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1347 lines
31 KiB
1347 lines
31 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Generic pwmlib implementation |
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* |
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* Copyright (C) 2011 Sascha Hauer <[email protected]> |
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* Copyright (C) 2011-2012 Avionic Design GmbH |
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*/ |
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|
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#include <linux/acpi.h> |
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#include <linux/module.h> |
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#include <linux/pwm.h> |
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#include <linux/radix-tree.h> |
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#include <linux/list.h> |
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#include <linux/mutex.h> |
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#include <linux/err.h> |
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#include <linux/slab.h> |
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#include <linux/device.h> |
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#include <linux/debugfs.h> |
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#include <linux/seq_file.h> |
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#include <dt-bindings/pwm/pwm.h> |
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#define CREATE_TRACE_POINTS |
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#include <trace/events/pwm.h> |
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#define MAX_PWMS 1024 |
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static DEFINE_MUTEX(pwm_lookup_lock); |
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static LIST_HEAD(pwm_lookup_list); |
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static DEFINE_MUTEX(pwm_lock); |
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static LIST_HEAD(pwm_chips); |
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static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); |
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static RADIX_TREE(pwm_tree, GFP_KERNEL); |
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|
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static struct pwm_device *pwm_to_device(unsigned int pwm) |
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{ |
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return radix_tree_lookup(&pwm_tree, pwm); |
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} |
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|
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static int alloc_pwms(int pwm, unsigned int count) |
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{ |
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unsigned int from = 0; |
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unsigned int start; |
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|
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if (pwm >= MAX_PWMS) |
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return -EINVAL; |
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|
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if (pwm >= 0) |
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from = pwm; |
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start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, |
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count, 0); |
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if (pwm >= 0 && start != pwm) |
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return -EEXIST; |
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if (start + count > MAX_PWMS) |
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return -ENOSPC; |
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return start; |
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} |
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|
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static void free_pwms(struct pwm_chip *chip) |
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{ |
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unsigned int i; |
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|
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for (i = 0; i < chip->npwm; i++) { |
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struct pwm_device *pwm = &chip->pwms[i]; |
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radix_tree_delete(&pwm_tree, pwm->pwm); |
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} |
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bitmap_clear(allocated_pwms, chip->base, chip->npwm); |
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|
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kfree(chip->pwms); |
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chip->pwms = NULL; |
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} |
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static struct pwm_chip *pwmchip_find_by_name(const char *name) |
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{ |
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struct pwm_chip *chip; |
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|
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if (!name) |
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return NULL; |
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mutex_lock(&pwm_lock); |
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list_for_each_entry(chip, &pwm_chips, list) { |
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const char *chip_name = dev_name(chip->dev); |
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if (chip_name && strcmp(chip_name, name) == 0) { |
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mutex_unlock(&pwm_lock); |
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return chip; |
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} |
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} |
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mutex_unlock(&pwm_lock); |
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return NULL; |
