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1188829abc
This allows to log all calls to the driver's lowlevel functions which simplifies debugging in some cases. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
1238 lines
28 KiB
C
1238 lines
28 KiB
C
// 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 <s.hauer@pengutronix.de>
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* Copyright (C) 2011-2012 Avionic Design GmbH
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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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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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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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if (pwm >= MAX_PWMS)
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return -EINVAL;
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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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static void free_pwms(struct pwm_chip *chip)
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{
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unsigned int i;
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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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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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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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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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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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/* 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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/* 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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/* 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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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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* 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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* 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_ops *ops)
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{
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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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return true;
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/* driver supports atomic operation */
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if (ops->apply)
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return true;
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return false;
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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->ops))
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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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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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* 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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* 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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* pwm_apply_state() - atomically apply a new state to a PWM device
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* @pwm: PWM device
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* @state: new state to apply
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*/
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int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state)
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{
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struct pwm_chip *chip;
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int err;
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if (!pwm || !state || !state->period ||
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state->duty_cycle > state->period)
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return -EINVAL;
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chip = pwm->chip;
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if (state->period == pwm->state.period &&
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state->duty_cycle == pwm->state.duty_cycle &&
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state->polarity == pwm->state.polarity &&
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state->enabled == pwm->state.enabled)
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return 0;
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if (chip->ops->apply) {
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err = chip->ops->apply(chip, pwm, state);
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if (err)
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return err;
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trace_pwm_apply(pwm, state);
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pwm->state = *state;
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} else {
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/*
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* FIXME: restore the initial state in case of error.
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*/
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if (state->polarity != pwm->state.polarity) {
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if (!chip->ops->set_polarity)
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return -ENOTSUPP;
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/*
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* Changing the polarity of a running PWM is
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* only allowed when the PWM driver implements
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* ->apply().
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*/
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if (pwm->state.enabled) {
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chip->ops->disable(chip, pwm);
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pwm->state.enabled = false;
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}
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err = chip->ops->set_polarity(chip, pwm,
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state->polarity);
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if (err)
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return err;
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pwm->state.polarity = state->polarity;
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}
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if (state->period != pwm->state.period ||
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state->duty_cycle != pwm->state.duty_cycle) {
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err = chip->ops->config(pwm->chip, pwm,
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state->duty_cycle,
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state->period);
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if (err)
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return err;
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pwm->state.duty_cycle = state->duty_cycle;
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pwm->state.period = state->period;
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}
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if (state->enabled != pwm->state.enabled) {
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if (state->enabled) {
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err = chip->ops->enable(chip, pwm);
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if (err)
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return err;
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} else {
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chip->ops->disable(chip, pwm);
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}
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pwm->state.enabled = state->enabled;
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}
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(pwm_apply_state);
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/**
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* pwm_capture() - capture and report a PWM signal
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* @pwm: PWM device
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* @result: structure to fill with capture result
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* @timeout: time to wait, in milliseconds, before giving up on capture
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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_capture(struct pwm_device *pwm, struct pwm_capture *result,
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unsigned long timeout)
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{
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int err;
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|
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if (!pwm || !pwm->chip->ops)
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return -EINVAL;
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|
|
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: %u ns", state.period);
|
|
seq_printf(s, " duty: %u 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_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 */
|