!Edrivers/hsi/hsi.c
</chapter>
+ <chapter id="pwm">
+ <title>Pulse-Width Modulation (PWM)</title>
+ <para>
+ Pulse-width modulation is a modulation technique primarily used to
+ control power supplied to electrical devices.
+ </para>
+ <para>
+ The PWM framework provides an abstraction for providers and consumers
+ of PWM signals. A controller that provides one or more PWM signals is
+ registered as <structname>struct pwm_chip</structname>. Providers are
+ expected to embed this structure in a driver-specific structure. This
+ structure contains fields that describe a particular chip.
+ </para>
+ <para>
+ A chip exposes one or more PWM signal sources, each of which exposed
+ as a <structname>struct pwm_device</structname>. Operations can be
+ performed on PWM devices to control the period, duty cycle, polarity
+ and active state of the signal.
+ </para>
+ <para>
+ Note that PWM devices are exclusive resources: they can always only be
+ used by one consumer at a time.
+ </para>
+!Iinclude/linux/pwm.h
+!Edrivers/pwm/core.c
+ </chapter>
+
</book>
--- /dev/null
+* NXP LPC18xx State Configurable Timer - Pulse Width Modulator driver
+
+Required properties:
+ - compatible: Should be "nxp,lpc1850-sct-pwm"
+ - reg: Should contain physical base address and length of pwm registers.
+ - clocks: Must contain an entry for each entry in clock-names.
+ See ../clock/clock-bindings.txt for details.
+ - clock-names: Must include the following entries.
+ - pwm: PWM operating clock.
+ - #pwm-cells: Should be 3. See pwm.txt in this directory for the description
+ of the cells format.
+
+Example:
+ pwm: pwm@40000000 {
+ compatible = "nxp,lpc1850-sct-pwm";
+ reg = <0x40000000 0x1000>;
+ clocks =<&ccu1 CLK_CPU_SCT>;
+ clock-names = "pwm";
+ #pwm-cells = <3>;
+ };
To compile this driver as a module, choose M here: the module
will be called pwm-lp3943.
+config PWM_LPC18XX_SCT
+ tristate "LPC18xx/43xx PWM/SCT support"
+ depends on ARCH_LPC18XX
+ help
+ Generic PWM framework driver for NXP LPC18xx PWM/SCT which
+ supports 16 channels.
+ A maximum of 15 channels can be requested simultaneously and
+ must have the same period.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pwm-lpc18xx-sct.
+
config PWM_LPC32XX
tristate "LPC32XX PWM support"
depends on ARCH_LPC32XX
obj-$(CONFIG_PWM_IMX) += pwm-imx.o
obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o
obj-$(CONFIG_PWM_LP3943) += pwm-lp3943.o
+obj-$(CONFIG_PWM_LPC18XX_SCT) += pwm-lpc18xx-sct.o
obj-$(CONFIG_PWM_LPC32XX) += pwm-lpc32xx.o
obj-$(CONFIG_PWM_LPSS) += pwm-lpss.o
obj-$(CONFIG_PWM_LPSS_PCI) += pwm-lpss-pci.o
* 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)
{
/**
* 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)
{
* 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)
*
* 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)
{
*
* 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)
{
/**
* pwm_request() - request a PWM device
- * @pwm_id: global PWM device index
+ * @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)
{
* @index: per-chip index of the PWM to request
* @label: a literal description string of this PWM
*
- * Returns the PWM at the given index of the given PWM chip. A negative error
- * code is returned if the index is not valid for the specified PWM chip or
- * if the PWM device cannot be requested.
+ * 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,
* @pwm: PWM device
* @duty_ns: "on" time (in nanoseconds)
* @period_ns: duration (in nanoseconds) of one cycle
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns)
{
* @pwm: PWM device
* @polarity: new polarity of the PWM signal
*
- * Note that the polarity cannot be configured while the PWM device is enabled
+ * Note that the polarity cannot be configured while the PWM device is
+ * enabled.
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity)
{
if (!pwm->chip->ops->set_polarity)
return -ENOSYS;
- if (test_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm_is_enabled(pwm))
return -EBUSY;
err = pwm->chip->ops->set_polarity(pwm->chip, pwm, polarity);
/**
* pwm_enable() - start a PWM output toggling
* @pwm: PWM device
+ *
+ * Returns: 0 on success or a negative error code on failure.
*/
int pwm_enable(struct pwm_device *pwm)
{
* 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_node *np, const char *con_id)
{
*
* 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)
{
*
* 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)
{
*
* 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)
* pwm_can_sleep() - report whether PWM access will sleep
* @pwm: PWM device
*
- * It returns true if accessing the PWM can sleep, false otherwise.
+ * Returns: True if accessing the PWM can sleep, false otherwise.
*/
bool pwm_can_sleep(struct pwm_device *pwm)
{
if (test_bit(PWMF_REQUESTED, &pwm->flags))
seq_puts(s, " requested");
- if (test_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm_is_enabled(pwm))
seq_puts(s, " enabled");
seq_puts(s, "\n");
return 0;
}
-
subsys_initcall(pwm_debugfs_init);
#endif /* CONFIG_DEBUG_FS */
static const struct of_device_id atmel_hlcdc_dt_ids[] = {
{
+ .compatible = "atmel,at91sam9n12-hlcdc",
+ /* 9n12 has same errata as 9x5 HLCDC PWM */
+ .data = &atmel_hlcdc_pwm_at91sam9x5_errata,
+ },
+ {
.compatible = "atmel,at91sam9x5-hlcdc",
.data = &atmel_hlcdc_pwm_at91sam9x5_errata,
},
tcbpwm->duty = duty;
/* If the PWM is enabled, call enable to apply the new conf */
- if (test_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm_is_enabled(pwm))
atmel_tcb_pwm_enable(chip, pwm);
return 0;
u32 val;
int ret;
- if (test_bit(PWMF_ENABLED, &pwm->flags) && (period_ns != pwm->period)) {
+ if (pwm_is_enabled(pwm) && (period_ns != pwm_get_period(pwm))) {
dev_err(chip->dev, "cannot change PWM period while enabled\n");
return -EBUSY;
}
* If the PWM channel is enabled, only update CDTY by using the update
* register, it needs to set bit 10 of CMR to 0
*/
- if (test_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm_is_enabled(pwm))
return;
/*
* If the PWM channel is disabled, write value to duty and period
{
struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip);
- if (test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (pwm_is_enabled(pwm)) {
/*
* If the PWM channel is enabled, using the duty update register
* to update the value.
