Re: [LINUX RFC V2 2/2] spi: Add support for Zynq Ultrascale+ MPSoC GQSPI controller

[Shubhrajyoti Datta <omaplinuxkernel@xxxxxxxxx>]

hi,

Some minor comments.


On Fri, Jun 5, 2015 at 6:37 PM, Ranjit Waghmode
<ranjit.waghmode@xxxxxxxxxx> wrote:
> This patch adds support for GQSPI controller driver used by
> Zynq Ultrascale+ MPSoC
>
> Signed-off-by: Ranjit Waghmode <ranjit.waghmode@xxxxxxxxxx>
> ---
> Here is the v2 series.
<snip
>
> + */
> +static void zynqmp_qspi_chipselect(struct spi_device *qspi, bool is_high)
> +{
> +       struct zynqmp_qspi *xqspi = spi_master_get_devdata(qspi->master);
> +       u32 genfifoentry = 0x0, statusreg, timeout;
> +
> +       genfifoentry |= GQSPI_GENFIFO_MODE_SPI;
> +       genfifoentry |= xqspi->genfifobus;
> +
> +       if (!is_high) {
> +               genfifoentry |= xqspi->genfifocs;
> +               genfifoentry |= GQSPI_GENFIFO_CS_SETUP;
> +       } else {
> +               genfifoentry |= GQSPI_GENFIFO_CS_HOLD;
> +       }
> +
> +       zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
> +
> +       /* Dummy generic FIFO entry */
> +       zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
> +
> +       /* Manually start the generic FIFO command */
> +       zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
> +                       zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
> +                       GQSPI_CFG_START_GEN_FIFO_MASK);
> +       timeout = 10000;
> +       /* Wait until the generic FIFO command is empty */
> +       do {
> +               statusreg = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);
> +               timeout--;

Can this be not busy.

> +       } while (!(statusreg &
> +                  GQSPI_ISR_GENFIFOEMPTY_MASK) &&
> +                (statusreg & GQSPI_ISR_TXEMPTY_MASK) && timeout);
> +       if (!timeout)
> +               dev_err(xqspi->dev, "Chip select timed out\n");
> +}
> +
> +/**
> + * zynqmp_qspi_setup_transfer: Configure QSPI controller for specified
> + *                             transfer
> + * @qspi:      Pointer to the spi_device structure
> + * @transfer:  Pointer to the spi_transfer structure which provides
> + *             information about next transfer setup parameters
> + *
> + * Sets the operational mode of QSPI controller for the next QSPI transfer and
> + * sets the requested clock frequency.
> + *
> + * Return:     Always 0
> + *
> + * Note:
> + *     If the requested frequency is not an exact match with what can be
> + *     obtained using the pre-scalar value, the driver sets the clock
> + *     frequency which is lower than the requested frequency (maximum lower)
> + *     for the transfer.
> + *
> + *     If the requested frequency is higher or lower than that is supported
> + *     by the QSPI controller the driver will set the highest or lowest
> + *     frequency supported by controller.
> + */
> +static int zynqmp_qspi_setup_transfer(struct spi_device *qspi,
> +                                     struct spi_transfer *transfer)
> +{
> +       struct zynqmp_qspi *xqspi = spi_master_get_devdata(qspi->master);
> +       ulong clk_rate;
> +       u32 config_reg, req_hz, baud_rate_val = 0;
> +
> +       if (transfer)
> +               req_hz = transfer->speed_hz;
> +       else
> +               req_hz = qspi->max_speed_hz;
> +
> +       /* Set the clock frequency */
> +       /* If req_hz == 0, default to lowest speed */
> +       clk_rate = clk_get_rate(xqspi->refclk);
> +
> +       while ((baud_rate_val < GQSPI_BAUD_DIV_MAX) &&
> +              (clk_rate /
> +               (GQSPI_BAUD_DIV_SHIFT << baud_rate_val)) > req_hz)
> +               baud_rate_val++;
> +
> +       config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
> +
> +       /* Set the QSPI clock phase and clock polarity */
> +       config_reg &= (~GQSPI_CFG_CLK_PHA_MASK) & (~GQSPI_CFG_CLK_POL_MASK);
> +
> +       if (qspi->mode & SPI_CPHA)
> +               config_reg |= GQSPI_CFG_CLK_PHA_MASK;
> +       if (qspi->mode & SPI_CPOL)
> +               config_reg |= GQSPI_CFG_CLK_POL_MASK;
> +
> +       config_reg &= ~GQSPI_CFG_BAUD_RATE_DIV_MASK;
> +       config_reg |= (baud_rate_val << GQSPI_CFG_BAUD_RATE_DIV_SHIFT);
> +       zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
> +       return 0;
> +}
> +
> +/**
> + * zynqmp_qspi_setup:  Configure the QSPI controller
> + * @qspi:      Pointer to the spi_device structure
> + *
> + * Sets the operational mode of QSPI controller for the next QSPI transfer,
> + * baud rate and divisor value to setup the requested qspi clock.
> + *
> + * Return:     0 Always

