Commit 87343e53 authored by Naga Venkata Srikanth V's avatar Naga Venkata Srikanth V Committed by Samuel Ortiz
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mfd: twl6030-irq: Migrate to IRQ threaded handler 



1) Removed request_irq() and replaced it with request_threaded_irq().

2) Removed generic_handle_irq() and replaced it with
handle_nested_irq().
  Handling of these interrupts is nested, as we are handling an
interrupt (for e.g rtc, mmc1) when we are still servicing TWL irq.

3) Removed I2C read-retry logic for the case when twl_i2c_read() is
failed inside IRQ handler - there is no sense to do that, so just report
an error and return.

4) Each nested IRQ is configured with corresponding parent_irq,
which need to be retriggered in case if nested IRQ is marked
as IRQS_PENDING.

Signed-off-by: default avatarNaga Venkata Srikanth V <vnv.srikanth@samsung.com>
Signed-off-by: default avatarOleg_Kosheliev <oleg.kosheliev@ti.com>
Signed-off-by: default avatarGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: default avatarGraeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: default avatarSamuel Ortiz <sameo@linux.intel.com>
parent cc01b463

drivers/mfd/twl6030-irq.c

+50 −100
Original line number Diff line number Diff line
@@ -90,7 +90,6 @@ static unsigned twl6030_irq_base; 
static int twl_irq;

static bool twl_irq_wake_enabled;



static struct completion irq_event;

static atomic_t twl6030_wakeirqs = ATOMIC_INIT(0);



static int twl6030_irq_pm_notifier(struct notifier_block *notifier,
@@ -131,43 +130,26 @@ static struct notifier_block twl6030_irq_pm_notifier_block = { 
};



/*

 * This thread processes interrupts reported by the Primary Interrupt Handler.

* Threaded irq handler for the twl6030 interrupt.

* We query the interrupt controller in the twl6030 to determine

* which module is generating the interrupt request and call

* handle_nested_irq for that module.

*/

static int twl6030_irq_thread(void *data)

static irqreturn_t twl6030_irq_thread(int irq, void *data)

{

	long irq = (long)data;

	static unsigned i2c_errors;

	static const unsigned max_i2c_errors = 100;

	int ret;



	while (!kthread_should_stop()) {

		int i;

	int i, ret;

	union {

		u8 bytes[4];

		u32 int_sts;

	} sts;



		/* Wait for IRQ, then read PIH irq status (also blocking) */

		wait_for_completion_interruptible(&irq_event);



	/* read INT_STS_A, B and C in one shot using a burst read */

		ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes,

				REG_INT_STS_A, 3);

	ret = twl_i2c_read(TWL_MODULE_PIH, sts.bytes, REG_INT_STS_A, 3);

	if (ret) {

			pr_warning("twl6030: I2C error %d reading PIH ISR\n",

					ret);

			if (++i2c_errors >= max_i2c_errors) {

				printk(KERN_ERR "Maximum I2C error count"

						" exceeded.  Terminating %s.\n",

						__func__);

				break;

			}

			complete(&irq_event);

			continue;

		pr_warn("twl6030_irq: I2C error %d reading PIH ISR\n", ret);

		return IRQ_HANDLED;

	}







	sts.bytes[3] = 0; /* Only 24 bits are valid*/



	/*
@@ -177,15 +159,13 @@ static int twl6030_irq_thread(void *data) 
	if (sts.bytes[2] & 0x10)

		sts.bytes[2] |= 0x08;



		for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++) {

			local_irq_disable();

	for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++)

		if (sts.int_sts & 0x1) {

			int module_irq = twl6030_irq_base +

					twl6030_interrupt_mapping[i];

				generic_handle_irq(module_irq);



			}

		local_irq_enable();

			handle_nested_irq(module_irq);

			pr_debug("twl6030_irq: PIH ISR %u, virq%u\n",

				 i, module_irq);

		}



	/*
@@ -199,27 +179,8 @@ static int twl6030_irq_thread(void *data) 
	 */

	ret = twl_i2c_write_u8(TWL_MODULE_PIH, 0x00, REG_INT_STS_A);

	if (ret)

			pr_warning("twl6030: I2C error in clearing PIH ISR\n");



		enable_irq(irq);

	}

		pr_warn("twl6030_irq: I2C error in clearing PIH ISR\n");



	return 0;

}



/*

 * handle_twl6030_int() is the desc->handle method for the twl6030 interrupt.

 * This is a chained interrupt, so there is no desc->action method for it.

 * Now we need to query the interrupt controller in the twl6030 to determine

 * which module is generating the interrupt request.  However, we can't do i2c

 * transactions in interrupt context, so we must defer that work to a kernel

 * thread.  All we do here is acknowledge and mask the interrupt and wakeup

 * the kernel thread.

 */

static irqreturn_t handle_twl6030_pih(int irq, void *devid)

{

	disable_irq_nosync(irq);

	complete(devid);

	return IRQ_HANDLED;

}
@@ -351,7 +312,6 @@ int twl6030_init_irq(struct device *dev, int irq_num) 
{

	struct			device_node *node = dev->of_node;

	int			nr_irqs, irq_base, irq_end;

	struct task_struct	*task;

	static struct irq_chip  twl6030_irq_chip;

	int			status = 0;

	int			i;
@@ -396,36 +356,26 @@ int twl6030_init_irq(struct device *dev, int irq_num) 
		irq_set_chip_and_handler(i, &twl6030_irq_chip,

					 handle_simple_irq);

		irq_set_chip_data(i, (void *)irq_num);

		irq_set_nested_thread(i, true);

		irq_set_parent(i, irq_num);

		activate_irq(i);

	}



	dev_info(dev, "PIH (irq %d) chaining IRQs %d..%d\n",

	dev_info(dev, "PIH (irq %d) nested IRQs %d..%d\n",

		 irq_num, irq_base, irq_end);



	/* install an irq handler to demultiplex the TWL6030 interrupt */

	init_completion(&irq_event);



	status = request_irq(irq_num, handle_twl6030_pih, 0, "TWL6030-PIH",

			     &irq_event);

	status = request_threaded_irq(irq_num, NULL, twl6030_irq_thread,

				      IRQF_ONESHOT, "TWL6030-PIH", NULL);

	if (status < 0) {

		dev_err(dev, "could not claim irq %d: %d\n", irq_num, status);

		goto fail_irq;

	}



	task = kthread_run(twl6030_irq_thread, (void *)irq_num, "twl6030-irq");

	if (IS_ERR(task)) {

		dev_err(dev, "could not create irq %d thread!\n", irq_num);

		status = PTR_ERR(task);

		goto fail_kthread;

	}



	twl_irq = irq_num;

	register_pm_notifier(&twl6030_irq_pm_notifier_block);

	return irq_base;



fail_kthread:

	free_irq(irq_num, &irq_event);



fail_irq:

	for (i = irq_base; i < irq_end; i++)

		irq_set_chip_and_handler(i, NULL, NULL);
@@ -435,12 +385,12 @@ fail_irq: 


int twl6030_exit_irq(void)

{

	unregister_pm_notifier(&twl6030_irq_pm_notifier_block);



	if (twl6030_irq_base) {

		pr_err("twl6030: can't yet clean up IRQs?\n");

		return -ENOSYS;

	if (twl_irq) {

		unregister_pm_notifier(&twl6030_irq_pm_notifier_block);

		free_irq(twl_irq, NULL);

	}



	return 0;

}

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