[PATCH v3 000/108] pwm: Fix lifetime issues for pwm_chips

[PATCH v3 000/108] pwm: Fix lifetime issues for pwm_chips

[Uwe Kleine-König]

Hello,

this is v3 of the series improving life-time tracking for PWM chips. The
urgency is gone as device links now work as expected and so all
in-kernel users are fine since commit 2e84dc379200 ("driver core:
Release all resources during unbind before updating device links").

However proper lifetime tracking is a precondition to have robust
character device support, as we cannot kill a userspace process if the
used pwm driver goes away.

Changes since v2:

 - Cc: the relevant maintainers for wider testing/review audience
 - Rebase to v6.7-rc1 + https://lore.kernel.org/linux-pwm/20231121112029.gyv3gqirlycysyr4@pengutronix.de
 - Improvements for things pointed out during review and my own
   findings here and there.
 - Implementation for a few more ioctls in the WIP commit that adds
   character support

To go forward I'd like to get in patches up to #103 (i.e. adding
pwmchip_parent() (#2), devm_pwmchip_alloc() (#37) and the conversions of
the drivers to make use of these additions).

The few commits that touch drivers not living in drivers/pwm (i.e. #36,
#100-#103) can go in either via the pwm tree with the rest, or later
---when the used functions are in---via their trees.

After all in-tree drivers are prepared with the patches up to #103, we
can think about when and how we go on with the remaining bits.

Note that patch #104 breaks all drivers that don't use
devm_pwmchip_alloc(), so this is the commit that needs coordination with the
maintainers of

 drivers/gpio/gpio-mvebu.c
 drivers/gpu/drm/bridge/ti-sn65dsi86.c
 drivers/leds/rgb/leds-qcom-lpg.c
 drivers/staging/greybus/pwm.c

The motivation for this series is the last patch. It allows to control a
pwm device via ioctl. Compared to the sysfs API this already now has
some advantages:

- It changes all parameters in a single call.
  This simplifies things similar to the introduction of
  pwm_apply_state(). With sysfs it can happen that you want to
  switch polarity but that's refused because 

	pwm_get_state(mypwm, &state);
	state.polarity = new_value;

  sometimes yield an invalid state, e.g. because state.period is
  in some cases 0 after bootup. Theoretically it can even happen that you have
  to change two parameters before reaching an applicable state, then you're
  stuck with sysfs.

- It's faster than sysfs. In my measurements with stm32 about a factor
  4.

A userspace lib to make use of this can be found at
https://git.kernel.org/pub/scm/linux/kernel/git/ukleinek/libpwm.git/ .
It makes use of the character devices if available and falls back to
sysfs. So it's somewhat useful already now.

