[PATCH v2 2/4] xilinx_spi: Switch to iomem functions and support little endian.
Grant Likely
grant.likely at secretlab.ca
Fri Nov 13 01:59:52 EST 2009
On Thu, Nov 12, 2009 at 7:26 AM, Richard Röjfors
<richard.rojfors at mocean-labs.com> wrote:
> This patch changes the out_(be)(8|16|32) and in_(be)(8|16|32) calls to 32 bits ioread/iowrite.
>
> The read and write function are attached to the internal struct as callbacks, callback
> is selected depending on endianess.
>
> This will also build on platforms not supporting the in/out calls for instance x86.
>
> Signed-off-by: Richard Röjfors <richard.rojfors at mocean-labs.com>
On brief review looks good to me.
Acked-by: Grant Likely <grant.likely at secretlab.ca>
> ---
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index e60b264..9667650 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -236,7 +236,7 @@ config SPI_TXX9
>
> config SPI_XILINX
> tristate "Xilinx SPI controller"
> - depends on EXPERIMENTAL
> + depends on HAS_IOMEM && EXPERIMENTAL
> select SPI_BITBANG
> help
> This exposes the SPI controller IP from the Xilinx EDK.
> diff --git a/drivers/spi/xilinx_spi.c b/drivers/spi/xilinx_spi.c
> index 5761a4c..d0ca13a 100644
> --- a/drivers/spi/xilinx_spi.c
> +++ b/drivers/spi/xilinx_spi.c
> @@ -27,7 +27,7 @@
> /* Register definitions as per "OPB Serial Peripheral Interface (SPI) (v1.00e)
> * Product Specification", DS464
> */
> -#define XSPI_CR_OFFSET 0x62 /* 16-bit Control Register */
> +#define XSPI_CR_OFFSET 0x60 /* 16-bit Control Register */
>
> #define XSPI_CR_ENABLE 0x02
> #define XSPI_CR_MASTER_MODE 0x04
> @@ -39,7 +39,7 @@
> #define XSPI_CR_MANUAL_SSELECT 0x80
> #define XSPI_CR_TRANS_INHIBIT 0x100
>
> -#define XSPI_SR_OFFSET 0x67 /* 8-bit Status Register */
> +#define XSPI_SR_OFFSET 0x64 /* 8-bit Status Register */
>
> #define XSPI_SR_RX_EMPTY_MASK 0x01 /* Receive FIFO is empty */
> #define XSPI_SR_RX_FULL_MASK 0x02 /* Receive FIFO is full */
> @@ -47,8 +47,8 @@
> #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 0x6b /* 8-bit Data Transmit Register */
> -#define XSPI_RXD_OFFSET 0x6f /* 8-bit Data Receive Register */
> +#define XSPI_TXD_OFFSET 0x68 /* 8-bit Data Transmit Register */
> +#define XSPI_RXD_OFFSET 0x6c /* 8-bit Data Receive Register */
>
> #define XSPI_SSR_OFFSET 0x70 /* 32-bit Slave Select Register */
>
> @@ -86,25 +86,29 @@ struct xilinx_spi {
> 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 */
> + unsigned int (*read_fn) (void __iomem *);
> + void (*write_fn) (u32, void __iomem *);
> };
>
> -static void xspi_init_hw(void __iomem *regs_base)
> +static void xspi_init_hw(struct xilinx_spi *xspi)
> {
> + void __iomem *regs_base = xspi->regs;
> +
> /* Reset the SPI device */
> - out_be32(regs_base + XIPIF_V123B_RESETR_OFFSET,
> - XIPIF_V123B_RESET_MASK);
> + xspi->write_fn(XIPIF_V123B_RESET_MASK,
> + regs_base + XIPIF_V123B_RESETR_OFFSET);
> /* Disable all the interrupts just in case */
