spi: spi-xilinx: Add run run-time endian detection
Do not load endian value from platform data
and rather autodetect it.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c
index e1d7696..bb6ae4e 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
@@ -359,11 +360,12 @@
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)
@@ -396,13 +398,25 @@
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;
@@ -466,14 +480,13 @@
{
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;
}
@@ -505,7 +518,7 @@
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;