diff options
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/plat-s3c24xx/Kconfig | 7 | ||||
| -rw-r--r-- | arch/arm/plat-s3c24xx/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/plat-s3c24xx/devs.c | 100 | ||||
| -rw-r--r-- | arch/arm/plat-s3c24xx/pwm.c | 402 |
4 files changed, 410 insertions, 100 deletions
diff --git a/arch/arm/plat-s3c24xx/Kconfig b/arch/arm/plat-s3c24xx/Kconfig index 1521f1ce3b2..5e28c217b8c 100644 --- a/arch/arm/plat-s3c24xx/Kconfig +++ b/arch/arm/plat-s3c24xx/Kconfig @@ -21,6 +21,13 @@ config CPU_S3C244X help Support for S3C2440 and S3C2442 Samsung Mobile CPU based systems. +config S3C24XX_PWM + bool "PWM device support" + select HAVE_PWM + help + Support for exporting the PWM timer blocks via the pwm device + system. + config PM_SIMTEC bool help diff --git a/arch/arm/plat-s3c24xx/Makefile b/arch/arm/plat-s3c24xx/Makefile index c925d577fef..d82767b2b83 100644 --- a/arch/arm/plat-s3c24xx/Makefile +++ b/arch/arm/plat-s3c24xx/Makefile @@ -29,5 +29,6 @@ obj-$(CONFIG_CPU_S3C244X) += s3c244x-clock.o obj-$(CONFIG_PM_SIMTEC) += pm-simtec.o obj-$(CONFIG_PM) += pm.o obj-$(CONFIG_PM) += sleep.o +obj-$(CONFIG_HAVE_PWM) += pwm.o obj-$(CONFIG_S3C2410_DMA) += dma.o obj-$(CONFIG_MACH_SMDK) += common-smdk.o diff --git a/arch/arm/plat-s3c24xx/devs.c b/arch/arm/plat-s3c24xx/devs.c index e546e933b3f..eea3b32ff79 100644 --- a/arch/arm/plat-s3c24xx/devs.c +++ b/arch/arm/plat-s3c24xx/devs.c @@ -495,106 +495,6 @@ struct platform_device s3c_device_spi1 = { EXPORT_SYMBOL(s3c_device_spi1); -/* pwm timer blocks */ - -static struct resource s3c_timer0_resource[] = { - [0] = { - .start = S3C24XX_PA_TIMER + 0x0C, - .end = S3C24XX_PA_TIMER + 0x0C + 0xB, - .flags = IORESOURCE_MEM, - }, - [1] = { - .start = IRQ_TIMER0, - .end = IRQ_TIMER0, - .flags = IORESOURCE_IRQ, - } - -}; - -struct platform_device s3c_device_timer0 = { - .name = "s3c2410-timer", - .id = 0, - .num_resources = ARRAY_SIZE(s3c_timer0_resource), - .resource = s3c_timer0_resource, -}; - -EXPORT_SYMBOL(s3c_device_timer0); - -/* timer 1 */ - -static struct resource s3c_timer1_resource[] = { - [0] = { - .start = S3C24XX_PA_TIMER + 0x18, - .end = S3C24XX_PA_TIMER + 0x23, - .flags = IORESOURCE_MEM, - }, - [1] = { - .start = IRQ_TIMER1, - .end = IRQ_TIMER1, - .flags = IORESOURCE_IRQ, - } - -}; - -struct platform_device s3c_device_timer1 = { - .name = "s3c2410-timer", - .id = 1, - .num_resources = ARRAY_SIZE(s3c_timer1_resource), - .resource = s3c_timer1_resource, -}; - -EXPORT_SYMBOL(s3c_device_timer1); - -/* timer 2 */ - -static struct resource s3c_timer2_resource[] = { - [0] = { - .start = S3C24XX_PA_TIMER + 0x24, - .end = S3C24XX_PA_TIMER + 0x2F, - .flags = IORESOURCE_MEM, - }, - [1] = { - .start = IRQ_TIMER2, - .end = IRQ_TIMER2, - .flags = IORESOURCE_IRQ, - } - -}; - -struct platform_device s3c_device_timer2 = { - .name = "s3c2410-timer", - .id = 2, - .num_resources = ARRAY_SIZE(s3c_timer2_resource), - .resource = s3c_timer2_resource, -}; - -EXPORT_SYMBOL(s3c_device_timer2); - -/* timer 3 */ - -static struct resource