linux-kernel - [PATCH V2 5/7] i2c: sprd: Configure the enable bit of the I2C controller before each transmission initiation

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Message-ID: <20230921085457.32446-6-Huangzheng.Lai@unisoc.com>
Date:   Thu, 21 Sep 2023 16:54:55 +0800
From:   Huangzheng Lai <Huangzheng.Lai@...soc.com>
To:     Andi Shyti <andi.shyti@...nel.org>
CC:     Orson Zhai <orsonzhai@...il.com>,
        Baolin Wang <baolin.wang@...ux.alibaba.com>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        <linux-i2c@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        huangzheng lai <laihuangzheng@...il.com>,
        Huangzheng Lai <Huangzheng.Lai@...soc.com>,
        Xiongpeng Wu <xiongpeng.wu@...soc.com>
Subject: [PATCH V2 5/7] i2c: sprd: Configure the enable bit of the I2C controller before each transmission initiation

When a timeout exception occurs in the I2C driver, the I2C controller
will be reset, and after resetting, control bits such as I2C_EN and
I2C_INT_EN will be reset to 0, and the I2C master cannot initiate
Transmission unless sprd_i2c_enable() is executed. To address this issue,
this patch places sprd_i2c_enable() before each transmission initiation
to ensure that the necessary control bits of the I2C controller are
configured.

Signed-off-by: Huangzheng Lai <Huangzheng.Lai@...soc.com>
---
 drivers/i2c/busses/i2c-sprd.c | 38 +++++++++++++++++------------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
index f1f7fad42ecd..b65729ba7d5a 100644
--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -352,6 +352,23 @@ static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap,
 	return i2c_dev->err;
 }
 
+static void sprd_i2c_enable(struct sprd_i2c *i2c_dev)
+{
+	u32 tmp = I2C_DVD_OPT;
+
+	writel(tmp, i2c_dev->base + I2C_CTL);
+
+	sprd_i2c_set_full_thld(i2c_dev, I2C_FIFO_FULL_THLD);
+	sprd_i2c_set_empty_thld(i2c_dev, I2C_FIFO_EMPTY_THLD);
+
+	sprd_i2c_set_clk(i2c_dev, i2c_dev->bus_freq);
+	sprd_i2c_reset_fifo(i2c_dev);
+	sprd_i2c_clear_irq(i2c_dev);
+
+	tmp = readl(i2c_dev->base + I2C_CTL);
+	writel(tmp | I2C_EN | I2C_INT_EN, i2c_dev->base + I2C_CTL);
+}
+
 static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,
 				struct i2c_msg *msgs, int num)
 {
@@ -362,6 +379,8 @@ static int sprd_i2c_master_xfer(struct i2c_adapter *i2c_adap,
 	if (ret < 0)
 		return ret;
 
+	sprd_i2c_enable(i2c_dev);
+
 	for (im = 0; im < num - 1; im++) {
 		ret = sprd_i2c_handle_msg(i2c_adap, &msgs[im], 0);
 		if (ret)
@@ -387,23 +406,6 @@ static const struct i2c_algorithm sprd_i2c_algo = {
 	.functionality = sprd_i2c_func,
 };
 
-static void sprd_i2c_enable(struct sprd_i2c *i2c_dev)
-{
-	u32 tmp = I2C_DVD_OPT;
-
-	writel(tmp, i2c_dev->base + I2C_CTL);
-
-	sprd_i2c_set_full_thld(i2c_dev, I2C_FIFO_FULL_THLD);
-	sprd_i2c_set_empty_thld(i2c_dev, I2C_FIFO_EMPTY_THLD);
-
-	sprd_i2c_set_clk(i2c_dev, i2c_dev->bus_freq);
-	sprd_i2c_reset_fifo(i2c_dev);
-	sprd_i2c_clear_irq(i2c_dev);
-
-	tmp = readl(i2c_dev->base + I2C_CTL);
-	writel(tmp | I2C_EN | I2C_INT_EN, i2c_dev->base + I2C_CTL);
-}
-
 static irqreturn_t sprd_i2c_isr_thread(int irq, void *dev_id)
 {
 	struct sprd_i2c *i2c_dev = dev_id;
@@ -669,8 +671,6 @@ static int __maybe_unused sprd_i2c_runtime_resume(struct device *dev)
 	if (ret)
 		return ret;
 
-	sprd_i2c_enable(i2c_dev);
-
 	return 0;
 }
 
-- 
2.17.1