ARM: S3C2443: Add set_rate and round_rate calls for armdiv clock
authorBen Dooks <ben-linux@fluff.org>
Sat, 30 Jan 2010 09:14:14 +0000 (11:14 +0200)
committerBen Dooks <ben-linux@fluff.org>
Sun, 7 Mar 2010 22:56:13 +0000 (22:56 +0000)
Add set_rate and round_rate calls to armdiv for future use with cpu
frequency scaling.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
arch/arm/mach-s3c2443/clock.c

index 177719c..62cd4ea 100644 (file)
@@ -165,10 +165,83 @@ static struct clksrc_clk clk_msysclk = {
  * divider values applied to it to then be fed into armclk.
 */
 
+/* armdiv divisor table */
+
+static unsigned int armdiv[16] = {
+       [S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 1,
+       [S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 2,
+       [S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 3,
+       [S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 4,
+       [S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 6,
+       [S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 8,
+       [S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]     = 12,
+       [S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]     = 16,
+};
+
+static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0)
+{
+       clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;
+
+       return armdiv[clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT];
+}
+
+static unsigned long s3c2443_armclk_roundrate(struct clk *clk,
+                                             unsigned long rate)
+{
+       unsigned long parent = clk_get_rate(clk->parent);
+       unsigned long calc;
+       unsigned best = 256; /* bigger than any value */
+       unsigned div;
+       int ptr;
+
+       for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) {
+               div = armdiv[ptr];
+               calc = parent / div;
+               if (calc <= rate && div < best)
+                       best = div;
+       }
+
+       return parent / best;
+}
+
+static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate)
+{
+       unsigned long parent = clk_get_rate(clk->parent);
+       unsigned long calc;
+       unsigned div;
+       unsigned best = 256; /* bigger than any value */
+       int ptr;
+       int val = -1;
+
+       for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) {
+               div = armdiv[ptr];
+               calc = parent / div;
+               if (calc <= rate && div < best) {
+                       best = div;
+                       val = ptr;
+               }
+       }
+
+       if (val >= 0) {
+               unsigned long clkcon0;
+
+               clkcon0 = __raw_readl(S3C2443_CLKDIV0);
+               clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;
+               clkcon0 |= val << S3C2443_CLKDIV0_ARMDIV_SHIFT;
+               __raw_writel(clkcon0, S3C2443_CLKDIV0);
+       }
+
+       return (val == -1) ? -EINVAL : 0;
+}
+
 static struct clk clk_armdiv = {
        .name           = "armdiv",
        .id             = -1,
        .parent         = &clk_msysclk.clk,
+       .ops            = &(struct clk_ops) {
+               .round_rate = s3c2443_armclk_roundrate,
+               .set_rate = s3c2443_armclk_setrate,
+       },
 };
 
 /* armclk
@@ -619,26 +692,6 @@ static void __init s3c2443_clk_initparents(void)
                s3c_set_clksrc(init_list[ptr], true);
 }
 
-/* armdiv divisor table */
-
-static unsigned int armdiv[16] = {
-       [S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 1,
-       [S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 2,
-       [S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 3,
-       [S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 4,
-       [S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 6,
-       [S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]      = 8,
-       [S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]     = 12,
-       [S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT]     = 16,
-};
-
-static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0)
-{
-       clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;
-
-       return armdiv[clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT];
-}
-
 static inline unsigned long s3c2443_get_hdiv(unsigned long clkcon0)
 {
        clkcon0 &= S3C2443_CLKDIV0_HCLKDIV_MASK;