Add s3c pwm device driver.

5 files changed, 776 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c/Kconfig b/arch/arm/plat-s3c/Kconfig
index 935c7558469..bae4b955edf 100644
--- a/arch/arm/plat-s3c/Kconfig
+++ b/arch/arm/plat-s3c/Kconfig
@@ -166,6 +166,11 @@ config S3C_DMA
 	help
 	  Internal configuration for S3C DMA core
 
+config S3C_PWM
+	bool
+	help
+	  PWM timer code for the S3C2410, and similar processors
+
 # device definitions to compile in
 
 config S3C_DEV_HSMMC
diff --git a/arch/arm/plat-s3c/Makefile b/arch/arm/plat-s3c/Makefile
index 0761766b183..4d8e4a35d34 100644
--- a/arch/arm/plat-s3c/Makefile
+++ b/arch/arm/plat-s3c/Makefile
@@ -38,3 +38,4 @@ obj-$(CONFIG_SND_S3C64XX_SOC_I2S)	+= dev-audio.o
 obj-$(CONFIG_S3C_DEV_FB)	+= dev-fb.o
 obj-$(CONFIG_S3C_DEV_USB_HOST)	+= dev-usb.o
 obj-$(CONFIG_S3C_DEV_USB_HSOTG)	+= dev-usb-hsotg.o
+obj-$(CONFIG_S3C_PWM)		+= pwm.o
diff --git a/arch/arm/plat-s3c/include/plat/pwm.h b/arch/arm/plat-s3c/include/plat/pwm.h
new file mode 100644
index 00000000000..6a41b0ad840
--- /dev/null
+++ b/arch/arm/plat-s3c/include/plat/pwm.h
@@ -0,0 +1,45 @@
+#ifndef __S3C2410_PWM_H
+#define __S3C2410_PWM_H
+
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+
+#include <mach/io.h>
+#include <mach/hardware.h>
+#include <asm/mach-types.h>
+#include <plat/regs-timer.h>
+
+enum pwm_timer {
+	PWM0,
+	PWM1,
+	PWM2,
+	PWM3,
+	PWM4
+};
+
+struct s3c2410_pwm {
+	enum pwm_timer timerid;
+	struct clk *pclk;
+	unsigned long pclk_rate;
+	unsigned long prescaler;
+	unsigned long divider;
+	unsigned long counter;
+	unsigned long comparer;
+};
+
+struct s3c24xx_pwm_platform_data{
+        /* callback to attach platform children (to enforce suspend / resume
+         * ordering */
+        void (*attach_child_devices)(struct device *parent_device);
+};
+
+int s3c2410_pwm_init(struct s3c2410_pwm *s3c2410_pwm);
+int s3c2410_pwm_enable(struct s3c2410_pwm *s3c2410_pwm);
+int s3c2410_pwm_disable(struct s3c2410_pwm *s3c2410_pwm);
+int s3c2410_pwm_start(struct s3c2410_pwm *s3c2410_pwm);
+int s3c2410_pwm_stop(struct s3c2410_pwm *s3c2410_pwm);
+int s3c2410_pwm_duty_cycle(int reg_value, struct s3c2410_pwm *s3c2410_pwm);
+int s3c2410_pwm_dumpregs(void);
+
+#endif /* __S3C2410_PWM_H */
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);
diff --git a/arch/arm/plat-s3c24xx/pwm-clock.c b/arch/arm/plat-s3c24xx/pwm-clock.c
new file mode 100644
index 00000000000..d41cccd6a25
--- /dev/null
+++ b/arch/arm/plat-s3c24xx/pwm-clock.c
@@ -0,0 +1,437 @@
+/* linux/arch/arm/plat-s3c24xx/pwm-clock.c
+ *
+ * Copyright (c) 2007 Simtec Electronics
+ * Copyright (c) 2007, 2008 Ben Dooks
+ *	Ben Dooks <ben-linux@fluff.org>
+ *
+ * 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/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/errno.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#include <mach/hardware.h>
+#include <asm/irq.h>
+
+#include <mach/regs-clock.h>
+#include <mach/regs-gpio.h>
+
+#include <asm/plat-s3c24xx/clock.h>
+#include <asm/plat-s3c24xx/cpu.h>
+
+#include <asm/plat-s3c/regs-timer.h>
+
+/* Each of the timers 0 through 5 go through the following
+ * clock tree, with the inputs depending on the timers.
