Merge tag 'pwm/for-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This set of changes contains a new driver for SiFive SoCs as well as
  enhancements to the core (device links are used to track dependencies
  between PWM providers and consumers, support for PWM controllers via
  ACPI, sysfs will now suspend/resume PWMs that it has claimed) and
  various existing drivers"

* tag 'pwm/for-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (37 commits)
  pwm: fsl-ftm: Make sure to unlock mutex on failure
  pwm: fsl-ftm: Use write protection for prescaler & polarity
  pwm: fsl-ftm: More relaxed permissions for updating period
  pwm: atmel-hlcdc: Add compatible for SAM9X60 HLCDC's PWM
  pwm: bcm2835: Improve precision of PWM
  leds: pwm: Support ACPI via firmware-node framework
  pwm: Add support referencing PWMs from ACPI
  pwm: rcar: Remove suspend/resume support
  pwm: sysfs: Add suspend/resume support
  pwm: Add power management descriptions
  pwm: meson: Add documentation to the driver
  pwm: meson: Add support PWM_POLARITY_INVERSED when disabling
  pwm: meson: Don't cache struct pwm_state internally
  pwm: meson: Read the full hardware state in meson_pwm_get_state()
  pwm: meson: Simplify the calculation of the pre-divider and count
  pwm: meson: Move pwm_set_chip_data() to meson_pwm_request()
  pwm: meson: Add the per-channel register offsets and bits in a struct
  pwm: meson: Add the meson_pwm_channel data to struct meson_pwm
  pwm: meson: Pass struct pwm_device to meson_pwm_calc()
  pwm: meson: Don't duplicate the polarity internally
  ...

1 files changed, 102 insertions, 0 deletions

diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c
index bf6823fe0812..2389b8669846 100644
--- a/drivers/pwm/sysfs.c
+++ b/drivers/pwm/sysfs.c
@@ -18,6 +18,7 @@ struct pwm_export {
 	struct device child;
 	struct pwm_device *pwm;
 	struct mutex lock;
+	struct pwm_state suspend;
 };
 
 static struct pwm_export *child_to_pwm_export(struct device *child)
@@ -372,10 +373,111 @@ static struct attribute *pwm_chip_attrs[] = {
 };
 ATTRIBUTE_GROUPS(pwm_chip);
 
+/* takes export->lock on success */
+static struct pwm_export *pwm_class_get_state(struct device *parent,
+					      struct pwm_device *pwm,
+					      struct pwm_state *state)
+{
+	struct device *child;
+	struct pwm_export *export;
+
+	if (!test_bit(PWMF_EXPORTED, &pwm->flags))
+		return NULL;
+
+	child = device_find_child(parent, pwm, pwm_unexport_match);
+	if (!child)
+		return NULL;
+
+	export = child_to_pwm_export(child);
+	put_device(child);	/* for device_find_child() */
+
+	mutex_lock(&export->lock);
+	pwm_get_state(pwm, state);
+
+	return export;
+}
+
+static int pwm_class_apply_state(struct pwm_export *export,
+				 struct pwm_device *pwm,
+				 struct pwm_state *state)
+{
+	int ret = pwm_apply_state(pwm, state);
+
+	/* release lock taken in pwm_class_get_state */
+	mutex_unlock(&export->lock);
+
+	return ret;
+}
+
+static int pwm_class_resume_npwm(struct device *parent, unsigned int npwm)
+{
+	struct pwm_chip *chip = dev_get_drvdata(parent);
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < npwm; i++) {
+		struct pwm_device *pwm = &chip->pwms[i];
+		struct pwm_state state;
+		struct pwm_export *export;
+
+		export = pwm_class_get_state(parent, pwm, &state);
+		if (!export)
+			continue;
+
+		state.enabled = export->suspend.enabled;
+		ret = pwm_class_apply_state(export, pwm, &state);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
+static int __maybe_unused pwm_class_suspend(struct device *parent)
+{
+	struct pwm_chip *chip = dev_get_drvdata(parent);
+	unsigned int i;
+	int ret = 0;
+
+	for (i = 0; i < chip->npwm; i++) {
+		struct pwm_device *pwm = &chip->pwms[i];
+		struct pwm_state state;
+		struct pwm_export *export;
+
+		export = pwm_class_get_state(parent, pwm, &state);
+		if (!export)
+			continue;
+
+		export->suspend = state;
+		state.enabled = false;
+		ret = pwm_class_apply_state(export, pwm, &state);
+		if (ret < 0) {
+			/*
+			 * roll back the PWM devices that were disabled by
+			 * this suspend function.
+			 */
+			pwm_class_resume_npwm(parent, i);
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static int __maybe_unused pwm_class_resume(struct device *parent)
+{
+	struct pwm_chip *chip = dev_get_drvdata(parent);
+
+	return pwm_class_resume_npwm(parent, chip->npwm);
+}
+
+static SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
+
 static struct class pwm_class = {
 	.name = "pwm",
 	.owner = THIS_MODULE,
 	.dev_groups = pwm_chip_groups,
+	.pm = &pwm_class_pm_ops,
 };
 
 static int pwmchip_sysfs_match(struct device *parent, const void *data)