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| author | Karl Palsson <karlp@tweak.net.au> | 2017-10-27 00:54:30 +0300 |
|---|---|---|
| committer | Karl Palsson <karlp@etactica.com> | 2018-01-08 14:16:24 +0300 |
| commit | ed90df85f089d260fc598cb200b5d36678045ec0 (patch) | |
| tree | d82f4723485615cd8f0a5f8c15b6bf64f0c9c638 /lib | |
| parent | 965d28ecbec5df5b77f7a93222e0eb8d79c4c79c (diff) | |
stm32:i2c-v2: Clarify digital filter setting
Drop redundant field definitions, fix truncation of argument bug and add
documentation.
Fixes: https://github.com/libopencm3/libopencm3/issues/831
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/stm32/common/i2c_common_v2.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/lib/stm32/common/i2c_common_v2.c b/lib/stm32/common/i2c_common_v2.c index 2116064f..04ae7623 100644 --- a/lib/stm32/common/i2c_common_v2.c +++ b/lib/stm32/common/i2c_common_v2.c @@ -188,9 +188,18 @@ void i2c_disable_analog_filter(uint32_t i2c) I2C_CR1(i2c) |= I2C_CR1_ANFOFF; } +/** + * Set the I2C digital filter. + * These bits are used to configure the digital noise filter on SDA and + * SCL input. The digital filter will filter spikes with a length of up + * to dnf_setting * I2CCLK clocks + * @param i2c peripheral of interest + * @param dnf_setting 0 to disable, else 1..15 i2c clocks + */ void i2c_set_digital_filter(uint32_t i2c, uint8_t dnf_setting) { - I2C_CR1(i2c) = (I2C_CR1(i2c) & ~I2C_CR1_DNF_MASK) | dnf_setting; + I2C_CR1(i2c) = (I2C_CR1(i2c) & ~(I2C_CR1_DNF_MASK << I2C_CR1_DNF_SHIFT)) | + (dnf_setting << I2C_CR1_DNF_SHIFT); } /* t_presc= (presc+1)*t_i2cclk */ |