Merge remote-tracking branch 'spi/topic/xilinx' into spi-next
This commit is contained in:
Mark Brown
commit
66886337bf
1 changed files with 163 additions and 135 deletions
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@ -22,6 +22,8 @@
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#include <linux/spi/xilinx_spi.h>
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#include <linux/io.h>
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#define XILINX_SPI_MAX_CS 32
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#define XILINX_SPI_NAME "xilinx_spi"
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/* Register definitions as per "OPB Serial Peripheral Interface (SPI) (v1.00e)
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@ -34,7 +36,8 @@
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#define XSPI_CR_MASTER_MODE 0x04
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#define XSPI_CR_CPOL 0x08
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#define XSPI_CR_CPHA 0x10
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#define XSPI_CR_MODE_MASK (XSPI_CR_CPHA | XSPI_CR_CPOL)
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#define XSPI_CR_MODE_MASK (XSPI_CR_CPHA | XSPI_CR_CPOL | \
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XSPI_CR_LSB_FIRST | XSPI_CR_LOOP)
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#define XSPI_CR_TXFIFO_RESET 0x20
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#define XSPI_CR_RXFIFO_RESET 0x40
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#define XSPI_CR_MANUAL_SSELECT 0x80
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@ -85,12 +88,11 @@ struct xilinx_spi {
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u8 *rx_ptr; /* pointer in the Tx buffer */
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const u8 *tx_ptr; /* pointer in the Rx buffer */
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int remaining_bytes; /* the number of bytes left to transfer */
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u8 bits_per_word;
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u8 bytes_per_word;
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int buffer_size; /* buffer size in words */
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u32 cs_inactive; /* Level of the CS pins when inactive*/
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unsigned int (*read_fn)(void __iomem *);
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void (*write_fn)(u32, void __iomem *);
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void (*tx_fn)(struct xilinx_spi *);
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void (*rx_fn)(struct xilinx_spi *);
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};
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static void xspi_write32(u32 val, void __iomem *addr)
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@ -113,49 +115,51 @@ static unsigned int xspi_read32_be(void __iomem *addr)
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return ioread32be(addr);
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}
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static void xspi_tx8(struct xilinx_spi *xspi)
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static void xilinx_spi_tx(struct xilinx_spi *xspi)
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{
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xspi->write_fn(*xspi->tx_ptr, xspi->regs + XSPI_TXD_OFFSET);
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xspi->tx_ptr++;
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}
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u32 data = 0;
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static void xspi_tx16(struct xilinx_spi *xspi)
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{
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xspi->write_fn(*(u16 *)(xspi->tx_ptr), xspi->regs + XSPI_TXD_OFFSET);
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xspi->tx_ptr += 2;
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}
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static void xspi_tx32(struct xilinx_spi *xspi)
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{
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xspi->write_fn(*(u32 *)(xspi->tx_ptr), xspi->regs + XSPI_TXD_OFFSET);
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xspi->tx_ptr += 4;
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}
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static void xspi_rx8(struct xilinx_spi *xspi)
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{
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u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
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if (xspi->rx_ptr) {
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*xspi->rx_ptr = data & 0xff;
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xspi->rx_ptr++;
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if (!xspi->tx_ptr) {
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xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET);
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return;
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}
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}
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static void xspi_rx16(struct xilinx_spi *xspi)
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{
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u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
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if (xspi->rx_ptr) {
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*(u16 *)(xspi->rx_ptr) = data & 0xffff;
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xspi->rx_ptr += 2;
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switch (xspi->bytes_per_word) {
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case 1:
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data = *(u8 *)(xspi->tx_ptr);
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break;
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case 2:
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data = *(u16 *)(xspi->tx_ptr);
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break;
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case 4:
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data = *(u32 *)(xspi->tx_ptr);
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break;
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}
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xspi->write_fn(data, xspi->regs + XSPI_TXD_OFFSET);
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xspi->tx_ptr += xspi->bytes_per_word;
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}
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static void xspi_rx32(struct xilinx_spi *xspi)
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static void xilinx_spi_rx(struct xilinx_spi *xspi)
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{
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u32 data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
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if (xspi->rx_ptr) {
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if (!xspi->rx_ptr)
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return;
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switch (xspi->bytes_per_word) {
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case 1:
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*(u8 *)(xspi->rx_ptr) = data;
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break;
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case 2:
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*(u16 *)(xspi->rx_ptr) = data;
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break;
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case 4:
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*(u32 *)(xspi->rx_ptr) = data;
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xspi->rx_ptr += 4;
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break;
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}
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xspi->rx_ptr += xspi->bytes_per_word;
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}
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static void xspi_init_hw(struct xilinx_spi *xspi)
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@ -165,46 +169,56 @@ static void xspi_init_hw(struct xilinx_spi *xspi)
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/* Reset the SPI device */
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xspi->write_fn(XIPIF_V123B_RESET_MASK,
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regs_base + XIPIF_V123B_RESETR_OFFSET);
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/* Disable all the interrupts just in case */
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xspi->write_fn(0, regs_base + XIPIF_V123B_IIER_OFFSET);
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/* Enable the global IPIF interrupt */
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xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,
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regs_base + XIPIF_V123B_DGIER_OFFSET);
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/* Enable the transmit empty interrupt, which we use to determine
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* progress on the transmission.
