gpio: mcp23s08: Add irq functionality for i2c chips
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 with a mcp23017 chip on an arm based platform. v3: - be a bit more clear that the irq functionality is also available on spi versions of the chips, but the linux driver does not support this yet v2: - some more word about irq-mirror property in binding doc - use of_read_bool instead of of_find_property for "interrupt-contrller" and "irq-mirror" - cache the "interrupt-controller" for remove function - do set the irq-mirror bit only if device is marked as interrupt-controller - do create the irq mapping and setup of irq_desc of all possible interrupts in probe path instead of in gpio_to_irq - mark gpios as in use as interrupts in irq in irq_startup and unlock it in irq_shutdown - rename virq to child_irq - remove dev argument from mcp23s08_irq_setup function - move gpiochip_add before mcp23s08_irq_setup in probe path Signed-off-by: Lars Poeschel <poeschel@lemonage.de> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Lars Poeschel
Linus Walleij
parent
785acec3ee
commit
4e47f91bf7
3 changed files with 271 additions and 6 deletions
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@ -38,12 +38,38 @@ Required device specific properties (only for SPI chips):
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removed.
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- spi-max-frequency = The maximum frequency this chip is able to handle
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Example I2C:
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Optional properties:
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- #interrupt-cells : Should be two.
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- first cell is the pin number
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- second cell is used to specify flags.
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- interrupt-controller: Marks the device node as a interrupt controller.
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NOTE: The interrupt functionality is only supported for i2c versions of the
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chips. The spi chips can also do the interrupts, but this is not supported by
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the linux driver yet.
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Optional device specific properties:
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- microchip,irq-mirror: Sets the mirror flag in the IOCON register. Devices
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with two interrupt outputs (these are the devices ending with 17 and
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those that have 16 IOs) have two IO banks: IO 0-7 form bank 1 and
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IO 8-15 are bank 2. These chips have two different interrupt outputs:
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One for bank 1 and another for bank 2. If irq-mirror is set, both
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interrupts are generated regardless of the bank that an input change
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occured on. If it is not set, the interrupt are only generated for the
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bank they belong to.
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On devices with only one interrupt output this property is useless.
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Example I2C (with interrupt):
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gpiom1: gpio@20 {
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compatible = "microchip,mcp23017";
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gpio-controller;
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#gpio-cells = <2>;
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reg = <0x20>;
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interrupt-parent = <&gpio1>;
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interrupts = <17 IRQ_TYPE_LEVEL_LOW>;
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interrupt-controller;
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#interrupt-cells=<2>;
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microchip,irq-mirror;
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};
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Example SPI:
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@ -722,6 +722,7 @@ config GPIO_MCP23S08
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SPI/I2C driver for Microchip MCP23S08/MCP23S17/MCP23008/MCP23017
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I/O expanders.
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This provides a GPIO interface supporting inputs and outputs.
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The I2C versions of the chips can be used as interrupt-controller.
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config GPIO_MC33880
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tristate "Freescale MC33880 high-side/low-side switch"
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@ -1,5 +1,13 @@
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/*
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* MCP23S08 SPI/GPIO gpio expander driver
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* MCP23S08 SPI/I2C GPIO gpio expander driver
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*
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* The inputs and outputs of the mcp23s08, mcp23s17, mcp23008 and mcp23017 are
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* supported.
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* For the I2C versions of the chips (mcp23008 and mcp23017) generation of
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* interrupts is also supported.
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* The hardware of the SPI versions of the chips (mcp23s08 and mcp23s17) is
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* also capable of generating interrupts, but the linux driver does not
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* support that yet.
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*/
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#include <linux/kernel.h>
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@ -12,7 +20,8 @@
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#include <linux/spi/mcp23s08.h>
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#include <linux/slab.h>
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#include <asm/byteorder.h>
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#include <linux/of.h>
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#include <linux/interrupt.h>
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#include <linux/of_irq.h>
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#include <linux/of_device.h>
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/**
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@ -34,6 +43,7 @@
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#define MCP_DEFVAL 0x03
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#define MCP_INTCON 0x04
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#define MCP_IOCON 0x05
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# define IOCON_MIRROR (1 << 6)
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# define IOCON_SEQOP (1 << 5)
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# define IOCON_HAEN (1 << 3)
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# define IOCON_ODR (1 << 2)
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@ -57,8 +67,14 @@ struct mcp23s08 {
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u8 addr;
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u16 cache[11];
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u16 irq_rise;
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u16 irq_fall;
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int irq;
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bool irq_controller;
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/* lock protects the cached values */
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struct mutex lock;
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struct mutex irq_lock;
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struct irq_domain *irq_domain;
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struct gpio_chip chip;
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@ -77,6 +93,11 @@ struct mcp23s08_driver_data {
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struct mcp23s08 chip[];
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};
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/* This lock class tells lockdep that GPIO irqs are in a different
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* category than their parents, so it won't report false recursion.
