if PWM
-config PWM_SYSFS
- bool
- default y if SYSFS
-
config PWM_DEBUG
bool "PWM lowlevel drivers additional checks and debug messages"
depends on DEBUG_KERNEL
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_PWM) += core.o
-obj-$(CONFIG_PWM_SYSFS) += sysfs.o
obj-$(CONFIG_PWM_AB8500) += pwm-ab8500.o
obj-$(CONFIG_PWM_APPLE) += pwm-apple.o
obj-$(CONFIG_PWM_ATMEL) += pwm-atmel.o
}
EXPORT_SYMBOL_GPL(of_pwm_single_xlate);
+struct pwm_export {
+ struct device pwm_dev;
+ struct pwm_device *pwm;
+ struct mutex lock;
+ struct pwm_state suspend;
+};
+
+static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev)
+{
+ return dev_get_drvdata(pwmchip_dev);
+}
+
+static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev)
+{
+ return container_of(pwm_dev, struct pwm_export, pwm_dev);
+}
+
+static inline struct pwm_device *pwm_from_dev(struct device *pwm_dev)
+{
+ struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+
+ return export->pwm;
+}
+
+static ssize_t period_show(struct device *pwm_dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+ struct pwm_state state;
+
+ pwm_get_state(pwm, &state);
+
+ return sysfs_emit(buf, "%llu\n", state.period);
+}
+
+static ssize_t period_store(struct device *pwm_dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+ struct pwm_device *pwm = export->pwm;
+ struct pwm_state state;
+ u64 val;
+ int ret;
+
+ ret = kstrtou64(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ mutex_lock(&export->lock);
+ pwm_get_state(pwm, &state);
+ state.period = val;
+ ret = pwm_apply_might_sleep(pwm, &state);
+ mutex_unlock(&export->lock);
+
+ return ret ? : size;
+}
+
+static ssize_t duty_cycle_show(struct device *pwm_dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+ struct pwm_state state;
+
+ pwm_get_state(pwm, &state);
+
+ return sysfs_emit(buf, "%llu\n", state.duty_cycle);
+}
+
+static ssize_t duty_cycle_store(struct device *pwm_dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+ struct pwm_device *pwm = export->pwm;
+ struct pwm_state state;
+ u64 val;
+ int ret;
+
+ ret = kstrtou64(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ mutex_lock(&export->lock);
+ pwm_get_state(pwm, &state);
+ state.duty_cycle = val;
+ ret = pwm_apply_might_sleep(pwm, &state);
+ mutex_unlock(&export->lock);
+
+ return ret ? : size;
+}
+
+static ssize_t enable_show(struct device *pwm_dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+ struct pwm_state state;
+
+ pwm_get_state(pwm, &state);
+
+ return sysfs_emit(buf, "%d\n", state.enabled);
+}
+
+static ssize_t enable_store(struct device *pwm_dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+ struct pwm_device *pwm = export->pwm;
+ struct pwm_state state;
+ int val, ret;
+
+ ret = kstrtoint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ mutex_lock(&export->lock);
+
+ pwm_get_state(pwm, &state);
+
+ switch (val) {
+ case 0:
+ state.enabled = false;
+ break;
+ case 1:
+ state.enabled = true;
+ break;
+ default:
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ ret = pwm_apply_might_sleep(pwm, &state);
+
+unlock:
+ mutex_unlock(&export->lock);
+ return ret ? : size;
+}
+
+static ssize_t polarity_show(struct device *pwm_dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+ const char *polarity = "unknown";
+ struct pwm_state state;
+
+ pwm_get_state(pwm, &state);
+
+ switch (state.polarity) {
+ case PWM_POLARITY_NORMAL:
+ polarity = "normal";
+ break;
+
+ case PWM_POLARITY_INVERSED:
+ polarity = "inversed";
+ break;
+ }
+
+ return sysfs_emit(buf, "%s\n", polarity);
