| /* |
| * Generic pwmlib implementation |
| * |
| * Copyright (C) 2011 Sascha Hauer <s.hauer@pengutronix.de> |
| * Copyright (C) 2011-2012 Avionic Design GmbH |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2, or (at your option) |
| * any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; see the file COPYING. If not, write to |
| * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/pwm.h> |
| #include <linux/radix-tree.h> |
| #include <linux/list.h> |
| #include <linux/mutex.h> |
| #include <linux/err.h> |
| #include <linux/slab.h> |
| #include <linux/device.h> |
| #include <linux/debugfs.h> |
| #include <linux/seq_file.h> |
| |
| #define MAX_PWMS 1024 |
| |
| /* flags in the third cell of the DT PWM specifier */ |
| #define PWM_SPEC_POLARITY (1 << 0) |
| |
| static DEFINE_MUTEX(pwm_lookup_lock); |
| static LIST_HEAD(pwm_lookup_list); |
| static DEFINE_MUTEX(pwm_lock); |
| static LIST_HEAD(pwm_chips); |
| static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); |
| static RADIX_TREE(pwm_tree, GFP_KERNEL); |
| |
| static struct pwm_device *pwm_to_device(unsigned int pwm) |
| { |
| return radix_tree_lookup(&pwm_tree, pwm); |
| } |
| |
| static int alloc_pwms(int pwm, unsigned int count) |
| { |
| unsigned int from = 0; |
| unsigned int start; |
| |
| if (pwm >= MAX_PWMS) |
| return -EINVAL; |
| |
| if (pwm >= 0) |
| from = pwm; |
| |
| start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
| count, 0); |
| |
| if (pwm >= 0 && start != pwm) |
| return -EEXIST; |
| |
| if (start + count > MAX_PWMS) |
| return -ENOSPC; |
| |
| return start; |
| } |
| |
| static void free_pwms(struct pwm_chip *chip) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < chip->npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| radix_tree_delete(&pwm_tree, pwm->pwm); |
| } |
| |
| bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
| |
| kfree(chip->pwms); |
| chip->pwms = NULL; |
| } |
| |
| static struct pwm_chip *pwmchip_find_by_name(const char *name) |
| { |
| struct pwm_chip *chip; |
| |
| if (!name) |
| return NULL; |
| |
| mutex_lock(&pwm_lock); |
| |
| list_for_each_entry(chip, &pwm_chips, list) { |
| const char *chip_name = dev_name(chip->dev); |
| |
| if (chip_name && strcmp(chip_name, name) == 0) { |
| mutex_unlock(&pwm_lock); |
| return chip; |
| } |
| } |
| |
| mutex_unlock(&pwm_lock); |
| |
| return NULL; |
| } |
| |
| static int pwm_device_request(struct pwm_device *pwm, const char *label) |
| { |
| int err; |
| |
| if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| return -EBUSY; |
| |
| if (!try_module_get(pwm->chip->ops->owner)) |
| return -ENODEV; |
| |
| if (pwm->chip->ops->request) { |
| err = pwm->chip->ops->request(pwm->chip, pwm); |
| if (err) { |
| module_put(pwm->chip->ops->owner); |
| return err; |
| } |
| } |
| |
| set_bit(PWMF_REQUESTED, &pwm->flags); |
| pwm->label = label; |
| |
| return 0; |
| } |
| |
| struct pwm_device * |
| of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) |
| { |
| struct pwm_device *pwm; |
| |
| if (pc->of_pwm_n_cells < 3) |
| return ERR_PTR(-EINVAL); |
| |
| if (args->args[0] >= pc->npwm) |
| return ERR_PTR(-EINVAL); |
| |
| pwm = pwm_request_from_chip(pc, args->args[0], NULL); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| pwm_set_period(pwm, args->args[1]); |
| |
| if (args->args[2] & PWM_SPEC_POLARITY) |
| pwm_set_polarity(pwm, PWM_POLARITY_INVERSED); |
