diff options
Diffstat (limited to 'drivers/gpio/gpio-pca953x.c')
| -rw-r--r-- | drivers/gpio/gpio-pca953x.c | 768 |
1 files changed, 768 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c new file mode 100644 index 000000000000..a610864b7e13 --- /dev/null +++ b/drivers/gpio/gpio-pca953x.c @@ -0,0 +1,768 @@ +/* + * PCA953x 4/8/16 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/gpio.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/i2c.h> +#include <linux/i2c/pca953x.h> +#include <linux/slab.h> +#ifdef CONFIG_OF_GPIO +#include <linux/of_platform.h> +#include <linux/of_gpio.h> +#endif + +#define PCA953X_INPUT 0 +#define PCA953X_OUTPUT 1 +#define PCA953X_INVERT 2 +#define PCA953X_DIRECTION 3 + +#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 + +#define PCA_GPIO_MASK 0x00FF +#define PCA_INT 0x0100 +#define PCA953X_TYPE 0x1000 +#define PCA957X_TYPE 0x2000 + +static const struct i2c_device_id pca953x_id[] = { + { "pca9534", 8 | PCA953X_TYPE | PCA_INT, }, + { "pca9535", 16 | PCA953X_TYPE | PCA_INT, }, + { "pca9536", 4 | PCA953X_TYPE, }, + { "pca9537", 4 | PCA953X_TYPE | PCA_INT, }, + { "pca9538", 8 | PCA953X_TYPE | PCA_INT, }, + { "pca9539", 16 | PCA953X_TYPE | PCA_INT, }, + { "pca9554", 8 | PCA953X_TYPE | PCA_INT, }, + { "pca9555", 16 | PCA953X_TYPE | PCA_INT, }, + { "pca9556", 8 | PCA953X_TYPE, }, + { "pca9557", 8 | PCA953X_TYPE, }, + { "pca9574", 8 | PCA957X_TYPE | PCA_INT, }, + { "pca9575", 16 | PCA957X_TYPE | PCA_INT, }, + + { "max7310", 8 | PCA953X_TYPE, }, + { "max7312", 16 | PCA953X_TYPE | PCA_INT, }, + { "max7313", 16 | PCA953X_TYPE | PCA_INT, }, + { "max7315", 8 | PCA953X_TYPE | PCA_INT, }, + { "pca6107", 8 | PCA953X_TYPE | PCA_INT, }, + { "tca6408", 8 | PCA953X_TYPE | PCA_INT, }, + { "tca6416", 16 | PCA953X_TYPE | PCA_INT, }, + /* NYET: { "tca6424", 24, }, */ + { } +}; +MODULE_DEVICE_TABLE(i2c, pca953x_id); + +struct pca953x_chip { + unsigned gpio_start; + uint16_t reg_output; + uint16_t reg_direction; + struct mutex i2c_lock; + +#ifdef CONFIG_GPIO_PCA953X_IRQ + 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; +#endif + + struct i2c_client *client; + struct pca953x_platform_data *dyn_pdata; + struct gpio_chip gpio_chip; + const char *const *names; + int chip_type; +}; + +static int pca953x_write_reg(struct pca953x_chip *chip, int reg, uint16_t val) +{ + int ret = 0; + + if (chip->gpio_chip.ngpio <= 8) + ret = i2c_smbus_write_byte_data(chip->client, reg, val); + else { + switch (chip->chip_type) { + case PCA953X_TYPE: + ret = i2c_smbus_write_word_data(chip->client, + reg << 1, val); + break; + case PCA957X_TYPE: + ret = i2c_smbus_write_byte_data(chip->client, reg << 1, + val & 0xff); + if (ret < 0) + break; + ret = i2c_smbus_write_byte_data(chip->client, + (reg << 1) + 1, + (val & 0xff00) >> 8); + break; + } + } + + if (ret < 0) { + dev_err(&chip->client->dev, "failed writing register\n"); + return ret; + } + + return 0; +} + +static int pca953x_read_reg(struct pca953x_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 pca953x_gpio_direction_input(struct gpio_chip *gc, unsigned off) +{ + struct pca953x_chip *chip; + uint16_t reg_val; + int ret, offset = 0; + + chip = container_of(gc, struct pca953x_chip, gpio_chip); + + mutex_lock(&chip->i2c_lock); + reg_val = chip->reg_direction | (1u << off); + + switch (chip->chip_type) { + case PCA953X_TYPE: + offset = PCA953X_DIRECTION; + break; + case PCA957X_TYPE: + offset = PCA957X_CFG; + break; + } + ret = pca953x_write_reg(chip, offset, reg_val); + if (ret) + goto exit; + + chip->reg_direction = reg_val; + ret = 0; +exit: + mutex_unlock(&chip->i2c_lock); + return ret; +} + +static int pca953x_gpio_direction_output(struct gpio_chip *gc, + unsigned off, int val) +{ + struct pca953x_chip *chip; + uint16_t reg_val; + int ret, offset = 0; + + chip = container_of(gc, struct pca953x_chip, gpio_chip); + + mutex_lock(&chip->i2c_lock); + /* set output level */ + if (val) + reg_val = chip->reg_output | (1u << off); + else + reg_val = chip->reg_output & ~(1u << off); + + switch (chip->chip_type) { + case PCA953X_TYPE: + offset = PCA953X_OUTPUT; + break; + case PCA957X_TYPE: + offset = PCA957X_OUT; + break; + } + ret = pca953x_write_reg(chip, offset, reg_val); + if (ret) + goto exit; + + chip->reg_output = reg_val; + + /* then direction */ + reg_val = chip->reg_direction & ~(1u << off); + switch (chip->chip_type) { + case PCA953X_TYPE: + offset = PCA953X_DIRECTION; + break; + case PCA957X_TYPE: + offset = PCA957X_CFG; + break; + } + ret = pca953x_write_reg(chip, offset, reg_val); + if (ret) + goto exit; + + chip->reg_direction = reg_val; + ret = 0; +exit: + mutex_unlock(&chip->i2c_lock); + return ret; +} + +static int pca953x_gpio_get_value(struct gpio_chip *gc, unsigned off) +{ + struct pca953x_chip *chip; + uint16_t reg_val; + int ret, offset = 0; + + chip = container_of(gc, struct pca953x_chip, gpio_chip); + + mutex_lock(&chip->i2c_lock); + switch (chip->chip_type) { + case PCA953X_TYPE: + offset = PCA953X_INPUT; + break; + case PCA957X_TYPE: + offset = PCA957X_IN; + break; + } + ret = pca953x_read_reg(chip, offset, ®_val); + mutex_unlock(&chip->i2c_lock); + 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 pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) +{ + struct pca953x_chip *chip; + uint16_t reg_val; + int ret, offset = 0; + + chip = container_of(gc, struct pca953x_chip, gpio_chip); + + mutex_lock(&chip->i2c_lock); + if (val) + reg_val = chip->reg_output | (1u << off); + else + reg_val = chip->reg_output & ~(1u << off); + + switch (chip->chip_type) { + case PCA953X_TYPE: + offset = PCA953X_OUTPUT; + break; + case PCA957X_TYPE: + offset = PCA957X_OUT; + break; + } + ret = pca953x_write_reg(chip, offset, reg_val); + if (ret) + goto exit; + + chip->reg_output = reg_val; +exit: + mutex_unlock(&chip->i2c_lock); +} + +static void pca953x_setup_gpio(struct pca953x_chip *chip, int gpios) +{ + struct gpio_chip *gc; + + gc = &chip->gpio_chip; + + gc->direction_input = pca953x_gpio_direction_input; + gc->direction_output = pca953x_gpio_direction_output; + gc->get = pca953x_gpio_get_value; + gc->set = pca953x_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; + gc->names = chip->names; +} + +#ifdef CONFIG_GPIO_PCA953X_IRQ +static int pca953x_gpio_to_irq(struct gpio_chip *gc, unsigned off) +{ + struct pca953x_chip *chip; + + chip = container_of(gc, struct pca953x_chip, gpio_chip); + return chip->irq_base + off; +} + +static void pca953x_irq_mask(struct irq_data *d) +{ + struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); + + chip->irq_mask &= ~(1 << (d->irq - chip->irq_base)); +} + +static void pca953x_irq_unmask(struct irq_data *d) +{ + struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); + + chip->irq_mask |= 1 << (d->irq - chip->irq_base); +} + +static void pca953x_irq_bus_lock(struct irq_data *d) +{ + struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); + + mutex_lock(&chip->irq_lock); +} + +static void pca953x_irq_bus_sync_unlock(struct irq_data *d) +{ + struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); + uint16_t new_irqs; + uint16_t level; + + /* Look for any newly setup interrupt */ + new_irqs = chip->irq_trig_fall | chip->irq_trig_raise; + new_irqs &= ~chip->reg_direction; + + while (new_irqs) { + level = __ffs(new_irqs); + pca953x_gpio_direction_input(&chip->gpio_chip, level); + new_irqs &= ~(1 << level); + } + + mutex_unlock(&chip->irq_lock); +} + +static int pca953x_irq_set_type(struct irq_data *d, unsigned int type) +{ + struct pca953x_chip *chip = irq_data_get_irq_chip_data(d); + uint16_t level = d->irq - chip->irq_base; + uint16_t mask = 1 << level; + + 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_FALLING) + chip->irq_trig_fall |= mask; + else + chip->irq_trig_fall &= ~mask; + + if (type & IRQ_TYPE_EDGE_RISING) + chip->irq_trig_raise |= mask; + else + chip->irq_trig_raise &= ~mask; + + return 0; +} + +static struct irq_chip pca953x_irq_chip = { + .name = "pca953x", + .irq_mask = pca953x_irq_mask, + .irq_unmask = pca953x_irq_unmask, + .irq_bus_lock = pca953x_irq_bus_lock, + .irq_bus_sync_unlock = pca953x_irq_bus_sync_unlock, + .irq_set_type = pca953x_irq_set_type, +}; + +static uint16_t pca953x_irq_pending(struct pca953x_chip *chip) +{ + uint16_t cur_stat; + uint16_t old_stat; + uint16_t pending; + uint16_t trigger; + int ret, offset = 0; + + switch (chip->chip_type) { + case PCA953X_TYPE: + offset = PCA953X_INPUT; + break; + case PCA957X_TYPE: + offset = PCA957X_IN; + break; + } + ret = pca953x_read_reg(chip, offset, &cur_stat); + if (ret) + return 0; + + /* Remove output pins from the equation */ + cur_stat &= chip->reg_direction; + + old_stat = chip->irq_stat; + trigger = (cur_stat ^ old_stat) & chip->irq_mask; + + if (!trigger) + return 0; + + chip->irq_stat = cur_stat; + + pending = (old_stat & chip->irq_trig_fall) | + (cur_stat & chip->irq_trig_raise); + pending &= trigger; + + return pending; +} + +static irqreturn_t pca953x_irq_handler(int irq, void *devid) +{ + struct pca953x_chip *chip = devid; + uint16_t pending; + uint16_t level; + + pending = pca953x_irq_pending(chip); + + if (!pending) + return IRQ_HANDLED; + + do { + level = __ffs(pending); + generic_handle_irq(level + chip->irq_base); + + pending &= ~(1 << level); + } while (pending); + + return IRQ_HANDLED; +} + +static int pca953x_irq_setup(struct pca953x_chip *chip, + const struct i2c_device_id *id) +{ + struct i2c_client *client = chip->client; + struct pca953x_platform_data *pdata = client->dev.platform_data; + int ret, offset = 0; + + if (pdata->irq_base != -1 + && (id->driver_data & PCA_INT)) { + int lvl; + + switch (chip->chip_type) { + case PCA953X_TYPE: + offset = PCA953X_INPUT; + break; + case PCA957X_TYPE: + offset = PCA957X_IN; + break; + } + ret = pca953x_read_reg(chip, offset, &chip->irq_stat); + if (ret) + goto out_failed; + + /* + * There is no way