diff options
Diffstat (limited to 'drivers/gpio/gpio-adnp.c')
| -rw-r--r-- | drivers/gpio/gpio-adnp.c | 561 |
1 files changed, 561 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-adnp.c b/drivers/gpio/gpio-adnp.c new file mode 100644 index 000000000..d3d0a90fe --- /dev/null +++ b/drivers/gpio/gpio-adnp.c @@ -0,0 +1,561 @@ +/* + * Copyright (C) 2011-2012 Avionic Design GmbH + * + * 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/gpio/driver.h> +#include <linux/i2c.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of_irq.h> +#include <linux/seq_file.h> +#include <linux/slab.h> + +#define GPIO_DDR(gpio) (0x00 << (gpio)->reg_shift) +#define GPIO_PLR(gpio) (0x01 << (gpio)->reg_shift) +#define GPIO_IER(gpio) (0x02 << (gpio)->reg_shift) +#define GPIO_ISR(gpio) (0x03 << (gpio)->reg_shift) +#define GPIO_PTR(gpio) (0x04 << (gpio)->reg_shift) + +struct adnp { + struct i2c_client *client; + struct gpio_chip gpio; + unsigned int reg_shift; + + struct mutex i2c_lock; + struct mutex irq_lock; + + u8 *irq_enable; + u8 *irq_level; + u8 *irq_rise; + u8 *irq_fall; + u8 *irq_high; + u8 *irq_low; +}; + +static inline struct adnp *to_adnp(struct gpio_chip *chip) +{ + return container_of(chip, struct adnp, gpio); +} + +static int adnp_read(struct adnp *adnp, unsigned offset, uint8_t *value) +{ + int err; + + err = i2c_smbus_read_byte_data(adnp->client, offset); + if (err < 0) { + dev_err(adnp->gpio.dev, "%s failed: %d\n", + "i2c_smbus_read_byte_data()", err); + return err; + } + + *value = err; + return 0; +} + +static int adnp_write(struct adnp *adnp, unsigned offset, uint8_t value) +{ + int err; + + err = i2c_smbus_write_byte_data(adnp->client, offset, value); + if (err < 0) { + dev_err(adnp->gpio.dev, "%s failed: %d\n", + "i2c_smbus_write_byte_data()", err); + return err; + } + + return 0; +} + +static int adnp_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct adnp *adnp = to_adnp(chip); + unsigned int reg = offset >> adnp->reg_shift; + unsigned int pos = offset & 7; + u8 value; + int err; + + err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &value); + if (err < 0) + return err; + + return (value & BIT(pos)) ? 1 : 0; +} + +static void __adnp_gpio_set(struct adnp *adnp, unsigned offset, int value) +{ + unsigned int reg = offset >> adnp->reg_shift; + unsigned int pos = offset & 7; + int err; + u8 val; + + err = adnp_read(adnp, GPIO_PLR(adnp) + reg, &val); + if (err < 0) + return; + + if (value) + val |= BIT(pos); + else + val &= ~BIT(pos); + + adnp_write(adnp, GPIO_PLR(adnp) + reg, val); +} + +static void adnp_gpio_set(struct gpio_chip *chip, unsigned offset, int value) +{ + struct adnp *adnp = to_adnp(chip); + + mutex_lock(&adnp->i2c_lock); + __adnp_gpio_set(adnp, offset, value); + mutex_unlock(&adnp->i2c_lock); +} + +static int adnp_gpio_direction_input(struct gpio_chip *chip, unsigned offset) +{ + struct adnp *adnp = to_adnp(chip); + unsigned int reg = offset >> adnp->reg_shift; + unsigned int pos = offset & 7; + u8 value; + int err; + + mutex_lock(&adnp->i2c_lock); + + err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value); + if (err < 0) + goto out; + + value &= ~BIT(pos); + + err = adnp_write(adnp, GPIO_DDR(adnp) + reg, value); + if (err < 0) + goto