linux-stable.git/drivers/pwm, branch v6.2.7 Linux kernel stable tree pwm: stm32-lp: fix the check on arr and cmp registers update 2023-03-11T12:50:22+00:00 Fabrice Gasnier fabrice.gasnier@foss.st.com 2022-11-23T13:36:52+00:00 8266383ce2fc762fe216e93ebd0d00c09865f4a6 [ Upstream commit 3066bc2d58be31275afb51a589668f265e419c37 ] The ARR (auto reload register) and CMP (compare) registers are successively written. The status bits to check the update of these registers are polled together with regmap_read_poll_timeout(). The condition to end the loop may become true, even if one of the register isn't correctly updated. So ensure both status bits are set before clearing them. Fixes: e70a540b4e02 ("pwm: Add STM32 LPTimer PWM driver") Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3066bc2d58be31275afb51a589668f265e419c37 ]

The ARR (auto reload register) and CMP (compare) registers are
successively written. The status bits to check the update of these
registers are polled together with regmap_read_poll_timeout().
The condition to end the loop may become true, even if one of the
register isn't correctly updated.
So ensure both status bits are set before clearing them.

Fixes: e70a540b4e02 ("pwm: Add STM32 LPTimer PWM driver")
Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
pwm: sifive: Always let the first pwm_apply_state succeed 2023-03-11T12:50:22+00:00 Emil Renner Berthing emil.renner.berthing@canonical.com 2022-11-09T11:37:24+00:00 832aaf64140419c56a5bcf3b05ff0e56b0bd1fcb [ Upstream commit 334c7b13d38321e47d1a51dba0bef9f4c403ec75 ] Commit 2cfe9bbec56ea579135cdd92409fff371841904f added support for the RGB and green PWM controlled LEDs on the HiFive Unmatched board managed by the leds-pwm-multicolor and leds-pwm drivers respectively. All three colours of the RGB LED and the green LED run from different lines of the same PWM, but with the same period so this works fine when the LED drivers are loaded one after the other. Unfortunately it does expose a race in the PWM driver when both LED drivers are loaded at roughly the same time. Here is an example: | Thread A | Thread B | | led_pwm_mc_probe | led_pwm_probe | | devm_fwnode_pwm_get | | | pwm_sifive_request | | | ddata->user_count++ | | | | devm_fwnode_pwm_get | | | pwm_sifive_request | | | ddata->user_count++ | | ... | ... | | pwm_state_apply | pwm_state_apply | | pwm_sifive_apply | pwm_sifive_apply | Now both calls to pwm_sifive_apply will see that ddata->approx_period, initially 0, is different from the requested period and the clock needs to be updated. But since ddata->user_count >= 2 both calls will fail with -EBUSY, which will then cause both LED drivers to fail to probe. Fix it by letting the first call to pwm_sifive_apply update the clock even when ddata->user_count != 1. Fixes: 9e37a53eb051 ("pwm: sifive: Add a driver for SiFive SoC PWM") Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 334c7b13d38321e47d1a51dba0bef9f4c403ec75 ]

Commit 2cfe9bbec56ea579135cdd92409fff371841904f added support for the
RGB and green PWM controlled LEDs on the HiFive Unmatched board
managed by the leds-pwm-multicolor and leds-pwm drivers respectively.
All three colours of the RGB LED and the green LED run from different
lines of the same PWM, but with the same period so this works fine when
the LED drivers are loaded one after the other.

Unfortunately it does expose a race in the PWM driver when both LED
drivers are loaded at roughly the same time. Here is an example:

  |          Thread A           |          Thread B           |
  |  led_pwm_mc_probe           |  led_pwm_probe              |
  |    devm_fwnode_pwm_get      |                             |
  |      pwm_sifive_request     |                             |
  |        ddata->user_count++  |                             |
  |                             |    devm_fwnode_pwm_get      |
  |                             |      pwm_sifive_request     |
  |                             |        ddata->user_count++  |
  |         ...                 |          ...                |
  |    pwm_state_apply          |    pwm_state_apply          |
  |      pwm_sifive_apply       |      pwm_sifive_apply       |

Now both calls to pwm_sifive_apply will see that ddata->approx_period,
initially 0, is different from the requested period and the clock needs
to be updated. But since ddata->user_count >= 2 both calls will fail
with -EBUSY, which will then cause both LED drivers to fail to probe.

Fix it by letting the first call to pwm_sifive_apply update the clock
even when ddata->user_count != 1.

Fixes: 9e37a53eb051 ("pwm: sifive: Add a driver for SiFive SoC PWM")
Signed-off-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Merge tag 'pwm/for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm 2022-12-21T17:41:28+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-12-21T17:41:28+00:00 7a693ea78e3c48605a2d849fd241ff15561f10d5 Pull pwm updates from Thierry Reding: "Various changes across the board, mostly improvements and cleanups" * tag 'pwm/for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (42 commits) pwm: pca9685: Convert to i2c's .probe_new() pwm: sun4i: Propagate errors in .get_state() to the caller pwm: Handle .get_state() failures pwm: sprd: Propagate errors in .get_state() to the caller pwm: rockchip: Propagate errors in .get_state() to the caller pwm: mtk-disp: Propagate errors in .get_state() to the caller pwm: imx27: Propagate errors in .get_state() to the caller pwm: cros-ec: Propagate errors in .get_state() to the caller pwm: crc: Propagate errors in .get_state() to the caller leds: qcom-lpg: Propagate errors in .get_state() to the caller drm/bridge: ti-sn65dsi86: Propagate errors in .get_state() to the caller pwm/tracing: Also record trace events for failed API calls pwm: Make .get_state() callback return an error code pwm: pxa: Enable for MMP platform pwm: pxa: Add reference manual link and limitations pwm: pxa: Use abrupt shutdown mode pwm: pxa: Remove clk enable/disable from pxa_pwm_config pwm: pxa: Set duty cycle to 0 when disabling PWM pwm: pxa: Remove pxa_pwm_enable/disable pwm: mediatek: Add support for MT7986 ... 
Pull pwm updates from Thierry Reding:
 "Various changes across the board, mostly improvements and cleanups"

