[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>

1 files changed, 56 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c24xx/clock.c b/arch/arm/plat-s3c24xx/clock.c
index 99a44746f8f2..d84167fb33b1 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 = {