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authorBen Dooks <ben-linux@fluff.org>2008-11-21 11:36:04 +0100
committerBen Dooks <ben-linux@fluff.org>2008-12-15 22:46:24 +0100
commit82fd8e681d60a195ce6e9fc783d0ebe7a81b1ead (patch)
tree8163599c280ebacf42015f3b3bf0a159e330d180 /arch/arm/plat-s3c
parent[ARM] S3C24XX: Reduce code lineage of gpiolib.c (diff)
downloadlinux-82fd8e681d60a195ce6e9fc783d0ebe7a81b1ead.tar.xz
linux-82fd8e681d60a195ce6e9fc783d0ebe7a81b1ead.zip
[ARM] S3C: Add set_rate/round_rate methods for pwm-scaler clock
Add the set_rate and round_rate methods for the pwm-scaler clock for use with the time code. Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Diffstat (limited to 'arch/arm/plat-s3c')
-rw-r--r--arch/arm/plat-s3c/pwm-clock.c51
1 files changed, 47 insertions, 4 deletions
diff --git a/arch/arm/plat-s3c/pwm-clock.c b/arch/arm/plat-s3c/pwm-clock.c
index 3fad68a1e6bc..b0fcbc1fb64b 100644
--- a/arch/arm/plat-s3c/pwm-clock.c
+++ b/arch/arm/plat-s3c/pwm-clock.c
@@ -73,7 +73,7 @@
* tclk -------------------------/
*/
-static unsigned long clk_pwm_scaler_getrate(struct clk *clk)
+static unsigned long clk_pwm_scaler_get_rate(struct clk *clk)
{
unsigned long tcfg0 = __raw_readl(S3C2410_TCFG0);
@@ -87,18 +87,61 @@ static unsigned long clk_pwm_scaler_getrate(struct clk *clk)
return clk_get_rate(clk->parent) / (tcfg0 + 1);
}
-/* TODO - add set rate calls. */
+static unsigned long clk_pwm_scaler_round_rate(struct clk *clk,
+ unsigned long rate)
+{
+ unsigned long parent_rate = clk_get_rate(clk->parent);
+ unsigned long divisor = parent_rate / rate;
+
+ if (divisor > 256)
+ divisor = 256;
+ else if (divisor < 2)
+ divisor = 2;
+
+ return parent_rate / divisor;
+}
+
+static int clk_pwm_scaler_set_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned long round = clk_pwm_scaler_round_rate(clk, rate);
+ unsigned long tcfg0;
+ unsigned long divisor;
+ unsigned long flags;
+
+ divisor = clk_get_rate(clk->parent) / round;
+ divisor--;
+
+ local_irq_save(flags);
+ tcfg0 = __raw_readl(S3C2410_TCFG0);
+
+ if (clk->id == 1) {
+ tcfg0 &= ~S3C2410_TCFG_PRESCALER1_MASK;
+ tcfg0 |= divisor << S3C2410_TCFG_PRESCALER1_SHIFT;
+ } else {
+ tcfg0 &= ~S3C2410_TCFG_PRESCALER0_MASK;
+ tcfg0 |= divisor;
+ }
+
+ __raw_writel(tcfg0, S3C2410_TCFG0);
+ local_irq_restore(flags);
+
+ return 0;
+}
static struct clk clk_timer_scaler[] = {
[0] = {
.name = "pwm-scaler0",
.id = -1,
- .get_rate = clk_pwm_scaler_getrate,
+ .get_rate = clk_pwm_scaler_get_rate,
+ .set_rate = clk_pwm_scaler_set_rate,
+ .round_rate = clk_pwm_scaler_round_rate,
},
[1] = {
.name = "pwm-scaler1",
.id = -1,
- .get_rate = clk_pwm_scaler_getrate,
+ .get_rate = clk_pwm_scaler_get_rate,
+ .set_rate = clk_pwm_scaler_set_rate,
+ .round_rate = clk_pwm_scaler_round_rate,
},
};