davinci: make clock rate re-calculation easy
Make clock rate recalculation easy by having a re-calculate
function for each clock.
The existing functions for calculation of output rates of PLL
and PLL-derived sysclks have been convered to the new
re-calculate API.
A new function is introduced to take care of rate
(re)calculation for leaf clocks.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
index f8c4ef08..6de1e34 100644
--- a/arch/arm/mach-davinci/clock.c
+++ b/arch/arm/mach-davinci/clock.c
@@ -135,8 +135,12 @@
if (clk->rate)
return 0;
+ /* Else, see if there is a way to calculate it */
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
+
/* Otherwise, default to parent rate */
- if (clk->parent)
+ else if (clk->parent)
clk->rate = clk->parent->rate;
return 0;
@@ -184,50 +188,62 @@
late_initcall(clk_disable_unused);
#endif
-static void clk_sysclk_recalc(struct clk *clk)
+static unsigned long clk_sysclk_recalc(struct clk *clk)
{
u32 v, plldiv;
struct pll_data *pll;
+ unsigned long rate = clk->rate;
/* If this is the PLL base clock, no more calculations needed */
if (clk->pll_data)
- return;
+ return rate;
if (WARN_ON(!clk->parent))
- return;
+ return rate;
- clk->rate = clk->parent->rate;
+ rate = clk->parent->rate;
/* Otherwise, the parent must be a PLL */
if (WARN_ON(!clk->parent->pll_data))
- return;
+ return rate;
pll = clk->parent->pll_data;
/* If pre-PLL, source clock is before the multiplier and divider(s) */
if (clk->flags & PRE_PLL)
- clk->rate = pll->input_rate;
+ rate = pll->input_rate;
if (!clk->div_reg)
- return;
+ return rate;
v = __raw_readl(pll->base + clk->div_reg);
if (v & PLLDIV_EN) {
plldiv = (v & PLLDIV_RATIO_MASK) + 1;
if (plldiv)
- clk->rate /= plldiv;
+ rate /= plldiv;
}
+
+ return rate;
}
-static void __init clk_pll_init(struct clk *clk)
+static unsigned long clk_leafclk_recalc(struct clk *clk)
+{
+ if (WARN_ON(!clk->parent))
+ return clk->rate;
+
+ return clk->parent->rate;
+}
+
+static unsigned long clk_pllclk_recalc(struct clk *clk)
{
u32 ctrl, mult = 1, prediv = 1, postdiv = 1;
u8 bypass;
struct pll_data *pll = clk->pll_data;
+ unsigned long rate = clk->rate;
pll->base = IO_ADDRESS(pll->phys_base);
ctrl = __raw_readl(pll->base + PLLCTL);
- clk->rate = pll->input_rate = clk->parent->rate;
+ rate = pll->input_rate = clk->parent->rate;
if (ctrl & PLLCTL_PLLEN) {
bypass = 0;
@@ -260,9 +276,9 @@
}
if (!bypass) {
- clk->rate /= prediv;
- clk->rate *= mult;
- clk->rate /= postdiv;
+ rate /= prediv;
+ rate *= mult;
+ rate /= postdiv;
}
pr_debug("PLL%d: input = %lu MHz [ ",
@@ -275,7 +291,9 @@
pr_debug("* %d ", mult);
if (postdiv > 1)
pr_debug("/ %d ", postdiv);
- pr_debug("] --> %lu MHz output.\n", clk->rate / 1000000);
+ pr_debug("] --> %lu MHz output.\n", rate / 1000000);
+
+ return rate;
}
int __init davinci_clk_init(struct davinci_clk *clocks)
@@ -286,12 +304,23 @@
for (c = clocks; c->lk.clk; c++) {
clk = c->lk.clk;
- if (clk->pll_data)
- clk_pll_init(clk);
+ if (!clk->recalc) {
- /* Calculate rates for PLL-derived clocks */
- else if (clk->flags & CLK_PLL)
- clk_sysclk_recalc(clk);
+ /* Check if clock is a PLL */
+ if (clk->pll_data)
+ clk->recalc = clk_pllclk_recalc;
+
+ /* Else, if it is a PLL-derived clock */
+ else if (clk->flags & CLK_PLL)
+ clk->recalc = clk_sysclk_recalc;
+
+ /* Otherwise, it is a leaf clock (PSC clock) */
+ else if (clk->parent)
+ clk->recalc = clk_leafclk_recalc;
+ }
+
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
if (clk->lpsc)
clk->flags |= CLK_PSC;