return container_of(_chip, struct kona_pwmc, chip);
}
-static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan)
+/*
+ * Clear trigger bit but set smooth bit to maintain old output.
+ */
+static void kona_pwmc_prepare_for_settings(struct kona_pwmc *kp,
+ unsigned int chan)
{
unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET);
- /* Clear trigger bit but set smooth bit to maintain old output */
value |= 1 << PWM_CONTROL_SMOOTH_SHIFT(chan);
value &= ~(1 << PWM_CONTROL_TRIGGER_SHIFT(chan));
writel(value, kp->base + PWM_CONTROL_OFFSET);
+ /*
+ * There must be a min 400ns delay between clearing trigger and setting
+ * it. Failing to do this may result in no PWM signal.
+ */
+ ndelay(400);
+}
+
+static void kona_pwmc_apply_settings(struct kona_pwmc *kp, unsigned int chan)
+{
+ unsigned int value = readl(kp->base + PWM_CONTROL_OFFSET);
+
/* Set trigger bit and clear smooth bit to apply new settings */
value &= ~(1 << PWM_CONTROL_SMOOTH_SHIFT(chan));
value |= 1 << PWM_CONTROL_TRIGGER_SHIFT(chan);
writel(value, kp->base + PWM_CONTROL_OFFSET);
+
+ /* Trigger bit must be held high for at least 400 ns. */
+ ndelay(400);
}
static int kona_pwmc_config(struct pwm_chip *chip, struct pwm_device *pwm,
return -EINVAL;
}
- /* If the PWM channel is enabled, write the settings to the HW */
- if (test_bit(PWMF_ENABLED, &pwm->flags)) {
+ /*
+ * Don't apply settings if disabled. The period and duty cycle are
+ * always calculated above to ensure the new values are
+ * validated immediately instead of on enable.
+ */
+ if (pwm_is_enabled(pwm)) {
+ kona_pwmc_prepare_for_settings(kp, chan);
+
value = readl(kp->base + PRESCALE_OFFSET);
value &= ~PRESCALE_MASK(chan);
value |= prescale << PRESCALE_SHIFT(chan);
return ret;
}
+ kona_pwmc_prepare_for_settings(kp, chan);
+
value = readl(kp->base + PWM_CONTROL_OFFSET);
if (polarity == PWM_POLARITY_NORMAL)
kona_pwmc_apply_settings(kp, chan);
- /* Wait for waveform to settle before gating off the clock */
- ndelay(400);
-
clk_disable_unprepare(kp->clk);
return 0;
return ret;
}
- ret = kona_pwmc_config(chip, pwm, pwm->duty_cycle, pwm->period);
+ ret = kona_pwmc_config(chip, pwm, pwm_get_duty_cycle(pwm),
+ pwm_get_period(pwm));
if (ret < 0) {
clk_disable_unprepare(kp->clk);
return ret;
{
struct kona_pwmc *kp = to_kona_pwmc(chip);
unsigned int chan = pwm->hwpwm;
+ unsigned int value;
+
+ kona_pwmc_prepare_for_settings(kp, chan);
/* Simulate a disable by configuring for zero duty */
writel(0, kp->base + DUTY_CYCLE_HIGH_OFFSET(chan));
- kona_pwmc_apply_settings(kp, chan);
+ writel(0, kp->base + PERIOD_COUNT_OFFSET(chan));
- /* Wait for waveform to settle before gating off the clock */
- ndelay(400);
+ /* Set prescale to 0 for this channel */
+ value = readl(kp->base + PRESCALE_OFFSET);
+ value &= ~PRESCALE_MASK(chan);
+ writel(value, kp->base + PRESCALE_OFFSET);
+
+ kona_pwmc_apply_settings(kp, chan);
clk_disable_unprepare(kp->clk);
}
unsigned int chan;
for (chan = 0; chan < kp->chip.npwm; chan++)
- if (test_bit(PWMF_ENABLED, &kp->chip.pwms[chan].flags))
+ if (pwm_is_enabled(&kp->chip.pwms[chan]))
clk_disable_unprepare(kp->clk);
return pwmchip_remove(&kp->chip);
* The clock needs to be enabled to access the PWM registers.
* Configuration can be changed at any time.
*/
- if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (!pwm_is_enabled(pwm)) {
ret = clk_enable(ep93xx_pwm->clk);
if (ret)
return ret;
ret = -EINVAL;
}
- if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ if (!pwm_is_enabled(pwm))
clk_disable(ep93xx_pwm->clk);
return ret;
unsigned long long c;
unsigned long period_cycles, duty_cycles, prescale;
unsigned int period_ms;
- bool enable = test_bit(PWMF_ENABLED, &pwm->flags);
+ bool enable = pwm_is_enabled(pwm);
int wait_count = 0, fifoav;
u32 cr, sr;
sr = readl(imx->mmio_base + MX3_PWMSR);
fifoav = sr & MX3_PWMSR_FIFOAV_MASK;
if (fifoav == MX3_PWMSR_FIFOAV_4WORDS) {
- period_ms = DIV_ROUND_UP(pwm->period, NSEC_PER_MSEC);
+ period_ms = DIV_ROUND_UP(pwm_get_period(pwm),
+ NSEC_PER_MSEC);
msleep(period_ms);
sr = readl(imx->mmio_base + MX3_PWMSR);
--- /dev/null
+/*
+ * NXP LPC18xx State Configurable Timer - Pulse Width Modulator driver
+ *
+ * Copyright (c) 2015 Ariel D'Alessandro <ariel@vanguardiasur.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License.
