diff options
Diffstat (limited to 'drivers/spi/spi-davinci.c')
| -rw-r--r-- | drivers/spi/spi-davinci.c | 50 |
1 files changed, 40 insertions, 10 deletions
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index 987afebea093..3cf9faa6cc3f 100644 --- a/drivers/spi/spi-davinci.c +++ b/drivers/spi/spi-davinci.c @@ -139,6 +139,8 @@ struct davinci_spi { u32 (*get_tx)(struct davinci_spi *); u8 *bytes_per_word; + + u8 prescaler_limit; }; static struct davinci_spi_config davinci_spi_default_cfg; @@ -255,7 +257,7 @@ static void davinci_spi_chipselect(struct spi_device *spi, int value) * This function calculates the prescale value that generates a clock rate * less than or equal to the specified maximum. * - * Returns: calculated prescale - 1 for easy programming into SPI registers + * Returns: calculated prescale value for easy programming into SPI registers * or negative error number if valid prescalar cannot be updated. */ static inline int davinci_spi_get_prescale(struct davinci_spi *dspi, @@ -263,12 +265,13 @@ static inline int davinci_spi_get_prescale(struct davinci_spi *dspi, { int ret; - ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz); + /* Subtract 1 to match what will be programmed into SPI register. */ + ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz) - 1; - if (ret < 1 || ret > 256) + if (ret < dspi->prescaler_limit || ret > 255) return -EINVAL; - return ret - 1; + return ret; } /** @@ -832,13 +835,40 @@ rx_dma_failed: } #if defined(CONFIG_OF) + +/* OF SPI data structure */ +struct davinci_spi_of_data { + u8 version; + u8 prescaler_limit; +}; + +static const struct davinci_spi_of_data dm6441_spi_data = { + .version = SPI_VERSION_1, + .prescaler_limit = 2, +}; + +static const struct davinci_spi_of_data da830_spi_data = { + .version = SPI_VERSION_2, + .prescaler_limit = 2, +}; + +static const struct davinci_spi_of_data keystone_spi_data = { + .version = SPI_VERSION_1, + .prescaler_limit = 0, +}; + static const struct of_device_id davinci_spi_of_match[] = { { .compatible = "ti,dm6441-spi", + .data = &dm6441_spi_data, }, { .compatible = "ti,da830-spi", - .data = (void *)SPI_VERSION_2, + .data = &da830_spi_data, + }, + { + .compatible = "ti,keystone-spi", + .data = &keystone_spi_data, }, { }, }; @@ -857,21 +887,21 @@ static int spi_davinci_get_pdata(struct platform_device *pdev, struct davinci_spi *dspi) { struct device_node *node = pdev->dev.of_node; + struct davinci_spi_of_data *spi_data; struct davinci_spi_platform_data *pdata; unsigned int num_cs, intr_line = 0; const struct of_device_id *match; pdata = &dspi->pdata; - pdata->version = SPI_VERSION_1; match = of_match_device(davinci_spi_of_match, &pdev->dev); if (!match) return -ENODEV; - /* match data has the SPI version number for SPI_VERSION_2 */ - if (match->data == (void *)SPI_VERSION_2) - pdata->version = SPI_VERSION_2; + spi_data = (struct davinci_spi_of_data *)match->data; + pdata->version = spi_data->version; + pdata->prescaler_limit = spi_data->prescaler_limit; /* * default num_cs is 1 and all chipsel are internal to the chip * indicated by chip_sel being NULL or cs_gpios being NULL or @@ -991,7 +1021,7 @@ static int davinci_spi_probe(struct platform_device *pdev) dspi->bitbang.chipselect = davinci_spi_chipselect; dspi->bitbang.setup_transfer = davinci_spi_setup_transfer; - + dspi->prescaler_limit = pdata->prescaler_limit; dspi->version = pdata->version; dspi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP; |
