From: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Replace twl4030 GPIO IRQ handling with generic SIH support.
No change in functionality; but there's now one less kernel
thread tied up supporting this chip.
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/gpio/twl4030-gpio.c | 423 ++++--------------------------------------
1 file changed, 42 insertions(+), 381 deletions(-)
--- a/drivers/gpio/twl4030-gpio.c
+++ b/drivers/gpio/twl4030-gpio.c
@@ -51,22 +51,8 @@
*/
-static inline void activate_irq(int irq)
-{
-#ifdef CONFIG_ARM
- /* ARM requires an extra step to clear IRQ_NOREQUEST, which it
- * sets on behalf of every irq_chip. Also sets IRQ_NOPROBE.
- */
- set_irq_flags(irq, IRQF_VALID);
-#else
- /* same effect on other architectures */
- set_irq_noprobe(irq);
-#endif
-}
-
static struct gpio_chip twl_gpiochip;
static int twl4030_gpio_irq_base;
-static int twl4030_gpio_irq_end;
/* genirq interfaces are not available to modules */
#ifdef MODULE
@@ -89,133 +75,7 @@ static DEFINE_MUTEX(gpio_lock);
/* store usage of each GPIO. - each bit represents one GPIO */
static unsigned int gpio_usage_count;
-/* protect what irq_chip modifies through its helper task */
-static DEFINE_SPINLOCK(gpio_spinlock);
-
-/* shadow the imr register; updates are delayed */
-static u32 gpio_imr_shadow;
-static bool gpio_pending_mask;
-
-/* bitmask of requests to set gpio irq trigger type */
-static unsigned int gpio_pending_trigger;
-
-/* pointer to helper thread */
-static struct task_struct *gpio_helper_thread;
-
-/*
- * Helper functions to read and write the GPIO ISR and IMR registers as
- * 32-bit integers. Functions return 0 on success, non-zero otherwise.
- * The caller must hold gpio_lock.
- */
-
-/* NOTE: only the IRQ dispatcher may read ISR; reading it has
- * side effects, because of the clear-on-read mechanism (COR=1).
- */
-static int gpio_read_isr(unsigned int *isr)
-{
- int ret;
-
- *isr = 0;
- ret = twl4030_i2c_read(TWL4030_MODULE_GPIO, (u8 *) isr,
- REG_GPIO_ISR1A, 3);
- le32_to_cpup(isr);
- *isr &= GPIO_32_MASK;
-
- return ret;
-}
-
-/* IMR is written only during initialization and
- * by request of the irq_chip code.
- */
-static int gpio_write_imr(unsigned int imr)
-{
- imr &= GPIO_32_MASK;
- /*
- * The buffer passed to the twl4030_i2c_write() routine must have an
- * extra byte at the beginning reserved for its internal use.
- */
- imr <<= 8;
- imr = cpu_to_le32(imr);
- return twl4030_i2c_write(TWL4030_MODULE_GPIO, (u8 *) &imr,
- REG_GPIO_IMR1A, 3);
-}
-
-/*
- * These are the irqchip methods for the TWL4030 GPIO interrupts.
- * Our IRQ handle method doesn't call these, but they will be called by
- * other routines such as setup_irq() and enable_irq(). They are called
- * with cpu interrupts disabled and with a lock on the irq_desc.lock
- * spinlock. This complicates matters, because accessing the TWL4030 GPIO
- * interrupt controller requires I2C bus transactions that can't be initiated
- * in this context. Our solution is to defer accessing the interrupt
- * controller to a kernel thread.
