The patch titled
gpio: add interrupt handling capability to max732x
has been added to the -mm tree. Its filename is
gpio-add-interrupt-handling-capability-to-max732x.patch
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------------------------------------------------------
Subject: gpio: add interrupt handling capability to max732x
From: Marc Zyngier <maz@xxxxxxxxxxxxxxx>
Most of the GPIO expanders supported by the max732x driver have interrupt
generation capability by reporting changes on input pins through an INT#
pin. This patch implements the irq_chip functionnality (edge detection
only).
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxxxxxxx>
Cc: Eric Miao <eric.y.miao@xxxxxxxxx>
Cc: Jebediah Huang <jebediah.huang@xxxxxxxxx>
Cc: David Brownell <david-b@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/gpio/Kconfig | 7
drivers/gpio/max732x.c | 355 ++++++++++++++++++++++++++++++++--
include/linux/i2c/max732x.h | 3
3 files changed, 346 insertions(+), 19 deletions(-)
diff -puN drivers/gpio/Kconfig~gpio-add-interrupt-handling-capability-to-max732x drivers/gpio/Kconfig
--- a/drivers/gpio/Kconfig~gpio-add-interrupt-handling-capability-to-max732x
+++ a/drivers/gpio/Kconfig
@@ -139,6 +139,13 @@ config GPIO_MAX732X
Board setup code must specify the model to use, and the start
number for these GPIOs.
+config GPIO_MAX732X_IRQ
+ bool "Interrupt controller support for MAX732x"
+ depends on GPIO_MAX732X=y && GENERIC_HARDIRQS
+ help
+ Say yes here to enable the max732x to be used as an interrupt
+ controller. It requires the driver to be built in the kernel.
+
config GPIO_PCA953X
tristate "PCA953x, PCA955x, TCA64xx, and MAX7310 I/O ports"
depends on I2C
diff -puN drivers/gpio/max732x.c~gpio-add-interrupt-handling-capability-to-max732x drivers/gpio/max732x.c
--- a/drivers/gpio/max732x.c~gpio-add-interrupt-handling-capability-to-max732x
+++ a/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_
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
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(struc
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
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(struc
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(struc
return 0;
out_failed:
+ max732x_irq_teardown(chip);
kfree(chip);
return ret;
}
@@ -352,6 +667,8 @@ static int __devexit max732x_remove(stru
return ret;
}
+ max732x_irq_teardown(chip);
+
/* unregister any dummy i2c_client */
if (chip->client_dummy)
i2c_unregister_device(chip->client_dummy);
diff -puN include/linux/i2c/max732x.h~gpio-add-interrupt-handling-capability-to-max732x include/linux/i2c/max732x.h
--- a/include/linux/i2c/max732x.h~gpio-add-interrupt-handling-capability-to-max732x
+++ a/include/linux/i2c/max732x.h
@@ -7,6 +7,9 @@ struct max732x_platform_data {
/* number of the first GPIO */
unsigned gpio_base;
+ /* interrupt base */
+ int irq_base;
+
void *context; /* param to setup/teardown */
int (*setup)(struct i2c_client *client,
_
Patches currently in -mm which might be from maz@xxxxxxxxxxxxxxx are
origin.patch
gpio-add-interrupt-handling-capability-to-max732x.patch
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