diff options
Diffstat (limited to 'drivers/pwm/pwm-rcar.c')
| -rw-r--r-- | drivers/pwm/pwm-rcar.c | 201 |
1 files changed, 79 insertions, 122 deletions
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c index a41812fc6f95..578dbdd2d5a7 100644 --- a/drivers/pwm/pwm-rcar.c +++ b/drivers/pwm/pwm-rcar.c @@ -3,11 +3,17 @@ * R-Car PWM Timer driver * * Copyright (C) 2015 Renesas Electronics Corporation + * + * Limitations: + * - The hardware cannot generate a 0% duty cycle. */ +#include <linux/bitfield.h> #include <linux/clk.h> #include <linux/err.h> #include <linux/io.h> +#include <linux/log2.h> +#include <linux/math64.h> #include <linux/module.h> #include <linux/of.h> #include <linux/platform_device.h> @@ -33,14 +39,13 @@ #define RCAR_PWMCNT_PH0_SHIFT 0 struct rcar_pwm_chip { - struct pwm_chip chip; void __iomem *base; struct clk *clk; }; static inline struct rcar_pwm_chip *to_rcar_pwm_chip(struct pwm_chip *chip) { - return container_of(chip, struct rcar_pwm_chip, chip); + return pwmchip_get_drvdata(chip); } static void rcar_pwm_write(struct rcar_pwm_chip *rp, u32 data, @@ -68,19 +73,15 @@ static void rcar_pwm_update(struct rcar_pwm_chip *rp, u32 mask, u32 data, static int rcar_pwm_get_clock_division(struct rcar_pwm_chip *rp, int period_ns) { unsigned long clk_rate = clk_get_rate(rp->clk); - unsigned long long max; /* max cycle / nanoseconds */ - unsigned int div; + u64 div, tmp; if (clk_rate == 0) return -EINVAL; - for (div = 0; div <= RCAR_PWM_MAX_DIVISION; div++) { - max = (unsigned long long)NSEC_PER_SEC * RCAR_PWM_MAX_CYCLE * - (1 << div); - do_div(max, clk_rate); - if (period_ns <= max) - break; - } + div = (u64)NSEC_PER_SEC * RCAR_PWM_MAX_CYCLE; + tmp = (u64)period_ns * clk_rate + div - 1; + tmp = div64_u64(tmp, div); + div = ilog2(tmp - 1) + 1; return (div <= RCAR_PWM_MAX_DIVISION) ? div : -ERANGE; } @@ -102,23 +103,24 @@ static void rcar_pwm_set_clock_control(struct rcar_pwm_chip *rp, rcar_pwm_write(rp, value, RCAR_PWMCR); } -static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, int duty_ns, - int period_ns) +static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, u64 duty_ns, + u64 period_ns) { - unsigned long long one_cycle, tmp; /* 0.01 nanoseconds */ + unsigned long long tmp; unsigned long clk_rate = clk_get_rate(rp->clk); u32 cyc, ph; - one_cycle = (unsigned long long)NSEC_PER_SEC * 100ULL * (1 << div); - do_div(one_cycle, clk_rate); + /* div <= 24 == RCAR_PWM_MAX_DIVISION, so the shift doesn't overflow. */ + tmp = mul_u64_u64_div_u64(period_ns, clk_rate, (u64)NSEC_PER_SEC << div); + if (tmp > FIELD_MAX(RCAR_PWMCNT_CYC0_MASK)) + tmp = FIELD_MAX(RCAR_PWMCNT_CYC0_MASK); - tmp = period_ns * 100ULL; - do_div(tmp, one_cycle); - cyc = (tmp << RCAR_PWMCNT_CYC0_SHIFT) & RCAR_PWMCNT_CYC0_MASK; + cyc = FIELD_PREP(RCAR_PWMCNT_CYC0_MASK, tmp); - tmp = duty_ns * 100ULL; - do_div(tmp, one_cycle); - ph = tmp & RCAR_PWMCNT_PH0_MASK; + tmp = mul_u64_u64_div_u64(duty_ns, clk_rate, (u64)NSEC_PER_SEC << div); + if (tmp > FIELD_MAX(RCAR_PWMCNT_PH0_MASK)) + tmp = FIELD_MAX(RCAR_PWMCNT_PH0_MASK); + ph = FIELD_PREP(RCAR_PWMCNT_PH0_MASK, tmp); /* Avoid prohibited setting */ if (cyc == 0 || ph == 0) @@ -131,47 +133,16 @@ static int rcar_pwm_set_counter(struct rcar_pwm_chip *rp, int div, int duty_ns, static int rcar_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) { - return pm_runtime_get_sync(chip->dev); + return pm_runtime_get_sync(pwmchip_parent(chip)); } static void rcar_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) { - pm_runtime_put(chip->dev); -} - -static int rcar_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, - int duty_ns, int period_ns) -{ - struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); - int div, ret; - - div = rcar_pwm_get_clock_division(rp, period_ns); - if (div < 0) - return div; - - /* - * Let the core driver set pwm->period if disabled and duty_ns == 0. - * But, this driver should prevent to set the new duty_ns if current - * duty_cycle is not set - */ - if (!pwm_is_enabled(pwm) && !duty_ns && !pwm->state.duty_cycle) - return 0; - - rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR); - - ret = rcar_pwm_set_counter(rp, div, duty_ns, period_ns); - if (!ret) - rcar_pwm_set_clock_control(rp, div); - - /* The SYNC should be set to 0 even if rcar_pwm_set_counter failed */ - rcar_pwm_update(rp, RCAR_PWMCR_SYNC, 0, RCAR_PWMCR); - - return ret; + pm_runtime_put(pwmchip_parent(chip)); } -static int rcar_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) +static int