linux/drivers/spi/spi-zynq-qspi.c
Miquel Raynal d575c9b7c8
spi: zynq-qspi: Support two chip selects
The Zynq QSPI controller features 2 CS. When the num-cs DT property
is set to 2, the hardware will be initialized to support having two
devices connected over each CS.

In this case, both CS lines are driven by the state of the U_PAGE
(upper page) bit. When unset, the lower page (CS0) is selected,
otherwise it is the upper page (CS1).

Change tested on a custom design featuring two SPI-NORs with different
CS on the Zynq-7000 QSPI bus.

Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20191108140744.1734-8-miquel.raynal@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2019-11-08 17:45:09 +00:00

775 lines
23 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2019 Xilinx, Inc.
*
* Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>
#include <linux/spi/spi-mem.h>
/* Register offset definitions */
#define ZYNQ_QSPI_CONFIG_OFFSET 0x00 /* Configuration Register, RW */
#define ZYNQ_QSPI_STATUS_OFFSET 0x04 /* Interrupt Status Register, RO */
#define ZYNQ_QSPI_IEN_OFFSET 0x08 /* Interrupt Enable Register, WO */
#define ZYNQ_QSPI_IDIS_OFFSET 0x0C /* Interrupt Disable Reg, WO */
#define ZYNQ_QSPI_IMASK_OFFSET 0x10 /* Interrupt Enabled Mask Reg,RO */
#define ZYNQ_QSPI_ENABLE_OFFSET 0x14 /* Enable/Disable Register, RW */
#define ZYNQ_QSPI_DELAY_OFFSET 0x18 /* Delay Register, RW */
#define ZYNQ_QSPI_TXD_00_00_OFFSET 0x1C /* Transmit 4-byte inst, WO */
#define ZYNQ_QSPI_TXD_00_01_OFFSET 0x80 /* Transmit 1-byte inst, WO */
#define ZYNQ_QSPI_TXD_00_10_OFFSET 0x84 /* Transmit 2-byte inst, WO */
#define ZYNQ_QSPI_TXD_00_11_OFFSET 0x88 /* Transmit 3-byte inst, WO */
#define ZYNQ_QSPI_RXD_OFFSET 0x20 /* Data Receive Register, RO */
#define ZYNQ_QSPI_SIC_OFFSET 0x24 /* Slave Idle Count Register, RW */
#define ZYNQ_QSPI_TX_THRESH_OFFSET 0x28 /* TX FIFO Watermark Reg, RW */
#define ZYNQ_QSPI_RX_THRESH_OFFSET 0x2C /* RX FIFO Watermark Reg, RW */
#define ZYNQ_QSPI_GPIO_OFFSET 0x30 /* GPIO Register, RW */
#define ZYNQ_QSPI_LINEAR_CFG_OFFSET 0xA0 /* Linear Adapter Config Ref, RW */
#define ZYNQ_QSPI_MOD_ID_OFFSET 0xFC /* Module ID Register, RO */
/*
* QSPI Configuration Register bit Masks
*
* This register contains various control bits that effect the operation
* of the QSPI controller
*/
#define ZYNQ_QSPI_CONFIG_IFMODE_MASK BIT(31) /* Flash Memory Interface */
#define ZYNQ_QSPI_CONFIG_MANSRT_MASK BIT(16) /* Manual TX Start */
#define ZYNQ_QSPI_CONFIG_MANSRTEN_MASK BIT(15) /* Enable Manual TX Mode */
#define ZYNQ_QSPI_CONFIG_SSFORCE_MASK BIT(14) /* Manual Chip Select */
#define ZYNQ_QSPI_CONFIG_BDRATE_MASK GENMASK(5, 3) /* Baud Rate Mask */
#define ZYNQ_QSPI_CONFIG_CPHA_MASK BIT(2) /* Clock Phase Control */
#define ZYNQ_QSPI_CONFIG_CPOL_MASK BIT(1) /* Clock Polarity Control */
#define ZYNQ_QSPI_CONFIG_FWIDTH_MASK GENMASK(7, 6) /* FIFO width */
#define ZYNQ_QSPI_CONFIG_MSTREN_MASK BIT(0) /* Master Mode */
/*
* QSPI Configuration Register - Baud rate and slave select
*
* These are the values used in the calculation of baud rate divisor and
* setting the slave select.