Best regards
Uwe

Uwe Kleine-König (108):
  pwm: cros-ec: Change prototype of helper to prepare further changes
  pwm: Provide a macro to get the parent device of a given chip
  pwm: ab8500: Make use of pwmchip_parent() macro
  pwm: atmel: Make use of pwmchip_parent() macro
  pwm: atmel-tcb: Make use of pwmchip_parent() macro
  pwm: bcm-kona: Make use of pwmchip_parent() macro
  pwm: crc: Make use of pwmchip_parent() macro
  pwm: cros-ec: Make use of pwmchip_parent() macro
  pwm: dwc: Make use of pwmchip_parent() macro
  pwm: ep93xx: Make use of pwmchip_parent() macro
  pwm: fsl-ftm: Make use of pwmchip_parent() macro
  pwm: img: Make use of parent device pointer in driver data
  pwm: imx27: Make use of pwmchip_parent() macro
  pwm: jz4740: Make use of pwmchip_parent() macro
  pwm: lpc18xx-sct: Make use of parent device pointer in driver data
  pwm: lpss: Make use of pwmchip_parent() macro
  pwm: mediatek: Make use of pwmchip_parent() macro
  pwm: meson: Make use of pwmchip_parent() macro
  pwm: mtk-disp: Make use of pwmchip_parent() macro
  pwm: omap: Make use of pwmchip_parent() macro
  pwm: pca9685: Store parent device in driver data
  pwm: raspberrypi-poe: Make use of pwmchip_parent() macro
  pwm: rcar: Make use of pwmchip_parent() macro
  pwm: rz-mtu3: Make use of pwmchip_parent() macro
  pwm: samsung: Make use of pwmchip_parent() macro
  pwm: sifive: Make use of pwmchip_parent() macro
  pwm: stm32-lp: Make use of pwmchip_parent() macro
  pwm: stm32: Make use of pwmchip_parent() macro
  pwm: stmpe: Make use of pwmchip_parent() macro
  pwm: sun4i: Make use of pwmchip_parent() macro
  pwm: tiecap: Make use of pwmchip_parent() macro
  pwm: tiehrpwm: Make use of pwmchip_parent() macro
  pwm: twl-led: Make use of pwmchip_parent() macro
  pwm: twl: Make use of pwmchip_parent() macro
  pwm: vt8500: Make use of pwmchip_parent() macro
  staging: greybus: pwm: Make use of pwmchip_parent() macro
  pwm: Provide devm_pwmchip_alloc() function
  pwm: ab8500: Make use of devm_pwmchip_alloc() function
  pwm: apple: Make use of devm_pwmchip_alloc() function
  pwm: atmel-hlcdc: Make use of devm_pwmchip_alloc() function
  pwm: atmel: Make use of devm_pwmchip_alloc() function
  pwm: atmel-tcb: Make use of devm_pwmchip_alloc() function
  pwm: bcm2835: Make use of devm_pwmchip_alloc() function
  pwm: bcm-iproc: Make use of devm_pwmchip_alloc() function
  pwm: bcm-kona: Make use of devm_pwmchip_alloc() function
  pwm: berlin: Make use of devm_pwmchip_alloc() function
  pwm: brcmstb: Make use of devm_pwmchip_alloc() function
  pwm: clk: Make use of devm_pwmchip_alloc() function
  pwm: clps711x: Make use of devm_pwmchip_alloc() function
  pwm: crc: Make use of devm_pwmchip_alloc() function
  pwm: cros-ec: Make use of devm_pwmchip_alloc() function
  pwm: dwc: Make use of devm_pwmchip_alloc() function
  pwm: ep93xx: Make use of devm_pwmchip_alloc() function
  pwm: fsl-ftm: Make use of devm_pwmchip_alloc() function
  pwm: hibvt: Make use of devm_pwmchip_alloc() function
  pwm: img: Make use of devm_pwmchip_alloc() function