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*/
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xspi->write_fn(XSPI_INTR_TX_EMPTY,
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regs_base + XIPIF_V123B_IIER_OFFSET);
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/* Disable the global IPIF interrupt */
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xspi->write_fn(0, regs_base + XIPIF_V123B_DGIER_OFFSET);
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/* Deselect the slave on the SPI bus */
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xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET);
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/* Disable the transmitter, enable Manual Slave Select Assertion,
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* put SPI controller into master mode, and enable it */
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xspi->write_fn(XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT |
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XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET |
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XSPI_CR_RXFIFO_RESET, regs_base + XSPI_CR_OFFSET);
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xspi->write_fn(XSPI_CR_MANUAL_SSELECT | XSPI_CR_MASTER_MODE |
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XSPI_CR_ENABLE | XSPI_CR_TXFIFO_RESET | XSPI_CR_RXFIFO_RESET,
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regs_base + XSPI_CR_OFFSET);
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}
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static void xilinx_spi_chipselect(struct spi_device *spi, int is_on)
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{
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struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
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u16 cr;
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u32 cs;
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if (is_on == BITBANG_CS_INACTIVE) {
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/* Deselect the slave on the SPI bus */
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xspi->write_fn(0xffff, xspi->regs + XSPI_SSR_OFFSET);
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} else if (is_on == BITBANG_CS_ACTIVE) {
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/* Set the SPI clock phase and polarity */
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u16 cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET)
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& ~XSPI_CR_MODE_MASK;
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if (spi->mode & SPI_CPHA)
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cr |= XSPI_CR_CPHA;
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if (spi->mode & SPI_CPOL)
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cr |= XSPI_CR_CPOL;
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xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
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/* We do not check spi->max_speed_hz here as the SPI clock
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* frequency is not software programmable (the IP block design
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* parameter)
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*/
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/* Activate the chip select */
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xspi->write_fn(~(0x0001 << spi->chip_select),
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xspi->regs + XSPI_SSR_OFFSET);
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xspi->write_fn(xspi->cs_inactive, xspi->regs + XSPI_SSR_OFFSET);
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return;
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}
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/* Set the SPI clock phase and polarity */
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cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) & ~XSPI_CR_MODE_MASK;
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if (spi->mode & SPI_CPHA)
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cr |= XSPI_CR_CPHA;
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if (spi->mode & SPI_CPOL)
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cr |= XSPI_CR_CPOL;
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if (spi->mode & SPI_LSB_FIRST)
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cr |= XSPI_CR_LSB_FIRST;
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if (spi->mode & SPI_LOOP)
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cr |= XSPI_CR_LOOP;
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xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
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/* We do not check spi->max_speed_hz here as the SPI clock
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* frequency is not software programmable (the IP block design
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* parameter)
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*/
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cs = xspi->cs_inactive;
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cs ^= BIT(spi->chip_select);
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/* Activate the chip select */
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xspi->write_fn(cs, xspi->regs + XSPI_SSR_OFFSET);
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}
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/* spi_bitbang requires custom setup_transfer() to be defined if there is a
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@ -213,85 +227,85 @@ static void xilinx_spi_chipselect(struct spi_device *spi, int is_on)
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static int xilinx_spi_setup_transfer(struct spi_device *spi,
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struct spi_transfer *t)
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{
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struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
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if (spi->mode & SPI_CS_HIGH)
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xspi->cs_inactive &= ~BIT(spi->chip_select);
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else
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xspi->cs_inactive |= BIT(spi->chip_select);
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return 0;
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}
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static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi)
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{
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u8 sr;
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/* Fill the Tx FIFO with as many bytes as possible */
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sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
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while ((sr & XSPI_SR_TX_FULL_MASK) == 0 && xspi->remaining_bytes > 0) {
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if (xspi->tx_ptr)
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xspi->tx_fn(xspi);
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else
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xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET);
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xspi->remaining_bytes -= xspi->bits_per_word / 8;
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sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
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}
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}
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static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
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{
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struct xilinx_spi *xspi = spi_master_get_devdata(spi->master);
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u32 ipif_ier;
