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Subject[PATCH] gpio: enable expander pca957x
Date
Support both PCA9574(8-bit) and PCA9575(16-bit) gpio expander.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
---
drivers/gpio/Kconfig | 14 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/pca957x.c | 491 +++++++++++++++++++++++++++++++++++++++++++
include/linux/i2c/pca957x.h | 28 +++
4 files changed, 534 insertions(+), 0 deletions(-)
create mode 100644 drivers/gpio/pca957x.c
create mode 100644 include/linux/i2c/pca957x.h

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 7ef9108..28be09a 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -191,6 +191,20 @@ config GPIO_PCA953X_IRQ
Say yes here to enable the pca953x to be used as an interrupt
controller. It requires the driver to be built in the kernel.

+config GPIO_PCA957X
+ tristate "PCA957x I/O ports"
+ depends on I2C
+ help
+ Say yes here to provide access several register-oriented
+ SMBus I/O expanders. Compatible models include:
+
+ 8 bits: pca9574
+
+ 16 bits: pca9575
+
+ This driver can also be built as a module. If so, the module
+ will be called pca957x
+
config GPIO_PCF857X
tristate "PCF857x, PCA{85,96}7x, and MAX732[89] I2C GPIO expanders"
depends on I2C
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 3351cf8..6d941bd 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_GPIO_MC33880) += mc33880.o
obj-$(CONFIG_GPIO_MCP23S08) += mcp23s08.o
obj-$(CONFIG_GPIO_74X164) += 74x164.o
obj-$(CONFIG_GPIO_PCA953X) += pca953x.o
+obj-$(CONFIG_GPIO_PCA957X) += pca957x.o
obj-$(CONFIG_GPIO_PCF857X) += pcf857x.o
obj-$(CONFIG_GPIO_PCH) += pch_gpio.o
obj-$(CONFIG_GPIO_PL061) += pl061.o
diff --git a/drivers/gpio/pca957x.c b/drivers/gpio/pca957x.c
new file mode 100644
index 0000000..9d8ceb1
--- /dev/null
+++ b/drivers/gpio/pca957x.c
@@ -0,0 +1,491 @@
+/*
+ * pca957x.c - 8/16 bit I/O ports
+ *
+ * Copyright (C) 2005 Ben Gardner <bgardner@wabtec.com>
+ * Copyright (C) 2007 Marvell International Ltd.
+ *
+ * Derived from drivers/i2c/chips/pca9539.c
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/i2c/pca957x.h>
+
+#define PCA957X_IN 0
+#define PCA957X_INVRT 1
+#define PCA957X_BKEN 2
+#define PCA957X_PUPD 3
+#define PCA957X_CFG 4
+#define PCA957X_OUT 5
+#define PCA957X_MSK 6
+#define PCA957X_INTS 7
+
+static const struct i2c_device_id pca957x_id[] = {
+ { "pca9574", 8, },
+ { "pca9575", 16, },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, pca957x_id);
+
+struct pca957x_chip {
+ unsigned gpio_start;
+ uint16_t reg_output;
+ uint16_t reg_direction;
+
+ struct i2c_client *client;
+ struct gpio_chip gpio_chip;
+ struct mutex irq_lock;
+ uint16_t irq_mask;
+ uint16_t irq_stat;
+ uint16_t irq_trig_raise;
+ uint16_t irq_trig_fall;
+ int irq_base;
+};
+
+static int pca957x_read_reg(struct pca957x_chip *chip, int reg, uint16_t *val)
+{
+ int ret;
+
+ if (chip->gpio_chip.ngpio <= 8)
+ ret = i2c_smbus_read_byte_data(chip->client, reg);
+ else
+ ret = i2c_smbus_read_word_data(chip->client, reg << 1);
+
+ if (ret < 0) {
+ dev_err(&chip->client->dev, "failed reading register\n");
+ return ret;
+ }
+
+ *val = (uint16_t)ret;
+ return 0;
+}
+
+static int pca957x_write_reg(struct pca957x_chip *chip, int reg, uint16_t val)
+{
+ int ret;
+
+ if (chip->gpio_chip.ngpio <= 8)
+ ret = i2c_smbus_write_byte_data(chip->client, reg, val);
+ else {
+ ret = i2c_smbus_write_byte_data(chip->client, reg << 1,
+ val & 0xff);
+ if (!ret) {
+ ret = i2c_smbus_write_byte_data(chip->client,
