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 <Huangzheng.Lai@xxxxxxxxxx>
---
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
