Many applications require more chip select lines than the board or processor allow. Introduce a mechanism to allow use of GPIO pins as chip select lines with the McSPI controller. To use this tionality, one simply provides a table mapping CS line numbers to GPIO numbers
omap2_mcspi_platform_config.cs_gpios. Signed-off-by: Ben Gamari <[email protected]> --- arch/arm/plat-omap/include/plat/mcspi.h | 1 + drivers/spi/omap2_mcspi.c | 19 +++++++++++++++++-- 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/arch/arm/plat-omap/include/plat/mcspi.h b/arch/arm/plat-omap/include/plat/mcspi.h index 3d51b18..c5670f2 100644 --- a/arch/arm/plat-omap/include/plat/mcspi.h +++ b/arch/arm/plat-omap/include/plat/mcspi.h @@ -10,6 +10,7 @@ struct omap2_mcspi_platform_config { unsigned short num_cs; unsigned int regs_offset; + int *cs_gpios; }; struct omap2_mcspi_dev_attr { diff --git a/drivers/spi/omap2_mcspi.c b/drivers/spi/omap2_mcspi.c index f41c906..20dec5d 100644 --- a/drivers/spi/omap2_mcspi.c +++ b/drivers/spi/omap2_mcspi.c @@ -36,6 +36,7 @@ #include <linux/pm_runtime.h> #include <linux/spi/spi.h> +#include <linux/gpio.h> #include <plat/dma.h> #include <plat/clock.h> @@ -121,6 +122,7 @@ struct omap2_mcspi { /* SPI1 has 4 channels, while SPI2 has 2 */ struct omap2_mcspi_dma *dma_channels; struct device *dev; + int *cs_gpios; }; struct omap2_mcspi_cs { @@ -227,7 +229,11 @@ static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active) { u32 l; + struct omap2_mcspi* mcspi = spi_master_get_devdata(spi->master); + if (mcspi->cs_gpios) + gpio_set_value(mcspi->cs_gpios[spi->chip_select], cs_active); + // TXS times out unless we force the CHCONF reg as well l = mcspi_cached_chconf0(spi); MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active); mcspi_write_chconf0(spi, l); @@ -1088,6 +1094,8 @@ static int __init omap2_mcspi_probe(struct platform_device *pdev) struct omap2_mcspi *mcspi; struct resource *r; int status = 0, i; + struct omap2_mcspi_platform_config* pconfig = pdev->dev.platform_data; + int num_dma; master = spi_alloc_master(&pdev->dev, sizeof *mcspi); if (master == NULL) { @@ -1110,6 +1118,13 @@ static int __init omap2_mcspi_probe(struct platform_device *pdev) mcspi = spi_master_get_devdata(master); mcspi->master = master; + if (pconfig && pconfig->cs_gpios) { + mcspi->cs_gpios = pconfig->cs_gpios; + num_dma = 1; + } else { + mcspi->cs_gpios = NULL; + num_dma = master->num_chipselect; + } r = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (r == NULL) { @@ -1139,14 +1154,14 @@ static int __init omap2_mcspi_probe(struct platform_device *pdev) INIT_LIST_HEAD(&mcspi->msg_queue); INIT_LIST_HEAD(&omap2_mcspi_ctx[master->bus_num - 1].cs); - mcspi->dma_channels = kcalloc(master->num_chipselect, + mcspi->dma_channels = kcalloc(num_dma, sizeof(struct omap2_mcspi_dma), GFP_KERNEL); if (mcspi->dma_channels == NULL) goto err2; - for (i = 0; i < master->num_chipselect; i++) { + for (i = 0; i < num_dma; i++) { char dma_ch_name[14]; struct resource *dma_res; -- 1.7.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