+ (reg << 1) + 1,
+ (val & 0xff00) >> 8);
+ }
+ }
+
+ if (ret < 0) {
+ dev_err(&chip->client->dev, "failed writing register\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int pca957x_gpio_direction_input(struct gpio_chip *gc, unsigned off)
+{
+ struct pca957x_chip *chip;
+ uint16_t reg_val;
+ int ret;
+
+ chip = container_of(gc, struct pca957x_chip, gpio_chip);
+
+ reg_val = chip->reg_direction | (1u << off);
+ ret = pca957x_write_reg(chip, PCA957X_CFG, reg_val);
+ if (ret)
+ return ret;
+
+ chip->reg_direction = reg_val;
+ return 0;
+}
+
+static int pca957x_gpio_direction_output(struct gpio_chip *gc,
+ unsigned off, int val)
+{
+ struct pca957x_chip *chip;
+ uint16_t reg_val;
+ int ret;
+
+ chip = container_of(gc, struct pca957x_chip, gpio_chip);
+
+ /* set output level */
+ if (val)
+ reg_val = chip->reg_output | (1u << off);
+ else
+ reg_val = chip->reg_output & ~(1u << off);
+
+ ret = pca957x_write_reg(chip, PCA957X_OUT, reg_val);
+ if (ret)
+ return ret;
+
+ chip->reg_output = reg_val;
+
+ /* then direction */
+ reg_val = chip->reg_direction & ~(1u << off);
+ ret = pca957x_write_reg(chip, PCA957X_CFG, reg_val);
+ if (ret)
+ return ret;
+
+ chip->reg_direction = reg_val;
+ return 0;
+}
+
+static int pca957x_gpio_get_value(struct gpio_chip *gc, unsigned off)
+{
+ struct pca957x_chip *chip;
+ uint16_t reg_val;
+ int ret;
+
+ chip = container_of(gc, struct pca957x_chip, gpio_chip);
+
+ ret = pca957x_read_reg(chip, PCA957X_IN, &reg_val);
+ if (ret < 0) {
+ /*
+ * NOTE: diagnostic already emitted; that's all we should
+ * do unless gpio_*_value_cansleep() calls become different
+ * from their nonsleeping siblings (and report faults).
+ */
+ return 0;
+ }
+
+ return (reg_val & (1u << off)) ? 1 : 0;
+}
+
+static void pca957x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
+{
+ struct pca957x_chip *chip;
+ uint16_t reg_val;
+ int ret;
+
+ chip = container_of(gc, struct pca957x_chip, gpio_chip);
+
+ if (val)
+ reg_val = chip->reg_output | (1u << off);
+ else
+ reg_val = chip->reg_output & ~(1u << off);
+
+ ret = pca957x_write_reg(chip, PCA957X_OUT, reg_val);
+ if (ret)
+ return;
+
+ chip->reg_output = reg_val;
+}
+
+static void pca957x_setup_gpio(struct pca957x_chip *chip, int gpios)
+{
+ struct gpio_chip *gc;
+
+ gc = &chip->gpio_chip;
+
+ gc->direction_input = pca957x_gpio_direction_input;
+ gc->direction_output = pca957x_gpio_direction_output;
+ gc->get = pca957x_gpio_get_value;
+ gc->set = pca957x_gpio_set_value;
+ gc->can_sleep = 1;
+
+ gc->base = chip->gpio_start;
+ gc->ngpio = gpios;
+ gc->label = chip->client->name;
+ gc->dev = &chip->client->dev;
+ gc->owner = THIS_MODULE;
+}
+
+static int pca957x_gpio_to_irq(struct gpio_chip *gc, unsigned off)
+{
+ struct pca957x_chip *chip;
+
+ chip = container_of(gc, struct pca957x_chip, gpio_chip);
+ return chip->irq_base + off;
+}
+
+static void pca957x_irq_mask(struct irq_data *d)
+{
+ struct pca957x_chip *chip = irq_data_get_irq_chip_data(d);
+
+ chip->irq_mask &= ~(1 << (d->irq - chip->irq_base));
+}
+
+static void pca957x_irq_unmask(struct irq_data *d)
+{
+ struct pca957x_chip *chip = irq_data_get_irq_chip_data(d);
+
+ chip->irq_mask |= 1 << (d->irq - chip->irq_base);
+}
+
+static void pca957x_irq_bus_lock(struct irq_data *d)
+{
+ struct pca957x_chip *chip = irq_data_get_irq_chip_data(d);
+
+ mutex_lock(&chip->irq_lock);
+}
+
+static void pca957x_irq_bus_sync_unlock(struct irq_data *d)
+{
+ struct pca957x_chip *chip = irq_data_get_irq_chip_data(d);