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} |
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static int pwm_device_request(struct pwm_device *pwm, const char *label) |
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{ |
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int err; |
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|
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if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
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return -EBUSY; |
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if (!try_module_get(pwm->chip->ops->owner)) |
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return -ENODEV; |
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if (pwm->chip->ops->request) { |
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err = pwm->chip->ops->request(pwm->chip, pwm); |
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if (err) { |
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module_put(pwm->chip->ops->owner); |
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return err; |
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} |
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} |
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if (pwm->chip->ops->get_state) { |
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pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state); |
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trace_pwm_get(pwm, &pwm->state); |
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|
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if (IS_ENABLED(CONFIG_PWM_DEBUG)) |
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pwm->last = pwm->state; |
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} |
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set_bit(PWMF_REQUESTED, &pwm->flags); |
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pwm->label = label; |
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return 0; |
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} |
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struct pwm_device * |
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of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) |
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{ |
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struct pwm_device *pwm; |
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|
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/* check, whether the driver supports a third cell for flags */ |
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if (pc->of_pwm_n_cells < 3) |
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return ERR_PTR(-EINVAL); |
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|
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/* flags in the third cell are optional */ |
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if (args->args_count < 2) |
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return ERR_PTR(-EINVAL); |
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if (args->args[0] >= pc->npwm) |
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return ERR_PTR(-EINVAL); |
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pwm = pwm_request_from_chip(pc, args->args[0], NULL); |
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if (IS_ERR(pwm)) |
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return pwm; |
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pwm->args.period = args->args[1]; |
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pwm->args.polarity = PWM_POLARITY_NORMAL; |
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if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED) |
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pwm->args.polarity = PWM_POLARITY_INVERSED; |
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return pwm; |
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} |
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EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); |
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static struct pwm_device * |
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of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) |
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{ |
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struct pwm_device *pwm; |
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|
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/* sanity check driver support */ |
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if (pc->of_pwm_n_cells < 2) |
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return ERR_PTR(-EINVAL); |
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/* all cells are required */ |
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if (args->args_count != pc->of_pwm_n_cells) |
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return ERR_PTR(-EINVAL); |
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if (args->args[0] >= pc->npwm) |
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return ERR_PTR(-EINVAL); |
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pwm = pwm_request_from_chip(pc, args->args[0], NULL); |
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if (IS_ERR(pwm)) |
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return pwm; |
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pwm->args.period = args->args[1]; |
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return pwm; |
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} |
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static void of_pwmchip_add(struct pwm_chip *chip) |
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{ |
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if (!chip->dev || !chip->dev->of_node) |
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return; |
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|
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if (!chip->of_xlate) { |
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chip->of_xlate = of_pwm_simple_xlate; |
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chip->of_pwm_n_cells = 2; |
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} |
