diff options
author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2009-06-20 10:57:40 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-06-20 10:57:40 +0100 |
commit | 312cec5d094a5d4e68434ace4c5cb55e4f8dfee5 (patch) | |
tree | d1471ecdc5005835a1861406d4a3395625381094 /arch/arm/mach-omap2/clock34xx.c | |
parent | 48ec2b53fe6a7244d62c74876ae00b0d7e03b4c5 (diff) | |
parent | 2687069f3ac297b820c58de7222e4d16adbca498 (diff) |
Merge branch 'omap-clock-for-next' of git://git.pwsan.com/linux-2.6 into devel
Diffstat (limited to 'arch/arm/mach-omap2/clock34xx.c')
-rw-r--r-- | arch/arm/mach-omap2/clock34xx.c | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/arch/arm/mach-omap2/clock34xx.c b/arch/arm/mach-omap2/clock34xx.c index 9e43fe5209d..045da923e75 100644 --- a/arch/arm/mach-omap2/clock34xx.c +++ b/arch/arm/mach-omap2/clock34xx.c @@ -286,6 +286,20 @@ static struct omap_clk omap34xx_clks[] = { #define MIN_SDRC_DLL_LOCK_FREQ 83000000 +#define CYCLES_PER_MHZ 1000000 + +/* Scale factor for fixed-point arith in omap3_core_dpll_m2_set_rate() */ +#define SDRC_MPURATE_SCALE 8 + +/* 2^SDRC_MPURATE_BASE_SHIFT: MPU MHz that SDRC_MPURATE_LOOPS is defined for */ +#define SDRC_MPURATE_BASE_SHIFT 9 + +/* + * SDRC_MPURATE_LOOPS: Number of MPU loops to execute at + * 2^MPURATE_BASE_SHIFT MHz for SDRC to stabilize + */ +#define SDRC_MPURATE_LOOPS 96 + /** * omap3_dpll_recalc - recalculate DPLL rate * @clk: DPLL struct clk @@ -709,7 +723,8 @@ static int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate) { u32 new_div = 0; u32 unlock_dll = 0; - unsigned long validrate, sdrcrate; + u32 c; + unsigned long validrate, sdrcrate, mpurate; struct omap_sdrc_params *sp; if (!clk || !rate) @@ -718,18 +733,15 @@ static int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate) 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); + sdrcrate <<= ((rate / clk->rate) >> 1); else - sdrcrate >>= ((clk->rate / rate) - 1); + sdrcrate >>= ((clk->rate / rate) >> 1); sp = omap2_sdrc_get_params(sdrcrate); if (!sp) @@ -740,17 +752,25 @@ static int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate) unlock_dll = 1; } + /* + * XXX This only needs to be done when the CPU frequency changes + */ + mpurate = arm_fck.rate / CYCLES_PER_MHZ; + c = (mpurate << SDRC_MPURATE_SCALE) >> SDRC_MPURATE_BASE_SHIFT; + c += 1; /* for safety */ + c *= SDRC_MPURATE_LOOPS; + c >>= SDRC_MPURATE_SCALE; + if (c == 0) + c = 1; + pr_debug("clock: changing CORE DPLL rate from %lu to %lu\n", clk->rate, validrate); pr_debug("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 */ omap3_configure_core_dpll(sp->rfr_ctrl, sp->actim_ctrla, - sp->actim_ctrlb, new_div, unlock_dll); + sp->actim_ctrlb, new_div, unlock_dll, c, + sp->mr, rate > clk->rate); return 0; } |