev, "Cannot allocate i2c_arbitrator_data\n");
+ return -ENOMEM;
+ }
+ platform_set_drvdata(pdev, arb);
+
+ /* Request GPIOs */
+ ret = of_get_named_gpio_flags(np, "our-claim-gpio", 0, &gpio_flags);
+ if (!gpio_is_valid(ret)) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Error getting our-claim-gpio\n");
+ return ret;
+ }
+ arb->our_gpio = ret;
+ arb->our_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
+ out_init = (gpio_flags & OF_GPIO_ACTIVE_LOW) ?
+ GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
+ ret = devm_gpio_request_one(dev, arb->our_gpio, out_init,
+ "our-claim-gpio");
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Error requesting our-claim-gpio\n");
+ return ret;
+ }
+
+ ret = of_get_named_gpio_flags(np, "their-claim-gpios", 0, &gpio_flags);
+ if (!gpio_is_valid(ret)) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Error getting their-claim-gpio\n");
+ return ret;
+ }
+ arb->their_gpio = ret;
+ arb->their_gpio_release = !!(gpio_flags & OF_GPIO_ACTIVE_LOW);
+ ret = devm_gpio_request_one(dev, arb->their_gpio, GPIOF_IN,
+ "their-claim-gpio");
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err(dev, "Error requesting their-claim-gpio\n");
+ return ret;
+ }
+
+ /* At the moment we only support a single two master (us + 1 other) */
+ if (gpio_is_valid(of_get_named_gpio(np, "their-claim-gpios", 1))) {
+ dev_err(dev, "Only one other master is supported\n");
+ return -EINVAL;
+ }
+
+ /* Arbitration parameters */
+ if (of_property_read_u32(np, "slew-delay-us", &arb->slew_delay_us))
+ arb->slew_delay_us = 10;
+ if (of_property_read_u32(np, "wait-retry-us", &arb->wait_retry_us))
+ arb->wait_retry_us = 3000;
+ if (of_property_read_u32(np, "wait-free-us", &arb->wait_free_us))
+ arb->wait_free_us = 50000;
+
+ /* Find our parent */
+ parent_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!parent_np) {
+ dev_err(dev, "Cannot parse i2c-parent\n");
+ return -EINVAL;
+ }
+ arb->parent = of_find_i2c_adapter_by_node(parent_np);
+ if (!arb->parent) {
+ dev_err(dev, "Cannot find parent bus\n");
+ return -EPROBE_DEFER;
+ }
+
+ /* Actually add the mux adapter */
+ arb->child = i2c_add_mux_adapter(arb->parent, dev, arb, 0, 0, 0,
+ i2c_arbitrator_select,
+ i2c_arbitrator_deselect);
+ if (!arb->child) {
+ dev_err(dev, "Failed to add adapter\n");
+ ret = -ENODEV;
+ i2c_put_adapter(arb->parent);
+ }
+
+ return ret;
+}
+
+static int i2c_arbitrator_remove(struct platform_device *pdev)
+{
+ struct i2c_arbitrator_data *arb = platform_get_drvdata(pdev);
+
+ i2c_del_mux_adapter(arb->child);
+ i2c_put_adapter(arb->parent);
+
+ return 0;
+}
+
+static const struct of_device_id i2c_arbitrator_of_match[] = {
+ { .compatible = "i2c-arb-gpio-challenge", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_arbitrator_of_match);
+
+static struct platform_driver i2c_arbitrator_driver = {
+ .probe = i2c_arbitrator_probe,
+ .remove = i2c_arbitrator_remove,
+ .driver = {
+ .name = "i2c-arb-gpio-challenge",
+ .of_match_table = i2c_arbitrator_of_match,
+ },
+};
+
+module_platform_driver(i2c_arbitrator_driver);
+
+MODULE_DESCRIPTION("GPIO-based I2C Arbitration");
+MODULE_AUTHOR("Doug Anderson <dianders@chromium.org>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-arb-gpio-challenge");
diff --git a/drivers/i2c/muxes/i2c-mux-gpio.c b/drivers/i2c/muxes/i2c-mux-gpio.c
new file mode 100644
index 000000000..70db99264
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-gpio.c
@@ -0,0 +1,289 @@
+/*
+ * I2C multiplexer using GPIO API
+ *
+ * Peter Korsgaard <peter.korsgaard@barco.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/i2c-mux-gpio.h>
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+
+struct gpiomux {
+ struct i2c_adapter *parent;
+ struct i2c_adapter **adap; /* child busses */
+ struct i2c_mux_gpio_platform_data data;
+ unsigned gpio_base;
+};
+
+static void i2c_mux_gpio_set(const struct gpiomux *mux, unsigned val)
+{
+ int i;
+
+ for (i = 0; i < mux->data.n_gpios; i++)
+ gpio_set_value_cansleep(mux->gpio_base + mux->data.gpios[i],
+ val & (1 << i));
+}
+
+static int i2c_mux_gpio_select(struct i2c_adapter *adap, void *data, u32 chan)
+{
+ struct gpiomux *mux = data;
+
+ i2c_mux_gpio_set(mux, chan);
+
+ return 0;
+}
+
+static int i2c_mux_gpio_deselect(struct i2c_adapter *adap, void *data, u32 chan)
