[PATCH v2 3/4] spi: Add Microchip PolarFire SoC QSPI driver

Padmarao Begari
2022-10-21T07:01:17Z

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@microchip.com>
Signed-off-by: Naga Sureshkumar Relli <nagasuresh.relli@microchip.com>
Signed-off-by: Padmarao Begari <padmarao.begari@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..ea81ddd03c
--- /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@microchip.com>
+ * Naga Sureshkumar Relli <nagasuresh.relli@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 * 60)
+
+/*
+ * 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