// SPDX-License-Identifier: GPL-2.0-or-later /* * Generic pwmlib implementation * * Copyright (C) 2011 Sascha Hauer * Copyright (C) 2011-2012 Avionic Design GmbH */ #include #include #include #include #include #include #include #include #include #include #include #include #define CREATE_TRACE_POINTS #include #define MAX_PWMS 1024 static DEFINE_MUTEX(pwm_lookup_lock); static LIST_HEAD(pwm_lookup_list); static DEFINE_MUTEX(pwm_lock); static LIST_HEAD(pwm_chips); static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); static RADIX_TREE(pwm_tree, GFP_KERNEL); static struct pwm_device *pwm_to_device(unsigned int pwm) { return radix_tree_lookup(&pwm_tree, pwm); } static int alloc_pwms(int pwm, unsigned int count) { unsigned int from = 0; unsigned int start; if (pwm >= MAX_PWMS) return -EINVAL; if (pwm >= 0) from = pwm; start = bitmap_find_next_zero_area(allocated_pwms, MAX_PWMS, from, count, 0); if (pwm >= 0 && start != pwm) return -EEXIST; if (start + count > MAX_PWMS) return -ENOSPC; return start; } static void free_pwms(struct pwm_chip *chip) { unsigned int i; for (i = 0; i < chip->npwm; i++) { struct pwm_device *pwm = &chip->pwms[i]; radix_tree_delete(&pwm_tree, pwm->pwm); } bitmap_clear(allocated_pwms, chip->base, chip->npwm); kfree(chip->pwms); chip->pwms = NULL; } static struct pwm_chip *pwmchip_find_by_name(const char *name) { struct pwm_chip *chip; if (!name) return NULL; mutex_lock(&pwm_lock); list_for_each_entry(chip, &pwm_chips, list) { const char *chip_name = dev_name(chip->dev); if (chip_name && strcmp(chip_name, name) == 0) { mutex_unlock(&pwm_lock); return chip; } } mutex_unlock(&pwm_lock); return NULL; } static int pwm_device_request(struct pwm_device *pwm, const char *label) { int err; if (test_bit(PWMF_REQUESTED, &pwm->flags)) return -EBUSY; if (!try_module_get(pwm->chip->ops->owner)) return -ENODEV; if (pwm->chip->ops->request) { err = pwm->chip->ops->request(pwm->chip, pwm); if (err) { module_put(pwm->chip->ops->owner); return err; } } if (pwm->chip->ops->get_state) { pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state); trace_pwm_get(pwm, &pwm->state); if (IS_ENABLED(PWM_DEBUG)) pwm->last = pwm->state; } set_bit(PWMF_REQUESTED, &pwm->flags); pwm->label = label; return 0; } struct pwm_device * of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) { struct pwm_device *pwm; /* check, whether the driver supports a third cell for flags */ if (pc->of_pwm_n_cells < 3) return ERR_PTR(-EINVAL); /* flags in the third cell are optional */ if (args->args_count < 2) return ERR_PTR(-EINVAL); if (args->args[0] >= pc->npwm) return ERR_PTR(-EINVAL); pwm = pwm_request_from_chip(pc, args->args[0], NULL); if (IS_ERR(pwm)) return pwm; pwm->args.period = args->args[1]; pwm->args.polarity = PWM_POLARITY_NORMAL; if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED) pwm->args.polarity = PWM_POLARITY_INVERSED; return pwm; } EXPORT_SYMBOL_GPL(of_pwm_xlate_with_flags); static struct pwm_device * of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) { struct pwm_device *pwm; /* sanity check driver support */ if (pc->of_pwm_n_cells < 2) return ERR_PTR(-EINVAL); /* all cells are required */ if (args->args_count != pc->of_pwm_n_cells) return ERR_PTR(-EINVAL); if (args->args[0] >= pc->npwm) return ERR_PTR(-EINVAL); pwm = pwm_request_from_chip(pc, args->args[0], NULL); if (IS_ERR(pwm)) return pwm; pwm->args.period = args->args[1]; return pwm; } static void of_pwmchip_add(struct pwm_chip *chip) { if (!chip->dev || !chip->dev->of_node) return; if (!chip->of_xlate) { chip->of_xlate = of_pwm_simple_xlate; chip->of_pwm_n_cells = 2; } of_node_get(chip->dev->of_node); } static void of_pwmchip_remove(struct pwm_chip *chip) { if (chip->dev) of_node_put(chip->dev->of_node); } /** * pwm_set_chip_data() - set private chip data for a PWM * @pwm: PWM device * @data: pointer to chip-specific data * * Returns: 0 on success