to know which GPIO line generated the + * interrupt. We have to rely on the previous read for + * this purpose. + */ + chip->irq_stat &= chip->reg_direction; + chip->irq_base = pdata->irq_base; + mutex_init(&chip->irq_lock); + + for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) { + int irq = lvl + chip->irq_base; + + irq_set_chip_data(irq, chip); + irq_set_chip_and_handler(irq, &pca953x_irq_chip, + handle_simple_irq); +#ifdef CONFIG_ARM + set_irq_flags(irq, IRQF_VALID); +#else + irq_set_noprobe(irq); +#endif + } + + ret = request_threaded_irq(client->irq, + NULL, + pca953x_irq_handler, + IRQF_TRIGGER_FALLING | IRQF_ONESHOT, + dev_name(&client->dev), chip); + if (ret) { + dev_err(&client->dev, "failed to request irq %d\n", + client->irq); + goto out_failed; + } + + chip->gpio_chip.to_irq = pca953x_gpio_to_irq; + } + + return 0; + +out_failed: + chip->irq_base = -1; + return ret; +} + +static void pca953x_irq_teardown(struct pca953x_chip *chip) +{ + if (chip->irq_base != -1) + free_irq(chip->client->irq, chip); +} +#else /* CONFIG_GPIO_PCA953X_IRQ */ +static int pca953x_irq_setup(struct pca953x_chip *chip, + const struct i2c_device_id *id) +{ + struct i2c_client *client = chip->client; + struct pca953x_platform_data *pdata = client->dev.platform_data; + + if (pdata->irq_base != -1 && (id->driver_data & PCA_INT)) + dev_warn(&client->dev, "interrupt support not compiled in\n"); + + return 0; +} + +static void pca953x_irq_teardown(struct pca953x_chip *chip) +{ +} +#endif + +/* + * Handlers for alternative sources of platform_data + */ +#ifdef CONFIG_OF_GPIO +/* + * Translate OpenFirmware node properties into platform_data + */ +static struct pca953x_platform_data * +pca953x_get_alt_pdata(struct i2c_client *client) +{ + struct pca953x_platform_data *pdata; + struct device_node *node; + const __be32 *val; + int size; + + node = client->dev.of_node; + if (node == NULL) + return NULL; + + pdata = kzalloc(sizeof(struct pca953x_platform_data), GFP_KERNEL); + if (pdata == NULL) { + dev_err(&client->dev, "Unable to allocate platform_data\n"); + return NULL; + } + + pdata->gpio_base = -1; + val = of_get_property(node, "linux,gpio-base", &size); + if (val) { + if (size != sizeof(*val)) + dev_warn(&client->dev, "%s: wrong linux,gpio-base\n", + node->full_name); + else + pdata->gpio_base = be32_to_cpup(val); + } + + val = of_get_property(node, "polarity", NULL); + if (val) + pdata->invert = *val; + + return pdata; +} +#else +static struct pca953x_platform_data * +pca953x_get_alt_pdata(struct i2c_client *client) +{ + return NULL; +} +#endif + +static int __devinit device_pca953x_init(struct pca953x_chip *chip, int invert) +{ + int ret; + + ret = pca953x_read_reg(chip, PCA953X_OUTPUT, &chip->reg_output); + if (ret) + goto out; + + ret = pca953x_read_reg(chip, PCA953X_DIRECTION, + &chip->reg_direction); + if (ret) + goto out; + + /* set platform specific polarity inversion */ + ret = pca953x_write_reg(chip, PCA953X_INVERT, invert); + if (ret) + goto out; + return 0; +out: + return ret; +} + +static int __devinit device_pca957x_init(struct pca953x_chip *chip, int invert) +{ + int ret; + uint16_t val = 0; + + /* Let every port in proper state, that could save power */ + pca953x_write_reg(chip, PCA957X_PUPD, 0x0); + pca953x_write_reg(chip, PCA957X_CFG, 