doesnt seem to be true

> + */
> +static int zynqmp_qspi_setup(struct spi_device *qspi)
> +{
> +       if (qspi->master->busy)
> +               return -EBUSY;
> +       return 0;
> +}
> +
> +/**
> + * zynqmp_qspi_filltxfifo:     Fills the TX FIFO as long as there is room in
> + *                             the FIFO or the bytes required to be
> + *                             transmitted.
> + * @xqspi:     Pointer to the zynqmp_qspi structure
> + * @size:      Number of bytes to be copied from TX buffer to TX FIFO
> + */
> +static void zynqmp_qspi_filltxfifo(struct zynqmp_qspi *xqspi, int size)
> +{
> +       u32 count = 0, intermediate;
> +
> +       while ((xqspi->bytes_to_transfer > 0) && (count < size)) {
> +               memcpy(&intermediate, xqspi->txbuf, 4);
> +               zynqmp_gqspi_write(xqspi, GQSPI_TXD_OFST, intermediate);
> +
> +               if (xqspi->bytes_to_transfer >= 4) {
> +                       xqspi->txbuf += 4;
> +                       xqspi->bytes_to_transfer -= 4;
> +               } else {
> +                       xqspi->txbuf += xqspi->bytes_to_transfer;
> +                       xqspi->bytes_to_transfer = 0;
> +               }
> +               count++;
> +       }
> +}
> +
> +/**
> + * zynqmp_qspi_readrxfifo:     Fills the RX FIFO as long as there is room in
> + *                             the FIFO.
> + * @xqspi:     Pointer to the zynqmp_qspi structure
> + * @size:      Number of bytes to be copied from RX buffer to RX FIFO
> + */
> +static void zynqmp_qspi_readrxfifo(struct zynqmp_qspi *xqspi, u32 size)
> +{
> +       ulong data;
> +       int count = 0;
> +
> +       while ((count < size) && (xqspi->bytes_to_receive > 0)) {
> +               if (xqspi->bytes_to_receive >= 4) {
> +                       (*(u32 *) xqspi->rxbuf) =
> +                       zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
> +                       xqspi->rxbuf += 4;
> +                       xqspi->bytes_to_receive -= 4;
> +                       count += 4;
> +               } else {
> +                       data = zynqmp_gqspi_read(xqspi, GQSPI_RXD_OFST);
> +                       count += xqspi->bytes_to_receive;
> +                       zynqmp_qspi_copy_read_data(xqspi, data,
> +                                                  xqspi->bytes_to_receive);
> +                       xqspi->bytes_to_receive = 0;
> +               }
> +       }
> +}
> +
> +/**
> + * zynqmp_process_dma_irq:     Handler for DMA done interrupt of QSPI
> + *                             controller
> + * @xqspi:     zynqmp_qspi instance pointer
> + *
> + * This function handles DMA interrupt only.
> + */
> +static void zynqmp_process_dma_irq(struct zynqmp_qspi *xqspi)
> +{
> +       u32 config_reg, genfifoentry;
> +
> +       dma_unmap_single(xqspi->dev, xqspi->dma_addr,
> +                               xqspi->dma_rx_bytes, DMA_FROM_DEVICE);
> +       xqspi->rxbuf += xqspi->dma_rx_bytes;
> +       xqspi->bytes_to_receive -= xqspi->dma_rx_bytes;
> +       xqspi->dma_rx_bytes = 0;
> +
> +       /* Disabling the DMA interrupts */
why?

