[PATCH 5/5] mtd: spi-nor: Add Synopsys DesignWare Octal SPI driver
Jules Maselbas
jmaselbas at kalray.eu
Mon Jul 17 09:54:28 PDT 2023
Signed-off-by: Jules Maselbas <jmaselbas at kalray.eu>
---
drivers/mtd/spi-nor/Kconfig | 6 +
drivers/mtd/spi-nor/Makefile | 1 +
drivers/mtd/spi-nor/dw-ospi-nor.c | 960 ++++++++++++++++++++++++++++++
3 files changed, 967 insertions(+)
create mode 100644 drivers/mtd/spi-nor/dw-ospi-nor.c
diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 2beb26006e..b34c69203e 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -26,4 +26,10 @@ config SPI_CADENCE_QUADSPI
help
This enables support for the Cadence Quad SPI controller and NOR flash.
+config SPI_SYNOPSYS_OCTALSPI_NOR
+ tristate "Synopsys DesignWare Octal SPI controller"
+ help
+ This enables support for the Synopsys DesignWare Octal SPI controller
+ and NOR flash.
+
endif
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
index 457a2f0488..61cf789182 100644
--- a/drivers/mtd/spi-nor/Makefile
+++ b/drivers/mtd/spi-nor/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_MTD_SPI_NOR) += spi-nor.o
obj-$(CONFIG_SPI_CADENCE_QUADSPI) += cadence-quadspi.o
+obj-$(CONFIG_SPI_SYNOPSYS_OCTALSPI_NOR) += dw-ospi-nor.o
diff --git a/drivers/mtd/spi-nor/dw-ospi-nor.c b/drivers/mtd/spi-nor/dw-ospi-nor.c
new file mode 100644
index 0000000000..13033f9500
--- /dev/null
+++ b/drivers/mtd/spi-nor/dw-ospi-nor.c
@@ -0,0 +1,960 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// SPDX-FileCopyrightText: 2018 Vincent Chardon, Kalray Inc.
+// SPDX-FileCopyrightText: 2023 Jules Maselbas, Kalray Inc.
+
+#include <clock.h>
+#include <common.h>
+#include <driver.h>
+#include <errno.h>
+#include <init.h>
+#include <io.h>
+#include <linux/clk.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/spi-nor.h>
+#include <of.h>
+#include <spi/spi.h>
+
+/* Register offsets */
+#define DW_SPI_CTRL0 0x00
+#define DW_SPI_CTRL1 0x04
+#define DW_SPI_SSIENR 0x08
+#define DW_SPI_MWCR 0x0c
+#define DW_SPI_SER 0x10
+#define DW_SPI_BAUDR 0x14
+#define DW_SPI_TXFTLR 0x18
+#define DW_SPI_RXFTLR 0x1c
+#define DW_SPI_TXFLR 0x20
+#define DW_SPI_RXFLR 0x24
+#define DW_SPI_SR 0x28
+#define DW_SPI_IMR 0x2c
+#define DW_SPI_ISR 0x30
+#define DW_SPI_RISR 0x34
+#define DW_SPI_TXOICR 0x38
+#define DW_SPI_RXOICR 0x3c
+#define DW_SPI_RXUICR 0x40
+#define DW_SPI_MSTICR 0x44
+#define DW_SPI_ICR 0x48
+#define DW_SPI_DMACR 0x4c
+#define DW_SPI_DMATDLR 0x50
