--- /dev/null
+// SPDX-License-Identifier: (GPL-2.0)
+/*
+ * Microchip coreQSPI QSPI controller driver
+ *
+ * Copyright (C) 2018-2022 Microchip Technology Inc. and its subsidiaries
+ *
+ * Author: Naga Sureshkumar Relli <nagasuresh.relli@microchip.com>
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+
+/*
+ * QSPI Control register mask defines
+ */
+#define CONTROL_ENABLE BIT(0)
+#define CONTROL_MASTER BIT(1)
+#define CONTROL_XIP BIT(2)
+#define CONTROL_XIPADDR BIT(3)
+#define CONTROL_CLKIDLE BIT(10)
+#define CONTROL_SAMPLE_MASK GENMASK(12, 11)
+#define CONTROL_MODE0 BIT(13)
+#define CONTROL_MODE12_MASK GENMASK(15, 14)
+#define CONTROL_MODE12_EX_RO BIT(14)
+#define CONTROL_MODE12_EX_RW BIT(15)
+#define CONTROL_MODE12_FULL GENMASK(15, 14)
+#define CONTROL_FLAGSX4 BIT(16)
+#define CONTROL_CLKRATE_MASK GENMASK(27, 24)
+#define CONTROL_CLKRATE_SHIFT 24
+
+/*
+ * QSPI Frames register mask defines
+ */
+#define FRAMES_TOTALBYTES_MASK GENMASK(15, 0)
+#define FRAMES_CMDBYTES_MASK GENMASK(24, 16)
+#define FRAMES_CMDBYTES_SHIFT 16
+#define FRAMES_SHIFT 25
+#define FRAMES_IDLE_MASK GENMASK(29, 26)
+#define FRAMES_IDLE_SHIFT 26
+#define FRAMES_FLAGBYTE BIT(30)
+#define FRAMES_FLAGWORD BIT(31)
+
+/*
+ * QSPI Interrupt Enable register mask defines
+ */
+#define IEN_TXDONE BIT(0)
+#define IEN_RXDONE BIT(1)
+#define IEN_RXAVAILABLE BIT(2)
+#define IEN_TXAVAILABLE BIT(3)
+#define IEN_RXFIFOEMPTY BIT(4)
+#define IEN_TXFIFOFULL BIT(5)
+
+/*
+ * QSPI Status register mask defines
+ */
+#define STATUS_TXDONE BIT(0)
+#define STATUS_RXDONE BIT(1)
+#define STATUS_RXAVAILABLE BIT(2)
+#define STATUS_TXAVAILABLE BIT(3)
+#define STATUS_RXFIFOEMPTY BIT(4)
+#define STATUS_TXFIFOFULL BIT(5)
+#define STATUS_READY BIT(7)
+#define STATUS_FLAGSX4 BIT(8)
+#define STATUS_MASK GENMASK(8, 0)
+
+#define BYTESUPPER_MASK GENMASK(31, 16)
+#define BYTESLOWER_MASK GENMASK(15, 0)
+
+#define MAX_DIVIDER 16
+#define MIN_DIVIDER 0
+#define MAX_DATA_CMD_LEN 256
+
+/* QSPI ready time out value */
+#define TIMEOUT_MS 500
+
+/*
+ * QSPI Register offsets.
+ */
+#define REG_CONTROL (0x00)
+#define REG_FRAMES (0x04)
+#define REG_IEN (0x0c)
+#define REG_STATUS (0x10)
+#define REG_DIRECT_ACCESS (0x14)
+#define REG_UPPER_ACCESS (0x18)
+#define REG_RX_DATA (0x40)
+#define REG_TX_DATA (0x44)
+#define REG_X4_RX_DATA (0x48)
+#define REG_X4_TX_DATA (0x4c)
+#define REG_FRAMESUP (0x50)
+
+/**
+ * struct mchp_coreqspi - Defines qspi driver instance
+ * @regs: Virtual address of the QSPI controller registers
+ * @clk: QSPI Operating clock
+ * @data_completion: completion structure
+ * @op_lock: lock access to the device
+ * @txbuf: TX buffer
+ * @rxbuf: RX buffer
+ * @irq: IRQ number
+ * @tx_len: Number of bytes left to transfer
+ * @rx_len: Number of bytes left to receive
+ */
+struct mchp_coreqspi {
+ void __iomem *regs;
+ struct clk *clk;
+ struct completion data_completion;
+ struct mutex op_lock; /* lock access to the device */
+ u8 *txbuf;
+ u8 *rxbuf;
+ int irq;
+ int tx_len;
+ int rx_len;
+};
+
+static int mchp_coreqspi_set_mode(struct mchp_coreqspi *qspi, const struct spi_mem_op *op)
+{
+ u32 control = readl_relaxed(qspi->regs + REG_CONTROL);
+
+ /*
+ * The operating mode can be configured based on the command that needs to be send.
