diff options
author | Thomas Gleixner <tglx@linutronix.de> | 2011-02-14 18:08:51 +0100 |
---|---|---|
committer | Grant Likely <grant.likely@secretlab.ca> | 2011-02-22 14:59:53 -0700 |
commit | 0ff56cd85a2c5104a36d84662b9180c219e8604e (patch) | |
tree | 2d8826a9743143402a8028a3a1c36f21ff5df755 /drivers/gpio | |
parent | 0b782531c038d4a4bded3fc1069c961b1f14f0de (diff) | |
download | linux-0ff56cd85a2c5104a36d84662b9180c219e8604e.tar.gz linux-0ff56cd85a2c5104a36d84662b9180c219e8604e.tar.bz2 linux-0ff56cd85a2c5104a36d84662b9180c219e8604e.zip |
gpio/sx150x: Do not access I2C from mask/unmask functions
irq_chip->irq_mask/unmask are called with interrupts disabled and
irq_desc->lock held. So we cannot access i2c from this context. That's
what irq_bus_sync_unlock() is for.
Store the masked information in the chip data structure and update the
i2c bus from the irq_bus_sync_unlock() callback.
This does not need a while(pending) loop because the update to this is
always serialized via the bus lock, so we never have more than one pin
update pending.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Gregory Bean <gbean@codeaurora.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Lennert Buytenhek <buytenh@secretlab.ca>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'drivers/gpio')
-rw-r--r-- | drivers/gpio/sx150x.c | 54 |
1 files changed, 37 insertions, 17 deletions
diff --git a/drivers/gpio/sx150x.c b/drivers/gpio/sx150x.c index e60be0015c9b..d2f874c3d3d5 100644 --- a/drivers/gpio/sx150x.c +++ b/drivers/gpio/sx150x.c @@ -25,6 +25,8 @@ #include <linux/workqueue.h> #include <linux/i2c/sx150x.h> +#define NO_UPDATE_PENDING -1 + struct sx150x_device_data { u8 reg_pullup; u8 reg_pulldn; @@ -47,8 +49,11 @@ struct sx150x_chip { const struct sx150x_device_data *dev_cfg; int irq_summary; int irq_base; + int irq_update; u32 irq_sense; - unsigned long irq_set_type_pending; + u32 irq_masked; + u32 dev_sense; + u32 dev_masked; struct irq_chip irq_chip; struct mutex lock; }; @@ -312,9 +317,8 @@ static void sx150x_irq_mask(struct irq_data *d) chip = container_of(ic, struct sx150x_chip, irq_chip); n = d->irq - chip->irq_base; - - sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1); - sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0); + chip->irq_masked |= (1 << n); + chip->irq_update = n; } static void sx150x_irq_unmask(struct irq_data *d) @@ -326,9 +330,8 @@ static void sx150x_irq_unmask(struct irq_data *d) chip = container_of(ic, struct sx150x_chip, irq_chip); n = d->irq - chip->irq_base; - sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0); - sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, - chip->irq_sense >> (n * 2)); + chip->irq_masked &= ~(1 << n); + chip->irq_update = n; } static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type) @@ -350,7 +353,7 @@ static int sx150x_irq_set_type(struct irq_data *d, unsigned int flow_type) chip->irq_sense &= ~(3UL << (n * 2)); chip->irq_sense |= val << (n * 2); - chip->irq_set_type_pending |= BIT(n); + chip->irq_update = n; return 0; } @@ -404,15 +407,29 @@ static void sx150x_irq_bus_sync_unlock(struct irq_data *d) chip = container_of(ic, struct sx150x_chip, irq_chip); - while (chip->irq_set_type_pending) { - n = __ffs(chip->irq_set_type_pending); - chip->irq_set_type_pending &= ~BIT(n); - if (!(irq_to_desc(n + chip->irq_base)->status & IRQ_MASKED)) - sx150x_write_cfg(chip, n, 2, - chip->dev_cfg->reg_sense, - chip->irq_sense >> (n * 2)); - } + if (chip->irq_update == NO_UPDATE_PENDING) + goto out; + + n = chip->irq_update; + chip->irq_update = NO_UPDATE_PENDING; + /* Avoid updates if nothing changed */ + if (chip->dev_sense == chip->irq_sense && + chip->dev_sense == chip->irq_masked) + goto out; + + chip->dev_sense = chip->irq_sense; + chip->dev_masked = chip->irq_masked; + + if (chip->irq_masked & (1 << n)) { + sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 1); + sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, 0); + } else { + sx150x_write_cfg(chip, n, 1, chip->dev_cfg->reg_irq_mask, 0); + sx150x_write_cfg(chip, n, 2, chip->dev_cfg->reg_sense, + chip->irq_sense >> (n * 2)); + } +out: mutex_unlock(&chip->lock); } @@ -445,8 +462,11 @@ static void sx150x_init_chip(struct sx150x_chip *chip, chip->irq_chip.irq_bus_sync_unlock = sx150x_irq_bus_sync_unlock; chip->irq_summary = -1; chip->irq_base = -1; + chip->irq_masked = ~0; chip->irq_sense = 0; - chip->irq_set_type_pending = 0; + chip->dev_masked = ~0; + chip->dev_sense = 0; + chip->irq_update = NO_UPDATE_PENDING; } static int sx150x_init_io(struct sx150x_chip *chip, u8 base, u16 cfg) |