/* Register definitions as per "OPB Serial Peripheral Interface (SPI) (v1.00e)
* Product Specification", DS464
*/
-#define XSPI_CR_OFFSET 0x60 /* 16-bit Control Register */
+#define XSPI_CR_OFFSET 0x60 /* Control Register */
#define XSPI_CR_ENABLE 0x02
#define XSPI_CR_MASTER_MODE 0x04
#define XSPI_CR_RXFIFO_RESET 0x40
#define XSPI_CR_MANUAL_SSELECT 0x80
#define XSPI_CR_TRANS_INHIBIT 0x100
+#define XSPI_CR_LSB_FIRST 0x200
-#define XSPI_SR_OFFSET 0x64 /* 8-bit Status Register */
+#define XSPI_SR_OFFSET 0x64 /* Status Register */
#define XSPI_SR_RX_EMPTY_MASK 0x01 /* Receive FIFO is empty */
#define XSPI_SR_RX_FULL_MASK 0x02 /* Receive FIFO is full */
#define XSPI_SR_TX_FULL_MASK 0x08 /* Transmit FIFO is full */
#define XSPI_SR_MODE_FAULT_MASK 0x10 /* Mode fault error */
-#define XSPI_TXD_OFFSET 0x68 /* 8-bit Data Transmit Register */
-#define XSPI_RXD_OFFSET 0x6c /* 8-bit Data Receive Register */
+#define XSPI_TXD_OFFSET 0x68 /* Data Transmit Register */
+#define XSPI_RXD_OFFSET 0x6c /* Data Receive Register */
#define XSPI_SSR_OFFSET 0x70 /* 32-bit Slave Select Register */
#define XSPI_INTR_TX_UNDERRUN 0x08 /* TxFIFO was underrun */
#define XSPI_INTR_RX_FULL 0x10 /* RxFIFO is full */
#define XSPI_INTR_RX_OVERRUN 0x20 /* RxFIFO was overrun */
+#define XSPI_INTR_TX_HALF_EMPTY 0x40 /* TxFIFO is half empty */
#define XIPIF_V123B_RESETR_OFFSET 0x40 /* IPIF reset register */
#define XIPIF_V123B_RESET_MASK 0x0a /* the value to write */
u32 irq;
- u32 speed_hz; /* SCK has a fixed frequency of speed_hz Hz */
-
u8 *rx_ptr; /* pointer in the Tx buffer */
const u8 *tx_ptr; /* pointer in the Rx buffer */
int remaining_bytes; /* the number of bytes left to transfer */
+ u8 bits_per_word;
unsigned int (*read_fn) (void __iomem *);
void (*write_fn) (u32, void __iomem *);
+ void (*tx_fn) (struct xilinx_spi *);
+ void (*rx_fn) (struct xilinx_spi *);
};
+static void xspi_tx8(struct xilinx_spi *xspi)
+{
+ xspi->write_fn(*xspi->tx_ptr, xspi->regs + XSPI_TXD_OFFSET);
+ xspi->tx_ptr++;
+}
+
+static void xspi_tx16(struct xilinx_spi *xspi)
+{
+ xspi->write_fn(*(u16 *)(xspi->tx_ptr), xspi->regs + XSPI_TXD_OFFSET);
+ xspi->tx_ptr += 2;
+}
+
+static void xspi_tx32(struct xilinx_spi *xspi)
+{
+ xspi->write_fn(*(u32 *)(xspi->tx_ptr), xspi->regs + XSPI_TXD_OFFSET);
+ xspi->tx_ptr += 4;
+}
+
+static void xspi_rx8(struct xilinx_spi *xspi)
+{
+ u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
+ if (xspi->rx_ptr) {
+ *xspi->rx_ptr = data & 0xff;
+ xspi->rx_ptr++;
+ }
+}
+
+static void xspi_rx16(struct xilinx_spi *xspi)
+{
+ u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
+ if (xspi->rx_ptr) {
+ *(u16 *)(xspi->rx_ptr) = data & 0xffff;
+ xspi->rx_ptr += 2;
+ }
+}
+
+static void xspi_rx32(struct xilinx_spi *xspi)
+{
+ u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
+ if (xspi->rx_ptr) {
+ *(u32 *)(xspi->rx_ptr) = data;
+ xspi->rx_ptr += 4;
+ }
+}
+
static void xspi_init_hw(struct xilinx_spi *xspi)
{
void __iomem *regs_base = xspi->regs;
/* Disable the transmitter, enable Manual Slave Select Assertion,
* put SPI controller into master mode, and enable it */
xspi->write_fn(XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT |
- XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE,
- regs_base + XSPI_CR_OFFSET);
+ XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET |
+ XSPI_CR_RXFIFO_RESET, regs_base + XSPI_CR_OFFSET);
}
static void xilinx_spi_chipselect(struct spi_device *spi, int is_on)
/* spi_bitbang requires custom setup_transfer() to be defined if there is a
* custom txrx_bufs(). We have nothing to setup here as the SPI IP block
- * supports just 8 bits per word, and SPI clock can't be changed in software.
- * Check for 8 bits per word. Chip select delay calculations could be
+ * supports 8 or 16 bits per word which cannot be changed in software.
+ * SPI clock can't be changed in software either.
+ * Check for correct bits per word. Chip select delay calculations could be
* added here as soon as bitbang_work() can be made aware of the delay value.
*/
static int xilinx_spi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
+ struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
u8 bits_per_word;
bits_per_word = (t && t->bits_per_word)
? t->bits_per_word : spi->bits_per_word;
- if (bits_per_word != 8) {
+ if (bits_per_word != xspi->bits_per_word) {
dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
__func__, bits_per_word);
return -EINVAL;
static int xilinx_spi_setup(struct spi_device *spi)
{
- struct spi_bitbang *bitbang;
- struct xilinx_spi *xspi;
- int retval;
-
- xspi = spi_master_get_devdata(spi->master);
- bitbang = &xspi->bitbang;
-
- retval = xilinx_spi_setup_transfer(spi, NULL);
- if (retval < 0)
- return retval;
-
+ /* 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;
}
sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
while ((sr & XSPI_SR_TX_FULL_MASK) == 0 && xspi->remaining_bytes > 0) {
if (xspi->tx_ptr)
- xspi->write_fn(*xspi->tx_ptr++,
- xspi->regs + XSPI_TXD_OFFSET);
+ xspi->tx_fn(xspi);
else
xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET);
- xspi->remaining_bytes--;
+ xspi->remaining_bytes -= xspi->bits_per_word / 8;
sr = xspi->read_fn(xspi->regs + XSPI_SR_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) {
- u8 data;
-
- data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
- if (xspi->rx_ptr) {
- *xspi->rx_ptr++ = data;
- }
+ xspi->rx_fn(xspi);
sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
}
xspi->read_fn = ioread32be;
xspi->write_fn = iowrite32be;
}
+ xspi->bits_per_word = pdata->bits_per_word;
+ if (xspi->bits_per_word == 8) {
+ xspi->tx_fn = xspi_tx8;
+ xspi->rx_fn = xspi_rx8;
+ } else if (xspi->bits_per_word == 16) {
+ xspi->tx_fn = xspi_tx16;
+ xspi->rx_fn = xspi_rx16;
+ } else if (xspi->bits_per_word == 32) {
+ xspi->tx_fn = xspi_tx32;
+ xspi->rx_fn = xspi_rx32;
+ } else
+ goto unmap_io;
+
/* SPI controller initializations */
xspi_init_hw(xspi);
projects / platform / kernel / linux-rpi.git / commitdiff