[PATCH] i2c: qcom-geni: restore tSCL with 32MHz I2C fast-mode

[PATCH] i2c: qcom-geni: restore tSCL with 32MHz I2C fast-mode

[Daniel J Blueman]

Commit cb97bf3d4f91 ("i2c: qcom-geni: Fix hardcoded clock index in
SE_GENI_CLK_SEL") allowed GENI to use 32MHz clock. This changed I2C
timing, making the Yoga Slim 7x keyboard (ITE 048D:8987) unusable
on all boots, and touchpad unusable on some boots, resulting in:

  i2c_hid_of 1-003a: unexpected HID descriptor bcdVersion (0x0000)
  i2c_hid_of 1-002c: failed to fetch HID descriptor: -110

With this change, t_high_cnt 3 and clk_div 4 gave a tSCL of 375ns
versus the previous default of 521ns, however the I2C spec has a
minimum tSCL of 600ns.

Restore tSCL to the spec with t_high_cnt 5 giving a 625ns tSCL,
verified on Lenovo Yoga Slim 7x X1E-80100.

Fixes: 506bb2ab0075 ("i2c: qcom-geni: Support systems with 32MHz serial engine clock")
Cc: <stable@vger.kernel.org>
Signed-off-by: Daniel J Blueman <daniel@quora.org>
---
 drivers/i2c/busses/i2c-qcom-geni.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-qcom-geni.c b/drivers/i2c/busses/i2c-qcom-geni.c
index 6a39e21d5ed4..1336a09ca183 100644
--- a/drivers/i2c/busses/i2c-qcom-geni.c
+++ b/drivers/i2c/busses/i2c-qcom-geni.c
@@ -193,7 +193,7 @@ static const struct geni_i2c_clk_fld geni_i2c_clk_map_19p2mhz[] = {
 /* source_clock = 32 MHz */
 static const struct geni_i2c_clk_fld geni_i2c_clk_map_32mhz[] = {
 	{ I2C_MAX_STANDARD_MODE_FREQ, 12, 9, 10, 26 },
-	{ I2C_MAX_FAST_MODE_FREQ, 4, 3, 9, 19 },
+	{ I2C_MAX_FAST_MODE_FREQ, 4, 5, 9, 19 },
 	{ I2C_MAX_FAST_MODE_PLUS_FREQ, 2, 3, 5, 15 },
 	{}
 };
-- 
2.53.0