From patchwork Tue Aug 28 13:01:18 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 962933 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-pwm-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=microchip.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 4208764Bq0z9s5c for ; Tue, 28 Aug 2018 23:02:42 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727716AbeH1QxR (ORCPT ); Tue, 28 Aug 2018 12:53:17 -0400 Received: from esa1.microchip.iphmx.com ([68.232.147.91]:37723 "EHLO esa1.microchip.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726998AbeH1QxR (ORCPT ); Tue, 28 Aug 2018 12:53:17 -0400 X-IronPort-AV: E=Sophos;i="5.53,299,1531810800"; d="scan'208";a="19626744" Received: from smtpout.microchip.com (HELO email.microchip.com) ([198.175.253.82]) by esa1.microchip.iphmx.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 28 Aug 2018 06:01:42 -0700 Received: from m18063-ThinkPad-T460p.mchp-main.com (10.10.76.4) by chn-sv-exch04.mchp-main.com (10.10.76.105) with Microsoft SMTP Server id 14.3.352.0; Tue, 28 Aug 2018 06:01:42 -0700 From: Claudiu Beznea To: , , , , , , CC: , , , , , Claudiu Beznea Subject: [RESEND PATCH v5 1/9] pwm: extend PWM framework with PWM modes Date: Tue, 28 Aug 2018 16:01:18 +0300 Message-ID: <1535461286-12308-2-git-send-email-claudiu.beznea@microchip.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1535461286-12308-1-git-send-email-claudiu.beznea@microchip.com> References: <1535461286-12308-1-git-send-email-claudiu.beznea@microchip.com> MIME-Version: 1.0 Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org Add basic PWM modes: normal and complementary. These modes should differentiate the single output PWM channels from two outputs PWM channels. These modes could be set as follow: 1. PWM channels with one output per channel: - normal mode 2. PWM channels with two outputs per channel: - normal mode - complementary mode Since users could use a PWM channel with two output as one output PWM channel, the PWM normal mode is allowed to be set for PWM channels with two outputs; in fact PWM normal mode should be supported by all PWMs. The PWM capabilities were implemented per PWM channel. Every PWM controller will register a function to get PWM capabilities. If this is not explicitly set by the driver a default function will be used to retrieve the PWM capabilities (in this case the PWM capabilities will contain only PWM normal mode). This function is set in pwmchip_add_with_polarity() as a member of "struct pwm_chip". To retrieve capabilities the pwm_get_caps() function could be used. Every PWM channel have associated a mode in the PWM state. Proper support was added to get/set PWM mode. The mode could also be set from DT via flag cells. The valid DT modes are located in include/dt-bindings/pwm/pwm.h. Only modes supported by PWM channel could be set. If nothing is specified for a PWM channel, via DT, the first available mode will be used (normally, this will be PWM normal mode). Signed-off-by: Claudiu Beznea --- drivers/pwm/core.c | 124 ++++++++++++++++++++++++++++++++++++++++++++++++++-- drivers/pwm/sysfs.c | 61 ++++++++++++++++++++++++++ include/linux/pwm.h | 39 +++++++++++++++++ 3 files changed, 221 insertions(+), 3 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 1581f6ab1b1f..59a9df9120de 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -136,6 +136,7 @@ struct pwm_device * of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) { struct pwm_device *pwm; + int modebit; /* check, whether the driver