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authorDavide Rizzo <davide@elpa.it>2008-04-12 15:08:15 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2008-04-19 14:04:30 +0100
commiteb1f7d10d6b6728c87f79f30d1ae844d01d3486a (patch)
tree4a3dbdceea736fee36a869f554acd1e16039b6f5 /arch/arm/plat-s3c24xx
parent79b34afa68de4088081bcb7b4aed0fc4d8bf3618 (diff)
[ARM] 4967/1: Adds functions to set clkout rate for Samsung S3C2410
This patch adds functions to set clkout rate for Samsung S3C2410 This patch supersedes 4884/1, that contained an error Comments from Ben Dooks: Note, looks like this needs to be applied before 4882/1 Signed-off-by: Davide Rizzo <davide@elpa.it> Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/plat-s3c24xx')
-rw-r--r--arch/arm/plat-s3c24xx/clock.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/arm/plat-s3c24xx/clock.c b/arch/arm/plat-s3c24xx/clock.c
index 99a44746f8f..d84167fb33b 100644
--- a/arch/arm/plat-s3c24xx/clock.c
+++ b/arch/arm/plat-s3c24xx/clock.c
@@ -332,6 +332,58 @@ static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
return 0;
}
+static unsigned long s3c24xx_calc_div(struct clk *clk, unsigned long rate)
+{
+ unsigned long div;
+
+ if ((rate == 0) || !clk->parent)
+ return 0;
+
+ div = clk_get_rate(clk->parent) / rate;
+ if (div < 2)
+ div = 2;
+ else if (div > 16)
+ div = 16;
+
+ return div;
+}
+
+static unsigned long s3c24xx_round_dclk_rate(struct clk *clk,
+ unsigned long rate)
+{
+ unsigned long div = s3c24xx_calc_div(clk, rate);
+
+ if (div == 0)
+ return 0;
+
+ return clk_get_rate(clk->parent) / div;
+}
+
+static int s3c24xx_set_dclk_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned long mask, data, div = s3c24xx_calc_div(clk, rate);
+
+ if (div == 0)
+ return -EINVAL;
+
+ if (clk == &s3c24xx_dclk0) {
+ mask = S3C2410_DCLKCON_DCLK0_DIV_MASK |
+ S3C2410_DCLKCON_DCLK0_CMP_MASK;
+ data = S3C2410_DCLKCON_DCLK0_DIV(div) |
+ S3C2410_DCLKCON_DCLK0_CMP((div + 1) / 2);
+ } else if (clk == &s3c24xx_dclk1) {
+ mask = S3C2410_DCLKCON_DCLK1_DIV_MASK |
+ S3C2410_DCLKCON_DCLK1_CMP_MASK;
+ data = S3C2410_DCLKCON_DCLK1_DIV(div) |
+ S3C2410_DCLKCON_DCLK1_CMP((div + 1) / 2);
+ } else
+ return -EINVAL;
+
+ clk->rate = clk_get_rate(clk->parent) / div;
+ __raw_writel(((__raw_readl(S3C24XX_DCLKCON) & ~mask) | data),
+ S3C24XX_DCLKCON);
+ return clk->rate;
+}
static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
{
@@ -378,6 +430,8 @@ struct clk s3c24xx_dclk0 = {
.ctrlbit = S3C2410_DCLKCON_DCLK0EN,
.enable = s3c24xx_dclk_enable,
.set_parent = s3c24xx_dclk_setparent,
+ .set_rate = s3c24xx_set_dclk_rate,
+ .round_rate = s3c24xx_round_dclk_rate,
};
struct clk s3c24xx_dclk1 = {
@@ -386,6 +440,8 @@ struct clk s3c24xx_dclk1 = {
.ctrlbit = S3C2410_DCLKCON_DCLK0EN,
.enable = s3c24xx_dclk_enable,
.set_parent = s3c24xx_dclk_setparent,
+ .set_rate = s3c24xx_set_dclk_rate,
+ .round_rate = s3c24xx_round_dclk_rate,
};
struct clk s3c24xx_clkout0 = {