+ *
+ * Notes
+ * =====
+ * NXP LPC18xx provides a State Configurable Timer (SCT) which can be configured
+ * as a Pulse Width Modulator.
+ *
+ * SCT supports 16 outputs, 16 events and 16 registers. Each event will be
+ * triggered when its related register matches the SCT counter value, and it
+ * will set or clear a selected output.
+ *
+ * One of the events is preselected to generate the period, thus the maximum
+ * number of simultaneous channels is limited to 15. Notice that period is
+ * global to all the channels, thus PWM driver will refuse setting different
+ * values to it, unless there's only one channel requested.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+
+/* LPC18xx SCT registers */
+#define LPC18XX_PWM_CONFIG 0x000
+#define LPC18XX_PWM_CONFIG_UNIFY BIT(0)
+#define LPC18XX_PWM_CONFIG_NORELOAD BIT(7)
+
+#define LPC18XX_PWM_CTRL 0x004
+#define LPC18XX_PWM_CTRL_HALT BIT(2)
+#define LPC18XX_PWM_BIDIR BIT(4)
+#define LPC18XX_PWM_PRE_SHIFT 5
+#define LPC18XX_PWM_PRE_MASK (0xff << LPC18XX_PWM_PRE_SHIFT)
+#define LPC18XX_PWM_PRE(x) (x << LPC18XX_PWM_PRE_SHIFT)
+
+#define LPC18XX_PWM_LIMIT 0x008
+
+#define LPC18XX_PWM_RES_BASE 0x058
+#define LPC18XX_PWM_RES_SHIFT(_ch) (_ch * 2)
+#define LPC18XX_PWM_RES(_ch, _action) (_action << LPC18XX_PWM_RES_SHIFT(_ch))
+#define LPC18XX_PWM_RES_MASK(_ch) (0x3 << LPC18XX_PWM_RES_SHIFT(_ch))
+
+#define LPC18XX_PWM_MATCH_BASE 0x100
+#define LPC18XX_PWM_MATCH(_ch) (LPC18XX_PWM_MATCH_BASE + _ch * 4)
+
+#define LPC18XX_PWM_MATCHREL_BASE 0x200
+#define LPC18XX_PWM_MATCHREL(_ch) (LPC18XX_PWM_MATCHREL_BASE + _ch * 4)
+
+#define LPC18XX_PWM_EVSTATEMSK_BASE 0x300
+#define LPC18XX_PWM_EVSTATEMSK(_ch) (LPC18XX_PWM_EVSTATEMSK_BASE + _ch * 8)
+#define LPC18XX_PWM_EVSTATEMSK_ALL 0xffffffff
+
+#define LPC18XX_PWM_EVCTRL_BASE 0x304
+#define LPC18XX_PWM_EVCTRL(_ev) (LPC18XX_PWM_EVCTRL_BASE + _ev * 8)
+
+#define LPC18XX_PWM_EVCTRL_MATCH(_ch) _ch
+
+#define LPC18XX_PWM_EVCTRL_COMB_SHIFT 12
+#define LPC18XX_PWM_EVCTRL_COMB_MATCH (0x1 << LPC18XX_PWM_EVCTRL_COMB_SHIFT)
+
+#define LPC18XX_PWM_OUTPUTSET_BASE 0x500
+#define LPC18XX_PWM_OUTPUTSET(_ch) (LPC18XX_PWM_OUTPUTSET_BASE + _ch * 8)
+
+#define LPC18XX_PWM_OUTPUTCL_BASE 0x504
+#define LPC18XX_PWM_OUTPUTCL(_ch) (LPC18XX_PWM_OUTPUTCL_BASE + _ch * 8)
+
+/* LPC18xx SCT unified counter */
+#define LPC18XX_PWM_TIMER_MAX 0xffffffff
+
+/* LPC18xx SCT events */
+#define LPC18XX_PWM_EVENT_PERIOD 0
+#define LPC18XX_PWM_EVENT_MAX 16
+
+/* SCT conflict resolution */
+enum lpc18xx_pwm_res_action {
+ LPC18XX_PWM_RES_NONE,
+ LPC18XX_PWM_RES_SET,
+ LPC18XX_PWM_RES_CLEAR,
+ LPC18XX_PWM_RES_TOGGLE,
+};
+
+struct lpc18xx_pwm_data {
+ unsigned int duty_event;
+};
+
+struct lpc18xx_pwm_chip {
+ struct device *dev;
+ struct pwm_chip chip;
+ void __iomem *base;
+ struct clk *pwm_clk;
+ unsigned long clk_rate;
+ unsigned int period_ns;
+ unsigned int min_period_ns;
+ unsigned int max_period_ns;
+ unsigned int period_event;
+ unsigned long event_map;
+ struct mutex res_lock;
+ struct mutex period_lock;
+};
+
+static inline struct lpc18xx_pwm_chip *
+to_lpc18xx_pwm_chip(struct pwm_chip *chip)
+{
+ return container_of(chip, struct lpc18xx_pwm_chip, chip);
+}
+
+static inline void lpc18xx_pwm_writel(struct lpc18xx_pwm_chip *lpc18xx_pwm,
+ u32 reg, u32 val)
+{
+ writel(val, lpc18xx_pwm->base + reg);
+}
+
+static inline u32 lpc18xx_pwm_readl(struct lpc18xx_pwm_chip *lpc18xx_pwm,
+ u32 reg)
+{
+ return readl(lpc18xx_pwm->base + reg);
+}
+
+static void lpc18xx_pwm_set_conflict_res(struct lpc18xx_pwm_chip *lpc18xx_pwm,
+ struct pwm_device *pwm,
+ enum lpc18xx_pwm_res_action action)
+{
+ u32 val;
+
+ mutex_lock(&lpc18xx_pwm->res_lock);
+
+ /*
+ * Simultaneous set and clear may happen on an output, that is the case
+ * when duty_ns == period_ns. LPC18xx SCT allows to set a conflict
+ * resolution action to be taken in such a case.