| else |
| pwm_set_polarity(pwm, PWM_POLARITY_NORMAL); |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); |
| |
| static struct pwm_device * |
| of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) |
| { |
| struct pwm_device *pwm; |
| |
| if (pc->of_pwm_n_cells < 2) |
| return ERR_PTR(-EINVAL); |
| |
| if (args->args[0] >= pc->npwm) |
| return ERR_PTR(-EINVAL); |
| |
| pwm = pwm_request_from_chip(pc, args->args[0], NULL); |
| if (IS_ERR(pwm)) |
| return pwm; |
| |
| pwm_set_period(pwm, args->args[1]); |
| |
| return pwm; |
| } |
| |
| static void of_pwmchip_add(struct pwm_chip *chip) |
| { |
| if (!chip->dev || !chip->dev->of_node) |
| return; |
| |
| if (!chip->of_xlate) { |
| chip->of_xlate = of_pwm_simple_xlate; |
| chip->of_pwm_n_cells = 2; |
| } |
| |
| of_node_get(chip->dev->of_node); |
| } |
| |
| static void of_pwmchip_remove(struct pwm_chip *chip) |
| { |
| if (chip->dev && chip->dev->of_node) |
| of_node_put(chip->dev->of_node); |
| } |
| |
| /** |
| * pwm_set_chip_data() - set private chip data for a PWM |
| * @pwm: PWM device |
| * @data: pointer to chip-specific data |
| */ |
| int pwm_set_chip_data(struct pwm_device *pwm, void *data) |
| { |
| if (!pwm) |
| return -EINVAL; |
| |
| pwm->chip_data = data; |
| |
| return 0; |
| } |
| |
| /** |
| * pwm_get_chip_data() - get private chip data for a PWM |
| * @pwm: PWM device |
| */ |
| void *pwm_get_chip_data(struct pwm_device *pwm) |
| { |
| return pwm ? pwm->chip_data : NULL; |
| } |
| |
| /** |
| * pwmchip_add() - register a new PWM chip |
| * @chip: the PWM chip to add |
| * |
| * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base |
| * will be used. |
| */ |
| int pwmchip_add(struct pwm_chip *chip) |
| { |
| struct pwm_device *pwm; |
| unsigned int i; |
| int ret; |
| |
| if (!chip || !chip->dev || !chip->ops || !chip->ops->config || |
| !chip->ops->enable || !chip->ops->disable) |
| return -EINVAL; |
| |
| mutex_lock(&pwm_lock); |
| |
| ret = alloc_pwms(chip->base, chip->npwm); |
| if (ret < 0) |
| goto out; |
| |
| chip->pwms = kzalloc(chip->npwm * sizeof(*pwm), GFP_KERNEL); |
| if (!chip->pwms) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| chip->base = ret; |
| |
| for (i = 0; i < chip->npwm; i++) { |
| pwm = &chip->pwms[i]; |
| |
| pwm->chip = chip; |
| pwm->pwm = chip->base + i; |
| pwm->hwpwm = i; |
| |
| radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
| } |
| |
| bitmap_set(allocated_pwms, chip->base, chip->npwm); |
| |
| INIT_LIST_HEAD(&chip->list); |
| list_add(&chip->list, &pwm_chips); |
| |
| ret = 0; |
| |
| if (IS_ENABLED(CONFIG_OF)) |
| of_pwmchip_add(chip); |
| |
| out: |
| mutex_unlock(&pwm_lock); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(pwmchip_add); |
| |
| /** |
| * pwmchip_remove() - remove a PWM chip |
| * @chip: the PWM chip to remove |
| * |
| * Removes a PWM chip. This function may return busy if the PWM chip provides |
| * a PWM device that is still requested. |
| */ |
| int pwmchip_remove(struct pwm_chip *chip) |
| { |
| unsigned int i; |
| int ret = 0; |
| |
| mutex_lock(&pwm_lock); |
| |
| for (i = 0; i < chip->npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| |
| if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
| ret = -EBUSY; |
| goto out; |
| } |
| } |
| |
| list_del_init(&chip->list); |
| |
| if (IS_ENABLED(CONFIG_OF)) |
| of_pwmchip_remove(chip); |
| |
| free_pwms(chip); |
| |