out; + + err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &value); + if (err < 0) + goto out; + + if (err & BIT(pos)) + err = -EACCES; + + err = 0; + +out: + mutex_unlock(&adnp->i2c_lock); + return err; +} + +static int adnp_gpio_direction_output(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct adnp *adnp = to_adnp(chip); + unsigned int reg = offset >> adnp->reg_shift; + unsigned int pos = offset & 7; + int err; + u8 val; + + mutex_lock(&adnp->i2c_lock); + + err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val); + if (err < 0) + goto out; + + val |= BIT(pos); + + err = adnp_write(adnp, GPIO_DDR(adnp) + reg, val); + if (err < 0) + goto out; + + err = adnp_read(adnp, GPIO_DDR(adnp) + reg, &val); + if (err < 0) + goto out; + + if (!(val & BIT(pos))) { + err = -EPERM; + goto out; + } + + __adnp_gpio_set(adnp, offset, value); + err = 0; + +out: + mutex_unlock(&adnp->i2c_lock); + return err; +} + +static void adnp_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) +{ + struct adnp *adnp = to_adnp(chip); + unsigned int num_regs = 1 << adnp->reg_shift, i, j; + int err; + + for (i = 0; i < num_regs; i++) { + u8 ddr, plr, ier, isr; + + mutex_lock(&adnp->i2c_lock); + + err = adnp_read(adnp, GPIO_DDR(adnp) + i, &ddr); + if (err < 0) { + mutex_unlock(&adnp->i2c_lock); + return; + } + + err = adnp_read(adnp, GPIO_PLR(adnp) + i, &plr); + if (err < 0) { + mutex_unlock(&adnp->i2c_lock); + return; + } + + err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier); + if (err < 0) { + mutex_unlock(&adnp->i2c_lock); + return; + } + + err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr); + if (err < 0) { + mutex_unlock(&adnp->i2c_lock); + return; + } + + mutex_unlock(&adnp->i2c_lock); + + for (j = 0; j < 8; j++) { + unsigned int bit = (i << adnp->reg_shift) + j; + const char *direction = "input "; + const char *level = "low "; + const char *interrupt = "disabled"; + const char *pending = ""; + + if (ddr & BIT(j)) + direction = "output"; + + if (plr & BIT(j)) + level = "high"; + + if (ier & BIT(j)) + interrupt = "enabled "; + + if (isr & BIT(j)) + pending = "pending"; + + seq_printf(s, "%2u: %s %s IRQ %s %s\n", bit, + direction, level, interrupt, pending); + } + } +} + +static int adnp_gpio_setup(struct adnp *adnp, unsigned int num_gpios) +{ + struct gpio_chip *chip = &adnp->gpio; + int err; + + adnp->reg_shift = get_count_order(num_gpios) - 3; + + chip->direction_input = adnp_gpio_direction_input; + chip->direction_output = adnp_gpio_direction_output; + chip->get = adnp_gpio_get; + chip->set = adnp_gpio_set; + chip->can_sleep = true; + + if (IS_ENABLED(CONFIG_DEBUG_FS)) + chip->dbg_show = adnp_gpio_dbg_show; + + chip->base = -1; + chip->ngpio = num_gpios; + chip->label = adnp->client->name; + chip->dev = &adnp->client->dev; + chip->of_node = chip->dev->of_node; + chip->owner = THIS_MODULE; + + err = gpiochip_add(chip); + if (err) + return err; + + return 0; +} + +static irqreturn_t adnp_irq(int irq, void *data) +{ + struct adnp *adnp = data; + unsigned int num_regs, i; + + num_regs = 1 << adnp->reg_shift; + + for (i = 0; i < num_regs; i++) { + unsigned int base = i << adnp->reg_shift, bit; + u8 changed, level, isr, ier; + unsigned long pending; + int