+ *
+ * pclk ---- [ prescaler 0 ] -+---> timer 0
+ *			      +---> timer 1
+ *
+ * pclk ---- [ prescaler 1 ] -+---> timer 2
+ *			      +---> timer 3
+ *			      \---> timer 4
+ *
+ * Which are fed into the timers as so:
+ *
+ * prescaled 0 ---- [ div 2,4,8,16 ] ---\
+ *				       [mux] -> timer 0
+ * tclk 0 ------------------------------/
+ *
+ * prescaled 0 ---- [ div 2,4,8,16 ] ---\
+ *				       [mux] -> timer 1
+ * tclk 0 ------------------------------/
+ *
+ *
+ * prescaled 1 ---- [ div 2,4,8,16 ] ---\
+ *				       [mux] -> timer 2
+ * tclk 1 ------------------------------/
+ *
+ * prescaled 1 ---- [ div 2,4,8,16 ] ---\
+ *				       [mux] -> timer 3
+ * tclk 1 ------------------------------/
+ *
+ * prescaled 1 ---- [ div 2,4,8, 16 ] --\
+ *				       [mux] -> timer 4
+ * tclk 1 ------------------------------/
+ *
+ * Since the mux and the divider are tied together in the
+ * same register space, it is impossible to set the parent
+ * and the rate at the same time. To avoid this, we add an
+ * intermediate 'prescaled-and-divided' clock to select
+ * as the parent for the timer input clock called tdiv.
+ *
+ * prescaled clk --> pwm-tdiv ---\
+ *                             [ mux ] --> timer X
+ * tclk -------------------------/
+*/
+
+static unsigned long clk_pwm_scaler_getrate(struct clk *clk)
+{
+	unsigned long tcfg0 = __raw_readl(S3C2410_TCFG0);
+
+	if (clk->id == 1) {
+		tcfg0 &= S3C2410_TCFG_PRESCALER1_MASK;
+		tcfg0 >>= S3C2410_TCFG_PRESCALER1_SHIFT;
+	} else {
+		tcfg0 &= S3C2410_TCFG_PRESCALER0_MASK;
+	}
+
+	return clk_get_rate(clk->parent) / (tcfg0 + 1);
+}
+
+/* TODO - add set rate calls. */
+
+static struct clk clk_timer_scaler[] = {
+	[0]	= {
+		.name		= "pwm-scaler0",
+		.id		= -1,
+		.get_rate	= clk_pwm_scaler_getrate,
+	},
+	[1]	= {
+		.name		= "pwm-scaler1",
+		.id		= -1,
+		.get_rate	= clk_pwm_scaler_getrate,
+	},
+};
+
+static struct clk clk_timer_tclk[] = {
+	[0]	= {
+		.name		= "pwm-tclk0",
+		.id		= -1,
+	},
+	[1]	= {
+		.name		= "pwm-tclk1",
+		.id		= -1,
+	},
+};
+
+struct pwm_tdiv_clk {
+	struct clk	clk;
+	unsigned int	divisor;
+};
+
+static inline struct pwm_tdiv_clk *to_tdiv(struct clk *clk)
+{
+	return container_of(clk, struct pwm_tdiv_clk, clk);
+}
+
+static inline unsigned long tcfg_to_divisor(unsigned long tcfg1)
+{
+	return 1 << (1 + tcfg1);
+}
+
+static unsigned long clk_pwm_tdiv_get_rate(struct clk *clk)
+{
+	unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+	unsigned int divisor;
+
+	tcfg1 >>= S3C2410_TCFG1_SHIFT(clk->id);
+	tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+	if (tcfg1 == S3C2410_TCFG1_MUX_TCLK)
+		divisor = to_tdiv(clk)->divisor;
+	else
+		divisor = tcfg_to_divisor(tcfg1);
+
+	return clk_get_rate(clk->parent) / divisor;
+}
+
+static unsigned long clk_pwm_tdiv_round_rate(struct clk *clk,
+					     unsigned long rate)
+{
+	unsigned long parent_rate;
+	unsigned long divisor;
+
+	parent_rate = clk_get_rate(clk->parent);
+	divisor = parent_rate / rate;
+
+	if (divisor <= 2)
+		divisor = 2;
+	else if (divisor <= 4)
+		divisor = 4;
+	else if (divisor <= 8)
+		divisor = 8;
+	else
+		divisor = 16;
