diff options
Diffstat (limited to 'drivers/gpio/max732x.c')
| -rw-r--r-- | drivers/gpio/max732x.c | 355 |
1 files changed, 336 insertions, 19 deletions
diff --git a/drivers/gpio/max732x.c b/drivers/gpio/max732x.c index f7868243af8..2053ba9cbfa 100644 --- a/drivers/gpio/max732x.c +++ b/drivers/gpio/max732x.c @@ -17,7 +17,8 @@ #include <linux/slab.h> #include <linux/string.h> #include <linux/gpio.h> - +#include <linux/interrupt.h> +#include <linux/irq.h> #include <linux/i2c.h> #include <linux/i2c/max732x.h> @@ -31,7 +32,8 @@ * - Open Drain I/O * * designated by 'O', 'I' and 'P' individually according to MAXIM's - * datasheets. + * datasheets. 'I' and 'P' ports are interrupt capables, some with + * a dedicated interrupt mask. * * There are two groups of I/O ports, each group usually includes * up to 8 I/O ports, and is accessed by a specific I2C address: @@ -44,7 +46,8 @@ * * Within each group of ports, there are five known combinations of * I/O ports: 4I4O, 4P4O, 8I, 8P, 8O, see the definitions below for - * the detailed organization of these ports. + * the detailed organization of these ports. Only Goup A is interrupt + * capable. * * GPIO numbers start from 'gpio_base + 0' to 'gpio_base + 8/16', * and GPIOs from GROUP_A are numbered before those from GROUP_B @@ -68,16 +71,47 @@ #define GROUP_A(x) ((x) & 0xffff) /* I2C Addr: 0b'110xxxx */ #define GROUP_B(x) ((x) << 16) /* I2C Addr: 0b'101xxxx */ +#define INT_NONE 0x0 /* No interrupt capability */ +#define INT_NO_MASK 0x1 /* Has interrupts, no mask */ +#define INT_INDEP_MASK 0x2 /* Has interrupts, independent mask */ +#define INT_MERGED_MASK 0x3 /* Has interrupts, merged mask */ + +#define INT_CAPS(x) (((uint64_t)(x)) << 32) + +enum { + MAX7319, + MAX7320, + MAX7321, + MAX7322, + MAX7323, + MAX7324, + MAX7325, + MAX7326, + MAX7327, +}; + +static uint64_t max732x_features[] = { + [MAX7319] = GROUP_A(IO_8I) | INT_CAPS(INT_MERGED_MASK), + [MAX7320] = GROUP_B(IO_8O), + [MAX7321] = GROUP_A(IO_8P) | INT_CAPS(INT_NO_MASK), + [MAX7322] = GROUP_A(IO_4I4O) | INT_CAPS(INT_MERGED_MASK), + [MAX7323] = GROUP_A(IO_4P4O) | INT_CAPS(INT_INDEP_MASK), + [MAX7324] = GROUP_A(IO_8I) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK), + [MAX7325] = GROUP_A(IO_8P) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK), + [MAX7326] = GROUP_A(IO_4I4O) | GROUP_B(IO_8O) | INT_CAPS(INT_MERGED_MASK), + [MAX7327] = GROUP_A(IO_4P4O) | GROUP_B(IO_8O) | INT_CAPS(INT_NO_MASK), +}; + static const struct i2c_device_id max732x_id[] = { - { "max7319", GROUP_A(IO_8I) }, - { "max7320", GROUP_B(IO_8O) }, - { "max7321", GROUP_A(IO_8P) }, - { "max7322", GROUP_A(IO_4I4O) }, - { "max7323", GROUP_A(IO_4P4O) }, - { "max7324", GROUP_A(IO_8I) | GROUP_B(IO_8O) }, - { "max7325", GROUP_A(IO_8P) | GROUP_B(IO_8O) }, - { "max7326", GROUP_A(IO_4I4O) | GROUP_B(IO_8O) }, - { "max7327", GROUP_A(IO_4P4O) | GROUP_B(IO_8O) }, + { "max7319", MAX7319 }, + { "max7320", MAX7320 }, + { "max7321", MAX7321 }, + { "max7322", MAX7322 }, + { "max7323", MAX7323 }, + { "max7324", MAX7324 }, + { "max7325", MAX7325 }, + { "max7326", MAX7326 }, + { "max7327", MAX7327 }, { }, }; MODULE_DEVICE_TABLE(i2c, max732x_id); @@ -96,9 +130,19 @@ struct max732x_chip { struct mutex lock; uint8_t reg_out[2]; + +#ifdef CONFIG_GPIO_MAX732X_IRQ + struct mutex irq_lock; + int irq_base; + uint8_t irq_mask; + uint8_t irq_mask_cur; + uint8_t irq_trig_raise; + uint8_t irq_trig_fall; + uint8_t irq_features; +#endif }; -static int max732x_write(struct max732x_chip *chip, int group_a, uint8_t val) +static int max732x_writeb(struct max732x_chip *chip, int group_a, uint8_t val) { struct i2c_client *client; int ret; @@ -113,7 +157,7 @@ static int max732x_write(struct max732x_chip *chip, int group_a, uint8_t val) return 