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of_node_get(chip->dev->of_node); |
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} |
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static void of_pwmchip_remove(struct pwm_chip *chip) |
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{ |
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if (chip->dev) |
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of_node_put(chip->dev->of_node); |
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} |
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|
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/** |
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* pwm_set_chip_data() - set private chip data for a PWM |
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* @pwm: PWM device |
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* @data: pointer to chip-specific data |
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* |
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* Returns: 0 on success or a negative error code on failure. |
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*/ |
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int pwm_set_chip_data(struct pwm_device *pwm, void *data) |
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{ |
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if (!pwm) |
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return -EINVAL; |
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pwm->chip_data = data; |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(pwm_set_chip_data); |
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|
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/** |
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* pwm_get_chip_data() - get private chip data for a PWM |
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* @pwm: PWM device |
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* |
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* Returns: A pointer to the chip-private data for the PWM device. |
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*/ |
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void *pwm_get_chip_data(struct pwm_device *pwm) |
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{ |
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return pwm ? pwm->chip_data : NULL; |
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} |
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EXPORT_SYMBOL_GPL(pwm_get_chip_data); |
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static bool pwm_ops_check(const struct pwm_chip *chip) |
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{ |
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const struct pwm_ops *ops = chip->ops; |
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/* driver supports legacy, non-atomic operation */ |
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if (ops->config && ops->enable && ops->disable) { |
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if (IS_ENABLED(CONFIG_PWM_DEBUG)) |
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dev_warn(chip->dev, |
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"Driver needs updating to atomic API\n"); |
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return true; |
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} |
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if (!ops->apply) |
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return false; |
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if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state) |
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dev_warn(chip->dev, |
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"Please implement the .get_state() callback\n"); |
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return true; |
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} |
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/** |
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* pwmchip_add_with_polarity() - register a new PWM chip |
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* @chip: the PWM chip to add |
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* @polarity: initial polarity of PWM channels |
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* |
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* Register a new PWM chip. If chip->base < 0 then a dynamically assigned base |
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* will be used. The initial polarity for all channels is specified by the |
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* @polarity parameter. |
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* |
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* Returns: 0 on success or a negative error code on failure. |
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*/ |
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int pwmchip_add_with_polarity(struct pwm_chip *chip, |
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enum pwm_polarity polarity) |
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{ |
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struct pwm_device *pwm; |
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unsigned int i; |
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int ret; |
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if (!chip || !chip->dev || !chip->ops || !chip->npwm) |
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return -EINVAL; |
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if (!pwm_ops_check(chip)) |
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return -EINVAL; |
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mutex_lock(&pwm_lock); |
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ret = alloc_pwms(chip->base, chip->npwm); |
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if (ret < 0) |
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goto out; |
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chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL); |
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if (!chip->pwms) { |
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ret = -ENOMEM; |
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goto out; |