+ */
+ val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_RES_BASE);
+ val &= ~LPC18XX_PWM_RES_MASK(pwm->hwpwm);
+ val |= LPC18XX_PWM_RES(pwm->hwpwm, action);
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_RES_BASE, val);
+
+ mutex_unlock(&lpc18xx_pwm->res_lock);
+}
+
+static void lpc18xx_pwm_config_period(struct pwm_chip *chip, int period_ns)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
+ u64 val;
+
+ val = (u64)period_ns * lpc18xx_pwm->clk_rate;
+ do_div(val, NSEC_PER_SEC);
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_MATCH(lpc18xx_pwm->period_event),
+ (u32)val - 1);
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_MATCHREL(lpc18xx_pwm->period_event),
+ (u32)val - 1);
+}
+
+static void lpc18xx_pwm_config_duty(struct pwm_chip *chip,
+ struct pwm_device *pwm, int duty_ns)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
+ struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+ u64 val;
+
+ val = (u64)duty_ns * lpc18xx_pwm->clk_rate;
+ do_div(val, NSEC_PER_SEC);
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_MATCH(lpc18xx_data->duty_event),
+ (u32)val);
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_MATCHREL(lpc18xx_data->duty_event),
+ (u32)val);
+}
+
+static int lpc18xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
+ int requested_events, i;
+
+ if (period_ns < lpc18xx_pwm->min_period_ns ||
+ period_ns > lpc18xx_pwm->max_period_ns) {
+ dev_err(chip->dev, "period %d not in range\n", period_ns);
+ return -ERANGE;
+ }
+
+ mutex_lock(&lpc18xx_pwm->period_lock);
+
+ requested_events = bitmap_weight(&lpc18xx_pwm->event_map,
+ LPC18XX_PWM_EVENT_MAX);
+
+ /*
+ * The PWM supports only a single period for all PWM channels.
+ * Once the period is set, it can only be changed if no more than one
+ * channel is requested at that moment.
+ */
+ if (requested_events > 2 && lpc18xx_pwm->period_ns != period_ns &&
+ lpc18xx_pwm->period_ns) {
+ dev_err(chip->dev, "conflicting period requested for PWM %u\n",
+ pwm->hwpwm);
+ mutex_unlock(&lpc18xx_pwm->period_lock);
+ return -EBUSY;
+ }
+
+ if ((requested_events <= 2 && lpc18xx_pwm->period_ns != period_ns) ||
+ !lpc18xx_pwm->period_ns) {
+ lpc18xx_pwm->period_ns = period_ns;
+ for (i = 0; i < chip->npwm; i++)
+ pwm_set_period(&chip->pwms[i], period_ns);
+ lpc18xx_pwm_config_period(chip, period_ns);
+ }
+
+ mutex_unlock(&lpc18xx_pwm->period_lock);
+
+ lpc18xx_pwm_config_duty(chip, pwm, duty_ns);
+
+ return 0;
+}
+
+static int lpc18xx_pwm_set_polarity(struct pwm_chip *chip,
+ struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ return 0;
+}
+
+static int lpc18xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
+ struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+ enum lpc18xx_pwm_res_action res_action;
+ unsigned int set_event, clear_event;
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event),
+ LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_data->duty_event) |
+ LPC18XX_PWM_EVCTRL_COMB_MATCH);
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_EVSTATEMSK(lpc18xx_data->duty_event),
+ LPC18XX_PWM_EVSTATEMSK_ALL);
+
+ if (pwm->polarity == PWM_POLARITY_NORMAL) {
+ set_event = lpc18xx_pwm->period_event;
+ clear_event = lpc18xx_data->duty_event;
+ res_action = LPC18XX_PWM_RES_SET;
+ } else {
+ set_event = lpc18xx_data->duty_event;
+ clear_event = lpc18xx_pwm->period_event;
+ res_action = LPC18XX_PWM_RES_CLEAR;
+ }
+
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm),
+ BIT(set_event));
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm),
+ BIT(clear_event));
+ lpc18xx_pwm_set_conflict_res(lpc18xx_pwm, pwm, res_action);
+
+ return 0;
+}
+
+static void lpc18xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
+ struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_EVCTRL(lpc18xx_data->duty_event), 0);
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTSET(pwm->hwpwm), 0);
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_OUTPUTCL(pwm->hwpwm), 0);
+}
+
+static int lpc18xx_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
+ struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+ unsigned long event;
+
+ event = find_first_zero_bit(&lpc18xx_pwm->event_map,
+ LPC18XX_PWM_EVENT_MAX);
+
+ if (event >= LPC18XX_PWM_EVENT_MAX) {
+ dev_err(lpc18xx_pwm->dev,
+ "maximum number of simultaneous channels reached\n");
+ return -EBUSY;
+ };
+
+ set_bit(event, &lpc18xx_pwm->event_map);
+ lpc18xx_data->duty_event = event;
+ lpc18xx_pwm_config_duty(chip, pwm, pwm_get_duty_cycle(pwm));
+
+ return 0;
+}
+
+static void lpc18xx_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = to_lpc18xx_pwm_chip(chip);
+ struct lpc18xx_pwm_data *lpc18xx_data = pwm_get_chip_data(pwm);