*/
#define ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX GENMASK(2, 0) /* Baud rate maximum */
#define ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT 3 /* Baud rate divisor shift */
#define ZYNQ_QSPI_CONFIG_PCS BIT(10) /* Peripheral Chip Select */
/*
* QSPI Interrupt Registers bit Masks
*
* All the four interrupt registers (Status/Mask/Enable/Disable) have the same
* bit definitions.
*/
#define ZYNQ_QSPI_IXR_RX_OVERFLOW_MASK BIT(0) /* QSPI RX FIFO Overflow */
#define ZYNQ_QSPI_IXR_TXNFULL_MASK BIT(2) /* QSPI TX FIFO Overflow */
#define ZYNQ_QSPI_IXR_TXFULL_MASK BIT(3) /* QSPI TX FIFO is full */
#define ZYNQ_QSPI_IXR_RXNEMTY_MASK BIT(4) /* QSPI RX FIFO Not Empty */
#define ZYNQ_QSPI_IXR_RXF_FULL_MASK BIT(5) /* QSPI RX FIFO is full */
#define ZYNQ_QSPI_IXR_TXF_UNDRFLOW_MASK BIT(6) /* QSPI TX FIFO Underflow */
#define ZYNQ_QSPI_IXR_ALL_MASK (ZYNQ_QSPI_IXR_RX_OVERFLOW_MASK | \
ZYNQ_QSPI_IXR_TXNFULL_MASK | \
ZYNQ_QSPI_IXR_TXFULL_MASK | \
ZYNQ_QSPI_IXR_RXNEMTY_MASK | \
ZYNQ_QSPI_IXR_RXF_FULL_MASK | \
ZYNQ_QSPI_IXR_TXF_UNDRFLOW_MASK)
#define ZYNQ_QSPI_IXR_RXTX_MASK (ZYNQ_QSPI_IXR_TXNFULL_MASK | \
ZYNQ_QSPI_IXR_RXNEMTY_MASK)
/*
* QSPI Enable Register bit Masks
*
* This register is used to enable or disable the QSPI controller
*/
#define ZYNQ_QSPI_ENABLE_ENABLE_MASK BIT(0) /* QSPI Enable Bit Mask */
/*
* QSPI Linear Configuration Register
*
* It is named Linear Configuration but it controls other modes when not in
* linear mode also.
*/
#define ZYNQ_QSPI_LCFG_TWO_MEM BIT(30) /* LQSPI Two memories */
#define ZYNQ_QSPI_LCFG_SEP_BUS BIT(29) /* LQSPI Separate bus */
#define ZYNQ_QSPI_LCFG_U_PAGE BIT(28) /* LQSPI Upper Page */
#define ZYNQ_QSPI_LCFG_DUMMY_SHIFT 8
#define ZYNQ_QSPI_FAST_READ_QOUT_CODE 0x6B /* read instruction code */
#define ZYNQ_QSPI_FIFO_DEPTH 63 /* FIFO depth in words */
#define ZYNQ_QSPI_RX_THRESHOLD 32 /* Rx FIFO threshold level */
#define ZYNQ_QSPI_TX_THRESHOLD 1 /* Tx FIFO threshold level */
/*
* The modebits configurable by the driver to make the SPI support different
* data formats
*/
#define ZYNQ_QSPI_MODEBITS (SPI_CPOL | SPI_CPHA)
/* Maximum number of chip selects */
#define ZYNQ_QSPI_MAX_NUM_CS 2
/**
* struct zynq_qspi - Defines qspi driver instance
* @regs: Virtual address of the QSPI controller registers
* @refclk: Pointer to the peripheral clock
* @pclk: Pointer to the APB clock
* @irq: IRQ number
* @txbuf: Pointer to the TX buffer
* @rxbuf: Pointer to the RX buffer
* @tx_bytes: Number of bytes left to transfer
* @rx_bytes: Number of bytes left to receive
* @data_completion: completion structure
*/
struct zynq_qspi {
struct device *dev;
void __iomem *regs;
struct clk *refclk;
struct clk *pclk;
int irq;
u8 *txbuf;
u8 *rxbuf;
int tx_bytes;
int rx_bytes;
struct completion data_completion;