+}
+
+static ssize_t polarity_store(struct device *pwm_dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+ struct pwm_device *pwm = export->pwm;
+ enum pwm_polarity polarity;
+ struct pwm_state state;
+ int ret;
+
+ if (sysfs_streq(buf, "normal"))
+ polarity = PWM_POLARITY_NORMAL;
+ else if (sysfs_streq(buf, "inversed"))
+ polarity = PWM_POLARITY_INVERSED;
+ else
+ return -EINVAL;
+
+ mutex_lock(&export->lock);
+ pwm_get_state(pwm, &state);
+ state.polarity = polarity;
+ ret = pwm_apply_might_sleep(pwm, &state);
+ mutex_unlock(&export->lock);
+
+ return ret ? : size;
+}
+
+static ssize_t capture_show(struct device *pwm_dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct pwm_device *pwm = pwm_from_dev(pwm_dev);
+ struct pwm_capture result;
+ int ret;
+
+ ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
+ if (ret)
+ return ret;
+
+ return sysfs_emit(buf, "%u %u\n", result.period, result.duty_cycle);
+}
+
+static DEVICE_ATTR_RW(period);
+static DEVICE_ATTR_RW(duty_cycle);
+static DEVICE_ATTR_RW(enable);
+static DEVICE_ATTR_RW(polarity);
+static DEVICE_ATTR_RO(capture);
+
+static struct attribute *pwm_attrs[] = {
+ &dev_attr_period.attr,
+ &dev_attr_duty_cycle.attr,
+ &dev_attr_enable.attr,
+ &dev_attr_polarity.attr,
+ &dev_attr_capture.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(pwm);
+
+static void pwm_export_release(struct device *pwm_dev)
+{
+ struct pwm_export *export = pwmexport_from_dev(pwm_dev);
+
+ kfree(export);
+}
+
+static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm)
+{
+ struct pwm_export *export;
+ char *pwm_prop[2];
+ int ret;
+
+ if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
+ return -EBUSY;
+
+ export = kzalloc(sizeof(*export), GFP_KERNEL);
+ if (!export) {
+ clear_bit(PWMF_EXPORTED, &pwm->flags);
+ return -ENOMEM;
+ }
+
+ export->pwm = pwm;
+ mutex_init(&export->lock);
+
+ export->pwm_dev.release = pwm_export_release;
+ export->pwm_dev.parent = pwmchip_dev;
+ export->pwm_dev.devt = MKDEV(0, 0);
+ export->pwm_dev.groups = pwm_groups;
+ dev_set_name(&export->pwm_dev, "pwm%u", pwm->hwpwm);
+
+ ret = device_register(&export->pwm_dev);
+ if (ret) {
+ clear_bit(PWMF_EXPORTED, &pwm->flags);
+ put_device(&export->pwm_dev);
+ export = NULL;
+ return ret;
+ }
+ pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm);
+ pwm_prop[1] = NULL;
+ kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
+ kfree(pwm_prop[0]);
+
+ return 0;
+}
+
+static int pwm_unexport_match(struct device *pwm_dev, void *data)
+{
+ return pwm_from_dev(pwm_dev) == data;
+}
+
+static int pwm_unexport_child(struct device *pwmchip_dev, struct pwm_device *pwm)
+{
+ struct device *pwm_dev;
+ char *pwm_prop[2];
+
+ if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
+ return -ENODEV;
+
+ pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
+ if (!pwm_dev)
+ return -ENODEV;
+
+ pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm);
+ pwm_prop[1] = NULL;
+ kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
+ kfree(pwm_prop[0]);
+
+ /* for device_find_child() */
+ put_device(pwm_dev);
+ device_unregister(pwm_dev);
+ pwm_put(pwm);
+
+ return 0;
+}
+
+static ssize_t export_store(struct device *pwmchip_dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+ struct pwm_device *pwm;
+ unsigned int hwpwm;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &hwpwm);
+ if (ret < 0)
+ return ret;
+
+ if (hwpwm >= chip->npwm)
+ return -ENODEV;
+
+ pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
+ if (IS_ERR(pwm))
