diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/plat-s3c/pwm.c | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c/pwm.c b/arch/arm/plat-s3c/pwm.c index 4fdc5b307fd..2a5275d98ca 100644 --- a/arch/arm/plat-s3c/pwm.c +++ b/arch/arm/plat-s3c/pwm.c @@ -21,6 +21,8 @@ #include <mach/irqs.h> #include <mach/map.h> +#include <mach/gpio.h> +#include <mach/regs-gpio.h> #include <plat/devs.h> #include <plat/regs-timer.h> @@ -40,6 +42,10 @@ struct pwm_device { unsigned char running; unsigned char use_count; unsigned char pwm_id; + + /* Used for saving state during suspend */ + unsigned long tcon; + unsigned char routed_to_gpio:1; }; #define pwm_dbg(_pwm, msg...) dev_dbg(&(_pwm)->pdev->dev, msg) @@ -130,6 +136,7 @@ void pwm_free(struct pwm_device *pwm) EXPORT_SYMBOL(pwm_free); +#define pwm_tcon_mask(pwm) (0xf << (pwm->tcon_base)) #define pwm_tcon_start(pwm) (1 << (pwm->tcon_base + 0)) #define pwm_tcon_invert(pwm) (1 << (pwm->tcon_base + 2)) #define pwm_tcon_autoreload(pwm) (1 << (pwm->tcon_base + 3)) @@ -379,10 +386,75 @@ static int s3c_pwm_remove(struct platform_device *pdev) return 0; } +#ifdef CONFIG_PM + +static int s3c_pwm_suspend(struct device *dev) +{ + struct pwm_device *pwm = dev_get_drvdata(dev); + unsigned int gpio_cfg = s3c2410_gpio_getcfg(S3C2410_GPB(pwm->pwm_id)); + + /* During suspend the pwm registers are reseted. If the invert bit is not + * set the output of TOUTn is high when the pwm is not active. In order to + * prevent spurious high output on the gpio at resume time, we stop routing + * the pwm signal to the gpio until tcon has been restored. */ + if (gpio_cfg == S3C2410_GPIO_SFN2) { + s3c2410_gpio_cfgpin(S3C2410_GPB(pwm->pwm_id), S3C2410_GPIO_INPUT); + pwm->routed_to_gpio = 1; + } else { + pwm->routed_to_gpio = 0; + } + + pwm->tcon = __raw_readl(S3C2410_TCON); + + return 0; +} + +static int s3c_pwm_resume(struct device *dev) +{ + struct pwm_device *pwm = dev_get_drvdata(dev); + unsigned long flags; + unsigned long tcon; + int duty_ns, period_ns; + + duty_ns = pwm->duty_ns; + period_ns = pwm->period_ns; + pwm->duty_ns = -1; + pwm->period_ns = -1; + pwm_config(pwm, duty_ns, period_ns); + + local_irq_save(flags); + tcon = __raw_readl(S3C2410_TCON); + tcon = __raw_readl(S3C2410_TCON); + tcon &= ~pwm_tcon_mask(pwm); + tcon |= pwm->tcon; + __raw_writel(tcon, S3C2410_TCON); + local_irq_restore(flags); + + if (pwm->routed_to_gpio) + s3c2410_gpio_cfgpin(S3C2410_GPB(pwm->pwm_id), S3C2410_GPIO_SFN2); + + return 0; +} + +struct dev_pm_ops s3c_pwm_pm_ops = { + .suspend = s3c_pwm_suspend, + .resume = s3c_pwm_resume, + .freeze = s3c_pwm_suspend, + .thaw = s3c_pwm_resume, +}; + +#define S3C_PWM_PM_OPS (&s3c_pwm_pm_ops) + +#else +#define S3C_PWM_PM_OPS NULL +#endif + + static struct platform_driver s3c_pwm_driver = { .driver = { .name = "s3c24xx-pwm", .owner = THIS_MODULE, + .pm = S3C_PWM_PM_OPS, }, .probe = s3c_pwm_probe, .remove = __devexit_p(s3c_pwm_remove), |