- */
-
-static void twl4030_gpio_irq_ack(unsigned int irq)
-{
- /* NOP -- dispatcher acks when it reads ISR */
-}
-
-static void twl4030_gpio_irq_mask(unsigned int irq)
-{
- int gpio = irq - twl4030_gpio_irq_base;
- u32 mask = 1 << gpio;
- unsigned long flags;
-
- spin_lock_irqsave(&gpio_spinlock, flags);
- gpio_pending_mask = true;
- gpio_imr_shadow |= mask;
- if (gpio_helper_thread && gpio_helper_thread->state != TASK_RUNNING)
- wake_up_process(gpio_helper_thread);
- spin_unlock_irqrestore(&gpio_spinlock, flags);
-}
-
-static void twl4030_gpio_irq_unmask(unsigned int irq)
-{
- int gpio = irq - twl4030_gpio_irq_base;
- u32 mask = 1 << gpio;
- unsigned long flags;
-
- spin_lock_irqsave(&gpio_spinlock, flags);
- gpio_pending_mask = true;
- gpio_imr_shadow &= ~mask;
- if (gpio_helper_thread && gpio_helper_thread->state != TASK_RUNNING)
- wake_up_process(gpio_helper_thread);
- spin_unlock_irqrestore(&gpio_spinlock, flags);
-}
-
-static int twl4030_gpio_irq_set_type(unsigned int irq, unsigned trigger)
-{
- struct irq_desc *desc = irq_desc + irq;
- int gpio = irq - twl4030_gpio_irq_base;
- unsigned long flags;
-
- trigger &= IRQ_TYPE_SENSE_MASK;
- if (trigger & ~IRQ_TYPE_EDGE_BOTH)
- return -EINVAL;
- if ((desc->status & IRQ_TYPE_SENSE_MASK) == trigger)
- return 0;
-
- desc->status &= ~IRQ_TYPE_SENSE_MASK;
- desc->status |= trigger;
-
- spin_lock_irqsave(&gpio_spinlock, flags);
- gpio_pending_trigger |= (1 << gpio);
- if (gpio_helper_thread && gpio_helper_thread->state != TASK_RUNNING)
- wake_up_process(gpio_helper_thread);
- spin_unlock_irqrestore(&gpio_spinlock, flags);
-
- return 0;
-}
-
-static struct irq_chip twl4030_gpio_irq_chip = {
- .name = "twl4030",
- .ack = twl4030_gpio_irq_ack,
- .mask = twl4030_gpio_irq_mask,
- .unmask = twl4030_gpio_irq_unmask,
- .set_type = twl4030_gpio_irq_set_type,
-};
-
+/*----------------------------------------------------------------------*/
/*
* To configure TWL4030 GPIO module registers
@@ -355,35 +215,6 @@ int twl4030_get_gpio_datain(int gpio)
}
EXPORT_SYMBOL(twl4030_get_gpio_datain);
-static int twl4030_set_gpio_edge_ctrl(int gpio, int edge)
-{
- u8 c_bnk = gpio >> 2;
- u8 c_off = (gpio & 0x3) * 2;
- u8 c_msk = 0;
- u8 reg = 0;
- u8 base = 0;
- int ret = 0;
-
- base = REG_GPIO_EDR1 + c_bnk;
-
- if (edge & IRQ_TYPE_EDGE_RISING)
- c_msk |= BIT(c_off + 1);
- if (edge & IRQ_TYPE_EDGE_FALLING)
- c_msk |= BIT(c_off);
-
- mutex_lock(&gpio_lock);
- ret = gpio_twl4030_read(base);
- if (ret >= 0) {
- /* clear the previous rising/falling values */
- reg = (u8) ret;
- reg &= ~(0x3 << c_off);
- reg |= c_msk;
- ret = gpio_twl4030_write(base, reg);
- }
- mutex_unlock(&gpio_lock);
- return ret;
-}
-
/*
* Configure debounce timing value for a GPIO pin on TWL4030
*/
@@ -450,105 +281,6 @@ int twl4030_set_gpio_card_detect(int gpi
}
#endif
-/* MODULE FUNCTIONS */
-
-/*
- * gpio_helper_thread() is a kernel thread that is awakened by irq_chip
- * methods to update IRQ masks and trigger modes.
- *
- * We must do this in a thread rather than in irq_chip methods because of the
- * need to access the TWL4030 via the I2C bus. Note that we don't need to be
- * concerned about race conditions where the request to unmask a GPIO interrupt
- * has already been cancelled before this thread does the unmasking. If a GPIO
- * interrupt is improperly unmasked, then the IRQ handler for it will mask it
- * when an interrupt occurs.
