[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 001/108] pwm: cros-ec: Change prototype of helper to prepare further changes

[Uwe Kleine-König]

pwm_chip allocation and registration is about to change. For that the number
of PWM devices must be known earlier in cros_ec_pwm_probe(). So make
cros_ec_pwm_get_duty() independant from struct cros_ec_pwm_device which is only
available later.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/pwm/pwm-cros-ec.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 9a8f1b6a4e13..7345ca1c60f0 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -94,9 +94,8 @@ static int cros_ec_pwm_set_duty(struct cros_ec_pwm_device *ec_pwm, u8 index,
 	return cros_ec_cmd_xfer_status(ec, msg);
 }
 
-static int cros_ec_pwm_get_duty(struct cros_ec_pwm_device *ec_pwm, u8 index)
+static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, bool use_pwm_type, u8 index)
 {
-	struct cros_ec_device *ec = ec_pwm->ec;
 	struct {
 		struct cros_ec_command msg;
 		union {
@@ -116,7 +115,7 @@ static int cros_ec_pwm_get_duty(struct cros_ec_pwm_device *ec_pwm, u8 index)
 	msg->insize = sizeof(*resp);
 	msg->outsize = sizeof(*params);
 
-	if (ec_pwm->use_pwm_type) {
+	if (use_pwm_type) {
 		ret = cros_ec_dt_type_to_pwm_type(index, &params->pwm_type);
 		if (ret) {
 			dev_err(ec->dev, "Invalid PWM type index: %d\n", index);
@@ -172,7 +171,7 @@ static int cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	struct cros_ec_pwm *channel = &ec_pwm->channel[pwm->hwpwm];
 	int ret;
 
-	ret = cros_ec_pwm_get_duty(ec_pwm, pwm->hwpwm);
+	ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, pwm->hwpwm);
 	if (ret < 0) {
 		dev_err(chip->dev, "error getting initial duty: %d\n", ret);
 		return ret;
@@ -233,7 +232,7 @@ static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
 
 	/* The index field is only 8 bits */
 	for (i = 0; i <= U8_MAX; i++) {
-		ret = cros_ec_pwm_get_duty(ec_pwm, i);
+		ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, i);
 		/*
 		 * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM
 		 * responses; everything else is treated as an error.
-- 
2.42.0

[PATCH v3 008/108] pwm: cros-ec: 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/pwm/pwm-cros-ec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 7345ca1c60f0..0ce8220646ea 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -173,7 +173,7 @@ static int cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 
 	ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, pwm->hwpwm);
 	if (ret < 0) {
-		dev_err(chip->dev, "error getting initial duty: %d\n", ret);
+		dev_err(pwmchip_parent(chip), "error getting initial duty: %d\n", ret);
 		return ret;
 	}
 
-- 
2.42.0

[PATCH v3 051/108] pwm: cros-ec: Make use of devm_pwmchip_alloc() function

[Uwe Kleine-König]

This prepares the pwm-cros-ec 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.
The probe function had to be changed a bit because the number of PWMs
must be determined before allocation of the pwm_chip and its private
data now.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/pwm/pwm-cros-ec.c | 42 +++++++++++++++++++--------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c
index 0ce8220646ea..290b22423804 100644
--- a/drivers/pwm/pwm-cros-ec.c
+++ b/drivers/pwm/pwm-cros-ec.c
@@ -26,7 +26,6 @@
  */
 struct cros_ec_pwm_device {
 	struct cros_ec_device *ec;
-	struct pwm_chip chip;
 	bool use_pwm_type;
 	struct cros_ec_pwm *channel;
 };
@@ -41,7 +40,7 @@ struct cros_ec_pwm {
 
 static inline struct cros_ec_pwm_device *pwm_to_cros_ec_pwm(struct pwm_chip *chip)
 {
-	return container_of(chip, struct cros_ec_pwm_device, chip);
+	return pwmchip_priv(chip);
 }
 
 static int cros_ec_dt_type_to_pwm_type(u8 dt_index, u8 *pwm_type)
@@ -226,13 +225,13 @@ static const struct pwm_ops cros_ec_pwm_ops = {
  * of PWMs it supports directly, so we have to read the pwm duty cycle for
  * subsequent channels until we get an error.
  */
-static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
+static int cros_ec_num_pwms(struct cros_ec_device *ec, bool use_pwm_type)
 {
 	int i, ret;
 