+{
+ struct gpiomux *mux = data;
+
+ i2c_mux_gpio_set(mux, mux->data.idle);
+
+ return 0;
+}
+
+static int match_gpio_chip_by_label(struct gpio_chip *chip,
+ void *data)
+{
+ return !strcmp(chip->label, data);
+}
+
+#ifdef CONFIG_OF
+static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
+ struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct device_node *adapter_np, *child;
+ struct i2c_adapter *adapter;
+ unsigned *values, *gpios;
+ int i = 0, ret;
+
+ if (!np)
+ return -ENODEV;
+
+ adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!adapter_np) {
+ dev_err(&pdev->dev, "Cannot parse i2c-parent\n");
+ return -ENODEV;
+ }
+ adapter = of_find_i2c_adapter_by_node(adapter_np);
+ if (!adapter)
+ return -EPROBE_DEFER;
+
+ mux->data.parent = i2c_adapter_id(adapter);
+ put_device(&adapter->dev);
+
+ mux->data.n_values = of_get_child_count(np);
+
+ values = devm_kzalloc(&pdev->dev,
+ sizeof(*mux->data.values) * mux->data.n_values,
+ GFP_KERNEL);
+ if (!values) {
+ dev_err(&pdev->dev, "Cannot allocate values array");
+ return -ENOMEM;
+ }
+
+ for_each_child_of_node(np, child) {
+ of_property_read_u32(child, "reg", values + i);
+ i++;
+ }
+ mux->data.values = values;
+
+ if (of_property_read_u32(np, "idle-state", &mux->data.idle))
+ mux->data.idle = I2C_MUX_GPIO_NO_IDLE;
+
+ mux->data.n_gpios = of_gpio_named_count(np, "mux-gpios");
+ if (mux->data.n_gpios < 0) {
+ dev_err(&pdev->dev, "Missing mux-gpios property in the DT.\n");
+ return -EINVAL;
+ }
+
+ gpios = devm_kzalloc(&pdev->dev,
+ sizeof(*mux->data.gpios) * mux->data.n_gpios, GFP_KERNEL);
+ if (!gpios) {
+ dev_err(&pdev->dev, "Cannot allocate gpios array");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < mux->data.n_gpios; i++) {
+ ret = of_get_named_gpio(np, "mux-gpios", i);
+ if (ret < 0)
+ return ret;
+ gpios[i] = ret;
+ }
+
+ mux->data.gpios = gpios;
+
+ return 0;
+}
+#else
+static int i2c_mux_gpio_probe_dt(struct gpiomux *mux,
+ struct platform_device *pdev)
+{
+ return 0;
+}
+#endif
+
+static int i2c_mux_gpio_probe(struct platform_device *pdev)
+{
+ struct gpiomux *mux;
+ struct i2c_adapter *parent;
+ int (*deselect) (struct i2c_adapter *, void *, u32);
+ unsigned initial_state, gpio_base;
+ int i, ret;
+
+ mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux) {
+ dev_err(&pdev->dev, "Cannot allocate gpiomux structure");
+ return -ENOMEM;
+ }
+
+ platform_set_drvdata(pdev, mux);
+
+ if (!dev_get_platdata(&pdev->dev)) {
+ ret = i2c_mux_gpio_probe_dt(mux, pdev);
+ if (ret < 0)
+ return ret;
+ } else {
+ memcpy(&mux->data, dev_get_platdata(&pdev->dev),
+ sizeof(mux->data));
+ }
+
+ /*
+ * If a GPIO chip name is provided, the GPIO pin numbers provided are
+ * relative to its base GPIO number. Otherwise they are absolute.
+ */
+ if (mux->data.gpio_chip) {
+ struct gpio_chip *gpio;
+
+ gpio = gpiochip_find(mux->data.gpio_chip,
+ match_gpio_chip_by_label);
+ if (!gpio)
+ return -EPROBE_DEFER;
+
+ gpio_base = gpio->base;
+ } else {
+ gpio_base = 0;
+ }
+
+ parent = i2c_get_adapter(mux->data.parent);
+ if (!parent)
+ return -EPROBE_DEFER;
+
+ mux->parent = parent;
+ mux->gpio_base = gpio_base;
+
+ mux->adap = devm_kzalloc(&pdev->dev,
+ sizeof(*mux->adap) * mux->data.n_values,
+ GFP_KERNEL);
+ if (!mux->adap) {
+ dev_err(&pdev->dev, "Cannot allocate i2c_adapter structure");
+ ret = -ENOMEM;
+ goto alloc_failed;
+ }
+
+ if (mux->data.idle != I2C_MUX_GPIO_NO_IDLE) {
+ initial_state = mux->data.idle;
+ deselect = i2c_mux_gpio_deselect;
+ } else {
+ initial_state = mux->data.values[0];
+ deselect = NULL;
+ }
+
+ for (i = 0; i < mux->data.n_gpios; i++) {
+ ret = gpio_request(gpio_base + mux->data.gpios[i], "i2c-mux-gpio");
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request GPIO %d\n",
+ mux->data.gpios[i]);
+ goto err_request_gpio;
+ }
+
+ ret = gpio_direction_output(gpio_base + mux->data.gpios[i],
+ initial_state & (1 << i));
+ if (ret) {
+ dev_err(&pdev->dev,
+ "Failed to set direction of GPIO %d to output\n",
+ mux->data.gpios[i]);
+ i++; /* gpio_request above succeeded, so must free */
+ goto err_request_gpio;
+ }
+ }
+
+ for (i = 0; i < mux->data.n_values; i++) {
+ u32 nr = mux->data.base_nr ? (mux->data.base_nr + i) : 0;
+ unsigned int class = mux->data.classes ? mux->data.classes[i] : 0;
+