+
+ mutex_unlock(&chip->irq_lock);
+}
+
+static int pca957x_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct pca957x_chip *chip = irq_data_get_irq_chip_data(d);
+ uint16_t mask = 1u << (d->irq - chip->irq_base);
+
+ if (!(type & IRQ_TYPE_EDGE_BOTH)) {
+ dev_err(&chip->client->dev, "irq %d: unsupported type %d\n",
+ d->irq, type);
+ return -EINVAL;
+ }
+
+ if (type & IRQ_TYPE_EDGE_RISING)
+ chip->irq_trig_raise |= mask;
+ else
+ chip->irq_trig_raise &= ~mask;
+
+ if (type & IRQ_TYPE_EDGE_FALLING)
+ chip->irq_trig_fall |= mask;
+ else
+ chip->irq_trig_fall &= ~mask;
+
+ return 0;
+}
+
+static struct irq_chip pca957x_irq_chip = {
+ .name = "pca957x",
+ .irq_mask = pca957x_irq_mask,
+ .irq_unmask = pca957x_irq_unmask,
+ .irq_bus_lock = pca957x_irq_bus_lock,
+ .irq_bus_sync_unlock = pca957x_irq_bus_sync_unlock,
+ .irq_set_type = pca957x_irq_set_type,
+};
+
+static irqreturn_t pca957x_irq_handler(int irq, void *devid)
+{
+ struct pca957x_chip *chip = devid;
+ uint16_t old_in, new_in, pending, level, trigger;
+ int ret;
+
+ ret = pca957x_read_reg(chip, PCA957X_IN, &new_in);
+ if (ret)
+ goto out;
+
+ new_in &= chip->reg_direction;
+ old_in = chip->irq_stat;
+ trigger = (new_in ^ old_in) & chip->irq_mask;
+ if (!trigger)
+ goto out;
+
+ chip->irq_stat = new_in;
+ pending = (old_in & chip->irq_trig_fall)
+ | (new_in & chip->irq_trig_raise);
+ pending &= trigger;
+
+ do {
+ level = __ffs(pending);
+ generic_handle_irq(level + chip->irq_base);
+
+ pending &= ~(1 << level);
+ } while (pending);
+out:
+ return IRQ_HANDLED;
+}
+
+static int pca957x_init_irq(struct pca957x_chip *chip)
+{
+ struct i2c_client *client = chip->client;
+ struct pca957x_platform_data *pdata = client->dev.platform_data;
+ unsigned long flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING
+ | IRQF_ONESHOT;
+ int ret = -EINVAL, i, __irq;
+
+ if (pdata->irq_base != -1) {
+ ret = pca957x_read_reg(chip, PCA957X_IN, &chip->irq_stat);
+ if (ret)
+ goto out;
+
+ chip->irq_stat &= chip->reg_direction;
+ chip->irq_base = pdata->irq_base;
+ mutex_init(&chip->irq_lock);
+
+ for (i = 0; i < chip->gpio_chip.ngpio; i++) {
+ __irq = i + chip->irq_base;
+ set_irq_chip_data(__irq, chip);
+ set_irq_chip_and_handler(__irq, &pca957x_irq_chip,
+ handle_edge_irq);
+ set_irq_nested_thread(__irq, 1);
+#ifdef CONFIG_ARM
+ set_irq_flags(__irq, IRQF_VALID);
+#else
+ set_irq_noprobe(irq);
+#endif
+ }
+ ret = request_threaded_irq(client->irq, NULL,
+ pca957x_irq_handler, flags,
+ dev_name(&client->dev), chip);
+ if (ret) {
+ dev_err(&client->dev, "failed to request irq %d\n",
+ client->irq);
+ goto out;
+ }
+ chip->gpio_chip.to_irq = pca957x_gpio_to_irq;
+ } else
+ goto out;
+
+ return 0;
+out:
+ chip->irq_base = -1;
+ return ret;
+}
+
+static void pca957x_irq_teardown(struct pca957x_chip *chip)
+{
+ if (chip->irq_base != -1)
+ free_irq(chip->client->irq, chip);
+}
+
+static int __devinit pca957x_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct pca957x_platform_data *pdata;
+ struct pca957x_chip *chip;
+ int ret, retval;
+ uint16_t val;
+
+ pdata = client->dev.platform_data;
+ if (pdata == NULL) {
+ dev_dbg(&client->dev, "no platform data\n");
+ return -EINVAL;
+ }
+
+ chip = kzalloc(sizeof(struct pca957x_chip), GFP_KERNEL);
+ if (chip == NULL)
+ return -ENOMEM;
+
+ chip->client = client;
+
+ chip->gpio_start = pdata->gpio_base;
+
+ /*
+ * Initialize cached registers from their original values.
+ * We can't share this chip with another i2c master.