+ return PTR_ERR(pwm);
+
+ ret = pwm_export_child(pwmchip_dev, pwm);
+ if (ret < 0)
+ pwm_put(pwm);
+
+ return ret ? : len;
+}
+static DEVICE_ATTR_WO(export);
+
+static ssize_t unexport_store(struct device *pwmchip_dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+ unsigned int hwpwm;
+ int ret;
+
+ ret = kstrtouint(buf, 0, &hwpwm);
+ if (ret < 0)
+ return ret;
+
+ if (hwpwm >= chip->npwm)
+ return -ENODEV;
+
+ ret = pwm_unexport_child(pwmchip_dev, &chip->pwms[hwpwm]);
+
+ return ret ? : len;
+}
+static DEVICE_ATTR_WO(unexport);
+
+static ssize_t npwm_show(struct device *pwmchip_dev, struct device_attribute *attr,
+ char *buf)
+{
+ const struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+
+ return sysfs_emit(buf, "%u\n", chip->npwm);
+}
+static DEVICE_ATTR_RO(npwm);
+
+static struct attribute *pwm_chip_attrs[] = {
+ &dev_attr_export.attr,
+ &dev_attr_unexport.attr,
+ &dev_attr_npwm.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(pwm_chip);
+
+/* takes export->lock on success */
+static struct pwm_export *pwm_class_get_state(struct device *pwmchip_dev,
+ struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct device *pwm_dev;
+ struct pwm_export *export;
+
+ if (!test_bit(PWMF_EXPORTED, &pwm->flags))
+ return NULL;
+
+ pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
+ if (!pwm_dev)
+ return NULL;
+
+ export = pwmexport_from_dev(pwm_dev);
+ put_device(pwm_dev); /* 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_might_sleep(pwm, state);
+
+ /* release lock taken in pwm_class_get_state */
+ mutex_unlock(&export->lock);
+
+ return ret;
+}
+
+static int pwm_class_resume_npwm(struct device *pwmchip_dev, unsigned int npwm)
+{
+ struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+ 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(pwmchip_dev, pwm, &state);
+ if (!export)
+ continue;
+
+ /* If pwmchip was not enabled before suspend, do nothing. */
+ if (!export->suspend.enabled) {
+ /* release lock taken in pwm_class_get_state */
+ mutex_unlock(&export->lock);
+ continue;
+ }
+
+ state.enabled = export->suspend.enabled;
+ ret = pwm_class_apply_state(export, pwm, &state);
+ if (ret < 0)
+ break;
+ }
+
+ return ret;
+}
+
+static int pwm_class_suspend(struct device *pwmchip_dev)
+{
+ struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+ 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(pwmchip_dev, pwm, &state);
+ if (!export)
+ continue;
+
+ /*
+ * If pwmchip was not enabled before suspend, save
+ * state for resume time and do nothing else.
+ */
+ export->suspend = state;
+ if (!state.enabled) {
+ /* release lock taken in pwm_class_get_state */
+ mutex_unlock(&export->lock);
+ continue;
+ }
+
+ 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(pwmchip_dev, i);
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int pwm_class_resume(struct device *pwmchip_dev)
+{
+ struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
+
+ return pwm_class_resume_npwm(pwmchip_dev, chip->npwm);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
+
+static struct class pwm_class = {
+ .name = "pwm",
+ .dev_groups = pwm_chip_groups,
+ .pm = pm_sleep_ptr(&pwm_class_pm_ops),
+};
+
+static int pwmchip_sysfs_match(struct device *pwmchip_dev, const void *data)
+{
+ return pwmchip_from_dev(pwmchip_dev) == data;
+}
+
+static void pwmchip_sysfs_export(struct pwm_chip *chip)
+{
+ struct device *pwmchip_dev;
+
+ /*
+ * If device_create() fails the pwm_chip is still usable by
+ * the kernel it's just not exported.
