[PATCH v3 3/4] spi: Add Microchip PolarFire SoC QSPI driver

Padmarao Begari padmarao.begari at microchip.com
Thu Oct 27 08:02:01 CEST 2022


Add QSPI driver code for the Microchip PolarFire SoC.
This driver supports the QSPI standard, dual and quad
mode interfaces.

Co-developed-by: Naga Sureshkumar Relli <nagasuresh.relli at microchip.com>
Signed-off-by: Naga Sureshkumar Relli <nagasuresh.relli at microchip.com>
Signed-off-by: Padmarao Begari <padmarao.begari at microchip.com>
Reviewed-by: Conor Dooley <conor.dooley at microchip.com>
---
 drivers/spi/Kconfig              |   6 +
 drivers/spi/Makefile             |   1 +
 drivers/spi/microchip_coreqspi.c | 505 +++++++++++++++++++++++++++++++
 3 files changed, 512 insertions(+)
 create mode 100644 drivers/spi/microchip_coreqspi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 2f12081f88..994bfd563e 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -237,6 +237,12 @@ config MESON_SPIFC
 	  This driver can be used to access the SPI NOR flash chips on
 	  Amlogic Meson SoCs.
 
+config MICROCHIP_COREQSPI
+	bool "Microchip FPGA QSPI Controller driver"
+	help
+	  Enable the QSPI driver for Microchip FPGA QSPI controllers.
+	  This driver can be used on Polarfire SoC.
+
 config MPC8XX_SPI
 	bool "MPC8XX SPI Driver"
 	depends on MPC8xx
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 50ba43550b..6d1154b902 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_ICH_SPI) +=  ich.o
 obj-$(CONFIG_IPROC_QSPI) += iproc_qspi.o
 obj-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
 obj-$(CONFIG_MESON_SPIFC) += meson_spifc.o
+obj-$(CONFIG_MICROCHIP_COREQSPI) += microchip_coreqspi.o
 obj-$(CONFIG_MPC8XX_SPI) += mpc8xx_spi.o
 obj-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 obj-$(CONFIG_MTK_SNFI_SPI) += mtk_snfi_spi.o
diff --git a/drivers/spi/microchip_coreqspi.c b/drivers/spi/microchip_coreqspi.c
new file mode 100644
index 0000000000..5fe0c8e123
--- /dev/null
+++ b/drivers/spi/microchip_coreqspi.c
@@ -0,0 +1,505 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 Microchip Technology Inc.
+ * Padmarao Begari <padmarao.begari at microchip.com>
+ * Naga Sureshkumar Relli <nagasuresh.relli at microchip.com>
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <log.h>
+#include <malloc.h>
+#include <spi.h>
+#include <spi-mem.h>
+#include <asm/io.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/sizes.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/*
+ * 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             (1000 * 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:              Address of the QSPI controller registers
+ * @freq:              QSPI Input frequency
+ * @txbuf:             TX buffer
+ * @rxbuf:             RX buffer
+ * @tx_len:            Number of bytes left to transfer
+ * @rx_len:            Number of bytes left to receive
+ */
+struct mchp_coreqspi {
+	void __iomem *regs;
+	u32 freq;
+	u8 *txbuf;
+	u8 *rxbuf;
+	int tx_len;
+	int rx_len;
+};
+
+static void mchp_coreqspi_init_hw(struct mchp_coreqspi *qspi)
+{
+	u32 control;
+
+	control = CONTROL_CLKIDLE | CONTROL_ENABLE;
+
+	writel(control, qspi->regs + REG_CONTROL);
+	writel(0, qspi->regs + REG_IEN);
+}
+
+static inline void mchp_coreqspi_read_op(struct mchp_coreqspi *qspi)
+{
+	u32 control, data;
+
+	if (!qspi->rx_len)
+		return;
+
+	control = readl(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(control, qspi->regs + REG_CONTROL);
+
+	while (qspi->rx_len >= 4) {
+		while (readl(qspi->regs + REG_STATUS) & STATUS_RXFIFOEMPTY)
+			;
+		data = readl(qspi->regs + REG_X4_RX_DATA);
+		*(u32 *)qspi->rxbuf = data;
+		qspi->rxbuf += 4;
+		qspi->rx_len -= 4;
+	}
+
+	control &= ~CONTROL_FLAGSX4;
+	writel(control, qspi->regs + REG_CONTROL);
+
+	while (qspi->rx_len--) {
+		while (readl(qspi->regs + REG_STATUS) & STATUS_RXFIFOEMPTY)
+			;
+		data = readl(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(qspi->regs + REG_CONTROL);
+	control |= CONTROL_FLAGSX4;
+	writel(control, qspi->regs + REG_CONTROL);
+
+	while (qspi->tx_len >= 4) {
+		while (readl(qspi->regs + REG_STATUS) & STATUS_TXFIFOFULL)
+			;
+		data = *(u32 *)qspi->txbuf;
+		qspi->txbuf += 4;
+		qspi->tx_len -= 4;
+		writel(data, qspi->regs + REG_X4_TX_DATA);
+	}
+
+	control &= ~CONTROL_FLAGSX4;
+	writel(control, qspi->regs + REG_CONTROL);
+