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} |
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chip->base = ret; |
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for (i = 0; i < chip->npwm; i++) { |
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pwm = &chip->pwms[i]; |
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pwm->chip = chip; |
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pwm->pwm = chip->base + i; |
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pwm->hwpwm = i; |
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pwm->state.polarity = polarity; |
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|
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radix_tree_insert(&pwm_tree, pwm->pwm, pwm); |
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} |
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bitmap_set(allocated_pwms, chip->base, chip->npwm); |
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INIT_LIST_HEAD(&chip->list); |
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list_add(&chip->list, &pwm_chips); |
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ret = 0; |
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if (IS_ENABLED(CONFIG_OF)) |
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of_pwmchip_add(chip); |
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out: |
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mutex_unlock(&pwm_lock); |
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if (!ret) |
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pwmchip_sysfs_export(chip); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity); |
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/** |
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* pwmchip_add() - register a new PWM chip |
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* @chip: the PWM chip to add |
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* |
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* Register a new PWM chip. If chip->base < 0 then a dynamically assigned base |
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* will be used. The initial polarity for all channels is normal. |
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* |
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* Returns: 0 on success or a negative error code on failure. |
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*/ |
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int pwmchip_add(struct pwm_chip *chip) |
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{ |
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return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL); |
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} |
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EXPORT_SYMBOL_GPL(pwmchip_add); |
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/** |
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* pwmchip_remove() - remove a PWM chip |
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* @chip: the PWM chip to remove |
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* |
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* Removes a PWM chip. This function may return busy if the PWM chip provides |
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* a PWM device that is still requested. |
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* |
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* Returns: 0 on success or a negative error code on failure. |
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*/ |
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int pwmchip_remove(struct pwm_chip *chip) |
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{ |
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unsigned int i; |
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int ret = 0; |
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pwmchip_sysfs_unexport(chip); |
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mutex_lock(&pwm_lock); |
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for (i = 0; i < chip->npwm; i++) { |
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struct pwm_device *pwm = &chip->pwms[i]; |
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if (test_bit(PWMF_REQUESTED, &pwm->flags)) { |
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ret = -EBUSY; |
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goto out; |
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} |
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} |
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list_del_init(&chip->list); |
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if (IS_ENABLED(CONFIG_OF)) |
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of_pwmchip_remove(chip); |
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free_pwms(chip); |
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out: |
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mutex_unlock(&pwm_lock); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(pwmchip_remove); |
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/** |
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* pwm_request() - request a PWM device |
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* @pwm: global PWM device index |
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* @label: PWM device label |
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* |
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* This function is deprecated, use pwm_get() instead. |
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* |
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* Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on |
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* failure. |
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*/ |
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struct pwm_device *pwm_request(int pwm, const char *label) |
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{ |
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struct pwm_device *dev; |
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int err; |
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if (pwm < 0 || pwm >= MAX_PWMS) |
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return ERR_PTR(-EINVAL); |