err; + + mutex_lock(&adnp->i2c_lock); + + err = adnp_read(adnp, GPIO_PLR(adnp) + i, &level); + if (err < 0) { + mutex_unlock(&adnp->i2c_lock); + continue; + } + + err = adnp_read(adnp, GPIO_ISR(adnp) + i, &isr); + if (err < 0) { + mutex_unlock(&adnp->i2c_lock); + continue; + } + + err = adnp_read(adnp, GPIO_IER(adnp) + i, &ier); + if (err < 0) { + mutex_unlock(&adnp->i2c_lock); + continue; + } + + mutex_unlock(&adnp->i2c_lock); + + /* determine pins that changed levels */ + changed = level ^ adnp->irq_level[i]; + + /* compute edge-triggered interrupts */ + pending = changed & ((adnp->irq_fall[i] & ~level) | + (adnp->irq_rise[i] & level)); + + /* add in level-triggered interrupts */ + pending |= (adnp->irq_high[i] & level) | + (adnp->irq_low[i] & ~level); + + /* mask out non-pending and disabled interrupts */ + pending &= isr & ier; + + for_each_set_bit(bit, &pending, 8) { + unsigned int child_irq; + child_irq = irq_find_mapping(adnp->gpio.irqdomain, + base + bit); + handle_nested_irq(child_irq); + } + } + + return IRQ_HANDLED; +} + +static void adnp_irq_mask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct adnp *adnp = to_adnp(gc); + unsigned int reg = d->hwirq >> adnp->reg_shift; + unsigned int pos = d->hwirq & 7; + + adnp->irq_enable[reg] &= ~BIT(pos); +} + +static void adnp_irq_unmask(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct adnp *adnp = to_adnp(gc); + unsigned int reg = d->hwirq >> adnp->reg_shift; + unsigned int pos = d->hwirq & 7; + + adnp->irq_enable[reg] |= BIT(pos); +} + +static int adnp_irq_set_type(struct irq_data *d, unsigned int type) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct adnp *adnp = to_adnp(gc); + unsigned int reg = d->hwirq >> adnp->reg_shift; + unsigned int pos = d->hwirq & 7; + + if (type & IRQ_TYPE_EDGE_RISING) + adnp->irq_rise[reg] |= BIT(pos); + else + adnp->irq_rise[reg] &= ~BIT(pos); + + if (type & IRQ_TYPE_EDGE_FALLING) + adnp->irq_fall[reg] |= BIT(pos); + else + adnp->irq_fall[reg] &= ~BIT(pos); + + if (type & IRQ_TYPE_LEVEL_HIGH) + adnp->irq_high[reg] |= BIT(pos); + else + adnp->irq_high[reg] &= ~BIT(pos); + + if (type & IRQ_TYPE_LEVEL_LOW) + adnp->irq_low[reg] |= BIT(pos); + else + adnp->irq_low[reg] &= ~BIT(pos); + + return 0; +} + +static void adnp_irq_bus_lock(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct adnp *adnp = to_adnp(gc); + + mutex_lock(&adnp->irq_lock); +} + +static void adnp_irq_bus_unlock(struct irq_data *d) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(d); + struct adnp *adnp = to_adnp(gc); + unsigned int num_regs = 1 << adnp->reg_shift, i; + + mutex_lock(&adnp->i2c_lock); + + for (i = 0; i < num_regs; i++) + adnp_write(adnp, GPIO_IER(adnp) + i, adnp->irq_enable[i]); + + mutex_unlock(&adnp->i2c_lock); + mutex_unlock(&adnp->irq_lock); +} + +static struct irq_chip adnp_irq_chip = { + .name = "gpio-adnp", + .irq_mask = adnp_irq_mask, + .irq_unmask = adnp_irq_unmask, + .irq_set_type = adnp_irq_set_type, + .irq_bus_lock = adnp_irq_bus_lock, + .irq_bus_sync_unlock = adnp_irq_bus_unlock, +}; + +static int adnp_irq_setup(struct adnp *adnp) +{ + unsigned int num_regs = 1 << adnp->reg_shift, i; + struct gpio_chip *chip = &adnp->gpio; + int err; + + mutex_init(&adnp->irq_lock); + + /* + * Allocate memory to