+ mux->adap[i] = i2c_add_mux_adapter(parent, &pdev->dev, mux, nr,
+ mux->data.values[i], class,
+ i2c_mux_gpio_select, deselect);
+ if (!mux->adap[i]) {
+ ret = -ENODEV;
+ dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
+ goto add_adapter_failed;
+ }
+ }
+
+ dev_info(&pdev->dev, "%d port mux on %s adapter\n",
+ mux->data.n_values, parent->name);
+
+ return 0;
+
+add_adapter_failed:
+ for (; i > 0; i--)
+ i2c_del_mux_adapter(mux->adap[i - 1]);
+ i = mux->data.n_gpios;
+err_request_gpio:
+ for (; i > 0; i--)
+ gpio_free(gpio_base + mux->data.gpios[i - 1]);
+alloc_failed:
+ i2c_put_adapter(parent);
+
+ return ret;
+}
+
+static int i2c_mux_gpio_remove(struct platform_device *pdev)
+{
+ struct gpiomux *mux = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < mux->data.n_values; i++)
+ i2c_del_mux_adapter(mux->adap[i]);
+
+ for (i = 0; i < mux->data.n_gpios; i++)
+ gpio_free(mux->gpio_base + mux->data.gpios[i]);
+
+ i2c_put_adapter(mux->parent);
+
+ return 0;
+}
+
+static const struct of_device_id i2c_mux_gpio_of_match[] = {
+ { .compatible = "i2c-mux-gpio", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_gpio_of_match);
+
+static struct platform_driver i2c_mux_gpio_driver = {
+ .probe = i2c_mux_gpio_probe,
+ .remove = i2c_mux_gpio_remove,
+ .driver = {
+ .name = "i2c-mux-gpio",
+ .of_match_table = i2c_mux_gpio_of_match,
+ },
+};
+
+module_platform_driver(i2c_mux_gpio_driver);
+
+MODULE_DESCRIPTION("GPIO-based I2C multiplexer driver");
+MODULE_AUTHOR("Peter Korsgaard <peter.korsgaard@barco.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:i2c-mux-gpio");
diff --git a/drivers/i2c/muxes/i2c-mux-pca9541.c b/drivers/i2c/muxes/i2c-mux-pca9541.c
new file mode 100644
index 000000000..0c8d4d2cb
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-pca9541.c
@@ -0,0 +1,400 @@
+/*
+ * I2C multiplexer driver for PCA9541 bus master selector
+ *
+ * Copyright (c) 2010 Ericsson AB.
+ *
+ * Author: Guenter Roeck <linux@roeck-us.net>
+ *
+ * Derived from:
+ * pca954x.c
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/jiffies.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+
+#include <linux/i2c/pca954x.h>
+
+/*
+ * The PCA9541 is a bus master selector. It supports two I2C masters connected
+ * to a single slave bus.
+ *
+ * Before each bus transaction, a master has to acquire bus ownership. After the
+ * transaction is complete, bus ownership has to be released. This fits well
+ * into the I2C multiplexer framework, which provides select and release
+ * functions for this purpose. For this reason, this driver is modeled as
+ * single-channel I2C bus multiplexer.
+ *
+ * This driver assumes that the two bus masters are controlled by two different
+ * hosts. If a single host controls both masters, platform code has to ensure
+ * that only one of the masters is instantiated at any given time.
+ */
+
+#define PCA9541_CONTROL 0x01
+#define PCA9541_ISTAT 0x02
+
+#define PCA9541_CTL_MYBUS (1 << 0)
+#define PCA9541_CTL_NMYBUS (1 << 1)
+#define PCA9541_CTL_BUSON (1 << 2)
+#define PCA9541_CTL_NBUSON (1 << 3)
+#define PCA9541_CTL_BUSINIT (1 << 4)
+#define PCA9541_CTL_TESTON (1 << 6)
+#define PCA9541_CTL_NTESTON (1 << 7)
+
+#define PCA9541_ISTAT_INTIN (1 << 0)
+#define PCA9541_ISTAT_BUSINIT (1 << 1)
+#define PCA9541_ISTAT_BUSOK (1 << 2)
+#define PCA9541_ISTAT_BUSLOST (1 << 3)
+#define PCA9541_ISTAT_MYTEST (1 << 6)
+#define PCA9541_ISTAT_NMYTEST (1 << 7)
+
+#define BUSON (PCA9541_CTL_BUSON | PCA9541_CTL_NBUSON)
+#define MYBUS (PCA9541_CTL_MYBUS | PCA9541_CTL_NMYBUS)
+#define mybus(x) (!((x) & MYBUS) || ((x) & MYBUS) == MYBUS)
+#define busoff(x) (!((x) & BUSON) || ((x) & BUSON) == BUSON)
+
+/* arbitration timeouts, in jiffies */
+#define ARB_TIMEOUT (HZ / 8) /* 125 ms until forcing bus ownership */
+#define ARB2_TIMEOUT (HZ / 4) /* 250 ms until acquisition failure */
+
+/* arbitration retry delays, in us */
+#define SELECT_DELAY_SHORT 50
+#define SELECT_DELAY_LONG 1000
+
+struct pca9541 {
+ struct i2c_adapter *mux_adap;
+ unsigned long select_timeout;
+ unsigned long arb_timeout;
+};
+
+static const struct i2c_device_id pca9541_id[] = {
+ {"pca9541", 0},
+ {}
+};
+
+MODULE_DEVICE_TABLE(i2c, pca9541_id);
+
+/*
+ * Write to chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
+ * as they will try to lock the adapter a second time.
