linux-kernel - [PATCH 1/3] pwm: cros-ec: Don't care about consumers in .get

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Message-ID: <20240607084416.897777-6-u.kleine-koenig@baylibre.com>
Date: Fri,  7 Jun 2024 10:44:15 +0200
From: "Uwe Kleine-König" <ukleinek@...libre.com>
To: Benson Leung <bleung@...omium.org>
Cc: Guenter Roeck <groeck@...omium.org>,
	linux-pwm@...r.kernel.org,
	chrome-platform@...ts.linux.dev,
	linux-kernel@...r.kernel.org
Subject: [PATCH 1/3] pwm: cros-ec: Don't care about consumers in .get_state()

The get_state() callback is never called (in a visible way) after there
is a consumer for a pwm device. The core handles loosing the information
about duty_cycle just fine.

Simplify the driver accordingly.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...libre.com>
---
 drivers/pwm/pwm-cros-ec.c | 33 +--------------------------------
 1 file changed, 1 insertion(+), 32 deletions(-)

diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 606ccfdaf4cc..ba4ee0b507b7 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -25,15 +25,6 @@
 struct cros_ec_pwm_device {
 	struct cros_ec_device *ec;
 	bool use_pwm_type;
-	struct cros_ec_pwm *channel;
-};
-
-/**
- * struct cros_ec_pwm - per-PWM driver data
- * @duty_cycle: cached duty cycle
- */
-struct cros_ec_pwm {
-	u16 duty_cycle;
 };
 
 static inline struct cros_ec_pwm_device *pwm_to_cros_ec_pwm(struct pwm_chip *chip)
@@ -135,7 +126,6 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 			     const struct pwm_state *state)
 {
 	struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip);
-	struct cros_ec_pwm *channel = &ec_pwm->channel[pwm->hwpwm];
 	u16 duty_cycle;
 	int ret;
 
@@ -156,8 +146,6 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (ret < 0)
 		return ret;
 
-	channel->duty_cycle = state->duty_cycle;
-
 	return 0;
 }
 
@@ -165,7 +153,6 @@ static int cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 				 struct pwm_state *state)
 {
 	struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip);
-	struct cros_ec_pwm *channel = &ec_pwm->channel[pwm->hwpwm];
 	int ret;
 
 	ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, pwm->hwpwm);
@@ -175,23 +162,10 @@ static int cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	}
 
 	state->enabled = (ret > 0);
+	state->duty_cycle = ret;
 	state->period = EC_PWM_MAX_DUTY;
 	state->polarity = PWM_POLARITY_NORMAL;
 
-	/*
-	 * Note that "disabled" and "duty cycle == 0" are treated the same. If
-	 * the cached duty cycle is not zero, used the cached duty cycle. This
-	 * ensures that the configured duty cycle is kept across a disable and
-	 * enable operation and avoids potentially confusing consumers.
-	 *
-	 * For the case of the initial hardware readout, channel->duty_cycle
-	 * will be 0 and the actual duty cycle read from the EC is used.
-	 */
-	if (ret == 0 && channel->duty_cycle > 0)
-		state->duty_cycle = channel->duty_cycle;
-	else
-		state->duty_cycle = ret;
-
 	return 0;
 }
 
@@ -291,11 +265,6 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
 	chip->ops = &cros_ec_pwm_ops;
 	chip->of_xlate = cros_ec_pwm_xlate;
 
-	ec_pwm->channel = devm_kcalloc(dev, chip->npwm, sizeof(*ec_pwm->channel),
-					GFP_KERNEL);
-	if (!ec_pwm->channel)
-		return -ENOMEM;
-
 	dev_dbg(dev, "Probed %u PWMs\n", chip->npwm);
 
 	ret = devm_pwmchip_add(dev, chip);
-- 
2.43.0