or a negative error code on failure. */ int pwm_set_chip_data(struct pwm_device *pwm, void *data) { if (!pwm) return -EINVAL; pwm->chip_data = data; return 0; } EXPORT_SYMBOL_GPL(pwm_set_chip_data); /** * pwm_get_chip_data() - get private chip data for a PWM * @pwm: PWM device * * Returns: A pointer to the chip-private data for the PWM device. */ void *pwm_get_chip_data(struct pwm_device *pwm) { return pwm ? pwm->chip_data : NULL; } EXPORT_SYMBOL_GPL(pwm_get_chip_data); static bool pwm_ops_check(const struct pwm_chip *chip) { const struct pwm_ops *ops = chip->ops; /* driver supports legacy, non-atomic operation */ if (ops->config && ops->enable && ops->disable) { if (IS_ENABLED(CONFIG_PWM_DEBUG)) dev_warn(chip->dev, "Driver needs updating to atomic API\n"); return true; } if (!ops->apply) return false; if (IS_ENABLED(CONFIG_PWM_DEBUG) && !ops->get_state) dev_warn(chip->dev, "Please implement the .get_state() callback\n"); return true; } /** * pwmchip_add_with_polarity() - register a new PWM chip * @chip: the PWM chip to add * @polarity: initial polarity of PWM channels * * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base * will be used. The initial polarity for all channels is specified by the * @polarity parameter. * * Returns: 0 on success or a negative error code on failure. */ int pwmchip_add_with_polarity(struct pwm_chip *chip, enum pwm_polarity polarity) { struct pwm_device *pwm; unsigned int i; int ret; if (!chip || !chip->dev || !chip->ops || !chip->npwm) return -EINVAL; if (!pwm_ops_check(chip)) return -EINVAL; mutex_lock(&pwm_lock); ret = alloc_pwms(chip->base, chip->npwm); if (ret < 0) goto out; chip->pwms = kcalloc(chip->npwm, sizeof(*pwm), GFP_KERNEL); if (!chip->pwms) { ret = -ENOMEM; goto out; } chip->base = ret; for (i = 0; i < chip->npwm; i++) { pwm = &chip->pwms[i]; pwm->chip = chip; pwm->pwm = chip->base + i; pwm->hwpwm = i; pwm->state.polarity = polarity; radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } bitmap_set(allocated_pwms, chip->base, chip->npwm); INIT_LIST_HEAD(&chip->list); list_add(&chip->list, &pwm_chips); ret = 0; if (IS_ENABLED(CONFIG_OF)) of_pwmchip_add(chip); out: mutex_unlock(&pwm_lock); if (!ret) pwmchip_sysfs_export(chip); return ret; } EXPORT_SYMBOL_GPL(pwmchip_add_with_polarity); /** * pwmchip_add() - register a new PWM chip * @chip: the PWM chip to add * * Register a new PWM chip. If chip->base < 0 then a dynamically assigned base * will be used. The initial polarity for all channels is normal. * * Returns: 0 on success or a negative error code on failure. */ int pwmchip_add(struct pwm_chip *chip) { return pwmchip_add_with_polarity(chip, PWM_POLARITY_NORMAL); } EXPORT_SYMBOL_GPL(pwmchip_add); /** * pwmchip_remove() - remove a PWM chip * @chip: the PWM chip to remove * * Removes a PWM chip. This function may return busy if the PWM chip provides * a PWM device that is still requested. * * Returns: 0 on success or a negative error code on failure. */ int pwmchip_remove(struct pwm_chip *chip) { unsigned int i; int ret = 0; pwmchip_sysfs_unexport(chip); mutex_lock(&pwm_lock); for (i = 0; i < chip->npwm; i++) { struct pwm_device *pwm = &chip->pwms[i]; if (test_bit(PWMF_REQUESTED, &pwm->flags)) { ret = -EBUSY; goto out; } } list_del_init(&chip->list); if (IS_ENABLED(CONFIG_OF)) of_pwmchip_remove(chip); free_pwms(chip); out: mutex_unlock(&pwm_lock); return ret; } EXPORT_SYMBOL_GPL(pwmchip_remove); /** * pwm_request() - request a PWM device * @pwm: global PWM device index * @label: PWM device label * * This function is deprecated, use pwm_get() instead. * * Returns: A pointer to a PWM device or an ERR_PTR()-encoded error code on * failure. */ struct pwm_device *pwm_request(int pwm, const char *label) { struct pwm_device *dev; int err; if (pwm < 0 || pwm >= MAX_PWMS) return ERR_PTR(-EINVAL); mutex_lock(&pwm_lock); dev = pwm_to_device(pwm); if (!dev) { dev = ERR_PTR(-EPROBE_DEFER); goto out; } err = pwm_device_request(dev, label); if (err < 0) dev = ERR_PTR(err); out: mutex_unlock(&pwm_lock); return dev; } EXPORT_SYMBOL_GPL(pwm_request); /** * pwm_request_from_chip() - request a PWM device relative to a PWM chip * @chip: PWM chip * @index: per-chip index of the PWM to request * @label: a literal description string of this PWM * * Returns: A pointer to the PWM device at the given index of the given PWM * chip. A negative error code is returned if the index is not valid for the * specified PWM chip or if the PWM device cannot be requested. */ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, unsigned int index, const char *label) { struct pwm_device *pwm; int err; if (!chip || index >= chip->npwm) return ERR_PTR(-EINVAL); mutex_lock(&pwm_lock); pwm = &chip->pwms[index]; err = pwm_device_request(pwm, label); if (err < 0) pwm = ERR_PTR(err); mutex_unlock(&pwm_lock); return pwm; } EXPORT_SYMBOL_GPL(pwm_request_from_chip); /** * pwm_free() - free a PWM device * @pwm: PWM device * * This function is deprecated, use pwm_put() instead. */ void pwm_free(struct pwm_device *pwm) { pwm_put(pwm); } EXPORT_SYMBOL_GPL(pwm_free); void pwm_apply_state_debug(struct pwm_device *pwm, const struct pwm_state *state) { struct pwm_state *last = &pwm->last; struct pwm_chip *chip = pwm->chip; struct pwm_state s1, s2; int err; if (!IS_ENABLED(CONFIG_PWM_DEBUG)) return; /* No reasonable diagnosis possible without .get_state() */ if (!chip->ops->get_state) return; /* * *state was just applied. Read out the hardware state and do some * checks. */ chip->ops->get_state(chip, pwm, &s1); trace_pwm_get(pwm, &s1); /* * The lowlevel driver either ignored .polarity (which is a bug) or as * best effort inverted .polarity and fixed .duty_cycle respectively. * Undo this inversion and fixup for further tests. */ if (s1.enabled && s1.polarity != state->polarity) { s2.polarity = state->polarity; s2.duty_cycle = s1.period - s1.duty_cycle; s2.period = s1.period; s2.enabled = s1.enabled; } else { s2 = s1; } if (s2.polarity != state->polarity && state->duty_cycle < state->period) dev_warn(chip->dev, ".apply ignored .polarity\n"); if (state->enabled && last->polarity == state->polarity && last->period > s2.period && last->period <= state->period) dev_warn(chip->dev, ".apply didn't pick the best available period (requested: %u, applied: %u, possible: %u)\n", state->period, s2.period, last->period); if (state->enabled && state->period < s2.period) dev_warn(chip->dev, ".apply is supposed to round down period (requested: %u, applied: %u)\n", state->period, s2.period); if (state->enabled && last->polarity == state->polarity && last->period == s2.period && last->duty_cycle > s2.duty_cycle && last->duty_cycle <= state->duty_cycle) dev_warn(chip->dev, ".apply didn't pick the best available duty cycle (requested: %u/%u, applied: %u/%u, possible: %u/%u)\n", state->duty_cycle, state->period, s2.duty_cycle, s2.period, last->duty_cycle, last->period); if (state->enabled && state->duty_cycle < s2.duty_cycle) dev_warn(chip->dev, ".apply is supposed to round down duty_cycle (requested: %u/%u, applied: %u/%u)\n", state->duty_cycle, state->period, s2.duty_cycle, s2.period); if (!state->enabled && s2.enabled && s2.duty_cycle > 0) dev_warn(chip->dev, "requested disabled, but yielded enabled with duty > 0"); /* reapply the state that the driver reported being configured. */ err = chip->ops->apply(chip, pwm, &s1); if (err) { *last = s1; dev_err(chip->dev, "failed to reapply current setting\n"); return; } trace_pwm_apply(pwm, &s1); 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 %u/%u) -> (ena=%d pol=%d %u/%u)\n", s1.enabled, s1.polarity, s1.duty_cycle, s1.period, last->enabled, last->polarity, last->duty_cycle, 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 () * { , , [, ]}} * * 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 */