From d4b7de612d193e1c8fdeee9902e5a582e746dfe9 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 5 Feb 2011 10:46:32 +0000 Subject: [PATCH] platform-drivers: x86: pmic: Use irq_chip buslock mechanism The set_type function of the pmic irq chip is a horrible hack. It schedules work because it cannot access the scu chip from the set_type function. That breaks the assumption, that the type is set after set_type has returned. irq_chips provide buslock functions to avoid the above. Convert the driver to use the proper model. Signed-off-by: Thomas Gleixner Cc: Feng Tang Cc: Matthew Garrett Cc: Alan Cox Cc: Alek Du Signed-off-by: Matthew Garrett --- drivers/platform/x86/intel_pmic_gpio.c | 80 ++++++++++++++-------------------- 1 file changed, 32 insertions(+), 48 deletions(-) diff --git a/drivers/platform/x86/intel_pmic_gpio.c b/drivers/platform/x86/intel_pmic_gpio.c index 9134d9d..df244c8 100644 --- a/drivers/platform/x86/intel_pmic_gpio.c +++ b/drivers/platform/x86/intel_pmic_gpio.c @@ -60,23 +60,18 @@ enum pmic_gpio_register { #define GPOSW_DOU 0x08 #define GPOSW_RDRV 0x30 +#define GPIO_UPDATE_TYPE 0x80000000 #define NUM_GPIO 24 -struct pmic_gpio_irq { - spinlock_t lock; - u32 trigger[NUM_GPIO]; - u32 dirty; - struct work_struct work; -}; - - struct pmic_gpio { + struct mutex buslock; struct gpio_chip chip; - struct pmic_gpio_irq irqtypes; void *gpiointr; int irq; unsigned irq_base; + unsigned int update_type; + u32 trigger_type; }; static void pmic_program_irqtype(int gpio, int type) @@ -92,37 +87,6 @@ static void pmic_program_irqtype(int gpio, int type) intel_scu_ipc_update_register(GPIO0 + gpio, 0x00, 0x10); }; -static void pmic_irqtype_work(struct work_struct *work) -{ - struct pmic_gpio_irq *t = - container_of(work, struct pmic_gpio_irq, work); - unsigned long flags; - int i; - u16 type; - - spin_lock_irqsave(&t->lock, flags); - /* As we drop the lock, we may need multiple scans if we race the - pmic_irq_type function */ - while (t->dirty) { - /* - * For each pin that has the dirty bit set send an IPC - * message to configure the hardware via the PMIC - */ - for (i = 0; i < NUM_GPIO; i++) { - if (!(t->dirty & (1 << i))) - continue; - t->dirty &= ~(1 << i); - /* We can't trust the array entry or dirty - once the lock is dropped */ - type = t->trigger[i]; - spin_unlock_irqrestore(&t->lock, flags); - pmic_program_irqtype(i, type); - spin_lock_irqsave(&t->lock, flags); - } - } - spin_unlock_irqrestore(&t->lock, flags); -} - static int pmic_gpio_direction_input(struct gpio_chip *chip, unsigned offset) { if (offset > 8) { @@ -190,20 +154,21 @@ static void pmic_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 1 << (offset - 16)); } +/* + * This is called from genirq with pg->buslock locked and + * irq_desc->lock held. We can not access the scu bus here, so we + * store the change and update in the bus_sync_unlock() function below + */ static int pmic_irq_type(struct irq_data *data, unsigned type) { struct pmic_gpio *pg = irq_data_get_irq_chip_data(data); u32 gpio = data->irq - pg->irq_base; - unsigned long flags; if (gpio >= pg->chip.ngpio) return -EINVAL; - spin_lock_irqsave(&pg->irqtypes.lock, flags); - pg->irqtypes.trigger[gpio] = type; - pg->irqtypes.dirty |= (1 << gpio); - spin_unlock_irqrestore(&pg->irqtypes.lock, flags); - schedule_work(&pg->irqtypes.work); + pg->trigger_type = type; + pg->update_type = gpio | GPIO_UPDATE_TYPE; return 0; } @@ -214,6 +179,26 @@ static int pmic_gpio_to_irq(struct gpio_chip *chip, unsigned offset) return pg->irq_base + offset; } +static void pmic_bus_lock(struct irq_data *data) +{ + struct pmic_gpio *pg = irq_data_get_irq_chip_data(data); + + mutex_lock(&pg->buslock); +} + +static void pmic_bus_sync_unlock(struct irq_data *data) +{ + struct pmic_gpio *pg = irq_data_get_irq_chip_data(data); + + if (pg->update_type) { + unsigned int gpio = pg->update_type & ~GPIO_UPDATE_TYPE; + + pmic_program_irqtype(gpio, pg->trigger_type); + pg->update_type = 0; + } + mutex_unlock(&pg->buslock); +} + /* the gpiointr register is read-clear, so just do nothing. */ static void pmic_irq_unmask(struct irq_data *data) { } @@ -287,8 +272,7 @@ static int __devinit platform_pmic_gpio_probe(struct platform_device *pdev) pg->chip.can_sleep = 1; pg->chip.dev = dev; - INIT_WORK(&pg->irqtypes.work, pmic_irqtype_work); - spin_lock_init(&pg->irqtypes.lock); + mutex_init(&pg->buslock); pg->chip.dev = dev; retval = gpiochip_add(&pg->chip); -- 2.7.4