| out: |
| mutex_unlock(&pwm_lock); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(pwmchip_remove); |
| |
| /** |
| * pwm_request() - request a PWM device |
| * @pwm_id: global PWM device index |
| * @label: PWM device label |
| * |
| * This function is deprecated, use pwm_get() instead. |
| */ |
| struct pwm_device *pwm_request(int pwm, const char *label) |
| { |
| struct pwm_device *dev; |
| int err; |
| |
| if (pwm < 0 || pwm >= MAX_PWMS) |
| return ERR_PTR(-EINVAL); |
| |
| mutex_lock(&pwm_lock); |
| |
| dev = pwm_to_device(pwm); |
| if (!dev) { |
| dev = ERR_PTR(-EPROBE_DEFER); |
| goto out; |
| } |
| |
| err = pwm_device_request(dev, label); |
| if (err < 0) |
| dev = ERR_PTR(err); |
| |
| out: |
| mutex_unlock(&pwm_lock); |
| |
| return dev; |
| } |
| EXPORT_SYMBOL_GPL(pwm_request); |
| |
| /** |
| * pwm_request_from_chip() - request a PWM device relative to a PWM chip |
| * @chip: PWM chip |
| * @index: per-chip index of the PWM to request |
| * @label: a literal description string of this PWM |
| * |
| * Returns the PWM at the given index of the given PWM chip. A negative error |
| * code is returned if the index is not valid for the specified PWM chip or |
| * if the PWM device cannot be requested. |
| */ |
| struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, |
| unsigned int index, |
| const char *label) |
| { |
| struct pwm_device *pwm; |
| int err; |
| |
| if (!chip || index >= chip->npwm) |
| return ERR_PTR(-EINVAL); |
| |
| mutex_lock(&pwm_lock); |
| pwm = &chip->pwms[index]; |
| |
| err = pwm_device_request(pwm, label); |
| if (err < 0) |
| pwm = ERR_PTR(err); |
| |
| mutex_unlock(&pwm_lock); |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
| |
| /** |
| * pwm_free() - free a PWM device |
| * @pwm: PWM device |
| * |
| * This function is deprecated, use pwm_put() instead. |
| */ |
| void pwm_free(struct pwm_device *pwm) |
| { |
| pwm_put(pwm); |
| } |
| EXPORT_SYMBOL_GPL(pwm_free); |
| |
| /** |
| * pwm_config() - change a PWM device configuration |
| * @pwm: PWM device |
| * @duty_ns: "on" time (in nanoseconds) |
| * @period_ns: duration (in nanoseconds) of one cycle |
| */ |
| int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) |
| { |
| if (!pwm || duty_ns < 0 || period_ns <= 0 || duty_ns > period_ns) |
| return -EINVAL; |
| |
| return pwm->chip->ops->config(pwm->chip, pwm, duty_ns, period_ns); |
| } |
| EXPORT_SYMBOL_GPL(pwm_config); |
| |
| /** |
| * pwm_set_polarity() - configure the polarity of a PWM signal |
| * @pwm: PWM device |
| * @polarity: new polarity of the PWM signal |
| * |
| * Note that the polarity cannot be configured while the PWM device is enabled |
| */ |
| int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity) |
| { |
| if (!pwm || !pwm->chip->ops) |
| return -EINVAL; |
| |
| if (!pwm->chip->ops->set_polarity) |
| return -ENOSYS; |
| |
| if (test_bit(PWMF_ENABLED, &pwm->flags)) |
| return -EBUSY; |
| |
| return pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity); |
| } |
| EXPORT_SYMBOL_GPL(pwm_set_polarity); |
| |
| /** |
| * pwm_enable() - start a PWM output toggling |
| * @pwm: PWM device |
| */ |
| int pwm_enable(struct pwm_device *pwm) |
| { |
| if (pwm && !test_and_set_bit(PWMF_ENABLED, &pwm->flags)) |
| return pwm->chip->ops->enable(pwm->chip, pwm); |
| |
| return pwm ? 0 : -EINVAL; |
| } |
| EXPORT_SYMBOL_GPL(pwm_enable); |
| |
| /** |