+ * bits[15:14]: Sets whether multiple bit SPI operates in normal, extended or full modes.
+ * 00: Normal (single DQ0 TX and single DQ1 RX lines)
+ * 01: Extended RO (command and address bytes on DQ0 only)
+ * 10: Extended RW (command byte on DQ0 only)
+ * 11: Full. (command and address are on all DQ lines)
+ * bit[13]: Sets whether multiple bit SPI uses 2 or 4 bits of data
+ * 0: 2-bits (BSPI)
+ * 1: 4-bits (QSPI)
+ */
+ if (op->data.buswidth == 4 || op->data.buswidth == 2) {
+ control &= ~CONTROL_MODE12_MASK;
+ if (op->cmd.buswidth == 1 && (op->addr.buswidth == 1 || op->addr.buswidth == 0))
+ control |= CONTROL_MODE12_EX_RO;
+ else if (op->cmd.buswidth == 1)
+ control |= CONTROL_MODE12_EX_RW;
+ else
+ control |= CONTROL_MODE12_FULL;
+
+ control |= CONTROL_MODE0;
+ } else {
+ control &= ~(CONTROL_MODE12_MASK |
+ CONTROL_MODE0);
+ }
+
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+
+ return 0;
+}
+
+static inline void mchp_coreqspi_read_op(struct mchp_coreqspi *qspi)
+{
+ u32 control, data;
+
+ if (!qspi->rx_len)
+ return;
+
+ control = readl_relaxed(qspi->regs + REG_CONTROL);
+
+ /*
+ * Read 4-bytes from the SPI FIFO in single transaction and then read
+ * the reamaining data byte wise.
+ */
+ control |= CONTROL_FLAGSX4;
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+
+ while (qspi->rx_len >= 4) {
+ while (readl_relaxed(qspi->regs + REG_STATUS) & STATUS_RXFIFOEMPTY)
+ ;
+ data = readl_relaxed(qspi->regs + REG_X4_RX_DATA);
+ *(u32 *)qspi->rxbuf = data;
+ qspi->rxbuf += 4;
+ qspi->rx_len -= 4;
+ }
+
+ control &= ~CONTROL_FLAGSX4;
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+
+ while (qspi->rx_len--) {
+ while (readl_relaxed(qspi->regs + REG_STATUS) & STATUS_RXFIFOEMPTY)
+ ;
+ data = readl_relaxed(qspi->regs + REG_RX_DATA);
+ *qspi->rxbuf++ = (data & 0xFF);
+ }
+}
+
+static inline void mchp_coreqspi_write_op(struct mchp_coreqspi *qspi, bool word)
+{
+ u32 control, data;
+
+ control = readl_relaxed(qspi->regs + REG_CONTROL);
+ control |= CONTROL_FLAGSX4;
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+
+ while (qspi->tx_len >= 4) {
+ while (readl_relaxed(qspi->regs + REG_STATUS) & STATUS_TXFIFOFULL)
+ ;
+ data = *(u32 *)qspi->txbuf;
+ qspi->txbuf += 4;
+ qspi->tx_len -= 4;
+ writel_relaxed(data, qspi->regs + REG_X4_TX_DATA);
+ }
+
+ control &= ~CONTROL_FLAGSX4;
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+
+ while (qspi->tx_len--) {
+ while (readl_relaxed(qspi->regs + REG_STATUS) & STATUS_TXFIFOFULL)
+ ;
+ data = *qspi->txbuf++;
+ writel_relaxed(data, qspi->regs + REG_TX_DATA);
+ }
+}
+
+static void mchp_coreqspi_enable_ints(struct mchp_coreqspi *qspi)
+{
+ u32 mask = IEN_TXDONE |
+ IEN_RXDONE |
+ IEN_RXAVAILABLE;
+
