2023-10-23 08:13:34

by Huangzheng Lai

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 <[email protected]>
---
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

2023-10-24 21:35:36

by Andi Shyti

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

On Mon, Oct 23, 2023 at 04:11:56PM +0800, Huangzheng Lai wrote:
> 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.

where is the timeout occurring? Is it a sporadic failure?

> Signed-off-by: Huangzheng Lai <[email protected]>

Would be nice if any from Orson, Boulin or Chunyan could take a
look here.

Andi