From: Lars Poeschel <poeschel@xxxxxxxxxxx> This adds interrupt functionality for i2c chips to the driver. They can act as a interrupt-controller and generate interrupts, if the inputs change. This is tested on a mcp23017 chip. Signed-off-by: Lars Poeschel <poeschel@xxxxxxxxxxx> --- .../devicetree/bindings/gpio/gpio-mcp23s08.txt | 21 +- drivers/gpio/Kconfig | 1 + drivers/gpio/gpio-mcp23s08.c | 220 ++++++++++++++++++++- 3 files changed, 236 insertions(+), 6 deletions(-) diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt index daa3017..b8376f3 100644 --- a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt +++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt @@ -38,12 +38,31 @@ Required device specific properties (only for SPI chips): removed. - spi-max-frequency = The maximum frequency this chip is able to handle -Example I2C: +Optional properties: +- #interrupt-cells : Should be two. + - first cell is the pin number + - second cell is used to specify flags. +- interrupt-controller: Marks the device node as a interrupt controller. +NOTE: The interrupt functionality is only supported for i2c versions of the +chips yet. + +Optional device specific properties: +- microchip,irq-mirror: Sets the mirror flag in the IOCON register. This causes + devices with two interrupt outputs to always trigger both interrupt + outputs regardless where the interrupt happened. + +Example I2C (with interrupt): gpiom1: gpio@20 { compatible = "microchip,mcp23017"; gpio-controller; #gpio-cells = <2>; reg = <0x20>; + + interrupt-parent = <&gpio1>; + interrupts = <17 IRQ_TYPE_LEVEL_LOW>; + interrupt-controller; + #interrupt-cells=<2>; + microchip,irq-mirror; }; Example SPI: diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 0f04444..9fe782a 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -697,6 +697,7 @@ config GPIO_MCP23S08 SPI/I2C driver for Microchip MCP23S08/MCP23S17/MCP23008/MCP23017 I/O expanders. This provides a GPIO interface supporting inputs and outputs. + The I2C versions of the chips can be used as interrupt-controller. config GPIO_MC33880 tristate "Freescale MC33880 high-side/low-side switch" diff --git a/drivers/gpio/gpio-mcp23s08.c b/drivers/gpio/gpio-mcp23s08.c index 2deb0c5..df32b90 100644 --- a/drivers/gpio/gpio-mcp23s08.c +++ b/drivers/gpio/gpio-mcp23s08.c @@ -1,5 +1,10 @@ /* - * MCP23S08 SPI/GPIO gpio expander driver + * MCP23S08 SPI/I2C GPIO gpio expander driver + * + * The inputs and outputs of the mcp23s08, mcp23s17, mcp23008 and mcp23017 are + * supported. + * For the I2C versions of the chips (mcp23008 and mcp23017) generation of + * interrupts is also supported. */ #include <linux/kernel.h> @@ -12,7 +17,8 @@ #include <linux/spi/mcp23s08.h> #include <linux/slab.h> #include <asm/byteorder.h> -#include <linux/of.h> +#include <linux/interrupt.h> +#include <linux/of_irq.h> #include <linux/of_device.h> /** @@ -34,6 +40,7 @@ #define MCP_DEFVAL 0x03 #define MCP_INTCON 0x04 #define MCP_IOCON 0x05 +# define IOCON_MIRROR (1 << 6) # define IOCON_SEQOP (1 << 5) # define IOCON_HAEN (1 << 3) # define IOCON_ODR (1 << 2) @@ -57,8 +64,13 @@ struct mcp23s08 { u8 addr; u16 cache[11]; + u16 irq_rise; + u16 irq_fall; + int irq; /* lock protects the cached values */ struct mutex lock; + struct mutex irq_lock; + struct irq_domain *irq_domain; struct gpio_chip chip; @@ -316,6 +328,179 @@ mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value) } /*----------------------------------------------------------------------*/ +static irqreturn_t mcp23s08_irq(int irq, void *data) +{ + struct mcp23s08 *mcp = data; + int intcap, intf, i; + unsigned int virq; + + mutex_lock(&mcp->lock); + intf = mcp->ops->read(mcp, MCP_INTF); + if (intf < 0) { + mutex_unlock(&mcp->lock); + return IRQ_HANDLED; + } + + mcp->cache[MCP_INTF] = intf; + + intcap = mcp->ops->read(mcp, MCP_INTCAP); + if (intcap < 0) { + mutex_unlock(&mcp->lock); + return IRQ_HANDLED; + } + + mcp->cache[MCP_INTCAP] = intcap; + mutex_unlock(&mcp->lock); + + + for (i = 0; i < mcp->chip.ngpio; i++) { + if ((BIT(i) & mcp->cache[MCP_INTF]) && + ((BIT(i) & intcap & mcp->irq_rise) || + (mcp->irq_fall & ~intcap & BIT(i)))) { + virq = irq_find_mapping(mcp->irq_domain, i); + handle_nested_irq(virq); + } + } + + return IRQ_HANDLED; +} + +static int mcp23s08_gpio_to_irq(struct gpio_chip *chip, unsigned offset) +{ + struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip); + + return irq_create_mapping(mcp->irq_domain, offset); +} + +static void mcp23s08_irq_mask(struct irq_data *data) +{ + struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data); + unsigned int pos = data->hwirq; + + mcp->cache[MCP_GPINTEN] &= ~BIT(pos); +} + +static void mcp23s08_irq_unmask(struct irq_data *data) +{ + struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data); + unsigned int pos = data->hwirq; + + mcp->cache[MCP_GPINTEN] |= BIT(pos); +} + +static int mcp23s08_irq_set_type(struct irq_data *data, unsigned int type) +{ + struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data); + unsigned int pos = data->hwirq; + int status = 0; + + if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) { + mcp->cache[MCP_INTCON] &= ~BIT(pos); + mcp->irq_rise |= BIT(pos); + mcp->irq_fall |= BIT(pos); + } else if (type & IRQ_TYPE_EDGE_RISING) { + mcp->cache[MCP_INTCON] &= ~BIT(pos); + mcp->irq_rise |= BIT(pos); + mcp->irq_fall &= ~BIT(pos); + } else if (type & IRQ_TYPE_EDGE_FALLING) { + mcp->cache[MCP_INTCON] &= ~BIT(pos); + mcp->irq_rise &= ~BIT(pos); + mcp->irq_fall |= BIT(pos); + } else + return -EINVAL; + + return status; +} + +static void mcp23s08_irq_bus_lock(struct irq_data *data) +{ + struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data); + + mutex_lock(&mcp->irq_lock); +} + +static void mcp23s08_irq_bus_unlock(struct irq_data *data) +{ + struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data); + + mutex_lock(&mcp->lock); + mcp->ops->write(mcp, MCP_GPINTEN, mcp->cache[MCP_GPINTEN]); + mcp->ops->write(mcp, MCP_DEFVAL, mcp->cache[MCP_DEFVAL]); + mcp->ops->write(mcp, MCP_INTCON, mcp->cache[MCP_INTCON]); + mutex_unlock(&mcp->lock); + mutex_unlock(&mcp->irq_lock); +} + +static struct irq_chip mcp23s08_irq_chip = { + .name = "gpio-mcp23xxx", + .irq_mask = mcp23s08_irq_mask, + .irq_unmask = mcp23s08_irq_unmask, + .irq_set_type = mcp23s08_irq_set_type, + .irq_bus_lock = mcp23s08_irq_bus_lock, + .irq_bus_sync_unlock = mcp23s08_irq_bus_unlock, +}; + +static int mcp23s08_irq_map(struct irq_domain *domain, unsigned int irq, + irq_hw_number_t hwirq) +{ + irq_set_chip_data(irq, domain->host_data); + irq_set_chip(irq, &mcp23s08_irq_chip); + irq_set_nested_thread(irq, true); + +#ifdef CONFIG_ARM + set_irq_flags(irq, IRQF_VALID); +#else + irq_set_noprobe(irq); +#endif + return 0; +} + +static const struct irq_domain_ops mcp23s08_irq_domain_ops = { + .map = mcp23s08_irq_map, + .xlate = irq_domain_xlate_twocell, +}; + +static