michaelh/zephyr
1
0
Fork 0
Code Releases Activity

drivers: spi: Add default char to mcux flexcomm spi driver

Browse source 
Adds optional device tree property to specify a default character
to clock out when the TX buffer pointer is NULL. If the property is
not set the existing behavior (default char of 0x00) is used.

I verified the expected behavior using an i.MX RT685 board and
logic analyzer that the def-char character is transmitted when
TX buffer pointer is NULL.

Signed-off-by: Bryce Wilkins <bryce.wilkins@gmail.com>
This commit is contained in:
Bryce Wilkins 2022-07-28 16:20:08 -07:00 • committed by Mahesh Mahadevan
commit 5ff80ef2b1
2 changed files with 13 additions and 1 deletions
Download patch file Download diff file Expand all files Collapse all files

7
drivers/spi/spi_mcux_flexcomm.c
View file

@ -36,6 +36,7 @@ struct spi_mcux_config {
uint32_t post_delay;
uint32_t frame_delay;
uint32_t transfer_delay;
uint32_t def_char;
#ifdef CONFIG_PINCTRL
const struct pinctrl_dev_config *pincfg;
#endif
@ -247,9 +248,10 @@ static int spi_mcux_configure(const struct device *dev,
SPI_MasterInit(base, &master_config, clock_freq);
SPI_SetDummyData(base, (uint8_t)config->def_char);
SPI_MasterTransferCreateHandle(base, &data->handle,
spi_mcux_transfer_callback, data);
SPI_SetDummyData(base, 0);
data->ctx.config = spi_cfg;
} else {
@ -278,6 +280,8 @@ static int spi_mcux_configure(const struct device *dev,
SPI_SlaveInit(base, &slave_config);
SPI_SetDummyData(base, (uint8_t)config->def_char);
SPI_SlaveTransferCreateHandle(base, &data->handle,
spi_mcux_transfer_callback, data);
}
@ -823,6 +827,7 @@ static void spi_mcux_config_func_##id(const struct device *dev) \
.post_delay = DT_INST_PROP_OR(id, post_delay, 0), \
.frame_delay = DT_INST_PROP_OR(id, frame_delay, 0), \
.transfer_delay = DT_INST_PROP_OR(id, transfer_delay, 0), \
.def_char = DT_INST_PROP_OR(id, def_char, 0), \
SPI_MCUX_FLEXCOMM_PINCTRL_INIT(id) \
}; \
static struct spi_mcux_data spi_mcux_data_##id = { \

7
dts/bindings/spi/nxp,lpc-spi.yaml
View file

@ -36,3 +36,10 @@ properties:
description: |
Delay in nanoseconds inserted between transfers when chip select is
deasserted. If not set, no additional delay is inserted.
def-char:
type: int
required: false
description: |
Default character clocked out when the TX buffer pointer is NULL.
Applies to SPI master and slave configurations.