> +       zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_DIS_OFST,
> +                                       GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);
> +
> +       if (xqspi->bytes_to_receive > 0) {
> +               /* Switch to IO mode,for remaining bytes to receive */
> +               config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
> +               config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
> +               zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
> +
> +               /* Initiate the transfer of remaining bytes */
> +               genfifoentry = xqspi->genfifoentry;
> +               genfifoentry |= xqspi->bytes_to_receive;
> +               zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
> +
> +               /* Dummy generic FIFO entry */
> +               zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
> +
> +               /* Manual start */
> +               zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
> +                       (zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
> +                       GQSPI_CFG_START_GEN_FIFO_MASK));
> +
> +               /* Enable the RX interrupts for IO mode */
> +               zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
> +                               GQSPI_IER_GENFIFOEMPTY_MASK |
> +                               GQSPI_IER_RXNEMPTY_MASK |
> +                               GQSPI_IER_RXEMPTY_MASK);
> +       }
> +}
> +
> +/**
> + * zynqmp_qspi_irq:    Interrupt service routine of the QSPI controller
> + * @irq:       IRQ number
> + * @dev_id:    Pointer to the xqspi structure
> + *
> + * This function handles TX empty only.
> + * On TX empty interrupt this function reads the received data from RX FIFO
> + * and fills the TX FIFO if there is any data remaining to be transferred.
> + *
> + * Return:     IRQ_HANDLED when interrupt is handled
> + *             IRQ_NONE otherwise.
> + */
> +static irqreturn_t zynqmp_qspi_irq(int irq, void *dev_id)
> +{
> +       struct spi_master *master = dev_id;
> +       struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
> +       int ret = IRQ_NONE;
> +       u32 status, mask, dma_status = 0;
> +
> +       status = zynqmp_gqspi_read(xqspi, GQSPI_ISR_OFST);
> +       zynqmp_gqspi_write(xqspi, GQSPI_ISR_OFST, status);
> +       mask = (status & ~(zynqmp_gqspi_read(xqspi, GQSPI_IMASK_OFST)));
> +
> +       /* Read and clear DMA status */
> +       if (xqspi->mode == GQSPI_MODE_DMA) {
> +               dma_status =
> +                       zynqmp_gqspi_read(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST);
> +               zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_I_STS_OFST,
> +                                                               dma_status);
> +       }
> +
> +       if (mask & GQSPI_ISR_TXNOT_FULL_MASK) {
> +               zynqmp_qspi_filltxfifo(xqspi, GQSPI_TX_FIFO_FILL);
> +               ret = IRQ_HANDLED;
> +       }
> +
> +       if (dma_status & GQSPI_QSPIDMA_DST_I_STS_DONE_MASK) {
> +               zynqmp_process_dma_irq(xqspi);
> +               ret = IRQ_HANDLED;
> +       } else if (!(mask & GQSPI_IER_RXEMPTY_MASK) &&
> +                       (mask & GQSPI_IER_GENFIFOEMPTY_MASK)) {
> +               zynqmp_qspi_readrxfifo(xqspi, GQSPI_RX_FIFO_FILL);
> +               ret = IRQ_HANDLED;
> +       }
> +
> +       if ((xqspi->bytes_to_receive == 0) && (xqspi->bytes_to_transfer == 0)
> +                       && ((status & GQSPI_IRQ_MASK) == GQSPI_IRQ_MASK)) {
> +               zynqmp_gqspi_write(xqspi, GQSPI_IDR_OFST, GQSPI_ISR_IDR_MASK);
> +               spi_finalize_current_transfer(master);
> +               ret = IRQ_HANDLED;
> +       }
> +       return ret;
> +}
> +
> +/**
> + * zynqmp_qspi_selectspimode:  Selects SPI mode - x1 or x2 or x4.
> + * @xqspi:     xqspi is a pointer to the GQSPI instance
> + * @spimode:   spimode - SPI or DUAL or QUAD.
> + * Return:     Mask to set desired SPI mode in GENFIFO entry.
> + */
> +static inline u32 zynqmp_qspi_selectspimode(struct zynqmp_qspi *xqspi,
> +                                               u8 spimode)
> +{
> +       u32 mask = 0;
> +
> +       switch (spimode) {
> +       case GQSPI_SELECT_MODE_DUALSPI:
> +               mask = GQSPI_GENFIFO_MODE_DUALSPI;
> +               break;
> +       case GQSPI_SELECT_MODE_QUADSPI:
> +               mask = GQSPI_GENFIFO_MODE_QUADSPI;
> +               break;
> +       case GQSPI_SELECT_MODE_SPI:
> +               mask = GQSPI_GENFIFO_MODE_SPI;
> +               break;
> +       default:
> +               dev_warn(xqspi->dev, "Invalid SPI mode\n");
> +       }
> +
