From d0ba3922ae241a87d22a1c3ffad72b96fe993c9a Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Fri, 19 Jun 2009 19:08:27 -0600 Subject: [PATCH] OMAP3 clock/SDRC: program SDRC_MR register during SDRC clock change Program the SDRC_MR_0 register as well during SDRC clock changes. This register allows selection of the memory CAS latency. Some SDRAM chips, such as the Qimonda HYB18M512160AF6, have a lower CAS latency at lower clock rates. Signed-off-by: Paul Walmsley --- arch/arm/mach-omap2/clock34xx.c | 4 ++-- arch/arm/mach-omap2/sram34xx.S | 8 +++++++- arch/arm/plat-omap/include/mach/sram.h | 4 ++-- arch/arm/plat-omap/sram.c | 6 +++--- 4 files changed, 14 insertions(+), 8 deletions(-) diff --git a/arch/arm/mach-omap2/clock34xx.c b/arch/arm/mach-omap2/clock34xx.c index 4bfa650..cf41ab5 100644 --- a/arch/arm/mach-omap2/clock34xx.c +++ b/arch/arm/mach-omap2/clock34xx.c @@ -771,9 +771,9 @@ static int omap3_core_dpll_m2_set_rate(struct clk *clk, unsigned long rate) /* 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, c); + sp->actim_ctrlb, new_div, unlock_dll, c, + sp->mr); return 0; } diff --git a/arch/arm/mach-omap2/sram34xx.S b/arch/arm/mach-omap2/sram34xx.S index 8d4a88c..d13f1cc 100644 --- a/arch/arm/mach-omap2/sram34xx.S +++ b/arch/arm/mach-omap2/sram34xx.S @@ -44,12 +44,14 @@ * SDRC rates < 83MHz * r5 = number of MPU cycles to wait for SDRC to stabilize after * reprogramming the SDRC when switching to a slower MPU speed + * r6 = SDRC_MR_0 register value * */ ENTRY(omap3_sram_configure_core_dpll) stmfd sp!, {r1-r12, lr} @ store regs to stack ldr r4, [sp, #52] @ pull extra args off the stack ldr r5, [sp, #56] @ load extra args from the stack + ldr r6, [sp, #60] @ load extra args from the stack dsb @ flush buffered writes to interconnect cmp r3, #0x2 blne configure_sdrc @@ -151,7 +153,9 @@ configure_sdrc: str r1, [r11] ldr r11, omap3_sdrc_actim_ctrlb str r2, [r11] - ldr r2, [r11] @ posted-write barrier for SDRC + ldr r11, omap3_sdrc_mr_0 + str r6, [r11] + ldr r6, [r11] @ posted-write barrier for SDRC bx lr omap3_sdrc_power: @@ -168,6 +172,8 @@ omap3_sdrc_actim_ctrla: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_A_0) omap3_sdrc_actim_ctrlb: .word OMAP34XX_SDRC_REGADDR(SDRC_ACTIM_CTRL_B_0) +omap3_sdrc_mr_0: + .word OMAP34XX_SDRC_REGADDR(SDRC_MR_0) omap3_sdrc_dlla_status: .word OMAP34XX_SDRC_REGADDR(SDRC_DLLA_STATUS) omap3_sdrc_dlla_ctrl: diff --git a/arch/arm/plat-omap/include/mach/sram.h b/arch/arm/plat-omap/include/mach/sram.h index c32fa0a..4f87056 100644 --- a/arch/arm/plat-omap/include/mach/sram.h +++ b/arch/arm/plat-omap/include/mach/sram.h @@ -24,7 +24,7 @@ extern u32 omap2_set_prcm(u32 dpll_ctrl_val, u32 sdrc_rfr_val, int bypass); extern u32 omap3_configure_core_dpll(u32 sdrc_rfr_ctrl, u32 sdrc_actim_ctrla, u32 sdrc_actim_ctrlb, u32 m2, - u32 unlock_dll, u32 f); + u32 unlock_dll, u32 f, u32 sdrc_mr); /* Do not use these */ extern void omap1_sram_reprogram_clock(u32 ckctl, u32 dpllctl); @@ -62,7 +62,7 @@ extern unsigned long omap243x_sram_reprogram_sdrc_sz; extern u32 omap3_sram_configure_core_dpll(u32 sdrc_rfr_ctrl, u32 sdrc_actim_ctrla, u32 sdrc_actim_ctrlb, u32 m2, - u32 unlock_dll, u32 f); + u32 unlock_dll, u32 f, u32 sdrc_mr); extern unsigned long omap3_sram_configure_core_dpll_sz; #endif diff --git a/arch/arm/plat-omap/sram.c b/arch/arm/plat-omap/sram.c index 79c0f02..7dadf1a 100644 --- a/arch/arm/plat-omap/sram.c +++ b/arch/arm/plat-omap/sram.c @@ -372,16 +372,16 @@ static u32 (*_omap3_sram_configure_core_dpll)(u32 sdrc_rfr_ctrl, u32 sdrc_actim_ctrla, u32 sdrc_actim_ctrlb, u32 m2, u32 unlock_dll, - u32 f); + u32 f, u32 sdrc_mr); u32 omap3_configure_core_dpll(u32 sdrc_rfr_ctrl, u32 sdrc_actim_ctrla, u32 sdrc_actim_ctrlb, u32 m2, u32 unlock_dll, - u32 f) + u32 f, u32 sdrc_mr) { BUG_ON(!_omap3_sram_configure_core_dpll); return _omap3_sram_configure_core_dpll(sdrc_rfr_ctrl, sdrc_actim_ctrla, sdrc_actim_ctrlb, m2, - unlock_dll, f); + unlock_dll, f, sdrc_mr); } /* REVISIT: Should this be same as omap34xx_sram_init() after off-idle? */ -- 2.7.4