 	/* The index field is only 8 bits */
 	for (i = 0; i <= U8_MAX; i++) {
-		ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, i);
+		ret = cros_ec_pwm_get_duty(ec, use_pwm_type, i);
 		/*
 		 * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM
 		 * responses; everything else is treated as an error.
@@ -261,35 +260,36 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
 	struct device_node *np = pdev->dev.of_node;
 	struct cros_ec_pwm_device *ec_pwm;
 	struct pwm_chip *chip;
+	bool use_pwm_type = false;
+	unsigned npwm;
 	int ret;
 
 	if (!ec)
 		return dev_err_probe(dev, -EINVAL, "no parent EC device\n");
 
-	ec_pwm = devm_kzalloc(dev, sizeof(*ec_pwm), GFP_KERNEL);
-	if (!ec_pwm)
-		return -ENOMEM;
-	chip = &ec_pwm->chip;
+	if (of_device_is_compatible(np, "google,cros-ec-pwm-type")) {
+		use_pwm_type = true;
+		npwm = CROS_EC_PWM_DT_COUNT;
+	} else {
+		ret = cros_ec_num_pwms(ec, use_pwm_type);
+		if (ret < 0)
+			return dev_err_probe(dev, ret, "Couldn't find PWMs\n");
+		npwm = ret;
+	}
+
+	chip = devm_pwmchip_alloc(dev, npwm, sizeof(*ec_pwm));
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
+
+	ec_pwm = pwm_to_cros_ec_pwm(chip);
+	ec_pwm->use_pwm_type = use_pwm_type;
 	ec_pwm->ec = ec;
 
-	if (of_device_is_compatible(np, "google,cros-ec-pwm-type"))
-		ec_pwm->use_pwm_type = true;
-
 	/* PWM chip */
-	chip->dev = dev;
 	chip->ops = &cros_ec_pwm_ops;
 	chip->of_xlate = cros_ec_pwm_xlate;
 	chip->of_pwm_n_cells = 1;
 
-	if (ec_pwm->use_pwm_type) {
-		chip->npwm = CROS_EC_PWM_DT_COUNT;
-	} else {
-		ret = cros_ec_num_pwms(ec_pwm);
-		if (ret < 0)
-			return dev_err_probe(dev, ret, "Couldn't find PWMs\n");
-		chip->npwm = ret;
-	}
-
 	ec_pwm->channel = devm_kcalloc(dev, chip->npwm, sizeof(*ec_pwm->channel),
 					GFP_KERNEL);
 	if (!ec_pwm->channel)
-- 
2.42.0

Re: [PATCH v3 001/108] pwm: cros-ec: Change prototype of helper to prepare further changes

[Tzung-Bi Shih]

On Tue, Nov 21, 2023 at 02:49:03PM +0100, Uwe Kleine-König wrote:
> @@ -233,7 +232,7 @@ static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
>  
>  	/* The index field is only 8 bits */
>  	for (i = 0; i <= U8_MAX; i++) {
> -		ret = cros_ec_pwm_get_duty(ec_pwm, i);
> +		ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, i);

Or just pass false for `use_pwm_type` because the path:
cros_ec_pwm_probe()
-> !ec_pwm->use_pwm_type
-> cros_ec_num_pwms()

`ec_pwm->use_pwm_type` is always false here.

