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clk: rockchip: reset init state before mmc card initialization 

mmc host controller's IO input/output timing is unpredictable if
bootloader execute tuning for HS200 mode. It might make kernel failed
to initialize mmc card in identification mode. The root cause is
tuning phase and degree setting for HS200 mode in bootloader aren't
applicable to that of identification mode in kernel stage. Anyway, we
can't force all bootloaders to reset tuning phase and degree setting
before into kernel. Simply reset it in rockchip_clk_register_mmc.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
This commit is contained in:
Shawn Lin 2015-09-04 08:15:33 +08:00 committed by Stephen Boyd
parent 7a29f3f020
commit 7a03fe6f48
1 changed files with 11 additions and 0 deletions
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11
drivers/clk/rockchip/clk-mmc-phase.c
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@ -41,6 +41,8 @@ static unsigned long rockchip_mmc_recalc(struct clk_hw *hw,
#define ROCKCHIP_MMC_DEGREE_MASK 0x3
#define ROCKCHIP_MMC_DELAYNUM_OFFSET 2
#define ROCKCHIP_MMC_DELAYNUM_MASK (0xff << ROCKCHIP_MMC_DELAYNUM_OFFSET)
#define ROCKCHIP_MMC_INIT_STATE_RESET 0x1
#define ROCKCHIP_MMC_INIT_STATE_SHIFT 1
#define PSECS_PER_SEC 1000000000000LL
@ -143,6 +145,15 @@ struct clk *rockchip_clk_register_mmc(const char *name,
mmc_clock->reg = reg;
mmc_clock->shift = shift;
/*
* Assert init_state to soft reset the CLKGEN
* for mmc tuning phase and degree
*/
if (mmc_clock->shift == ROCKCHIP_MMC_INIT_STATE_SHIFT)
writel(HIWORD_UPDATE(ROCKCHIP_MMC_INIT_STATE_RESET,
ROCKCHIP_MMC_INIT_STATE_RESET,
mmc_clock->shift), mmc_clock->reg);
clk = clk_register(NULL, &mmc_clock->hw);
if (IS_ERR(clk))
goto err_free;