diff options
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/pwm-atmel.c | 273 |
1 files changed, 129 insertions, 144 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index 67a7023be5c2..f147154d9cb2 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -58,17 +58,22 @@ #define PWM_MAX_PRD 0xFFFF #define PRD_MAX_PRES 10 +struct atmel_pwm_registers { + u8 period; + u8 period_upd; + u8 duty; + u8 duty_upd; +}; + struct atmel_pwm_chip { struct pwm_chip chip; struct clk *clk; void __iomem *base; + const struct atmel_pwm_registers *regs; unsigned int updated_pwms; /* ISR is cleared when read, ensure only one thread does that */ struct mutex isr_lock; - - void (*config)(struct pwm_chip *chip, struct pwm_device *pwm, - unsigned long dty, unsigned long prd); }; static inline struct atmel_pwm_chip *to_atmel_pwm_chip(struct pwm_chip *chip) @@ -105,153 +110,71 @@ static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip, writel_relaxed(val, chip->base + base + offset); } -static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) +static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip, + const struct pwm_state *state, + unsigned long *cprd, u32 *pres) { struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); - unsigned long prd, dty; - unsigned long long div; - unsigned int pres = 0; - u32 val; - int ret; - - if (pwm_is_enabled(pwm) && (period_ns != pwm_get_period(pwm))) { - dev_err(chip->dev, "cannot change PWM period while enabled\n"); - return -EBUSY; - } + unsigned long long cycles = state->period; /* Calculate the period cycles and prescale value */ - div = (unsigned long long)clk_get_rate(atmel_pwm->clk) * period_ns; - do_div(div, NSEC_PER_SEC); + cycles *= clk_get_rate(atmel_pwm->clk); + do_div(cycles, NSEC_PER_SEC); - while (div > PWM_MAX_PRD) { - div >>= 1; - pres++; - } + for (*pres = 0; cycles > PWM_MAX_PRD; cycles >>= 1) + (*pres)++; - if (pres > PRD_MAX_PRES) { + if (*pres > PRD_MAX_PRES) { dev_err(chip->dev, "pres exceeds the maximum value\n"); return -EINVAL; } - /* Calculate the duty cycles */ - prd = div; - div *= duty_ns; - do_div(div, period_ns); - dty = prd - div; - - ret = clk_enable(atmel_pwm->clk); - if (ret) { - dev_err(chip->dev, "failed to enable PWM clock\n"); - return ret; - } - - /* It is necessary to preserve CPOL, inside CMR */ - val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); - val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK); - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); - atmel_pwm->config(chip, pwm, dty, prd); - mutex_lock(&atmel_pwm->isr_lock); - atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR); - atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm); - mutex_unlock(&atmel_pwm->isr_lock); + *cprd = cycles; - clk_disable(atmel_pwm->clk); - return ret; + return 0; } -static void atmel_pwm_config_v1(struct pwm_chip *chip, struct pwm_device *pwm, - unsigned long dty, unsigned long prd) +static void atmel_pwm_calculate_cdty(const struct pwm_state *state, + unsigned long cprd, unsigned long *cdty) { - struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); - unsigned int val; + unsigned long long cycles = state->duty_cycle; - - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CUPD, dty); - - val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); - val &= ~PWM_CMR_UPD_CDTY; - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); - - /* - * 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 (pwm_is_enabled(pwm)) - return; - /* - * If the PWM channel is disabled, write value to duty and period - * registers directly. - */ - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CDTY, dty); - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CPRD, prd); + cycles *= cprd; + do_div(cycles, state->period); + *cdty = cprd - cycles; } -static void atmel_pwm_config_v2(struct pwm_chip *chip, struct pwm_device *pwm, - unsigned long dty, unsigned long prd) -{ - struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); - - if (pwm_is_enabled(pwm)) { - /* - * If the PWM channel is enabled, using the duty update register - * to update the value. - */ - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV2_CDTYUPD, dty); - } else { - /* - * If the PWM channel is disabled, write value to duty and - * period registers directly. - */ - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV2_CDTY, dty); - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV2_CPRD, prd); - } -} - -static int atmel_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm, - enum pwm_polarity polarity) +static void atmel_pwm_update_cdty(struct pwm_chip *chip, struct pwm_device *pwm, + unsigned long cdty) { struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); u32 val; - int ret; - - val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); - if (polarity == PWM_POLARITY_NORMAL) - val &= ~PWM_CMR_CPOL; - else - val |= PWM_CMR_CPOL; - - ret = clk_enable(atmel_pwm->clk); - if (ret) { - dev_err(chip->dev, "failed to enable PWM clock\n"); - return ret; + if (atmel_pwm->regs->duty_upd == + atmel_pwm->regs->period_upd) { + val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); + val &= ~PWM_CMR_UPD_CDTY; + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); } - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); - - clk_disable(atmel_pwm->clk); - - return 0; + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, + atmel_pwm->regs->duty_upd, cdty); } -static