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From: Lee Jones <lee.jones@linaro.org>
To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Cc: kernel@stlinux.com, maxime.coquelin@st.com,
	patrice.chotard@st.com, thierry.reding@gmail.com,
	robh+dt@kernel.org, linux-pwm@vger.kernel.org,
	devicetree@vger.kernel.org, Lee Jones <lee.jones@linaro.org>
Subject: [PATCH v3 16/20] pwm: sti: Add support for PWM Capture IRQs
Date: Wed,  8 Jun 2016 10:21:31 +0100	[thread overview]
Message-ID: <20160608092135.21184-17-lee.jones@linaro.org> (raw)
In-Reply-To: <20160608092135.21184-1-lee.jones@linaro.org>

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.jones@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);
+			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.
-- 
2.8.3

  parent reply	other threads:[~2016-06-08  9:23 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-08  9:21 [PATCH v3 00/20] pwm: Add support for PWM Capture Lee Jones
2016-06-08  9:21 ` [PATCH v3 01/20] ARM: dts: STi: Rename properites in line with PWM naming conventions Lee Jones
2016-06-08  9:21 ` [PATCH v3 02/20] ARM: dts: STiH407: Supply PWM Capture IRQ Lee Jones
2016-06-08  9:21 ` [PATCH v3 03/20] ARM: dts: STiH407: Declare PWM Capture data lines via Pinctrl Lee Jones
2016-06-08  9:21 ` [PATCH v3 04/20] ARM: dts: STiH416: Supply PWM Capture IRQs Lee Jones
2016-06-08  9:21 ` [PATCH v3 05/20] ARM: dts: STiH416: Declare PWM Capture data lines via Pinctrl Lee Jones
2016-06-08  9:21 ` [PATCH v3 06/20] ARM: dts: STiH416: Define PWM Capture clock Lee Jones
2016-06-08  9:21 ` [PATCH v3 07/20] ARM: dts: STiH416: Define the number of PWM Capture channels Lee Jones
2016-06-08  9:21 ` [PATCH v3 08/20] pwm: Add PWM Capture support Lee Jones
2016-06-10 13:53   ` Thierry Reding
2016-06-10 14:38     ` Lee Jones
2016-06-10 16:39       ` Thierry Reding
2016-06-20 11:14         ` Lee Jones
2016-06-08  9:21 ` [PATCH v3 09/20] pwm: sti: Rename channel => device Lee Jones
2016-06-08  9:21 ` [PATCH v3 10/20] pwm: sysfs: Add PWM Capture support Lee Jones
2016-06-10 14:04   ` Thierry Reding
2016-06-10 14:36     ` Lee Jones
2016-06-08  9:21 ` [PATCH v3 11/20] pwm: sti: Reorganise register names in preparation for new functionality Lee Jones
2016-06-08  9:21 ` [PATCH v3 12/20] pwm: sti: Only request clock rate when you need to Lee Jones
2016-06-08  9:21 ` [PATCH v3 13/20] pwm: sti: Supply PWM Capture register addresses and bit locations Lee Jones
2016-06-08  9:21 ` [PATCH v3 14/20] pwm: sti: Supply PWM Capture clock handling Lee Jones
2016-06-08  9:21 ` [PATCH v3 15/20] pwm: sti: Initialise PWM Capture device data Lee Jones
2016-06-08  9:21 ` Lee Jones [this message]
2016-06-08  9:21 ` [PATCH v3 17/20] pwm: sti: Add PWM Capture call-back Lee Jones
2016-06-08  9:21 ` [PATCH v3 18/20] pwm: sti: It's now valid for number of PWM channels to be zero Lee Jones
2016-06-08  9:21 ` [PATCH v3 19/20] pwm: sti: Take the opportunity to conduct a little house keeping Lee Jones
2016-06-08  9:21 ` [PATCH v3 20/20] dt-bindings: pwm: sti: Update DT bindings with recent changes Lee Jones
2016-06-08 20:51   ` Rob Herring
2016-06-09 11:41     ` Lee Jones
2016-06-10 13:18       ` Thierry Reding
2016-06-10 14:06         ` Lee Jones
2016-06-10 14:53           ` Thierry Reding
2016-06-10 15:19             ` Lee Jones
2016-07-13  9:02             ` Lee Jones
2016-06-10 13:10     ` Thierry Reding

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