diff options
Diffstat (limited to 'drivers/spi/spi-xilinx.c')
| -rw-r--r-- | drivers/spi/spi-xilinx.c | 48 |
1 files changed, 22 insertions, 26 deletions
diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c index 34d18dcfa0d..fb56fcfdf65 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 @@ -232,21 +233,6 @@ static int xilinx_spi_setup_transfer(struct spi_device *spi, return 0; } -static int xilinx_spi_setup(struct spi_device *spi) -{ - /* always return 0, we can not check the number of bits. - * There are cases when SPI setup is called before any driver is - * there, in that case the SPI core defaults to 8 bits, which we - * do not support in some cases. But if we return an error, the - * SPI device would not be registered and no driver can get hold of it - * When the driver is there, it will call SPI setup again with the - * correct number of bits per transfer. - * If a driver setups with the wrong bit number, it will fail when - * it tries to do a transfer - */ - return 0; -} - static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi) { u8 sr; @@ -315,7 +301,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) } /* See if there is more data to send */ - if (!xspi->remaining_bytes > 0) + if (xspi->remaining_bytes <= 0) break; } @@ -355,11 +341,12 @@ 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) @@ -373,7 +360,6 @@ struct spi_master *xilinx_spi_init(struct device *dev, struct resource *mem, xspi->bitbang.chipselect = xilinx_spi_chipselect; xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer; xspi->bitbang.txrx_bufs = xilinx_spi_txrx_bufs; - xspi->bitbang.master->setup = xilinx_spi_setup; init_completion(&xspi->done); if (!request_mem_region(mem->start, resource_size(mem), @@ -392,13 +378,25 @@ 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; @@ -462,14 +460,13 @@ 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; } @@ -501,7 +498,7 @@ 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; @@ -517,7 +514,6 @@ static int xilinx_spi_probe(struct platform_device *dev) static int xilinx_spi_remove(struct platform_device *dev) { xilinx_spi_deinit(platform_get_drvdata(dev)); - platform_set_drvdata(dev, 0); return 0; } |