};
/*
* Inline functions for the QSPI controller read/write
*/
static inline u32 zynq_qspi_read(struct zynq_qspi *xqspi, u32 offset)
{
return readl_relaxed(xqspi->regs + offset);
}
static inline void zynq_qspi_write(struct zynq_qspi *xqspi, u32 offset,
u32 val)
{
writel_relaxed(val, xqspi->regs + offset);
}
/**
* zynq_qspi_init_hw - Initialize the hardware
* @xqspi: Pointer to the zynq_qspi structure
* @num_cs: Number of connected CS (to enable dual memories if needed)
*
* The default settings of the QSPI controller's configurable parameters on
* reset are
* - Master mode
* - Baud rate divisor is set to 2
* - Tx threshold set to 1l Rx threshold set to 32
* - Flash memory interface mode enabled
* - Size of the word to be transferred as 8 bit
* This function performs the following actions
* - Disable and clear all the interrupts
* - Enable manual slave select
* - Enable manual start
* - Deselect all the chip select lines
* - Set the size of the word to be transferred as 32 bit
* - Set the little endian mode of TX FIFO and
* - Enable the QSPI controller
*/
static void zynq_qspi_init_hw(struct zynq_qspi *xqspi, unsigned int num_cs)
{
u32 config_reg;
zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET, 0);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IDIS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK);
/* Disable linear mode as the boot loader may have used it */
config_reg = 0;
/* At the same time, enable dual mode if more than 1 CS is available */
if (num_cs > 1)
config_reg |= ZYNQ_QSPI_LCFG_TWO_MEM;
zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
/* Clear the RX FIFO */
while (zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET) &
ZYNQ_QSPI_IXR_RXNEMTY_MASK)
zynq_qspi_read(xqspi, ZYNQ_QSPI_RXD_OFFSET);
zynq_qspi_write(xqspi, ZYNQ_QSPI_STATUS_OFFSET, ZYNQ_QSPI_IXR_ALL_MASK);
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
config_reg &= ~(ZYNQ_QSPI_CONFIG_MSTREN_MASK |
ZYNQ_QSPI_CONFIG_CPOL_MASK |
ZYNQ_QSPI_CONFIG_CPHA_MASK |
ZYNQ_QSPI_CONFIG_BDRATE_MASK |
ZYNQ_QSPI_CONFIG_SSFORCE_MASK |
ZYNQ_QSPI_CONFIG_MANSRTEN_MASK |
ZYNQ_QSPI_CONFIG_MANSRT_MASK);
config_reg |= (ZYNQ_QSPI_CONFIG_MSTREN_MASK |
ZYNQ_QSPI_CONFIG_SSFORCE_MASK |
ZYNQ_QSPI_CONFIG_FWIDTH_MASK |
ZYNQ_QSPI_CONFIG_IFMODE_MASK);
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
zynq_qspi_write(xqspi, ZYNQ_QSPI_RX_THRESH_OFFSET,
ZYNQ_QSPI_RX_THRESHOLD);
zynq_qspi_write(xqspi, ZYNQ_QSPI_TX_THRESH_OFFSET,
ZYNQ_QSPI_TX_THRESHOLD);
zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET,
ZYNQ_QSPI_ENABLE_ENABLE_MASK);
}
static bool zynq_qspi_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
if (!spi_mem_default_supports_op(mem, op))
return false;
/*
* The number of address bytes should be equal to or less than 3 bytes.