> +       return mask;
> +}
> +
> +/**
> + * zynq_qspi_setuprxdma:       This function sets up the RX DMA operation
> + * @xqspi:     xqspi is a pointer to the GQSPI instance.
> + */
> +static void zynq_qspi_setuprxdma(struct zynqmp_qspi *xqspi)
> +{
> +       u32 rx_bytes, rx_rem, config_reg;
> +       dma_addr_t addr;
> +       u64 dma_align =  (u64)(uintptr_t)xqspi->rxbuf;
> +
> +       if ((xqspi->bytes_to_receive < 8) ||
> +               ((dma_align & GQSPI_DMA_UNALIGN) != 0x0)) {
> +               /* Setting to IO mode */
> +               config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
> +               config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
> +               zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
> +               xqspi->mode = GQSPI_MODE_IO;
> +               xqspi->dma_rx_bytes = 0;
> +               return;
> +       }
> +
> +       rx_rem = xqspi->bytes_to_receive % 4;
> +       rx_bytes = (xqspi->bytes_to_receive - rx_rem);
> +
> +       addr = dma_map_single(xqspi->dev, (void *)xqspi->rxbuf,
> +                                               rx_bytes, DMA_FROM_DEVICE);
> +       if (dma_mapping_error(xqspi->dev, addr))
> +               dev_err(xqspi->dev, "ERR:rxdma:memory not mapped\n");
> +
> +       xqspi->dma_rx_bytes = rx_bytes;
> +       xqspi->dma_addr = addr;
> +       zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_OFST,
> +                               (u32)(addr & 0xffffffff));
> +       addr = ((addr >> 16) >> 16);
> +       zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_ADDR_MSB_OFST,
> +                               ((u32)addr) & 0xfff);
> +
> +       /* Enabling the DMA mode */
> +       config_reg = zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST);
> +       config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
> +       config_reg |= GQSPI_CFG_MODE_EN_DMA_MASK;
> +       zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST, config_reg);
> +
> +       /* Switch to DMA mode */
> +       xqspi->mode = GQSPI_MODE_DMA;
> +
> +       /* Write the number of bytes to transfer */
> +       zynqmp_gqspi_write(xqspi, GQSPI_QSPIDMA_DST_SIZE_OFST, rx_bytes);
> +}
> +
> +/**
> + * zynqmp_qspi_txrxsetup:      This function checks the TX/RX buffers in
> + *                             the transfer and sets up the GENFIFO entries,
> + *                             TX FIFO as required.
> + * @xqspi:     xqspi is a pointer to the GQSPI instance.
> + * @transfer:  It is a pointer to the structure containing transfer data.
> + * @genfifoentry:      genfifoentry is pointer to the variable in which
> + *                     GENFIFO mask is returned to calling function
> + */
> +static void zynqmp_qspi_txrxsetup(struct zynqmp_qspi *xqspi,
> +                                 struct spi_transfer *transfer,
> +                                 u32 *genfifoentry)
> +{
> +       u32 config_reg;
> +
> +       /* Transmit */
> +       if ((xqspi->txbuf != NULL) && (xqspi->rxbuf == NULL)) {
> +               /* Setup data to be TXed */
> +               *genfifoentry &= ~GQSPI_GENFIFO_RX;
> +               *genfifoentry |= GQSPI_GENFIFO_DATA_XFER;
> +               *genfifoentry |= GQSPI_GENFIFO_TX;
> +               *genfifoentry |=
> +                       zynqmp_qspi_selectspimode(xqspi, transfer->tx_nbits);
> +               xqspi->bytes_to_transfer = transfer->len;
> +               if (xqspi->mode == GQSPI_MODE_DMA) {
> +                       config_reg = zynqmp_gqspi_read(xqspi,
> +                                                       GQSPI_CONFIG_OFST);
> +                       config_reg &= ~GQSPI_CFG_MODE_EN_MASK;
> +                       zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
> +                                                               config_reg);
> +                       xqspi->mode = GQSPI_MODE_IO;
> +               }
> +               zynqmp_qspi_filltxfifo(xqspi, GQSPI_TXD_DEPTH);
> +               /* Discard RX data */
> +               xqspi->bytes_to_receive = 0;
> +       } else if ((xqspi->txbuf == NULL) && (xqspi->rxbuf != NULL)) {
> +               /* Receive */
> +
> +               /* TX auto fill */
> +               *genfifoentry &= ~GQSPI_GENFIFO_TX;
> +               /* Setup RX */
> +               *genfifoentry |= GQSPI_GENFIFO_DATA_XFER;
> +               *genfifoentry |= GQSPI_GENFIFO_RX;
> +               *genfifoentry |=
> +                       zynqmp_qspi_selectspimode(xqspi, transfer->rx_nbits);
> +               xqspi->bytes_to_transfer = 0;
> +               xqspi->bytes_to_receive = transfer->len;
> +               zynq_qspi_setuprxdma(xqspi);
> +       }