- */
-static int twl4030_gpio_helper_thread(void *dev)
-{
- current->flags |= PF_NOFREEZE;
-
- while (!kthread_should_stop()) {
- int irq;
- bool do_mask;
- u32 local_imr;
- unsigned int gpio_trigger;
-
- spin_lock_irq(&gpio_spinlock);
-
- do_mask = gpio_pending_mask;
- gpio_pending_mask = false;
- local_imr = gpio_imr_shadow;
-
- gpio_trigger = gpio_pending_trigger;
- gpio_pending_trigger = 0;
-
- spin_unlock_irq(&gpio_spinlock);
-
- if (do_mask) {
- int status = gpio_write_imr(local_imr);
-
- if (status)
- dev_err(dev, "write IMR err %d\n", status);
- }
-
- for (irq = twl4030_gpio_irq_base;
- gpio_trigger;
- gpio_trigger >>= 1, irq++) {
- struct irq_desc *desc;
- unsigned type;
-
- if (!(gpio_trigger & 0x1))
- continue;
-
- desc = irq_desc + irq;
- spin_lock_irq(&desc->lock);
- type = desc->status & IRQ_TYPE_SENSE_MASK;
- spin_unlock_irq(&desc->lock);
-
- twl4030_set_gpio_edge_ctrl(irq - twl4030_gpio_irq_base,
- type);
- }
-
- spin_lock_irq(&gpio_spinlock);
- if (!gpio_pending_mask && !gpio_pending_trigger)
- set_current_state(TASK_INTERRUPTIBLE);
- spin_unlock_irq(&gpio_spinlock);
-
- schedule();
- }
- set_current_state(TASK_RUNNING);
- return 0;
-}
-
-/*
- * do_twl4030_gpio_module_irq() is the desc->handle method for the twl4030 gpio
- * module interrupt. It executes in kernel thread context.
- * This is a chained interrupt, so there is no desc->action method for it.
- * We query the gpio module interrupt controller in the twl4030 to determine
- * which gpio lines are generating interrupt requests, and then call the
- * desc->handle method for each gpio that needs service.
- * On entry, cpu interrupts are disabled.
- */
-static void do_twl4030_gpio_module_irq(unsigned int irq, irq_desc_t *desc)
-{
- int gpio_irq;
- unsigned int gpio_isr;
-
- /* PIH irqs like this can't be individually masked or acked ...
- * so we don't even call the PIH irq_chip stub methods.
- */
- local_irq_enable();
- if (gpio_read_isr(&gpio_isr))
- gpio_isr = 0;
- local_irq_disable();
-
- for (gpio_irq = twl4030_gpio_irq_base; 0 != gpio_isr;
- gpio_isr >>= 1, gpio_irq++) {
- if (gpio_isr & 0x1)
- generic_handle_irq(gpio_irq);
- }
-}
-
/*----------------------------------------------------------------------*/
static int twl_direction_in(struct gpio_chip *chip, unsigned offset)
@@ -576,8 +308,9 @@ static void twl_set(struct gpio_chip *ch
static int twl_to_irq(struct gpio_chip *chip, unsigned offset)
{
- /* NOTE: assumes IRQs are set up ... */
- return twl4030_gpio_irq_base + offset;
+ return twl4030_gpio_irq_base
+ ? (twl4030_gpio_irq_base + offset)
+ : -EINVAL;
}
static struct gpio_chip twl_gpiochip = {
@@ -624,111 +357,52 @@ static int __devinit gpio_twl4030_probe(
{
struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
int ret;
- int irq = 0;
- /* All GPIO interrupts are initially masked */
- gpio_pending_mask = false;
- gpio_imr_shadow = GPIO_32_MASK;
- ret = gpio_write_imr(gpio_imr_shadow);
-
- twl4030_gpio_irq_base = pdata->irq_base;
- twl4030_gpio_irq_end = pdata->irq_end;
-
- if ((twl4030_gpio_irq_end - twl4030_gpio_irq_base) > 0) {
+ /* maybe setup IRQs */
+ if (pdata->irq_base) {
if (is_module()) {
dev_err(&pdev->dev,
"can't dispatch IRQs from modules\n");
goto no_irqs;
}
- if (twl4030_gpio_irq_end > NR_IRQS) {
- dev_err(&pdev->dev,
- "last IRQ is too large: %d\n",
- twl4030_gpio_irq_end);
- return -EINVAL;
- }
- } else {
- dev_notice(&pdev->dev,
- "no IRQs being dispatched\n");
- goto no_irqs;
- }
-
- if (!ret) {
- /*
- * Create a kernel thread to handle deferred operations on gpio
- * interrupts.
- */
- gpio_helper_thread = kthread_create(twl4030_gpio_helper_thread,
- &pdev->dev, "twl4030 gpio");
- if (!gpio_helper_thread) {
- dev_err(&pdev->dev,
- "could not create helper thread!\n");
- ret = -ENOMEM;
- }
- }
-
- if (!ret) {
- /* install an irq handler for each of the gpio interrupts */
- for (irq = twl4030_gpio_irq_base; irq < twl4030_gpio_irq_end;
- irq++) {
- set_irq_chip_and_handler(irq, &twl4030_gpio_irq_chip,
- handle_edge_irq);
- activate_irq(irq);
- }
-
- /* gpio module IRQ */
- irq = platform_get_irq(pdev, 0);
-
- /* COR=1 means irqs are acked by reading ISR
- * PENDDIS=0 means pending events enabled
- * EXCLEN=0 means route to both irq lines
- */
- gpio_twl4030_write(REG_GPIO_SIH_CTRL,
- TWL4030_SIH_CTRL_COR_MASK);
-
- /*
- * Install an irq handler to demultiplex the gpio module
- * interrupt.
