[PATCH v2 1/3] i2c: qcom-cci: Switch msm8953 to the CCI v2 timing/rate config
From: Loic Poulain
Date: Mon Jul 27 2026 - 05:22:13 EST
The msm8953 CCI timing table is internally inconsistent. Its Standard
and Fast timings match v1/v1.5, which are calibrated for a 19.2 MHz CCI
clock, but its Fast+ timings are essentially the v2 values, which are
calibrated for 37.5 MHz. Since all masters share a single CCI clock,
no single rate can satisfy all three modes with the current table, and
the DT assigns 19.2 MHz, so Fast+ timings are wrong.
The msm8953 CCI is the same hardware version as msm8996/sdm630, which
already use the cci_v2_data config (37.5 MHz). 37.5 MHz is supported by
the msm8953 CCI RCG, so reuse cci_v2_data for msm8953 as well and drop
the redundant, inconsistent standalone table. This makes all three I2C
modes self-consistent under a single clock rate.
Note this requires the CCI clock to run at 37.5 MHz, the proper clock
rate will be set in an upcoming CCI patch.
Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-qcom-cci.c | 47 +--------------------------------------
1 file changed, 1 insertion(+), 46 deletions(-)
diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
index 4d64895a9e9e4e0bd5e0ccb5c3cc04b282b1e4d5..23cef922351ce44d71f1691cd7e4aab274fdd196 100644
--- a/drivers/i2c/busses/i2c-qcom-cci.c
+++ b/drivers/i2c/busses/i2c-qcom-cci.c
@@ -772,54 +772,9 @@ static const struct cci_data cci_v2_data = {
},
};
-static const struct cci_data cci_msm8953_data = {
- .num_masters = 2,
- .queue_size = { 64, 16 },
- .quirks = {
- .max_write_len = 11,
- .max_read_len = 12,
- },
- .params[I2C_MODE_STANDARD] = {
- .thigh = 78,
- .tlow = 114,
- .tsu_sto = 28,
- .tsu_sta = 28,
- .thd_dat = 10,
- .thd_sta = 77,
- .tbuf = 118,
- .scl_stretch_en = 0,
- .trdhld = 6,
- .tsp = 1
- },
- .params[I2C_MODE_FAST] = {
- .thigh = 20,
- .tlow = 28,
- .tsu_sto = 21,
- .tsu_sta = 21,
- .thd_dat = 13,
- .thd_sta = 18,
- .tbuf = 32,
- .scl_stretch_en = 0,
- .trdhld = 6,
- .tsp = 3
- },
- .params[I2C_MODE_FAST_PLUS] = {
- .thigh = 16,
- .tlow = 22,
- .tsu_sto = 17,
- .tsu_sta = 18,
- .thd_dat = 16,
- .thd_sta = 15,
- .tbuf = 19,
- .scl_stretch_en = 1,
- .trdhld = 3,
- .tsp = 3
- },
-};
-
static const struct of_device_id cci_dt_match[] = {
{ .compatible = "qcom,msm8226-cci", .data = &cci_v1_data},
- { .compatible = "qcom,msm8953-cci", .data = &cci_msm8953_data},
+ { .compatible = "qcom,msm8953-cci", .data = &cci_v2_data},
{ .compatible = "qcom,msm8974-cci", .data = &cci_v1_5_data},
{ .compatible = "qcom,msm8996-cci", .data = &cci_v2_data},
--
2.34.1