+ writel_relaxed(mask, qspi->regs + REG_IEN);
+}
+
+static void mchp_coreqspi_disable_ints(struct mchp_coreqspi *qspi)
+{
+ writel_relaxed(0, qspi->regs + REG_IEN);
+}
+
+static irqreturn_t mchp_coreqspi_isr(int irq, void *dev_id)
+{
+ struct mchp_coreqspi *qspi = (struct mchp_coreqspi *)dev_id;
+ irqreturn_t ret = IRQ_NONE;
+ int intfield = readl_relaxed(qspi->regs + REG_STATUS) & STATUS_MASK;
+
+ if (intfield == 0)
+ return ret;
+
+ if (intfield & IEN_TXDONE) {
+ writel_relaxed(IEN_TXDONE, qspi->regs + REG_STATUS);
+ ret = IRQ_HANDLED;
+ }
+
+ if (intfield & IEN_RXAVAILABLE) {
+ writel_relaxed(IEN_RXAVAILABLE, qspi->regs + REG_STATUS);
+ mchp_coreqspi_read_op(qspi);
+ ret = IRQ_HANDLED;
+ }
+
+ if (intfield & IEN_RXDONE) {
+ writel_relaxed(IEN_RXDONE, qspi->regs + REG_STATUS);
+ complete(&qspi->data_completion);
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static int mchp_coreqspi_setup_clock(struct mchp_coreqspi *qspi, struct spi_device *spi)
+{
+ unsigned long clk_hz;
+ u32 control, baud_rate_val = 0;
+
+ clk_hz = clk_get_rate(qspi->clk);
+ if (!clk_hz)
+ return -EINVAL;
+
+ baud_rate_val = DIV_ROUND_UP(clk_hz, 2 * spi->max_speed_hz);
+ if (baud_rate_val > MAX_DIVIDER || baud_rate_val < MIN_DIVIDER) {
+ dev_err(&spi->dev,
+ "could not configure the clock for spi clock %d Hz & system clock %ld Hz\n",
+ spi->max_speed_hz, clk_hz);
+ return -EINVAL;
+ }
+
+ control = readl_relaxed(qspi->regs + REG_CONTROL);
+ control |= baud_rate_val << CONTROL_CLKRATE_SHIFT;
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+ control = readl_relaxed(qspi->regs + REG_CONTROL);
+
+ if ((spi->mode & SPI_CPOL) && (spi->mode & SPI_CPHA))
+ control |= CONTROL_CLKIDLE;
+ else
+ control &= ~CONTROL_CLKIDLE;
+
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+
+ return 0;
+}
+
+static int mchp_coreqspi_setup_op(struct spi_device *spi_dev)
+{
+ struct spi_controller *ctlr = spi_dev->master;
+ struct mchp_coreqspi *qspi = spi_controller_get_devdata(ctlr);
+ u32 control = readl_relaxed(qspi->regs + REG_CONTROL);
+
+ control |= (CONTROL_MASTER | CONTROL_ENABLE);
+ control &= ~CONTROL_CLKIDLE;
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+
+ return 0;
+}
+
+static inline void mchp_coreqspi_config_op(struct mchp_coreqspi *qspi, const struct spi_mem_op *op)
+{
+ u32 idle_cycles = 0;
+ int total_bytes, cmd_bytes, frames, ctrl;
+
+ cmd_bytes = op->cmd.nbytes + op->addr.nbytes;
+ total_bytes = cmd_bytes + op->data.nbytes;
+
+ /*
+ * As per the coreQSPI IP spec,the number of command and data bytes are
+ * controlled by the frames register for each SPI sequence. This supports
+ * the SPI flash memory read and writes sequences as below. so configure
+ * the cmd and total bytes accordingly.
