2023-08-19 15:08:33

by Huangzheng Lai

Subject: [PATCH 4/8] i2c: sprd: Add IIC controller driver to support dynamic switching of 400K/1M/3.4M frequency

When IIC-slaves supporting different frequencies use the same IIC
controller, the IIC controller usually only operates at lower frequencies.
In order to improve the performance of IIC-slaves transmission supporting
faster frequencies, we dynamically configure the IIC operating frequency
based on the value of the input parameter msg ->flag.

Signed-off-by: Huangzheng Lai <[email protected]>
---
drivers/i2c/busses/i2c-sprd.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-sprd.c b/drivers/i2c/busses/i2c-sprd.c
index 549b60dd3273..02c11a9ff2da 100644
--- a/drivers/i2c/busses/i2c-sprd.c
+++ b/drivers/i2c/busses/i2c-sprd.c
@@ -75,7 +75,14 @@
#define SPRD_I2C_PM_TIMEOUT 1000
/* timeout (ms) for transfer message */
#define I2C_XFER_TIMEOUT 1000
-
+/* dynamic modify clk_freq flag */
+#define I2C_3M4_FLAG 0x0100
+#define I2C_1M_FLAG 0x0080
+#define I2C_400K_FLAG 0x0040
+
+#define I2C_FREQ_400K 400000
+#define I2C_FREQ_1M 1000000
+#define I2C_FREQ_3_4M 3400000
/* SPRD i2c data structure */
struct sprd_i2c {
struct i2c_adapter adap;
@@ -94,6 +101,8 @@ struct sprd_i2c {
int err;
};

+static void sprd_i2c_set_clk(struct sprd_i2c *i2c_dev, u32 freq);
+
static void sprd_i2c_set_count(struct sprd_i2c *i2c_dev, u32 count)
{
writel(count, i2c_dev->base + I2C_COUNT);
@@ -269,6 +278,12 @@ static int sprd_i2c_handle_msg(struct i2c_adapter *i2c_adap,
sprd_i2c_send_stop(i2c_dev, !!is_last_msg);
}

+ if (msg->flags & I2C_400K_FLAG)
+ sprd_i2c_set_clk(i2c_dev, I2C_FREQ_400K);
+ else if (msg->flags & I2C_1M_FLAG)
+ sprd_i2c_set_clk(i2c_dev, I2C_FREQ_1M);
+ else if (msg->flags & I2C_3M4_FLAG)
+ sprd_i2c_set_clk(i2c_dev, I2C_FREQ_3_4M);
/*
* We should enable rx fifo full interrupt to get data when receiving
* full data.
--
2.17.1

2023-09-03 13:44:46

by Andi Shyti

Subject: Re: [PATCH 4/8] i2c: sprd: Add IIC controller driver to support dynamic switching of 400K/1M/3.4M frequency

Hi Chunyan,

[...]

> > When IIC-slaves supporting different frequencies use the same IIC
>
> %s/I2C/IIC

[...]

> > #define SPRD_I2C_PM_TIMEOUT 1000
> > /* timeout (ms) for transfer message */
> > #define I2C_XFER_TIMEOUT 1000
> > -
> > +/* dynamic modify clk_freq flag */
> > +#define I2C_3M4_FLAG 0x0100
>
> #define <space> I2C_3M4_FLAG <tab> 0x0100
>
> > +#define I2C_1M_FLAG 0x0080
> > +#define I2C_400K_FLAG 0x0040
> > +
> > +#define I2C_FREQ_400K 400000
> > +#define I2C_FREQ_1M 1000000
> > +#define I2C_FREQ_3_4M 3400000
>
> ditto

why should he use IIC instead of I2C. The file's defines start
with I2C, for consistency he should use the same prefix.

Andi

2023-09-06 07:05:42

by Andi Shyti

Subject: Re: [PATCH 4/8] i2c: sprd: Add IIC controller driver to support dynamic switching of 400K/1M/3.4M frequency

Hi Chunyan,

> > > > #define SPRD_I2C_PM_TIMEOUT 1000
> > > > /* timeout (ms) for transfer message */
> > > > #define I2C_XFER_TIMEOUT 1000
> > > > -
> > > > +/* dynamic modify clk_freq flag */
> > > > +#define I2C_3M4_FLAG 0x0100
> > >
> > > #define <space> I2C_3M4_FLAG <tab> 0x0100
> > >
> > > > +#define I2C_1M_FLAG 0x0080
> > > > +#define I2C_400K_FLAG 0x0040
> > > > +
> > > > +#define I2C_FREQ_400K 400000
> > > > +#define I2C_FREQ_1M 1000000
> > > > +#define I2C_FREQ_3_4M 3400000
> > >
> > > ditto
>
> I meant "#define <space> I2C_FREQ_3_4M <tab> 3400000"

right! Agree with your comment!

> >
> > why should he use IIC instead of I2C. The file's defines start
> > with I2C, for consistency he should use the same prefix.
> >
>
> Yes, I agree.

Thanks,
Andi