+ */
+static int pca9541_reg_write(struct i2c_client *client, u8 command, u8 val)
+{
+ struct i2c_adapter *adap = client->adapter;
+ int ret;
+
+ if (adap->algo->master_xfer) {
+ struct i2c_msg msg;
+ char buf[2];
+
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = 2;
+ buf[0] = command;
+ buf[1] = val;
+ msg.buf = buf;
+ ret = __i2c_transfer(adap, &msg, 1);
+ } else {
+ union i2c_smbus_data data;
+
+ data.byte = val;
+ ret = adap->algo->smbus_xfer(adap, client->addr,
+ client->flags,
+ I2C_SMBUS_WRITE,
+ command,
+ I2C_SMBUS_BYTE_DATA, &data);
+ }
+
+ return ret;
+}
+
+/*
+ * Read from chip register. Don't use i2c_transfer()/i2c_smbus_xfer()
+ * as they will try to lock adapter a second time.
+ */
+static int pca9541_reg_read(struct i2c_client *client, u8 command)
+{
+ struct i2c_adapter *adap = client->adapter;
+ int ret;
+ u8 val;
+
+ if (adap->algo->master_xfer) {
+ struct i2c_msg msg[2] = {
+ {
+ .addr = client->addr,
+ .flags = 0,
+ .len = 1,
+ .buf = &command
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = 1,
+ .buf = &val
+ }
+ };
+ ret = __i2c_transfer(adap, msg, 2);
+ if (ret == 2)
+ ret = val;
+ else if (ret >= 0)
+ ret = -EIO;
+ } else {
+ union i2c_smbus_data data;
+
+ ret = adap->algo->smbus_xfer(adap, client->addr,
+ client->flags,
+ I2C_SMBUS_READ,
+ command,
+ I2C_SMBUS_BYTE_DATA, &data);
+ if (!ret)
+ ret = data.byte;
+ }
+ return ret;
+}
+
+/*
+ * Arbitration management functions
+ */
+
+/* Release bus. Also reset NTESTON and BUSINIT if it was set. */
+static void pca9541_release_bus(struct i2c_client *client)
+{
+ int reg;
+
+ reg = pca9541_reg_read(client, PCA9541_CONTROL);
+ if (reg >= 0 && !busoff(reg) && mybus(reg))
+ pca9541_reg_write(client, PCA9541_CONTROL,
+ (reg & PCA9541_CTL_NBUSON) >> 1);
+}
+
+/*
+ * Arbitration is defined as a two-step process. A bus master can only activate
+ * the slave bus if it owns it; otherwise it has to request ownership first.
+ * This multi-step process ensures that access contention is resolved
+ * gracefully.
+ *
+ * Bus Ownership Other master Action
+ * state requested access
+ * ----------------------------------------------------
+ * off - yes wait for arbitration timeout or
+ * for other master to drop request
+ * off no no take ownership
+ * off yes no turn on bus
+ * on yes - done
+ * on no - wait for arbitration timeout or
+ * for other master to release bus
+ *
+ * The main contention point occurs if the slave bus is off and both masters
+ * request ownership at the same time. In this case, one master will turn on
+ * the slave bus, believing that it owns it. The other master will request
+ * bus ownership. Result is that the bus is turned on, and master which did
+ * _not_ own the slave bus before ends up owning it.
+ */
+
+/* Control commands per PCA9541 datasheet */
+static const u8 pca9541_control[16] = {
+ 4, 0, 1, 5, 4, 4, 5, 5, 0, 0, 1, 1, 0, 4, 5, 1
+};
+
+/*
+ * Channel arbitration
+ *
+ * Return values:
+ * <0: error
+ * 0 : bus not acquired
+ * 1 : bus acquired
+ */
+static int pca9541_arbitrate(struct i2c_client *client)
+{
+ struct pca9541 *data = i2c_get_clientdata(client);
+ int reg;
+
+ reg = pca9541_reg_read(client, PCA9541_CONTROL);
+ if (reg < 0)
+ return reg;
+
+ if (busoff(reg)) {
+ int istat;
+ /*
+ * Bus is off. Request ownership or turn it on unless
+ * other master requested ownership.
+ */
+ istat = pca9541_reg_read(client, PCA9541_ISTAT);
+ if (!(istat & PCA9541_ISTAT_NMYTEST)
+ || time_is_before_eq_jiffies(data->arb_timeout)) {
+ /*
+ * Other master did not request ownership,
+ * or arbitration timeout expired. Take the bus.
+ */
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ pca9541_control[reg & 0x0f]
+ | PCA9541_CTL_NTESTON);
+ data->select_timeout = SELECT_DELAY_SHORT;
+ } else {
+ /*
+ * Other master requested ownership.
+ * Set extra long timeout to give it time to acquire it.
+ */
+ data->select_timeout = SELECT_DELAY_LONG * 2;
+ }
+ } else if (mybus(reg)) {
+ /*
+ * Bus is on, and we own it. We are done with acquisition.
+ * Reset NTESTON and BUSINIT, then return success.
+ */
+ if (reg & (PCA9541_CTL_NTESTON | PCA9541_CTL_BUSINIT))
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ reg & ~(PCA9541_CTL_NTESTON
+ | PCA9541_CTL_BUSINIT));
+ return 1;
+ } else {
+ /*
+ * Other master owns the bus.
+ * If arbitration timeout has expired, force ownership.
+ * Otherwise request it.