+ * ---------------------------------------------------------------------
+ * TOTAL BYTES | CMD BYTES | What happens |
+ * ______________________________________________________________________
+ * | | |
+ * 1 | 1 | The SPI core will transmit a single byte |
+ * | | and receive data is discarded |
+ * | | |
+ * 1 | 0 | The SPI core will transmit a single byte |
+ * | | and return a single byte |
+ * | | |
+ * 10 | 4 | The SPI core will transmit 4 command |
+ * | | bytes discarding the receive data and |
+ * | | transmits 6 dummy bytes returning the 6 |
+ * | | received bytes and return a single byte |
+ * | | |
+ * 10 | 10 | The SPI core will transmit 10 command |
+ * | | |
+ * 10 | 0 | The SPI core will transmit 10 command |
+ * | | bytes and returning 10 received bytes |
+ * ______________________________________________________________________
+ */
+ if (!(op->data.dir == SPI_MEM_DATA_IN))
+ cmd_bytes = total_bytes;
+
+ frames = total_bytes & BYTESUPPER_MASK;
+ writel_relaxed(frames, qspi->regs + REG_FRAMESUP);
+ frames = total_bytes & BYTESLOWER_MASK;
+ frames |= cmd_bytes << FRAMES_CMDBYTES_SHIFT;
+
+ if (op->dummy.buswidth)
+ idle_cycles = op->dummy.nbytes * 8 / op->dummy.buswidth;
+
+ frames |= idle_cycles << FRAMES_IDLE_SHIFT;
+ ctrl = readl_relaxed(qspi->regs + REG_CONTROL);
+
+ if (ctrl & CONTROL_MODE12_MASK)
+ frames |= (1 << FRAMES_SHIFT);
+
+ frames |= FRAMES_FLAGWORD;
+ writel_relaxed(frames, qspi->regs + REG_FRAMES);
+}
+
+static int mchp_qspi_wait_for_ready(struct spi_mem *mem)
+{
+ struct mchp_coreqspi *qspi = spi_controller_get_devdata
+ (mem->spi->master);
+ u32 status;
+ int ret;
+
+ ret = readl_poll_timeout(qspi->regs + REG_STATUS, status,
+ (status & STATUS_READY), 0,
+ TIMEOUT_MS);
+ if (ret) {
+ dev_err(&mem->spi->dev,
+ "Timeout waiting on QSPI ready.\n");
+ return -ETIMEDOUT;
+ }
+
+ return ret;
+}
+
+static int mchp_coreqspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ struct mchp_coreqspi *qspi = spi_controller_get_devdata
+ (mem->spi->master);
+ u32 address = op->addr.val;
+ u8 opcode = op->cmd.opcode;
+ u8 opaddr[5];
+ int err, i;
+
+ mutex_lock(&qspi->op_lock);
+ err = mchp_qspi_wait_for_ready(mem);
+ if (err)
+ goto error;
+
+ err = mchp_coreqspi_setup_clock(qspi, mem->spi);
+ if (err)
+ goto error;
+
+ err = mchp_coreqspi_set_mode(qspi, op);
+ if (err)
+ goto error;
+
+ reinit_completion(&qspi->data_completion);
+ mchp_coreqspi_config_op(qspi, op);
+ if (op->cmd.opcode) {
+ qspi->txbuf = &opcode;
+ qspi->rxbuf = NULL;
+ qspi->tx_len = op->cmd.nbytes;
+ qspi->rx_len = 0;
+ mchp_coreqspi_write_op(qspi, false);
+ }
+
+ qspi->txbuf = &opaddr[0];
+ if (op->addr.nbytes) {
+ for (i = 0; i < op->addr.nbytes; i++)
+ qspi->txbuf[i] = address >> (8 * (op->addr.nbytes - i - 1));
+
+ qspi->rxbuf = NULL;
+ qspi->tx_len = op->addr.nbytes;
+ qspi->rx_len = 0;
+ mchp_coreqspi_write_op(qspi, false);
+ }
+
+ if (op->data.nbytes) {
+ if (op->data.dir == SPI_MEM_DATA_OUT) {
+ qspi->txbuf = (u8 *)op->data.buf.out;
+ qspi->rxbuf = NULL;
+ qspi->rx_len = 0;
+ qspi->tx_len = op->data.nbytes;
+ mchp_coreqspi_write_op(qspi, true);
+ } else {
+ qspi->txbuf = NULL;
+ qspi->rxbuf = (u8 *)op->data.buf.in;
+ qspi->rx_len = op->data.nbytes;
+ qspi->tx_len = 0;
+ }
+ }
+
+ mchp_coreqspi_enable_ints(qspi);
+
+ if (!wait_for_completion_timeout(&qspi->data_completion, msecs_to_jiffies(1000)))
+ err = -ETIMEDOUT;
+
+error:
+ mutex_unlock(&qspi->op_lock);
+ mchp_coreqspi_disable_ints(qspi);
+
+ return err;
+}
+
+static bool mchp_coreqspi_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+ if (!spi_mem_default_supports_op(mem, op))
+ return false;
+
+ if ((op->data.buswidth == 4 || op->data.buswidth == 2) &&
+ (op->cmd.buswidth == 1 && (op->addr.buswidth == 1 || op->addr.buswidth == 0))) {
+ /*
+ * If the command and address are on DQ0 only, then this
+ * controller doesn't support sending data on dual and
+ * quad lines. but it supports reading data on dual and
+ * quad lines with same configuration as command and
+ * address on DQ0.
+ * i.e. The control register[15:13] :EX_RO(read only) is
+ * meant only for the command and address are on DQ0 but
+ * not to write data, it is just to read.
