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From: Loic Poulain <loic.poulain@oss.qualcomm.com>
To: Robert Foss <rfoss@kernel.org>,
	Andi Shyti <andi.shyti@kernel.org>,
	Wolfram Sang <wsa+renesas@sang-engineering.com>,
	Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>,
	Luca Weiss <luca@lucaweiss.eu>
Cc: linux-i2c@vger.kernel.org, linux-arm-msm@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Loic Poulain <loic.poulain@oss.qualcomm.com>
Subject: [PATCH 1/3] Revert "i2c: qcom-cci: Remove unused struct member cci_clk_rate"
Date: Tue, 21 Jul 2026 16:58:19 +0200	[thread overview]
Message-ID: <20260721-cci-clk-fix-v1-1-5eae78700da8@oss.qualcomm.com> (raw)
In-Reply-To: <20260721-cci-clk-fix-v1-0-5eae78700da8@oss.qualcomm.com>

This reverts commit b641af684fc28a07bee9c808eb6c433f9d9bcec6.

The cci_clk_rate field is needed to enforce the correct CCI clock rate
at probe time. The hw_params timing values are in clock ticks and were
calibrated for a specific frequency per hardware variant, so running at
the wrong rate would violate I2C timing specifications.

Signed-off-by: Loic Poulain <loic.poulain@oss.qualcomm.com>
---
 drivers/i2c/busses/i2c-qcom-cci.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/i2c/busses/i2c-qcom-cci.c b/drivers/i2c/busses/i2c-qcom-cci.c
index 4d64895a9e9e4e0bd5e0ccb5c3cc04b282b1e4d5..19e4719f13b29b2cf60e113565b1b63f19d0e669 100644
--- a/drivers/i2c/busses/i2c-qcom-cci.c
+++ b/drivers/i2c/busses/i2c-qcom-cci.c
@@ -117,6 +117,7 @@ struct cci_data {
 	unsigned int num_masters;
 	struct i2c_adapter_quirks quirks;
 	u16 queue_size[NUM_QUEUES];
+	unsigned long cci_clk_rate;
 	struct hw_params params[3];
 };
 
@@ -668,6 +669,7 @@ static const struct cci_data cci_v1_data = {
 		.max_write_len = 10,
 		.max_read_len = 12,
 	},
+	.cci_clk_rate =  19200000,
 	.params[I2C_MODE_STANDARD] = {
 		.thigh = 78,
 		.tlow = 114,
@@ -701,6 +703,7 @@ static const struct cci_data cci_v1_5_data = {
 		.max_write_len = 10,
 		.max_read_len = 12,
 	},
+	.cci_clk_rate =  19200000,
 	.params[I2C_MODE_STANDARD] = {
 		.thigh = 78,
 		.tlow = 114,
@@ -734,6 +737,7 @@ static const struct cci_data cci_v2_data = {
 		.max_write_len = 11,
 		.max_read_len = 12,
 	},
+	.cci_clk_rate =  37500000,
 	.params[I2C_MODE_STANDARD] = {
 		.thigh = 201,
 		.tlow = 174,

-- 
2.34.1


  reply	other threads:[~2026-07-21 14:58 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-21 14:58 [PATCH 0/3] i2c: qcom-cci: Fix CCI clock rate enforcement Loic Poulain
2026-07-21 14:58 ` Loic Poulain [this message]
2026-07-24 22:57   ` [PATCH 1/3] Revert "i2c: qcom-cci: Remove unused struct member cci_clk_rate" Andi Shyti
2026-07-25  5:41     ` Vladimir Zapolskiy
2026-07-25  8:40     ` Vladimir Zapolskiy
2026-07-26 15:08       ` Andi Shyti
2026-07-21 14:58 ` [PATCH 2/3] i2c: qcom-cci: Add missing cci_clk_rate for msm8953 Loic Poulain
2026-07-25  6:42   ` Vladimir Zapolskiy
2026-07-25  8:36   ` Vladimir Zapolskiy
2026-07-25 13:06     ` Loic Poulain
2026-07-25 14:19       ` Vladimir Zapolskiy
2026-07-21 14:58 ` [PATCH 3/3] i2c: qcom-cci: Fix CCI clock rate enforcement Loic Poulain
2026-07-21 15:07   ` Konrad Dybcio
2026-07-21 15:41     ` Loic Poulain
2026-07-21 17:01       ` Konrad Dybcio
2026-07-23  3:04 ` [PATCH 0/3] " Wenmeng Liu

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