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int remaining_words; /* the number of words left to transfer */
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bool use_irq = false;
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u16 cr = 0;
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/* We get here with transmitter inhibited */
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xspi->tx_ptr = t->tx_buf;
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xspi->rx_ptr = t->rx_buf;
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xspi->remaining_bytes = t->len;
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remaining_words = t->len / xspi->bytes_per_word;
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reinit_completion(&xspi->done);
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if (xspi->irq >= 0 && remaining_words > xspi->buffer_size) {
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use_irq = true;
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xspi->write_fn(XSPI_INTR_TX_EMPTY,
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xspi->regs + XIPIF_V123B_IISR_OFFSET);
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/* Enable the global IPIF interrupt */
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xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,
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xspi->regs + XIPIF_V123B_DGIER_OFFSET);
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/* Inhibit irq to avoid spurious irqs on tx_empty*/
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cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET);
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xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
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xspi->regs + XSPI_CR_OFFSET);
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}
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/* Enable the transmit empty interrupt, which we use to determine
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* progress on the transmission.
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*/
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ipif_ier = xspi->read_fn(xspi->regs + XIPIF_V123B_IIER_OFFSET);
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xspi->write_fn(ipif_ier | XSPI_INTR_TX_EMPTY,
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xspi->regs + XIPIF_V123B_IIER_OFFSET);
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while (remaining_words) {
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int n_words, tx_words, rx_words;
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for (;;) {
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u16 cr;
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u8 sr;
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n_words = min(remaining_words, xspi->buffer_size);
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xilinx_spi_fill_tx_fifo(xspi);
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tx_words = n_words;
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while (tx_words--)
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xilinx_spi_tx(xspi);
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/* Start the transfer by not inhibiting the transmitter any
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* longer
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*/
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cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET) &
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~XSPI_CR_TRANS_INHIBIT;
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xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
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wait_for_completion(&xspi->done);
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if (use_irq) {
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xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
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wait_for_completion(&xspi->done);
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} else
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while (!(xspi->read_fn(xspi->regs + XSPI_SR_OFFSET) &
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XSPI_SR_TX_EMPTY_MASK))
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;
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/* A transmit has just completed. Process received data and
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* check for more data to transmit. Always inhibit the
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* transmitter while the Isr refills the transmit register/FIFO,
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* or make sure it is stopped if we're done.
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*/
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cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET);
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xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
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if (use_irq)
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xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
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xspi->regs + XSPI_CR_OFFSET);
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/* Read out all the data from the Rx FIFO */
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sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
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while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) {
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xspi->rx_fn(xspi);
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sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
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}
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rx_words = n_words;
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while (rx_words--)
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xilinx_spi_rx(xspi);
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|
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/* See if there is more data to send */
|
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if (xspi->remaining_bytes <= 0)
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break;
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remaining_words -= n_words;
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}
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|
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/* Disable the transmit empty interrupt */
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xspi->write_fn(ipif_ier, xspi->regs + XIPIF_V123B_IIER_OFFSET);
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if (use_irq)
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xspi->write_fn(0, xspi->regs + XIPIF_V123B_DGIER_OFFSET);
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|
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return t->len - xspi->remaining_bytes;
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return t->len;
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}
|
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|
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|
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|
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@ -316,6 +330,28 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id)
|
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return IRQ_HANDLED;
|
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}
|
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|
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static int xilinx_spi_find_buffer_size(struct xilinx_spi *xspi)
|
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{
|
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u8 sr;
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int n_words = 0;
|
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|
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/*
|
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* Before the buffer_size detection we reset the core
|
||||
* to make sure we start with a clean state.