> - out_be32(regs_base + XIPIF_V123B_IIER_OFFSET, 0);
> + xspi->write_fn(0, regs_base + XIPIF_V123B_IIER_OFFSET);
> /* Enable the global IPIF interrupt */
> - out_be32(regs_base + XIPIF_V123B_DGIER_OFFSET,
> - XIPIF_V123B_GINTR_ENABLE);
> + xspi->write_fn(XIPIF_V123B_GINTR_ENABLE,
> + regs_base + XIPIF_V123B_DGIER_OFFSET);
> /* Deselect the slave on the SPI bus */
> - out_be32(regs_base + XSPI_SSR_OFFSET, 0xffff);
> + xspi->write_fn(0xffff, regs_base + XSPI_SSR_OFFSET);
> /* Disable the transmitter, enable Manual Slave Select Assertion,
> * put SPI controller into master mode, and enable it */
> - out_be16(regs_base + XSPI_CR_OFFSET,
> - XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT
> - | XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE);
> + xspi->write_fn(XSPI_CR_TRANS_INHIBIT | XSPI_CR_MANUAL_SSELECT |
> + XSPI_CR_MASTER_MODE | XSPI_CR_ENABLE,
> + regs_base + XSPI_CR_OFFSET);
> }
>
> static void xilinx_spi_chipselect(struct spi_device *spi, int is_on)
> @@ -113,16 +117,16 @@ static void xilinx_spi_chipselect(struct spi_device *spi, int is_on)
>
> if (is_on == BITBANG_CS_INACTIVE) {
> /* Deselect the slave on the SPI bus */
> - out_be32(xspi->regs + XSPI_SSR_OFFSET, 0xffff);
> + xspi->write_fn(0xffff, xspi->regs + XSPI_SSR_OFFSET);
> } else if (is_on == BITBANG_CS_ACTIVE) {
> /* Set the SPI clock phase and polarity */
> - u16 cr = in_be16(xspi->regs + XSPI_CR_OFFSET)
> + u16 cr = xspi->read_fn(xspi->regs + XSPI_CR_OFFSET)
> & ~XSPI_CR_MODE_MASK;
> if (spi->mode & SPI_CPHA)
> cr |= XSPI_CR_CPHA;
> if (spi->mode & SPI_CPOL)
> cr |= XSPI_CR_CPOL;
> - out_be16(xspi->regs + XSPI_CR_OFFSET, cr);
> + xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
>
> /* We do not check spi->max_speed_hz here as the SPI clock
> * frequency is not software programmable (the IP block design
> @@ -130,8 +134,8 @@ static void xilinx_spi_chipselect(struct spi_device *spi, int is_on)
> */
>
> /* Activate the chip select */
> - out_be32(xspi->regs + XSPI_SSR_OFFSET,
> - ~(0x0001 << spi->chip_select));
> + xspi->write_fn(~(0x0001 << spi->chip_select),
> + xspi->regs + XSPI_SSR_OFFSET);
> }
> }
>
> @@ -177,15 +181,15 @@ static void xilinx_spi_fill_tx_fifo(struct xilinx_spi *xspi)
> u8 sr;
>
> /* Fill the Tx FIFO with as many bytes as possible */
> - sr = in_8(xspi->regs + XSPI_SR_OFFSET);
> + 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) {
> - out_8(xspi->regs + XSPI_TXD_OFFSET, *xspi->tx_ptr++);
> - } else {
> - out_8(xspi->regs + XSPI_TXD_OFFSET, 0);
> - }
> + if (xspi->tx_ptr)
> + xspi->write_fn(*xspi->tx_ptr++,
> + xspi->regs + XSPI_TXD_OFFSET);
> + else
> + xspi->write_fn(0, xspi->regs + XSPI_TXD_OFFSET);
> xspi->remaining_bytes--;
> - sr = in_8(xspi->regs + XSPI_SR_OFFSET);
> + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
> }
> }
>
> @@ -207,18 +211,19 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
> /* Enable the transmit empty interrupt, which we use to determine
> * progress on the transmission.
