Messages in this thread Patch in this message | | | From | Michal Simek <> | Subject | [PATCH 3/3] spi: spi-xilinx: Add run run-time endian detection | Date | Tue, 4 Jun 2013 16:02:36 +0200 |
| |
Do not load endian value from platform data and rather autodetect it.
Signed-off-by: Michal Simek <michal.simek@xilinx.com> --- drivers/mfd/timberdale.c | 1 - drivers/spi/spi-xilinx.c | 29 +++++++++++++++++++++-------- include/linux/spi/xilinx_spi.h | 1 - 3 files changed, 21 insertions(+), 10 deletions(-)
diff --git a/drivers/mfd/timberdale.c b/drivers/mfd/timberdale.c index 59e0ee2..0c1fcbc 100644 --- a/drivers/mfd/timberdale.c +++ b/drivers/mfd/timberdale.c @@ -145,7 +145,6 @@ static struct spi_board_info timberdale_spi_8bit_board_info[] = {
static struct xspi_platform_data timberdale_xspi_platform_data = { .num_chipselect = 3, - .little_endian = true, /* bits per word and devices will be filled in runtime depending * on the HW config */ diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index d690756..0b7b8d7 100644 --- a/drivers/spi/spi-xilinx.c +++ b/drivers/spi/spi-xilinx.c @@ -30,6 +30,7 @@ */ #define XSPI_CR_OFFSET 0x60 /* Control Register */
+#define XSPI_CR_LOOP 0x01 #define XSPI_CR_ENABLE 0x02 #define XSPI_CR_MASTER_MODE 0x04 #define XSPI_CR_CPOL 0x08 @@ -355,11 +356,12 @@ static const struct of_device_id xilinx_spi_of_match[] = { MODULE_DEVICE_TABLE(of, xilinx_spi_of_match);
struct spi_master *xilinx_spi_init(struct device *dev, struct resource *mem, - u32 irq, s16 bus_num, int num_cs, int little_endian, int bits_per_word) + u32 irq, s16 bus_num, int num_cs, int bits_per_word) { struct spi_master *master; struct xilinx_spi *xspi; int ret; + u32 tmp;
master = spi_alloc_master(dev, sizeof(struct xilinx_spi)); if (!master) @@ -395,13 +397,25 @@ struct spi_master *xilinx_spi_init(struct device *dev, struct resource *mem,
xspi->mem = *mem; xspi->irq = irq; - if (little_endian) { - xspi->read_fn = xspi_read32; - xspi->write_fn = xspi_write32; - } else { + + /* + * Detect endianess on the IP via loop bit in CR. Detection + * must be done before reset is sent because incorrect reset + * value generates error interrupt. + * Setup little endian helper functions first and try to use them + * and check if bit was correctly setup or not. + */ + xspi->read_fn = xspi_read32; + xspi->write_fn = xspi_write32; + + xspi->write_fn(XSPI_CR_LOOP, xspi->regs + XSPI_CR_OFFSET); + tmp = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET); + tmp &= XSPI_CR_LOOP; + if (tmp != XSPI_CR_LOOP) { xspi->read_fn = xspi_read32_be; xspi->write_fn = xspi_write32_be; } + xspi->bits_per_word = bits_per_word; if (xspi->bits_per_word == 8) { xspi->tx_fn = xspi_tx8; @@ -465,14 +479,13 @@ static int xilinx_spi_probe(struct platform_device *dev) { struct xspi_platform_data *pdata; struct resource *r; - int irq, num_cs = 0, little_endian = 0, bits_per_word = 8; + int irq, num_cs = 0, bits_per_word = 8; struct spi_master *master; u8 i;
pdata = dev->dev.platform_data; if (pdata) { num_cs = pdata->num_chipselect; - little_endian = pdata->little_endian; bits_per_word = pdata->bits_per_word; }
@@ -504,7 +517,7 @@ static int xilinx_spi_probe(struct platform_device *dev) return -ENXIO;
master = xilinx_spi_init(&dev->dev, r, irq, dev->id, num_cs, - little_endian, bits_per_word); + bits_per_word); if (!master) return -ENODEV;
diff --git a/include/linux/spi/xilinx_spi.h b/include/linux/spi/xilinx_spi.h index 6f17278..333ecdf 100644 --- a/include/linux/spi/xilinx_spi.h +++ b/include/linux/spi/xilinx_spi.h @@ -11,7 +11,6 @@ */ struct xspi_platform_data { u16 num_chipselect; - bool little_endian; u8 bits_per_word; struct spi_board_info *devices; u8 num_devices; -- 1.8.2.3 [unhandled content-type:application/pgp-signature] | |