| * pwm_disable() - stop a PWM output toggling |
| * @pwm: PWM device |
| */ |
| void pwm_disable(struct pwm_device *pwm) |
| { |
| if (pwm && test_and_clear_bit(PWMF_ENABLED, &pwm->flags)) |
| pwm->chip->ops->disable(pwm->chip, pwm); |
| } |
| EXPORT_SYMBOL_GPL(pwm_disable); |
| |
| static struct pwm_chip *of_node_to_pwmchip(struct device_node *np) |
| { |
| struct pwm_chip *chip; |
| |
| mutex_lock(&pwm_lock); |
| |
| list_for_each_entry(chip, &pwm_chips, list) |
| if (chip->dev && chip->dev->of_node == np) { |
| mutex_unlock(&pwm_lock); |
| return chip; |
| } |
| |
| mutex_unlock(&pwm_lock); |
| |
| return ERR_PTR(-EPROBE_DEFER); |
| } |
| |
| /** |
| * of_pwm_request() - request a PWM via the PWM framework |
| * @np: device node to get the PWM from |
| * @con_id: consumer name |
| * |
| * Returns the PWM device parsed from the phandle and index specified in the |
| * "pwms" property of a device tree node or a negative error-code on failure. |
| * Values parsed from the device tree are stored in the returned PWM device |
| * object. |
| * |
| * If con_id is NULL, the first PWM device listed in the "pwms" property will |
| * be requested. Otherwise the "pwm-names" property is used to do a reverse |
| * lookup of the PWM index. This also means that the "pwm-names" property |
| * becomes mandatory for devices that look up the PWM device via the con_id |
| * parameter. |
| */ |
| static struct pwm_device *of_pwm_request(struct device_node *np, |
| const char *con_id) |
| { |
| struct pwm_device *pwm = NULL; |
| struct of_phandle_args args; |
| struct pwm_chip *pc; |
| int index = 0; |
| int err; |
| |
| if (con_id) { |
| index = of_property_match_string(np, "pwm-names", con_id); |
| if (index < 0) |
| return ERR_PTR(index); |
| } |
| |
| err = of_parse_phandle_with_args(np, "pwms", "#pwm-cells", index, |
| &args); |
| if (err) { |
| pr_debug("%s(): can't parse \"pwms\" property\n", __func__); |
| return ERR_PTR(err); |
| } |
| |
| pc = of_node_to_pwmchip(args.np); |
| if (IS_ERR(pc)) { |
| pr_debug("%s(): PWM chip not found\n", __func__); |
| pwm = ERR_CAST(pc); |
| goto put; |
| } |
| |
| if (args.args_count != pc->of_pwm_n_cells) { |
| pr_debug("%s: wrong #pwm-cells for %s\n", np->full_name, |
| args.np->full_name); |
| pwm = ERR_PTR(-EINVAL); |
| goto put; |
| } |
| |
| pwm = pc->of_xlate(pc, &args); |
| if (IS_ERR(pwm)) |
| goto put; |
| |
| /* |
| * If a consumer name was not given, try to look it up from the |
| * "pwm-names" property if it exists. Otherwise use the name of |
| * the user device node. |
| */ |
| if (!con_id) { |
| err = of_property_read_string_index(np, "pwm-names", index, |
| &con_id); |
| if (err < 0) |
| con_id = np->name; |
| } |
| |
| pwm->label = con_id; |
| |
| put: |
| of_node_put(args.np); |
| |
| return pwm; |
| } |
| |
| /** |
| * pwm_add_table() - register PWM device consumers |
| * @table: array of consumers to register |
| * @num: number of consumers in table |
| */ |
| void __init pwm_add_table(struct pwm_lookup *table, size_t num) |
| { |
| mutex_lock(&pwm_lookup_lock); |
| |
| while (num--) { |
| list_add_tail(&table->list, &pwm_lookup_list); |
| table++; |
| } |
| |
| mutex_unlock(&pwm_lookup_lock); |
| } |
| |
| /** |
| * pwm_get() - look up and request a PWM device |
| * @dev: device for PWM consumer |
| * @con_id: consumer name |
| * |
| * Lookup is first attempted using DT. If the device was not instantiated from |