*/
if (op->addr.nbytes > 3)
return false;
return true;
}
/**
* zynq_qspi_rxfifo_op - Read 1..4 bytes from RxFIFO to RX buffer
* @xqspi: Pointer to the zynq_qspi structure
* @size: Number of bytes to be read (1..4)
*/
static void zynq_qspi_rxfifo_op(struct zynq_qspi *xqspi, unsigned int size)
{
u32 data;
data = zynq_qspi_read(xqspi, ZYNQ_QSPI_RXD_OFFSET);
if (xqspi->rxbuf) {
memcpy(xqspi->rxbuf, ((u8 *)&data) + 4 - size, size);
xqspi->rxbuf += size;
}
xqspi->rx_bytes -= size;
if (xqspi->rx_bytes < 0)
xqspi->rx_bytes = 0;
}
/**
* zynq_qspi_txfifo_op - Write 1..4 bytes from TX buffer to TxFIFO
* @xqspi: Pointer to the zynq_qspi structure
* @size: Number of bytes to be written (1..4)
*/
static void zynq_qspi_txfifo_op(struct zynq_qspi *xqspi, unsigned int size)
{
static const unsigned int offset[4] = {
ZYNQ_QSPI_TXD_00_01_OFFSET, ZYNQ_QSPI_TXD_00_10_OFFSET,
ZYNQ_QSPI_TXD_00_11_OFFSET, ZYNQ_QSPI_TXD_00_00_OFFSET };
u32 data;
if (xqspi->txbuf) {
data = 0xffffffff;
memcpy(&data, xqspi->txbuf, size);
xqspi->txbuf += size;
} else {
data = 0;
}
xqspi->tx_bytes -= size;
zynq_qspi_write(xqspi, offset[size - 1], data);
}
/**
* zynq_qspi_chipselect - Select or deselect the chip select line
* @spi: Pointer to the spi_device structure
* @assert: 1 for select or 0 for deselect the chip select line
*/
static void zynq_qspi_chipselect(struct spi_device *spi, bool assert)
{
struct spi_controller *ctlr = spi->master;
struct zynq_qspi *xqspi = spi_controller_get_devdata(ctlr);
u32 config_reg;
/* Select the lower (CS0) or upper (CS1) memory */
if (ctlr->num_chipselect > 1) {
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET);
if (!spi->chip_select)
config_reg &= ~ZYNQ_QSPI_LCFG_U_PAGE;
else
config_reg |= ZYNQ_QSPI_LCFG_U_PAGE;
zynq_qspi_write(xqspi, ZYNQ_QSPI_LINEAR_CFG_OFFSET, config_reg);
}
/* Ground the line to assert the CS */
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
if (assert)
config_reg &= ~ZYNQ_QSPI_CONFIG_PCS;
else
config_reg |= ZYNQ_QSPI_CONFIG_PCS;
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
}
/**
* zynq_qspi_config_op - Configure QSPI controller for specified transfer
* @xqspi: Pointer to the zynq_qspi structure
* @qspi: Pointer to the spi_device structure
*
* Sets the operational mode of QSPI controller for the next QSPI transfer and
* sets the requested clock frequency.
*
* Return: 0 on success and -EINVAL on invalid input parameter
*
* Note: If the requested frequency is not an exact match with what can be
* obtained using the prescalar 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 zynq_qspi_config_op(struct zynq_qspi *xqspi, struct spi_device *spi)
{
u32 config_reg, baud_rate_val = 0;
/*
* Set the clock frequency
* The baud rate divisor is not a direct mapping to the value written
* into the configuration register (config_reg[5:3])
* i.e. 000 - divide by 2
* 001 - divide by 4
* ----------------
* 111 - divide by 256
*/
while ((baud_rate_val < ZYNQ_QSPI_CONFIG_BAUD_DIV_MAX) &&
(clk_get_rate(xqspi->refclk) / (2 << baud_rate_val)) >
spi->max_speed_hz)