+
+	return parent_rate / divisor;
+}
+
+static unsigned long clk_pwm_tdiv_bits(struct pwm_tdiv_clk *divclk)
+{
+	unsigned long bits;
+
+	switch (divclk->divisor) {
+	case 2:
+		bits = S3C2410_TCFG1_MUX_DIV2;
+		break;
+	case 4:
+		bits = S3C2410_TCFG1_MUX_DIV4;
+		break;
+	case 8:
+		bits = S3C2410_TCFG1_MUX_DIV8;
+		break;
+	case 16:
+	default:
+		bits = S3C2410_TCFG1_MUX_DIV16;
+		break;
+	}
+
+	return bits;
+}
+
+static void clk_pwm_tdiv_update(struct pwm_tdiv_clk *divclk)
+{
+	unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+	unsigned long bits = clk_pwm_tdiv_bits(divclk);
+	unsigned long flags;
+	unsigned long shift =  S3C2410_TCFG1_SHIFT(divclk->clk.id);
+
+	local_irq_save(flags);
+
+	tcfg1 = __raw_readl(S3C2410_TCFG1);
+	tcfg1 &= ~(S3C2410_TCFG1_MUX_MASK << shift);
+	tcfg1 |= bits << shift;
+	__raw_writel(tcfg1, S3C2410_TCFG1);
+
+	local_irq_restore(flags);
+}
+
+static int clk_pwm_tdiv_set_rate(struct clk *clk, unsigned long rate)
+{
+	struct pwm_tdiv_clk *divclk = to_tdiv(clk);
+	unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+	unsigned long parent_rate = clk_get_rate(clk->parent);
+	unsigned long divisor;
+
+	tcfg1 >>= S3C2410_TCFG1_SHIFT(clk->id);
+	tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+	rate = clk_round_rate(clk, rate);
+	divisor = parent_rate / rate;
+
+	if (divisor > 16)
+		return -EINVAL;
+
+	divclk->divisor = divisor;
+
+	/* Update the current MUX settings if we are currently
+	 * selected as the clock source for this clock. */
+
+	if (tcfg1 != S3C2410_TCFG1_MUX_TCLK)
+		clk_pwm_tdiv_update(divclk);
+
+	return 0;
+}
+
+static struct pwm_tdiv_clk clk_timer_tdiv[] = {
+	[0]	= {
+		.clk	= {
+			.name		= "pwm-tdiv",
+			.parent		= &clk_timer_scaler[0],
+			.get_rate	= clk_pwm_tdiv_get_rate,
+			.set_rate	= clk_pwm_tdiv_set_rate,
+			.round_rate	= clk_pwm_tdiv_round_rate,
+		},
+	},
+	[1]	= {
+		.clk	= {
+			.name		= "pwm-tdiv",
+			.parent		= &clk_timer_scaler[0],
+			.get_rate	= clk_pwm_tdiv_get_rate,
+			.set_rate	= clk_pwm_tdiv_set_rate,
+			.round_rate	= clk_pwm_tdiv_round_rate,
+		}
+	},
+	[2]	= {
+		.clk	= {
+			.name		= "pwm-tdiv",
+			.parent		= &clk_timer_scaler[1],
+			.get_rate	= clk_pwm_tdiv_get_rate,
+			.set_rate	= clk_pwm_tdiv_set_rate,
+			.round_rate	= clk_pwm_tdiv_round_rate,
+		},
+	},
+	[3]	= {
+		.clk	= {
+			.name		= "pwm-tdiv",
+			.parent		= &clk_timer_scaler[1],
+			.get_rate	= clk_pwm_tdiv_get_rate,
+			.set_rate	= clk_pwm_tdiv_set_rate,
+			.round_rate	= clk_pwm_tdiv_round_rate,
+		},
+	},
+	[4]	= {
+		.clk	= {
+			.name		= "pwm-tdiv",
+			.parent		= &clk_timer_scaler[1],
+			.get_rate	= clk_pwm_tdiv_get_rate,
+			.set_rate	= clk_pwm_tdiv_set_rate,
+			.round_rate	= clk_pwm_tdiv_round_rate,
+		},
+	},
+};
+
+static int __init clk_pwm_tdiv_register(unsigned int id)
+{
+	struct pwm_tdiv_clk *divclk = &clk_timer_tdiv[id];
+	unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+
+	tcfg1 >>= S3C2410_TCFG1_SHIFT(id);
+	tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+	divclk->clk.id = id;
+	divclk->divisor = tcfg_to_divisor(tcfg1);
+
+	return s3c24xx_register_clock(&divclk->clk);
+}