+
+ pwm_disable(pwm);
+ pwm_set_duty_cycle(pwm, 0);
+ clear_bit(lpc18xx_data->duty_event, &lpc18xx_pwm->event_map);
+}
+
+static const struct pwm_ops lpc18xx_pwm_ops = {
+ .config = lpc18xx_pwm_config,
+ .set_polarity = lpc18xx_pwm_set_polarity,
+ .enable = lpc18xx_pwm_enable,
+ .disable = lpc18xx_pwm_disable,
+ .request = lpc18xx_pwm_request,
+ .free = lpc18xx_pwm_free,
+ .owner = THIS_MODULE,
+};
+
+static const struct of_device_id lpc18xx_pwm_of_match[] = {
+ { .compatible = "nxp,lpc1850-sct-pwm" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, lpc18xx_pwm_of_match);
+
+static int lpc18xx_pwm_probe(struct platform_device *pdev)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm;
+ struct pwm_device *pwm;
+ struct resource *res;
+ int ret, i;
+ u64 val;
+
+ lpc18xx_pwm = devm_kzalloc(&pdev->dev, sizeof(*lpc18xx_pwm),
+ GFP_KERNEL);
+ if (!lpc18xx_pwm)
+ return -ENOMEM;
+
+ lpc18xx_pwm->dev = &pdev->dev;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ lpc18xx_pwm->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(lpc18xx_pwm->base))
+ return PTR_ERR(lpc18xx_pwm->base);
+
+ lpc18xx_pwm->pwm_clk = devm_clk_get(&pdev->dev, "pwm");
+ if (IS_ERR(lpc18xx_pwm->pwm_clk)) {
+ dev_err(&pdev->dev, "failed to get pwm clock\n");
+ return PTR_ERR(lpc18xx_pwm->pwm_clk);
+ }
+
+ ret = clk_prepare_enable(lpc18xx_pwm->pwm_clk);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "could not prepare or enable pwm clock\n");
+ return ret;
+ }
+
+ lpc18xx_pwm->clk_rate = clk_get_rate(lpc18xx_pwm->pwm_clk);
+
+ mutex_init(&lpc18xx_pwm->res_lock);
+ mutex_init(&lpc18xx_pwm->period_lock);
+
+ val = (u64)NSEC_PER_SEC * LPC18XX_PWM_TIMER_MAX;
+ do_div(val, lpc18xx_pwm->clk_rate);
+ lpc18xx_pwm->max_period_ns = val;
+
+ lpc18xx_pwm->min_period_ns = DIV_ROUND_UP(NSEC_PER_SEC,
+ lpc18xx_pwm->clk_rate);
+
+ lpc18xx_pwm->chip.dev = &pdev->dev;
+ lpc18xx_pwm->chip.ops = &lpc18xx_pwm_ops;
+ lpc18xx_pwm->chip.base = -1;
+ lpc18xx_pwm->chip.npwm = 16;
+ lpc18xx_pwm->chip.of_xlate = of_pwm_xlate_with_flags;
+ lpc18xx_pwm->chip.of_pwm_n_cells = 3;
+
+ /* SCT counter must be in unify (32 bit) mode */
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CONFIG,
+ LPC18XX_PWM_CONFIG_UNIFY);
+
+ /*
+ * Everytime the timer counter reaches the period value, the related
+ * event will be triggered and the counter reset to 0.
+ */
+ set_bit(LPC18XX_PWM_EVENT_PERIOD, &lpc18xx_pwm->event_map);
+ lpc18xx_pwm->period_event = LPC18XX_PWM_EVENT_PERIOD;
+
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_EVSTATEMSK(lpc18xx_pwm->period_event),
+ LPC18XX_PWM_EVSTATEMSK_ALL);
+
+ val = LPC18XX_PWM_EVCTRL_MATCH(lpc18xx_pwm->period_event) |
+ LPC18XX_PWM_EVCTRL_COMB_MATCH;
+ lpc18xx_pwm_writel(lpc18xx_pwm,
+ LPC18XX_PWM_EVCTRL(lpc18xx_pwm->period_event), val);
+
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_LIMIT,
+ BIT(lpc18xx_pwm->period_event));
+
+ ret = pwmchip_add(&lpc18xx_pwm->chip);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pwmchip_add failed: %d\n", ret);
+ goto disable_pwmclk;
+ }
+
+ for (i = 0; i < lpc18xx_pwm->chip.npwm; i++) {
+ pwm = &lpc18xx_pwm->chip.pwms[i];
+ pwm->chip_data = devm_kzalloc(lpc18xx_pwm->dev,
+ sizeof(struct lpc18xx_pwm_data),
+ GFP_KERNEL);
+ if (!pwm->chip_data) {
+ ret = -ENOMEM;
+ goto remove_pwmchip;
+ }
+ }
+
+ platform_set_drvdata(pdev, lpc18xx_pwm);
+
+ val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
+ val &= ~LPC18XX_PWM_BIDIR;
+ val &= ~LPC18XX_PWM_CTRL_HALT;
+ val &= ~LPC18XX_PWM_PRE_MASK;
+ val |= LPC18XX_PWM_PRE(0);
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL, val);
+
+ return 0;
+
+remove_pwmchip:
+ pwmchip_remove(&lpc18xx_pwm->chip);
+disable_pwmclk:
+ clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
+ return ret;
+}
+
+static int lpc18xx_pwm_remove(struct platform_device *pdev)
+{
+ struct lpc18xx_pwm_chip *lpc18xx_pwm = platform_get_drvdata(pdev);
+ u32 val;
+
+ val = lpc18xx_pwm_readl(lpc18xx_pwm, LPC18XX_PWM_CTRL);
+ lpc18xx_pwm_writel(lpc18xx_pwm, LPC18XX_PWM_CTRL,
+ val | LPC18XX_PWM_CTRL_HALT);
+
+ clk_disable_unprepare(lpc18xx_pwm->pwm_clk);
+
+ return pwmchip_remove(&lpc18xx_pwm->chip);
+}
+
+static struct platform_driver lpc18xx_pwm_driver = {
+ .driver = {
+ .name = "lpc18xx-sct-pwm",
+ .of_match_table = lpc18xx_pwm_of_match,
+ },
+ .probe = lpc18xx_pwm_probe,
+ .remove = lpc18xx_pwm_remove,
+};
+module_platform_driver(lpc18xx_pwm_driver);
+
+MODULE_AUTHOR("Ariel D'Alessandro <ariel@vanguardiasur.com.ar>");
+MODULE_DESCRIPTION("NXP LPC18xx PWM driver");
+MODULE_LICENSE("GPL v2");
* If the PWM channel is disabled, make sure to turn on the clock
* before writing the register. Otherwise, keep it enabled.
