[U-Boot] [PATCH 15/33] rockchip: clk: rk3288: fix mmc clock setting

Ziyuan Xu xzy.xu at rock-chips.com
Mon May 15 06:07:09 UTC 2017


Mmc clock automatically divide 2 in internal.

Before this:
gpll = 594MHz, clock = 148.5MHz
div = 594/148.5-1 = 3
output clock is 99MHz

After this:
gpll = 594MHz, clock = 148.5MHz
div = 297+148.5-1/148.5 = 2
output clock is 148.5Mhz

Signed-off-by: Ziyuan Xu <xzy.xu at rock-chips.com>
---

 drivers/clk/rockchip/clk_rk3288.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/rockchip/clk_rk3288.c b/drivers/clk/rockchip/clk_rk3288.c
index fc369dd..b924a3b 100644
--- a/drivers/clk/rockchip/clk_rk3288.c
+++ b/drivers/clk/rockchip/clk_rk3288.c
@@ -535,7 +535,7 @@ static ulong rockchip_mmc_get_clk(struct rk3288_cru *cru, uint gclk_rate,
 	}
 
 	src_rate = mux == EMMC_PLL_SELECT_24MHZ ? OSC_HZ : gclk_rate;
-	return DIV_TO_RATE(src_rate, div);
+	return DIV_TO_RATE(src_rate, div) / 2;
 }
 
 static ulong rockchip_mmc_set_clk(struct rk3288_cru *cru, uint gclk_rate,
@@ -545,10 +545,10 @@ static ulong rockchip_mmc_set_clk(struct rk3288_cru *cru, uint gclk_rate,
 	int mux;
 
 	debug("%s: gclk_rate=%u\n", __func__, gclk_rate);
-	src_clk_div = RATE_TO_DIV(gclk_rate, freq);
+	src_clk_div = DIV_ROUND_UP(gclk_rate / 2, freq);
 
 	if (src_clk_div > 0x3f) {
-		src_clk_div = RATE_TO_DIV(OSC_HZ, freq);
+		src_clk_div = DIV_ROUND_UP(OSC_HZ / 2, freq);
 		mux = EMMC_PLL_SELECT_24MHZ;
 		assert((int)EMMC_PLL_SELECT_24MHZ ==
 		       (int)MMC0_PLL_SELECT_24MHZ);
-- 
2.7.4




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