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Diffstat (limited to '')
| -rw-r--r-- | drivers/spi/spi-zynq-qspi.c | 779 |
1 files changed, 779 insertions, 0 deletions
diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c new file mode 100644 index 000000000..13c0b15fe --- /dev/null +++ b/drivers/spi/spi-zynq-qspi.c @@ -0,0 +1,779 @@ +// 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 + * @dev: Pointer to the this device's information + * @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 + * @spi: 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 = op->cmd.nbytes; + xqspi->rx_bytes = op->cmd.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_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_timeout(&xqspi->data_completion, + msecs_to_jiffies(1000))) + err = -ETIMEDOUT; + } + + if (op->dummy.nbytes) { + tmpbuf = kzalloc(op->dummy.nbytes, GFP_KERNEL); + if (!tmpbuf) + return -ENOMEM; + + 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_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_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 clk_dis_all; + } + 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 clk_dis_all; + } + + 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) { + ret = -EINVAL; + dev_err(&pdev->dev, "only 2 chip selects are available\n"); + goto clk_dis_all; + } 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"); |