  pwm: imx1: Make use of devm_pwmchip_alloc() function
  pwm: imx27: Make use of devm_pwmchip_alloc() function
  pwm: imx-tpm: Make use of devm_pwmchip_alloc() function
  pwm: intel-lgm: Make use of devm_pwmchip_alloc() function
  pwm: iqs620a: Make use of devm_pwmchip_alloc() function
  pwm: jz4740: Make use of devm_pwmchip_alloc() function
  pwm: keembay: Make use of devm_pwmchip_alloc() function
  pwm: lp3943: Make use of devm_pwmchip_alloc() function
  pwm: lpc18xx-sct: Make use of devm_pwmchip_alloc() function
  pwm: lpc32xx: Make use of devm_pwmchip_alloc() function
  pwm: lpss-*: Make use of devm_pwmchip_alloc() function
  pwm: mediatek: Make use of devm_pwmchip_alloc() function
  pwm: meson: Make use of devm_pwmchip_alloc() function
  pwm: microchip-core: Make use of devm_pwmchip_alloc() function
  pwm: mtk-disp: Make use of devm_pwmchip_alloc() function
  pwm: mxs: Make use of devm_pwmchip_alloc() function
  pwm: ntxec: Make use of devm_pwmchip_alloc() function
  pwm: omap-dmtimer: Make use of devm_pwmchip_alloc() function
  pwm: pca9685: Make use of devm_pwmchip_alloc() function
  pwm: pxa: Make use of devm_pwmchip_alloc() function
  pwm: raspberrypi-poe: Make use of devm_pwmchip_alloc() function
  pwm: rcar: Make use of devm_pwmchip_alloc() function
  pwm: renesas-tpu: Make use of devm_pwmchip_alloc() function
  pwm: rockchip: Make use of devm_pwmchip_alloc() function
  pwm: rz-mtu3: Make use of devm_pwmchip_alloc() function
  pwm: samsung: Make use of devm_pwmchip_alloc() function
  pwm: sifive: Make use of devm_pwmchip_alloc() function
  pwm: sl28cpld: Make use of devm_pwmchip_alloc() function
  pwm: spear: Make use of devm_pwmchip_alloc() function
  pwm: sprd: Make use of devm_pwmchip_alloc() function
  pwm: sti: Make use of devm_pwmchip_alloc() function
  pwm: stm32-lp: Make use of devm_pwmchip_alloc() function
  pwm: stm32: Make use of devm_pwmchip_alloc() function
  pwm: stmpe: Make use of devm_pwmchip_alloc() function
  pwm: sun4i: Make use of devm_pwmchip_alloc() function
  pwm: sunplus: Make use of devm_pwmchip_alloc() function
  pwm: tegra: Make use of devm_pwmchip_alloc() function
  pwm: tiecap: Make use of devm_pwmchip_alloc() function
  pwm: twl-led: Make use of devm_pwmchip_alloc() function
  pwm: twl: Make use of devm_pwmchip_alloc() function
  pwm: visconti: Make use of devm_pwmchip_alloc() function
  pwm: vt8500: Make use of devm_pwmchip_alloc() function
  pwm: xilinx: Make use of devm_pwmchip_alloc() function
  gpio: mvebu: Make use of devm_pwmchip_alloc() function
  drm/bridge: ti-sn65dsi86: Make use of devm_pwmchip_alloc() function
  leds: qcom-lpg: Make use of devm_pwmchip_alloc() function
  staging: greybus: pwm: Make use of devm_pwmchip_alloc() function
  pwm: Ensure that pwm_chips are allocated using pwmchip_alloc()
  pwm: Ensure a struct pwm has the same lifetime as its pwm_chip
  pwm: Ensure the memory backing a PWM chip isn't freed while used
  pwm: Add more locking
  WIP: pwm: Add support for pwmchip devices for faster and easier
    userspace access