Not a comment rather a query what happens in case of both rx and tx.


> +}
> +
> +/**
> + * zynqmp_qspi_start_transfer: Initiates the QSPI transfer
> + * @master:    Pointer to the spi_master structure which provides
> + *             information about the controller.
> + * @qspi:      Pointer to the spi_device structure
> + * @transfer:  Pointer to the spi_transfer structure which provide information
> + *             about next transfer parameters
> + *
> + * This function fills the TX FIFO, starts the QSPI transfer, and waits for the
> + * transfer to be completed.
> + *
> + * Return:     Number of bytes transferred in the last transfer
> + */
> +static int zynqmp_qspi_start_transfer(struct spi_master *master,
> +                                     struct spi_device *qspi,
> +                                     struct spi_transfer *transfer)
> +{
> +       struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
> +       u32 genfifoentry = 0x0, transfer_len;
> +
> +       xqspi->txbuf = transfer->tx_buf;
> +       xqspi->rxbuf = transfer->rx_buf;
> +
> +       zynqmp_qspi_setup_transfer(qspi, transfer);
> +
> +       genfifoentry |= xqspi->genfifocs;
> +       genfifoentry |= xqspi->genfifobus;
> +
> +       zynqmp_qspi_txrxsetup(xqspi, transfer, &genfifoentry);
> +
> +       if (xqspi->mode == GQSPI_MODE_DMA)
> +               transfer_len = xqspi->dma_rx_bytes;
> +       else
> +               transfer_len = transfer->len;
> +
> +       xqspi->genfifoentry = genfifoentry;
> +       if ((transfer_len) < GQSPI_GENFIFO_IMM_DATA_MASK) {
> +               genfifoentry &= ~GQSPI_GENFIFO_IMM_DATA_MASK;
> +               genfifoentry |= transfer_len;
> +               zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, genfifoentry);
> +       } else {
> +               int tempcount = transfer_len;
> +               u32 exponent = 8;       /* 2^8 = 256 */
> +               u8 imm_data = tempcount & 0xFF;
> +
> +               tempcount &= ~(tempcount & 0xFF);
> +               /* Immediate entry */
> +               if (tempcount != 0) {
> +                       /* Exponent entries */
> +                       genfifoentry |= GQSPI_GENFIFO_EXP;
> +                       while (tempcount != 0) {
> +                               if (tempcount & GQSPI_GENFIFO_EXP_START) {
> +                                       genfifoentry &=
> +                                           ~GQSPI_GENFIFO_IMM_DATA_MASK;
> +                                       genfifoentry |= exponent;
> +                                       zynqmp_gqspi_write(xqspi,
> +                                                          GQSPI_GEN_FIFO_OFST,
> +                                                          genfifoentry);
> +                               }
> +                               tempcount = tempcount >> 1;
> +                               exponent++;
> +                       }
> +               }
> +               if (imm_data != 0) {
> +                       genfifoentry &= ~GQSPI_GENFIFO_EXP;
> +                       genfifoentry &= ~GQSPI_GENFIFO_IMM_DATA_MASK;
> +                       genfifoentry |= (u8) (imm_data & 0xFF);
> +                       zynqmp_gqspi_write(xqspi,