+ * Ex: 0x34h is Quad Load Program Data which is not
+ * supported. Then the spi-mem layer will iterate over
+ * each command and it will chose the supported one.
+ */
+ if (op->data.dir == SPI_MEM_DATA_OUT)
+ return false;
+ }
+
+ return true;
+}
+
+static int mchp_coreqspi_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
+{
+ if (op->data.dir == SPI_MEM_DATA_OUT || op->data.dir == SPI_MEM_DATA_IN) {
+ if (op->data.nbytes > MAX_DATA_CMD_LEN)
+ op->data.nbytes = MAX_DATA_CMD_LEN;
+ }
+
+ return 0;
+}
+
+static const struct spi_controller_mem_ops mchp_coreqspi_mem_ops = {
+ .adjust_op_size = mchp_coreqspi_adjust_op_size,
+ .supports_op = mchp_coreqspi_supports_op,
+ .exec_op = mchp_coreqspi_exec_op,
+};
+
+static int mchp_coreqspi_probe(struct platform_device *pdev)
+{
+ struct spi_controller *ctlr;
+ struct mchp_coreqspi *qspi;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ int ret;
+
+ ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*qspi));
+ if (!ctlr)
+ return dev_err_probe(&pdev->dev, -ENOMEM,
+ "unable to allocate master for QSPI controller\n");
+
+ qspi = spi_controller_get_devdata(ctlr);
+ platform_set_drvdata(pdev, qspi);
+
+ qspi->regs = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(qspi->regs))
+ return dev_err_probe(&pdev->dev, PTR_ERR(qspi->regs),
+ "failed to map registers\n");
+
+ qspi->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(qspi->clk))
+ return dev_err_probe(&pdev->dev, PTR_ERR(qspi->clk),
+ "could not get clock\n");
+
+ ret = clk_prepare_enable(qspi->clk);
+ if (ret)
+ return dev_err_probe(&pdev->dev, ret,
+ "failed to enable clock\n");
+
+ init_completion(&qspi->data_completion);
+ mutex_init(&qspi->op_lock);
+
+ qspi->irq = platform_get_irq(pdev, 0);
+ if (qspi->irq < 0) {
+ ret = qspi->irq;
+ goto out;
+ }
+
+ ret = devm_request_irq(&pdev->dev, qspi->irq, mchp_coreqspi_isr,
+ IRQF_SHARED, pdev->name, qspi);
+ if (ret) {
+ dev_err(&pdev->dev, "request_irq failed %d\n", ret);
+ goto out;
+ }
+
+ ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
+ ctlr->mem_ops = &mchp_coreqspi_mem_ops;
+ ctlr->setup = mchp_coreqspi_setup_op;
+ ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_RX_DUAL | SPI_RX_QUAD |
+ SPI_TX_DUAL | SPI_TX_QUAD;
+ ctlr->dev.of_node = np;
+
+ ret = devm_spi_register_controller(&pdev->dev, ctlr);
+ if (ret) {
+ dev_err_probe(&pdev->dev, ret,
+ "spi_register_controller failed\n");
+ goto out;
+ }
+
+ return 0;
+
+out:
+ clk_disable_unprepare(qspi->clk);
+
+ return ret;
+}
+
+static int mchp_coreqspi_remove(struct platform_device *pdev)
+{
+ struct mchp_coreqspi *qspi = platform_get_drvdata(pdev);
+ u32 control = readl_relaxed(qspi->regs + REG_CONTROL);
+
+ mchp_coreqspi_disable_ints(qspi);
+ control &= ~CONTROL_ENABLE;
+ writel_relaxed(control, qspi->regs + REG_CONTROL);
+ clk_disable_unprepare(qspi->clk);
+
+ return 0;
+}
+
+static const struct of_device_id mchp_coreqspi_of_match[] = {
+ { .compatible = "microchip,coreqspi-rtl-v2" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mchp_coreqspi_of_match);
+
+static struct platform_driver mchp_coreqspi_driver = {
+ .probe = mchp_coreqspi_probe,
+ .driver = {
+ .name = "microchip,coreqspi",
+ .of_match_table = mchp_coreqspi_of_match,
+ },
+ .remove = mchp_coreqspi_remove,
+};
+module_platform_driver(mchp_coreqspi_driver);
+
+MODULE_AUTHOR("Naga Sureshkumar Relli <nagasuresh.relli@microchip.com");
+MODULE_DESCRIPTION("Microchip coreQSPI QSPI controller driver");
+MODULE_LICENSE("GPL");
projects / linux.git / commitdiff