> */
> - ipif_ier = in_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET);
> - out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET,
> - ipif_ier | XSPI_INTR_TX_EMPTY);
> + ipif_ier = xspi->read_fn(xspi->regs + XIPIF_V123B_IIER_OFFSET);
> + 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 = in_be16(xspi->regs + XSPI_CR_OFFSET) & ~XSPI_CR_TRANS_INHIBIT;
> - out_be16(xspi->regs + XSPI_CR_OFFSET, cr);
> + 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);
>
> /* Disable the transmit empty interrupt */
> - out_be32(xspi->regs + XIPIF_V123B_IIER_OFFSET, ipif_ier);
> + xspi->write_fn(ipif_ier, xspi->regs + XIPIF_V123B_IIER_OFFSET);
>
> return t->len - xspi->remaining_bytes;
> }
> @@ -235,8 +240,8 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id)
> u32 ipif_isr;
>
> /* Get the IPIF interrupts, and clear them immediately */
> - ipif_isr = in_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET);
> - out_be32(xspi->regs + XIPIF_V123B_IISR_OFFSET, ipif_isr);
> + ipif_isr = xspi->read_fn(xspi->regs + XIPIF_V123B_IISR_OFFSET);
> + xspi->write_fn(ipif_isr, xspi->regs + XIPIF_V123B_IISR_OFFSET);
>
> if (ipif_isr & XSPI_INTR_TX_EMPTY) { /* Transmission completed */
> u16 cr;
> @@ -247,20 +252,20 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id)
> * transmitter while the Isr refills the transmit register/FIFO,
> * or make sure it is stopped if we're done.
> */
> - cr = in_be16(xspi->regs + XSPI_CR_OFFSET);
> - out_be16(xspi->regs + XSPI_CR_OFFSET,
> - cr | XSPI_CR_TRANS_INHIBIT);
> + 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 = in_8(xspi->regs + XSPI_SR_OFFSET);
> + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
> while ((sr & XSPI_SR_RX_EMPTY_MASK) == 0) {
> u8 data;
>
> - data = in_8(xspi->regs + XSPI_RXD_OFFSET);
> + data = xspi->read_fn(xspi->regs + XSPI_RXD_OFFSET);
> if (xspi->rx_ptr) {
> *xspi->rx_ptr++ = data;
> }
> - sr = in_8(xspi->regs + XSPI_SR_OFFSET);
> + sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
> }
>
> /* See if there is more data to send */
> @@ -269,7 +274,7 @@ static irqreturn_t xilinx_spi_irq(int irq, void *dev_id)
> /* Start the transfer by not inhibiting the
> * transmitter any longer
> */
> - out_be16(xspi->regs + XSPI_CR_OFFSET, cr);
> + xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
> } else {
> /* No more data to send.
> * Indicate the transfer is completed.
> @@ -324,9 +329,16 @@ struct spi_master *xilinx_spi_init(struct device *dev, struct resource *mem,
>
> xspi->mem = *mem;
> xspi->irq = irq;
> + if (pdata->little_endian) {
> + xspi->read_fn = ioread32;
> + xspi->write_fn = iowrite32;
> + } else {
> + xspi->read_fn = ioread32be;
> + xspi->write_fn = iowrite32be;
> + }
>
> /* SPI controller initializations */
> - xspi_init_hw(xspi->regs);
> + xspi_init_hw(xspi);
>
> /* Register for SPI Interrupt */
> ret = request_irq(xspi->irq, xilinx_spi_irq, 0, XILINX_SPI_NAME, xspi);
> diff --git a/include/linux/spi/xilinx_spi.h b/include/linux/spi/xilinx_spi.h
> index 06df0ab..a705ad8 100644
> --- a/include/linux/spi/xilinx_spi.h
> +++ b/include/linux/spi/xilinx_spi.h
> @@ -4,11 +4,13 @@
> /**
> * struct xspi_platform_data - Platform data of the Xilinx SPI driver
> * @num_chipselect: Number of chip select by the IP
> + * @little_endian If registers should be accessed little endian or not
> * @devices: Devices to add when the driver is probed.
> * @num_devices: Number of devices in the devices array.
> */
> struct xspi_platform_data {
> u16 num_chipselect;
> + bool little_endian;
> struct spi_board_info *devices;
> u8 num_devices;
> };
>
--
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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