+ */
+ pwmchip_dev = device_create(&pwm_class, pwmchip_parent(chip), MKDEV(0, 0), chip,
+ "pwmchip%d", chip->id);
+ if (IS_ERR(pwmchip_dev)) {
+ dev_warn(pwmchip_parent(chip),
+ "device_create failed for pwm_chip sysfs export\n");
+ }
+}
+
+static void pwmchip_sysfs_unexport(struct pwm_chip *chip)
+{
+ struct device *pwmchip_dev;
+ unsigned int i;
+
+ pwmchip_dev = class_find_device(&pwm_class, NULL, chip,
+ pwmchip_sysfs_match);
+ if (!pwmchip_dev)
+ return;
+
+ for (i = 0; i < chip->npwm; i++) {
+ struct pwm_device *pwm = &chip->pwms[i];
+
+ if (test_bit(PWMF_EXPORTED, &pwm->flags))
+ pwm_unexport_child(pwmchip_dev, pwm);
+ }
+
+ put_device(pwmchip_dev);
+ device_unregister(pwmchip_dev);
+}
+
#define PWMCHIP_ALIGN ARCH_DMA_MINALIGN
static void *pwmchip_priv(struct pwm_chip *chip)
}
EXPORT_SYMBOL_GPL(devm_fwnode_pwm_get);
-#ifdef CONFIG_DEBUG_FS
static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s)
{
unsigned int i;
DEFINE_SEQ_ATTRIBUTE(pwm_debugfs);
-static int __init pwm_debugfs_init(void)
+static int __init pwm_init(void)
{
- debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
+ if (IS_ENABLED(CONFIG_DEBUG_FS))
+ debugfs_create_file("pwm", 0444, NULL, NULL, &pwm_debugfs_fops);
- return 0;
+ return class_register(&pwm_class);
}
-subsys_initcall(pwm_debugfs_init);
-#endif /* CONFIG_DEBUG_FS */
+subsys_initcall(pwm_init);
+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * A simple sysfs interface for the generic PWM framework
- *
- * Copyright (C) 2013 H Hartley Sweeten <hsweeten@visionengravers.com>
- *
- * Based on previous work by Lars Poeschel <poeschel@lemonage.de>
- */
-
-#include <linux/device.h>
-#include <linux/mutex.h>
-#include <linux/err.h>
-#include <linux/slab.h>
-#include <linux/kdev_t.h>
-#include <linux/pwm.h>
-
-struct pwm_export {
- struct device pwm_dev;
- struct pwm_device *pwm;
- struct mutex lock;
- struct pwm_state suspend;
-};
-
-static inline struct pwm_chip *pwmchip_from_dev(struct device *pwmchip_dev)
-{
- return dev_get_drvdata(pwmchip_dev);
-}
-
-static inline struct pwm_export *pwmexport_from_dev(struct device *pwm_dev)
-{
- return container_of(pwm_dev, struct pwm_export, pwm_dev);
-}
-
-static inline struct pwm_device *pwm_from_dev(struct device *pwm_dev)
-{
- struct pwm_export *export = pwmexport_from_dev(pwm_dev);
-
- return export->pwm;
-}
-
-static ssize_t period_show(struct device *pwm_dev,
- struct device_attribute *attr,
- char *buf)
-{
- const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
- struct pwm_state state;
-
- pwm_get_state(pwm, &state);
-
- return sysfs_emit(buf, "%llu\n", state.period);
-}
-
-static ssize_t period_store(struct device *pwm_dev,
- struct device_attribute *attr,
- const char *buf, size_t size)
-{
- struct pwm_export *export = pwmexport_from_dev(pwm_dev);
- struct pwm_device *pwm = export->pwm;
- struct pwm_state state;
- u64 val;
- int ret;
-
- ret = kstrtou64(buf, 0, &val);
- if (ret)
- return ret;
-
- mutex_lock(&export->lock);
- pwm_get_state(pwm, &state);
- state.period = val;
- ret = pwm_apply_might_sleep(pwm, &state);
- mutex_unlock(&export->lock);
-
- return ret ? : size;
-}
-
-static ssize_t duty_cycle_show(struct device *pwm_dev,
- struct device_attribute *attr,
- char *buf)
-{
- const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
- struct pwm_state state;
-
- pwm_get_state(pwm, &state);
-
- return sysfs_emit(buf, "%llu\n", state.duty_cycle);
-}
-
-static ssize_t duty_cycle_store(struct device *pwm_dev,
- struct device_attribute *attr,
- const char *buf, size_t size)
-{
- struct pwm_export *export = pwmexport_from_dev(pwm_dev);
- struct pwm_device *pwm = export->pwm;
- struct pwm_state state;
- u64 val;
- int ret;
-
- ret = kstrtou64(buf, 0, &val);
- if (ret)
- return ret;
-
- mutex_lock(&export->lock);
- pwm_get_state(pwm, &state);
- state.duty_cycle = val;