int atmel_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +static void atmel_pwm_set_cprd_cdty(struct pwm_chip *chip, + struct pwm_device *pwm, + unsigned long cprd, unsigned long cdty) { struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); - int ret; - - ret = clk_enable(atmel_pwm->clk); - if (ret) { - dev_err(chip->dev, "failed to enable PWM clock\n"); - return ret; - } - atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm); - - return 0; + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, + atmel_pwm->regs->duty, cdty); + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, + atmel_pwm->regs->period, cprd); } -static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm, + bool disable_clk) { struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); unsigned long timeout = jiffies + 2 * HZ; @@ -282,37 +205,99 @@ static void atmel_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) time_before(jiffies, timeout)) usleep_range(10, 100); - clk_disable(atmel_pwm->clk); + if (disable_clk) + clk_disable(atmel_pwm->clk); +} + +static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); + struct pwm_state cstate; + unsigned long cprd, cdty; + u32 pres, val; + int ret; + + pwm_get_state(pwm, &cstate); + + if (state->enabled) { + if (cstate.enabled && + cstate.polarity == state->polarity && + cstate.period == state->period) { + cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, + atmel_pwm->regs->period); + atmel_pwm_calculate_cdty(state, cprd, &cdty); + atmel_pwm_update_cdty(chip, pwm, cdty); + return 0; + } + + ret = atmel_pwm_calculate_cprd_and_pres(chip, state, &cprd, + &pres); + if (ret) { + dev_err(chip->dev, + "failed to calculate cprd and prescaler\n"); + return ret; + } + + atmel_pwm_calculate_cdty(state, cprd, &cdty); + + if (cstate.enabled) { + atmel_pwm_disable(chip, pwm, false); + } else { + ret = clk_enable(atmel_pwm->clk); + if (ret) { + dev_err(chip->dev, "failed to enable clock\n"); + return ret; + } + } + + /* It is necessary to preserve CPOL, inside CMR */ + val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); + val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK); + if (state->polarity == PWM_POLARITY_NORMAL) + val &= ~PWM_CMR_CPOL; + else + val |= PWM_CMR_CPOL; + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); + atmel_pwm_set_cprd_cdty(chip, pwm, cprd, cdty); + mutex_lock(&atmel_pwm->isr_lock); + atmel_pwm->updated_pwms |= atmel_pwm_readl(atmel_pwm, PWM_ISR); + atmel_pwm->updated_pwms &= ~(1 << pwm->hwpwm); + mutex_unlock(&atmel_pwm->isr_lock); + atmel_pwm_writel(atmel_pwm, PWM_ENA, 1 << pwm->hwpwm); + } else if (cstate.enabled) { + atmel_pwm_disable(chip, pwm, true); + } + + return 0; } static const struct pwm_ops atmel_pwm_ops = { - .config = atmel_pwm_config, - .set_polarity = atmel_pwm_set_polarity, - .enable = atmel_pwm_enable, - .disable = atmel_pwm_disable, + .apply = atmel_pwm_apply, .owner = THIS_MODULE, }; -struct atmel_pwm_data { - void (*config)(struct pwm_chip *chip, struct pwm_device *pwm, - unsigned long dty, unsigned long prd); -}; - -static const struct atmel_pwm_data atmel_pwm_data_v1 = { - .config = atmel_pwm_config_v1, +static const struct atmel_pwm_registers atmel_pwm_regs_v1 = { + .period = PWMV1_CPRD, + .period_upd = PWMV1_CUPD, + .duty = PWMV1_CDTY, + .duty_upd = PWMV1_CUPD, }; -static const struct atmel_pwm_data atmel_pwm_data_v2 = { - .config = atmel_pwm_config_v2, +static const struct atmel_pwm_registers atmel_pwm_regs_v2 = { + .period = PWMV2_CPRD, + .period_upd = PWMV2_CPRDUPD, + .duty = PWMV2_CDTY, + .duty_upd = PWMV2_CDTYUPD, }; static const struct platform_device_id atmel_pwm_devtypes[] = { { .name = "at91sam9rl-pwm", - .driver_data = (kernel_ulong_t)&atmel_pwm_data_v1, + .driver_data = (kernel_ulong_t)&atmel_pwm_regs_v1, }, { .name = "sama5d3-pwm", - .driver_data = (kernel_ulong_t)&atmel_pwm_data_v2, + .driver_data = (kernel_ulong_t)&atmel_pwm_regs_v2, }, { /* sentinel */ }, @@ -322,17 +307,17 @@ MODULE_DEVICE_TABLE(platform, atmel_pwm_devtypes); static const struct of_device_id atmel_pwm_dt_ids[] = { { .compatible = "atmel,at91sam9rl-pwm", - .data = &atmel_pwm_data_v1, + .data = &atmel_pwm_regs_v1, }, { .compatible = "atmel,sama5d3-pwm", - .data = &atmel_pwm_data_v2, + .data = &atmel_pwm_regs_v2, }, { /* sentinel */ }, }; MODULE_DEVICE_TABLE(of, atmel_pwm_dt_ids); -static inline const struct atmel_pwm_data * +static inline const struct atmel_pwm_registers * atmel_pwm_get_driver_data(struct platform_device *pdev) { const struct platform_device_id *id; @@ -342,18 +327,18 @@ atmel_pwm_get_driver_data(struct platform_device *pdev) id = platform_get_device_id(pdev); - return (struct atmel_pwm_data *)id->driver_data; + return (struct atmel_pwm_registers *)id->driver_data; } static int atmel_pwm_probe(struct platform_device *pdev) { - const struct atmel_pwm_data *data; + const struct atmel_pwm_registers *regs; struct atmel_pwm_chip *atmel_pwm; struct resource *res; int ret; - data = atmel_pwm_get_driver_data(pdev); - if (!data) + regs = atmel_pwm_get_driver_data(pdev); + if (!regs) return -ENODEV; atmel_pwm = devm_kzalloc(&pdev->dev, sizeof(*atmel_pwm), GFP_KERNEL); @@ -385,7 +370,7 @@ static int atmel_pwm_probe(struct platform_device *pdev) atmel_pwm->chip.base = -1; atmel_pwm->chip.npwm = 4; - atmel_pwm->config = data->config; + atmel_pwm->regs = regs; atmel_pwm->updated_pwms = 0; mutex_init(&atmel_pwm->isr_lock); |