baud_rate_val++;
config_reg = zynq_qspi_read(xqspi, ZYNQ_QSPI_CONFIG_OFFSET);
/* Set the QSPI clock phase and clock polarity */
config_reg &= (~ZYNQ_QSPI_CONFIG_CPHA_MASK) &
(~ZYNQ_QSPI_CONFIG_CPOL_MASK);
if (spi->mode & SPI_CPHA)
config_reg |= ZYNQ_QSPI_CONFIG_CPHA_MASK;
if (spi->mode & SPI_CPOL)
config_reg |= ZYNQ_QSPI_CONFIG_CPOL_MASK;
config_reg &= ~ZYNQ_QSPI_CONFIG_BDRATE_MASK;
config_reg |= (baud_rate_val << ZYNQ_QSPI_CONFIG_BAUD_DIV_SHIFT);
zynq_qspi_write(xqspi, ZYNQ_QSPI_CONFIG_OFFSET, config_reg);
return 0;
}
/**
* zynq_qspi_setup - Configure the QSPI controller
* @spi: 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 on success and error value on failure
*/
static int zynq_qspi_setup_op(struct spi_device *spi)
{
struct spi_controller *ctlr = spi->master;
struct zynq_qspi *qspi = spi_controller_get_devdata(ctlr);
if (ctlr->busy)
return -EBUSY;
clk_enable(qspi->refclk);
clk_enable(qspi->pclk);
zynq_qspi_write(qspi, ZYNQ_QSPI_ENABLE_OFFSET,
ZYNQ_QSPI_ENABLE_ENABLE_MASK);
return 0;
}
/**
* zynq_qspi_write_op - Fills the TX FIFO with as many bytes as possible
* @xqspi: Pointer to the zynq_qspi structure
* @txcount: Maximum number of words to write
* @txempty: Indicates that TxFIFO is empty
*/
static void zynq_qspi_write_op(struct zynq_qspi *xqspi, int txcount,
bool txempty)
{
int count, len, k;
len = xqspi->tx_bytes;
if (len && len < 4) {
/*
* We must empty the TxFIFO between accesses to TXD0,
* TXD1, TXD2, TXD3.
*/
if (txempty)
zynq_qspi_txfifo_op(xqspi, len);
return;
}
count = len / 4;
if (count > txcount)
count = txcount;
if (xqspi->txbuf) {
iowrite32_rep(xqspi->regs + ZYNQ_QSPI_TXD_00_00_OFFSET,
xqspi->txbuf, count);
xqspi->txbuf += count * 4;
} else {
for (k = 0; k < count; k++)
writel_relaxed(0, xqspi->regs +
ZYNQ_QSPI_TXD_00_00_OFFSET);
}
xqspi->tx_bytes -= count * 4;
}
/**
* zynq_qspi_read_op - Drains the RX FIFO by as many bytes as possible
* @xqspi: Pointer to the zynq_qspi structure
* @rxcount: Maximum number of words to read
*/
static void zynq_qspi_read_op(struct zynq_qspi *xqspi, int rxcount)
{
int count, len, k;
len = xqspi->rx_bytes - xqspi->tx_bytes;
count = len / 4;
if (count > rxcount)
count = rxcount;
if (xqspi->rxbuf) {
ioread32_rep(xqspi->regs + ZYNQ_QSPI_RXD_OFFSET,
xqspi->rxbuf, count);
xqspi->rxbuf += count * 4;
} else {
for (k = 0; k < count; k++)
readl_relaxed(xqspi->regs + ZYNQ_QSPI_RXD_OFFSET);
}
xqspi->rx_bytes -= count * 4;
len -= count * 4;
if (len && len < 4 && count < rxcount)
zynq_qspi_rxfifo_op(xqspi, len);
}
/**
* zynq_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 zynq_qspi_irq(int irq, void *dev_id)
{
u32 intr_status;
bool txempty;
struct zynq_qspi *xqspi = (struct zynq_qspi *)dev_id;
intr_status = zynq_qspi_read(xqspi, ZYNQ_QSPI_STATUS_OFFSET);
zynq_qspi_write(xqspi, ZYNQ_QSPI_STATUS_OFFSET, intr_status);
if ((intr_status & ZYNQ_QSPI_IXR_TXNFULL_MASK) ||
(intr_status & ZYNQ_QSPI_IXR_RXNEMTY_MASK)) {
/*
* This bit is set when Tx FIFO has < THRESHOLD entries.
* We have the THRESHOLD value set to 1,
* so this bit indicates Tx FIFO is empty.