+#define DW_SPI_DMARDLR 0x54
+#define DW_SPI_IDR 0x58
+#define DW_SPI_VERSION 0x5c
+#define DW_SPI_DR 0x60
+#define DW_SPI_SPI_CTRL0 0xf4
+
+/* Bit fields in CTRLR0 */
+#define SPI_DFS_OFFSET 0
+#define SPI_DFS_MASK 0x1f
+#define SPI_DFS_8_BITS 0x7
+
+#define SPI_FRF_OFFSET 6
+#define SPI_FRF_SPI 0x0
+#define SPI_FRF_SSP 0x1
+#define SPI_FRF_MICROWIRE 0x2
+#define SPI_FRF_RESV 0x3
+
+#define SPI_MODE_OFFSET 8
+#define SPI_SCPH_OFFSET 8
+#define SPI_SCOL_OFFSET 9
+
+#define SPI_TMOD_OFFSET 10
+#define SPI_TMOD_MASK (0x3 << SPI_TMOD_OFFSET)
+#define SPI_TMOD_TR 0x0 /* xmit & recv */
+#define SPI_TMOD_TO 0x1 /* xmit only */
+#define SPI_TMOD_RO 0x2 /* recv only */
+#define SPI_TMOD_EPROMREAD 0x3 /* eeprom read mode */
+
+#define SPI_SLVOE_OFFSET 12
+#define SPI_SRL_OFFSET 13
+#define SPI_SSTE_OFFSET 14
+
+#define SPI_CFS_OFFSET 16
+#define SPI_CFS_MASK (0xf << SPI_CFS_OFFSET)
+
+#define SPI_SPI_FRF_OFFSET 22
+#define SPI_SPI_FRF_MASK (0x3 << SPI_SPI_FRF_OFFSET)
+#define SPI_STANDARD_FORMAT 0
+#define SPI_DUAL_FORMAT 1
+#define SPI_QUAD_FORMAT 2
+#define SPI_OCTAL_FORMAT 3
+
+#define DW_SPI_CTRL1_NDF_MASK 0xffff
+
+#define SPI_TXFTLR_TXFTHR_OFFSET 16
+
+/* Bit fields in SR, 7 bits */
+#define SR_MASK 0x7f
+#define SR_BUSY BIT(0)
+#define SR_TF_NOT_FULL BIT(1)
+#define SR_TF_EMPT BIT(2)
+#define SR_RF_NOT_EMPT BIT(3)
+#define SR_RF_FULL BIT(4)
+#define SR_TX_ERR BIT(5)
+#define SR_DCOL BIT(6)
+
+/* Bit fields in ISR, IMR, RISR, 7 bits */
+#define SPI_INT_TXEI BIT(0)
+#define SPI_INT_TXOI BIT(1)
+#define SPI_INT_RXUI BIT(2)
+#define SPI_INT_RXOI BIT(3)
+#define SPI_INT_RXFI BIT(4)
+#define SPI_INT_MSTI BIT(5)
+
+/* Bit fields in DMACR */
+#define SPI_DMA_RDMAE BIT(0)
+#define SPI_DMA_TDMAE BIT(1)
+
+/* Bit fields in SPI_CTRL0 */
+#define SPI_SPI_CTRL0_INST_L8 (0x2 << 8) /* two bit value */
+#define SPI_SPI_CTRL0_WAIT_8_CYCLE (0x8 << 11)/* five bit value */
+#define SPI_SPI_CTRL0_EN_CLK_STRETCH BIT(30)
+
+#define SPI_SPI_CTRL0_ADDR_L_OFFSET 2
+#define SPI_SPI_CTRL0_ADDR_L_MASK (0xf << SPI_SPI_CTRL0_ADDR_L_OFFSET)
+#define SPI_SPI_CTRL0_ADDR_L24 0x6 /* 3 bytes address */
+#define SPI_SPI_CTRL0_ADDR_L32 0x8 /* 4 bytes address */
+
+/* TX/RX FIFO maximum size */
+#define TX_FIFO_MAX_SIZE 256
+#define RX_FIFO_MAX_SIZE 256
+
+/* TX/RX interrupt level threshold, max is 256 */
+#define SPI_INT_THRESHOLD 32
+
+#define DW_SPI_MAX_CHIPSELECT 16
+
+struct dw_spi_flash_pdata {
+ struct mtd_info mtd;
+ struct spi_nor nor;