+	while (qspi->tx_len--) {
+		while (readl(qspi->regs + REG_STATUS) & STATUS_TXFIFOFULL)
+			;
+		data =  *qspi->txbuf++;
+		writel(data, qspi->regs + REG_TX_DATA);
+	}
+}
+
+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(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(qspi->regs + REG_CONTROL);
+
+	if (ctrl & CONTROL_MODE12_MASK)
+		frames |= (1 << FRAMES_SHIFT);
+
+	frames |= FRAMES_FLAGWORD;
+	writel(frames, qspi->regs + REG_FRAMES);
+}
+
+static int mchp_coreqspi_wait_for_ready(struct spi_slave *slave)
+{
+	struct mchp_coreqspi *qspi = dev_get_priv(slave->dev->parent);
+	unsigned long count = 0;
+
+	while (1) {
+		if (readl(qspi->regs + REG_STATUS) & STATUS_READY)
+			return 0;
+
+		udelay(1);
+		count += 1;
+		if (count == TIMEOUT_MS)
+			return -ETIMEDOUT;
+	}
+}
+
+static int mchp_coreqspi_set_operate_mode(struct mchp_coreqspi *qspi,
+					  const struct spi_mem_op *op)
+{
+	u32 control = readl(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(control, qspi->regs + REG_CONTROL);
+
+	return 0;
+}
+
+static int mchp_coreqspi_exec_op(struct spi_slave *slave,
+				 const struct spi_mem_op *op)
+{
+	struct mchp_coreqspi *qspi = dev_get_priv(slave->dev->parent);
+
+	u32 address = op->addr.val;
+	u8 opcode = op->cmd.opcode;
+	u8 opaddr[5];
+	int err = 0, i;
+
+	err = mchp_coreqspi_wait_for_ready(slave);
+	if (err)
+		return err;
+
+	err = mchp_coreqspi_set_operate_mode(qspi, op);
+	if (err)
+		return err;
+
+	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_read_op(qspi);
+		}
+	}
+
+	return 0;
+}
+
+static bool mchp_coreqspi_supports_op(struct spi_slave *slave,
+				      const struct spi_mem_op *op)
+{
+	if (!spi_mem_default_supports_op(slave, 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_slave *slave,
+					struct spi_mem_op *op)
+{
+	if (op->data.dir == SPI_MEM_DATA_OUT) {
+		if (op->data.nbytes > MAX_DATA_CMD_LEN)
+			op->data.nbytes = MAX_DATA_CMD_LEN;
+	}
+
+	return 0;
+}
+
+static int mchp_coreqspi_set_speed(struct udevice *dev, uint speed)
+{
+	struct mchp_coreqspi *qspi = dev_get_priv(dev);
+	u32 control, baud_rate_val = 0;
+
+	if (speed > (qspi->freq / 2))
+		speed = qspi->freq / 2;
+
+	baud_rate_val = DIV_ROUND_UP(qspi->freq, 2 * speed);
+	if (baud_rate_val >= MAX_DIVIDER || baud_rate_val <= MIN_DIVIDER)
+		return -EINVAL;
+
+	control = readl(qspi->regs + REG_CONTROL);
+	control &= ~CONTROL_CLKRATE_MASK;
+	control |= baud_rate_val << CONTROL_CLKRATE_SHIFT;
+	writel(control, qspi->regs + REG_CONTROL);
+
+	return 0;
+}
+
+static int mchp_coreqspi_set_mode(struct udevice *dev, uint mode)
+{
+	struct mchp_coreqspi *qspi = dev_get_priv(dev);
+	u32 control;
+
+	control = readl(qspi->regs + REG_CONTROL);
+
+	if ((mode & SPI_CPOL) && (mode & SPI_CPHA))
+		control |= CONTROL_CLKIDLE;
+	else
+		control &= ~CONTROL_CLKIDLE;
+
+	writel(control, qspi->regs + REG_CONTROL);
+
+	return 0;
+}
+
+static int mchp_coreqspi_claim_bus(struct udevice *dev)
+{
+	return 0;
+}
+
+static int mchp_coreqspi_release_bus(struct udevice *dev)
+{
+	return 0;
+}
+
+static int mchp_coreqspi_probe(struct udevice *dev)
+{
+	struct mchp_coreqspi *qspi = dev_get_priv(dev);
+	struct clk clk;
+	ulong clk_rate;
+	int ret;
+
+	ret = clk_get_by_index(dev, 0, &clk);
+	if (ret)
+		return -EINVAL;
+
+	ret = clk_enable(&clk);
+	if (ret)
+		return ret;
+
+	clk_rate = clk_get_rate(&clk);
+	if (!clk_rate)
+		return -EINVAL;
+	qspi->freq = clk_rate;
+
+	qspi->regs = dev_read_addr_ptr(dev);
+	if (!qspi->regs)
+		return -EINVAL;
+
+	/* Init the mpfs qspi hw */
+	mchp_coreqspi_init_hw(qspi);
+
+	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 const struct dm_spi_ops mchp_coreqspi_ops = {
+	.claim_bus      = mchp_coreqspi_claim_bus,
+	.release_bus    = mchp_coreqspi_release_bus,
+	.set_speed      = mchp_coreqspi_set_speed,
+	.set_mode       = mchp_coreqspi_set_mode,
+	.mem_ops        = &mchp_coreqspi_mem_ops,
+};
+
+static const struct udevice_id mchp_coreqspi_ids[] = {
+	{ .compatible = "microchip,mpfs-coreqspi-rtl-v2" },
+	{ .compatible = "microchip,mpfs-qspi" },
+	{ }
+};
+
+U_BOOT_DRIVER(mchp_coreqspi) = {
+	.name   = "mchp_coreqspi",
+	.id     = UCLASS_SPI,
+	.of_match = mchp_coreqspi_ids,
+	.ops    = &mchp_coreqspi_ops,
+	.priv_auto = sizeof(struct mchp_coreqspi),
+	.probe  = mchp_coreqspi_probe,
+};
-- 
2.25.1



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