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mutex_lock(&pwm_lock); |
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dev = pwm_to_device(pwm); |
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if (!dev) { |
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dev = ERR_PTR(-EPROBE_DEFER); |
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goto out; |
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} |
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err = pwm_device_request(dev, label); |
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if (err < 0) |
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dev = ERR_PTR(err); |
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out: |
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mutex_unlock(&pwm_lock); |
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return dev; |
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} |
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EXPORT_SYMBOL_GPL(pwm_request); |
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|
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/** |
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* pwm_request_from_chip() - request a PWM device relative to a PWM chip |
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* @chip: PWM chip |
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* @index: per-chip index of the PWM to request |
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* @label: a literal description string of this PWM |
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* |
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* Returns: A pointer to the PWM device at the given index of the given PWM |
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* chip. A negative error code is returned if the index is not valid for the |
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* specified PWM chip or if the PWM device cannot be requested. |
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*/ |
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struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, |
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unsigned int index, |
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const char *label) |
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{ |
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struct pwm_device *pwm; |
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int err; |
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if (!chip || index >= chip->npwm) |
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return ERR_PTR(-EINVAL); |
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mutex_lock(&pwm_lock); |
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pwm = &chip->pwms[index]; |
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err = pwm_device_request(pwm, label); |
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if (err < 0) |
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pwm = ERR_PTR(err); |
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mutex_unlock(&pwm_lock); |
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return pwm; |
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} |
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EXPORT_SYMBOL_GPL(pwm_request_from_chip); |
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|
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/** |
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* pwm_free() - free a PWM device |
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* @pwm: PWM device |
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* |
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* This function is deprecated, use pwm_put() instead. |
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*/ |
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void pwm_free(struct pwm_device *pwm) |
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{ |
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pwm_put(pwm); |
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} |
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EXPORT_SYMBOL_GPL(pwm_free); |
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|
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static void pwm_apply_state_debug(struct pwm_device *pwm, |
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const struct pwm_state *state) |
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{ |
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struct pwm_state *last = &pwm->last; |
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struct pwm_chip *chip = pwm->chip; |
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struct pwm_state s1, s2; |
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int err; |
|
|
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if (!IS_ENABLED(CONFIG_PWM_DEBUG)) |
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return; |
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|
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/* No reasonable diagnosis possible without .get_state() */ |
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if (!chip->ops->get_state) |
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return; |
|
|
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/* |
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* *state was just applied. Read out the hardware state and do some |
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* checks. |
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*/ |
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|
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chip->ops->get_state(chip, pwm, &s1); |
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trace_pwm_get(pwm, &s1); |
|
|
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/* |
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* The lowlevel driver either ignored .polarity (which is a bug) or as |
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* best effort inverted .polarity and fixed .duty_cycle respectively. |
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* Undo this inversion and fixup for further tests. |
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*/ |
