From 6f57937980142715e927697a6ffd2050f38ed6f6 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 22 Mar 2023 22:45:40 +0100 Subject: pwm: hibvt: Explicitly set .polarity in .get_state() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The driver only both polarities. Complete the implementation of .get_state() by setting .polarity according to the configured hardware state. Fixes: d09f00810850 ("pwm: Add PWM driver for HiSilicon BVT SOCs") Link: https://lore.kernel.org/r/20230228135508.1798428-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding --- drivers/pwm/pwm-hibvt.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/pwm/pwm-hibvt.c b/drivers/pwm/pwm-hibvt.c index 12c05c155cab..1b9274c5ad87 100644 --- a/drivers/pwm/pwm-hibvt.c +++ b/drivers/pwm/pwm-hibvt.c @@ -146,6 +146,7 @@ static int hibvt_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, value = readl(base + PWM_CTRL_ADDR(pwm->hwpwm)); state->enabled = (PWM_ENABLE_MASK & value); + state->polarity = (PWM_POLARITY_MASK & value) ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL; return 0; } -- cgit v1.2.3 From 30006b77c7e130e01d1ab2148cc8abf73dfcc4bf Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 22 Mar 2023 22:45:41 +0100 Subject: pwm: cros-ec: Explicitly set .polarity in .get_state() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The driver only supports normal polarity. Complete the implementation of .get_state() by setting .polarity accordingly. Reviewed-by: Guenter Roeck Fixes: 1f0d3bb02785 ("pwm: Add ChromeOS EC PWM driver") Link: https://lore.kernel.org/r/20230228135508.1798428-3-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding --- drivers/pwm/pwm-cros-ec.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c index 86df6702cb83..ad18b0ebe3f1 100644 --- a/drivers/pwm/pwm-cros-ec.c +++ b/drivers/pwm/pwm-cros-ec.c @@ -198,6 +198,7 @@ static int cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, state->enabled = (ret > 0); state->period = EC_PWM_MAX_DUTY; + state->polarity = PWM_POLARITY_NORMAL; /* * Note that "disabled" and "duty cycle == 0" are treated the same. If -- cgit v1.2.3 From b20b097128d9145fadcea1cbb45c4d186cb57466 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 22 Mar 2023 22:45:42 +0100 Subject: pwm: iqs620a: Explicitly set .polarity in .get_state() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The driver only supports normal polarity. Complete the implementation of .get_state() by setting .polarity accordingly. Fixes: 6f0841a8197b ("pwm: Add support for Azoteq IQS620A PWM generator") Reviewed-by: Jeff LaBundy Link: https://lore.kernel.org/r/20230228135508.1798428-4-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding --- drivers/pwm/pwm-iqs620a.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/pwm/pwm-iqs620a.c b/drivers/pwm/pwm-iqs620a.c index 8362b4870c66..47b3141135f3 100644 --- a/drivers/pwm/pwm-iqs620a.c +++ b/drivers/pwm/pwm-iqs620a.c @@ -126,6 +126,7 @@ static int iqs620_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, mutex_unlock(&iqs620_pwm->lock); state->period = IQS620_PWM_PERIOD_NS; + state->polarity = PWM_POLARITY_NORMAL; return 0; } -- cgit v1.2.3 From 2be4dcf6627e1bcbbef8e6ba1811f5127d39202c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 22 Mar 2023 22:45:43 +0100 Subject: pwm: sprd: Explicitly set .polarity in .get_state() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The driver only supports normal polarity. Complete the implementation of .get_state() by setting .polarity accordingly. Fixes: 8aae4b02e8a6 ("pwm: sprd: Add Spreadtrum PWM support") Link: https://lore.kernel.org/r/20230228135508.1798428-5-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding --- drivers/pwm/pwm-sprd.