From 8affee58975f28e6a22fe3a474bd8bdd9a9cc05a Mon Sep 17 00:00:00 2001 From: huang lin Date: Fri, 10 Oct 2014 23:26:21 -0700 Subject: rk3288: guarantee i2c low period more than 1.3us change i2c clock low period and high period proportion to 7:3 guarantee the low period more than 1.3us BUG=None TEST=Boot on veyron_pinky rev2,check the i2c clock frequency Original-Change-Id: I235e9e3ff54ab3b9cabad36bab58a8409f7005a0 Original-Signed-off-by: huang lin Original-Reviewed-on: https://chromium-review.googlesource.com/223002 Original-Reviewed-by: Julius Werner (cherry picked from commit 57a5d90d394086483e0dcdd6279678658d07d842) Signed-off-by: Aaron Durbin Change-Id: I6b0c9dfa540354f6463ed90c9f3f9503a4d5749e Reviewed-on: http://review.coreboot.org/9259 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/soc/rockchip/rk3288/i2c.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'src/soc/rockchip/rk3288') diff --git a/src/soc/rockchip/rk3288/i2c.c b/src/soc/rockchip/rk3288/i2c.c index 142ec4a489..eb480a7d30 100644 --- a/src/soc/rockchip/rk3288/i2c.c +++ b/src/soc/rockchip/rk3288/i2c.c @@ -284,7 +284,7 @@ void i2c_init(unsigned int bus, unsigned int hz) unsigned int clk_div; unsigned int divl; unsigned int divh; - unsigned int i2c_src_clk; + unsigned int i2c_src_clk = 0; struct rk3288_i2c_regs *regs = i2c_bus[bus]; /*i2c0,i2c2 src clk from pd_bus_pclk @@ -308,9 +308,9 @@ void i2c_init(unsigned int bus, unsigned int hz) /*SCL Divisor = 8*(CLKDIVL + 1 + CLKDIVH + 1) SCL = PCLK/ SCLK Divisor */ - clk_div = div_round_up(i2c_src_clk, hz * 8) - 2; - divh = clk_div / 2; - divl = ALIGN_UP(clk_div, 2) / 2; + clk_div = div_round_up(i2c_src_clk, hz * 8); + divh = clk_div * 3 / 7 - 1; + divl = clk_div - divh - 2; assert((divh < 65536) && (divl < 65536)); writel((divh << 16) | (divl << 0), ®s->i2c_clkdiv); } -- cgit v1.2.3