Hi Lee,
On Fri, 22 Apr 2016, Lee Jones wrote:
> Here we're requesting the PWM Capture IRQ and supplying the
> handler which will be called in the event of an IRQ fire to
> handle it.
>
> Signed-off-by: Lee Jones <lee.jo...@linaro.org>
> ---
> drivers/pwm/pwm-sti.c | 92
> ++++++++++++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 91 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c
> index 9d597bb..2230afb 100644
> --- a/drivers/pwm/pwm-sti.c
> +++ b/drivers/pwm/pwm-sti.c
> @@ -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 ^= 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 devnum;
> - 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.
pwm-st.txt dt binding document and pwm example needs updating to document this
irq.
regards,
Peter