- ret = pwm_apply_might_sleep(pwm, &state);
- mutex_unlock(&export->lock);
-
- return ret ? : size;
-}
-
-static ssize_t enable_show(struct device *pwm_dev,
- struct device_attribute *attr,
- char *buf)
-{
- const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
- struct pwm_state state;
-
- pwm_get_state(pwm, &state);
-
- return sysfs_emit(buf, "%d\n", state.enabled);
-}
-
-static ssize_t enable_store(struct device *pwm_dev,
- struct device_attribute *attr,
- const char *buf, size_t size)
-{
- struct pwm_export *export = pwmexport_from_dev(pwm_dev);
- struct pwm_device *pwm = export->pwm;
- struct pwm_state state;
- int val, ret;
-
- ret = kstrtoint(buf, 0, &val);
- if (ret)
- return ret;
-
- mutex_lock(&export->lock);
-
- pwm_get_state(pwm, &state);
-
- switch (val) {
- case 0:
- state.enabled = false;
- break;
- case 1:
- state.enabled = true;
- break;
- default:
- ret = -EINVAL;
- goto unlock;
- }
-
- ret = pwm_apply_might_sleep(pwm, &state);
-
-unlock:
- mutex_unlock(&export->lock);
- return ret ? : size;
-}
-
-static ssize_t polarity_show(struct device *pwm_dev,
- struct device_attribute *attr,
- char *buf)
-{
- const struct pwm_device *pwm = pwm_from_dev(pwm_dev);
- const char *polarity = "unknown";
- struct pwm_state state;
-
- pwm_get_state(pwm, &state);
-
- switch (state.polarity) {
- case PWM_POLARITY_NORMAL:
- polarity = "normal";
- break;
-
- case PWM_POLARITY_INVERSED:
- polarity = "inversed";
- break;
- }
-
- return sysfs_emit(buf, "%s\n", polarity);
-}
-
-static ssize_t polarity_store(struct device *pwm_dev,
- struct device_attribute *attr,
- const char *buf, size_t size)
-{
- struct pwm_export *export = pwmexport_from_dev(pwm_dev);
- struct pwm_device *pwm = export->pwm;
- enum pwm_polarity polarity;
- struct pwm_state state;
- int ret;
-
- if (sysfs_streq(buf, "normal"))
- polarity = PWM_POLARITY_NORMAL;
- else if (sysfs_streq(buf, "inversed"))
- polarity = PWM_POLARITY_INVERSED;
- else
- return -EINVAL;
-
- mutex_lock(&export->lock);
- pwm_get_state(pwm, &state);
- state.polarity = polarity;
- ret = pwm_apply_might_sleep(pwm, &state);
- mutex_unlock(&export->lock);
-
- return ret ? : size;
-}
-
-static ssize_t capture_show(struct device *pwm_dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct pwm_device *pwm = pwm_from_dev(pwm_dev);
- struct pwm_capture result;
- int ret;
-
- ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ));
- if (ret)
- return ret;
-
- return sysfs_emit(buf, "%u %u\n", result.period, result.duty_cycle);
-}
-
-static DEVICE_ATTR_RW(period);
-static DEVICE_ATTR_RW(duty_cycle);
-static DEVICE_ATTR_RW(enable);
-static DEVICE_ATTR_RW(polarity);
-static DEVICE_ATTR_RO(capture);
-
-static struct attribute *pwm_attrs[] = {
- &dev_attr_period.attr,
- &dev_attr_duty_cycle.attr,
- &dev_attr_enable.attr,
- &dev_attr_polarity.attr,
- &dev_attr_capture.attr,
- NULL
-};
-ATTRIBUTE_GROUPS(pwm);
-
-static void pwm_export_release(struct device *pwm_dev)
-{
- struct pwm_export *export = pwmexport_from_dev(pwm_dev);
-
- kfree(export);
-}
-
-static int pwm_export_child(struct device *pwmchip_dev, struct pwm_device *pwm)
-{
- struct pwm_export *export;
- char *pwm_prop[2];
- int ret;
-
- if (test_and_set_bit(PWMF_EXPORTED, &pwm->flags))
- return -EBUSY;
-
- export = kzalloc(sizeof(*export), GFP_KERNEL);
- if (!export) {
- clear_bit(PWMF_EXPORTED, &pwm->flags);
- return -ENOMEM;
- }
-
- export->pwm = pwm;
- mutex_init(&export->lock);
-
- export->pwm_dev.release = pwm_export_release;
- export->pwm_dev.parent = pwmchip_dev;
- export->pwm_dev.devt = MKDEV(0, 0);
- export->pwm_dev.groups = pwm_groups;
- dev_set_name(&export->pwm_dev, "pwm%u", pwm->hwpwm);
-
- ret = device_register(&export->pwm_dev);
- if (ret) {
- clear_bit(PWMF_EXPORTED, &pwm->flags);
- put_device(&export->pwm_dev);
- export = NULL;
- return ret;
- }