+ */
+ pca957x_setup_gpio(chip, id->driver_data);
+
+ /* Let every port in proper state , that could save power */
+ pca957x_write_reg(chip, PCA957X_PUPD, 0x0);
+ pca957x_write_reg(chip, PCA957X_CFG, 0xffff);
+ pca957x_write_reg(chip, PCA957X_OUT, 0x0);
+
+ ret = pca957x_read_reg(chip, PCA957X_IN, &val);
+ if (ret)
+ goto out;
+
+ ret = pca957x_read_reg(chip, PCA957X_OUT, &chip->reg_output);
+ if (ret)
+ goto out;
+
+ ret = pca957x_read_reg(chip, PCA957X_CFG, &chip->reg_direction);
+ if (ret)
+ goto out;
+
+ /* set platform specific polarity inversion */
+ ret = pca957x_write_reg(chip, PCA957X_INVRT, pdata->invert);
+ if (ret)
+ goto out;
+
+ /* To enable register 6, 7 to controll pull up and pull down */
+ pca957x_write_reg(chip, PCA957X_BKEN, 0x202);
+
+ ret = gpiochip_add(&chip->gpio_chip);
+ if (ret)
+ goto out;
+
+ if (pdata->setup) {
+ ret = pdata->setup(client, chip->gpio_chip.base,
+ chip->gpio_chip.ngpio, pdata->context);
+ if (ret < 0)
+ dev_warn(&client->dev, "setup failed, %d\n", ret);
+ }
+
+ ret = pca957x_init_irq(chip);
+ if (ret)
+ goto out_irq;
+
+ i2c_set_clientdata(client, chip);
+ return 0;
+
+out_irq:
+ retval = gpiochip_remove(&chip->gpio_chip);
+out:
+ kfree(chip);
+ return ret;
+}
+
+static int __devexit pca957x_remove(struct i2c_client *client)
+{
+ struct pca957x_platform_data *pdata = client->dev.platform_data;
+ struct pca957x_chip *chip = i2c_get_clientdata(client);
+ int ret = 0;
+
+ if (pdata->teardown) {
+ ret = pdata->teardown(client, chip->gpio_chip.base,
+ chip->gpio_chip.ngpio, pdata->context);
+ if (ret < 0) {
+ dev_err(&client->dev, "%s failed, ret:%d\n",
+ "teardown", ret);
+ return ret;
+ }
+ }
+
+ ret = gpiochip_remove(&chip->gpio_chip);
+ if (ret) {
+ dev_err(&client->dev, "%s failed, ret:%d\n",
+ "gpiochip_remove()", ret);
+ return ret;
+ }
+
+ pca957x_irq_teardown(chip);
+ kfree(chip);
+ return 0;
+}
+
+static struct i2c_driver pca957x_driver = {
+ .driver = {
+ .name = "pca9575",
+ },
+ .probe = pca957x_probe,
+ .remove = __devexit_p(pca957x_remove),
+ .id_table = pca957x_id,
+};
+
+static int __init pca957x_init(void)
+{
+ return i2c_add_driver(&pca957x_driver);
+}
+/*
+ * register after i2c postcore initcall and before
+ * subsys initcalls that may rely on these GPIOs
+ */
+subsys_initcall_sync(pca957x_init);
+
+static void __exit pca957x_exit(void)
+{
+ i2c_del_driver(&pca957x_driver);
+}
+module_exit(pca957x_exit);
+
+MODULE_AUTHOR("Jack Ren <jack.ren@marvell.com>");
+MODULE_DESCRIPTION("GPIO expander driver for PCA957x");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/i2c/pca957x.h b/include/linux/i2c/pca957x.h
new file mode 100644
index 0000000..dd78b63
--- /dev/null
+++ b/include/linux/i2c/pca957x.h
@@ -0,0 +1,28 @@
+#ifndef _LINUX_PCA957X_H
+#define _LINUX_PCA957X_H
+
+#include <linux/types.h>
+#include <linux/i2c.h>
+
+struct pca957x_platform_data {
+ /* number of the first GPIO */
+ unsigned gpio_base;
+
+ /* initial polarity inversion setting */
+ uint16_t invert;
+
+ /* interrupt base */
+ int irq_base;
+
+ void *context; /* param to setup/teardown */
+
+ int (*setup)(struct i2c_client *client,
+ unsigned gpio, unsigned ngpio,
+ void *context);
+ int (*teardown)(struct i2c_client *client,
+ unsigned gpio, unsigned ngpio,
+ void *context);
+ const char *const *names;
+};
+
+#endif /* _LINUX_PCA957X_H */
--
1.5.6.5


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