 .../driver-api/driver-model/devres.rst        |   1 +
 Documentation/driver-api/pwm.rst              |  10 +-
 drivers/gpio/gpio-mvebu.c                     |  18 +-
 drivers/gpu/drm/bridge/ti-sn65dsi86.c         |  25 +-
 drivers/leds/rgb/leds-qcom-lpg.c              |  30 +-
 drivers/pwm/Kconfig                           |   4 -
 drivers/pwm/Makefile                          |   3 +-
 drivers/pwm/core.c                            | 480 +++++++++++++++---
 drivers/pwm/pwm-ab8500.c                      |  36 +-
 drivers/pwm/pwm-apple.c                       |  18 +-
 drivers/pwm/pwm-atmel-hlcdc.c                 |  35 +-
 drivers/pwm/pwm-atmel-tcb.c                   |  26 +-
 drivers/pwm/pwm-atmel.c                       |  37 +-
 drivers/pwm/pwm-bcm-iproc.c                   |  19 +-
 drivers/pwm/pwm-bcm-kona.c                    |  21 +-
 drivers/pwm/pwm-bcm2835.c                     |  17 +-
 drivers/pwm/pwm-berlin.c                      |  29 +-
 drivers/pwm/pwm-brcmstb.c                     |  17 +-
 drivers/pwm/pwm-clk.c                         |  27 +-
 drivers/pwm/pwm-clps711x.c                    |  21 +-
 drivers/pwm/pwm-crc.c                         |  26 +-
 drivers/pwm/pwm-cros-ec.c                     |  51 +-
 drivers/pwm/pwm-dwc-core.c                    |  25 +-
 drivers/pwm/pwm-dwc.c                         |  18 +-
 drivers/pwm/pwm-dwc.h                         |   9 +-
 drivers/pwm/pwm-ep93xx.c                      |  21 +-
 drivers/pwm/pwm-fsl-ftm.c                     |  48 +-
 drivers/pwm/pwm-hibvt.c                       |  25 +-
 drivers/pwm/pwm-img.c                         |  51 +-
 drivers/pwm/pwm-imx-tpm.c                     |  34 +-
 drivers/pwm/pwm-imx1.c                        |  17 +-
 drivers/pwm/pwm-imx27.c                       |  26 +-
 drivers/pwm/pwm-intel-lgm.c                   |  17 +-
 drivers/pwm/pwm-iqs620a.c                     |  37 +-
 drivers/pwm/pwm-jz4740.c                      |  35 +-
 drivers/pwm/pwm-keembay.c                     |  17 +-
 drivers/pwm/pwm-lp3943.c                      |  17 +-
 drivers/pwm/pwm-lpc18xx-sct.c                 |  35 +-
 drivers/pwm/pwm-lpc32xx.c                     |  19 +-
 drivers/pwm/pwm-lpss-pci.c                    |  10 +-
 drivers/pwm/pwm-lpss-platform.c               |  10 +-
 drivers/pwm/pwm-lpss.c                        |  34 +-
 drivers/pwm/pwm-lpss.h                        |   1 -
 drivers/pwm/pwm-mediatek.c                    |  28 +-
 drivers/pwm/pwm-meson.c                       |  57 ++-
 drivers/pwm/pwm-microchip-core.c              |  17 +-
 drivers/pwm/pwm-mtk-disp.c                    |  25 +-
 drivers/pwm/pwm-mxs.c                         |  32 +-
 drivers/pwm/pwm-ntxec.c                       |  30 +-
 drivers/pwm/pwm-omap-dmtimer.c                |  46 +-
 drivers/pwm/pwm-pca9685.c                     |  98 ++--
 drivers/pwm/pwm-pxa.c                         |  21 +-
 drivers/pwm/pwm-raspberrypi-poe.c             |  20 +-
 drivers/pwm/pwm-rcar.c                        |  25 +-
 drivers/pwm/pwm-renesas-tpu.c                 |  18 +-
 drivers/pwm/pwm-rockchip.c                    |  24 +-
 drivers/pwm/pwm-rz-mtu3.c                     |  38 +-
 drivers/pwm/pwm-samsung.c                     |  56 +-
 drivers/pwm/pwm-sifive.c                      |  30 +-
 drivers/pwm/pwm-sl28cpld.c                    |  13 +-
 drivers/pwm/pwm-spear.c                       |  17 +-
 drivers/pwm/pwm-sprd.c                        |  50 +-
 drivers/pwm/pwm-sti.c                         |  34 +-
 drivers/pwm/pwm-stm32-lp.c                    |  29 +-
 drivers/pwm/pwm-stm32.c                       |  53 +-
 drivers/pwm/pwm-stmpe.c                       |  58 ++-
 drivers/pwm/pwm-sun4i.c                       |  38 +-
 drivers/pwm/pwm-sunplus.c                     |  17 +-
 drivers/pwm/pwm-tegra.c                       |  27 +-
 drivers/pwm/pwm-tiecap.c                      |  55 +-
 drivers/pwm/pwm-tiehrpwm.c                    |  72 +--
 drivers/pwm/pwm-twl-led.c                     |  58 ++-
 drivers/pwm/pwm-twl.c                         |  50 +-
 drivers/pwm/pwm-visconti.c                    |  17 +-
 drivers/pwm/pwm-vt8500.c                      |  41 +-
 drivers/pwm/pwm-xilinx.c                      |  34 +-
 drivers/pwm/sysfs.c                           |  64 +--
 drivers/staging/greybus/pwm.c                 | 130 ++---
 include/linux/platform_data/x86/pwm-lpss.h    |   4 +-
 include/linux/pwm.h                           |  36 +-
 include/uapi/linux/pwm.h                      |  23 +
 81 files changed, 1651 insertions(+), 1291 deletions(-)
 create mode 100644 include/uapi/linux/pwm.h