- pwm_prop[0] = kasprintf(GFP_KERNEL, "EXPORT=pwm%u", pwm->hwpwm);
- pwm_prop[1] = NULL;
- kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
- kfree(pwm_prop[0]);
-
- return 0;
-}
-
-static int pwm_unexport_match(struct device *pwm_dev, void *data)
-{
- return pwm_from_dev(pwm_dev) == data;
-}
-
-static int pwm_unexport_child(struct device *pwmchip_dev, struct pwm_device *pwm)
-{
- struct device *pwm_dev;
- char *pwm_prop[2];
-
- if (!test_and_clear_bit(PWMF_EXPORTED, &pwm->flags))
- return -ENODEV;
-
- pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
- if (!pwm_dev)
- return -ENODEV;
-
- pwm_prop[0] = kasprintf(GFP_KERNEL, "UNEXPORT=pwm%u", pwm->hwpwm);
- pwm_prop[1] = NULL;
- kobject_uevent_env(&pwmchip_dev->kobj, KOBJ_CHANGE, pwm_prop);
- kfree(pwm_prop[0]);
-
- /* for device_find_child() */
- put_device(pwm_dev);
- device_unregister(pwm_dev);
- pwm_put(pwm);
-
- return 0;
-}
-
-static ssize_t export_store(struct device *pwmchip_dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
- struct pwm_device *pwm;
- unsigned int hwpwm;
- int ret;
-
- ret = kstrtouint(buf, 0, &hwpwm);
- if (ret < 0)
- return ret;
-
- if (hwpwm >= chip->npwm)
- return -ENODEV;
-
- pwm = pwm_request_from_chip(chip, hwpwm, "sysfs");
- if (IS_ERR(pwm))
- return PTR_ERR(pwm);
-
- ret = pwm_export_child(pwmchip_dev, pwm);
- if (ret < 0)
- pwm_put(pwm);
-
- return ret ? : len;
-}
-static DEVICE_ATTR_WO(export);
-
-static ssize_t unexport_store(struct device *pwmchip_dev,
- struct device_attribute *attr,
- const char *buf, size_t len)
-{
- struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
- unsigned int hwpwm;
- int ret;
-
- ret = kstrtouint(buf, 0, &hwpwm);
- if (ret < 0)
- return ret;
-
- if (hwpwm >= chip->npwm)
- return -ENODEV;
-
- ret = pwm_unexport_child(pwmchip_dev, &chip->pwms[hwpwm]);
-
- return ret ? : len;
-}
-static DEVICE_ATTR_WO(unexport);
-
-static ssize_t npwm_show(struct device *pwmchip_dev, struct device_attribute *attr,
- char *buf)
-{
- const struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
-
- return sysfs_emit(buf, "%u\n", chip->npwm);
-}
-static DEVICE_ATTR_RO(npwm);
-
-static struct attribute *pwm_chip_attrs[] = {
- &dev_attr_export.attr,
- &dev_attr_unexport.attr,
- &dev_attr_npwm.attr,
- NULL,
-};
-ATTRIBUTE_GROUPS(pwm_chip);
-
-/* takes export->lock on success */
-static struct pwm_export *pwm_class_get_state(struct device *pwmchip_dev,
- struct pwm_device *pwm,
- struct pwm_state *state)
-{
- struct device *pwm_dev;
- struct pwm_export *export;
-
- if (!test_bit(PWMF_EXPORTED, &pwm->flags))
- return NULL;
-
- pwm_dev = device_find_child(pwmchip_dev, pwm, pwm_unexport_match);
- if (!pwm_dev)
- return NULL;
-
- export = pwmexport_from_dev(pwm_dev);
- put_device(pwm_dev); /* 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_might_sleep(pwm, state);
-
- /* release lock taken in pwm_class_get_state */
- mutex_unlock(&export->lock);
-
- return ret;
-}
-
-static int pwm_class_resume_npwm(struct device *pwmchip_dev, unsigned int npwm)
-{
- struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
- 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(pwmchip_dev, pwm, &state);
- if (!export)
- continue;
-
- /* If pwmchip was not enabled before suspend, do nothing. */
- if (!export->suspend.enabled) {
- /* release lock taken in pwm_class_get_state */
- mutex_unlock(&export->lock);
- continue;
- }
-
- state.enabled = export->suspend.enabled;
- ret = pwm_class_apply_state(export, pwm, &state);
- if (ret < 0)
- break;
- }
-
- return ret;
-}
-
-static int pwm_class_suspend(struct device *pwmchip_dev)
-{
- struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
- 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(pwmchip_dev, pwm, &state);
- if (!export)
- continue;
-
- /*
- * If pwmchip was not enabled before suspend, save
- * state for resume time and do nothing else.