s3c_timer3_resource[] = { - [0] = { - .start = S3C24XX_PA_TIMER + 0x30, - .end = S3C24XX_PA_TIMER + 0x3B, - .flags = IORESOURCE_MEM, - }, - [1] = { - .start = IRQ_TIMER3, - .end = IRQ_TIMER3, - .flags = IORESOURCE_IRQ, - } - -}; - -struct platform_device s3c_device_timer3 = { - .name = "s3c2410-timer", - .id = 3, - .num_resources = ARRAY_SIZE(s3c_timer3_resource), - .resource = s3c_timer3_resource, -}; - -EXPORT_SYMBOL(s3c_device_timer3); - #ifdef CONFIG_CPU_S3C2440 /* Camif Controller */ diff --git a/arch/arm/plat-s3c24xx/pwm.c b/arch/arm/plat-s3c24xx/pwm.c new file mode 100644 index 00000000000..18c4bdc49a0 --- /dev/null +++ b/arch/arm/plat-s3c24xx/pwm.c @@ -0,0 +1,402 @@ +/* arch/arm/plat-s3c24xx/pwm.c + * + * Copyright (c) 2007 Ben Dooks + * Copyright (c) 2008 Simtec Electronics + * Ben Dooks <ben@simtec.co.uk>, <ben-linux@fluff.org> + * + * S3C24XX PWM device core + * + * 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. +*/ + +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/err.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/pwm.h> + +#include <asm/plat-s3c/regs-timer.h> + +struct pwm_device { + struct list_head list; + struct platform_device *pdev; + + struct clk *clk_div; + struct clk *clk; + const char *label; + + unsigned int period_ns; + unsigned int duty_ns; + + unsigned char tcon_base; + unsigned char running; + unsigned char use_count; + unsigned char pwm_id; +}; + +#define pwm_dbg(_pwm, msg...) dev_info(&(_pwm)->pdev->dev, msg) + +static struct clk *clk_scaler[2]; + +/* Standard setup for a timer block. */ + +#define TIMER_RESOURCE_SIZE (1) + +#define TIMER_RESOURCE(_tmr, _irq) \ + (struct resource [TIMER_RESOURCE_SIZE]) { \ + [0] = { \ + .start = _irq, \ + .end = _irq, \ + .flags = IORESOURCE_IRQ \ + } \ + } + +#define DEFINE_TIMER(_tmr_no, _irq) \ + .name = "s3c24xx-pwm", \ + .id = _tmr_no, \ + .num_resources = TIMER_RESOURCE_SIZE, \ + .resource = TIMER_RESOURCE(_tmr_no, _irq), \ + +/* since we already have an static mapping for the timer, we do not + * bother setting any IO resource for the base. + */ + +struct platform_device s3c_device_timer[] = { + [0] = { DEFINE_TIMER(0, IRQ_TIMER0) }, + [1] = { DEFINE_TIMER(1, IRQ_TIMER1) }, + [2] = { DEFINE_TIMER(2, IRQ_TIMER2) }, + [3] = { DEFINE_TIMER(3, IRQ_TIMER3) }, + [4] = { DEFINE_TIMER(4, IRQ_TIMER4) }, +}; + +static inline int pwm_is_tdiv(struct pwm_device *pwm) +{ + return clk_get_parent(pwm->clk) == pwm->clk_div; +} + +static DEFINE_MUTEX(pwm_lock); +static LIST_HEAD(pwm_list); + +struct pwm_device *pwm_request(int pwm_id, const char *label) +{ + struct pwm_device *pwm; + int found = 0; + + mutex_lock(&pwm_lock); + + list_for_each_entry(pwm, &pwm_list, list) { + if (pwm->pwm_id == pwm_id) { + found = 1; + break; + } + } + + if (found) { + if (pwm->use_count == 0) { + pwm->use_count = 1; + pwm->label = label; + } else + pwm = ERR_PTR(-EBUSY); + } else + pwm = ERR_PTR(-ENOENT); + + mutex_unlock(&pwm_lock); + return pwm; +} + +EXPORT_SYMBOL(pwm_request); + + +void pwm_free(struct pwm_device *pwm) +{ + mutex_lock(&pwm_lock); + + if (pwm->use_count) { + pwm->use_count--; + pwm->label = NULL; + } else + printk(KERN_ERR "PWM%d device already freed\n", pwm->pwm_id); + + mutex_unlock(&pwm_lock); +} + +EXPORT_SYMBOL(pwm_free); + +#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)) +#define pwm_tcon_manulupdate(pwm) (1 << (pwm->tcon_base + 1)) + +int pwm_enable(struct pwm_device *pwm) +{ + unsigned long flags; + unsigned long tcon; + + local_irq_save(flags); + + tcon = __raw_readl(S3C2410_TCON); + tcon |= pwm_tcon_start(pwm); + __raw_writel(tcon, S3C2410_TCON); + + local_irq_restore(flags); + + pwm->running = 1; + return 0; +} + +EXPORT_SYMBOL(pwm_enable); + +void pwm_disable(struct pwm_device *pwm) +{ + unsigned long flags; + unsigned long tcon; + + local_irq_save(flags); + + tcon = __raw_readl(S3C2410_TCON); + tcon &= ~pwm_tcon_start(pwm); + __raw_writel(tcon, S3C2410_TCON); + + local_irq_restore(flags); + + pwm->running = 0; +} + +EXPORT_SYMBOL(pwm_disable); + +unsigned long pwm_calc_tin(struct pwm_device *pwm, unsigned long freq) +{ + unsigned long tin_parent_rate; + unsigned int div; + + tin_parent_rate = clk_get_rate(clk_get_parent(pwm->clk_div)); + pwm_dbg(pwm, "tin parent at %lu\n", tin_parent_rate); + + for (div = 2; div <= 16; div *= 2) { + if ((tin_parent_rate / (div << 16)) < freq) + return tin_parent_rate / div; + } + + return tin_parent_rate / 16; +} + +#define NS_IN_HZ (1000000000UL) + +int pwm_config(struct pwm_device *pwm, int duty_ns, int period_ns) +{ + unsigned long tin_rate; + unsigned long tin_ns; + unsigned long period; + unsigned long flags; + unsigned long tcon; + unsigned long tcnt; + long tcmp; + + /* We currently avoid using 64bit arithmetic by using the + * fact that anything faster than 1Hz is easily representable + * by 32bits. */ + + if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ) + return -ERANGE; + + if (duty_ns > period_ns) + return -EINVAL; + + if (period_ns == pwm->period_ns && + duty_ns == pwm->duty_ns) + return 0; + + /* The TCMP and TCNT can be read without a lock, they're not + * shared between the timers. */ + + tcmp = __raw_readl(S3C2410_TCMPB(pwm->pwm_id)); + tcnt = __raw_readl(S3C2410_TCNTB(pwm->pwm_id)); + + period = NS_IN_HZ / period_ns; + + pwm_dbg(pwm, "duty_ns=%d, period_ns=%d (%lu)\n", + duty_ns, period_ns, period); + + /* Check to see if we are changing the clock rate of the PWM */ + + if (pwm->period_ns != period_ns) { + if (pwm_is_tdiv(pwm)) { + tin_rate = pwm_calc_tin(pwm, period); + clk_set_rate(pwm->clk_div, tin_rate); + } else + tin_rate = clk_get_rate(pwm->clk); + + pwm->period_ns = period_ns; + + pwm_dbg(pwm, "tin_rate=%lu\n", tin_rate); + + tin_ns = NS_IN_HZ / tin_rate; + tcnt = period_ns / tin_ns; + } else + tin_ns = NS_IN_HZ / clk_get_rate(pwm->clk); + + /* Note, counters count down */ + + tcmp = duty_ns / tin_ns; + tcmp = tcnt - tcmp; + + pwm_dbg(pwm, "tin_ns=%lu, tcmp=%ld/%lu\n", tin_ns, tcmp, tcnt); + + if (tcmp < 0) + tcmp = 0; + + /* Update the PWM register block. */ + + local_irq_save(flags); + + __raw_writel(tcmp, S3C2410_TCMPB(pwm->pwm_id)); + __raw_writel(tcnt, S3C2410_TCNTB(pwm->pwm_id)); + + tcon = __raw_readl(S3C2410_TCON); + tcon |= pwm_tcon_manulupdate(pwm); + tcon |= pwm_tcon_autoreload(pwm); + __raw_writel(tcon, S3C2410_TCON); + + tcon &= ~pwm_tcon_manulupdate(pwm); + __raw_writel(tcon, S3C2410_TCON); + + local_irq_restore(flags); + + return 0; +} + +EXPORT_SYMBOL(pwm_config); + +static int pwm_register(struct pwm_device *pwm) +{ + pwm->duty_ns = -1; + pwm->period_ns = -1; + + mutex_lock(&pwm_lock); + list_add_tail(&pwm->list, &pwm_list); + mutex_unlock(&pwm_lock); + + return 0; +} + +static int s3c_pwm_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct pwm_device *pwm; + unsigned long flags; + unsigned long tcon; + unsigned int id = pdev->id; + int ret; + + if (id == 4) { + dev_err(dev, "TIMER4 is currently not supported\n"); + return -ENXIO; + } + + pwm = kzalloc(sizeof(struct pwm_device), GFP_KERNEL); + if (pwm == NULL) { + dev_err(dev, "failed to allocate pwm_device\n"); + return -ENOMEM; + } + + pwm->pdev = pdev; + pwm->pwm_id = id; + + /* calculate base of control bits in TCON */ + pwm->tcon_base = id == 0 ? 0 : (id * 4) + 4; + + pwm->clk = clk_get(dev, "pwm-tin"); + if (IS_ERR(pwm->clk)) { + dev_err(dev, "failed to get pwm tin clk\n"); + ret = PTR_ERR(pwm->clk); + goto err_alloc; + } + + pwm->clk_div = clk_get(dev, "pwm-tdiv"); + if (IS_ERR(pwm->clk_div)) { + dev_err(dev, "failed to get pwm tdiv clk\n"); + ret = PTR_ERR(pwm->clk_div); + goto err_clk_tin; + } + + local_irq_save(flags); + + tcon = __raw_readl(S3C2410_TCON); + tcon |= pwm_tcon_invert(pwm); + __raw_writel(tcon, S3C2410_TCON); + + local_irq_restore(flags); + + + ret = pwm_register(pwm); + if (ret) { + dev_err(dev, "failed to register pwm\n"); + goto err_clk_tdiv; + } + + pwm_dbg(pwm, "config bits %02x\n", + (__raw_readl(S3C2410_TCON) >> pwm->tcon_base) & 0x0f); + + dev_info(dev, "tin at %lu, tdiv at %lu, tin=%sclk, base %d\n", + clk_get_rate(pwm->clk), + clk_get_rate(pwm->clk_div), + pwm_is_tdiv(pwm) ? "div" : "ext", pwm->tcon_base); + + platform_set_drvdata(pdev, pwm); + return 0; + + err_clk_tdiv: + clk_put(pwm->clk_div); + + err_clk_tin: + clk_put(pwm->clk); + + err_alloc: + kfree(pwm); + return ret; +} + +static int s3c_pwm_remove(struct platform_device *pdev) +{ + struct pwm_device *pwm = platform_get_drvdata(pdev); + + clk_put(pwm->clk_div); + clk_put(pwm->clk); + kfree(pwm); + + return 0; +} + +static struct platform_driver s3c_pwm_driver = { + .driver = { + .name = "s3c24xx-pwm", + .owner = THIS_MODULE, + }, + .probe = s3c_pwm_probe, + .remove = __devexit_p(s3c_pwm_remove), +}; + +static int __init pwm_init(void) +{ + int ret; + + clk_scaler[0] = clk_get(NULL, "pwm-scaler0"); + clk_scaler[1] = clk_get(NULL, "pwm-scaler1"); + + if (IS_ERR(clk_scaler[0]) || IS_ERR(clk_scaler[1])) { + printk(KERN_ERR "%s: failed to get scaler clocks\n", __func__); + return -EINVAL; + } + + ret = platform_driver_register(&s3c_pwm_driver); + if (ret) + printk(KERN_ERR "%s: failed to add pwm driver\n", __func__); + + return ret; +} + +arch_initcall(pwm_init); |