[PATCH v4 1/5] i2c: qcom-cci: Switch msm8953 to the CCI v2 timing/rate config
Loic Poulain <[email protected]> Sat, 01 Aug 2026 22:10:43 +0200
| Newsgroups | org.kernel.vger.linux-i2c,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
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 driver selects and enforces the proper rate in following patches. Signed-off-by: Loic Poulain <[email protected]> --- 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 bdeda3979c4814b5cdb463734b8361da7fffa879..0a216c4d08114f267c8441925e8811ca64f1a909 100644 --- a/drivers/i2c/busses/i2c-qcom-cci.c +++ b/drivers/i2c/busses/i2c-qcom-cci.c @@ -756,54 +756,9 @@ 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