+ */
+ data->select_timeout = SELECT_DELAY_LONG;
+ if (time_is_before_eq_jiffies(data->arb_timeout)) {
+ /* Time is up, take the bus and reset it. */
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ pca9541_control[reg & 0x0f]
+ | PCA9541_CTL_BUSINIT
+ | PCA9541_CTL_NTESTON);
+ } else {
+ /* Request bus ownership if needed */
+ if (!(reg & PCA9541_CTL_NTESTON))
+ pca9541_reg_write(client,
+ PCA9541_CONTROL,
+ reg | PCA9541_CTL_NTESTON);
+ }
+ }
+ return 0;
+}
+
+static int pca9541_select_chan(struct i2c_adapter *adap, void *client, u32 chan)
+{
+ struct pca9541 *data = i2c_get_clientdata(client);
+ int ret;
+ unsigned long timeout = jiffies + ARB2_TIMEOUT;
+ /* give up after this time */
+
+ data->arb_timeout = jiffies + ARB_TIMEOUT;
+ /* force bus ownership after this time */
+
+ do {
+ ret = pca9541_arbitrate(client);
+ if (ret)
+ return ret < 0 ? ret : 0;
+
+ if (data->select_timeout == SELECT_DELAY_SHORT)
+ udelay(data->select_timeout);
+ else
+ msleep(data->select_timeout / 1000);
+ } while (time_is_after_eq_jiffies(timeout));
+
+ return -ETIMEDOUT;
+}
+
+static int pca9541_release_chan(struct i2c_adapter *adap,
+ void *client, u32 chan)
+{
+ pca9541_release_bus(client);
+ return 0;
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+static int pca9541_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adap = client->adapter;
+ struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
+ struct pca9541 *data;
+ int force;
+ int ret = -ENODEV;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE_DATA))
+ goto err;
+
+ data = kzalloc(sizeof(struct pca9541), GFP_KERNEL);
+ if (!data) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ i2c_set_clientdata(client, data);
+
+ /*
+ * I2C accesses are unprotected here.
+ * We have to lock the adapter before releasing the bus.
+ */
+ i2c_lock_adapter(adap);
+ pca9541_release_bus(client);
+ i2c_unlock_adapter(adap);
+
+ /* Create mux adapter */
+
+ force = 0;
+ if (pdata)
+ force = pdata->modes[0].adap_id;
+ data->mux_adap = i2c_add_mux_adapter(adap, &client->dev, client,
+ force, 0, 0,
+ pca9541_select_chan,
+ pca9541_release_chan);
+
+ if (data->mux_adap == NULL) {
+ dev_err(&client->dev, "failed to register master selector\n");
+ goto exit_free;
+ }
+
+ dev_info(&client->dev, "registered master selector for I2C %s\n",
+ client->name);
+
+ return 0;
+
+exit_free:
+ kfree(data);
+err:
+ return ret;
+}
+
+static int pca9541_remove(struct i2c_client *client)
+{
+ struct pca9541 *data = i2c_get_clientdata(client);
+
+ i2c_del_mux_adapter(data->mux_adap);
+
+ kfree(data);
+ return 0;
+}
+
+static struct i2c_driver pca9541_driver = {
+ .driver = {
+ .name = "pca9541",
+ .owner = THIS_MODULE,
+ },
+ .probe = pca9541_probe,
+ .remove = pca9541_remove,
+ .id_table = pca9541_id,
+};
+
+module_i2c_driver(pca9541_driver);
+
+MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
+MODULE_DESCRIPTION("PCA9541 I2C master selector driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
new file mode 100644
index 000000000..ea4aa9dfc
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
@@ -0,0 +1,314 @@
+/*
+ * I2C multiplexer
+ *
+ * Copyright (c) 2008-2009 Rodolfo Giometti <giometti@linux.it>
+ * Copyright (c) 2008-2009 Eurotech S.p.A. <info@eurotech.it>
+ *
+ * This module supports the PCA954x series of I2C multiplexer/switch chips
+ * made by Philips Semiconductors.
+ * This includes the:
+ * PCA9540, PCA9542, PCA9543, PCA9544, PCA9545, PCA9546, PCA9547
+ * and PCA9548.
+ *
+ * These chips are all controlled via the I2C bus itself, and all have a
+ * single 8-bit register. The upstream "parent" bus fans out to two,
+ * four, or eight downstream busses or channels; which of these
+ * are selected is determined by the chip type and register contents. A
+ * mux can select only one sub-bus at a time; a switch can select any
+ * combination simultaneously.
+ *
+ * Based on:
+ * pca954x.c from Kumar Gala <galak@kernel.crashing.org>
+ * Copyright (C) 2006
+ *
+ * Based on:
+ * pca954x.c from Ken Harrenstien
+ * Copyright (C) 2004 Google, Inc. (Ken Harrenstien)
+ *
+ * Based on:
+ * i2c-virtual_cb.c from Brian Kuschak <bkuschak@yahoo.com>
+ * and
+ * pca9540.c from Jean Delvare <jdelvare@suse.de>.