base-commit: 869de350ff3834145273a6d39faedea878c6715a
-- 
2.42.0

[PATCH v3 036/108] staging: greybus: pwm: Make use of pwmchip_parent() macro

[Uwe Kleine-König]

struct pwm_chip::dev is about to change. To not have to touch this
driver in the same commit as struct pwm_chip::dev, use the macro
provided for exactly this purpose.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/staging/greybus/pwm.c | 55 +++++++++++++++++------------------
 1 file changed, 26 insertions(+), 29 deletions(-)

diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c
index a3cb68cfa0f9..75e0518791d8 100644
--- a/drivers/staging/greybus/pwm.c
+++ b/drivers/staging/greybus/pwm.c
@@ -17,7 +17,6 @@
 struct gb_pwm_chip {
 	struct gb_connection	*connection;
 	u8			pwm_max;	/* max pwm number */
-
 	struct pwm_chip		chip;
 };
 
@@ -39,9 +38,9 @@ static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
 	return 0;
 }
 
-static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
-				     u8 which)
+static int gb_pwm_activate_operation(struct pwm_chip *chip, u8 which)
 {
+	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 	struct gb_pwm_activate_request request;
 	struct gbphy_device *gbphy_dev;
 	int ret;
@@ -51,7 +50,7 @@ static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
 
 	request.which = which;
 
-	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
 	ret = gbphy_runtime_get_sync(gbphy_dev);
 	if (ret)
 		return ret;
@@ -64,9 +63,10 @@ static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
 	return ret;
 }
 
-static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
+static int gb_pwm_deactivate_operation(struct pwm_chip *chip,
 				       u8 which)
 {
+	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 	struct gb_pwm_deactivate_request request;
 	struct gbphy_device *gbphy_dev;
 	int ret;
@@ -76,7 +76,7 @@ static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
 
 	request.which = which;
 
-	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
 	ret = gbphy_runtime_get_sync(gbphy_dev);
 	if (ret)
 		return ret;
@@ -89,9 +89,10 @@ static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
 	return ret;
 }
 
-static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
+static int gb_pwm_config_operation(struct pwm_chip *chip,
 				   u8 which, u32 duty, u32 period)
 {
+	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 	struct gb_pwm_config_request request;
 	struct gbphy_device *gbphy_dev;
 	int ret;
@@ -103,7 +104,7 @@ static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
 	request.duty = cpu_to_le32(duty);
 	request.period = cpu_to_le32(period);
 
-	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
 	ret = gbphy_runtime_get_sync(gbphy_dev);
 	if (ret)
 		return ret;
@@ -116,9 +117,10 @@ static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
 	return ret;
 }
 
-static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
+static int gb_pwm_set_polarity_operation(struct pwm_chip *chip,
 					 u8 which, u8 polarity)
 {
+	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 	struct gb_pwm_polarity_request request;
 	struct gbphy_device *gbphy_dev;
 	int ret;
@@ -129,7 +131,7 @@ static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
 	request.which = which;
 	request.polarity = polarity;
 
-	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
 	ret = gbphy_runtime_get_sync(gbphy_dev);
 	if (ret)
 		return ret;
@@ -142,9 +144,9 @@ static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
 	return ret;
 }
 
-static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
-				   u8 which)
+static int gb_pwm_enable_operation(struct pwm_chip *chip, u8 which)
 {
+	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 	struct gb_pwm_enable_request request;
 	struct gbphy_device *gbphy_dev;
 	int ret;
@@ -154,7 +156,7 @@ static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
 
 	request.which = which;
 
-	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
 	ret = gbphy_runtime_get_sync(gbphy_dev);
 	if (ret)
 		return ret;
@@ -167,9 +169,9 @@ static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
 	return ret;
 }
 
-static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
-				    u8 which)
+static int gb_pwm_disable_operation(struct pwm_chip *chip, u8 which)
 {
+	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 	struct gb_pwm_disable_request request;
 	struct gbphy_device *gbphy_dev;
 	int ret;
@@ -182,7 +184,7 @@ static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
 	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
 				&request, sizeof(request), NULL, 0);
 
-	gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
+	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
 	gbphy_runtime_put_autosuspend(gbphy_dev);
 
 	return ret;
@@ -190,19 +192,15 @@ static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
 
 static int gb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
-
-	return gb_pwm_activate_operation(pwmc, pwm->hwpwm);
+	return gb_pwm_activate_operation(chip, pwm->hwpwm);
 };
 
 static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
-	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
-
 	if (pwm_is_enabled(pwm))
-		dev_warn(chip->dev, "freeing PWM device without disabling\n");
+		dev_warn(pwmchip_parent(chip), "freeing PWM device without disabling\n");
 
-	gb_pwm_deactivate_operation(pwmc, pwm->hwpwm);
+	gb_pwm_deactivate_operation(chip, pwm->hwpwm);
 }
 
 static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
@@ -212,22 +210,21 @@ static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	bool enabled = pwm->state.enabled;
 	u64 period = state->period;
 	u64 duty_cycle = state->duty_cycle;
-	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 
 	/* Set polarity */
 	if (state->polarity != pwm->state.polarity) {
 		if (enabled) {
-			gb_pwm_disable_operation(pwmc, pwm->hwpwm);
+			gb_pwm_disable_operation(chip, pwm->hwpwm);
 			enabled = false;
 		}
-		err = gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, state->polarity);
+		err = gb_pwm_set_polarity_operation(chip, pwm->hwpwm, state->polarity);
 		if (err)
 			return err;
 	}
 
 	if (!state->enabled) {
 		if (enabled)
-			gb_pwm_disable_operation(pwmc, pwm->hwpwm);
+			gb_pwm_disable_operation(chip, pwm->hwpwm);
 		return 0;
 	}
 