0; } -static int max732x_read(struct max732x_chip *chip, int group_a, uint8_t *val) +static int max732x_readb(struct max732x_chip *chip, int group_a, uint8_t *val) { struct i2c_client *client; int ret; @@ -142,7 +186,7 @@ static int max732x_gpio_get_value(struct gpio_chip *gc, unsigned off) chip = container_of(gc, struct max732x_chip, gpio_chip); - ret = max732x_read(chip, is_group_a(chip, off), ®_val); + ret = max732x_readb(chip, is_group_a(chip, off), ®_val); if (ret < 0) return 0; @@ -162,7 +206,7 @@ static void max732x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val) reg_out = (off > 7) ? chip->reg_out[1] : chip->reg_out[0]; reg_out = (val) ? reg_out | mask : reg_out & ~mask; - ret = max732x_write(chip, is_group_a(chip, off), reg_out); + ret = max732x_writeb(chip, is_group_a(chip, off), reg_out); if (ret < 0) goto out; @@ -209,12 +253,278 @@ static int max732x_gpio_direction_output(struct gpio_chip *gc, return 0; } +#ifdef CONFIG_GPIO_MAX732X_IRQ +static int max732x_writew(struct max732x_chip *chip, uint16_t val) +{ + int ret; + + val = cpu_to_le16(val); + + ret = i2c_master_send(chip->client_group_a, (char *)&val, 2); + if (ret < 0) { + dev_err(&chip->client_group_a->dev, "failed writing\n"); + return ret; + } + + return 0; +} + +static int max732x_readw(struct max732x_chip *chip, uint16_t *val) +{ + int ret; + + ret = i2c_master_recv(chip->client_group_a, (char *)val, 2); + if (ret < 0) { + dev_err(&chip->client_group_a->dev, "failed reading\n"); + return ret; + } + + *val = le16_to_cpu(*val); + return 0; +} + +static void max732x_irq_update_mask(struct max732x_chip *chip) +{ + uint16_t msg; + + if (chip->irq_mask == chip->irq_mask_cur) + return; + + chip->irq_mask = chip->irq_mask_cur; + + if (chip->irq_features == INT_NO_MASK) + return; + + mutex_lock(&chip->lock); + + switch (chip->irq_features) { + case INT_INDEP_MASK: + msg = (chip->irq_mask << 8) | chip->reg_out[0]; + max732x_writew(chip, msg); + break; + + case INT_MERGED_MASK: + msg = chip->irq_mask | chip->reg_out[0]; + max732x_writeb(chip, 1, (uint8_t)msg); + break; + } + + mutex_unlock(&chip->lock); +} + +static int max732x_gpio_to_irq(struct gpio_chip *gc, unsigned off) +{ + struct max732x_chip *chip; + + chip = container_of(gc, struct max732x_chip, gpio_chip); + return chip->irq_base + off; +} + +static void max732x_irq_mask(unsigned int irq) +{ + struct max732x_chip *chip = get_irq_chip_data(irq); + + chip->irq_mask_cur &= ~(1 << (irq - chip->irq_base)); +} + +static void max732x_irq_unmask(unsigned int irq) +{ + struct max732x_chip *chip = get_irq_chip_data(irq); + + chip->irq_mask_cur |= 1 << (irq - chip->irq_base); +} + +static void max732x_irq_bus_lock(unsigned int irq) +{ + struct max732x_chip *chip = get_irq_chip_data(irq); + + mutex_lock(&chip->irq_lock); + chip->irq_mask_cur = chip->irq_mask; +} + +static void max732x_irq_bus_sync_unlock(unsigned int irq) +{ + struct max732x_chip *chip = get_irq_chip_data(irq); + + max732x_irq_update_mask(chip); + mutex_unlock(&chip->irq_lock); +} + +static int max732x_irq_set_type(unsigned int irq, unsigned int type) +{ + struct max732x_chip *chip = get_irq_chip_data(irq); + uint16_t off = irq - chip->irq_base; + uint16_t mask = 1 << off; + + if (!(mask & chip->dir_input)) { + dev_dbg(&chip->client->dev, "%s port %d is output only\n", + chip->client->name, off); + return -EACCES; + } + + if (!