diff options
Diffstat (limited to 'drivers/gpio/gpio-pcf857x.c')
| -rw-r--r-- | drivers/gpio/gpio-pcf857x.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c index 076e236d0da..12e3e484d70 100644 --- a/drivers/gpio/gpio-pcf857x.c +++ b/drivers/gpio/gpio-pcf857x.c @@ -23,7 +23,12 @@ #include <linux/gpio.h> #include <linux/i2c.h> #include <linux/i2c/pcf857x.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> #include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> static const struct i2c_device_id pcf857x_id[] = { @@ -60,7 +65,12 @@ struct pcf857x { struct gpio_chip chip; struct i2c_client *client; struct mutex lock; /* protect 'out' */ + struct work_struct work; /* irq demux work */ + struct irq_domain *irq_domain; /* for irq demux */ + spinlock_t slock; /* protect irq demux */ unsigned out; /* software latch */ + unsigned status; /* current status */ + int irq; /* real irq number */ int (*write)(struct i2c_client *client, unsigned data); int (*read)(struct i2c_client *client); @@ -150,6 +160,100 @@ static void pcf857x_set(struct gpio_chip *chip, unsigned offset, int value) /*-------------------------------------------------------------------------*/ +static int pcf857x_to_irq(struct gpio_chip *chip, unsigned offset) +{ + struct pcf857x *gpio = container_of(chip, struct pcf857x, chip); + + return irq_create_mapping(gpio->irq_domain, offset); +} + +static void pcf857x_irq_demux_work(struct work_struct *work) +{ + struct pcf857x *gpio = container_of(work, + struct pcf857x, + work); + unsigned long change, i, status, flags; + + status = gpio->read(gpio->client); + + spin_lock_irqsave(&gpio->slock, flags); + + change = gpio->status ^ status; + for_each_set_bit(i, &change, gpio->chip.ngpio) + generic_handle_irq(irq_find_mapping(gpio->irq_domain, i)); + gpio->status = status; + + spin_unlock_irqrestore(&gpio->slock, flags); +} + +static irqreturn_t pcf857x_irq_demux(int irq, void *data) +{ + struct pcf857x *gpio = data; + + /* + * pcf857x can't read/write data here, + * since i2c data access might go to sleep. + */ + schedule_work(&gpio->work); + + return IRQ_HANDLED; +} + +static int pcf857x_irq_domain_map(struct irq_domain *domain, unsigned int virq, + irq_hw_number_t hw) +{ + irq_set_chip_and_handler(virq, + &dummy_irq_chip, + handle_level_irq); + return 0; +} + +static struct irq_domain_ops pcf857x_irq_domain_ops = { + .map = pcf857x_irq_domain_map, +}; + +static void pcf857x_irq_domain_cleanup(struct pcf857x *gpio) +{ + if (gpio->irq_domain) + irq_domain_remove(gpio->irq_domain); + + if (gpio->irq) + free_irq(gpio->irq, gpio); +} + +static int pcf857x_irq_domain_init(struct pcf857x *gpio, + struct pcf857x_platform_data *pdata, + struct device *dev) +{ + int status; + + gpio->irq_domain = irq_domain_add_linear(dev->of_node, + gpio->chip.ngpio, + &pcf857x_irq_domain_ops, + NULL); + if (!gpio->irq_domain) + goto fail; + + /* enable real irq */ + status = request_irq(pdata->irq, pcf857x_irq_demux, 0, + dev_name(dev), gpio); + if (status) + goto fail; + + /* enable gpio_to_irq() */ + INIT_WORK(&gpio->work, pcf857x_irq_demux_work); + gpio->chip.to_irq = pcf857x_to_irq; + gpio->irq = pdata->irq; + + return 0; + +fail: + pcf857x_irq_domain_cleanup(gpio); + return -EINVAL; +} + +/*-------------------------------------------------------------------------*/ + static int pcf857x_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -168,6 +272,7 @@ static int pcf857x_probe(struct i2c_client *client, return -ENOMEM; mutex_init(&gpio->lock); + spin_lock_init(&gpio->slock); gpio->chip.base = pdata ? pdata->gpio_base : -1; gpio->chip.can_sleep = 1; @@ -179,6 +284,15 @@ static int pcf857x_probe(struct i2c_client *client, gpio->chip.direction_output = pcf857x_output; gpio->chip.ngpio = id->driver_data; + /* enable gpio_to_irq() if platform has settings */ + if (pdata->irq) { + status = pcf857x_irq_domain_init(gpio, pdata, &client->dev); + if (status < 0) { + dev_err(&client->dev, "irq_domain init failed\n"); + goto fail; + } + } + /* NOTE: the OnSemi jlc1562b is also largely compatible with * these parts, notably for output. It has a low-resolution * DAC instead of pin change IRQs; and its inputs can be the @@ -248,6 +362,7 @@ static int pcf857x_probe(struct i2c_client *client, * all-ones reset state. Otherwise it flags pins to be driven low. */ gpio->out = pdata ? ~pdata->n_latch : ~0; + gpio->status = gpio->out; status = gpiochip_add(&gpio->chip); if (status < 0) @@ -278,6 +393,10 @@ static int pcf857x_probe(struct i2c_client *client, fail: dev_dbg(&client->dev, "probe error %d for '%s'\n", status, client->name); + + if (pdata->irq) + pcf857x_irq_domain_cleanup(gpio); + kfree(gpio); return status; } @@ -299,6 +418,9 @@ static int pcf857x_remove(struct i2c_client *client) } } + if (pdata->irq) + pcf857x_irq_domain_cleanup(gpio); + status = gpiochip_remove(&gpio->chip); if (status == 0) kfree(gpio); |