*/
- if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (!pwm_is_enabled(pwm)) {
ret = clk_prepare_enable(mxs->clk);
if (ret)
return ret;
/*
* If the PWM is not enabled, turn the clock off again to save power.
*/
- if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ if (!pwm_is_enabled(pwm))
clk_disable_unprepare(mxs->clk);
return 0;
* Driver for PCA9685 16-channel 12-bit PWM LED controller
*
* Copyright (C) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
+ * Copyright (C) 2015 Clemens Gruber <clemens.gruber@pqgruber.com>
*
* based on the pwm-twl-led.c driver
*
#include <linux/pwm.h>
#include <linux/regmap.h>
#include <linux/slab.h>
+#include <linux/delay.h>
+
+/*
+ * Because the PCA9685 has only one prescaler per chip, changing the period of
+ * one channel affects the period of all 16 PWM outputs!
+ * However, the ratio between each configured duty cycle and the chip-wide
+ * period remains constant, because the OFF time is set in proportion to the
+ * counter range.
+ */
#define PCA9685_MODE1 0x00
#define PCA9685_MODE2 0x01
#define PCA9685_ALL_LED_OFF_H 0xFD
#define PCA9685_PRESCALE 0xFE
+#define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */
+#define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */
+
+#define PCA9685_COUNTER_RANGE 4096
+#define PCA9685_DEFAULT_PERIOD 5000000 /* Default period_ns = 1/200 Hz */
+#define PCA9685_OSC_CLOCK_MHZ 25 /* Internal oscillator with 25 MHz */
+
#define PCA9685_NUMREGS 0xFF
#define PCA9685_MAXCHAN 0x10
#define LED_FULL (1 << 4)
+#define MODE1_RESTART (1 << 7)
#define MODE1_SLEEP (1 << 4)
#define MODE2_INVRT (1 << 4)
#define MODE2_OUTDRV (1 << 2)
struct pwm_chip chip;
struct regmap *regmap;
int active_cnt;
+ int duty_ns;
+ int period_ns;
};
static inline struct pca9685 *to_pca(struct pwm_chip *chip)
struct pca9685 *pca = to_pca(chip);
unsigned long long duty;
unsigned int reg;
+ int prescale;
+
+ if (period_ns != pca->period_ns) {
+ prescale = DIV_ROUND_CLOSEST(PCA9685_OSC_CLOCK_MHZ * period_ns,
+ PCA9685_COUNTER_RANGE * 1000) - 1;
+
+ if (prescale >= PCA9685_PRESCALE_MIN &&
+ prescale <= PCA9685_PRESCALE_MAX) {
+ /* Put chip into sleep mode */
+ regmap_update_bits(pca->regmap, PCA9685_MODE1,
+ MODE1_SLEEP, MODE1_SLEEP);
+
+ /* Change the chip-wide output frequency */
+ regmap_write(pca->regmap, PCA9685_PRESCALE, prescale);
+
+ /* Wake the chip up */
+ regmap_update_bits(pca->regmap, PCA9685_MODE1,
+ MODE1_SLEEP, 0x0);
+
+ /* Wait 500us for the oscillator to be back up */
+ udelay(500);
+
+ pca->period_ns = period_ns;
+
+ /*
+ * If the duty cycle did not change, restart PWM with
+ * the same duty cycle to period ratio and return.
