diff mbox series

[v6,1/5] i2c: qcom-cci: Switch msm8953 to the CCI v2 timing/rate config

Message ID 20260929-cci-clk-fix-v6-1-62a268cccb0f@oss.qualcomm.com
State Accepted
Delegated to: Andi Shyti
Headers show
Series i2c: qcom-cci: Enforce the required CCI clock rate | expand

Commit Message

Loic Poulain Sept. 29, 2026, 12:25 p.m. UTC 
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.

Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 drivers/i2c/busses/i2c-qcom-cci.c | 47 +--------------------------------------
 1 file changed, 1 insertion(+), 46 deletions(-)
diff mbox series

Patch

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},