- */
- export->suspend = state;
- if (!state.enabled) {
- /* release lock taken in pwm_class_get_state */
- mutex_unlock(&export->lock);
- continue;
- }
-
- 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(pwmchip_dev, i);
- break;
- }
- }
-
- return ret;
-}
-
-static int pwm_class_resume(struct device *pwmchip_dev)
-{
- struct pwm_chip *chip = pwmchip_from_dev(pwmchip_dev);
-
- return pwm_class_resume_npwm(pwmchip_dev, chip->npwm);
-}
-
-static DEFINE_SIMPLE_DEV_PM_OPS(pwm_class_pm_ops, pwm_class_suspend, pwm_class_resume);
-
-static struct class pwm_class = {
- .name = "pwm",
- .dev_groups = pwm_chip_groups,
- .pm = pm_sleep_ptr(&pwm_class_pm_ops),
-};
-
-static int pwmchip_sysfs_match(struct device *pwmchip_dev, const void *data)
-{
- return pwmchip_from_dev(pwmchip_dev) == data;
-}
-
-void pwmchip_sysfs_export(struct pwm_chip *chip)
-{
- struct device *pwmchip_dev;
-
- /*
- * If device_create() fails the pwm_chip is still usable by
- * the kernel it's just not exported.
- */
- pwmchip_dev = device_create(&pwm_class, pwmchip_parent(chip), MKDEV(0, 0), chip,
- "pwmchip%d", chip->id);
- if (IS_ERR(pwmchip_dev)) {
- dev_warn(pwmchip_parent(chip),
- "device_create failed for pwm_chip sysfs export\n");
- }
-}
-
-void pwmchip_sysfs_unexport(struct pwm_chip *chip)
-{
- struct device *pwmchip_dev;
- unsigned int i;
-
- pwmchip_dev = class_find_device(&pwm_class, NULL, chip,
- pwmchip_sysfs_match);
- if (!pwmchip_dev)
- return;
-
- for (i = 0; i < chip->npwm; i++) {
- struct pwm_device *pwm = &chip->pwms[i];
-
- if (test_bit(PWMF_EXPORTED, &pwm->flags))
- pwm_unexport_child(pwmchip_dev, pwm);
- }
-
- put_device(pwmchip_dev);
- device_unregister(pwmchip_dev);
-}
-
-static int __init pwm_sysfs_init(void)
-{
- return class_register(&pwm_class);
-}
-subsys_initcall(pwm_sysfs_init);
}
#endif
-#ifdef CONFIG_PWM_SYSFS
-void pwmchip_sysfs_export(struct pwm_chip *chip);
-void pwmchip_sysfs_unexport(struct pwm_chip *chip);
-#else
-static inline void pwmchip_sysfs_export(struct pwm_chip *chip)
-{
-}
-
-static inline void pwmchip_sysfs_unexport(struct pwm_chip *chip)
-{
-}
-#endif /* CONFIG_PWM_SYSFS */
-
#endif /* __LINUX_PWM_H */
projects / linux-block.git / commitdiff