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/i2c/pca954x.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/pm.h>
+#include <linux/slab.h>
+
+#define PCA954X_MAX_NCHANS 8
+
+enum pca_type {
+ pca_9540,
+ pca_9542,
+ pca_9543,
+ pca_9544,
+ pca_9545,
+ pca_9546,
+ pca_9547,
+ pca_9548,
+};
+
+struct pca954x {
+ enum pca_type type;
+ struct i2c_adapter *virt_adaps[PCA954X_MAX_NCHANS];
+
+ u8 last_chan; /* last register value */
+};
+
+struct chip_desc {
+ u8 nchans;
+ u8 enable; /* used for muxes only */
+ enum muxtype {
+ pca954x_ismux = 0,
+ pca954x_isswi
+ } muxtype;
+};
+
+/* Provide specs for the PCA954x types we know about */
+static const struct chip_desc chips[] = {
+ [pca_9540] = {
+ .nchans = 2,
+ .enable = 0x4,
+ .muxtype = pca954x_ismux,
+ },
+ [pca_9543] = {
+ .nchans = 2,
+ .muxtype = pca954x_isswi,
+ },
+ [pca_9544] = {
+ .nchans = 4,
+ .enable = 0x4,
+ .muxtype = pca954x_ismux,
+ },
+ [pca_9545] = {
+ .nchans = 4,
+ .muxtype = pca954x_isswi,
+ },
+ [pca_9547] = {
+ .nchans = 8,
+ .enable = 0x8,
+ .muxtype = pca954x_ismux,
+ },
+ [pca_9548] = {
+ .nchans = 8,
+ .muxtype = pca954x_isswi,
+ },
+};
+
+static const struct i2c_device_id pca954x_id[] = {
+ { "pca9540", pca_9540 },
+ { "pca9542", pca_9540 },
+ { "pca9543", pca_9543 },
+ { "pca9544", pca_9544 },
+ { "pca9545", pca_9545 },
+ { "pca9546", pca_9545 },
+ { "pca9547", pca_9547 },
+ { "pca9548", pca_9548 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pca954x_id);
+
+/* Write to mux register. Don't use i2c_transfer()/i2c_smbus_xfer()
+ for this as they will try to lock adapter a second time */
+static int pca954x_reg_write(struct i2c_adapter *adap,
+ struct i2c_client *client, u8 val)
+{
+ int ret = -ENODEV;
+
+ if (adap->algo->master_xfer) {
+ struct i2c_msg msg;
+ char buf[1];
+
+ msg.addr = client->addr;
+ msg.flags = 0;
+ msg.len = 1;
+ buf[0] = val;
+ msg.buf = buf;
+ ret = __i2c_transfer(adap, &msg, 1);
+ } else {
+ union i2c_smbus_data data;
+ ret = adap->algo->smbus_xfer(adap, client->addr,
+ client->flags,
+ I2C_SMBUS_WRITE,
+ val, I2C_SMBUS_BYTE, &data);
+ }
+
+ return ret;
+}
+
+static int pca954x_select_chan(struct i2c_adapter *adap,
+ void *client, u32 chan)
+{
+ struct pca954x *data = i2c_get_clientdata(client);
+ const struct chip_desc *chip = &chips[data->type];
+ u8 regval;
+ int ret = 0;
+
+ /* we make switches look like muxes, not sure how to be smarter */
+ if (chip->muxtype == pca954x_ismux)
+ regval = chan | chip->enable;
+ else
+ regval = 1 << chan;
+
+ /* Only select the channel if its different from the last channel */
+ if (data->last_chan != regval) {
+ ret = pca954x_reg_write(adap, client, regval);
+ data->last_chan = regval;
+ }
+
+ return ret;
+}
+
+static int pca954x_deselect_mux(struct i2c_adapter *adap,
+ void *client, u32 chan)
+{
+ struct pca954x *data = i2c_get_clientdata(client);
+
+ /* Deselect active channel */
+ data->last_chan = 0;
+ return pca954x_reg_write(adap, client, data->last_chan);
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+static int pca954x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adap = to_i2c_adapter(client->dev.parent);
+ struct pca954x_platform_data *pdata = dev_get_platdata(&client->dev);
+ struct device_node *of_node = client->dev.of_node;
+ bool idle_disconnect_dt;
+ struct gpio_desc *gpio;
+ int num, force, class;
+ struct pca954x *data;
+ int ret;
+
+ if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_BYTE))
+ return -ENODEV;
+
+ data = devm_kzalloc(&client->dev, sizeof(struct pca954x), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, data);
+
+ /* Get the mux out of reset if a reset GPIO is specified. */
+ gpio = devm_gpiod_get_optional(&client->dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(gpio))
+ return PTR_ERR(gpio);
+
+ /* Write the mux register at addr to verify
+ * that the mux is in fact present. This also
+ * initializes the mux to disconnected state.
