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pwm: sti: Add support for PWM capture interrupts

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Here we're requesting the PWM capture IRQ and supplying the handler that
will be called in the event of an interrupt to handle it.

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Lee Jones 2016-08-16 10:35:04 +01:00 committed by Thierry Reding
parent 3f0925b5a8
commit 25eb538096
1 changed files with 91 additions and 1 deletions
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92
drivers/pwm/pwm-sti.c
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@ -91,7 +91,9 @@ struct sti_pwm_chip {
struct regmap_field *prescale_low;
struct regmap_field *prescale_high;
struct regmap_field *pwm_out_en;
struct regmap_field *pwm_cpt_en;
struct regmap_field *pwm_cpt_int_en;
struct regmap_field *pwm_cpt_int_stat;
struct pwm_chip chip;
struct pwm_device *cur;
unsigned long configured;
@ -311,6 +313,76 @@ static const struct pwm_ops sti_pwm_ops = {
.owner = THIS_MODULE,
};
static irqreturn_t sti_pwm_interrupt(int irq, void *data)
{
struct sti_pwm_chip *pc = data;
struct device *dev = pc->dev;
struct sti_cpt_ddata *ddata;
int devicenum;
unsigned int cpt_int_stat;
unsigned int reg;
int ret = IRQ_NONE;
ret = regmap_field_read(pc->pwm_cpt_int_stat, &cpt_int_stat);
if (ret)
return ret;
while (cpt_int_stat) {
devicenum = ffs(cpt_int_stat) - 1;
ddata = pwm_get_chip_data(&pc->chip.pwms[devicenum]);
/*
* Capture input:
* _______ _______
* | | | |
* __| |_________________| |________
* ^0 ^1 ^2
*
* Capture start by the first available rising edge
* When a capture event occurs, capture value (CPT_VALx)
* is stored, index incremented, capture edge changed.
*
* After the capture, if the index > 1, we have collected
* the necessary data so we signal the thread waiting for it
* and disable the capture by setting capture edge to none
*
*/
regmap_read(pc->regmap,
PWM_CPT_VAL(devicenum),
&ddata->snapshot[ddata->index]);
switch (ddata->index) {
case 0:
case 1:
regmap_read(pc->regmap, PWM_CPT_EDGE(devicenum), &reg);
reg ^= PWM_CPT_EDGE_MASK;
regmap_write(pc->regmap, PWM_CPT_EDGE(devicenum), reg);
ddata->index++;
break;
case 2:
regmap_write(pc->regmap,
PWM_CPT_EDGE(devicenum),
CPT_EDGE_DISABLED);
wake_up(&ddata->wait);
break;
default:
dev_err(dev, "Internal error\n");
}
cpt_int_stat &= ~BIT_MASK(devicenum);
ret = IRQ_HANDLED;
}
/* Just ACK everything */
regmap_write(pc->regmap, PWM_INT_ACK, PWM_INT_ACK_MASK);
return ret;
}
static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
{
struct device *dev = pc->dev;
@ -351,6 +423,11 @@ static int sti_pwm_probe_dt(struct sti_pwm_chip *pc)
if (IS_ERR(pc->pwm_cpt_int_en))
return PTR_ERR(pc->pwm_cpt_int_en);
pc->pwm_cpt_int_stat = devm_regmap_field_alloc(dev, pc->regmap,
reg_fields[PWM_CPT_INT_STAT]);
if (PTR_ERR_OR_ZERO(pc->pwm_cpt_int_stat))
return PTR_ERR(pc->pwm_cpt_int_stat);
return 0;
}
@ -367,7 +444,7 @@ static int sti_pwm_probe(struct platform_device *pdev)
struct sti_pwm_chip *pc;
struct resource *res;
unsigned int i;
int ret;
int irq, ret;
pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
@ -388,6 +465,19 @@ static int sti_pwm_probe(struct platform_device *pdev)
if (IS_ERR(pc->regmap))
return PTR_ERR(pc->regmap);
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "Failed to obtain IRQ\n");
return irq;
}
ret = devm_request_irq(&pdev->dev, irq, sti_pwm_interrupt, 0,
pdev->name, pc);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to request IRQ\n");
return ret;
}
/*
* Setup PWM data with default values: some values could be replaced
* with specific ones provided from Device Tree.