From e9cc807f87ffd1ccc919731e8f624982935af3e0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Sun, 17 Mar 2024 11:40:34 +0100 Subject: pwm: Move contents of sysfs.c into core.c MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit With the upcoming restructuring having all in a single file simplifies things a bit. The relevant and somewhat visible changes are: - Some dropped prototypes from include/linux/pwm.h that were only necessary that core.c has a declaration of the symbols defined in sysfs.c. The respective functions are static now. - The pwm class now also exists if CONFIG_SYSFS isn't enabled. Having CONFIG_SYSFS is not very relevant today, but even without it the class and device stuff still provides lifetime tracking. - Both files had an initcall, these are merged into a single one now. Instead of a big #ifdef block for CONFIG_DEBUG_FS, a single if (IS_ENABLED(CONFIG_DEBUG_FS)) is used now. This increases compile coverage a bit and is a tad nicer on the eyes. Link: https://lore.kernel.org/r/9e2d39a5280d7dda5bfc6682a8aef510148635b2.1710670958.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König --- drivers/pwm/Kconfig | 4 - drivers/pwm/Makefile | 1 - drivers/pwm/core.c | 540 +++++++++++++++++++++++++++++++++++++++++++++++++- drivers/pwm/sysfs.c | 550 --------------------------------------------------- include/linux/pwm.h | 13 -- 5 files changed, 534 insertions(+), 574 deletions(-) delete mode 100644 drivers/pwm/sysfs.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 4b956d661755..1dd7921194f5 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -29,10 +29,6 @@ menuconfig PWM 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 diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index c5ec9e168ee7..90913519f11a 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -1,6 +1,5 @@ # 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 diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index d3f475eca97f..faa0f885e057 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -454,6 +454,535 @@ of_pwm_single_xlate(struct pwm_chip *chip, const struct of_phandle_args *args) } 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) @@ -1086,7 +1615,6 @@ struct pwm_device *devm_fwnode_pwm_get(struct device *dev, } 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; @@ -1171,11 +1699,11 @@ static const struct seq_operations pwm_debugfs_sops = { 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); diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c deleted file mode 100644 index 1a1b1f6dd98f..000000000000 --- a/drivers/pwm/sysfs.c +++ /dev/null @@ -1,550 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * A simple sysfs interface for the generic PWM framework - * - * Copyright (C) 2013 H Hartley Sweeten - * - * Based on previous work by Lars Poeschel - */ - -#include -#include -#include -#include -#include -#include - -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); diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 94a642a88817..17e45d8413ed 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -630,17 +630,4 @@ static inline void pwm_remove_table(struct pwm_lookup *table, size_t num) } #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 */ -- cgit v1.2.3