+ */
+ if (i2c_smbus_write_byte(client, 0) < 0) {
+ dev_warn(&client->dev, "probe failed\n");
+ return -ENODEV;
+ }
+
+ data->type = id->driver_data;
+ data->last_chan = 0; /* force the first selection */
+
+ idle_disconnect_dt = of_node &&
+ of_property_read_bool(of_node, "i2c-mux-idle-disconnect");
+
+ /* Now create an adapter for each channel */
+ for (num = 0; num < chips[data->type].nchans; num++) {
+ bool idle_disconnect_pd = false;
+
+ force = 0; /* dynamic adap number */
+ class = 0; /* no class by default */
+ if (pdata) {
+ if (num < pdata->num_modes) {
+ /* force static number */
+ force = pdata->modes[num].adap_id;
+ class = pdata->modes[num].class;
+ } else
+ /* discard unconfigured channels */
+ break;
+ idle_disconnect_pd = pdata->modes[num].deselect_on_exit;
+ }
+
+ data->virt_adaps[num] =
+ i2c_add_mux_adapter(adap, &client->dev, client,
+ force, num, class, pca954x_select_chan,
+ (idle_disconnect_pd || idle_disconnect_dt)
+ ? pca954x_deselect_mux : NULL);
+
+ if (data->virt_adaps[num] == NULL) {
+ ret = -ENODEV;
+ dev_err(&client->dev,
+ "failed to register multiplexed adapter"
+ " %d as bus %d\n", num, force);
+ goto virt_reg_failed;
+ }
+ }
+
+ dev_info(&client->dev,
+ "registered %d multiplexed busses for I2C %s %s\n",
+ num, chips[data->type].muxtype == pca954x_ismux
+ ? "mux" : "switch", client->name);
+
+ return 0;
+
+virt_reg_failed:
+ for (num--; num >= 0; num--)
+ i2c_del_mux_adapter(data->virt_adaps[num]);
+ return ret;
+}
+
+static int pca954x_remove(struct i2c_client *client)
+{
+ struct pca954x *data = i2c_get_clientdata(client);
+ const struct chip_desc *chip = &chips[data->type];
+ int i;
+
+ for (i = 0; i < chip->nchans; ++i)
+ if (data->virt_adaps[i]) {
+ i2c_del_mux_adapter(data->virt_adaps[i]);
+ data->virt_adaps[i] = NULL;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pca954x_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct pca954x *data = i2c_get_clientdata(client);
+
+ data->last_chan = 0;
+ return i2c_smbus_write_byte(client, 0);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pca954x_pm, NULL, pca954x_resume);
+
+static struct i2c_driver pca954x_driver = {
+ .driver = {
+ .name = "pca954x",
+ .pm = &pca954x_pm,
+ .owner = THIS_MODULE,
+ },
+ .probe = pca954x_probe,
+ .remove = pca954x_remove,
+ .id_table = pca954x_id,
+};
+
+module_i2c_driver(pca954x_driver);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
+MODULE_DESCRIPTION("PCA954x I2C mux/switch driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/i2c/muxes/i2c-mux-pinctrl.c b/drivers/i2c/muxes/i2c-mux-pinctrl.c
new file mode 100644
index 000000000..b48378c4b
--- /dev/null
+++ b/drivers/i2c/muxes/i2c-mux-pinctrl.c
@@ -0,0 +1,277 @@
+/*
+ * I2C multiplexer using pinctrl API
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/i2c.h>
+#include <linux/i2c-mux.h>
+#include <linux/module.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/i2c-mux-pinctrl.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+struct i2c_mux_pinctrl {
+ struct device *dev;
+ struct i2c_mux_pinctrl_platform_data *pdata;
+ struct pinctrl *pinctrl;
+ struct pinctrl_state **states;
+ struct pinctrl_state *state_idle;
+ struct i2c_adapter *parent;
+ struct i2c_adapter **busses;
+};
+
+static int i2c_mux_pinctrl_select(struct i2c_adapter *adap, void *data,
+ u32 chan)
+{
+ struct i2c_mux_pinctrl *mux = data;
+
+ return pinctrl_select_state(mux->pinctrl, mux->states[chan]);
+}
+
+static int i2c_mux_pinctrl_deselect(struct i2c_adapter *adap, void *data,
+ u32 chan)
+{
+ struct i2c_mux_pinctrl *mux = data;
+
+ return pinctrl_select_state(mux->pinctrl, mux->state_idle);
+}
+
+#ifdef CONFIG_OF
+static int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux,
+ struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ int num_names, i, ret;
+ struct device_node *adapter_np;
+ struct i2c_adapter *adapter;
+
+ if (!np)
+ return 0;
+
+ mux->pdata = devm_kzalloc(&pdev->dev, sizeof(*mux->pdata), GFP_KERNEL);
+ if (!mux->pdata) {
+ dev_err(mux->dev,
+ "Cannot allocate i2c_mux_pinctrl_platform_data\n");
+ return -ENOMEM;
+ }
+
+ num_names = of_property_count_strings(np, "pinctrl-names");
+ if (num_names < 0) {
+ dev_err(mux->dev, "Cannot parse pinctrl-names: %d\n",
+ num_names);
+ return num_names;
+ }
+
+ mux->pdata->pinctrl_states = devm_kzalloc(&pdev->dev,
+ sizeof(*mux->pdata->pinctrl_states) * num_names,
+ GFP_KERNEL);
+ if (!mux->pdata->pinctrl_states) {
+ dev_err(mux->dev, "Cannot allocate pinctrl_states\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < num_names; i++) {
+ ret = of_property_read_string_index(np, "pinctrl-names", i,
+ &mux->pdata->pinctrl_states[mux->pdata->bus_count]);
