From fa466c91970a0207d9384016cc7884a7f61834b6 Mon Sep 17 00:00:00 2001 From: Franklin S Cooper Jr Date: Wed, 22 Jul 2015 07:32:22 -0500 Subject: [PATCH] spi: davinci: Choose correct pre-scaler limit based on SOC Currently the pre-scaler limit is incorrect. The value differs slightly for various devices so a single value can't be used. Using the compatible field select the correct pre-scaler limit. Add new compatible field value for Keystone devices to support their unique pre-scaler limit value. Signed-off-by: Franklin S Cooper Jr Reviewed-by: Sekhar Nori Signed-off-by: Mark Brown --- .../devicetree/bindings/spi/spi-davinci.txt | 2 + drivers/spi/spi-davinci.c | 43 ++++++++++++++++--- include/linux/platform_data/spi-davinci.h | 1 + 3 files changed, 39 insertions(+), 7 deletions(-) diff --git a/Documentation/devicetree/bindings/spi/spi-davinci.txt b/Documentation/devicetree/bindings/spi/spi-davinci.txt index 12ecfe9e3599..d1e914adcf6e 100644 --- a/Documentation/devicetree/bindings/spi/spi-davinci.txt +++ b/Documentation/devicetree/bindings/spi/spi-davinci.txt @@ -12,6 +12,8 @@ Required properties: - compatible: - "ti,dm6441-spi" for SPI used similar to that on DM644x SoC family - "ti,da830-spi" for SPI used similar to that on DA8xx SoC family + - "ti,keystone-spi" for SPI used similar to that on Keystone2 SoC + family - reg: Offset and length of SPI controller register space - num-cs: Number of chip selects. This includes internal as well as GPIO chip selects. diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c index b4605c4158f4..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; @@ -266,7 +268,7 @@ static inline int davinci_spi_get_prescale(struct davinci_spi *dspi, /* 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 < 0 || ret > 255) + if (ret < dspi->prescaler_limit || ret > 255) return -EINVAL; return ret; @@ -833,13 +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, }, { }, }; @@ -858,21 +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 @@ -992,7 +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; diff --git a/include/linux/platform_data/spi-davinci.h b/include/linux/platform_data/spi-davinci.h index 8dc2fa47a2aa..f4edcb03c40c 100644 --- a/include/linux/platform_data/spi-davinci.h +++ b/include/linux/platform_data/spi-davinci.h @@ -49,6 +49,7 @@ struct davinci_spi_platform_data { u8 num_chipselect; u8 intr_line; u8 *chip_sel; + u8 prescaler_limit; bool cshold_bug; enum dma_event_q dma_event_q; }; -- 2.20.1