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| author | Kevin O'Connor <kevin@koconnor.net> | 2021-11-20 13:47:17 -0500 |
|---|---|---|
| committer | Kevin O'Connor <kevin@koconnor.net> | 2021-11-20 13:52:16 -0500 |
| commit | bb08dc7ae91488a6e9e1e88de28bd43be9fa5651 (patch) | |
| tree | 0f8255ecf3f5d4bd4a9b66db302795071533ba64 /src/atsam/spi.c | |
| parent | 92ca1119868abbd859c8f7a3f88143cf53561eb3 (diff) | |
| download | kutter-bb08dc7ae91488a6e9e1e88de28bd43be9fa5651.tar.gz kutter-bb08dc7ae91488a6e9e1e88de28bd43be9fa5651.tar.xz kutter-bb08dc7ae91488a6e9e1e88de28bd43be9fa5651.zip | |
atsam: Add get_pclock_frequency() helper function
Add get_pclock_frequency() and use it to calculate peripheral clocks.
Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
Diffstat (limited to 'src/atsam/spi.c')
| -rw-r--r-- | src/atsam/spi.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/src/atsam/spi.c b/src/atsam/spi.c index d64f0df7..e32085df 100644 --- a/src/atsam/spi.c +++ b/src/atsam/spi.c @@ -123,19 +123,18 @@ spihw_setup(uint32_t bus, uint8_t mode, uint32_t rate) // Make sure bus is enabled spihw_init(bus); - uint32_t config = 0; - uint32_t clockDiv; - if (rate < (CHIP_FREQ_CPU_MAX / 255)) { + uint32_t clockDiv, pclk = get_pclock_frequency(ID_USART0); + if (rate < pclk / 255) { clockDiv = 255; - } else if (rate >= (CHIP_FREQ_CPU_MAX / 2)) { + } else if (rate >= pclk / 2) { clockDiv = 2; } else { - clockDiv = (CHIP_FREQ_CPU_MAX / (rate + 1)) + 1; + clockDiv = pclk / (rate + 1) + 1; } /****** Will be written to SPI_CSRx register ******/ // CSAAT : Chip Select Active After Transfer - config = SPI_CSR_CSAAT; + uint32_t config = SPI_CSR_CSAAT; config |= SPI_CSR_BITS_8_BIT; // TODO: support for SPI_CSR_BITS_16_BIT // NOTE: NCPHA is inverted, CPHA normal!! switch(mode) { @@ -208,7 +207,8 @@ usart_setup(uint32_t bus, uint8_t mode, uint32_t rate) p_usart->US_CR = US_CR_RSTTX | US_CR_RSTRX | US_CR_TXDIS | US_CR_RXDIS; - uint32_t br = DIV_ROUND_UP(CHIP_FREQ_CPU_MAX, rate); + uint32_t pclk = get_pclock_frequency(ID_USART0); + uint32_t br = DIV_ROUND_UP(pclk, rate); p_usart->US_BRGR = br << US_BRGR_CD_Pos; uint32_t reg = US_MR_CHRL_8_BIT | |