@@ -243,13 +240,13 @@ static int gb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	if (duty_cycle > period)
 		duty_cycle = period;
 
-	err = gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_cycle, period);
+	err = gb_pwm_config_operation(chip, pwm->hwpwm, duty_cycle, period);
 	if (err)
 		return err;
 
 	/* enable/disable */
 	if (!enabled)
-		return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
+		return gb_pwm_enable_operation(chip, pwm->hwpwm);
 
 	return 0;
 }
-- 
2.42.0

Re: [PATCH v3 036/108] staging: greybus: pwm: Make use of pwmchip_parent() macro

[Greg Kroah-Hartman]

On Tue, Nov 21, 2023 at 02:49:38PM +0100, Uwe Kleine-König wrote:
> struct pwm_chip::dev is about to change. To not have to touch this
> driver in the same commit as struct pwm_chip::dev, use the macro
> provided for exactly this purpose.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/staging/greybus/pwm.c | 55 +++++++++++++++++------------------
>  1 file changed, 26 insertions(+), 29 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

[PATCH v3 103/108] staging: greybus: pwm: Make use of devm_pwmchip_alloc() function

[Uwe Kleine-König]

This prepares the greybus pwm driver to further changes of the pwm core
outlined in the commit introducing devm_pwmchip_alloc(). There is no
intended semantical change and the driver should behave as before.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/staging/greybus/pwm.c | 75 ++++++++++-------------------------
 1 file changed, 20 insertions(+), 55 deletions(-)

diff --git a/drivers/staging/greybus/pwm.c b/drivers/staging/greybus/pwm.c
index 75e0518791d8..897a1f1ea9d2 100644
--- a/drivers/staging/greybus/pwm.c
+++ b/drivers/staging/greybus/pwm.c
@@ -16,26 +16,11 @@
 
 struct gb_pwm_chip {
 	struct gb_connection	*connection;
-	u8			pwm_max;	/* max pwm number */
-	struct pwm_chip		chip;
 };
 
 static inline struct gb_pwm_chip *pwm_chip_to_gb_pwm_chip(struct pwm_chip *chip)
 {
-	return container_of(chip, struct gb_pwm_chip, chip);
-}
-
-static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
-{
-	struct gb_pwm_count_response response;
-	int ret;
-
-	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
-				NULL, 0, &response, sizeof(response));
-	if (ret)
-		return ret;
-	pwmc->pwm_max = response.count;
-	return 0;
+	return pwmchip_priv(chip);
 }
 
 static int gb_pwm_activate_operation(struct pwm_chip *chip, u8 which)
@@ -45,9 +30,6 @@ static int gb_pwm_activate_operation(struct pwm_chip *chip, u8 which)
 	struct gbphy_device *gbphy_dev;
 	int ret;
 
-	if (which > pwmc->pwm_max)
-		return -EINVAL;
-
 	request.which = which;
 
 	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
@@ -71,9 +53,6 @@ static int gb_pwm_deactivate_operation(struct pwm_chip *chip,
 	struct gbphy_device *gbphy_dev;
 	int ret;
 
-	if (which > pwmc->pwm_max)
-		return -EINVAL;
-
 	request.which = which;
 
 	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
@@ -97,9 +76,6 @@ static int gb_pwm_config_operation(struct pwm_chip *chip,
 	struct gbphy_device *gbphy_dev;
 	int ret;
 
-	if (which > pwmc->pwm_max)
-		return -EINVAL;
-
 	request.which = which;
 	request.duty = cpu_to_le32(duty);
 	request.period = cpu_to_le32(period);
@@ -125,9 +101,6 @@ static int gb_pwm_set_polarity_operation(struct pwm_chip *chip,
 	struct gbphy_device *gbphy_dev;
 	int ret;
 
-	if (which > pwmc->pwm_max)
-		return -EINVAL;
-
 	request.which = which;
 	request.polarity = polarity;
 