int mcp23s08_irq_setup(struct mcp23s08 *mcp, struct device *dev) +{ + struct gpio_chip *chip = &mcp->chip; + int err; + + mutex_init(&mcp->irq_lock); + + mcp->irq_domain = irq_domain_add_linear(chip->of_node, chip->ngpio, + &mcp23s08_irq_domain_ops, mcp); + if (!mcp->irq_domain) + return -ENODEV; + + err = devm_request_threaded_irq(dev, mcp->irq, NULL, mcp23s08_irq, + IRQF_TRIGGER_LOW | IRQF_ONESHOT, + dev_name(chip->dev), mcp); + if (err != 0) { + dev_err(chip->dev, "unable to request IRQ#%d: %d\n", + mcp->irq, err); + return err; + } + + chip->to_irq = mcp23s08_gpio_to_irq; + return 0; +} + +static void mcp23s08_irq_teardown(struct mcp23s08 *mcp) +{ + unsigned int irq, i; + + free_irq(mcp->irq, mcp); + + for (i = 0; i < mcp->chip.ngpio; i++) { + irq = irq_find_mapping(mcp->irq_domain, i); + if (irq > 0) + irq_dispose_mapping(irq); + } + + irq_domain_remove(mcp->irq_domain); +} + +/*----------------------------------------------------------------------*/ #ifdef CONFIG_DEBUG_FS @@ -370,10 +555,11 @@ done: /*----------------------------------------------------------------------*/ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev, - void *data, unsigned addr, - unsigned type, unsigned base, unsigned pullups) + void *data, unsigned addr, unsigned type, + unsigned base, unsigned pullups) { int status; + struct property *mirror; mutex_init(&mcp->lock); @@ -432,13 +618,21 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev, /* verify MCP_IOCON.SEQOP = 0, so sequential reads work, * and MCP_IOCON.HAEN = 1, so we work with all chips. */ + status = mcp->ops->read(mcp, MCP_IOCON); if (status < 0) goto fail; - if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) { + + mirror = of_find_property(mcp->chip.of_node, + "microchip,irq-mirror", NULL); + if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror) { /* mcp23s17 has IOCON twice, make sure they are in sync */ status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8)); status |= IOCON_HAEN | (IOCON_HAEN << 8); + status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8)); + if (mirror) + status |= IOCON_MIRROR | (IOCON_MIRROR << 8); + status = mcp->ops->write(mcp, MCP_IOCON, status); if (status < 0) goto fail; @@ -469,7 +663,17 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev, goto fail; } + if (mcp->irq && + of_find_property(mcp->chip.of_node, "interrupt-controller", NULL)) { + status = mcp23s08_irq_setup(mcp, dev); + if (status) { + mcp23s08_irq_teardown(mcp); + goto fail; + } + } + status = gpiochip_add(&mcp->chip); + fail: if (status < 0) dev_dbg(dev, "can't setup chip %d, --> %d\n", @@ -546,6 +750,7 @@ static int mcp230xx_probe(struct i2c_client *client, if (match || !pdata) { base = -1; pullups = 0; + client->irq = irq_of_parse_and_map(client->dev.of_node, 0); } else { if (!gpio_is_valid(pdata->base)) { dev_dbg(&client->dev, "invalid platform data\n"); @@ -559,6 +764,7 @@ static int mcp230xx_probe(struct i2c_client *client, if (!mcp) return -ENOMEM; + mcp->irq = client->irq; status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr, id->driver_data, base, pullups); if (status) @@ -583,6 +789,10 @@ static int mcp230xx_remove(struct i2c_client *client) if (status == 0) kfree(mcp); + if (client->irq && + of_find_property(mcp->chip.of_node, "interrupt-controller", NULL)) + mcp23s08_irq_teardown(mcp); + return status; } -- 1.8.5.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html