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Diffstat (limited to 'drivers/spi/spi-xilinx.c')
-rw-r--r--drivers/spi/spi-xilinx.c120
1 files changed, 56 insertions, 64 deletions
diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c
index e1d769607425..fb56fcfdf65e 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;
@@ -267,7 +253,6 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
u32 ipif_ier;
- u16 cr;
/* We get here with transmitter inhibited */
@@ -276,7 +261,6 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
xspi->remaining_bytes = t->len;
INIT_COMPLETION(xspi->done);
- xilinx_spi_fill_tx_fifo(xspi);
/* Enable the transmit empty interrupt, which we use to determine
* progress on the transmission.
@@ -285,12 +269,41 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
xspi->write_fn(ipif_ier | XSPI_INTR_TX_EMPTY,
xspi->regs + XIPIF_V123B_IIER_OFFSET);
- /* Start the transfer by not inhibiting the transmitter any longer */
- cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) &
- ~XSPI_CR_TRANS_INHIBIT;
- xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
+ for (;;) {
+ u16 cr;
+ u8 sr;
+
+ xilinx_spi_fill_tx_fifo(xspi);
+
+ /* Start the transfer by not inhibiting the transmitter any
+ * longer
+ */
+ cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) &
+ ~XSPI_CR_TRANS_INHIBIT;
+ xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
- wait_for_completion(&xspi->done);
+ wait_for_completion(&xspi->done);
+
+ /* A transmit has just completed. Process received data and
+ * check for more data to transmit. Always inhibit the
+ * transmitter while the Isr refills the transmit register/FIFO,
+ * or make sure it is stopped if we're done.
+ */
+ cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET);
+ xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
+ xspi->regs + XSPI_CR_OFFSET);
+
+ /* Read out all the data from the Rx FIFO */
+ sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
+ while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) {
+ xspi->rx_fn(xspi);
+ sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
+ }
+
+ /* See if there is more data to send */
+ if (xspi->remaining_bytes <= 0)
+ break;
+ }
/* Disable the transmit empty interrupt */
xspi->write_fn(ipif_ier, xspi->regs + XIPIF_V123B_IIER_OFFSET);
@@ -314,38 +327,7 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id)
xspi->write_fn(ipif_isr, xspi->regs + XIPIF_V123B_IISR_OFFSET);
if (ipif_isr & XSPI_INTR_TX_EMPTY) { /* Transmission completed */
- u16 cr;
- u8 sr;
-
- /* A transmit has just completed. Process received data and
- * check for more data to transmit. Always inhibit the
- * transmitter while the Isr refills the transmit register/FIFO,
- * or make sure it is stopped if we're done.
- */
- cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET);
- xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
- xspi->regs + XSPI_CR_OFFSET);
-
- /* Read out all the data from the Rx FIFO */
- sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
- while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) {
- xspi->rx_fn(xspi);
- sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
- }
-
- /* See if there is more data to send */
- if (xspi->remaining_bytes > 0) {
- xilinx_spi_fill_tx_fifo(xspi);
- /* Start the transfer by not inhibiting the
- * transmitter any longer
- */
- xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
- } else {
- /* No more data to send.
- * Indicate the transfer is completed.
- */
- complete(&xspi->done);
- }
+ complete(&xspi->done);
}
return IRQ_HANDLED;
@@ -359,11 +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)
@@ -377,7 +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),
@@ -396,13 +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;
@@ -466,14 +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;
}
@@ -505,7 +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;
@@ -521,7 +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;
}
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