keep track of the current level and trigger + * modes of the interrupts. To avoid multiple allocations, a single + * large buffer is allocated and pointers are setup to point at the + * corresponding offsets. For consistency, the layout of the buffer + * is chosen to match the register layout of the hardware in that + * each segment contains the corresponding bits for all interrupts. + */ + adnp->irq_enable = devm_kzalloc(chip->dev, num_regs * 6, GFP_KERNEL); + if (!adnp->irq_enable) + return -ENOMEM; + + adnp->irq_level = adnp->irq_enable + (num_regs * 1); + adnp->irq_rise = adnp->irq_enable + (num_regs * 2); + adnp->irq_fall = adnp->irq_enable + (num_regs * 3); + adnp->irq_high = adnp->irq_enable + (num_regs * 4); + adnp->irq_low = adnp->irq_enable + (num_regs * 5); + + for (i = 0; i < num_regs; i++) { + /* + * Read the initial level of all pins to allow the emulation + * of edge triggered interrupts. + */ + err = adnp_read(adnp, GPIO_PLR(adnp) + i, &adnp->irq_level[i]); + if (err < 0) + return err; + + /* disable all interrupts */ + err = adnp_write(adnp, GPIO_IER(adnp) + i, 0); + if (err < 0) + return err; + + adnp->irq_enable[i] = 0x00; + } + + err = devm_request_threaded_irq(chip->dev, adnp->client->irq, + NULL, adnp_irq, + IRQF_TRIGGER_RISING | IRQF_ONESHOT, + dev_name(chip->dev), adnp); + if (err != 0) { + dev_err(chip->dev, "can't request IRQ#%d: %d\n", + adnp->client->irq, err); + return err; + } + + err = gpiochip_irqchip_add(chip, + &adnp_irq_chip, + 0, + handle_simple_irq, + IRQ_TYPE_NONE); + if (err) { + dev_err(chip->dev, + "could not connect irqchip to gpiochip\n"); + return err; + } + + return 0; +} + +static int adnp_i2c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device_node *np = client->dev.of_node; + struct adnp *adnp; + u32 num_gpios; + int err; + + err = of_property_read_u32(np, "nr-gpios", &num_gpios); + if (err < 0) + return err; + + client->irq = irq_of_parse_and_map(np, 0); + if (!client->irq) + return -EPROBE_DEFER; + + adnp = devm_kzalloc(&client->dev, sizeof(*adnp), GFP_KERNEL); + if (!adnp) + return -ENOMEM; + + mutex_init(&adnp->i2c_lock); + adnp->client = client; + + err = adnp_gpio_setup(adnp, num_gpios); + if (err) + return err; + + if (of_find_property(np, "interrupt-controller", NULL)) { + err = adnp_irq_setup(adnp); + if (err) + return err; + } + + i2c_set_clientdata(client, adnp); + + return 0; +} + +static int adnp_i2c_remove(struct i2c_client *client) +{ + struct adnp *adnp = i2c_get_clientdata(client); + + gpiochip_remove(&adnp->gpio); + return 0; +} + +static const struct i2c_device_id adnp_i2c_id[] = { + { "gpio-adnp" }, + { }, +}; +MODULE_DEVICE_TABLE(i2c, adnp_i2c_id); + +static const struct of_device_id adnp_of_match[] = { + { .compatible = "ad,gpio-adnp", }, + { }, +}; +MODULE_DEVICE_TABLE(of, adnp_of_match); + +static struct i2c_driver adnp_i2c_driver = { + .driver = { + .name = "gpio-adnp", + .owner = THIS_MODULE, + .of_match_table = adnp_of_match, + }, + .probe = adnp_i2c_probe, + .remove = adnp_i2c_remove, + .id_table = adnp_i2c_id, +}; +module_i2c_driver(adnp_i2c_driver); + +MODULE_DESCRIPTION("Avionic Design N-bit GPIO expander"); +MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); +MODULE_LICENSE("GPL"); |