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if (s1.enabled && s1.polarity != state->polarity) { |
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s2.polarity = state->polarity; |
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s2.duty_cycle = s1.period - s1.duty_cycle; |
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s2.period = s1.period; |
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s2.enabled = s1.enabled; |
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} else { |
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s2 = s1; |
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} |
|
|
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if (s2.polarity != state->polarity && |
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state->duty_cycle < state->period) |
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dev_warn(chip->dev, ".apply ignored .polarity\n"); |
|
|
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if (state->enabled && |
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last->polarity == state->polarity && |
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last->period > s2.period && |
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last->period <= state->period) |
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dev_warn(chip->dev, |
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".apply didn't pick the best available period (requested: %llu, applied: %llu, possible: %llu)\n", |
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state->period, s2.period, last->period); |
|
|
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if (state->enabled && state->period < s2.period) |
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dev_warn(chip->dev, |
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".apply is supposed to round down period (requested: %llu, applied: %llu)\n", |
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state->period, s2.period); |
|
|
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if (state->enabled && |
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last->polarity == state->polarity && |
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last->period == s2.period && |
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last->duty_cycle > s2.duty_cycle && |
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last->duty_cycle <= state->duty_cycle) |
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dev_warn(chip->dev, |
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".apply didn't pick the best available duty cycle (requested: %llu/%llu, applied: %llu/%llu, possible: %llu/%llu)\n", |
|
state->duty_cycle, state->period, |
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s2.duty_cycle, s2.period, |
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last->duty_cycle, last->period); |
|
|
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if (state->enabled && state->duty_cycle < s2.duty_cycle) |
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dev_warn(chip->dev, |
|
".apply is supposed to round down duty_cycle (requested: %llu/%llu, applied: %llu/%llu)\n", |
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state->duty_cycle, state->period, |
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s2.duty_cycle, s2.period); |
|
|
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if (!state->enabled && s2.enabled && s2.duty_cycle > 0) |
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dev_warn(chip->dev, |
|
"requested disabled, but yielded enabled with duty > 0\n"); |
|
|
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/* reapply the state that the driver reported being configured. */ |
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err = chip->ops->apply(chip, pwm, &s1); |
|
if (err) { |
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*last = s1; |
|
dev_err(chip->dev, "failed to reapply current setting\n"); |
|
return; |
|
} |
|
|
|
trace_pwm_apply(pwm, &s1); |
|
|
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chip->ops->get_state(chip, pwm, last); |
|
trace_pwm_get(pwm, last); |
|
|
|
/* reapplication of the current state should give an exact match */ |
|
if (s1.enabled != last->enabled || |
|
s1.polarity != last->polarity || |
|
(s1.enabled && s1.period != last->period) || |
|
(s1.enabled && s1.duty_cycle != last->duty_cycle)) { |
|
dev_err(chip->dev, |
|
".apply is not idempotent (ena=%d pol=%d %llu/%llu) -> (ena=%d pol=%d %llu/%llu)\n", |
|
s1.enabled, s1.polarity, s1.duty_cycle, s1.period, |
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last->enabled, last->polarity, last->duty_cycle, |
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last->period); |
|
} |
|
} |
|
|
|
/** |
|
* pwm_apply_state() - atomically apply a new state to a PWM device |
|
* @pwm: PWM device |
|
* @state: new state to apply |
|
*/ |
|
int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) |
|
{ |
|
struct pwm_chip *chip; |
|
int err; |
|
|
|
if (!pwm || !state || !state->period || |
|
state->duty_cycle > state->period) |
|
return -EINVAL; |
|
|
|
chip = pwm->chip; |
|
|
|
if (state->period == pwm->state.period && |
|
state->duty_cycle == pwm->state.duty_cycle && |
|
state->polarity == pwm->state.polarity && |
|
state->enabled == pwm->state.enabled) |
|
return 0; |
|
|
|
if (chip->ops->apply) { |
|
err = chip->ops->apply(chip, pwm, state); |
|
if (err) |
|
return err; |
|
|
|
trace_pwm_apply(pwm, state); |
|
|
|
pwm->state = *state; |
|
|
|
/* |
|
* only do this after pwm->state was applied as some |
|
* implementations of .get_state depend on this |
|
*/ |
|
pwm_apply_state_debug(pwm, state); |
|
} else { |
|
/* |
|
* FIXME: restore the initial state in case of error. |
|
*/ |
|
if (state->polarity != pwm->state.polarity) { |
|
if (!chip->ops->set_polarity) |
|
return -ENOTSUPP; |
|
|
|
/* |
|
* Changing the polarity of a running PWM is |
|
* only allowed when the PWM driver implements |
|
* ->apply(). |
|
*/ |
|
if (pwm->state.enabled) { |
|
chip->ops->disable(chip, pwm); |
|
pwm->state.enabled = false; |
|
} |
|
|
|
err = chip->ops->set_polarity(chip, pwm, |
|
state->polarity); |
|
if (err) |
|
return err; |
|
|
|
pwm->state.polarity = state->polarity; |
|
} |
|
|
|
if (state->period != pwm->state.period || |
|
state->duty_cycle != pwm->state.duty_cycle) { |
|