> +                                          GQSPI_GEN_FIFO_OFST, genfifoentry);
> +               }
> +       }
> +
> +       if ((xqspi->mode == GQSPI_MODE_IO) &&
> +                       (xqspi->rxbuf != NULL)) {
> +               /* Dummy generic FIFO entry */
> +               zynqmp_gqspi_write(xqspi, GQSPI_GEN_FIFO_OFST, 0x0);
> +       }
> +
> +       /* Since we are using manual mode */
> +       zynqmp_gqspi_write(xqspi, GQSPI_CONFIG_OFST,
> +                          zynqmp_gqspi_read(xqspi, GQSPI_CONFIG_OFST) |
> +                          GQSPI_CFG_START_GEN_FIFO_MASK);
> +
> +       if (xqspi->txbuf != NULL)
> +               /* Enable interrupts for TX */
> +               zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
> +                                  GQSPI_IER_TXEMPTY_MASK |
> +                                       GQSPI_IER_GENFIFOEMPTY_MASK |
> +                                       GQSPI_IER_TXNOT_FULL_MASK);
> +
> +       if (xqspi->rxbuf != NULL) {
> +               /* Enable interrupts for RX */
> +               if (xqspi->mode == GQSPI_MODE_DMA) {
> +                       /* Enable DMA interrupts */
> +                       zynqmp_gqspi_write(xqspi,
> +                                       GQSPI_QSPIDMA_DST_I_EN_OFST,
> +                                       GQSPI_QSPIDMA_DST_I_EN_DONE_MASK);
> +               } else {
> +                       zynqmp_gqspi_write(xqspi, GQSPI_IER_OFST,
> +                                       GQSPI_IER_GENFIFOEMPTY_MASK |
> +                                       GQSPI_IER_RXNEMPTY_MASK |
> +                                       GQSPI_IER_RXEMPTY_MASK);
> +               }
> +       }
> +
> +       return transfer->len;
> +}
> +
> +/**
> + * zynqmp_qspi_suspend:        Suspend method for the QSPI driver
> + * @_dev:      Address of the platform_device structure
> + *
> + * This function stops the QSPI driver queue and disables the QSPI controller
> + *
> + * Return:     Always 0
> + */
> +static int __maybe_unused zynqmp_qspi_suspend(struct device *dev)
> +{
> +       struct platform_device *pdev = container_of(dev,
> +                                                   struct platform_device,
> +                                                   dev);
> +       struct spi_master *master = platform_get_drvdata(pdev);
> +
> +       spi_master_suspend(master);
> +
> +       zynqmp_unprepare_transfer_hardware(master);
> +
> +       return 0;
> +}
> +
> +/**
> + * zynqmp_qspi_resume: Resume method for the QSPI driver
> + * @dev:       Address of the platform_device structure
> + *
> + * The function starts the QSPI driver queue and initializes the QSPI
> + * controller
> + *
> + * Return:     0 on success and error value on error
> + */
> +static int __maybe_unused zynqmp_qspi_resume(struct device *dev)
> +{
> +       struct platform_device *pdev = container_of(dev,
> +                                                   struct platform_device,
> +                                                   dev);
> +       struct spi_master *master = platform_get_drvdata(pdev);
> +       struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
> +       int ret = 0;