+ if (ret < 0) {
+ dev_err(mux->dev, "Cannot parse pinctrl-names: %d\n",
+ ret);
+ return ret;
+ }
+ if (!strcmp(mux->pdata->pinctrl_states[mux->pdata->bus_count],
+ "idle")) {
+ if (i != num_names - 1) {
+ dev_err(mux->dev, "idle state must be last\n");
+ return -EINVAL;
+ }
+ mux->pdata->pinctrl_state_idle = "idle";
+ } else {
+ mux->pdata->bus_count++;
+ }
+ }
+
+ adapter_np = of_parse_phandle(np, "i2c-parent", 0);
+ if (!adapter_np) {
+ dev_err(mux->dev, "Cannot parse i2c-parent\n");
+ return -ENODEV;
+ }
+ adapter = of_find_i2c_adapter_by_node(adapter_np);
+ if (!adapter) {
+ dev_err(mux->dev, "Cannot find parent bus\n");
+ return -EPROBE_DEFER;
+ }
+ mux->pdata->parent_bus_num = i2c_adapter_id(adapter);
+ put_device(&adapter->dev);
+
+ return 0;
+}
+#else
+static inline int i2c_mux_pinctrl_parse_dt(struct i2c_mux_pinctrl *mux,
+ struct platform_device *pdev)
+{
+ return 0;
+}
+#endif
+
+static int i2c_mux_pinctrl_probe(struct platform_device *pdev)
+{
+ struct i2c_mux_pinctrl *mux;
+ int (*deselect)(struct i2c_adapter *, void *, u32);
+ int i, ret;
+
+ mux = devm_kzalloc(&pdev->dev, sizeof(*mux), GFP_KERNEL);
+ if (!mux) {
+ dev_err(&pdev->dev, "Cannot allocate i2c_mux_pinctrl\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+ platform_set_drvdata(pdev, mux);
+
+ mux->dev = &pdev->dev;
+
+ mux->pdata = dev_get_platdata(&pdev->dev);
+ if (!mux->pdata) {
+ ret = i2c_mux_pinctrl_parse_dt(mux, pdev);
+ if (ret < 0)
+ goto err;
+ }
+ if (!mux->pdata) {
+ dev_err(&pdev->dev, "Missing platform data\n");
+ ret = -ENODEV;
+ goto err;
+ }
+
+ mux->states = devm_kzalloc(&pdev->dev,
+ sizeof(*mux->states) * mux->pdata->bus_count,
+ GFP_KERNEL);
+ if (!mux->states) {
+ dev_err(&pdev->dev, "Cannot allocate states\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ mux->busses = devm_kzalloc(&pdev->dev,
+ sizeof(*mux->busses) * mux->pdata->bus_count,
+ GFP_KERNEL);
+ if (!mux->busses) {
+ dev_err(&pdev->dev, "Cannot allocate busses\n");
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ mux->pinctrl = devm_pinctrl_get(&pdev->dev);
+ if (IS_ERR(mux->pinctrl)) {
+ ret = PTR_ERR(mux->pinctrl);
+ dev_err(&pdev->dev, "Cannot get pinctrl: %d\n", ret);
+ goto err;
+ }
+ for (i = 0; i < mux->pdata->bus_count; i++) {
+ mux->states[i] = pinctrl_lookup_state(mux->pinctrl,
+ mux->pdata->pinctrl_states[i]);
+ if (IS_ERR(mux->states[i])) {
+ ret = PTR_ERR(mux->states[i]);
+ dev_err(&pdev->dev,
+ "Cannot look up pinctrl state %s: %d\n",
+ mux->pdata->pinctrl_states[i], ret);
+ goto err;
+ }
+ }
+ if (mux->pdata->pinctrl_state_idle) {
+ mux->state_idle = pinctrl_lookup_state(mux->pinctrl,
+ mux->pdata->pinctrl_state_idle);
+ if (IS_ERR(mux->state_idle)) {
+ ret = PTR_ERR(mux->state_idle);
+ dev_err(&pdev->dev,
+ "Cannot look up pinctrl state %s: %d\n",
+ mux->pdata->pinctrl_state_idle, ret);
+ goto err;
+ }
+
+ deselect = i2c_mux_pinctrl_deselect;
+ } else {
+ deselect = NULL;
+ }
+
+ mux->parent = i2c_get_adapter(mux->pdata->parent_bus_num);
+ if (!mux->parent) {
+ dev_err(&pdev->dev, "Parent adapter (%d) not found\n",
+ mux->pdata->parent_bus_num);
+ ret = -EPROBE_DEFER;
+ goto err;
+ }
+
+ for (i = 0; i < mux->pdata->bus_count; i++) {
+ u32 bus = mux->pdata->base_bus_num ?
+ (mux->pdata->base_bus_num + i) : 0;
+
+ mux->busses[i] = i2c_add_mux_adapter(mux->parent, &pdev->dev,
+ mux, bus, i, 0,
+ i2c_mux_pinctrl_select,
+ deselect);
+ if (!mux->busses[i]) {
+ ret = -ENODEV;
+ dev_err(&pdev->dev, "Failed to add adapter %d\n", i);
+ goto err_del_adapter;
+ }
+ }
+
+ return 0;
+
+err_del_adapter:
+ for (; i > 0; i--)
+ i2c_del_mux_adapter(mux->busses[i - 1]);
+ i2c_put_adapter(mux->parent);
+err:
+ return ret;
+}
+
+static int i2c_mux_pinctrl_remove(struct platform_device *pdev)
+{
+ struct i2c_mux_pinctrl *mux = platform_get_drvdata(pdev);
+ int i;
+
+ for (i = 0; i < mux->pdata->bus_count; i++)
+ i2c_del_mux_adapter(mux->busses[i]);
+
+ i2c_put_adapter(mux->parent);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id i2c_mux_pinctrl_of_match[] = {
+ { .compatible = "i2c-mux-pinctrl", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, i2c_mux_pinctrl_of_match);
+#endif
+
+static struct platform_driver i2c_mux_pinctrl_driver = {
+ .driver = {
+ .name = "i2c-mux-pinctrl",
+ .of_match_table = of_match_ptr(i2c_mux_pinctrl_of_match),
+ },
+ .probe = i2c_mux_pinctrl_probe,
+ .remove = i2c_mux_pinctrl_remove,
+};
+module_platform_driver(i2c_mux_pinctrl_driver);
+
+MODULE_DESCRIPTION("pinctrl-based I2C multiplexer driver");
+MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:i2c-mux-pinctrl");
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-12-01 03:23:08 +0000