supports a third cell for flags */ if (pc->of_pwm_n_cells < 3) @@ -154,9 +155,23 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args) pwm->args.period = args->args[1]; pwm->args.polarity = PWM_POLARITY_NORMAL; + pwm->args.mode = pwm_mode_get_valid(pc, pwm); - if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED) - pwm->args.polarity = PWM_POLARITY_INVERSED; + if (args->args_count > 2) { + if (args->args[2] & PWM_POLARITY_INVERTED) + pwm->args.polarity = PWM_POLARITY_INVERSED; + + for (modebit = PWMC_MODE_COMPLEMENTARY_BIT; + modebit < PWMC_MODE_CNT; modebit++) { + unsigned long mode = BIT(modebit); + + if ((args->args[2] & mode) && + pwm_mode_valid(pwm, mode)) { + pwm->args.mode = mode; + break; + } + } + } return pwm; } @@ -183,6 +198,7 @@ of_pwm_simple_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) return pwm; pwm->args.period = args->args[1]; + pwm->args.mode = pwm_mode_get_valid(pc, pwm); return pwm; } @@ -250,6 +266,97 @@ static bool pwm_ops_check(const struct pwm_ops *ops) } /** + * pwm_get_caps() - get PWM capabilities of a PWM device + * @chip: PWM chip + * @pwm: PWM device to get the capabilities for + * @caps: returned capabilities + * + * Returns: 0 on success or a negative error code on failure + */ +int pwm_get_caps(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_caps *caps) +{ + if (!chip || !pwm || !caps) + return -EINVAL; + + if (chip->ops && chip->ops->get_caps) + pwm->chip->ops->get_caps(chip, pwm, caps); + else if (chip->get_default_caps) + chip->get_default_caps(caps); + + return 0; +} +EXPORT_SYMBOL_GPL(pwm_get_caps); + +static void pwmchip_get_default_caps(struct pwm_caps *caps) +{ + static const struct pwm_caps default_caps = { + .modes = PWMC_MODE(NORMAL), + }; + + if (!caps) + return; + + *caps = default_caps; +} + +/** + * pwm_mode_get_valid() - get the first available valid mode for PWM + * @chip: PWM chip + * @pwm: PWM device to get the valid mode for + * + * Returns: first valid mode for PWM device + */ +unsigned long pwm_mode_get_valid(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct pwm_caps caps; + + if (pwm_get_caps(chip, pwm, &caps)) + return PWMC_MODE(NORMAL); + + return BIT(ffs(caps.modes) - 1); +} +EXPORT_SYMBOL_GPL(pwm_mode_get_valid); + +/** + * pwm_mode_valid() - check if mode is valid for PWM device + * @pwm: PWM device + * @mode: PWM mode to check if valid + * + * Returns: true if mode is valid and false otherwise + */ +bool pwm_mode_valid(struct pwm_device *pwm, unsigned long mode) +{ + struct pwm_caps caps; + + if (!pwm || !mode) + return false; + + if (hweight_long(mode) != 1 || ffs(mode) - 1 >= PWMC_MODE_CNT) + return false; + + if (pwm_get_caps(pwm->chip, pwm, &caps)) + return false; + + return (caps.modes & mode); +} +EXPORT_SYMBOL_GPL(pwm_mode_valid); + +const char *pwm_mode_desc(struct pwm_device *pwm, unsigned long mode) +{ + static const char * const modes[] = { + "invalid", + "normal", + "complementary", + }; + + if (!pwm_mode_valid(pwm, mode)) + return modes[0]; + + return modes[ffs(mode)]; +} + +/** * pwmchip_add_with_polarity() - register a new PWM chip * @chip: the PWM chip to add * @polarity: initial polarity of PWM channels @@ -275,6 +382,8 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, mutex_lock(&pwm_lock); + chip->get_default_caps = pwmchip_get_default_caps; + ret = alloc_pwms(chip->base, chip->npwm); if (ret < 0) goto out; @@ -294,6 +403,7 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->pwm = chip->base + i; pwm->hwpwm = i; pwm->state.polarity = polarity; + pwm->state.mode = pwm_mode_get_valid(chip, pwm); if (chip->ops->get_state) chip->ops->get_state(chip, pwm, &pwm->state); @@ -469,7 +579,8 @@ int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state) int err; if (!pwm || !state || !state->period || - state->duty_cycle > state->period) + state->duty_cycle > state->period || + !pwm_mode_valid(pwm, state->mode)) return -EINVAL; if (!memcmp(state, &pwm->state, sizeof(*state))) @@ -530,6 +641,9 @@ int pwm_apply_state(struct pwm_device *pwm, struct pwm_state *state) pwm->state.enabled = state->enabled; } + + /* No mode support for non-atomic PWM. */ + pwm->state.mode = state->mode; } return 0; @@ -579,6 +693,8 @@ int pwm_adjust_config(struct pwm_device *pwm) pwm_get_args(pwm, &pargs); pwm_get_state(pwm, &state); + state.mode = pargs.mode; + /* * 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 @@ -850,6 +966,7 @@ struct pwm_device *pwm_get(struct device *dev, const char *con_id) pwm->args.period = chosen->period; pwm->args.polarity = chosen->polarity; + pwm->args.mode = pwm_mode_get_valid(chip, pwm); return pwm; } @@ -999,6 +1116,7 @@ static void pwm_dbg_show(struct pwm_chip *chip, struct seq_file *s) seq_printf(s, " duty: %u ns", state.duty_cycle); seq_printf(s, " polarity: %s", state.polarity ? "inverse" : "normal"); + seq_printf(s, " mode: %s", pwm_mode_desc(pwm, state.mode)); seq_puts(s, "\n"); } diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 83f2b0b15712..785eda0b1e67 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -223,11 +223,71 @@ static ssize_t capture_show(struct device *child, return sprintf(buf, "%u %u\n", result.period, result.duty_cycle); } +static ssize_t mode_show(struct device *child, + struct device_attribute *attr, + char *buf) +{ + struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_state state; + unsigned long mode; + int modebit, len = 0; + + pwm_get_state(pwm, &state); + + for (modebit = PWMC_MODE_NORMAL_BIT; + modebit < PWMC_MODE_CNT; modebit++) { + mode = BIT(modebit); + if (pwm_mode_valid(pwm, mode)) { + if (state.mode == mode) + len += scnprintf(buf + len, + PAGE_SIZE - len, "[%s] ", + pwm_mode_desc(pwm, mode)); + else + len += scnprintf(buf + len, + PAGE_SIZE - len, "%s ", + pwm_mode_desc(pwm, mode)); + } + } + + len += scnprintf(buf + len, PAGE_SIZE - len, "\n"); + return len; +} + +static ssize_t mode_store(struct device *child, + struct device_attribute *attr, + const char *buf, size_t size) +{ + struct pwm_export *export = child_to_pwm_export(child); + struct pwm_device *pwm = export->pwm; + struct pwm_state state; + unsigned long mode; + int modebit, ret; + + for (modebit = PWMC_MODE_NORMAL_BIT; + modebit < PWMC_MODE_CNT; modebit++) { + mode = BIT(modebit); + if (sysfs_streq(buf, pwm_mode_desc(pwm, mode))) + break; + } + + if (modebit == PWMC_MODE_CNT) + return -EINVAL; + + mutex_lock(&export->lock); + pwm_get_state(pwm, &state); + state.mode = mode; + ret = pwm_apply_state(pwm, &state); + mutex_unlock(&export->lock); + + return ret ? : size; +} + static DEVICE_ATTR_RW(period); static DEVICE_ATTR_RW(duty_cycle); static DEVICE_ATTR_RW(enable); static DEVICE_ATTR_RW(polarity); static DEVICE_ATTR_RO(capture); +static DEVICE_ATTR_RW(mode); static struct attribute *pwm_attrs[] = { &dev_attr_period.attr, @@ -235,6 +295,7 @@ static struct attribute *pwm_attrs[] = { &dev_attr_enable.attr, &dev_attr_polarity.attr, &dev_attr_capture.attr, + &dev_attr_mode.attr, NULL }; ATTRIBUTE_GROUPS(pwm); diff --git a/include/linux/pwm.h b/include/linux/pwm.h index 56518adc31dd..a4ce4ad7edf0 