diff options
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/core.c | 2 | ||||
| -rw-r--r-- | drivers/pwm/pwm-atmel-hlcdc.c | 4 | ||||
| -rw-r--r-- | drivers/pwm/pwm-img.c | 76 | ||||
| -rw-r--r-- | drivers/pwm/pwm-mxs.c | 8 | ||||
| -rw-r--r-- | drivers/pwm/pwm-pca9685.c | 2 | ||||
| -rw-r--r-- | drivers/pwm/pwm-samsung.c | 32 |
6 files changed, 107 insertions, 17 deletions
diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index 810aef3f4c3e..ba34c7d89042 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -573,7 +573,7 @@ EXPORT_SYMBOL_GPL(of_pwm_get); * @table: array of consumers to register * @num: number of consumers in table */ -void __init pwm_add_table(struct pwm_lookup *table, size_t num) +void pwm_add_table(struct pwm_lookup *table, size_t num) { mutex_lock(&pwm_lookup_lock); diff --git a/drivers/pwm/pwm-atmel-hlcdc.c b/drivers/pwm/pwm-atmel-hlcdc.c index 522f7075bb1a..fa5feaba25a5 100644 --- a/drivers/pwm/pwm-atmel-hlcdc.c +++ b/drivers/pwm/pwm-atmel-hlcdc.c @@ -225,6 +225,10 @@ static const struct of_device_id atmel_hlcdc_dt_ids[] = { .compatible = "atmel,sama5d3-hlcdc", .data = &atmel_hlcdc_pwm_sama5d3_errata, }, + { + .compatible = "atmel,sama5d4-hlcdc", + .data = &atmel_hlcdc_pwm_sama5d3_errata, + }, { /* sentinel */ }, }; diff --git a/drivers/pwm/pwm-img.c b/drivers/pwm/pwm-img.c index 476171a768d6..8a029f9bc18c 100644 --- a/drivers/pwm/pwm-img.c +++ b/drivers/pwm/pwm-img.c @@ -16,6 +16,7 @@ #include <linux/mfd/syscon.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/pwm.h> #include <linux/regmap.h> @@ -38,7 +39,22 @@ #define PERIP_PWM_PDM_CONTROL_CH_MASK 0x1 #define PERIP_PWM_PDM_CONTROL_CH_SHIFT(ch) ((ch) * 4) -#define MAX_TMBASE_STEPS 65536 +/* + * PWM period is specified with a timebase register, + * in number of step periods. The PWM duty cycle is also + * specified in step periods, in the [0, $timebase] range. + * In other words, the timebase imposes the duty cycle + * resolution. Therefore, let's constraint the timebase to + * a minimum value to allow a sane range of duty cycle values. + * Imposing a minimum timebase, will impose a maximum PWM frequency. + * + * The value chosen is completely arbitrary. + */ +#define MIN_TMBASE_STEPS 16 + +struct img_pwm_soc_data { + u32 max_timebase; +}; struct img_pwm_chip { struct device *dev; @@ -47,6 +63,9 @@ struct img_pwm_chip { struct clk *sys_clk; void __iomem *base; struct regmap *periph_regs; + int max_period_ns; + int min_period_ns; + const struct img_pwm_soc_data *data; }; static inline struct img_pwm_chip *to_img_pwm_chip(struct pwm_chip *chip) @@ -72,24 +91,31 @@ static int img_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, u32 val, div, duty, timebase; unsigned long mul, output_clk_hz, input_clk_hz; struct img_pwm_chip *pwm_chip = to_img_pwm_chip(chip); + unsigned int max_timebase = pwm_chip->data->max_timebase; + + if (period_ns < pwm_chip->min_period_ns || + period_ns > pwm_chip->max_period_ns) { + dev_err(chip->dev, "configured period not in range\n"); + return -ERANGE; + } input_clk_hz = clk_get_rate(pwm_chip->pwm_clk); output_clk_hz = DIV_ROUND_UP(NSEC_PER_SEC, period_ns); mul = DIV_ROUND_UP(input_clk_hz, output_clk_hz); - if (mul <= MAX_TMBASE_STEPS) { + if (mul <= max_timebase) { div = PWM_CTRL_CFG_NO_SUB_DIV; timebase = DIV_ROUND_UP(mul, 1); - } else if (mul <= MAX_TMBASE_STEPS * 8) { + } else if (mul <= max_timebase * 8) { div = PWM_CTRL_CFG_SUB_DIV0; timebase = DIV_ROUND_UP(mul, 8); - } else if (mul <= MAX_TMBASE_STEPS * 64) { + } else if (mul <= max_timebase * 64) { div = PWM_CTRL_CFG_SUB_DIV1; timebase = DIV_ROUND_UP(mul, 64); - } else if (mul <= MAX_TMBASE_STEPS * 512) { + } else if (mul <= max_timebase * 512) { div = PWM_CTRL_CFG_SUB_DIV0_DIV1; timebase = DIV_ROUND_UP(mul, 512); - } else if (mul > MAX_TMBASE_STEPS * 512) { + } else if (mul > max_timebase * 512) { dev_err(chip->dev, "failed to configure timebase steps/divider value\n"); return -EINVAL; @@ -143,11 +169,27 @@ static const struct pwm_ops img_pwm_ops = { .owner = THIS_MODULE, }; +static const struct img_pwm_soc_data pistachio_pwm = { + .max_timebase = 255, +}; + +static const struct of_device_id img_pwm_of_match[] = { + { + .compatible = "img,pistachio-pwm", + .data = &pistachio_pwm, + }, + { } +}; +MODULE_DEVICE_TABLE(of, img_pwm_of_match); + static int img_pwm_probe(struct platform_device *pdev) { int ret; + u64 val; + unsigned long clk_rate; struct resource *res; struct img_pwm_chip *pwm; + const