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Diffstat (limited to 'arch/arm/mach-ep93xx/clock.c')
-rw-r--r--arch/arm/mach-ep93xx/clock.c88
1 files changed, 87 insertions, 1 deletions
diff --git a/arch/arm/mach-ep93xx/clock.c b/arch/arm/mach-ep93xx/clock.c
index 3dd0e2a2309..dda19cd7619 100644
--- a/arch/arm/mach-ep93xx/clock.c
+++ b/arch/arm/mach-ep93xx/clock.c
@@ -37,7 +37,7 @@ struct clk {
static unsigned long get_uart_rate(struct clk *clk);
static int set_keytchclk_rate(struct clk *clk, unsigned long rate);
-
+static int set_div_rate(struct clk *clk, unsigned long rate);
static struct clk clk_uart1 = {
.sw_locked = 1,
@@ -76,6 +76,13 @@ static struct clk clk_pwm = {
.rate = EP93XX_EXT_CLK_RATE,
};
+static struct clk clk_video = {
+ .sw_locked = 1,
+ .enable_reg = EP93XX_SYSCON_VIDCLKDIV,
+ .enable_mask = EP93XX_SYSCON_CLKDIV_ENABLE,
+ .set_rate = set_div_rate,
+};
+
/* DMA Clocks */
static struct clk clk_m2p0 = {
.enable_reg = EP93XX_SYSCON_PWRCNT,
@@ -140,6 +147,7 @@ static struct clk_lookup clocks[] = {
INIT_CK(NULL, "pll2", &clk_pll2),
INIT_CK("ep93xx-ohci", NULL, &clk_usb_host),
INIT_CK("ep93xx-keypad", NULL, &clk_keypad),
+ INIT_CK("ep93xx-fb", NULL, &clk_video),
INIT_CK(NULL, "pwm_clk", &clk_pwm),
INIT_CK(NULL, "m2p0", &clk_m2p0),
INIT_CK(NULL, "m2p1", &clk_m2p1),
@@ -236,6 +244,84 @@ static int set_keytchclk_rate(struct clk *clk, unsigned long rate)
return 0;
}
+static unsigned long calc_clk_div(unsigned long rate, int *psel, int *esel,
+ int *pdiv, int *div)
+{
+ unsigned long max_rate, best_rate = 0,
+ actual_rate = 0, mclk_rate = 0, rate_err = -1;
+ int i, found = 0, __div = 0, __pdiv = 0;
+
+ /* Don't exceed the maximum rate */
+ max_rate = max(max(clk_pll1.rate / 4, clk_pll2.rate / 4),
+ (unsigned long)EP93XX_EXT_CLK_RATE / 4);
+ rate = min(rate, max_rate);
+
+ /*
+ * Try the two pll's and the external clock
+ * Because the valid predividers are 2, 2.5 and 3, we multiply
+ * all the clocks by 2 to avoid floating point math.
+ *
+ * This is based on the algorithm in the ep93xx raster guide:
+ * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
+ *
+ */
+ for (i = 0; i < 3; i++) {
+ if (i == 0)
+ mclk_rate = EP93XX_EXT_CLK_RATE * 2;
+ else if (i == 1)
+ mclk_rate = clk_pll1.rate * 2;
+ else if (i == 2)
+ mclk_rate = clk_pll2.rate * 2;
+
+ /* Try each predivider value */
+ for (__pdiv = 4; __pdiv <= 6; __pdiv++) {
+ __div = mclk_rate / (rate * __pdiv);
+ if (__div < 2 || __div > 127)
+ continue;
+
+ actual_rate = mclk_rate / (__pdiv * __div);
+
+ if (!found || abs(actual_rate - rate) < rate_err) {
+ *pdiv = __pdiv - 3;
+ *div = __div;
+ *psel = (i == 2);
+ *esel = (i != 0);
+ best_rate = actual_rate;
+ rate_err = abs(actual_rate - rate);
+ found = 1;
+ }
+ }
+ }
+
+ if (!found)
+ return 0;
+
+ return best_rate;
+}
+
+static int set_div_rate(struct clk *clk, unsigned long rate)
+{
+ unsigned long actual_rate;
+ int psel = 0, esel = 0, pdiv = 0, div = 0;
+ u32 val;
+
+ actual_rate = calc_clk_div(rate, &psel, &esel, &pdiv, &div);
+ if (actual_rate == 0)
+ return -EINVAL;
+ clk->rate = actual_rate;
+
+ /* Clear the esel, psel, pdiv and div bits */
+ val = __raw_readl(clk->enable_reg);
+ val &= ~0x7fff;
+
+ /* Set the new esel, psel, pdiv and div bits for the new clock rate */
+ val |= (esel ? EP93XX_SYSCON_CLKDIV_ESEL : 0) |
+ (psel ? EP93XX_SYSCON_CLKDIV_PSEL : 0) |
+ (pdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | div;
+ ep93xx_syscon_swlocked_write(val, clk->enable_reg);
+ return 0;
+}
+
int clk_set_rate(struct clk *clk, unsigned long rate)
{
if (clk->set_rate)