[PATCH 2/2] media: pwm-ir-tx: add regulator support

[Roman Vivchar via B4 Relay]

From: Roman Vivchar <rva333@xxxxxxxxxxxxxx>

On some boards, the IR LED shares a power rail with other components.
If that rail is turned off, IR transmission can't function properly.

Add optional regulator support to ensure the power supply is enabled when
needed.

Signed-off-by: Roman Vivchar <rva333@xxxxxxxxxxxxxx>
---
 drivers/media/rc/pwm-ir-tx.c | 37 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 36 insertions(+), 1 deletion(-)

diff --git a/drivers/media/rc/pwm-ir-tx.c b/drivers/media/rc/pwm-ir-tx.c
index 047472dc9244..f9c95d034493 100644
--- a/drivers/media/rc/pwm-ir-tx.c
+++ b/drivers/media/rc/pwm-ir-tx.c
@@ -10,6 +10,7 @@
 #include <linux/slab.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 #include <linux/hrtimer.h>
 #include <linux/completion.h>
 #include <media/rc-core.h>
@@ -19,6 +20,7 @@
 
 struct pwm_ir {
 	struct pwm_device *pwm;
+	struct regulator *reg;
 	struct hrtimer timer;
 	struct completion tx_done;
 	struct pwm_state *state;
@@ -63,10 +65,16 @@ static int pwm_ir_tx_sleep(struct rc_dev *dev, unsigned int *txbuf,
 	struct pwm_ir *pwm_ir = dev->priv;
 	struct pwm_device *pwm = pwm_ir->pwm;
 	struct pwm_state state;
-	int i;
+	int i, ret;
 	ktime_t edge;
 	long delta;
 
+	if (pwm_ir->reg) {
+		ret = regulator_enable(pwm_ir->reg);
+		if (ret)
+			return ret;
+	}
+
 	pwm_init_state(pwm, &state);
 
 	state.period = DIV_ROUND_CLOSEST(NSEC_PER_SEC, pwm_ir->carrier);
@@ -87,6 +95,12 @@ static int pwm_ir_tx_sleep(struct rc_dev *dev, unsigned int *txbuf,
 	state.enabled = false;
 	pwm_apply_might_sleep(pwm, &state);
 
+	if (pwm_ir->reg) {
+		ret = regulator_disable(pwm_ir->reg);
+		if (ret)
+			return ret;
+	}
+
 	return count;
 }
 
@@ -96,6 +110,7 @@ static int pwm_ir_tx_atomic(struct rc_dev *dev, unsigned int *txbuf,
 	struct pwm_ir *pwm_ir = dev->priv;
 	struct pwm_device *pwm = pwm_ir->pwm;
 	struct pwm_state state;
+	int ret;
 
 	pwm_init_state(pwm, &state);
 
@@ -107,10 +122,22 @@ static int pwm_ir_tx_atomic(struct rc_dev *dev, unsigned int *txbuf,
 	pwm_ir->txbuf_index = 0;
 	pwm_ir->state = &state;
 
+	if (pwm_ir->reg) {
+		ret = regulator_enable(pwm_ir->reg);
+		if (ret)
+			return ret;
+	}
+
 	hrtimer_start(&pwm_ir->timer, 0, HRTIMER_MODE_REL);
 
 	wait_for_completion(&pwm_ir->tx_done);
 
+	if (pwm_ir->reg) {
+		ret = regulator_disable(pwm_ir->reg);
+		if (ret)
+			return ret;
+	}
+
 	return count;
 }
 
@@ -157,6 +184,14 @@ static int pwm_ir_probe(struct platform_device *pdev)
 	if (IS_ERR(pwm_ir->pwm))
 		return PTR_ERR(pwm_ir->pwm);
 
+	pwm_ir->reg = devm_regulator_get_optional(&pdev->dev, "power");
+	if (IS_ERR(pwm_ir->reg)) {
+		if (PTR_ERR(pwm_ir->reg) != -ENODEV)
+			return PTR_ERR(pwm_ir->reg);
+
+		pwm_ir->reg = NULL;
+	}
+
 	pwm_ir->carrier = 38000;
 	pwm_ir->duty_cycle = 50;
 

-- 
2.56.0