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path: root/drivers/i2c/busses/i2c-stm32f4.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-stm32f4.c')
-rw-r--r--drivers/i2c/busses/i2c-stm32f4.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/drivers/i2c/busses/i2c-stm32f4.c b/drivers/i2c/busses/i2c-stm32f4.c
index ba600d77a3f8..d6a69dfcac3f 100644
--- a/drivers/i2c/busses/i2c-stm32f4.c
+++ b/drivers/i2c/busses/i2c-stm32f4.c
@@ -232,10 +232,10 @@ static void stm32f4_i2c_set_speed_mode(struct stm32f4_i2c_dev *i2c_dev)
* In standard mode:
* t_scl_high = t_scl_low = CCR * I2C parent clk period
* So to reach 100 kHz, we have:
- * CCR = I2C parent rate / 100 kHz >> 1
+ * CCR = I2C parent rate / (100 kHz * 2)
*
* For example with parent rate = 2 MHz:
- * CCR = 2000000 / (100000 << 1) = 10
+ * CCR = 2000000 / (100000 * 2) = 10
* t_scl_high = t_scl_low = 10 * (1 / 2000000) = 5000 ns
* t_scl_high + t_scl_low = 10000 ns so 100 kHz is reached
*
@@ -243,7 +243,7 @@ static void stm32f4_i2c_set_speed_mode(struct stm32f4_i2c_dev *i2c_dev)
* parent rate is not higher than 46 MHz . As a result val
* is at most 8 bits wide and so fits into the CCR bits [11:0].
*/
- val = i2c_dev->parent_rate / (100000 << 1);
+ val = i2c_dev->parent_rate / (I2C_MAX_STANDARD_MODE_FREQ * 2);
} else {
/*
* In fast mode, we compute CCR with duty = 0 as with low
@@ -263,7 +263,7 @@ static void stm32f4_i2c_set_speed_mode(struct stm32f4_i2c_dev *i2c_dev)
* parent rate is not higher than 46 MHz . As a result val
* is at most 6 bits wide and so fits into the CCR bits [11:0].
*/
- val = DIV_ROUND_UP(i2c_dev->parent_rate, 400000 * 3);
+ val = DIV_ROUND_UP(i2c_dev->parent_rate, I2C_MAX_FAST_MODE_FREQ * 3);
/* Select Fast mode */
ccr |= STM32F4_I2C_CCR_FS;
@@ -807,7 +807,7 @@ static int stm32f4_i2c_probe(struct platform_device *pdev)
i2c_dev->speed = STM32_I2C_SPEED_STANDARD;
ret = of_property_read_u32(np, "clock-frequency", &clk_rate);
- if (!ret && clk_rate >= 400000)
+ if (!ret && clk_rate >= I2C_MAX_FAST_MODE_FREQ)
i2c_dev->speed = STM32_I2C_SPEED_FAST;
i2c_dev->dev = &pdev->dev;