+ */
+ if (duty_ns == pca->duty_ns) {
+ regmap_update_bits(pca->regmap, PCA9685_MODE1,
+ MODE1_RESTART, 0x1);
+ return 0;
+ }
+ } else {
+ dev_err(chip->dev,
+ "prescaler not set: period out of bounds!\n");
+ return -EINVAL;
+ }
+ }
+
+ pca->duty_ns = duty_ns;
if (duty_ns < 1) {
if (pwm->hwpwm >= PCA9685_MAXCHAN)
}
if (duty_ns == period_ns) {
+ /* Clear both OFF registers */
+ if (pwm->hwpwm >= PCA9685_MAXCHAN)
+ reg = PCA9685_ALL_LED_OFF_L;
+ else
+ reg = LED_N_OFF_L(pwm->hwpwm);
+
+ regmap_write(pca->regmap, reg, 0x0);
+
+ if (pwm->hwpwm >= PCA9685_MAXCHAN)
+ reg = PCA9685_ALL_LED_OFF_H;
+ else
+ reg = LED_N_OFF_H(pwm->hwpwm);
+
+ regmap_write(pca->regmap, reg, 0x0);
+
+ /* Set the full ON bit */
if (pwm->hwpwm >= PCA9685_MAXCHAN)
reg = PCA9685_ALL_LED_ON_H;
else
return 0;
}
- duty = 4096 * (unsigned long long)duty_ns;
+ duty = PCA9685_COUNTER_RANGE * (unsigned long long)duty_ns;
duty = DIV_ROUND_UP_ULL(duty, period_ns);
if (pwm->hwpwm >= PCA9685_MAXCHAN)
regmap_write(pca->regmap, reg, ((int)duty >> 8) & 0xf);
+ /* Clear the full ON bit, otherwise the set OFF time has no effect */
+ if (pwm->hwpwm >= PCA9685_MAXCHAN)
+ reg = PCA9685_ALL_LED_ON_H;
+ else
+ reg = LED_N_ON_H(pwm->hwpwm);
+
+ regmap_write(pca->regmap, reg, 0);
+
return 0;
}
ret);
return ret;
}
+ pca->duty_ns = 0;
+ pca->period_ns = PCA9685_DEFAULT_PERIOD;
i2c_set_clientdata(client, pca);
static struct i2c_driver pca9685_i2c_driver = {
.driver = {
.name = "pca9685-pwm",
- .owner = THIS_MODULE,
.of_match_table = pca9685_dt_ids,
},
.probe = pca9685_pwm_probe,
pwm->duty = duty;
/* If the channel is disabled we're done. */
- if (!test_bit(PWMF_ENABLED, &_pwm->flags))
+ if (!pwm_is_enabled(_pwm))
return 0;
if (duty_only && pwm->timer_on) {
PWM_CONTINUOUS;
u32 val;
- if (pwm->polarity == PWM_POLARITY_INVERSED)
+ if (pwm_get_polarity(pwm) == PWM_POLARITY_INVERSED)
enable_conf |= PWM_DUTY_NEGATIVE | PWM_INACTIVE_POSITIVE;
else
enable_conf |= PWM_DUTY_POSITIVE | PWM_INACTIVE_NEGATIVE;
* If the PWM channel is disabled, make sure to turn on the clock
* before writing the register. Otherwise, keep it enabled.
*/
- if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (!pwm_is_enabled(pwm)) {
err = clk_prepare_enable(pc->clk);
if (err < 0)
return err;
/*
* If the PWM is not enabled, turn the clock off again to save power.
*/
- if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ if (!pwm_is_enabled(pwm))
clk_disable_unprepare(pc->clk);
return 0;
for (i = 0; i < NUM_PWM; i++) {
struct pwm_device *pwm = &pc->chip.pwms[i];
- if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ if (!pwm_is_enabled(pwm))
if (clk_prepare_enable(pc->clk) < 0)
continue;
writew(reg_val, pc->mmio_base + ECCTL2);
- if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (!pwm_is_enabled(pwm)) {
/* Update active registers if not running */
writel(duty_cycles, pc->mmio_base + CAP2);
writel(period_cycles, pc->mmio_base + CAP1);
writel(period_cycles, pc->mmio_base + CAP3);
}
- if (!test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (!pwm_is_enabled(pwm)) {
reg_val = readw(pc->mmio_base + ECCTL2);
/* Disable APWM mode to put APWM output Low */
reg_val &= ~ECCTL2_APWM_MODE;
static void ecap_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
{
- if (test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (pwm_is_enabled(pwm)) {
dev_warn(chip->dev, "Removing PWM device without disabling\n");
pm_runtime_put_sync(chip->dev);
}
ecap_pwm_save_context(pc);
/* Disable explicitly if PWM is running */
- if (test_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm_is_enabled(pwm))
pm_runtime_put_sync(dev);
return 0;
struct pwm_device *pwm = pc->chip.pwms;
/* Enable explicitly if PWM was running */
- if (test_bit(PWMF_ENABLED, &pwm->flags))
+ if (pwm_is_enabled(pwm))
pm_runtime_get_sync(dev);
ecap_pwm_restore_context(pc);
{
struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
- if (test_bit(PWMF_ENABLED, &pwm->flags)) {
+ if (pwm_is_enabled(pwm)) {
dev_warn(chip->dev, "Removing PWM device without disabling\n");
pm_runtime_put_sync(chip->dev);
}
for (i = 0; i < pc->chip.npwm; i++) {
struct pwm_device *pwm = &pc->chip.pwms[i];
- if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ if (!pwm_is_enabled(pwm))
continue;
/* Disable explicitly if PWM is running */
for (i = 0; i < pc->chip.npwm; i++) {
struct pwm_device *pwm = &pc->chip.pwms[i];
- if (!test_bit(PWMF_ENABLED, &pwm->flags))
+ if (!pwm_is_enabled(pwm))
continue;
/* Enable explicitly if PWM was running */
{
const struct pwm_device *pwm = child_to_pwm_device(child);
- return sprintf(buf, "%u\n", pwm->period);
+ return sprintf(buf, "%u\n", pwm_get_period(pwm));
}
static ssize_t pwm_period_store(struct device *child,
if (ret)
return ret;
- ret = pwm_config(pwm, pwm->duty_cycle, val);
+ ret = pwm_config(pwm, pwm_get_duty_cycle(pwm), val);
return ret ? : size;
}
{
const struct pwm_device *pwm = child_to_pwm_device(child);
- return sprintf(buf, "%u\n", pwm->duty_cycle);
+ return sprintf(buf, "%u\n", pwm_get_duty_cycle(pwm));
}
static ssize_t pwm_duty_cycle_store(struct device *child,
if (ret)
return ret;
- ret = pwm_config(pwm, val, pwm->period);
