From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/i2c/muxes/Kconfig | 63 +++++ drivers/i2c/muxes/Makefile | 11 + drivers/i2c/muxes/i2c-arb-gpio-challenge.c | 248 ++++++++++++++++++ drivers/i2c/muxes/i2c-mux-gpio.c | 289 +++++++++++++++++++++ drivers/i2c/muxes/i2c-mux-pca9541.c | 400 +++++++++++++++++++++++++++++ drivers/i2c/muxes/i2c-mux-pca954x.c | 314 ++++++++++++++++++++++ drivers/i2c/muxes/i2c-mux-pinctrl.c | 277 ++++++++++++++++++++ 7 files changed, 1602 insertions(+) create mode 100644 drivers/i2c/muxes/Kconfig create mode 100644 drivers/i2c/muxes/Makefile create mode 100644 drivers/i2c/muxes/i2c-arb-gpio-challenge.c create mode 100644 drivers/i2c/muxes/i2c-mux-gpio.c create mode 100644 drivers/i2c/muxes/i2c-mux-pca9541.c create mode 100644 drivers/i2c/muxes/i2c-mux-pca954x.c create mode 100644 drivers/i2c/muxes/i2c-mux-pinctrl.c (limited to 'drivers/i2c/muxes') 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 +#include +#include +#include +#include +#include +#include +#include +#include + + +/** + * 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 "); +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 + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +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 "); +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 + * + * Derived from: + * pca954x.c + * + * Copyright (c) 2008-2009 Rodolfo Giometti + * Copyright (c) 2008-2009 Eurotech S.p.A. + * + * 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 +#include +#include +#include +#include +#include +#include + +#include + +/* + * 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 "); +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 + * Copyright (c) 2008-2009 Eurotech S.p.A. + * + * 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 + * 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 + * and + * pca9540.c from Jean Delvare . + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include + +#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 "); +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 . + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +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 "); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:i2c-mux-pinctrl"); -- cgit v1.2.3-54-g00ecf