struct of_device_id *of_dev_id; pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL); if (!pwm) @@ -160,6 +202,11 @@ static int img_pwm_probe(struct platform_device *pdev) if (IS_ERR(pwm->base)) return PTR_ERR(pwm->base); + of_dev_id = of_match_device(img_pwm_of_match, &pdev->dev); + if (!of_dev_id) + return -ENODEV; + pwm->data = of_dev_id->data; + pwm->periph_regs = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "img,cr-periph"); if (IS_ERR(pwm->periph_regs)) @@ -189,6 +236,17 @@ static int img_pwm_probe(struct platform_device *pdev) goto disable_sysclk; } + clk_rate = clk_get_rate(pwm->pwm_clk); + + /* The maximum input clock divider is 512 */ + val = (u64)NSEC_PER_SEC * 512 * pwm->data->max_timebase; + do_div(val, clk_rate); + pwm->max_period_ns = val; + + val = (u64)NSEC_PER_SEC * MIN_TMBASE_STEPS; + do_div(val, clk_rate); + pwm->min_period_ns = val; + pwm->chip.dev = &pdev->dev; pwm->chip.ops = &img_pwm_ops; pwm->chip.base = -1; @@ -228,12 +286,6 @@ static int img_pwm_remove(struct platform_device *pdev) return pwmchip_remove(&pwm_chip->chip); } -static const struct of_device_id img_pwm_of_match[] = { - { .compatible = "img,pistachio-pwm", }, - { } -}; -MODULE_DEVICE_TABLE(of, img_pwm_of_match); - static struct platform_driver img_pwm_driver = { .driver = { .name = "img-pwm", diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c index f75ecb09d97d..b430811e14f5 100644 --- a/drivers/pwm/pwm-mxs.c +++ b/drivers/pwm/pwm-mxs.c @@ -35,6 +35,10 @@ #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 +}; + struct mxs_pwm_chip { struct pwm_chip chip; struct clk *clk; @@ -54,13 +58,13 @@ static int mxs_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, rate = clk_get_rate(mxs->clk); while (1) { - c = rate / (1 << div); + c = rate / cdiv[div]; c = c * period_ns; do_div(c, 1000000000); if (c < PERIOD_PERIOD_MAX) break; div++; - if (div > PERIOD_CDIV_MAX) + if (div >= PERIOD_CDIV_MAX) return -EINVAL; } diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 3fb775ded0df..34b5c275a92a 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -202,7 +202,7 @@ static const struct pwm_ops pca9685_pwm_ops = { .owner = THIS_MODULE, }; -static struct regmap_config pca9685_regmap_i2c_config = { +static const struct regmap_config pca9685_regmap_i2c_config = { .reg_bits = 8, .val_bits = 8, .max_register = PCA9685_NUMREGS, diff --git a/drivers/pwm/pwm-samsung.c b/drivers/pwm/pwm-samsung.c index 3e9b5835a4af..ff201e1b9219 100644 --- a/drivers/pwm/pwm-samsung.c +++ b/drivers/pwm/pwm-samsung.c @@ -269,12 +269,31 @@ static void pwm_samsung_disable(struct pwm_chip *chip, struct pwm_device *pwm) spin_unlock_irqrestore(&samsung_pwm_lock, flags); } +static void pwm_samsung_manual_update(struct samsung_pwm_chip *chip, + struct pwm_device *pwm) +{ + unsigned int tcon_chan = to_tcon_channel(pwm->hwpwm); + u32 tcon; + unsigned long flags; + + spin_lock_irqsave(&samsung_pwm_lock, flags); + + tcon = readl(chip->base + REG_TCON); + tcon |= TCON_MANUALUPDATE(tcon_chan); + writel(tcon, chip->base + REG_TCON); + + tcon &= ~TCON_MANUALUPDATE(tcon_chan); + writel(tcon, chip->base + REG_TCON); + + spin_unlock_irqrestore(&samsung_pwm_lock, flags); +} + static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, int duty_ns, int period_ns) { struct samsung_pwm_chip *our_chip = to_samsung_pwm_chip(chip); struct samsung_pwm_channel *chan = pwm_get_chip_data(pwm); - u32 tin_ns = chan->tin_ns, tcnt, tcmp; + u32 tin_ns = chan->tin_ns, tcnt, tcmp, oldtcmp; /* * We currently avoid using 64bit arithmetic by using the @@ -288,6 +307,7 @@ static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, return 0; tcnt = readl(our_chip->base + REG_TCNTB(pwm->hwpwm)); + oldtcmp = readl(our_chip->base + REG_TCMPB(pwm->hwpwm)); /* We need tick count for calculation, not last tick. */ ++tcnt; @@ -335,6 +355,16 @@ static int pwm_samsung_config(struct pwm_chip *chip, struct pwm_device *pwm, writel(tcnt, our_chip->base + REG_TCNTB(pwm->hwpwm)); writel(tcmp, our_chip->base + REG_TCMPB(pwm->hwpwm)); + /* + * In case the PWM is currently at 100% duty cycle, force a manual + * update to prevent the signal staying high if the PWM is disabled + * shortly afer this update (before it autoreloaded the new values). + */ + if (oldtcmp == (u32) -1) { + dev_dbg(our_chip->chip.dev, "Forcing manual update"); + pwm_samsung_manual_update(our_chip, pwm); + } + chan->period_ns = period_ns; chan->tin_ns = tin_ns; chan->duty_ns = duty_ns; |