|
||||
*/
|
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xspi->write_fn(XIPIF_V123B_RESET_MASK,
|
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xspi->regs + XIPIF_V123B_RESETR_OFFSET);
|
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|
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/* Fill the Tx FIFO with as many words as possible */
|
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do {
|
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xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET);
|
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sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
|
||||
n_words++;
|
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} while (!(sr & XSPI_SR_TX_FULL_MASK));
|
||||
|
||||
return n_words;
|
||||
}
|
||||
|
||||
static const struct of_device_id xilinx_spi_of_match[] = {
|
||||
{ .compatible = "xlnx,xps-spi-2.00.a", },
|
||||
{ .compatible = "xlnx,xps-spi-2.00.b", },
|
||||
|
|
@ -348,14 +384,21 @@ static int xilinx_spi_probe(struct platform_device *pdev)
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|||
return -EINVAL;
|
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}
|
||||
|
||||
if (num_cs > XILINX_SPI_MAX_CS) {
|
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dev_err(&pdev->dev, "Invalid number of spi slaves\n");
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
master = spi_alloc_master(&pdev->dev, sizeof(struct xilinx_spi));
|
||||
if (!master)
|
||||
return -ENODEV;
|
||||
|
||||
/* the spi->mode bits understood by this driver: */
|
||||
master->mode_bits = SPI_CPOL | SPI_CPHA;
|
||||
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_LOOP |
|
||||
SPI_CS_HIGH;
|
||||
|
||||
xspi = spi_master_get_devdata(master);
|
||||
xspi->cs_inactive = 0xffffffff;
|
||||
xspi->bitbang.master = master;
|
||||
xspi->bitbang.chipselect = xilinx_spi_chipselect;
|
||||
xspi->bitbang.setup_transfer = xilinx_spi_setup_transfer;
|
||||
|
|
@ -392,36 +435,21 @@ static int xilinx_spi_probe(struct platform_device *pdev)
|
|||
}
|
||||
|
||||
master->bits_per_word_mask = SPI_BPW_MASK(bits_per_word);
|
||||
xspi->bits_per_word = 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 {
|
||||
ret = -EINVAL;
|
||||
goto put_master;
|
||||
xspi->bytes_per_word = bits_per_word / 8;
|
||||
xspi->buffer_size = xilinx_spi_find_buffer_size(xspi);
|
||||
|
||||
xspi->irq = platform_get_irq(pdev, 0);
|
||||
if (xspi->irq >= 0) {
|
||||
/* Register for SPI Interrupt */
|
||||
ret = devm_request_irq(&pdev->dev, xspi->irq, xilinx_spi_irq, 0,
|
||||
dev_name(&pdev->dev), xspi);
|
||||
if (ret)
|
||||
goto put_master;
|
||||
}
|
||||
|
||||
/* SPI controller initializations */
|
||||
xspi_init_hw(xspi);
|
||||
|
||||
xspi->irq = platform_get_irq(pdev, 0);
|
||||
if (xspi->irq < 0) {
|
||||
ret = xspi->irq;
|
||||
goto put_master;
|
||||
}
|
||||
|
||||
/* Register for SPI Interrupt */
|
||||
ret = devm_request_irq(&pdev->dev, xspi->irq, xilinx_spi_irq, 0,
|
||||
dev_name(&pdev->dev), xspi);
|
||||
if (ret)
|
||||
goto put_master;
|
||||
|
||||
ret = spi_bitbang_start(&xspi->bitbang);
|
||||
if (ret) {
|
||||
dev_err(&pdev->dev, "spi_bitbang_start FAILED\n");
|
||||
|
|
|
|||
Loading…
Reference in a new issue