From: Paul Walmsley <paul@xxxxxxxxx>
Add the omap3_core_dpll_m2_set_rate() function to the OMAP3 clock code,
which calls into the SRAM function omap3_sram_configure_core_dpll() to
change the CORE DPLL M2 divider. (SRAM code is necessary since rate changes
on clocks upstream from the SDRC can glitch SDRAM accesses.)
Use this function for the set_rate function pointer in the dpll3_m2_ck
struct clk. With this function in place, PM/OPP code should be able to
alter SDRAM speed via code similar to:
clk_set_rate(&dpll3_m2_ck, target_rate).
linux-omap source commit is 7f8b2b0f4fe52238c67d79dedcd2794dcef4dddd.
Signed-off-by: Paul Walmsley <paul@xxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
---
arch/arm/mach-omap2/clock34xx.c | 65 +++++++++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/clock34xx.h | 9 ++---
2 files changed, 69 insertions(+), 5 deletions(-)
diff --git a/arch/arm/mach-omap2/clock34xx.c b/arch/arm/mach-omap2/clock34xx.c
index 52385b1..1ad0a13 100644
--- a/arch/arm/mach-omap2/clock34xx.c
+++ b/arch/arm/mach-omap2/clock34xx.c
@@ -634,6 +634,71 @@ static int omap3_dpll4_set_rate(struct clk *clk, unsigned long rate)
return omap3_noncore_dpll_set_rate(clk, rate);
}
+
+/*
+ * CORE DPLL (DPLL3) rate programming functions
+ *
+ * These call into SRAM code to do the actual CM writes, since the SDRAM
+ * is clocked from DPLL3.
+ */
+
+/**
+ * omap3_core_dpll_m2_set_rate - set CORE DPLL M2 divider
+ * @clk: struct clk * of DPLL to set
+ * @rate: rounded target rate
+ *
+ * Program the DPLL M2 divider with the rounded target rate. Returns
+ * -EINVAL upon error, or 0 upon success.
+ */
+static int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate)
+{
+ u32 new_div = 0;
+ unsigned long validrate, sdrcrate;
+ struct omap_sdrc_params *sp;
+
+ if (!clk || !rate)
+ return -EINVAL;
+
+ if (clk != &dpll3_m2_ck)
+ return -EINVAL;
+
+ if (rate == clk->rate)
+ return 0;
+
+ validrate = omap2_clksel_round_rate_div(clk, rate, &new_div);
+ if (validrate != rate)
+ return -EINVAL;
+
+ sdrcrate = sdrc_ick.rate;
+ if (rate > clk->rate)
+ sdrcrate <<= ((rate / clk->rate) - 1);
+ else
+ sdrcrate >>= ((clk->rate / rate) - 1);
+
+ sp = omap2_sdrc_get_params(sdrcrate);
+ if (!sp)
+ return -EINVAL;
+
+ pr_info("clock: changing CORE DPLL rate from %lu to %lu\n", clk->rate,
+ validrate);
+ pr_info("clock: SDRC timing params used: %08x %08x %08x\n",
+ sp->rfr_ctrl, sp->actim_ctrla, sp->actim_ctrlb);
+
+ /* REVISIT: SRAM code doesn't support other M2 divisors yet */
+ WARN_ON(new_div != 1 && new_div != 2);
+
+ /* REVISIT: Add SDRC_MR changing to this code also */
+ local_irq_disable();
+ omap3_configure_core_dpll(sp->rfr_ctrl, sp->actim_ctrla,
+ sp->actim_ctrlb, new_div);
+ local_irq_enable();
+
+ omap2_clksel_recalc(clk);
+
+ return 0;
+}
+
+
static const struct clkops clkops_noncore_dpll_ops = {
.enable = &omap3_noncore_dpll_enable,
.disable = &omap3_noncore_dpll_disable,
diff --git a/arch/arm/mach-omap2/clock34xx.h b/arch/arm/mach-omap2/clock34xx.h
index aadd296..681acf0 100644
--- a/arch/arm/mach-omap2/clock34xx.h
+++ b/arch/arm/mach-omap2/clock34xx.h
@@ -34,6 +34,7 @@ static void omap3_dpll_deny_idle(struct clk *clk);
static u32 omap3_dpll_autoidle_read(struct clk *clk);
static int omap3_noncore_dpll_set_rate(struct clk *clk, unsigned long rate);
static int omap3_dpll4_set_rate(struct clk *clk, unsigned long rate);
+static int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate);
/* Maximum DPLL multiplier, divider values for OMAP3 */
#define OMAP3_MAX_DPLL_MULT 2048
@@ -471,11 +472,7 @@ static const struct clksel div31_dpll3m2_clksel[] = {
{ .parent = NULL }
};
-/*
- * DPLL3 output M2
- * REVISIT: This DPLL output divider must be changed in SRAM, so until
- * that code is ready, this should remain a 'read-only' clksel clock.
- */
+/* DPLL3 output M2 - primary control point for CORE speed */
static struct clk dpll3_m2_ck = {
.name = "dpll3_m2_ck",
.ops = &clkops_null,
@@ -486,6 +483,8 @@ static struct clk dpll3_m2_ck = {
.clksel = div31_dpll3m2_clksel,
.flags = RATE_PROPAGATES,
.clkdm_name = "dpll3_clkdm",
+ .round_rate = &omap2_clksel_round_rate,
+ .set_rate = &omap3_core_dpll_m2_set_rate,
.recalc = &omap2_clksel_recalc,
};
--
1.6.1.2
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