Hi, Currently, CSPI2 of the i.MX27 is used to communicate with its companion chip (MC13783). This works fine. The SPI parts of the board file look like : static int imx27_interaxio_spi1_cs[] = {GPIO_PORTD + 21}; static struct spi_imx_master imx27_interaxio_spi_1_data = { .chipselect = imx27_interaxio_spi1_cs, .num_chipselect = ARRAY_SIZE(imx27_interaxio_spi1_cs), }; static struct spi_board_info imx27_interaxio_spi_board_info[] = { { .name = "mc13783", .max_speed_hz = 3000000, .bus_num = 0, .chip_select = 0, /* offset in the chip select array */ }, }; […] static int imx27_interaxio_devices_init(void) { […] /* PMIC support */ spi_register_board_info(imx27_interaxio_spi_board_info, ARRAY_SIZE(imx27_interaxio_spi_board_info)); imx27_add_spi1(&imx27_interaxio_spi_1_data); […] Now, I would like to add another SPI port of the i.MX27, CSPI1, to control an LCD. To do that, I taught I had to change the board file like this : static int imx27_interaxio_spi1_cs[] = {GPIO_PORTD + 21}; static int imx27_interaxio_spi0_cs[] = {GPIO_PORTD + 28}; static struct spi_imx_master imx27_interaxio_spi_1_data = { .chipselect = imx27_interaxio_spi1_cs, .num_chipselect = ARRAY_SIZE(imx27_interaxio_spi1_cs), }; static struct spi_imx_master imx27_interaxio_spi_0_data = { .chipselect = imx27_interaxio_spi0_cs, .num_chipselect = ARRAY_SIZE(imx27_interaxio_spi0_cs), }; static struct spi_board_info imx27_interaxio_spi_board_info[] = { { .name = "mc13783", .max_speed_hz = 3000000, .bus_num = 0, .chip_select = 0, }, { .name = "LCD", .max_speed_hz = 2000000, .bus_num = 1, .chip_select = 0, }, }; […] static int imx27_interaxio_devices_init(void) { […] /* PMIC support */ spi_register_board_info(imx27_interaxio_spi_board_info, ARRAY_SIZE(imx27_interaxio_spi_board_info)); imx27_add_spi1(&imx27_interaxio_spi_1_data); imx27_add_spi0(&imx27_interaxio_spi_0_data); […] However, I’m not sure I’m doing it right. E.g. for the bus_num element. As it is another ‘master’, I guess it should get another bus number. However, when digging a little in the code, in imx_spi_probe (imx_spi.c), bus_num of ‘master’ is never initialized, so always 0. A little further, when scanning for board info (scan_boardinfo in spi.c), bus_num of chip is compared to bus_num of master, which is always 0. For the existing implementation this was not a problem as the bus_num in the board info struct was also 0. For the added bus, the bus_num is 1, so the compare will validate to false and the device will not be created… This is how I’m think it’s working. Am I correct ? Am I doing something wrong ? Should I also use bus_num 0 for my additional SPI instead of 1 ? Thanks in advance for helping me ! Filip Vanalme |
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