+
+static inline struct clk *s3c24xx_pwmclk_tclk(unsigned int id)
+{
+	return (id >= 2) ? &clk_timer_tclk[1] : &clk_timer_tclk[0];
+}
+
+static inline struct clk *s3c24xx_pwmclk_tdiv(unsigned int id)
+{
+	return &clk_timer_tdiv[id].clk;
+}
+
+static int clk_pwm_tin_set_parent(struct clk *clk, struct clk *parent)
+{
+	unsigned int id = clk->id;
+	unsigned long tcfg1;
+	unsigned long flags;
+	unsigned long bits;
+	unsigned long shift = S3C2410_TCFG1_SHIFT(id);
+
+	if (parent == s3c24xx_pwmclk_tclk(id))
+		bits = S3C2410_TCFG1_MUX_TCLK << shift;
+	else if (parent == s3c24xx_pwmclk_tdiv(id))
+		bits = clk_pwm_tdiv_bits(to_tdiv(parent)) << shift;
+	else
+		return -EINVAL;
+
+	clk->parent = parent;
+
+	local_irq_save(flags);
+
+	tcfg1 = __raw_readl(S3C2410_TCFG1);
+	tcfg1 &= ~(S3C2410_TCFG1_MUX_MASK << shift);
+	__raw_writel(tcfg1 | bits, S3C2410_TCFG1);
+
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static struct clk clk_tin[] = {
+	[0]	= {
+		.name		= "pwm-tin",
+		.id		= 0,
+		.set_parent	= clk_pwm_tin_set_parent,
+	},
+	[1]	= {
+		.name		= "pwm-tin",
+		.id		= 1,
+		.set_parent	= clk_pwm_tin_set_parent,
+	},
+	[2]	= {
+		.name		= "pwm-tin",
+		.id		= 2,
+		.set_parent	= clk_pwm_tin_set_parent,
+	},
+	[3]	= {
+		.name		= "pwm-tin",
+		.id		= 3,
+		.set_parent	= clk_pwm_tin_set_parent,
+	},
+	[4]	= {
+		.name		= "pwm-tin",
+		.id		= 4,
+		.set_parent	= clk_pwm_tin_set_parent,
+	},
+};
+
+static __init int clk_pwm_tin_register(struct clk *pwm)
+{
+	unsigned long tcfg1 = __raw_readl(S3C2410_TCFG1);
+	unsigned int id = pwm->id;
+
+	struct clk *parent;
+	int ret;
+
+	ret = s3c24xx_register_clock(pwm);
+	if (ret < 0)
+		return ret;
+
+	tcfg1 >>= S3C2410_TCFG1_SHIFT(id);
+	tcfg1 &= S3C2410_TCFG1_MUX_MASK;
+
+	if (tcfg1 == S3C2410_TCFG1_MUX_TCLK)
+		parent = s3c24xx_pwmclk_tclk(id);
+	else
+		parent = s3c24xx_pwmclk_tdiv(id);
+
+	return clk_set_parent(pwm, parent);
+}
+
+static __init int s3c24xx_pwmclk_init(void)
+{
+	struct clk *clk_timers;
+	unsigned int clk;
+	int ret;
+
+	clk_timers = clk_get(NULL, "timers");
+	if (IS_ERR(clk_timers)) {
+		printk(KERN_ERR "%s: no parent clock\n", __func__);
+		return -EINVAL;
+	}
+
+	for (clk = 0; clk < ARRAY_SIZE(clk_timer_scaler); clk++) {
+		clk_timer_scaler[clk].parent = clk_timers;
+		ret = s3c24xx_register_clock(&clk_timer_scaler[clk]);
+		if (ret < 0) {
+			printk(KERN_ERR "error adding pwm scaler%d clock\n", clk);
+			goto err;
+		}
+	}
+
+	for (clk = 0; clk < ARRAY_SIZE(clk_timer_tclk); clk++) {
+		ret = s3c24xx_register_clock(&clk_timer_tclk[clk]);
+		if (ret < 0) {
+			printk(KERN_ERR "error adding pww tclk%d\n", clk);
+			goto err;
+		}
+	}
+
+	for (clk = 0; clk < ARRAY_SIZE(clk_timer_tdiv); clk++) {
+		ret = clk_pwm_tdiv_register(clk);
+		if (ret < 0) {
+			printk(KERN_ERR "error adding pwm%d tdiv clock\n", clk);
+			goto err;
+		}
+	}
+
+	for (clk = 0; clk < ARRAY_SIZE(clk_tin); clk++) {
+		ret = clk_pwm_tin_register(&clk_tin[clk]);
+		if (ret < 0) {
+			printk(KERN_ERR "error adding pwm%d tin clock\n", clk);
+			goto err;
+		}
+	}
+
+	return 0;
+
+ err:
+	return ret;
+}
+
+arch_initcall(s3c24xx_pwmclk_init);