diff options
Diffstat (limited to 'arch/arm/plat-s3c/pwm.c')
| -rw-r--r-- | arch/arm/plat-s3c/pwm.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c/pwm.c b/arch/arm/plat-s3c/pwm.c new file mode 100644 index 00000000000..250bd2bc9b8 --- /dev/null +++ b/arch/arm/plat-s3c/pwm.c @@ -0,0 +1,288 @@ +/* + * arch/arm/plat-s3c/pwm.c + * + * Copyright (c) by Javi Roman <javiroman@kernel-labs.org> + * for the Openmoko Project. + * + * S3C2410A SoC PWM support + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/clk.h> +#include <linux/device.h> +#include <mach/hardware.h> +#include <plat/regs-timer.h> +#include <plat/pwm.h> +#include <asm/io.h> + +#ifdef CONFIG_PM + static unsigned long standby_reg_tcon; + static unsigned long standby_reg_tcfg0; + static unsigned long standby_reg_tcfg1; +#endif + +int s3c2410_pwm_disable(struct s3c2410_pwm *pwm) +{ + unsigned long tcon; + + /* stop timer */ + tcon = __raw_readl(S3C2410_TCON); + tcon &= 0xffffff00; + __raw_writel(tcon, S3C2410_TCON); + + clk_disable(pwm->pclk); + clk_put(pwm->pclk); + + return 0; +} +EXPORT_SYMBOL_GPL(s3c2410_pwm_disable); + +int s3c2410_pwm_init(struct s3c2410_pwm *pwm) +{ + pwm->pclk = clk_get(NULL, "timers"); + if (IS_ERR(pwm->pclk)) + return PTR_ERR(pwm->pclk); + + clk_enable(pwm->pclk); + pwm->pclk_rate = clk_get_rate(pwm->pclk); + return 0; +} +EXPORT_SYMBOL_GPL(s3c2410_pwm_init); + +int s3c2410_pwm_enable(struct s3c2410_pwm *pwm) +{ + unsigned long tcfg0, tcfg1, tcnt, tcmp; + + /* control registers bits */ + tcfg1 = __raw_readl(S3C2410_TCFG1); + tcfg0 = __raw_readl(S3C2410_TCFG0); + + /* divider & scaler slection */ + switch (pwm->timerid) { + case PWM0: + tcfg1 &= ~S3C2410_TCFG1_MUX0_MASK; + tcfg0 &= ~S3C2410_TCFG_PRESCALER0_MASK; + break; + case PWM1: + tcfg1 &= ~S3C2410_TCFG1_MUX1_MASK; + tcfg0 &= ~S3C2410_TCFG_PRESCALER0_MASK; + break; + case PWM2: + tcfg1 &= ~S3C2410_TCFG1_MUX2_MASK; + tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK; + break; + case PWM3: + tcfg1 &= ~S3C2410_TCFG1_MUX3_MASK; + tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK; + break; + case PWM4: + /* timer four is not capable of doing PWM */ + break; + default: + clk_disable(pwm->pclk); + clk_put(pwm->pclk); + return -1; + } + + /* divider & scaler values */ + tcfg1 |= pwm->divider; + __raw_writel(tcfg1, S3C2410_TCFG1); + + switch (pwm->timerid) { + case PWM0: + case PWM1: + tcfg0 |= pwm->prescaler; + __raw_writel(tcfg0, S3C2410_TCFG0); + break; + default: + if ((tcfg0 | pwm->prescaler) != tcfg0) { + printk(KERN_WARNING "not changing prescaler of PWM %u," + " since it's shared with timer4 (clock tick)\n", + pwm->timerid); + } + break; + } + + /* timer count and compare buffer initial values */ + tcnt = pwm->counter; + tcmp = pwm->comparer; + + __raw_writel(tcnt, S3C2410_TCNTB(pwm->timerid)); + __raw_writel(tcmp, S3C2410_TCMPB(pwm->timerid)); + + /* ensure timer is stopped */ + s3c2410_pwm_stop(pwm); + + return 0; +} +EXPORT_SYMBOL_GPL(s3c2410_pwm_enable); + +int s3c2410_pwm_start(struct s3c2410_pwm *pwm) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + switch (pwm->timerid) { + case PWM0: + tcon |= S3C2410_TCON_T0START; + tcon &= ~S3C2410_TCON_T0MANUALUPD; + break; + case PWM1: + tcon |= S3C2410_TCON_T1START; + tcon &= ~S3C2410_TCON_T1MANUALUPD; + break; + case PWM2: + tcon |= S3C2410_TCON_T2START; + tcon &= ~S3C2410_TCON_T2MANUALUPD; + break; + case PWM3: + tcon |= S3C2410_TCON_T3START; + tcon &= ~S3C2410_TCON_T3MANUALUPD; + break; + case PWM4: + /* timer four is not capable of doing PWM */ + default: + return -ENODEV; + } + + __raw_writel(tcon, S3C2410_TCON); + + return 0; +} +EXPORT_SYMBOL_GPL(s3c2410_pwm_start); + +int s3c2410_pwm_stop(struct s3c2410_pwm *pwm) +{ + unsigned long tcon; + + tcon = __raw_readl(S3C2410_TCON); + + switch (pwm->timerid) { + case PWM0: + tcon &= ~0x00000000; + tcon |= S3C2410_TCON_T0RELOAD; + tcon |= S3C2410_TCON_T0MANUALUPD; + break; + case PWM1: + tcon &= ~0x00000080; + tcon |= S3C2410_TCON_T1RELOAD; + tcon |= S3C2410_TCON_T1MANUALUPD; + break; + case PWM2: + tcon &= ~0x00000800; + tcon |= S3C2410_TCON_T2RELOAD; + tcon |= S3C2410_TCON_T2MANUALUPD; + break; + case PWM3: + tcon &= ~0x00008000; + tcon |= S3C2410_TCON_T3RELOAD; + tcon |= S3C2410_TCON_T3MANUALUPD; + break; + case PWM4: + /* timer four is not capable of doing PWM */ + default: + return -ENODEV; + } + + __raw_writel(tcon, S3C2410_TCON); + + return 0; +} +EXPORT_SYMBOL_GPL(s3c2410_pwm_stop); + +int s3c2410_pwm_duty_cycle(int reg_value, struct s3c2410_pwm *pwm) +{ + __raw_writel(reg_value, S3C2410_TCMPB(pwm->timerid)); + + return 0; +} +EXPORT_SYMBOL_GPL(s3c2410_pwm_duty_cycle); + +int s3c2410_pwm_dumpregs(void) +{ + printk(KERN_INFO "TCON: %08lx, TCFG0: %08lx, TCFG1: %08lx\n", + (unsigned long) __raw_readl(S3C2410_TCON), + (unsigned long) __raw_readl(S3C2410_TCFG0), + (unsigned long) __raw_readl(S3C2410_TCFG1)); + + return 0; +} +EXPORT_SYMBOL_GPL(s3c2410_pwm_dumpregs); + +static int __init s3c24xx_pwm_probe(struct platform_device *pdev) +{ + struct s3c24xx_pwm_platform_data *pdata = pdev->dev.platform_data; + + dev_info(&pdev->dev, "s3c24xx_pwm is registered \n"); + + /* if platform was interested, give him a chance to register + * platform devices that switch power with us as the parent + * at registration time -- ensures suspend / resume ordering + */ + if (pdata) + if (pdata->attach_child_devices) + (pdata->attach_child_devices)(&pdev->dev); + + return 0; +} + +#ifdef CONFIG_PM +static int s3c24xx_pwm_suspend(struct platform_device *pdev, pm_message_t state) +{ + /* PWM config should be kept in suspending */ + standby_reg_tcon = __raw_readl(S3C2410_TCON); + standby_reg_tcfg0 = __raw_readl(S3C2410_TCFG0); + standby_reg_tcfg1 = __raw_readl(S3C2410_TCFG1); + + return 0; +} + +static int s3c24xx_pwm_resume(struct platform_device *pdev) +{ + __raw_writel(standby_reg_tcon, S3C2410_TCON); + __raw_writel(standby_reg_tcfg0, S3C2410_TCFG0); + __raw_writel(standby_reg_tcfg1, S3C2410_TCFG1); + + return 0; +} +#else +#define s3c24xx_pwm_suspend NULL +#define s3c24xx_pwm_resume NULL +#endif + +static struct platform_driver s3c24xx_pwm_driver = { + .driver = { + .name = "s3c24xx_pwm", + .owner = THIS_MODULE, + }, + .probe = s3c24xx_pwm_probe, + .suspend = s3c24xx_pwm_suspend, + .resume = s3c24xx_pwm_resume, +}; + +static int __init s3c24xx_pwm_init(void) +{ + return platform_driver_register(&s3c24xx_pwm_driver); +} + +static void __exit s3c24xx_pwm_exit(void) +{ +} + +MODULE_AUTHOR("Javi Roman <javiroman@kernel-labs.org>"); +MODULE_LICENSE("GPL"); + +module_init(s3c24xx_pwm_init); +module_exit(s3c24xx_pwm_exit); |