- */
- set_irq_chained_handler(irq, do_twl4030_gpio_module_irq);
- wake_up_process(gpio_helper_thread);
-
- dev_info(&pdev->dev, "IRQ %d chains IRQs %d..%d\n", irq,
- twl4030_gpio_irq_base, twl4030_gpio_irq_end - 1);
+ ret = twl4030_sih_setup(TWL4030_MODULE_GPIO);
+ if (ret < 0)
+ return ret;
+ WARN_ON(ret != pdata->irq_base);
+ twl4030_gpio_irq_base = ret;
}
no_irqs:
- if (!ret) {
- /*
- * NOTE: boards may waste power if they don't set pullups
- * and pulldowns correctly ... default for non-ULPI pins is
- * pulldown, and some other pins may have external pullups
- * or pulldowns. Careful!
- */
- ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
- if (ret)
- dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
- pdata->pullups, pdata->pulldowns,
- ret);
+ /*
+ * NOTE: boards may waste power if they don't set pullups
+ * and pulldowns correctly ... default for non-ULPI pins is
+ * pulldown, and some other pins may have external pullups
+ * or pulldowns. Careful!
+ */
+ ret = gpio_twl4030_pulls(pdata->pullups, pdata->pulldowns);
+ if (ret)
+ dev_dbg(&pdev->dev, "pullups %.05x %.05x --> %d\n",
+ pdata->pullups, pdata->pulldowns,
+ ret);
- twl_gpiochip.base = pdata->gpio_base;
- twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
- twl_gpiochip.dev = &pdev->dev;
+ twl_gpiochip.base = pdata->gpio_base;
+ twl_gpiochip.ngpio = TWL4030_GPIO_MAX;
+ twl_gpiochip.dev = &pdev->dev;
- ret = gpiochip_add(&twl_gpiochip);
- if (ret < 0) {
- dev_err(&pdev->dev,
- "could not register gpiochip, %d\n",
- ret);
- twl_gpiochip.ngpio = 0;
- gpio_twl4030_remove(pdev);
- } else if (pdata->setup) {
- int status;
+ ret = gpiochip_add(&twl_gpiochip);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "could not register gpiochip, %d\n",
+ ret);
+ twl_gpiochip.ngpio = 0;
+ gpio_twl4030_remove(pdev);
+ } else if (pdata->setup) {
+ int status;
- status = pdata->setup(&pdev->dev,
- pdata->gpio_base, TWL4030_GPIO_MAX);
- if (status)
- dev_dbg(&pdev->dev, "setup --> %d\n", status);
- }
+ status = pdata->setup(&pdev->dev,
+ pdata->gpio_base, TWL4030_GPIO_MAX);
+ if (status)
+ dev_dbg(&pdev->dev, "setup --> %d\n", status);
}
return ret;
@@ -738,7 +412,6 @@ static int __devexit gpio_twl4030_remove
{
struct twl4030_gpio_platform_data *pdata = pdev->dev.platform_data;
int status;
- int irq;
if (pdata->teardown) {
status = pdata->teardown(&pdev->dev,
@@ -753,24 +426,12 @@ static int __devexit gpio_twl4030_remove
if (status < 0)
return status;
- if (is_module() || (twl4030_gpio_irq_end - twl4030_gpio_irq_base) <= 0)
+ if (is_module())
return 0;
- /* uninstall the gpio demultiplexing interrupt handler */
- irq = platform_get_irq(pdev, 0);
- set_irq_handler(irq, NULL);
-
- /* uninstall the irq handler for each of the gpio interrupts */
- for (irq = twl4030_gpio_irq_base; irq < twl4030_gpio_irq_end; irq++)
- set_irq_handler(irq, NULL);
-
- /* stop the gpio helper kernel thread */
- if (gpio_helper_thread) {
- kthread_stop(gpio_helper_thread);
- gpio_helper_thread = NULL;
- }
-
- return 0;
+ /* REVISIT no support yet for deregistering all the IRQs */
+ WARN_ON(1);
+ return -EIO;
}
/* Note: this hardware lives inside an I2C-based multi-function device. */
--
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