(type & IRQ_TYPE_EDGE_BOTH)) { + dev_err(&chip->client->dev, "irq %d: unsupported type %d\n", + 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 max732x_gpio_direction_input(&chip->gpio_chip, off); +} + +static struct irq_chip max732x_irq_chip = { + .name = "max732x", + .mask = max732x_irq_mask, + .unmask = max732x_irq_unmask, + .bus_lock = max732x_irq_bus_lock, + .bus_sync_unlock = max732x_irq_bus_sync_unlock, + .set_type = max732x_irq_set_type, +}; + +static uint8_t max732x_irq_pending(struct max732x_chip *chip) +{ + uint8_t cur_stat; + uint8_t old_stat; + uint8_t trigger; + uint8_t pending; + uint16_t status; + int ret; + + ret = max732x_readw(chip, &status); + if (ret) + return 0; + + trigger = status >> 8; + trigger &= chip->irq_mask; + + if (!trigger) + return 0; + + cur_stat = status & 0xFF; + cur_stat &= chip->irq_mask; + + old_stat = cur_stat ^ trigger; + + pending = (old_stat & chip->irq_trig_fall) | + (cur_stat & chip->irq_trig_raise); + pending &= trigger; + + return pending; +} + +static irqreturn_t max732x_irq_handler(int irq, void *devid) +{ + struct max732x_chip *chip = devid; + uint8_t pending; + uint8_t level; + + pending = max732x_irq_pending(chip); + + if (!pending) + return IRQ_HANDLED; + + do { + level = __ffs(pending); + handle_nested_irq(level + chip->irq_base); + + pending &= ~(1 << level); + } while (pending); + + return IRQ_HANDLED; +} + +static int max732x_irq_setup(struct max732x_chip *chip, + const struct i2c_device_id *id) +{ + struct i2c_client *client = chip->client; + struct max732x_platform_data *pdata = client->dev.platform_data; + int has_irq = max732x_features[id->driver_data] >> 32; + int ret; + + if (pdata->irq_base && has_irq != INT_NONE) { + int lvl; + + chip->irq_base = pdata->irq_base; + chip->irq_features = has_irq; + mutex_init(&chip->irq_lock); + + for (lvl = 0; lvl < chip->gpio_chip.ngpio; lvl++) { + int irq = lvl + chip->irq_base; + + if (!(chip->dir_input & (1 << lvl))) + continue; + + set_irq_chip_data(irq, chip); + set_irq_chip_and_handler(irq, &max732x_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, + max732x_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 = max732x_gpio_to_irq; + } + + return 0; + +out_failed: + chip->irq_base = 0; + return ret; +} + +static void max732x_irq_teardown(struct max732x_chip *chip) +{ + if (chip->irq_base) + free_irq(chip->client->irq, chip); +} +#else /* CONFIG_GPIO_MAX732X_IRQ */ +static int max732x_irq_setup(struct max732x_chip *chip, + const struct i2c_device_id *id) +{ + struct i2c_client *client = chip->client; + struct max732x_platform_data *pdata = client->dev.platform_data; + int has_irq = max732x_features[id->driver_data] >> 32; + + if (pdata->irq_base && has_irq != INT_NONE) + dev_warn(&client->dev, "interrupt support not compiled in\n"); + + return 0; +} + +static void max732x_irq_teardown(struct max732x_chip *chip) +{ +} +#endif + static int __devinit max732x_setup_gpio(struct max732x_chip *chip, const struct i2c_device_id *id, unsigned gpio_start) { struct gpio_chip *gc = &chip->gpio_chip; - uint32_t id_data = id->driver_data; + uint32_t id_data = (uint32_t)max732x_features[id->driver_data]; int i, port = 0; for (i = 0; i < 16; i++, id_data >>= 2) { @@ -306,9 +616,13 @@ static int __devinit max732x_probe(struct i2c_client *client, mutex_init(&chip->lock); - max732x_read(chip, is_group_a(chip, 0), &chip->reg_out[0]); + max732x_readb(chip, is_group_a(chip, 0), &chip->reg_out[0]); if (nr_port > 7) - max732x_read(chip, is_group_a(chip, 8), &chip->reg_out[1]); + max732x_readb(chip, is_group_a(chip, 8), &chip->reg_out[1]); + + ret = max732x_irq_setup(chip, id); + if (ret) + goto out_failed; ret = gpiochip_add(&chip->gpio_chip); if (ret) @@ -325,6 +639,7 @@ static int __devinit max732x_probe(struct i2c_client *client, return 0; out_failed: + max732x_irq_teardown(chip); kfree(chip); return ret; } @@ -352,6 +667,8 @@ static int __devexit max732x_remove(struct i2c_client *client) return ret; } + max732x_irq_teardown(chip); + /* unregister any dummy i2c_client */ if (chip->client_dummy) i2c_unregister_device(chip->client_dummy); |