diff options
Diffstat (limited to 'drivers/pwm/pwm-lpc32xx.c')
| -rw-r--r-- | drivers/pwm/pwm-lpc32xx.c | 66 |
1 files changed, 50 insertions, 16 deletions
diff --git a/drivers/pwm/pwm-lpc32xx.c b/drivers/pwm/pwm-lpc32xx.c index adb87f0c163..9dc0f9d42bf 100644 --- a/drivers/pwm/pwm-lpc32xx.c +++ b/drivers/pwm/pwm-lpc32xx.c @@ -37,6 +37,7 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); unsigned long long c; int period_cycles, duty_cycles; + u32 val; c = clk_get_rate(lpc32xx->clk) / 256; c = c * period_ns; @@ -49,12 +50,29 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, c = 0; /* 0 set division by 256 */ period_cycles = c; + /* The duty-cycle value is as follows: + * + * DUTY-CYCLE HIGH LEVEL + * 1 99.9% + * 25 90.0% + * 128 50.0% + * 220 10.0% + * 255 0.1% + * 0 0.0% + * + * In other words, the register value is duty-cycle % 256 with + * duty-cycle in the range 1-256. + */ c = 256 * duty_ns; do_div(c, period_ns); - duty_cycles = c; + if (c > 255) + c = 255; + duty_cycles = 256 - c; - writel(PWM_ENABLE | PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles), - lpc32xx->base + (pwm->hwpwm << 2)); + val = readl(lpc32xx->base + (pwm->hwpwm << 2)); + val &= ~0xFFFF; + val |= PWM_RELOADV(period_cycles) | PWM_DUTY(duty_cycles); + writel(val, lpc32xx->base + (pwm->hwpwm << 2)); return 0; } @@ -62,15 +80,29 @@ static int lpc32xx_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, static int lpc32xx_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) { struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); + u32 val; + int ret; + + ret = clk_enable(lpc32xx->clk); + if (ret) + return ret; + + val = readl(lpc32xx->base + (pwm->hwpwm << 2)); + val |= PWM_ENABLE; + writel(val, lpc32xx->base + (pwm->hwpwm << 2)); - return clk_enable(lpc32xx->clk); + return 0; } static void lpc32xx_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) { struct lpc32xx_pwm_chip *lpc32xx = to_lpc32xx_pwm_chip(chip); + u32 val; + + val = readl(lpc32xx->base + (pwm->hwpwm << 2)); + val &= ~PWM_ENABLE; + writel(val, lpc32xx->base + (pwm->hwpwm << 2)); - writel(0, lpc32xx->base + (pwm->hwpwm << 2)); clk_disable(lpc32xx->clk); } @@ -92,12 +124,9 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) - return -EINVAL; - - lpc32xx->base = devm_request_and_ioremap(&pdev->dev, res); - if (!lpc32xx->base) - return -EADDRNOTAVAIL; + lpc32xx->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(lpc32xx->base)) + return PTR_ERR(lpc32xx->base); lpc32xx->clk = devm_clk_get(&pdev->dev, NULL); if (IS_ERR(lpc32xx->clk)) @@ -106,6 +135,7 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev) lpc32xx->chip.dev = &pdev->dev; lpc32xx->chip.ops = &lpc32xx_pwm_ops; lpc32xx->chip.npwm = 2; + lpc32xx->chip.base = -1; ret = pwmchip_add(&lpc32xx->chip); if (ret < 0) { @@ -118,15 +148,18 @@ static int lpc32xx_pwm_probe(struct platform_device *pdev) return 0; } -static int __devexit lpc32xx_pwm_remove(struct platform_device *pdev) +static int lpc32xx_pwm_remove(struct platform_device *pdev) { struct lpc32xx_pwm_chip *lpc32xx = platform_get_drvdata(pdev); + unsigned int i; + + for (i = 0; i < lpc32xx->chip.npwm; i++) + pwm_disable(&lpc32xx->chip.pwms[i]); - clk_disable(lpc32xx->clk); return pwmchip_remove(&lpc32xx->chip); } -static struct of_device_id lpc32xx_pwm_dt_ids[] = { +static const struct of_device_id lpc32xx_pwm_dt_ids[] = { { .compatible = "nxp,lpc3220-pwm", }, { /* sentinel */ } }; @@ -135,10 +168,11 @@ MODULE_DEVICE_TABLE(of, lpc32xx_pwm_dt_ids); static struct platform_driver lpc32xx_pwm_driver = { .driver = { .name = "lpc32xx-pwm", - .of_match_table = of_match_ptr(lpc32xx_pwm_dt_ids), + .owner = THIS_MODULE, + .of_match_table = lpc32xx_pwm_dt_ids, }, .probe = lpc32xx_pwm_probe, - .remove = __devexit_p(lpc32xx_pwm_remove), + .remove = lpc32xx_pwm_remove, }; module_platform_driver(lpc32xx_pwm_driver); |