*/
txempty = !!(intr_status & ZYNQ_QSPI_IXR_TXNFULL_MASK);
/* Read out the data from the RX FIFO */
zynq_qspi_read_op(xqspi, ZYNQ_QSPI_RX_THRESHOLD);
if (xqspi->tx_bytes) {
/* There is more data to send */
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_RX_THRESHOLD,
txempty);
} else {
/*
* If transfer and receive is completed then only send
* complete signal.
*/
if (!xqspi->rx_bytes) {
zynq_qspi_write(xqspi,
ZYNQ_QSPI_IDIS_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
complete(&xqspi->data_completion);
}
}
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/**
* zynq_qspi_exec_mem_op() - Initiates the QSPI transfer
* @mem: the SPI memory
* @op: the memory operation to execute
*
* Executes a memory operation.
*
* This function first selects the chip and starts the memory operation.
*
* Return: 0 in case of success, a negative error code otherwise.
*/
static int zynq_qspi_exec_mem_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
struct zynq_qspi *xqspi = spi_controller_get_devdata(mem->spi->master);
int err = 0, i;
u8 *tmpbuf;
dev_dbg(xqspi->dev, "cmd:%#x mode:%d.%d.%d.%d\n",
op->cmd.opcode, op->cmd.buswidth, op->addr.buswidth,
op->dummy.buswidth, op->data.buswidth);
zynq_qspi_chipselect(mem->spi, true);
zynq_qspi_config_op(xqspi, mem->spi);
if (op->cmd.opcode) {
reinit_completion(&xqspi->data_completion);
xqspi->txbuf = (u8 *)&op->cmd.opcode;
xqspi->rxbuf = NULL;
xqspi->tx_bytes = sizeof(op->cmd.opcode);
xqspi->rx_bytes = sizeof(op->cmd.opcode);
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_interruptible_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
}
if (op->addr.nbytes) {
for (i = 0; i < op->addr.nbytes; i++) {
xqspi->txbuf[i] = op->addr.val >>
(8 * (op->addr.nbytes - i - 1));
}
reinit_completion(&xqspi->data_completion);
xqspi->rxbuf = NULL;
xqspi->tx_bytes = op->addr.nbytes;
xqspi->rx_bytes = op->addr.nbytes;
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_interruptible_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
}
if (op->dummy.nbytes) {
tmpbuf = kzalloc(op->dummy.nbytes, GFP_KERNEL);
memset(tmpbuf, 0xff, op->dummy.nbytes);
reinit_completion(&xqspi->data_completion);
xqspi->txbuf = tmpbuf;
xqspi->rxbuf = NULL;
xqspi->tx_bytes = op->dummy.nbytes;
xqspi->rx_bytes = op->dummy.nbytes;
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_interruptible_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
kfree(tmpbuf);
}
if (op->data.nbytes) {
reinit_completion(&xqspi->data_completion);
if (op->data.dir == SPI_MEM_DATA_OUT) {
xqspi->txbuf = (u8 *)op->data.buf.out;
xqspi->tx_bytes = op->data.nbytes;
xqspi->rxbuf = NULL;
xqspi->rx_bytes = op->data.nbytes;
} else {
xqspi->txbuf = NULL;
xqspi->rxbuf = (u8 *)op->data.buf.in;
xqspi->rx_bytes = op->data.nbytes;
xqspi->tx_bytes = op->data.nbytes;
}
zynq_qspi_write_op(xqspi, ZYNQ_QSPI_FIFO_DEPTH, true);
zynq_qspi_write(xqspi, ZYNQ_QSPI_IEN_OFFSET,
ZYNQ_QSPI_IXR_RXTX_MASK);
if (!wait_for_completion_interruptible_timeout(&xqspi->data_completion,
msecs_to_jiffies(1000)))
err = -ETIMEDOUT;
}
zynq_qspi_chipselect(mem->spi, false);
return err;
}
static const struct spi_controller_mem_ops zynq_qspi_mem_ops = {
.supports_op = zynq_qspi_supports_op,
