diff options
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/pwm/core.c | 13 | ||||
| -rw-r--r-- | drivers/pwm/pwm-atmel.c | 87 | ||||
| -rw-r--r-- | drivers/pwm/pwm-cros-ec.c | 58 | ||||
| -rw-r--r-- | drivers/pwm/pwm-imx27.c | 147 | ||||
| -rw-r--r-- | drivers/pwm/pwm-mxs.c | 101 | ||||
| -rw-r--r-- | drivers/pwm/pwm-omap-dmtimer.c | 54 | ||||
| -rw-r--r-- | drivers/pwm/pwm-pca9685.c | 4 | ||||
| -rw-r--r-- | drivers/pwm/pwm-rcar.c | 5 | ||||
| -rw-r--r-- | drivers/pwm/pwm-stm32.c | 4 | ||||
| -rw-r--r-- | drivers/pwm/pwm-sun4i.c | 194 |
11 files changed, 479 insertions, 197 deletions
diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index bd21655c37a6..30190beeb6e9 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -100,7 +100,7 @@ config PWM_BCM_KONA config PWM_BCM2835 tristate "BCM2835 PWM support" - depends on ARCH_BCM2835 + depends on ARCH_BCM2835 || ARCH_BRCMSTB help PWM framework driver for BCM2835 controller (Raspberry Pi) @@ -328,7 +328,8 @@ config PWM_MXS config PWM_OMAP_DMTIMER tristate "OMAP Dual-Mode Timer PWM support" - depends on OF && ARCH_OMAP && OMAP_DM_TIMER + depends on OF + depends on OMAP_DM_TIMER || COMPILE_TEST help Generic PWM framework driver for OMAP Dual-Mode Timer PWM output @@ -490,7 +491,7 @@ config PWM_TEGRA To compile this driver as a module, choose M here: the module will be called pwm-tegra. -config PWM_TIECAP +config PWM_TIECAP tristate "ECAP PWM support" depends on ARCH_OMAP2PLUS || ARCH_DAVINCI_DA8XX || ARCH_KEYSTONE || ARCH_K3 help @@ -499,7 +500,7 @@ config PWM_TIECAP To compile this driver as a module, choose M here: the module will be called pwm-tiecap. -config PWM_TIEHRPWM +config PWM_TIEHRPWM tristate "EHRPWM PWM support" depends on ARCH_OMAP2PLUS || ARCH_DAVINCI_DA8XX || ARCH_K3 help diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index f877e77d9184..5a7f6598c05f 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -20,6 +20,9 @@ #include <dt-bindings/pwm/pwm.h> +#define CREATE_TRACE_POINTS +#include <trace/events/pwm.h> + #define MAX_PWMS 1024 static DEFINE_MUTEX(pwm_lookup_lock); @@ -114,6 +117,11 @@ static int pwm_device_request(struct pwm_device *pwm, const char *label) } } + if (pwm->chip->ops->get_state) { + pwm->chip->ops->get_state(pwm->chip, pwm, &pwm->state); + trace_pwm_get(pwm, &pwm->state); + } + set_bit(PWMF_REQUESTED, &pwm->flags); pwm->label = label; @@ -283,9 +291,6 @@ int pwmchip_add_with_polarity(struct pwm_chip *chip, pwm->hwpwm = i; pwm->state.polarity = polarity; - if (chip->ops->get_state) - chip->ops->get_state(chip, pwm, &pwm->state); - radix_tree_insert(&pwm_tree, pwm->pwm, pwm); } @@ -472,6 +477,8 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) if (err) return err; + trace_pwm_apply(pwm, state); + pwm->state = *state; } else { /* diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index 9ba733467e26..6161e7e3e9ac 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -4,6 +4,19 @@ * * Copyright (C) 2013 Atmel Corporation * Bo Shen <voice.shen@atmel.com> + * + * Links to reference manuals for the supported PWM chips can be found in + * Documentation/arm/microchip.rst. + * + * Limitations: + * - Periods start with the inactive level. + * - Hardware has to be stopped in general to update settings. + * + * Software bugs/possible improvements: + * - When atmel_pwm_apply() is called with state->enabled=false a change in + * state->polarity isn't honored. + * - Instead of sleeping to wait for a completed period, the interrupt + * functionality could be used. */ #include <linux/clk.h> @@ -47,6 +60,8 @@ #define PWMV2_CPRD 0x0C #define PWMV2_CPRDUPD 0x10 +#define PWM_MAX_PRES 10 + struct atmel_pwm_registers { u8 period; u8 period_upd; @@ -55,8 +70,7 @@ struct atmel_pwm_registers { }; struct atmel_pwm_config { - u32 max_period; - u32 max_pres; + u32 period_bits; }; struct atmel_pwm_data { @@ -97,7 +111,7 @@ static inline u32 atmel_pwm_ch_readl(struct atmel_pwm_chip *chip, { unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE; - return readl_relaxed(chip->base + base + offset); + return atmel_pwm_readl(chip, base + offset); } static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip, @@ -106,7 +120,7 @@ static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip, { unsigned long base = PWM_CH_REG_OFFSET + ch * PWM_CH_REG_SIZE; - writel_relaxed(val, chip->base + base + offset); + atmel_pwm_writel(chip, base + offset, val); } static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip, @@ -115,17 +129,27 @@ static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip, { struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); unsigned long long cycles = state->period; + int shift; /* Calculate the period cycles and prescale value */ cycles *= clk_get_rate(atmel_pwm->clk); do_div(cycles, NSEC_PER_SEC); - for (*pres = 0; cycles > atmel_pwm->data->cfg.max_period; cycles >>= 1) - (*pres)++; + /* + * The register for the period length is cfg.period_bits bits wide. + * So for each bit the number of clock cycles is wider divide the input + * clock frequency by two using pres and shift cprd accordingly. + */ + shift = fls(cycles) - atmel_pwm->data->cfg.period_bits; - if (*pres > atmel_pwm->data->cfg.max_pres) { + if (shift > PWM_MAX_PRES) { dev_err(chip->dev, "pres exceeds the maximum value\n"); return -EINVAL; + } else if (shift > 0) { + *pres = shift; + cycles >>= *pres; + } else { + *pres = 0; } *cprd = cycles; @@ -271,8 +295,48 @@ static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return 0; } +static void atmel_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); + u32 sr, cmr; + + sr = atmel_pwm_readl(atmel_pwm, PWM_SR); + cmr = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); + + if (sr & (1 << pwm->hwpwm)) { + unsigned long rate = clk_get_rate(atmel_pwm->clk); + u32 cdty, cprd, pres; + u64 tmp; + + pres = cmr & PWM_CMR_CPRE_MSK; + + cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, + atmel_pwm->data->regs.period); + tmp = (u64)cprd * NSEC_PER_SEC; + tmp <<= pres; + state->period = DIV64_U64_ROUND_UP(tmp, rate); + + cdty = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, + atmel_pwm->data->regs.duty); + tmp = (u64)cdty * NSEC_PER_SEC; + tmp <<= pres; + state->duty_cycle = DIV64_U64_ROUND_UP(tmp, rate); + + state->enabled = true; + } else { + state->enabled = false; + } + + if (cmr & PWM_CMR_CPOL) + state->polarity = PWM_POLARITY_INVERSED; + else + state->polarity = PWM_POLARITY_NORMAL; +} + static const struct pwm_ops atmel_pwm_ops = { .apply = atmel_pwm_apply, + .get_state = atmel_pwm_get_state, .owner = THIS_MODULE, }; @@ -285,8 +349,7 @@ static const struct atmel_pwm_data atmel_sam9rl_pwm_data = { }, .cfg = { /* 16 bits to keep period and duty. */ - .max_period = 0xffff, - .max_pres = 10, + .period_bits = 16, }, }; @@ -299,8 +362,7 @@ static const struct atmel_pwm_data atmel_sama5_pwm_data = { }, .cfg = { /* 16 bits to keep period and duty. */ - .max_period = 0xffff, - .max_pres = 10, + .period_bits = 16, }, }; @@ -313,8 +375,7 @@ static const struct atmel_pwm_data mchp_sam9x60_pwm_data = { }, .cfg = { /* 32 bits to keep period and duty. */ - .max_period = 0xffffffff, - .max_pres = 10, + .period_bits = 32, }, }; diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c index 89497448d217..09c08dee099e 100644 --- a/drivers/pwm/pwm-cros-ec.c +++ b/drivers/pwm/pwm-cros-ec.c @@ -25,11 +25,39 @@ struct cros_ec_pwm_device { struct pwm_chip chip; }; +/** + * struct cros_ec_pwm - per-PWM driver data + * @duty_cycle: cached duty cycle + */ +struct cros_ec_pwm { + u16 duty_cycle; +}; + static inline struct cros_ec_pwm_device *pwm_to_cros_ec_pwm(struct pwm_chip *c) { return container_of(c, struct cros_ec_pwm_device, chip); } +static int cros_ec_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct cros_ec_pwm *channel; + + channel = kzalloc(sizeof(*channel), GFP_KERNEL); + if (!channel) + return -ENOMEM; + + pwm_set_chip_data(pwm, channel); + + return 0; +} + +static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) +{ + struct cros_ec_pwm *channel = pwm_get_chip_data(pwm); + + kfree(channel); +} + static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty) { struct { @@ -96,7 +124,9 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip); - int duty_cycle; + struct cros_ec_pwm *channel = pwm_get_chip_data(pwm); + u16 duty_cycle; + int ret; /* The EC won't let us change the period */ if (state->period != EC_PWM_MAX_DUTY) @@ -108,13 +138,20 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, */ duty_cycle = state->enabled ? state->duty_cycle : 0; - return cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle); + ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle); + if (ret < 0) + return ret; + + channel->duty_cycle = state->duty_cycle; + + return 0; } static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { struct cros_ec_pwm_device *ec_pwm = pwm_to_cros_ec_pwm(chip); + struct cros_ec_pwm *channel = pwm_get_chip_data(pwm); int ret; ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm); @@ -126,8 +163,19 @@ static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, state->enabled = (ret > 0); state->period = EC_PWM_MAX_DUTY; - /* Note that "disabled" and "duty cycle == 0" are treated the same */ - state->duty_cycle = ret; + /* + * Note that "disabled" and "duty cycle == 0" are treated the same. If + * the cached duty cycle is not zero, used the cached duty cycle. This + * ensures that the configured duty cycle is kept across a disable and + * enable operation and avoids potentially confusing consumers. + * + * For the case of the initial hardware readout, channel->duty_cycle + * will be 0 and the actual duty cycle read from the EC is used. + */ + if (ret == 0 && channel->duty_cycle > 0) + state->duty_cycle = channel->duty_cycle; + else + state->duty_cycle = ret; } static struct pwm_device * @@ -149,6 +197,8 @@ cros_ec_pwm_xlate(struct pwm_chip *pc, const struct of_phandle_args *args) } static const struct pwm_ops cros_ec_pwm_ops = { + .request = cros_ec_pwm_request, + .free = cros_ec_pwm_free, .get_state = cros_ec_pwm_get_state, .apply = cros_ec_pwm_apply, .owner = THIS_MODULE, diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c index ae11d8577f18..35a7ac42269c 100644 --- a/drivers/pwm/pwm-imx27.c +++ b/drivers/pwm/pwm-imx27.c @@ -85,6 +85,13 @@ struct pwm_imx27_chip { struct clk *clk_per; void __iomem *mmio_base; struct pwm_chip chip; + + /* + * The driver cannot read the current duty cycle from the hardware if + * the hardware is disabled. Cache the last programmed duty cycle + * value to return in that case. + */ + unsigned int duty_cycle; }; #define to_pwm_imx27_chip(chip) container_of(chip, struct pwm_imx27_chip, chip) @@ -155,14 +162,17 @@ static void pwm_imx27_get_state(struct pwm_chip *chip, tmp = NSEC_PER_SEC * (u64)(period + 2); state->period = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk); - /* PWMSAR can be read only if PWM is enabled */ - if (state->enabled) { + /* + * PWMSAR can be read only if PWM is enabled. If the PWM is disabled, + * use the cached value. + */ + if (state->enabled) val = readl(imx->mmio_base + MX3_PWMSAR); - tmp = NSEC_PER_SEC * (u64)(val); - state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk); - } else { - state->duty_cycle = 0; - } + else + val = imx->duty_cycle; + + tmp = NSEC_PER_SEC * (u64)(val); + state->duty_cycle = DIV_ROUND_CLOSEST_ULL(tmp, pwm_clk); if (!state->enabled) pwm_imx27_clk_disable_unprepare(chip); @@ -220,63 +230,68 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm, pwm_get_state(pwm, &cstate); - if (state->enabled) { - c = clk_get_rate(imx->clk_per); - c *= state->period; - - do_div(c, 1000000000); - period_cycles = c; - - prescale = period_cycles / 0x10000 + 1; - - period_cycles /= prescale; - c = (unsigned long long)period_cycles * state->duty_cycle; - do_div(c, state->period); - duty_cycles = c; - - /* - * according to imx pwm RM, the real period value should be - * PERIOD value in PWMPR plus 2. - */ - if (period_cycles > 2) - period_cycles -= 2; - else - period_cycles = 0; - - /* - * Wait for a free FIFO slot if the PWM is already enabled, and - * flush the FIFO if the PWM was disabled and is about to be - * enabled. - */ - if (cstate.enabled) { - pwm_imx27_wait_fifo_slot(chip, pwm); - } else { - ret = pwm_imx27_clk_prepare_enable(chip); - if (ret) - return ret; - - pwm_imx27_sw_reset(chip); - } - - writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); - writel(period_cycles, imx->mmio_base + MX3_PWMPR); - - cr = MX3_PWMCR_PRESCALER_SET(prescale) | - MX3_PWMCR_STOPEN | MX3_PWMCR_DOZEN | MX3_PWMCR_WAITEN | - FIELD_PREP(MX3_PWMCR_CLKSRC, MX3_PWMCR_CLKSRC_IPG_HIGH) | - MX3_PWMCR_DBGEN | MX3_PWMCR_EN; - - if (state->polarity == PWM_POLARITY_INVERSED) - cr |= FIELD_PREP(MX3_PWMCR_POUTC, - MX3_PWMCR_POUTC_INVERTED); - - writel(cr, imx->mmio_base + MX3_PWMCR); - } else if (cstate.enabled) { - writel(0, imx->mmio_base + MX3_PWMCR); + c = clk_get_rate(imx->clk_per); + c *= state->period; - pwm_imx27_clk_disable_unprepare(chip); + do_div(c, 1000000000); + period_cycles = c; + + prescale = period_cycles / 0x10000 + 1; + + period_cycles /= prescale; + c = (unsigned long long)period_cycles * state->duty_cycle; + do_div(c, state->period); + duty_cycles = c; + + /* + * according to imx pwm RM, the real period value should be PERIOD + * value in PWMPR plus 2. + */ + if (period_cycles > 2) + period_cycles -= 2; + else + period_cycles = 0; + + /* + * Wait for a free FIFO slot if the PWM is already enabled, and flush + * the FIFO if the PWM was disabled and is about to be enabled. + */ + if (cstate.enabled) { + pwm_imx27_wait_fifo_slot(chip, pwm); + } else { + ret = pwm_imx27_clk_prepare_enable(chip); + if (ret) + return ret; + + pwm_imx27_sw_reset(chip); } + writel(duty_cycles, imx->mmio_base + MX3_PWMSAR); + writel(period_cycles, imx->mmio_base + MX3_PWMPR); + + /* + * Store the duty cycle for future reference in cases where the + * MX3_PWMSAR register can't be read (i.e. when the PWM is disabled). + */ + imx->duty_cycle = duty_cycles; + + cr = MX3_PWMCR_PRESCALER_SET(prescale) | + MX3_PWMCR_STOPEN | MX3_PWMCR_DOZEN | MX3_PWMCR_WAITEN | + FIELD_PREP(MX3_PWMCR_CLKSRC, MX3_PWMCR_CLKSRC_IPG_HIGH) | + MX3_PWMCR_DBGEN; + + if (state->polarity == PWM_POLARITY_INVERSED) + cr |= FIELD_PREP(MX3_PWMCR_POUTC, + MX3_PWMCR_POUTC_INVERTED); + + if (state->enabled) + cr |= MX3_PWMCR_EN; + + writel(cr, imx->mmio_base + MX3_PWMCR); + + if (!state->enabled && cstate.enabled) + pwm_imx27_clk_disable_unprepare(chip); + return 0; } @@ -304,9 +319,13 @@ static int pwm_imx27_probe(struct platform_device *pdev) imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(imx->clk_ipg)) { - dev_err(&pdev->dev, "getting ipg clock failed with %ld\n", - PTR_ERR(imx->clk_ipg)); - return PTR_ERR(imx->clk_ipg); + int ret = PTR_ERR(imx->clk_ipg); + + if (ret != -EPROBE_DEFER) + dev_err(&pdev->dev, + "getting ipg clock failed with %d\n", + ret); + return ret; } imx->clk_per = devm_clk_get(&pdev->dev, "per"); diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c index b14376b47ac8..f2e57fcf8f8b 100644 --- a/drivers/pwm/pwm-mxs.c +++ b/drivers/pwm/pwm-mxs.c @@ -25,12 +25,16 @@ #define PERIOD_PERIOD(p) ((p) & 0xffff) #define PERIOD_PERIOD_MAX 0x10000 #define PERIOD_ACTIVE_HIGH (3 << 16) +#define PERIOD_ACTIVE_LOW (2 << 16) +#define PERIOD_INACTIVE_HIGH (3 << 18) #define PERIOD_INACTIVE_LOW (2 << 18) +#define PERIOD_POLARITY_NORMAL (PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LOW) +#define PERIOD_POLARITY_INVERSE (PERIOD_ACTIVE_LOW | PERIOD_INACTIVE_HIGH) #define PERIOD_CDIV(div) (((div) & 0x7) << 20) #define PERIOD_CDIV_MAX 8 -static const unsigned int cdiv[PERIOD_CDIV_MAX] = { - 1, 2, 4, 8, 16, 64, 256, 1024 +static const u8 cdiv_shift[PERIOD_CDIV_MAX] = { + 0, 1, 2, 3, 4, 6, 8, 10 }; struct mxs_pwm_chip { @@ -41,19 +45,34 @@ struct mxs_pwm_chip { #define to_mxs_pwm_chip(_chip) container_of(_chip, struct mxs_pwm_chip, chip) -static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) +static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) { struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); int ret, div = 0; unsigned int period_cycles, duty_cycles; unsigned long rate; unsigned long long c; + unsigned int pol_bits; + + /* + * If the PWM channel is disabled, make sure to turn on the + * clock before calling clk_get_rate() and writing to the + * registers. Otherwise, just keep it enabled. + */ + if (!pwm_is_enabled(pwm)) { + ret = clk_prepare_enable(mxs->clk); + if (ret) + return ret; + } + + if (!state->enabled && pwm_is_enabled(pwm)) + writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR); rate = clk_get_rate(mxs->clk); while (1) { - c = rate / cdiv[div]; - c = c * period_ns; + c = rate >> cdiv_shift[div]; + c = c * state->period; do_div(c, 1000000000); if (c < PERIOD_PERIOD_MAX) break; @@ -63,62 +82,40 @@ static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, } period_cycles = c; - c *= duty_ns; - do_div(c, period_ns); + c *= state->duty_cycle; + do_div(c, state->period); duty_cycles = c; /* - * If the PWM channel is disabled, make sure to turn on the clock - * before writing the register. Otherwise, keep it enabled. + * The data sheet the says registers must be written to in + * this order (ACTIVEn, then PERIODn). Also, the new settings + * only take effect at the beginning of a new period, avoiding + * glitches. */ - if (!pwm_is_enabled(pwm)) { - ret = clk_prepare_enable(mxs->clk); - if (ret) - return ret; - } + pol_bits = state->polarity == PWM_POLARITY_NORMAL ? + PERIOD_POLARITY_NORMAL : PERIOD_POLARITY_INVERSE; writel(duty_cycles << 16, - mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20); - writel(PERIOD_PERIOD(period_cycles) | PERIOD_ACTIVE_HIGH | - PERIOD_INACTIVE_LOW | PERIOD_CDIV(div), - mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20); - - /* - * If the PWM is not enabled, turn the clock off again to save power. - */ - if (!pwm_is_enabled(pwm)) + mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20); + writel(PERIOD_PERIOD(period_cycles) | pol_bits | PERIOD_CDIV(div), + mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20); + + if (state->enabled) { + if (!pwm_is_enabled(pwm)) { + /* + * The clock was enabled above. Just enable + * the channel in the control register. + */ + writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET); + } + } else { clk_disable_unprepare(mxs->clk); - - return 0; -} - -static int mxs_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); - int ret; - - ret = clk_prepare_enable(mxs->clk); - if (ret) - return ret; - - writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + SET); - + } return 0; } -static void mxs_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct mxs_pwm_chip *mxs = to_mxs_pwm_chip(chip); - - writel(1 << pwm->hwpwm, mxs->base + PWM_CTRL + CLR); - - clk_disable_unprepare(mxs->clk); -} - static const struct pwm_ops mxs_pwm_ops = { - .config = mxs_pwm_config, - .enable = mxs_pwm_enable, - .disable = mxs_pwm_disable, + .apply = mxs_pwm_apply, .owner = THIS_MODULE, }; @@ -142,6 +139,8 @@ static int mxs_pwm_probe(struct platform_device *pdev) mxs->chip.dev = &pdev->dev; mxs->chip.ops = &mxs_pwm_ops; + mxs->chip.of_xlate = of_pwm_xlate_with_flags; + mxs->chip.of_pwm_n_cells = 3; mxs->chip.base = -1; ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm); diff --git a/drivers/pwm/pwm-omap-dmtimer.c b/drivers/pwm/pwm-omap-dmtimer.c index 00772fc53490..88a3c5690fea 100644 --- a/drivers/pwm/pwm-omap-dmtimer.c +++ b/drivers/pwm/pwm-omap-dmtimer.c @@ -256,7 +256,7 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev) if (!timer_pdev) { dev_err(&pdev->dev, "Unable to find Timer pdev\n"); ret = -ENODEV; - goto put; + goto err_find_timer_pdev; } timer_pdata = dev_get_platdata(&timer_pdev->dev); @@ -264,7 +264,7 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev) dev_dbg(&pdev->dev, "dmtimer pdata structure NULL, deferring probe\n"); ret = -EPROBE_DEFER; - goto put; + goto err_platdata; } pdata = timer_pdata->timer_ops; @@ -283,30 +283,25 @@ static int pwm_omap_dmtimer_probe(struct platform_device *pdev) !pdata->write_counter) { dev_err(&pdev->dev, "Incomplete dmtimer pdata structure\n"); ret = -EINVAL; - goto put; + goto err_platdata; } if (!of_get_property(timer, "ti,timer-pwm", NULL)) { dev_err(&pdev->dev, "Missing ti,timer-pwm capability\n"); ret = -ENODEV; - goto put; + goto err_timer_property; } dm_timer = pdata->request_by_node(timer); if (!dm_timer) { ret = -EPROBE_DEFER; - goto put; + goto err_request_timer; } -put: - of_node_put(timer); - if (ret < 0) - return ret; - omap = devm_kzalloc(&pdev->dev, sizeof(*omap), GFP_KERNEL); if (!omap) { - pdata->free(dm_timer); - return -ENOMEM; + ret = -ENOMEM; + goto err_alloc_omap; } omap->pdata = pdata; @@ -339,27 +334,56 @@ put: ret = pwmchip_add(&omap->chip); if (ret < 0) { dev_err(&pdev->dev, "failed to register PWM\n"); - omap->pdata->free(omap->dm_timer); - return ret; + goto err_pwmchip_add; } + of_node_put(timer); + platform_set_drvdata(pdev, omap); return 0; + +err_pwmchip_add: + + /* + * *omap is allocated using devm_kzalloc, + * so no free necessary here + */ +err_alloc_omap: + + pdata->free(dm_timer); +err_request_timer: + +err_timer_property: +err_platdata: + + put_device(&timer_pdev->dev); +err_find_timer_pdev: + + of_node_put(timer); + + return ret; } static int pwm_omap_dmtimer_remove(struct platform_device *pdev) { struct pwm_omap_dmtimer_chip *omap = platform_get_drvdata(pdev); + int ret; + + ret = pwmchip_remove(&omap->chip); + if (ret) + return ret; if (pm_runtime_active(&omap->dm_timer_pdev->dev)) omap->pdata->stop(omap->dm_timer); omap->pdata->free(omap->dm_timer); + put_device(&omap->dm_timer_pdev->dev); + mutex_destroy(&omap->mutex); - return pwmchip_remove(&omap->chip); + return 0; } static const struct of_device_id pwm_omap_dmtimer_of_match[] = { diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 168684b02ebc..b07bdca3d510 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -159,13 +159,9 @@ static void pca9685_pwm_gpio_set(struct gpio_chip *gpio, unsigned int offset, static void pca9685_pwm_gpio_free(struct gpio_chip *gpio, unsigned int offset) { struct pca9685 *pca = gpiochip_get_data(gpio); - struct pwm_device *pwm; pca9685_pwm_gpio_set(gpio, offset, 0); pm_runtime_put(pca->chip.dev); - mutex_lock(&pca->lock); - pwm = &pca->chip.pwms[offset]; - mutex_unlock(&pca->lock); } static int pca9685_pwm_gpio_get_direction(struct gpio_chip *chip, diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c index 852eb2347954..2685577b6dd4 100644 --- a/drivers/pwm/pwm-rcar.c +++ b/drivers/pwm/pwm-rcar.c @@ -3,6 +3,9 @@ * R-Car PWM Timer driver * * Copyright (C) 2015 Renesas Electronics Corporation + * + * Limitations: + * - The hardware cannot generate a 0% duty cycle. */ #include <linux/clk.h> @@ -161,11 +164,9 @@ static int rcar_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); - struct pwm_state cur_state; int div, ret; /* This HW/driver only supports normal polarity */ - pwm_get_state(pwm, &cur_state); if (state->polarity != PWM_POLARITY_NORMAL) return -ENOTSUPP; diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index 7ff48c14fae8..d3be944f2ae9 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -377,9 +377,7 @@ static int stm32_pwm_config(struct stm32_pwm *priv, int ch, else regmap_update_bits(priv->regmap, TIM_CCMR2, mask, ccmr); - regmap_update_bits(priv->regmap, TIM_BDTR, - TIM_BDTR_MOE | TIM_BDTR_AOE, - TIM_BDTR_MOE | TIM_BDTR_AOE); + regmap_update_bits(priv->regmap, TIM_BDTR, TIM_BDTR_MOE, TIM_BDTR_MOE); return 0; } diff --git a/drivers/pwm/pwm-sun4i.c b/drivers/pwm/pwm-sun4i.c index 581d23287333..3e3efa6c768f 100644 --- a/drivers/pwm/pwm-sun4i.c +++ b/drivers/pwm/pwm-sun4i.c @@ -3,6 +3,10 @@ * Driver for Allwinner sun4i Pulse Width Modulation Controller * * Copyright (C) 2014 Alexandre Belloni <alexandre.belloni@free-electrons.com> + * + * Limitations: + * - When outputing the source clock directly, the PWM logic will be bypassed + * and the currently running period is not guaranteed to be completed */ #include <linux/bitops.h> @@ -16,6 +20,7 @@ #include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pwm.h> +#include <linux/reset.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/time.h> @@ -72,12 +77,15 @@ static const u32 prescaler_table[] = { struct sun4i_pwm_data { bool has_prescaler_bypass; + bool has_direct_mod_clk_output; unsigned int npwm; }; struct sun4i_pwm_chip { struct pwm_chip chip; + struct clk *bus_clk; struct clk *clk; + struct reset_control *rst; void __iomem *base; spinlock_t ctrl_lock; const struct sun4i_pwm_data *data; @@ -115,6 +123,20 @@ static void sun4i_pwm_get_state(struct pwm_chip *chip, val = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG); + /* + * PWM chapter in H6 manual has a diagram which explains that if