davinci: support changing the clock rate in clock framework

clk_round_rate, clk_set_rate have been updated to handle dynamic
frequency changes.

The motivation behind the changes is to support dynamic CPU frequency
change.

davinci_set_pllrate() changes the PLL rate of a given PLL. This function
has been presented as a generic function though it has been tested only
on OMAP-L138 EVM. No other currently available DaVinci device will probably
use this function, but any future device specific changes will hopefully be
small enough to get taken care using a cpu_is_xxx() macro.

Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/arch/arm/mach-davinci/clock.h b/arch/arm/mach-davinci/clock.h
index 202b9ff27b9d..a75d3f70b351 100644
--- a/arch/arm/mach-davinci/clock.h
+++ b/arch/arm/mach-davinci/clock.h
@@ -22,6 +22,10 @@
 /* PLL/Reset register offsets */
 #define PLLCTL          0x100
 #define PLLCTL_PLLEN    BIT(0)
+#define PLLCTL_PLLPWRDN BIT(1)
+#define PLLCTL_PLLRST   BIT(3)
+#define PLLCTL_PLLDIS   BIT(4)
+#define PLLCTL_PLLENSRC BIT(5)
 #define PLLCTL_CLKMODE  BIT(8)
 
 #define PLLM            0x110
@@ -74,6 +78,8 @@ struct clk {
         struct pll_data         *pll_data;
         u32                     div_reg;
         unsigned long (*recalc) (struct clk *);
+        int (*set_rate) (struct clk *clk, unsigned long rate);
+        int (*round_rate) (struct clk *clk, unsigned long rate);
 };
 
 /* Clock flags */
@@ -97,6 +103,8 @@ struct davinci_clk {
         }
 
 int davinci_clk_init(struct davinci_clk *clocks);
+int davinci_set_pllrate(struct pll_data *pll, unsigned int prediv,
+                                unsigned int mult, unsigned int postdiv);
 
 extern struct platform_device davinci_wdt_device;