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Date: Tue, 23 Jul 2013 19:07:01 +0300
From: Grygorii Strashko <grygorii.strashko@...com>
To: Samuel Ortiz <sameo@...ux.intel.com>,
Lee Jones <lee.jones@...aro.org>
CC: Kevin Hilman <khilman@...aro.org>,
Graeme Gregory <gg@...mlogic.co.uk>,
<linux-omap@...r.kernel.org>,
Ruslan Bilovol <ruslan.bilovol@...com>,
<linux-kernel@...r.kernel.org>,
Naga Venkata Srikanth V <vnv.srikanth@...sung.com>,
Oleg_Kosheliev <oleg.kosheliev@...com>,
Grygorii Strashko <grygorii.strashko@...com>
Subject: [PATCH 1/4] mfd: twl6030-irq: migrate to IRQ threaded handler
From: Naga Venkata Srikanth V <vnv.srikanth@...sung.com>
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.
Signed-off-by: Naga Venkata Srikanth V <vnv.srikanth@...sung.com>
Signed-off-by: Oleg_Kosheliev <oleg.kosheliev@...com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@...com>
---
drivers/mfd/twl6030-irq.c | 146 +++++++++++++++------------------------------
1 file changed, 49 insertions(+), 97 deletions(-)
diff --git a/drivers/mfd/twl6030-irq.c b/drivers/mfd/twl6030-irq.c
index 277a8db..b6030d9 100644
--- a/drivers/mfd/twl6030-irq.c
+++ b/drivers/mfd/twl6030-irq.c
@@ -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;
-
- /* 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;
+ /* 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("%s: I2C error %d reading PIH ISR\n", __func__, ret);
+ return IRQ_HANDLED;
+ }
- sts.bytes[3] = 0; /* Only 24 bits are valid*/
+ 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;
+ /*
+ * 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 +
+ 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("%s: PIH ISR %u, virq%u\n",
+ __func__, 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_warning("twl6030: I2C error in clearing PIH ISR\n");
-
- enable_irq(irq);
- }
-
- return 0;
-}
+ /*
+ * 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: 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 +356,25 @@ 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);
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);
@@ -437,10 +386,13 @@ int twl6030_exit_irq(void)
{
unregister_pm_notifier(&twl6030_irq_pm_notifier_block);
- if (twl6030_irq_base) {
+ if (!twl6030_irq_base) {
pr_err("twl6030: can't yet clean up IRQs?\n");
return -ENOSYS;
}
+
+ free_irq(twl_irq, NULL);
+
return 0;
}
--
1.7.9.5
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