err = chip->ops->config(pwm->chip, pwm, |
|
state->duty_cycle, |
|
state->period); |
|
if (err) |
|
return err; |
|
|
|
pwm->state.duty_cycle = state->duty_cycle; |
|
pwm->state.period = state->period; |
|
} |
|
|
|
if (state->enabled != pwm->state.enabled) { |
|
if (state->enabled) { |
|
err = chip->ops->enable(chip, pwm); |
|
if (err) |
|
return err; |
|
} else { |
|
chip->ops->disable(chip, pwm); |
|
} |
|
|
|
pwm->state.enabled = state->enabled; |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
EXPORT_SYMBOL_GPL(pwm_apply_state); |
|
|
|
/** |
|
* pwm_capture() - capture and report a PWM signal |
|
* @pwm: PWM device |
|
* @result: structure to fill with capture result |
|
* @timeout: time to wait, in milliseconds, before giving up on capture |
|
* |
|
* Returns: 0 on success or a negative error code on failure. |
|
*/ |
|
int pwm_capture(struct pwm_device *pwm, struct pwm_capture *result, |
|
unsigned long timeout) |
|
{ |
|
int err; |
|
|
|
if (!pwm || !pwm->chip->ops) |
|
return -EINVAL; |
|
|
|
if (!pwm->chip->ops->capture) |
|
return -ENOSYS; |
|
|
|
mutex_lock(&pwm_lock); |
|
err = pwm->chip->ops->capture(pwm->chip, pwm, result, timeout); |
|
mutex_unlock(&pwm_lock); |
|
|
|
return err; |
|
} |
|
EXPORT_SYMBOL_GPL(pwm_capture); |
|
|
|
/** |
|
* pwm_adjust_config() - adjust the current PWM config to the PWM arguments |
|
* @pwm: PWM device |
|
* |
|
* This function will adjust the PWM config to the PWM arguments provided |
|
* by the DT or PWM lookup table. This is particularly useful to adapt |
|
* the bootloader config to the Linux one. |
|
*/ |
|
int pwm_adjust_config(struct pwm_device *pwm) |
|
{ |
|
struct pwm_state state; |
|
struct pwm_args pargs; |
|
|
|
pwm_get_args(pwm, &pargs); |
|
pwm_get_state(pwm, &state); |
|
|
|
/* |
|
* If the current period is zero it means that either the PWM driver |
|
* does not support initial state retrieval or the PWM has not yet |
|
* been configured. |
|
* |
|
* In either case, we setup the new period and polarity, and assign a |
|
* duty cycle of 0. |
|
*/ |
|
if (!state.period) { |
|
state.duty_cycle = 0; |
|
state.period = pargs.period; |
|
state.polarity = pargs.polarity; |
|
|
|
return pwm_apply_state(pwm, &state); |
|
} |
|
|
|
/* |
|
* Adjust the PWM duty cycle/period based on the period value provided |
|
* in PWM args. |
|
*/ |
|
if (pargs.period != state.period) { |
|
u64 dutycycle = (u64)state.duty_cycle * pargs.period; |
|
|
|
do_div(dutycycle, state.period); |
|
state.duty_cycle = dutycycle; |
|
state.period = pargs.period; |
|
} |
|
|
|
/* |
|
* If the polarity changed, we should also change the duty cycle. |
|
*/ |
|
if (pargs.polarity != state.polarity) { |
|
state.polarity = pargs.polarity; |
|
state.duty_cycle = state.period - state.duty_cycle; |
|
} |
|
|
|
return pwm_apply_state(pwm, &state); |
|
} |
|
EXPORT_SYMBOL_GPL(pwm_adjust_config); |
|
|
|
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); |
|
} |
|
|
|
static struct device_link *pwm_device_link_add(struct device *dev, |
|
struct pwm_device *pwm) |
|
{ |
|
struct device_link *dl; |
|
|
|
if (!dev) { |
|
/* |
|
* No device for the PWM consumer has been provided. It may |
|
* impact the PM sequence ordering: the PWM supplier may get |
|
* suspended before the consumer. |
|
*/ |
|
dev_warn(pwm->chip->dev, |
|
"No consumer device specified to create a link to\n"); |
|
return NULL; |
|
} |
|
|
|
dl = device_link_add(dev, pwm->chip->dev, DL_FLAG_AUTOREMOVE_CONSUMER); |
|
if (!dl) { |
|
dev_err(dev, "failed to create device link to %s\n", |
|
dev_name(pwm->chip->dev)); |
|
return ERR_PTR(-EINVAL); |
|
} |
|
|
|
return dl; |
|
} |
|
|
|
/** |
|
* of_pwm_get() - request a PWM via the PWM framework |
|
* @dev: device for PWM consumer |
|
* @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. |
|
* |
|
* Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
|
* error code on failure. |
|
*/ |
|
struct pwm_device *of_pwm_get(struct device *dev, struct device_node *np, |
|
const char *con_id) |
|
{ |
|
struct pwm_device *pwm = NULL; |
|
struct of_phandle_args args; |
|
struct device_link *dl; |
|
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_err("%s(): can't parse \"pwms\" property\n", __func__); |
|
return ERR_PTR(err); |
|
} |
|
|
|
pc = of_node_to_pwmchip(args.np); |
|
if (IS_ERR(pc)) { |
|
if (PTR_ERR(pc) != -EPROBE_DEFER) |
|
pr_err("%s(): PWM chip not found\n", __func__); |
|
|
|
pwm = ERR_CAST(pc); |
|
goto put; |
|
} |
|
|
|
pwm = pc->of_xlate(pc, &args); |
|
if (IS_ERR(pwm)) |
|
goto put; |
|
|
|
dl = pwm_device_link_add(dev, pwm); |
|
if (IS_ERR(dl)) { |
|
/* of_xlate ended up calling pwm_request_from_chip() */ |
|
pwm_free(pwm); |
|
pwm = ERR_CAST(dl); |
|
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; |
|
} |
|
EXPORT_SYMBOL_GPL(of_pwm_get); |
|
|
|
#if IS_ENABLED(CONFIG_ACPI) |
|
static struct pwm_chip *device_to_pwmchip(struct device *dev) |
|
{ |
|
struct pwm_chip *chip; |
|
|
|
mutex_lock(&pwm_lock); |
|
|
|
list_for_each_entry(chip, &pwm_chips, list) { |
|
struct acpi_device *adev = ACPI_COMPANION(chip->dev); |
|
|
|
if ((chip->dev == dev) || (adev && &adev->dev == dev)) { |
|
mutex_unlock(&pwm_lock); |
|
return chip; |
|
} |
|
} |
|
|
|
mutex_unlock(&pwm_lock); |
|
|
|
return ERR_PTR(-EPROBE_DEFER); |
|
} |
|
#endif |
|
|
|
/** |
|
* acpi_pwm_get() - request a PWM via parsing "pwms" property in ACPI |
|
* @fwnode: firmware node to get the "pwm" property from |
|
* |
|
* Returns the PWM device parsed from the fwnode and index specified in the |
|
* "pwms" property or a negative error-code on failure. |
|
* Values parsed from the device tree are stored in the returned PWM device |
|
* object. |
|
* |
|
* This is analogous to of_pwm_get() except con_id is not yet supported. |
|
* ACPI entries must look like |
|
* Package () {"pwms", Package () |
|
* { <PWM device reference>, <PWM index>, <PWM period> [, <PWM flags>]}} |
|
* |
|
* Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
|
* error code on failure. |
|
*/ |
|
static struct pwm_device *acpi_pwm_get(struct fwnode_handle *fwnode) |
|
{ |
|
struct pwm_device *pwm = ERR_PTR(-ENODEV); |
|
#if IS_ENABLED(CONFIG_ACPI) |
|
struct fwnode_reference_args args; |
|
struct acpi_device *acpi; |
|
struct pwm_chip *chip; |
|
int ret; |
|
|
|
memset(&args, 0, sizeof(args)); |
|
|
|
ret = __acpi_node_get_property_reference(fwnode, "pwms", 0, 3, &args); |
|
if (ret < 0) |