@@ -151,9 +124,6 @@ static int gb_pwm_enable_operation(struct pwm_chip *chip, u8 which)
 	struct gbphy_device *gbphy_dev;
 	int ret;
 
-	if (which > pwmc->pwm_max)
-		return -EINVAL;
-
 	request.which = which;
 
 	gbphy_dev = to_gbphy_dev(pwmchip_parent(chip));
@@ -176,9 +146,6 @@ static int gb_pwm_disable_operation(struct pwm_chip *chip, u8 which)
 	struct gbphy_device *gbphy_dev;
 	int ret;
 
-	if (which > pwmc->pwm_max)
-		return -EINVAL;
-
 	request.which = which;
 
 	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
@@ -263,38 +230,37 @@ static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
 	struct gb_connection *connection;
 	struct gb_pwm_chip *pwmc;
 	struct pwm_chip *chip;
+	struct gb_pwm_count_response response;
 	int ret;
 
-	pwmc = kzalloc(sizeof(*pwmc), GFP_KERNEL);
-	if (!pwmc)
-		return -ENOMEM;
-
 	connection = gb_connection_create(gbphy_dev->bundle,
 					  le16_to_cpu(gbphy_dev->cport_desc->id),
 					  NULL);
-	if (IS_ERR(connection)) {
-		ret = PTR_ERR(connection);
-		goto exit_pwmc_free;
+	if (IS_ERR(connection))
+		return PTR_ERR(connection);
+
+	ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
+				NULL, 0, &response, sizeof(response));
+	if (ret)
+		goto exit_connection_destroy;
+
+	chip = devm_pwmchip_alloc(&gbphy_dev->dev, response.count, sizeof(*pwmc));
+	if (IS_ERR(chip)) {
+		ret = PTR_ERR(chip);
+		goto exit_connection_destroy;
 	}
 
+	pwmc = pwmchip_priv(chip);
 	pwmc->connection = connection;
+
 	gb_connection_set_data(connection, pwmc);
-	gb_gbphy_set_data(gbphy_dev, pwmc);
+	gb_gbphy_set_data(gbphy_dev, chip);
 
 	ret = gb_connection_enable(connection);
 	if (ret)
 		goto exit_connection_destroy;
 
-	/* Query number of pwms present */
-	ret = gb_pwm_count_operation(pwmc);
-	if (ret)
-		goto exit_connection_disable;
-
-	chip = &pwmc->chip;
-
-	chip->dev = &gbphy_dev->dev;
 	chip->ops = &gb_pwm_ops;
-	chip->npwm = pwmc->pwm_max + 1;
 
 	ret = pwmchip_add(chip);
 	if (ret) {
@@ -310,14 +276,13 @@ static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
 	gb_connection_disable(connection);
 exit_connection_destroy:
 	gb_connection_destroy(connection);
-exit_pwmc_free:
-	kfree(pwmc);
 	return ret;
 }
 
 static void gb_pwm_remove(struct gbphy_device *gbphy_dev)
 {
-	struct gb_pwm_chip *pwmc = gb_gbphy_get_data(gbphy_dev);
+	struct pwm_chip *chip = gb_gbphy_get_data(gbphy_dev);
+	struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 	struct gb_connection *connection = pwmc->connection;
 	int ret;
 
@@ -325,7 +290,7 @@ static void gb_pwm_remove(struct gbphy_device *gbphy_dev)
 	if (ret)
 		gbphy_runtime_get_noresume(gbphy_dev);
 
-	pwmchip_remove(&pwmc->chip);
+	pwmchip_remove(chip);
 	gb_connection_disable(connection);
 	gb_connection_destroy(connection);
 	kfree(pwmc);
-- 
2.42.0

Re: [PATCH v3 103/108] staging: greybus: pwm: Make use of devm_pwmchip_alloc() function

[Greg Kroah-Hartman]

On Tue, Nov 21, 2023 at 02:50:45PM +0100, Uwe Kleine-König wrote:
> This prepares the greybus pwm driver to further changes of the pwm core
> outlined in the commit introducing devm_pwmchip_alloc(). There is no
> intended semantical change and the driver should behave as before.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> ---
>  drivers/staging/greybus/pwm.c | 75 ++++++++++-------------------------
>  1 file changed, 20 insertions(+), 55 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>