+ ret = pwm_config(pwm, val, pwm_get_period(pwm));
return ret ? : size;
}
char *buf)
{
const struct pwm_device *pwm = child_to_pwm_device(child);
- int enabled = test_bit(PWMF_ENABLED, &pwm->flags);
+ int enabled = pwm_is_enabled(pwm);
return sprintf(buf, "%d\n", enabled);
}
char *buf)
{
const struct pwm_device *pwm = child_to_pwm_device(child);
+ const char *polarity = "unknown";
- return sprintf(buf, "%s\n", pwm->polarity ? "inversed" : "normal");
+ switch (pwm_get_polarity(pwm)) {
+ case PWM_POLARITY_NORMAL:
+ polarity = "normal";
+ break;
+
+ case PWM_POLARITY_INVERSED:
+ polarity = "inversed";
+ break;
+ }
+
+ return sprintf(buf, "%s\n", polarity);
}
static ssize_t pwm_polarity_store(struct device *child,
ATTRIBUTE_GROUPS(pwm_chip);
static struct class pwm_class = {
- .name = "pwm",
- .owner = THIS_MODULE,
- .dev_groups = pwm_chip_groups,
+ .name = "pwm",
+ .owner = THIS_MODULE,
+ .dev_groups = pwm_chip_groups,
};
static int pwmchip_sysfs_match(struct device *parent, const void *data)
PWMF_EXPORTED = 1 << 2,
};
+/**
+ * struct pwm_device - PWM channel object
+ * @label: name of the PWM device
+ * @flags: flags associated with the PWM device
+ * @hwpwm: per-chip relative index of the PWM device
+ * @pwm: global index of the PWM device
+ * @chip: PWM chip providing this PWM device
+ * @chip_data: chip-private data associated with the PWM device
+ * @period: period of the PWM signal (in nanoseconds)
+ * @duty_cycle: duty cycle of the PWM signal (in nanoseconds)
+ * @polarity: polarity of the PWM signal
+ */
struct pwm_device {
- const char *label;
- unsigned long flags;
- unsigned int hwpwm;
- unsigned int pwm;
- struct pwm_chip *chip;
- void *chip_data;
-
- unsigned int period; /* in nanoseconds */
- unsigned int duty_cycle; /* in nanoseconds */
- enum pwm_polarity polarity;
+ const char *label;
+ unsigned long flags;
+ unsigned int hwpwm;
+ unsigned int pwm;
+ struct pwm_chip *chip;
+ void *chip_data;
+
+ unsigned int period;
+ unsigned int duty_cycle;
+ enum pwm_polarity polarity;
};
+static inline bool pwm_is_enabled(const struct pwm_device *pwm)
+{
+ return test_bit(PWMF_ENABLED, &pwm->flags);
+}
+
static inline void pwm_set_period(struct pwm_device *pwm, unsigned int period)
{
if (pwm)
pwm->period = period;
}
-static inline unsigned int pwm_get_period(struct pwm_device *pwm)
+static inline unsigned int pwm_get_period(const struct pwm_device *pwm)
{
return pwm ? pwm->period : 0;
}
pwm->duty_cycle = duty;
}
-static inline unsigned int pwm_get_duty_cycle(struct pwm_device *pwm)
+static inline unsigned int pwm_get_duty_cycle(const struct pwm_device *pwm)
{
return pwm ? pwm->duty_cycle : 0;
}
*/
int pwm_set_polarity(struct pwm_device *pwm, enum pwm_polarity polarity);
+static inline enum pwm_polarity pwm_get_polarity(const struct pwm_device *pwm)
+{
+ return pwm ? pwm->polarity : PWM_POLARITY_NORMAL;
+}
+
/**
* struct pwm_ops - PWM controller operations
* @request: optional hook for requesting a PWM
* @owner: helps prevent removal of modules exporting active PWMs
*/
struct pwm_ops {
- int (*request)(struct pwm_chip *chip,
- struct pwm_device *pwm);
- void (*free)(struct pwm_chip *chip,
- struct pwm_device *pwm);
- int (*config)(struct pwm_chip *chip,
- struct pwm_device *pwm,
- int duty_ns, int period_ns);
- int (*set_polarity)(struct pwm_chip *chip,
- struct pwm_device *pwm,
- enum pwm_polarity polarity);
- int (*enable)(struct pwm_chip *chip,
- struct pwm_device *pwm);
- void (*disable)(struct pwm_chip *chip,
- struct pwm_device *pwm);
+ int (*request)(struct pwm_chip *chip, struct pwm_device *pwm);
+ void (*free)(struct pwm_chip *chip, struct pwm_device *pwm);
+ int (*config)(struct pwm_chip *chip, struct pwm_device *pwm,
+ int duty_ns, int period_ns);
+ int (*set_polarity)(struct pwm_chip *chip, struct pwm_device *pwm,
+ enum pwm_polarity polarity);
+ int (*enable)(struct pwm_chip *chip, struct pwm_device *pwm);
+ void (*disable)(struct pwm_chip *chip, struct pwm_device *pwm);
#ifdef CONFIG_DEBUG_FS
- void (*dbg_show)(struct pwm_chip *chip,
- struct seq_file *s);
+ void (*dbg_show)(struct pwm_chip *chip, struct seq_file *s);
#endif
- struct module *owner;
+ struct module *owner;
};
/**
* @base: number of first PWM controlled by this chip
* @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
+ * @of_pwm_n_cells: number of cells expected in the device tree PWM specifier
* @can_sleep: must be true if the .config(), .enable() or .disable()
* operations may sleep
*/
struct pwm_chip {
- struct device *dev;
- struct list_head list;
- const struct pwm_ops *ops;
- int base;
- unsigned int npwm;
-
- struct pwm_device *pwms;
-
- struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
- const struct of_phandle_args *args);
- unsigned int of_pwm_n_cells;
- bool can_sleep;
+ struct device *dev;
+ struct list_head list;
+ const struct pwm_ops *ops;
+ int base;
+ unsigned int npwm;
+
+ struct pwm_device *pwms;
+
+ struct pwm_device * (*of_xlate)(struct pwm_chip *pc,
+ const struct of_phandle_args *args);
+ unsigned int of_pwm_n_cells;
+ bool can_sleep;
};
#if IS_ENABLED(CONFIG_PWM)
projects / platform / kernel / linux-rpi.git / commitdiff