* tag 'pwm/for-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (42 commits)
  pwm: pca9685: Convert to i2c's .probe_new()
  pwm: sun4i: Propagate errors in .get_state() to the caller
  pwm: Handle .get_state() failures
  pwm: sprd: Propagate errors in .get_state() to the caller
  pwm: rockchip: Propagate errors in .get_state() to the caller
  pwm: mtk-disp: Propagate errors in .get_state() to the caller
  pwm: imx27: Propagate errors in .get_state() to the caller
  pwm: cros-ec: Propagate errors in .get_state() to the caller
  pwm: crc: Propagate errors in .get_state() to the caller
  leds: qcom-lpg: Propagate errors in .get_state() to the caller
  drm/bridge: ti-sn65dsi86: Propagate errors in .get_state() to the caller
  pwm/tracing: Also record trace events for failed API calls
  pwm: Make .get_state() callback return an error code
  pwm: pxa: Enable for MMP platform
  pwm: pxa: Add reference manual link and limitations
  pwm: pxa: Use abrupt shutdown mode
  pwm: pxa: Remove clk enable/disable from pxa_pwm_config
  pwm: pxa: Set duty cycle to 0 when disabling PWM
  pwm: pxa: Remove pxa_pwm_enable/disable
  pwm: mediatek: Add support for MT7986
  ...
pwm: pca9685: Convert to i2c's .probe_new() 2022-12-06T11:46:31+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2022-12-02T18:35:38+00:00 8fa22f4b88e877c0811d2a0e506cf56755add554 The probe function doesn't make use of the i2c_device_id * parameter so it can be trivially converted. Link: https://lore.kernel.org/r/20221118224540.619276-538-uwe@kleine-koenig.org Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
The probe function doesn't make use of the i2c_device_id * parameter so it
can be trivially converted.

Link: https://lore.kernel.org/r/20221118224540.619276-538-uwe@kleine-koenig.org
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: sun4i: Propagate errors in .get_state() to the caller 2022-12-06T11:46:30+00:00 Andre Przywara andre.przywara@arm.com 2022-12-02T18:35:37+00:00 a08b318a155e77d4c61bbdc28248b347d66f7248 .get_state() can return an error indication now. Make use of it to propagate an impossible prescaler encoding, should that have sneaked in somehow. Also check the return value of clk_get_rate(). That's unlikely to fail, but we use that in two divide operations down in the code, so let's avoid a divide-by-zero condition on the way. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com> Link: https://lore.kernel.org/r/20221201152223.3133-1-andre.przywara@arm.com Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
.get_state() can return an error indication now. Make use of it to
propagate an impossible prescaler encoding, should that have sneaked in
somehow.
Also check the return value of clk_get_rate(). That's unlikely to fail,
but we use that in two divide operations down in the code, so let's
avoid a divide-by-zero condition on the way.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20221201152223.3133-1-andre.przywara@arm.com
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: Handle .get_state() failures 2022-12-06T11:46:29+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2022-12-02T18:35:36+00:00 c73a3107624ddc305483ced13deca9ce8a073783 This suppresses diagnosis for PWM_DEBUG routines and makes sure that pwm->state isn't modified in pwm_device_request() if .get_state() fails. Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-12-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
This suppresses diagnosis for PWM_DEBUG routines and makes sure that
pwm->state isn't modified in pwm_device_request() if .get_state() fails.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-12-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: sprd: Propagate errors in .get_state() to the caller 2022-12-06T11:46:28+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2022-12-02T18:35:35+00:00 500f879843adf329281e418d302e1ad40baa26c3 .get_state() can return an error indication. Make use of it to propagate failing hardware accesses. Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-11-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
.get_state() can return an error indication. Make use of it to propagate
failing hardware accesses.

Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-11-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: rockchip: Propagate errors in .get_state() to the caller 2022-12-06T11:46:28+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2022-12-02T18:35:34+00:00 790a8bae62f701821305dac37a9f6013cde8488f .get_state() can return an error indication. Make use of it to propagate failing hardware accesses. Reviewed-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-10-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
.get_state() can return an error indication. Make use of it to propagate
failing hardware accesses.

Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-10-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: mtk-disp: Propagate errors in .get_state() to the caller 2022-12-06T11:46:27+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2022-12-02T18:35:33+00:00 2f47786ce460206f2ff8ecb7d19352e2307b5511 .get_state() can return an error indication. Make use of it to propagate failing hardware accesses. Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-9-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
.get_state() can return an error indication. Make use of it to propagate
failing hardware accesses.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-9-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
pwm: imx27: Propagate errors in .get_state() to the caller 2022-12-06T11:46:26+00:00 Uwe Kleine-König u.kleine-koenig@pengutronix.de 2022-12-02T18:35:32+00:00 51b9f2fb38bd209bbfa49e1eca2e262667f29e48 .get_state() can return an error indication. Make use of it to propagate failing hardware accesses. Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-8-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com> 
.get_state() can return an error indication. Make use of it to propagate
failing hardware accesses.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20221130152148.2769768-8-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>