[coreboot-gerrit] New patch to review for coreboot: 1f34b77 rk3288: guarantee i2c low period more than 1.3us
Aaron Durbin (adurbin@google.com)
gerrit at coreboot.org
Thu Apr 2 23:33:28 CEST 2015
Aaron Durbin (adurbin at google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9259
-gerrit
commit 1f34b776d66704ad5eaf1cda327111da243d220b
Author: huang lin <hl at rock-chips.com>
Date: Fri Oct 10 23:26:21 2014 -0700
rk3288: guarantee i2c low period more than 1.3us
change i2c clock low period and high perid propoton 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 at rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/223002
Original-Reviewed-by: Julius Werner <jwerner at chromium.org>
(cherry picked from commit 57a5d90d394086483e0dcdd6279678658d07d842)
Signed-off-by: Aaron Durbin <adurbin at chromium.org>
Change-Id: I6b0c9dfa540354f6463ed90c9f3f9503a4d5749e
---
src/soc/rockchip/rk3288/i2c.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/src/soc/rockchip/rk3288/i2c.c b/src/soc/rockchip/rk3288/i2c.c
index 142ec4a..eb480a7 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);
}
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