is the initialisation required

> +
> +       ret = clk_enable(xqspi->pclk);
> +       if (ret) {
> +               dev_err(dev, "Cannot enable APB clock.\n");
> +               return ret;
> +       }
> +
> +       ret = clk_enable(xqspi->refclk);
> +       if (ret) {
> +               dev_err(dev, "Cannot enable device clock.\n");
> +               clk_disable(xqspi->pclk);
> +               return ret;
> +       }
> +
> +       spi_master_resume(master);
> +
> +       return 0;
> +}
> +
> +static SIMPLE_DEV_PM_OPS(zynqmp_qspi_dev_pm_ops, zynqmp_qspi_suspend,
> +                        zynqmp_qspi_resume);
> +
> +/**
> + * zynqmp_qspi_probe:  Probe method for the QSPI driver
> + * @pdev:      Pointer to the platform_device structure
> + *
> + * This function initializes the driver data structures and the hardware.
> + *
> + * Return:     0 on success and error value on failure
> + */
> +static int zynqmp_qspi_probe(struct platform_device *pdev)
> +{
> +       int ret = 0;
> +       struct spi_master *master;
> +       struct zynqmp_qspi *xqspi;
> +       struct resource *res;
> +       struct device *dev = &pdev->dev;
> +
> +       master = spi_alloc_master(&pdev->dev, sizeof(*xqspi));
> +       if (!master)
> +               return -ENOMEM;
> +
> +       xqspi = spi_master_get_devdata(master);
> +       master->dev.of_node = pdev->dev.of_node;
> +       platform_set_drvdata(pdev, master);
> +
> +       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +       xqspi->regs = devm_ioremap_resource(&pdev->dev, res);
> +       if (IS_ERR(xqspi->regs)) {
> +               ret = PTR_ERR(xqspi->regs);
> +               goto remove_master;
> +       }
> +
> +       xqspi->dev = dev;
> +       xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
> +       if (IS_ERR(xqspi->pclk)) {
> +               dev_err(dev, "pclk clock not found.\n");
> +               ret = PTR_ERR(xqspi->pclk);
> +               goto remove_master;
> +       }
> +
> +       xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
> +       if (IS_ERR(xqspi->refclk)) {
> +               dev_err(dev, "ref_clk clock not found.\n");
> +               ret = PTR_ERR(xqspi->refclk);
> +               goto remove_master;
> +       }
> +
> +       ret = clk_prepare_enable(xqspi->pclk);
> +       if (ret) {
> +               dev_err(dev, "Unable to enable APB clock.\n");
> +               goto remove_master;
> +       }
> +
> +       ret = clk_prepare_enable(xqspi->refclk);
> +       if (ret) {
> +               dev_err(dev, "Unable to enable device clock.\n");
> +               goto clk_dis_pclk;
> +       }
> +
> +       /* QSPI controller initializations */
> +       zynqmp_qspi_init_hw(xqspi);
> +
> +       xqspi->irq = platform_get_irq(pdev, 0);
> +       if (xqspi->irq <= 0) {
> +               ret = -ENXIO;
> +               dev_err(dev, "irq resource not found\n");
> +               goto remove_master;
> +       }
> +       ret = devm_request_irq(&pdev->dev, xqspi->irq, zynqmp_qspi_irq,
> +                              0, pdev->name, master);
> +       if (ret != 0) {
> +               ret = -ENXIO;
> +               dev_err(dev, "request_irq failed\n");
> +               goto remove_master;
> +       }

Shouldnt the clk disable be called here.


> +       if (master->dev.parent == NULL)
> +               master->dev.parent = &master->dev;
> +
> +       ret = spi_register_master(master);
> +       if (ret)
> +               goto clk_dis_all;
> +
> +       return 0;
> +
> +clk_dis_all:
> +       clk_disable_unprepare(xqspi->refclk);
> +clk_dis_pclk:
> +       clk_disable_unprepare(xqspi->pclk);
> +remove_master:
> +       spi_master_put(master);
> +
> +       return ret;
> +}
> +
> +/**
> + * zynqmp_qspi_remove: Remove method for the QSPI driver
> + * @pdev:      Pointer to the platform_device structure
> + *
> + * This function is called if a device is physically removed from the system or
> + * if the driver module is being unloaded. It frees all resources allocated to
> + * the device.
> + *
> + * Return:     0 Always
> + */
> +static int zynqmp_qspi_remove(struct platform_device *pdev)
> +{
> +       struct spi_master *master = platform_get_drvdata(pdev);
> +       struct zynqmp_qspi *xqspi = spi_master_get_devdata(master);
> +
> +       zynqmp_gqspi_write(xqspi, GQSPI_EN_OFST, 0x0);
> +       clk_disable_unprepare(xqspi->refclk);
> +       clk_disable_unprepare(xqspi->pclk);
> +
> +       spi_unregister_master(master);
> +
> +       return 0;
> +}
> +
> +static const struct of_device_id zynqmp_qspi_of_match[] = {
> +       { .compatible = "xlnx,zynqmp-qspi-1.0", },
> +       { /* End of table */ }
> +};
> +
> +MODULE_DEVICE_TABLE(of, zynqmp_qspi_of_match);
> +
> +static struct platform_driver zynqmp_qspi_driver = {
> +       .probe = zynqmp_qspi_probe,
> +       .remove = zynqmp_qspi_remove,
> +       .driver = {
> +               .name = "zynqmp-qspi",
> +               .of_match_table = zynqmp_qspi_of_match,
> +               .pm = &zynqmp_qspi_dev_pm_ops,
> +       },
> +};
> +
> +module_platform_driver(zynqmp_qspi_driver);
> +
> +MODULE_AUTHOR("Xilinx, Inc.");
> +MODULE_DESCRIPTION("Xilinx Zynqmp QSPI driver");
> +MODULE_LICENSE("GPL");
> --
> 2.1.2
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
--
To unsubscribe from this list: send the line "unsubscribe linux-spi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html