0xffff); + pca953x_write_reg(chip, PCA957X_OUT, 0x0); + + ret = pca953x_read_reg(chip, PCA957X_IN, &val); + if (ret) + goto out; + ret = pca953x_read_reg(chip, PCA957X_OUT, &chip->reg_output); + if (ret) + goto out; + ret = pca953x_read_reg(chip, PCA957X_CFG, &chip->reg_direction); + if (ret) + goto out; + + /* set platform specific polarity inversion */ + pca953x_write_reg(chip, PCA957X_INVRT, invert); + + /* To enable register 6, 7 to controll pull up and pull down */ + pca953x_write_reg(chip, PCA957X_BKEN, 0x202); + + return 0; +out: + return ret; +} + +static int __devinit pca953x_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct pca953x_platform_data *pdata; + struct pca953x_chip *chip; + int ret = 0; + + chip = kzalloc(sizeof(struct pca953x_chip), GFP_KERNEL); + if (chip == NULL) + return -ENOMEM; + + pdata = client->dev.platform_data; + if (pdata == NULL) { + pdata = pca953x_get_alt_pdata(client); + /* + * Unlike normal platform_data, this is allocated + * dynamically and must be freed in the driver + */ + chip->dyn_pdata = pdata; + } + + if (pdata == NULL) { + dev_dbg(&client->dev, "no platform data\n"); + ret = -EINVAL; + goto out_failed; + } + + chip->client = client; + + chip->gpio_start = pdata->gpio_base; + + chip->names = pdata->names; + chip->chip_type = id->driver_data & (PCA953X_TYPE | PCA957X_TYPE); + + mutex_init(&chip->i2c_lock); + + /* initialize cached registers from their original values. + * we can't share this chip with another i2c master. + */ + pca953x_setup_gpio(chip, id->driver_data & PCA_GPIO_MASK); + + if (chip->chip_type == PCA953X_TYPE) + device_pca953x_init(chip, pdata->invert); + else if (chip->chip_type == PCA957X_TYPE) + device_pca957x_init(chip, pdata->invert); + else + goto out_failed; + + ret = pca953x_irq_setup(chip, id); + if (ret) + goto out_failed; + + ret = gpiochip_add(&chip->gpio_chip); + if (ret) + goto out_failed_irq; + + 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); + } + + i2c_set_clientdata(client, chip); + return 0; + +out_failed_irq: + pca953x_irq_teardown(chip); +out_failed: + kfree(chip->dyn_pdata); + kfree(chip); + return ret; +} + +static int pca953x_remove(struct i2c_client *client) +{ + struct pca953x_platform_data *pdata = client->dev.platform_data; + struct pca953x_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, %d\n", + "teardown", ret); + return ret; + } + } + + ret = gpiochip_remove(&chip->gpio_chip); + if (ret) { + dev_err(&client->dev, "%s failed, %d\n", + "gpiochip_remove()", ret); + return ret; + } + + pca953x_irq_teardown(chip); + kfree(chip->dyn_pdata); + kfree(chip); + return 0; +} + +static struct i2c_driver pca953x_driver = { + .driver = { + .name = "pca953x", + }, + .probe = pca953x_probe, + .remove = pca953x_remove, + .id_table = pca953x_id, +}; + +static int __init pca953x_init(void) +{ + return i2c_add_driver(&pca953x_driver); +} +/* register after i2c postcore initcall and before + * subsys initcalls that may rely on these GPIOs + */ +subsys_initcall(pca953x_init); + +static void __exit pca953x_exit(void) +{ + i2c_del_driver(&pca953x_driver); +} +module_exit(pca953x_exit); + +MODULE_AUTHOR("eric miao <eric.miao@marvell.com>"); +MODULE_DESCRIPTION("GPIO expander driver for PCA953x"); +MODULE_LICENSE("GPL"); |