rcar_pwm_enable(struct rcar_pwm_chip *rp) { - struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); u32 value; /* Don't enable the PWM device if CYC0 or PH0 is 0 */ @@ -185,34 +156,63 @@ static int rcar_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) return 0; } -static void rcar_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) +static void rcar_pwm_disable(struct rcar_pwm_chip *rp) +{ + rcar_pwm_update(rp, RCAR_PWMCR_EN0, 0, RCAR_PWMCR); +} + +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); + int div, ret; - rcar_pwm_update(rp, RCAR_PWMCR_EN0, 0, RCAR_PWMCR); + /* This HW/driver only supports normal polarity */ + if (state->polarity != PWM_POLARITY_NORMAL) + return -EINVAL; + + if (!state->enabled) { + rcar_pwm_disable(rp); + return 0; + } + + div = rcar_pwm_get_clock_division(rp, state->period); + if (div < 0) + return div; + + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR); + + ret = rcar_pwm_set_counter(rp, div, state->duty_cycle, state->period); + if (!ret) + rcar_pwm_set_clock_control(rp, div); + + /* The SYNC should be set to 0 even if rcar_pwm_set_counter failed */ + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, 0, RCAR_PWMCR); + + if (!ret) + ret = rcar_pwm_enable(rp); + + return ret; } static const struct pwm_ops rcar_pwm_ops = { .request = rcar_pwm_request, .free = rcar_pwm_free, - .config = rcar_pwm_config, - .enable = rcar_pwm_enable, - .disable = rcar_pwm_disable, - .owner = THIS_MODULE, + .apply = rcar_pwm_apply, }; static int rcar_pwm_probe(struct platform_device *pdev) { + struct pwm_chip *chip; struct rcar_pwm_chip *rcar_pwm; - struct resource *res; int ret; - rcar_pwm = devm_kzalloc(&pdev->dev, sizeof(*rcar_pwm), GFP_KERNEL); - if (rcar_pwm == NULL) - return -ENOMEM; + chip = devm_pwmchip_alloc(&pdev->dev, 1, sizeof(*rcar_pwm)); + if (IS_ERR(chip)) + return PTR_ERR(chip); + rcar_pwm = to_rcar_pwm_chip(chip); - res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - rcar_pwm->base = devm_ioremap_resource(&pdev->dev, res); + rcar_pwm->base = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(rcar_pwm->base)) return PTR_ERR(rcar_pwm->base); @@ -222,31 +222,29 @@ static int rcar_pwm_probe(struct platform_device *pdev) return PTR_ERR(rcar_pwm->clk); } - platform_set_drvdata(pdev, rcar_pwm); + chip->ops = &rcar_pwm_ops; - rcar_pwm->chip.dev = &pdev->dev; - rcar_pwm->chip.ops = &rcar_pwm_ops; - rcar_pwm->chip.base = -1; - rcar_pwm->chip.npwm = 1; + platform_set_drvdata(pdev, chip); - ret = pwmchip_add(&rcar_pwm->chip); + pm_runtime_enable(&pdev->dev); + + ret = pwmchip_add(chip); if (ret < 0) { dev_err(&pdev->dev, "failed to register PWM chip: %d\n", ret); + pm_runtime_disable(&pdev->dev); return ret; } - pm_runtime_enable(&pdev->dev); - return 0; } -static int rcar_pwm_remove(struct platform_device *pdev) +static void rcar_pwm_remove(struct platform_device *pdev) { - struct rcar_pwm_chip *rcar_pwm = platform_get_drvdata(pdev); + struct pwm_chip *chip = platform_get_drvdata(pdev); - pm_runtime_disable(&pdev->dev); + pwmchip_remove(chip); - return pwmchip_remove(&rcar_pwm->chip); + pm_runtime_disable(&pdev->dev); } static const struct of_device_id rcar_pwm_of_table[] = { @@ -255,53 +253,12 @@ static const struct of_device_id rcar_pwm_of_table[] = { }; MODULE_DEVICE_TABLE(of, rcar_pwm_of_table); -#ifdef CONFIG_PM_SLEEP -static struct pwm_device *rcar_pwm_dev_to_pwm_dev(struct device *dev) -{ - struct rcar_pwm_chip *rcar_pwm = dev_get_drvdata(dev); - struct pwm_chip *chip = &rcar_pwm->chip; - - return &chip->pwms[0]; -} - -static int rcar_pwm_suspend(struct device *dev) -{ - struct pwm_device *pwm = rcar_pwm_dev_to_pwm_dev(dev); - - if (!test_bit(PWMF_REQUESTED, &pwm->flags)) - return 0; - - pm_runtime_put(dev); - - return 0; -} - -static int rcar_pwm_resume(struct device *dev) -{ - struct pwm_device *pwm = rcar_pwm_dev_to_pwm_dev(dev); - - if (!test_bit(PWMF_REQUESTED, &pwm->flags)) - return 0; - - pm_runtime_get_sync(dev); - - rcar_pwm_config(pwm->chip, pwm, pwm->state.duty_cycle, - pwm->state.period); - if (pwm_is_enabled(pwm)) - rcar_pwm_enable(pwm->chip, pwm); - - return 0; -} -#endif /* CONFIG_PM_SLEEP */ -static SIMPLE_DEV_PM_OPS(rcar_pwm_pm_ops, rcar_pwm_suspend, rcar_pwm_resume); - static struct platform_driver rcar_pwm_driver = { .probe = rcar_pwm_probe, .remove = rcar_pwm_remove, .driver = { .name = "pwm-rcar", - .pm = &rcar_pwm_pm_ops, - .of_match_table = of_match_ptr(rcar_pwm_of_table), + .of_match_table = rcar_pwm_of_table, } }; module_platform_driver(rcar_pwm_driver); |