| * a device tree, a PWM chip and a relative index is looked up via a table |
| * supplied by board setup code (see pwm_add_table()). |
| * |
| * Once a PWM chip has been found the specified PWM device will be requested |
| * and is ready to be used. |
| */ |
| struct pwm_device *pwm_get(struct device *dev, const char *con_id) |
| { |
| struct pwm_device *pwm = ERR_PTR(-EPROBE_DEFER); |
| const char *dev_id = dev ? dev_name(dev) : NULL; |
| struct pwm_chip *chip = NULL; |
| unsigned int index = 0; |
| unsigned int best = 0; |
| struct pwm_lookup *p; |
| unsigned int match; |
| |
| /* look up via DT first */ |
| if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) |
| return of_pwm_request(dev->of_node, con_id); |
| |
| /* |
| * We look up the provider in the static table typically provided by |
| * board setup code. We first try to lookup the consumer device by |
| * name. If the consumer device was passed in as NULL or if no match |
| * was found, we try to find the consumer by directly looking it up |
| * by name. |
| * |
| * If a match is found, the provider PWM chip is looked up by name |
| * and a PWM device is requested using the PWM device per-chip index. |
| * |
| * The lookup algorithm was shamelessly taken from the clock |
| * framework: |
| * |
| * We do slightly fuzzy matching here: |
| * An entry with a NULL ID is assumed to be a wildcard. |
| * If an entry has a device ID, it must match |
| * If an entry has a connection ID, it must match |
| * Then we take the most specific entry - with the following order |
| * of precedence: dev+con > dev only > con only. |
| */ |
| mutex_lock(&pwm_lookup_lock); |
| |
| list_for_each_entry(p, &pwm_lookup_list, list) { |
| match = 0; |
| |
| if (p->dev_id) { |
| if (!dev_id || strcmp(p->dev_id, dev_id)) |
| continue; |
| |
| match += 2; |
| } |
| |
| if (p->con_id) { |
| if (!con_id || strcmp(p->con_id, con_id)) |
| continue; |
| |
| match += 1; |
| } |
| |
| if (match > best) { |
| chip = pwmchip_find_by_name(p->provider); |
| index = p->index; |
| |
| if (match != 3) |
| best = match; |
| else |
| break; |
| } |
| } |
| |
| if (chip) |
| pwm = pwm_request_from_chip(chip, index, con_id ?: dev_id); |
| |
| mutex_unlock(&pwm_lookup_lock); |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(pwm_get); |
| |
| /** |
| * pwm_put() - release a PWM device |
| * @pwm: PWM device |
| */ |
| void pwm_put(struct pwm_device *pwm) |
| { |
| if (!pwm) |
| return; |
| |
| mutex_lock(&pwm_lock); |
| |
| if (!test_and_clear_bit(PWMF_REQUESTED, &pwm->flags)) { |
| pr_warn("PWM device already freed\n"); |
| goto out; |
| } |
| |
| if (pwm->chip->ops->free) |
| pwm->chip->ops->free(pwm->chip, pwm); |
| |
| pwm->label = NULL; |
| |
| module_put(pwm->chip->ops->owner); |
| out: |
| mutex_unlock(&pwm_lock); |
| } |
| EXPORT_SYMBOL_GPL(pwm_put); |
| |
| static void devm_pwm_release(struct device *dev, void *res) |
| { |
| pwm_put(*(struct pwm_device **)res); |
| } |
| |
| /** |
| * devm_pwm_get() - resource managed pwm_get() |
| * @dev: device for PWM consumer |
| * @con_id: consumer name |
| * |
| * This function performs like pwm_get() but the acquired PWM device will |
| * automatically be released on driver detach. |
| */ |
| struct pwm_device *devm_pwm_get(struct device *dev, const char *con_id) |
| { |
| struct pwm_device **ptr, *pwm; |
| |
| ptr = devres_alloc(devm_pwm_release, sizeof(**ptr), GFP_KERNEL); |