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers') diff --git a/drivers/pwm/pwm-sprd.c b/drivers/pwm/pwm-sprd.c index d866ce345f97..bde579a338c2 100644 --- a/drivers/pwm/pwm-sprd.c +++ b/drivers/pwm/pwm-sprd.c @@ -109,6 +109,7 @@ static int sprd_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, duty = val & SPRD_PWM_DUTY_MSK; tmp = (prescale + 1) * NSEC_PER_SEC * duty; state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, chn->clk_rate); + state->polarity = PWM_POLARITY_NORMAL; /* Disable PWM clocks if the PWM channel is not in enable state. */ if (!state->enabled) -- cgit v1.2.3 From 8caa81eb950cb2e9d2d6959b37d853162d197f57 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 22 Mar 2023 22:45:44 +0100 Subject: pwm: meson: Explicitly set .polarity in .get_state() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The driver only supports normal polarity. Complete the implementation of .get_state() by setting .polarity accordingly. This fixes a regression that was possible since commit c73a3107624d ("pwm: Handle .get_state() failures") which stopped to zero-initialize the state passed to the .get_state() callback. This was reported at https://forum.odroid.com/viewtopic.php?f=177&t=46360 . While this was an unintended side effect, the real issue is the driver's callback not setting the polarity. There is a complicating fact, that the .apply() callback fakes support for inversed polarity. This is not (and cannot) be matched by .get_state(). As fixing this isn't easy, only point it out in a comment to prevent authors of other drivers from copying that approach. Fixes: c375bcbaabdb ("pwm: meson: Read the full hardware state in meson_pwm_get_state()") Reported-by: Munehisa Kamata Acked-by: Martin Blumenstingl Link: https://lore.kernel.org/r/20230310191405.2606296-1-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding --- drivers/pwm/pwm-meson.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers') diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index 16d79ca5d8f5..5cd7b90872c6 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -162,6 +162,12 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm, duty = state->duty_cycle; period = state->period; + /* + * Note this is wrong. The result is an output wave that isn't really + * inverted and so is wrongly identified by .get_state as normal. + * Fixing this needs some care however as some machines might rely on + * this. + */ if (state->polarity == PWM_POLARITY_INVERSED) duty = period - duty; @@ -358,6 +364,8 @@ static int meson_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, state->duty_cycle = 0; } + state->polarity = PWM_POLARITY_NORMAL; + return 0; } -- cgit v1.2.3 From 1271a7b98e7989ba6bb978e14403fc84efe16e13 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 22 Mar 2023 22:45:45 +0100 Subject: pwm: Zero-initialize the pwm_state passed to driver's .get_state() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This is just to ensure that .usage_power is properly initialized and doesn't contain random stack data. The other members of struct pwm_state should get a value assigned in a successful call to .get_state(). So in the absence of bugs in driver implementations, this is only a safe-guard and no fix. Reported-by: Munehisa Kamata Link: https://lore.kernel.org/r/20230310214004.2619480-1-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König Signed-off-by: Thierry Reding --- drivers/pwm/core.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index e01147f66e15..474725714a05 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -115,7 +115,14 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) } if (pwm->chip->ops->get_state) { - struct pwm_state state; + /* + * Zero-initialize state because most drivers are unaware of + * .usage_power. The other members of state are supposed to be + * set by lowlevel drivers. We still initialize the whole + * structure for simplicity even though this might paper over + * faulty implementations of .get_state(). + */ + struct pwm_state state = { 0, }; err = pwm->chip->ops->get_state(pwm->chip, pwm, &state); trace_pwm_get(pwm, &state, err); @@ -448,7 +455,7 @@ static void pwm_apply_state_debug(struct pwm_device *pwm, { struct pwm_state *last = &pwm->last; struct pwm_chip *chip = pwm->chip; - struct pwm_state s1, s2; + struct pwm_state s1 = { 0 }, s2 = { 0 }; int err; if (!IS_ENABLED(CONFIG_PWM_DEBUG)) @@ -530,6 +537,7 @@ static void pwm_apply_state_debug(struct pwm_device *pwm, return; } + *last = (struct pwm_state){ 0 }; err = chip->ops->get_state(chip, pwm, last); trace_pwm_get(pwm, last, err); if (err) -- cgit v1.2.3