.exec_op = zynq_qspi_exec_mem_op,
};
/**
* zynq_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 zynq_qspi_probe(struct platform_device *pdev)
{
int ret = 0;
struct spi_controller *ctlr;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct zynq_qspi *xqspi;
u32 num_cs;
ctlr = spi_alloc_master(&pdev->dev, sizeof(*xqspi));
if (!ctlr)
return -ENOMEM;
xqspi = spi_controller_get_devdata(ctlr);
xqspi->dev = dev;
platform_set_drvdata(pdev, xqspi);
xqspi->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(xqspi->regs)) {
ret = PTR_ERR(xqspi->regs);
goto remove_master;
}
xqspi->pclk = devm_clk_get(&pdev->dev, "pclk");
if (IS_ERR(xqspi->pclk)) {
dev_err(&pdev->dev, "pclk clock not found.\n");
ret = PTR_ERR(xqspi->pclk);
goto remove_master;
}
init_completion(&xqspi->data_completion);
xqspi->refclk = devm_clk_get(&pdev->dev, "ref_clk");
if (IS_ERR(xqspi->refclk)) {
dev_err(&pdev->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(&pdev->dev, "Unable to enable APB clock.\n");
goto remove_master;
}
ret = clk_prepare_enable(xqspi->refclk);
if (ret) {
dev_err(&pdev->dev, "Unable to enable device clock.\n");
goto clk_dis_pclk;
}
xqspi->irq = platform_get_irq(pdev, 0);
if (xqspi->irq <= 0) {
ret = -ENXIO;
goto remove_master;
}
ret = devm_request_irq(&pdev->dev, xqspi->irq, zynq_qspi_irq,
0, pdev->name, xqspi);
if (ret != 0) {
ret = -ENXIO;
dev_err(&pdev->dev, "request_irq failed\n");
goto remove_master;
}
ret = of_property_read_u32(np, "num-cs",
&num_cs);
if (ret < 0) {
ctlr->num_chipselect = 1;
} else if (num_cs > ZYNQ_QSPI_MAX_NUM_CS) {
dev_err(&pdev->dev, "only 2 chip selects are available\n");
goto remove_master;
} else {
ctlr->num_chipselect = num_cs;
}
ctlr->mode_bits = SPI_RX_DUAL | SPI_RX_QUAD |
SPI_TX_DUAL | SPI_TX_QUAD;
ctlr->mem_ops = &zynq_qspi_mem_ops;
ctlr->setup = zynq_qspi_setup_op;
ctlr->max_speed_hz = clk_get_rate(xqspi->refclk) / 2;
ctlr->dev.of_node = np;
/* QSPI controller initializations */
zynq_qspi_init_hw(xqspi, ctlr->num_chipselect);
ret = devm_spi_register_controller(&pdev->dev, ctlr);
if (ret) {
dev_err(&pdev->dev, "spi_register_master failed\n");
goto clk_dis_all;
}
return ret;
clk_dis_all:
clk_disable_unprepare(xqspi->refclk);
clk_dis_pclk:
clk_disable_unprepare(xqspi->pclk);
remove_master:
spi_controller_put(ctlr);
return ret;
}
/**
* zynq_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 on success and error value on failure
*/
static int zynq_qspi_remove(struct platform_device *pdev)
{
struct zynq_qspi *xqspi = platform_get_drvdata(pdev);
zynq_qspi_write(xqspi, ZYNQ_QSPI_ENABLE_OFFSET, 0);
clk_disable_unprepare(xqspi->refclk);
clk_disable_unprepare(xqspi->pclk);
return 0;
}
static const struct of_device_id zynq_qspi_of_match[] = {
{ .compatible = "xlnx,zynq-qspi-1.0", },
{ /* end of table */ }
};
MODULE_DEVICE_TABLE(of, zynq_qspi_of_match);
/*
* zynq_qspi_driver - This structure defines the QSPI platform driver
*/
static struct platform_driver zynq_qspi_driver = {
.probe = zynq_qspi_probe,
.remove = zynq_qspi_remove,
.driver = {
.name = "zynq-qspi",
.of_match_table = zynq_qspi_of_match,
},
};
module_platform_driver(zynq_qspi_driver);
MODULE_AUTHOR("Xilinx, Inc.");
MODULE_DESCRIPTION("Xilinx Zynq QSPI driver");
MODULE_LICENSE("GPL");