| if (!ptr) |
| return ERR_PTR(-ENOMEM); |
| |
| pwm = pwm_get(dev, con_id); |
| if (!IS_ERR(pwm)) { |
| *ptr = pwm; |
| devres_add(dev, ptr); |
| } else { |
| devres_free(ptr); |
| } |
| |
| return pwm; |
| } |
| EXPORT_SYMBOL_GPL(devm_pwm_get); |
| |
| static int devm_pwm_match(struct device *dev, void *res, void *data) |
| { |
| struct pwm_device **p = res; |
| |
| if (WARN_ON(!p || !*p)) |
| return 0; |
| |
| return *p == data; |
| } |
| |
| /** |
| * devm_pwm_put() - resource managed pwm_put() |
| * @dev: device for PWM consumer |
| * @pwm: PWM device |
| * |
| * Release a PWM previously allocated using devm_pwm_get(). Calling this |
| * function is usually not needed because devm-allocated resources are |
| * automatically released on driver detach. |
| */ |
| void devm_pwm_put(struct device *dev, struct pwm_device *pwm) |
| { |
| WARN_ON(devres_release(dev, devm_pwm_release, devm_pwm_match, pwm)); |
| } |
| EXPORT_SYMBOL_GPL(devm_pwm_put); |
| |
| /** |
| * pwm_can_sleep() - report whether PWM access will sleep |
| * @pwm: PWM device |
| * |
| * It returns true if accessing the PWM can sleep, false otherwise. |
| */ |
| bool pwm_can_sleep(struct pwm_device *pwm) |
| { |
| return pwm->chip->can_sleep; |
| } |
| EXPORT_SYMBOL_GPL(pwm_can_sleep); |
| |
| #ifdef CONFIG_DEBUG_FS |
| static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) |
| { |
| unsigned int i; |
| |
| for (i = 0; i < chip->npwm; i++) { |
| struct pwm_device *pwm = &chip->pwms[i]; |
| |
| seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); |
| |
| if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
| seq_printf(s, " requested"); |
| |
| if (test_bit(PWMF_ENABLED, &pwm->flags)) |
| seq_printf(s, " enabled"); |
| |
| seq_printf(s, "\n"); |
| } |
| } |
| |
| static void *pwm_seq_start(struct seq_file *s, loff_t *pos) |
| { |
| mutex_lock(&pwm_lock); |
| s->private = ""; |
| |
| return seq_list_start(&pwm_chips, *pos); |
| } |
| |
| static void *pwm_seq_next(struct seq_file *s, void *v, loff_t *pos) |
| { |
| s->private = "\n"; |
| |
| return seq_list_next(v, &pwm_chips, pos); |
| } |
| |
| static void pwm_seq_stop(struct seq_file *s, void *v) |
| { |
| mutex_unlock(&pwm_lock); |
| } |
| |
| static int pwm_seq_show(struct seq_file *s, void *v) |
| { |
| struct pwm_chip *chip = list_entry(v, struct pwm_chip, list); |
| |
| seq_printf(s, "%s%s/%s, %d PWM device%s\n", (char *)s->private, |
| chip->dev->bus ? chip->dev->bus->name : "no-bus", |
| dev_name(chip->dev), chip->npwm, |
| (chip->npwm != 1) ? "s" : ""); |
| |
| if (chip->ops->dbg_show) |
| chip->ops->dbg_show(chip, s); |
| else |
| pwm_dbg_show(chip, s); |
| |
| return 0; |
| } |
| |
| static const struct seq_operations pwm_seq_ops = { |
| .start = pwm_seq_start, |
| .next = pwm_seq_next, |
| .stop = pwm_seq_stop, |
| .show = pwm_seq_show, |
| }; |
| |
| static int pwm_seq_open(struct inode *inode, struct file *file) |
| { |
| return seq_open(file, &pwm_seq_ops); |
| } |
| |
| static const struct file_operations pwm_debugfs_ops = { |
| .owner = THIS_MODULE, |
| .open = pwm_seq_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release, |
| }; |
| |
| static int __init pwm_debugfs_init(void) |
| { |
| debugfs_create_file("pwm", S_IFREG | S_IRUGO, NULL, NULL, |
| &pwm_debugfs_ops); |
| |
| return 0; |
| } |
| |
| subsys_initcall(pwm_debugfs_init); |
| #endif /* CONFIG_DEBUG_FS */ |