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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: Naga Venkata Srikanth V <vnv.srikanth@samsung.com>
Signed-off-by: Oleg_Kosheliev <oleg.kosheliev@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Acked-by: Graeme Gregory <gg@slimlogic.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
This commit is contained in:
Naga Venkata Srikanth V 2013-07-25 16:15:47 +03:00 committed by Samuel Ortiz
parent cc01b4639c
commit 87343e5341
1 changed files with 54 additions and 104 deletions
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158
drivers/mfd/twl6030-irq.c
View File

@ -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,
@ -131,95 +130,57 @@ static struct notifier_block twl6030_irq_pm_notifier_block = {
};
/*
* This thread processes interrupts reported by the Primary Interrupt Handler.
*/
static int twl6030_irq_thread(void *data)
* 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 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;
union {
int i, ret;
union {
u8 bytes[4];
u32 int_sts;
} 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);
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;
}
sts.bytes[3] = 0; /* Only 24 bits are valid*/
/*
* Since VBUS status bit is not reliable for VBUS disconnect
* use CHARGER VBUS detection status bit instead.
*/
if (sts.bytes[2] & 0x10)
sts.bytes[2] |= 0x08;
for (i = 0; sts.int_sts; sts.int_sts >>= 1, i++) {
local_irq_disable();
if (sts.int_sts & 0x1) {
int module_irq = twl6030_irq_base +
twl6030_interrupt_mapping[i];
generic_handle_irq(module_irq);
}
local_irq_enable();
}
/*
* NOTE:
* Simulation confirms that documentation is wrong w.r.t the
* interrupt status clear operation. A single *byte* write to
* any one of STS_A to STS_C register results in all three
* STS registers being reset. Since it does not matter which
* value is written, all three registers are cleared on a
* single byte write, so we just use 0x0 to clear.
*/
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);
/* 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);
if (ret) {
pr_warn("twl6030_irq: I2C error %d reading PIH ISR\n", ret);
return IRQ_HANDLED;
}
return 0;
}
sts.bytes[3] = 0; /* Only 24 bits are valid*/
/*
* Since VBUS status bit is not reliable for VBUS disconnect
* use CHARGER VBUS detection status bit instead.
*/
if (sts.bytes[2] & 0x10)
sts.bytes[2] |= 0x08;
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];
handle_nested_irq(module_irq);
pr_debug("twl6030_irq: PIH ISR %u, virq%u\n",
i, module_irq);
}
/*
* NOTE:
* Simulation confirms that documentation is wrong w.r.t the
* interrupt status clear operation. A single *byte* write to
* any one of STS_A to STS_C register results in all three
* STS registers being reset. Since it does not matter which
* value is written, all three registers are cleared on a
* single byte write, so we just use 0x0 to clear.
*/
ret = twl_i2c_write_u8(TWL_MODULE_PIH, 0x00, REG_INT_STS_A);
if (ret)
pr_warn("twl6030_irq: I2C error in clearing PIH ISR\n");
/*
* 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",
irq_num, irq_base, irq_end);
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;
}