diff options
| author | huang lin <hl@rock-chips.com> | 2014-10-10 23:26:21 -0700 |
|---|---|---|
| committer | Aaron Durbin <adurbin@google.com> | 2015-04-04 15:04:39 +0200 |
| commit | 8affee58975f28e6a22fe3a474bd8bdd9a9cc05a (patch) | |
| tree | 7331f58026c20a19bedff8b511be004dfad622a0 /src/soc/rockchip/rk3288 | |
| parent | 45e16fc19913224c124cba0ca0ac22e949de9e9a (diff) | |
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 <hl@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/223002
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
(cherry picked from commit 57a5d90d394086483e0dcdd6279678658d07d842)
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Change-Id: I6b0c9dfa540354f6463ed90c9f3f9503a4d5749e
Reviewed-on: http://review.coreboot.org/9259
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src/soc/rockchip/rk3288')
| -rw-r--r-- | src/soc/rockchip/rk3288/i2c.c | 8 |
1 files changed, 4 insertions, 4 deletions
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); } |