Re: [PATCH v3 008/108] pwm: cros-ec: Make use of pwmchip_parent() macro

[Tzung-Bi Shih]

On Tue, Nov 21, 2023 at 02:49:10PM +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>

Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>

Re: [PATCH v3 051/108] pwm: cros-ec: Make use of devm_pwmchip_alloc() function

[Tzung-Bi Shih]

On Tue, Nov 21, 2023 at 02:49:53PM +0100, Uwe Kleine-König wrote:
> @@ -41,7 +40,7 @@ struct cros_ec_pwm {
>  
>  static inline struct cros_ec_pwm_device *pwm_to_cros_ec_pwm(struct pwm_chip *chip)
>  {
> -	return container_of(chip, struct cros_ec_pwm_device, chip);
> +	return pwmchip_priv(chip);

Or just replace every `pwm_to_cros_ec_pwm` to `pwmchip_priv`.

> @@ -226,13 +225,13 @@ static const struct pwm_ops cros_ec_pwm_ops = {
>   * of PWMs it supports directly, so we have to read the pwm duty cycle for
>   * subsequent channels until we get an error.
>   */
> -static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
> +static int cros_ec_num_pwms(struct cros_ec_device *ec, bool use_pwm_type)

As replied in previous patch, `use_pwm_type` in the path is always false.

> @@ -261,35 +260,36 @@ static int cros_ec_pwm_probe(struct platform_device *pdev)
>  	struct device_node *np = pdev->dev.of_node;
>  	struct cros_ec_pwm_device *ec_pwm;
>  	struct pwm_chip *chip;
> +	bool use_pwm_type = false;
> +	unsigned npwm;

To be neat, `unsigned int`.

[...]
> +	chip = devm_pwmchip_alloc(dev, npwm, sizeof(*ec_pwm));
> +	if (IS_ERR(chip))
> +		return PTR_ERR(chip);
> +
> +	ec_pwm = pwm_to_cros_ec_pwm(chip);

pwmchip_priv().

Re: [PATCH v3 051/108] pwm: cros-ec: Make use of devm_pwmchip_alloc() function

[Uwe Kleine-König]

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Hello,

On Wed, Nov 22, 2023 at 04:52:44PM +0800, Tzung-Bi Shih wrote:
> On Tue, Nov 21, 2023 at 02:49:53PM +0100, Uwe Kleine-König wrote:
> > @@ -41,7 +40,7 @@ struct cros_ec_pwm {
> >  
> >  static inline struct cros_ec_pwm_device *pwm_to_cros_ec_pwm(struct pwm_chip *chip)
> >  {
> > -	return container_of(chip, struct cros_ec_pwm_device, chip);
> > +	return pwmchip_priv(chip);
> 
> Or just replace every `pwm_to_cros_ec_pwm` to `pwmchip_priv`.

An advantage of the pwm_to_cros_ec_pwm() wrapper is that it yields the
right type. I'd keep it for this series to keep amount of the changes
small (and also because I like to keep the wrapper).

Feel free to propose a patch replacing pwm_to_cros_ec_pwm() by
pwmchip_priv() when this code landed in the mainline.

I'll look into the other things you pointed out. Thanks for your review.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH v3 001/108] pwm: cros-ec: Change prototype of helper to prepare further changes

[Uwe Kleine-König]

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On Wed, Nov 22, 2023 at 04:52:16PM +0800, Tzung-Bi Shih wrote:
> On Tue, Nov 21, 2023 at 02:49:03PM +0100, Uwe Kleine-König wrote:
> > @@ -233,7 +232,7 @@ static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm)
> >  
> >  	/* The index field is only 8 bits */
> >  	for (i = 0; i <= U8_MAX; i++) {
> > -		ret = cros_ec_pwm_get_duty(ec_pwm, i);
> > +		ret = cros_ec_pwm_get_duty(ec_pwm->ec, ec_pwm->use_pwm_type, i);
> 
> Or just pass false for `use_pwm_type` because the path:
> cros_ec_pwm_probe()
> -> !ec_pwm->use_pwm_type
> -> cros_ec_num_pwms()
> 
> `ec_pwm->use_pwm_type` is always false here.

Good catch, that allows to simplify the patch that introduces
devm_pwmchip_alloc() to this driver.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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