100644 --- a/include/linux/pwm.h +++ b/include/linux/pwm.h @@ -26,9 +26,32 @@ enum pwm_polarity { }; /** + * PWM modes capabilities + * @PWMC_MODE_NORMAL_BIT: PWM has one output + * @PWMC_MODE_COMPLEMENTARY_BIT: PWM has 2 outputs with opposite polarities + * @PWMC_MODE_CNT: PWM modes count + */ +enum { + PWMC_MODE_NORMAL_BIT, + PWMC_MODE_COMPLEMENTARY_BIT, + PWMC_MODE_CNT, +}; + +#define PWMC_MODE(name) BIT(PWMC_MODE_##name##_BIT) + +/** + * struct pwm_caps - PWM capabilities + * @modes: PWM modes + */ +struct pwm_caps { + unsigned long modes; +}; + +/** * struct pwm_args - board-dependent PWM arguments * @period: reference period * @polarity: reference polarity + * @mode: reference mode * * This structure describes board-dependent arguments attached to a PWM * device. These arguments are usually retrieved from the PWM lookup table or @@ -41,6 +64,7 @@ enum pwm_polarity { struct pwm_args { unsigned int period; enum pwm_polarity polarity; + unsigned long mode; }; enum { @@ -53,12 +77,14 @@ enum { * @period: PWM period (in nanoseconds) * @duty_cycle: PWM duty cycle (in nanoseconds) * @polarity: PWM polarity + * @mode: PWM mode * @enabled: PWM enabled status */ struct pwm_state { unsigned int period; unsigned int duty_cycle; enum pwm_polarity polarity; + unsigned long mode; bool enabled; }; @@ -181,6 +207,7 @@ static inline void pwm_init_state(const struct pwm_device *pwm, state->period = args.period; state->polarity = args.polarity; state->duty_cycle = 0; + state->mode = args.mode; } /** @@ -254,6 +281,7 @@ pwm_set_relative_duty_cycle(struct pwm_state *state, unsigned int duty_cycle, * @get_state: get the current PWM state. This function is only * called once per PWM device when the PWM chip is * registered. + * @get_caps: get PWM capabilities. * @dbg_show: optional routine to show contents in debugfs * @owner: helps prevent removal of modules exporting active PWMs */ @@ -272,6 +300,8 @@ struct pwm_ops { struct pwm_state *state); void (*get_state)(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state); + void (*get_caps)(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_caps *caps); #ifdef CONFIG_DEBUG_FS void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s); #endif @@ -287,6 +317,7 @@ struct pwm_ops { * @npwm: number of PWMs controlled by this chip * @pwms: array of PWM devices allocated by the framework * @of_xlate: request a PWM device given a device tree PWM specifier + * @get_default_caps: get default PWM capabilities * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier */ struct pwm_chip { @@ -300,6 +331,7 @@ struct pwm_chip { struct pwm_device * (*of_xlate)(struct pwm_chip *pc, const struct of_phandle_args *args); + void (*get_default_caps)(struct pwm_caps *caps); unsigned int of_pwm_n_cells; }; @@ -438,6 +470,12 @@ struct pwm_device *pwm_request_from_chip(struct pwm_chip *chip, unsigned int index, const char *label); +int pwm_get_caps(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_caps *caps); +unsigned long pwm_mode_get_valid(struct pwm_chip *chip, + struct pwm_device *pwm); +bool pwm_mode_valid(struct pwm_device *pwm, unsigned long mode); +const char *pwm_mode_desc(struct pwm_device *pwm, unsigned long mode); struct pwm_device *of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args); @@ -592,6 +630,7 @@ static inline void pwm_apply_args(struct pwm_device *pwm) state.enabled = false; state.polarity = pwm->args.polarity; state.period = pwm->args.period; + state.mode = pwm->args.mode; pwm_apply_state(pwm, &state); }