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*/
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static struct lock_class_key gpio_lock_class;
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/*----------------------------------------------------------------------*/
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#if IS_ENABLED(CONFIG_I2C)
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@ -315,6 +336,195 @@ mcp23s08_direction_output(struct gpio_chip *chip, unsigned offset, int value)
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return status;
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}
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/*----------------------------------------------------------------------*/
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static irqreturn_t mcp23s08_irq(int irq, void *data)
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{
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struct mcp23s08 *mcp = data;
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int intcap, intf, i;
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unsigned int child_irq;
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mutex_lock(&mcp->lock);
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intf = mcp->ops->read(mcp, MCP_INTF);
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if (intf < 0) {
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mutex_unlock(&mcp->lock);
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return IRQ_HANDLED;
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}
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mcp->cache[MCP_INTF] = intf;
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intcap = mcp->ops->read(mcp, MCP_INTCAP);
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if (intcap < 0) {
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mutex_unlock(&mcp->lock);
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return IRQ_HANDLED;
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}
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mcp->cache[MCP_INTCAP] = intcap;
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mutex_unlock(&mcp->lock);
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for (i = 0; i < mcp->chip.ngpio; i++) {
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if ((BIT(i) & mcp->cache[MCP_INTF]) &&
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((BIT(i) & intcap & mcp->irq_rise) ||
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(mcp->irq_fall & ~intcap & BIT(i)))) {
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child_irq = irq_find_mapping(mcp->irq_domain, i);
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handle_nested_irq(child_irq);
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}
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}
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return IRQ_HANDLED;
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}
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static int mcp23s08_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
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{
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struct mcp23s08 *mcp = container_of(chip, struct mcp23s08, chip);
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return irq_find_mapping(mcp->irq_domain, offset);
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}
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static void mcp23s08_irq_mask(struct irq_data *data)
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{
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struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
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unsigned int pos = data->hwirq;
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mcp->cache[MCP_GPINTEN] &= ~BIT(pos);
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}
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static void mcp23s08_irq_unmask(struct irq_data *data)
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{
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struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
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unsigned int pos = data->hwirq;
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mcp->cache[MCP_GPINTEN] |= BIT(pos);
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}
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static int mcp23s08_irq_set_type(struct irq_data *data, unsigned int type)
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{
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struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
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unsigned int pos = data->hwirq;
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int status = 0;
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if ((type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
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mcp->cache[MCP_INTCON] &= ~BIT(pos);
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mcp->irq_rise |= BIT(pos);
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mcp->irq_fall |= BIT(pos);
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} else if (type & IRQ_TYPE_EDGE_RISING) {
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mcp->cache[MCP_INTCON] &= ~BIT(pos);
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mcp->irq_rise |= BIT(pos);
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mcp->irq_fall &= ~BIT(pos);
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} else if (type & IRQ_TYPE_EDGE_FALLING) {
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mcp->cache[MCP_INTCON] &= ~BIT(pos);
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mcp->irq_rise &= ~BIT(pos);
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mcp->irq_fall |= BIT(pos);
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} else
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return -EINVAL;
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return status;
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}
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static void mcp23s08_irq_bus_lock(struct irq_data *data)
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{
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struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
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mutex_lock(&mcp->irq_lock);
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}
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static void mcp23s08_irq_bus_unlock(struct irq_data *data)
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{
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struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
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mutex_lock(&mcp->lock);
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mcp->ops->write(mcp, MCP_GPINTEN, mcp->cache[MCP_GPINTEN]);
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mcp->ops->write(mcp, MCP_DEFVAL, mcp->cache[MCP_DEFVAL]);
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mcp->ops->write(mcp, MCP_INTCON, mcp->cache[MCP_INTCON]);
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mutex_unlock(&mcp->lock);
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mutex_unlock(&mcp->irq_lock);
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}
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static unsigned int mcp23s08_irq_startup(struct irq_data *data)
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{
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struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
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if (gpio_lock_as_irq(&mcp->chip, data->hwirq))
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dev_err(mcp->chip.dev,
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"unable to lock HW IRQ %lu for IRQ usage\n",
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data->hwirq);
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mcp23s08_irq_unmask(data);
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return 0;
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}
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static void mcp23s08_irq_shutdown(struct irq_data *data)
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{
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struct mcp23s08 *mcp = irq_data_get_irq_chip_data(data);
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mcp23s08_irq_mask(data);
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gpio_unlock_as_irq(&mcp->chip, data->hwirq);
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}
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static struct irq_chip mcp23s08_irq_chip = {
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.name = "gpio-mcp23xxx",
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.irq_mask = mcp23s08_irq_mask,
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.irq_unmask = mcp23s08_irq_unmask,
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.irq_set_type = mcp23s08_irq_set_type,
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.irq_bus_lock = mcp23s08_irq_bus_lock,
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.irq_bus_sync_unlock = mcp23s08_irq_bus_unlock,
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.irq_startup = mcp23s08_irq_startup,
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.irq_shutdown = mcp23s08_irq_shutdown,
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};
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static int mcp23s08_irq_setup(struct mcp23s08 *mcp)