bypass + * bit is set, no other setting has any meaning. Even more, experiment + * proved that also enable bit is ignored in this case. + */ + if ((val & BIT_CH(PWM_BYPASS, pwm->hwpwm)) && + sun4i_pwm->data->has_direct_mod_clk_output) { + state->period = DIV_ROUND_UP_ULL(NSEC_PER_SEC, clk_rate); + state->duty_cycle = DIV_ROUND_UP_ULL(state->period, 2); + state->polarity = PWM_POLARITY_NORMAL; + state->enabled = true; + return; + } + if ((PWM_REG_PRESCAL(val, pwm->hwpwm) == PWM_PRESCAL_MASK) && sun4i_pwm->data->has_prescaler_bypass) prescaler = 1; @@ -146,13 +168,24 @@ static void sun4i_pwm_get_state(struct pwm_chip *chip, static int sun4i_pwm_calculate(struct sun4i_pwm_chip *sun4i_pwm, const struct pwm_state *state, - u32 *dty, u32 *prd, unsigned int *prsclr) + u32 *dty, u32 *prd, unsigned int *prsclr, + bool *bypass) { u64 clk_rate, div = 0; - unsigned int pval, prescaler = 0; + unsigned int prescaler = 0; clk_rate = clk_get_rate(sun4i_pwm->clk); + *bypass = sun4i_pwm->data->has_direct_mod_clk_output && + state->enabled && + (state->period * clk_rate >= NSEC_PER_SEC) && + (state->period * clk_rate < 2 * NSEC_PER_SEC) && + (state->duty_cycle * clk_rate * 2 >= NSEC_PER_SEC); + + /* Skip calculation of other parameters if we bypass them */ + if (*bypass) + return 0; + if (sun4i_pwm->data->has_prescaler_bypass) { /* First, test without any prescaler when available */ prescaler = PWM_PRESCAL_MASK; @@ -170,9 +203,11 @@ static int sun4i_pwm_calculate(struct sun4i_pwm_chip *sun4i_pwm, if (prescaler == 0) { /* Go up from the first divider */ for (prescaler = 0; prescaler < PWM_PRESCAL_MASK; prescaler++) { - if (!prescaler_table[prescaler]) + unsigned int pval = prescaler_table[prescaler]; + + if (!pval) continue; - pval = prescaler_table[prescaler]; + div = clk_rate; do_div(div, pval); div = div * state->period; @@ -199,10 +234,11 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, { struct sun4i_pwm_chip *sun4i_pwm = to_sun4i_pwm_chip(chip); struct pwm_state cstate; - u32 ctrl; + u32 ctrl, duty = 0, period = 0, val; int ret; - unsigned int delay_us; + unsigned int delay_us, prescaler = 0; unsigned long now; + bool bypass; pwm_get_state(pwm, &cstate); @@ -214,46 +250,52 @@ static int sun4i_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, } } + ret = sun4i_pwm_calculate(sun4i_pwm, state, &duty, &period, &prescaler, + &bypass); + if (ret) { + dev_err(chip->dev, "period exceeds the maximum value\n"); + if (!cstate.enabled) + clk_disable_unprepare(sun4i_pwm->clk); + return ret; + } + spin_lock(&sun4i_pwm->ctrl_lock); ctrl = sun4i_pwm_readl(sun4i_pwm, PWM_CTRL_REG); - if ((cstate.period != state->period) || - (cstate.duty_cycle != state->duty_cycle)) { - u32 period, duty, val; - unsigned int prescaler; - - ret = sun4i_pwm_calculate(sun4i_pwm, state, - &duty, &period, &prescaler); - if (ret) { - dev_err(chip->dev, "period exceeds the maximum value\n"); + if (sun4i_pwm->data->has_direct_mod_clk_output) { + if (bypass) { + ctrl |= BIT_CH(PWM_BYPASS, pwm->hwpwm); + /* We can skip other parameter */ + sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG); spin_unlock(&sun4i_pwm->ctrl_lock); - if (!cstate.enabled) - clk_disable_unprepare(sun4i_pwm->clk); - return ret; + return 0; } - if (PWM_REG_PRESCAL(ctrl, pwm->hwpwm) != prescaler) { - /* Prescaler changed, the clock has to be gated */ - ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm); - sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG); + ctrl &= ~BIT_CH(PWM_BYPASS, pwm->hwpwm); + } - ctrl &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm); - ctrl |= BIT_CH(prescaler, pwm->hwpwm); - } + if (PWM_REG_PRESCAL(ctrl, pwm->hwpwm) != prescaler) { + /* Prescaler changed, the clock has to be gated */ + ctrl &= ~BIT_CH(PWM_CLK_GATING, pwm->hwpwm); + sun4i_pwm_writel(sun4i_pwm, ctrl, PWM_CTRL_REG); - val = (duty & PWM_DTY_MASK) | PWM_PRD(period); - sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm)); - sun4i_pwm->next_period[pwm->hwpwm] = jiffies + - usecs_to_jiffies(cstate.period / 1000 + 1); - sun4i_pwm->needs_delay[pwm->hwpwm] = true; + ctrl &= ~BIT_CH(PWM_PRESCAL_MASK, pwm->hwpwm); + ctrl |= BIT_CH(prescaler, pwm->hwpwm); } + val = (duty & PWM_DTY_MASK) | PWM_PRD(period); + sun4i_pwm_writel(sun4i_pwm, val, PWM_CH_PRD(pwm->hwpwm)); + sun4i_pwm->next_period[pwm->hwpwm] = jiffies + + usecs_to_jiffies(cstate.period / 1000 + 1); + sun4i_pwm->needs_delay[pwm->hwpwm] = true; + if (state->polarity != PWM_POLARITY_NORMAL) ctrl &= ~BIT_CH(PWM_ACT_STATE, pwm->hwpwm); else ctrl |= BIT_CH(PWM_ACT_STATE, pwm->hwpwm); ctrl |= BIT_CH(PWM_CLK_GATING, pwm->hwpwm); + if (state->enabled) { ctrl |= BIT_CH(PWM_EN, pwm->hwpwm); } else if (!sun4i_pwm->needs_delay[pwm->hwpwm]) { @@ -319,6 +361,12 @@ static const struct sun4i_pwm_data sun4i_pwm_single_bypass = { .npwm = 1, }; +static const struct sun4i_pwm_data sun50i_h6_pwm_data = { + .has_prescaler_bypass = true, + .has_direct_mod_clk_output = true, + .npwm = 2, +}; + static const struct of_device_id sun4i_pwm_dt_ids[] = { { .compatible = "allwinner,sun4i-a10-pwm", @@ -336,6 +384,9 @@ static const struct of_device_id sun4i_pwm_dt_ids[] = { .compatible = "allwinner,sun8i-h3-pwm", .data = &sun4i_pwm_single_bypass, }, { + .compatible = "allwinner,sun50i-h6-pwm", + .data = &sun50i_h6_pwm_data, + }, { /* sentinel */ }, }; @@ -360,9 +411,69 @@ static int sun4i_pwm_probe(struct platform_device *pdev) if (IS_ERR(pwm->base)) return PTR_ERR(pwm->base); - pwm->clk = devm_clk_get(&pdev->dev, NULL); - if (IS_ERR(pwm->clk)) + /* + * All hardware variants need a source clock that is divided and + * then feeds the counter that defines the output wave form. In the + * device tree this clock is either unnamed or called "mod". + * Some variants (e.g. H6) need another clock to access the + * hardware registers; this is called "bus". + * So we request "mod" first (and ignore the corner case that a + * parent provides a "mod" clock while the right one would be the + * unnamed one of the PWM device) and if this is not found we fall + * back to the first clock of the PWM. + */ + pwm->clk = devm_clk_get_optional(&pdev->dev, "mod"); + if (IS_ERR(pwm->clk)) { + if (PTR_ERR(pwm->clk) != -EPROBE_DEFER) + dev_err(&pdev->dev, "get mod clock failed %pe\n", + pwm->clk); return PTR_ERR(pwm->clk); + } + + if (!pwm->clk) { + pwm->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(pwm->clk)) { + if (PTR_ERR(pwm->clk) != -EPROBE_DEFER) + dev_err(&pdev->dev, "get unnamed clock failed %pe\n", + pwm->clk); + return PTR_ERR(pwm->clk); + } + } + + pwm->bus_clk = devm_clk_get_optional(&pdev->dev, "bus"); + if (IS_ERR(pwm->bus_clk)) { + if (PTR_ERR(pwm->bus_clk) != -EPROBE_DEFER) + dev_err(&pdev->dev, "get bus clock failed %pe\n", + pwm->bus_clk); + return PTR_ERR(pwm->bus_clk); + } + + pwm->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); + if (IS_ERR(pwm->rst)) { + if (PTR_ERR(pwm->rst) != -EPROBE_DEFER) + dev_err(&pdev->dev, "get reset failed %pe\n", + pwm->rst); + return PTR_ERR(pwm->rst); + } + + /* Deassert reset */ + ret = reset_control_deassert(pwm->rst); + if (ret) { + dev_err(&pdev->dev, "cannot deassert reset control: %pe\n", + ERR_PTR(ret)); + return ret; + } + + /* + * We're keeping the bus clock on for the sake of simplicity. + * Actually it only needs to be on for hardware register accesses. + */ + ret = clk_prepare_enable(pwm->bus_clk); + if (ret) { + dev_err(&pdev->dev, "cannot prepare and enable bus_clk %pe\n", + ERR_PTR(ret)); + goto err_bus; + } pwm->chip.dev = &pdev->dev; pwm->chip.ops = &sun4i_pwm_ops; @@ -376,19 +487,34 @@ static int sun4i_pwm_probe(struct platform_device *pdev) ret = pwmchip_add(&pwm->chip); if (ret < 0) { dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret); - return ret; + goto err_pwm_add; } platform_set_drvdata(pdev, pwm); return 0; + +err_pwm_add: + clk_disable_unprepare(pwm->bus_clk); +err_bus: + reset_control_assert(pwm->rst); + + return ret; } static int sun4i_pwm_remove(struct platform_device *pdev) { struct sun4i_pwm_chip *pwm = platform_get_drvdata(pdev); + int ret; + + ret = pwmchip_remove(&pwm->chip); + if (ret) + return ret; + + clk_disable_unprepare(pwm->bus_clk); + reset_control_assert(pwm->rst); - return pwmchip_remove(&pwm->chip); + return 0; } static struct platform_driver sun4i_pwm_driver = { |