Re: [PATCH v3 1/5] drivers: pinctrl: qcom: add wakeup capability to GPIO
From: Lina Iyer
Date: Tue Oct 09 2018 - 13:07:07 EST
On Tue, Oct 02 2018 at 11:06 -0600, Lina Iyer wrote:
Marc,
I am exploring an option where we don't do this enable/disable every
suspend/resume and in that process, I was able to just use the PDC
interrupt instead of the TLMM for triggering the GPIO. The PDC interrupt
(which takes over for the GPIO) has an handler like this -
On Tue, Sep 04 2018 at 15:18 -0600, Lina Iyer wrote:
QCOM SoC's that have Power Domain Controller (PDC) chip in the always-on
domain can wakeup the SoC, when interrupts and GPIOs are routed to its
interrupt controller. Only select GPIOs that are deemed wakeup capable
are routed to specific PDC pins. During low power state, the pinmux
interrupt controller may be non-functional but the PDC would be. The PDC
can detect the wakeup GPIO is triggered and bring the TLMM to an
operational state.
Interrupts that are level triggered will be detected at the TLMM when
the controller becomes operational. Edge interrupts however need to be
replayed again.
Request the corresponding PDC IRQ, when the GPIO is requested as an IRQ,
but keep it disabled. During suspend, we can enable the PDC IRQ instead
of the GPIO IRQ, which may or not be detected.
Signed-off-by: Lina Iyer <ilina@xxxxxxxxxxxxxx>
---
Changes in v3:
- free action->name
Changes in v2:
- Remove IRQF_NO_SUSPEND and IRQF_ONE_SHOT from PDC IRQ
Changes in v1:
- Trigger GPIO in h/w from PDC IRQ handler
- Avoid big tables for GPIO-PDC map, pick from DT instead
- Use handler_data
---
drivers/pinctrl/qcom/pinctrl-msm.c | 98 ++++++++++++++++++++++++++++++
1 file changed, 98 insertions(+)
diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
index 0e22f52b2a19..6527a0a9edd1 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -687,11 +687,15 @@ static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int type)
const struct msm_pingroup *g;
unsigned long flags;
u32 val;
+ struct irq_data *pdc_irqd = irq_get_handler_data(d->irq);
g = &pctrl->soc->groups[d->hwirq];
raw_spin_lock_irqsave(&pctrl->lock, flags);
+ if (pdc_irqd)
+ irq_set_irq_type(pdc_irqd->irq, type);
+
I skip over the TLMM configuration for the GPIO interrupt and just set
the IRQ handler for the GPIO interrupt here..
/*
* For hw without possibility of detecting both edges
*/
@@ -779,9 +783,13 @@ static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
unsigned long flags;
+ struct irq_data *pdc_irqd = irq_get_handler_data(d->irq);
raw_spin_lock_irqsave(&pctrl->lock, flags);
+ if (pdc_irqd)
+ irq_set_irq_wake(pdc_irqd->irq, on);
+
irq_set_irq_wake(pctrl->irq, on);
raw_spin_unlock_irqrestore(&pctrl->lock, flags);
@@ -863,6 +871,94 @@ static bool msm_gpio_needs_valid_mask(struct msm_pinctrl *pctrl)
return device_property_read_u16_array(pctrl->dev, "gpios", NULL, 0) > 0;
}
+static irqreturn_t wake_irq_gpio_handler(int irq, void *data)
+{
+ struct irq_data *irqd = data;
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+ struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
+ const struct msm_pingroup *g;
+ unsigned long flags;
+ u32 val;
+
+ if (!irqd_is_level_type(irqd)) {
+ g = &pctrl->soc->groups[irqd->hwirq];
+ raw_spin_lock_irqsave(&pctrl->lock, flags);
+ val = BIT(g->intr_status_bit);
+ writel(val, pctrl->regs + g->intr_status_reg);
+ raw_spin_unlock_irqrestore(&pctrl->lock, flags);
+ }
+
+ return IRQ_HANDLED;
+}
+
Then ...
static irqreturn_t wake_irq_gpio_handler(int irq, void *data)
{
struct irq_data *irqd = data;
struct irq_desc *desc = irq_to_desc(irqd->irq);
desc->handle_irq(desc);
return IRQ_HANDLED;
}
I am following check_irq_resend() but I need to call the handler for
both level and edge interrupts. Firstly, is it okay to call the
handler_irq() directly?
My other question is check_irq_resend() indicates that it should be
called with desc->lock held. Since we are invoking the handler directly
and not modifying any core state of the irq_desc, is it safe here? (Also
the locking API are not exposed, I am sure there must be a reason for it).
Thoughts?
Would it help if I submit a RFC patch based on this idea?
Thanks,
Lina
+static int msm_gpio_pdc_pin_request(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+ struct msm_pinctrl *pctrl = gpiochip_get_data(gc);
+ struct platform_device *pdev = to_platform_device(pctrl->dev);
+ const char *pin_name;
+ int irq;
+ int ret;
+
+ pin_name = kasprintf(GFP_KERNEL, "gpio%lu", d->hwirq);
+ if (!pin_name)
+ return -ENOMEM;
+
+ irq = platform_get_irq_byname(pdev, pin_name);
+ if (irq < 0) {
+ kfree(pin_name);
+ return 0;
+ }
+
+ ret = request_irq(irq, wake_irq_gpio_handler, irqd_get_trigger_type(d),
+ pin_name, d);
+ if (ret) {
+ pr_warn("GPIO-%lu could not be set up as wakeup", d->hwirq);
+ kfree(pin_name);
+ return ret;
+ }
+
+ irq_set_handler_data(d->irq, irq_get_irq_data(irq));
+ disable_irq(irq);
+
+ return 0;
+}
+
+static int msm_gpio_pdc_pin_release(struct irq_data *d)
+{
+ struct irq_data *pdc_irqd = irq_get_handler_data(d->irq);
+ const void *name;
+
+ if (pdc_irqd) {
+ irq_set_handler_data(d->irq, NULL);
+ name = free_irq(pdc_irqd->irq, d);
+ kfree(name);
+ }
+
+ return 0;
+}
+
+static int msm_gpio_irq_reqres(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+ if (gpiochip_lock_as_irq(gc, irqd_to_hwirq(d))) {
+ dev_err(gc->parent, "unable to lock HW IRQ %lu for IRQ\n",
+ irqd_to_hwirq(d));
+ return -EINVAL;
+ }
+
+ return msm_gpio_pdc_pin_request(d);
+}
+
+static void msm_gpio_irq_relres(struct irq_data *d)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+ msm_gpio_pdc_pin_release(d);
+ gpiochip_unlock_as_irq(gc, irqd_to_hwirq(d));
+}
+
static int msm_gpio_init(struct msm_pinctrl *pctrl)
{
struct gpio_chip *chip;
@@ -887,6 +983,8 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl)
pctrl->irq_chip.irq_ack = msm_gpio_irq_ack;
pctrl->irq_chip.irq_set_type = msm_gpio_irq_set_type;
pctrl->irq_chip.irq_set_wake = msm_gpio_irq_set_wake;
+ pctrl->irq_chip.irq_request_resources = msm_gpio_irq_reqres;
+ pctrl->irq_chip.irq_release_resources = msm_gpio_irq_relres;
ret = gpiochip_add_data(&pctrl->chip, pctrl);
if (ret) {
--
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