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{
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struct gpio_chip *chip = &mcp->chip;
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int err, irq, j;
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mutex_init(&mcp->irq_lock);
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mcp->irq_domain = irq_domain_add_linear(chip->of_node, chip->ngpio,
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&irq_domain_simple_ops, mcp);
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if (!mcp->irq_domain)
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return -ENODEV;
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err = devm_request_threaded_irq(chip->dev, mcp->irq, NULL, mcp23s08_irq,
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IRQF_TRIGGER_LOW | IRQF_ONESHOT,
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dev_name(chip->dev), mcp);
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if (err != 0) {
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dev_err(chip->dev, "unable to request IRQ#%d: %d\n",
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mcp->irq, err);
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return err;
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}
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chip->to_irq = mcp23s08_gpio_to_irq;
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for (j = 0; j < mcp->chip.ngpio; j++) {
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irq = irq_create_mapping(mcp->irq_domain, j);
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irq_set_lockdep_class(irq, &gpio_lock_class);
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irq_set_chip_data(irq, mcp);
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irq_set_chip(irq, &mcp23s08_irq_chip);
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irq_set_nested_thread(irq, true);
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#ifdef CONFIG_ARM
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set_irq_flags(irq, IRQF_VALID);
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#else
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irq_set_noprobe(irq);
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#endif
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}
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return 0;
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}
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static void mcp23s08_irq_teardown(struct mcp23s08 *mcp)
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{
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unsigned int irq, i;
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free_irq(mcp->irq, mcp);
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for (i = 0; i < mcp->chip.ngpio; i++) {
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irq = irq_find_mapping(mcp->irq_domain, i);
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if (irq > 0)
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irq_dispose_mapping(irq);
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}
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irq_domain_remove(mcp->irq_domain);
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}
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/*----------------------------------------------------------------------*/
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#ifdef CONFIG_DEBUG_FS
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@ -370,10 +580,11 @@ static void mcp23s08_dbg_show(struct seq_file *s, struct gpio_chip *chip)
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/*----------------------------------------------------------------------*/
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static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
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void *data, unsigned addr,
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unsigned type, unsigned base, unsigned pullups)
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void *data, unsigned addr, unsigned type,
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unsigned base, unsigned pullups)
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{
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int status;
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bool mirror = false;
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mutex_init(&mcp->lock);
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@ -432,13 +643,25 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
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/* verify MCP_IOCON.SEQOP = 0, so sequential reads work,
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* and MCP_IOCON.HAEN = 1, so we work with all chips.
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*/
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status = mcp->ops->read(mcp, MCP_IOCON);
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if (status < 0)
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goto fail;
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if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN)) {
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mcp->irq_controller = of_property_read_bool(mcp->chip.of_node,
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"interrupt-controller");
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if (mcp->irq && mcp->irq_controller && (type == MCP_TYPE_017))
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mirror = of_property_read_bool(mcp->chip.of_node,
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"microchip,irq-mirror");
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if ((status & IOCON_SEQOP) || !(status & IOCON_HAEN) || mirror) {
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/* mcp23s17 has IOCON twice, make sure they are in sync */
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status &= ~(IOCON_SEQOP | (IOCON_SEQOP << 8));
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status |= IOCON_HAEN | (IOCON_HAEN << 8);
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status &= ~(IOCON_INTPOL | (IOCON_INTPOL << 8));
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if (mirror)
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status |= IOCON_MIRROR | (IOCON_MIRROR << 8);
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status = mcp->ops->write(mcp, MCP_IOCON, status);
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if (status < 0)
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goto fail;
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@ -470,6 +693,16 @@ static int mcp23s08_probe_one(struct mcp23s08 *mcp, struct device *dev,
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}
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status = gpiochip_add(&mcp->chip);
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if (status < 0)
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goto fail;
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if (mcp->irq && mcp->irq_controller) {
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status = mcp23s08_irq_setup(mcp);
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if (status) {
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mcp23s08_irq_teardown(mcp);
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goto fail;
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}
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}
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fail:
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if (status < 0)
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dev_dbg(dev, "can't setup chip %d, --> %d\n",
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@ -546,6 +779,7 @@ static int mcp230xx_probe(struct i2c_client *client,
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if (match || !pdata) {
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base = -1;
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pullups = 0;
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client->irq = irq_of_parse_and_map(client->dev.of_node, 0);
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} else {
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if (!gpio_is_valid(pdata->base)) {
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dev_dbg(&client->dev, "invalid platform data\n");
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@ -559,6 +793,7 @@ static int mcp230xx_probe(struct i2c_client *client,
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if (!mcp)
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return -ENOMEM;
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mcp->irq = client->irq;
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status = mcp23s08_probe_one(mcp, &client->dev, client, client->addr,
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id->driver_data, base, pullups);
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if (status)
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@ -579,6 +814,9 @@ static int mcp230xx_remove(struct i2c_client *client)
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struct mcp23s08 *mcp = i2c_get_clientdata(client);
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int status;
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if (client->irq && mcp->irq_controller)
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mcp23s08_irq_teardown(mcp);
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status = gpiochip_remove(&mcp->chip);
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if (status == 0)
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kfree(mcp);
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