|
return ERR_PTR(ret); |
|
|
|
acpi = to_acpi_device_node(args.fwnode); |
|
if (!acpi) |
|
return ERR_PTR(-EINVAL); |
|
|
|
if (args.nargs < 2) |
|
return ERR_PTR(-EPROTO); |
|
|
|
chip = device_to_pwmchip(&acpi->dev); |
|
if (IS_ERR(chip)) |
|
return ERR_CAST(chip); |
|
|
|
pwm = pwm_request_from_chip(chip, args.args[0], NULL); |
|
if (IS_ERR(pwm)) |
|
return pwm; |
|
|
|
pwm->args.period = args.args[1]; |
|
pwm->args.polarity = PWM_POLARITY_NORMAL; |
|
|
|
if (args.nargs > 2 && args.args[2] & PWM_POLARITY_INVERTED) |
|
pwm->args.polarity = PWM_POLARITY_INVERSED; |
|
#endif |
|
|
|
return pwm; |
|
} |
|
|
|
/** |
|
* pwm_add_table() - register PWM device consumers |
|
* @table: array of consumers to register |
|
* @num: number of consumers in table |
|
*/ |
|
void 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_remove_table() - unregister PWM device consumers |
|
* @table: array of consumers to unregister |
|
* @num: number of consumers in table |
|
*/ |
|
void pwm_remove_table(struct pwm_lookup *table, size_t num) |
|
{ |
|
mutex_lock(&pwm_lookup_lock); |
|
|
|
while (num--) { |
|
list_del(&table->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. |
|
* |
|
* Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
|
* error code on failure. |
|
*/ |
|
struct pwm_device *pwm_get(struct device *dev, const char *con_id) |
|
{ |
|
const char *dev_id = dev ? dev_name(dev) : NULL; |
|
struct pwm_device *pwm; |
|
struct pwm_chip *chip; |
|
struct device_link *dl; |
|
unsigned int best = 0; |
|
struct pwm_lookup *p, *chosen = NULL; |
|
unsigned int match; |
|
int err; |
|
|
|
/* look up via DT first */ |
|
if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) |
|
return of_pwm_get(dev, dev->of_node, con_id); |
|
|
|
/* then lookup via ACPI */ |
|
if (dev && is_acpi_node(dev->fwnode)) { |
|
pwm = acpi_pwm_get(dev->fwnode); |
|
if (!IS_ERR(pwm) || PTR_ERR(pwm) != -ENOENT) |
|
return pwm; |
|
} |
|
|
|
/* |
|
* 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) { |
|
chosen = p; |
|
|
|
if (match != 3) |
|
best = match; |
|
else |
|
break; |
|
} |
|
} |
|
|
|
mutex_unlock(&pwm_lookup_lock); |
|
|
|
if (!chosen) |
|
return ERR_PTR(-ENODEV); |
|
|
|
chip = pwmchip_find_by_name(chosen->provider); |
|
|
|
/* |
|
* If the lookup entry specifies a module, load the module and retry |
|
* the PWM chip lookup. This can be used to work around driver load |
|
* ordering issues if driver's can't be made to properly support the |
|
* deferred probe mechanism. |
|
*/ |
|
if (!chip && chosen->module) { |
|
err = request_module(chosen->module); |
|
if (err == 0) |
|
chip = pwmchip_find_by_name(chosen->provider); |
|
} |
|
|
|
if (!chip) |
|
return ERR_PTR(-EPROBE_DEFER); |
|
|
|
pwm = pwm_request_from_chip(chip, chosen->index, con_id ?: dev_id); |
|
if (IS_ERR(pwm)) |
|
return pwm; |
|
|
|
dl = pwm_device_link_add(dev, pwm); |
|
if (IS_ERR(dl)) { |
|
pwm_free(pwm); |
|
return ERR_CAST(dl); |
|
} |
|
|
|
pwm->args.period = chosen->period; |
|
pwm->args.polarity = chosen->polarity; |
|
|
|
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_set_chip_data(pwm, NULL); |
|
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. |
|
* |
|
* Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
|
* error code on failure. |
|
*/ |
|
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); |
|
|
|
/** |
|
* devm_of_pwm_get() - resource managed of_pwm_get() |
|
* @dev: device for PWM consumer |
|
* @np: device node to get the PWM from |
|
* @con_id: consumer name |
|
* |
|
* This function performs like of_pwm_get() but the acquired PWM device will |
|
* automatically be released on driver detach. |
|
* |
|
* Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
|
* error code on failure. |
|
*/ |
|
struct pwm_device *devm_of_pwm_get(struct device *dev, struct device_node *np, |
|
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 = of_pwm_get(dev, np, con_id); |
|
if (!IS_ERR(pwm)) { |
|
*ptr = pwm; |
|
devres_add(dev, ptr); |
|
} else { |
|
devres_free(ptr); |
|
} |
|
|
|
return pwm; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_of_pwm_get); |
|
|
|
/** |
|
* devm_fwnode_pwm_get() - request a resource managed PWM from firmware node |
|
* @dev: device for PWM consumer |
|
* @fwnode: firmware node to get the PWM from |
|
* @con_id: consumer name |
|
* |
|
* Returns the PWM device parsed from the firmware node. See of_pwm_get() and |
|
* acpi_pwm_get() for a detailed description. |
|
* |
|
* Returns: A pointer to the requested PWM device or an ERR_PTR()-encoded |
|
* error code on failure. |
|
*/ |
|
struct pwm_device *devm_fwnode_pwm_get(struct device *dev, |
|
struct fwnode_handle *fwnode, |
|
const char *con_id) |
|
{ |
|
struct pwm_device **ptr, *pwm = ERR_PTR(-ENODEV); |
|
|
|
ptr = devres_alloc(devm_pwm_release, sizeof(*ptr), GFP_KERNEL); |
|
if (!ptr) |
|
return ERR_PTR(-ENOMEM); |
|
|
|
if (is_of_node(fwnode)) |
|
pwm = of_pwm_get(dev, to_of_node(fwnode), con_id); |
|
else if (is_acpi_node(fwnode)) |
|
pwm = acpi_pwm_get(fwnode); |
|
|
|
if (!IS_ERR(pwm)) { |
|
*ptr = pwm; |
|
devres_add(dev, ptr); |
|
} else { |
|
devres_free(ptr); |
|
} |
|
|
|
return pwm; |
|
} |
|
EXPORT_SYMBOL_GPL(devm_fwnode_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); |
|
|
|
#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]; |
|
struct pwm_state state; |
|
|
|
pwm_get_state(pwm, &state); |
|
|
|
seq_printf(s, " pwm-%-3d (%-20.20s):", i, pwm->label); |
|
|
|
if (test_bit(PWMF_REQUESTED, &pwm->flags)) |
|
seq_puts(s, " requested"); |
|
|
|
if (state.enabled) |
|
seq_puts(s, " enabled"); |
|
|
|
seq_printf(s, " period: %llu ns", state.period); |
|
seq_printf(s, " duty: %llu ns", state.duty_cycle); |
|
seq_printf(s, " polarity: %s", |
|
state.polarity ? "inverse" : "normal"); |
|
|
|
seq_puts(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" : ""); |
|
|
|
pwm_dbg_show(chip, s); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct seq_operations pwm_debugfs_sops = { |
|
.start = pwm_seq_start, |
|
.next = pwm_seq_next, |
|
.stop = pwm_seq_stop, |
|
.show = pwm_seq_show, |
|
}; |
|
|
|
DEFINE_SEQ_ATTRIBUTE(pwm_debugfs); |
|
|
|
static int __init pwm_debugfs_init(void) |
|
{ |
|
debugfs_create_file("pwm", S_IFREG | 0444, NULL, NULL, |
|
&pwm_debugfs_fops); |
|
|
|
return 0; |
|
} |
|
subsys_initcall(pwm_debugfs_init); |
|
#endif /* CONFIG_DEBUG_FS */
|
|
|