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authorSekhar Nori <nsekhar@ti.com>2009-08-31 12:18:02 +0200
committerKevin Hilman <khilman@deeprootsystems.com>2009-11-25 19:21:20 +0100
commitde381a91f544008f4f99571e2ef1f60b92d5f0cf (patch)
treef15d31d2a7de9379e3fac9300eb2a2a190eab4a4 /arch/arm/mach-davinci
parentdavinci: enable easy top down traversal of clock tree (diff)
downloadlinux-de381a91f544008f4f99571e2ef1f60b92d5f0cf.tar.xz
linux-de381a91f544008f4f99571e2ef1f60b92d5f0cf.zip
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>
Diffstat (limited to 'arch/arm/mach-davinci')
-rw-r--r--arch/arm/mach-davinci/clock.c69
-rw-r--r--arch/arm/mach-davinci/clock.h1
2 files changed, 50 insertions, 20 deletions
diff --git a/arch/arm/mach-davinci/clock.c b/arch/arm/mach-davinci/clock.c
index f8c4ef08fbc2..6de1e3428f1f 100644
--- a/arch/arm/mach-davinci/clock.c
+++ b/arch/arm/mach-davinci/clock.c
@@ -135,8 +135,12 @@ int clk_register(struct clk *clk)
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 @@ static int __init clk_disable_unused(void)
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 unsigned long clk_leafclk_recalc(struct clk *clk)
+{
+ if (WARN_ON(!clk->parent))
+ return clk->rate;
+
+ return clk->parent->rate;
}
-static void __init clk_pll_init(struct clk *clk)
+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 @@ static void __init clk_pll_init(struct clk *clk)
}
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 @@ static void __init clk_pll_init(struct clk *clk)
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 @@ int __init davinci_clk_init(struct davinci_clk *clocks)
for (c = clocks; c->lk.clk; c++) {
clk = c->lk.clk;
- if (clk->pll_data)
- clk_pll_init(clk);
+ if (!clk->recalc) {
+
+ /* 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;
+ }
- /* Calculate rates for PLL-derived clocks */
- else if (clk->flags & CLK_PLL)
- clk_sysclk_recalc(clk);
+ if (clk->recalc)
+ clk->rate = clk->recalc(clk);
if (clk->lpsc)
clk->flags |= CLK_PSC;
diff --git a/arch/arm/mach-davinci/clock.h b/arch/arm/mach-davinci/clock.h
index f88794d7446e..202b9ff27b9d 100644
--- a/arch/arm/mach-davinci/clock.h
+++ b/arch/arm/mach-davinci/clock.h
@@ -73,6 +73,7 @@ struct clk {
struct list_head childnode; /* parent's child list node */
struct pll_data *pll_data;
u32 div_reg;
+ unsigned long (*recalc) (struct clk *);
};
/* Clock flags */