+ u32 clk_rate;
+};
+
+struct dw_spi_nor {
+ struct device *dev;
+ struct clk *clk;
+ unsigned int sclk;
+ void __iomem *regs;
+ unsigned int master_ref_clk_hz;
+ struct dw_spi_flash_pdata f_pdata[DW_SPI_MAX_CHIPSELECT];
+ bool clk_strech_en;
+ int supported_cs;
+ int current_cs;
+ unsigned int tx_fifo_len;
+ int rx_fifo_len;
+};
+
+static u32 dw_readl(struct dw_spi_nor *dws, u32 offset)
+{
+ return readl(dws->regs + offset);
+}
+
+static void dw_writel(struct dw_spi_nor *dws, u32 offset, u32 val)
+{
+ writel(val, dws->regs + offset);
+}
+
+static void dw_spi_enable_chip(struct dw_spi_nor *dws, int enable)
+{
+ dw_writel(dws, DW_SPI_SSIENR, (enable ? 1 : 0));
+}
+
+/* Disable IRQ bits */
+static void dw_spi_mask_intr(struct dw_spi_nor *dws, u32 mask)
+{
+ u32 new_mask;
+
+ new_mask = dw_readl(dws, DW_SPI_IMR) & ~mask;
+ dw_writel(dws, DW_SPI_IMR, new_mask);
+}
+
+/*
+ * This does disable the SPI controller, interrupts, and re-enable the
+ * controller back. Transmit and receive FIFO buffers are cleared when the
+ * device is disabled.
+ */
+static void dw_spi_reset_chip(struct dw_spi_nor *dw_spi)
+{
+ dw_spi_enable_chip(dw_spi, 0);
+ dw_spi_mask_intr(dw_spi, 0xff);
+ dw_spi_enable_chip(dw_spi, 1);
+}
+
+static int dw_spi_set_cs(struct dw_spi_nor *dw_spi, int cs)
+{
+ if (cs > dw_spi->supported_cs) {
+ dev_err(dw_spi->dev, "invalid chip select\n");
+ return -EINVAL;
+ }
+
+ dw_spi_enable_chip(dw_spi, 0);
+
+ if (cs == -1) {
+ /* no slave */
+ dw_writel(dw_spi, DW_SPI_SER, 0);
+ } else {
+ dw_writel(dw_spi, DW_SPI_SER, BIT(cs));
+ }
+ dw_spi->current_cs = cs;
+
+ dw_spi_enable_chip(dw_spi, 1);
+
+ return 0;
+}
+
+static void dw_spi_hw_init(struct dw_spi_nor *dw_spi)
+{
+ u32 ctrl0;
+ u32 spi_ctrl0;
+
+ dw_spi_reset_chip(dw_spi);
+ dw_spi_enable_chip(dw_spi, 0);
+
+ /* the line will automatically toggle between consecutive data frame */
+ ctrl0 = dw_readl(dw_spi, DW_SPI_CTRL0);
+ ctrl0 &= ~(SPI_DFS_MASK);
+ ctrl0 |= SPI_DFS_8_BITS;
+ ctrl0 &= ~(BIT(SPI_SSTE_OFFSET));
+ dw_writel(dw_spi, DW_SPI_CTRL0, ctrl0);
+
+ /* SPI_CTRL0 is initializtion */
+ spi_ctrl0 = SPI_SPI_CTRL0_INST_L8;
+ spi_ctrl0 |= SPI_SPI_CTRL0_ADDR_L32 << SPI_SPI_CTRL0_ADDR_L_OFFSET;
+ spi_ctrl0 |= SPI_SPI_CTRL0_WAIT_8_CYCLE;
+ spi_ctrl0 |= SPI_SPI_CTRL0_EN_CLK_STRETCH;
+
+ dw_writel(dw_spi, DW_SPI_SPI_CTRL0, spi_ctrl0);
+
+ dw_spi_enable_chip(dw_spi, 1);
+}
+
+static int dw_spi_of_get_flash_pdata(struct device *dev,
+ struct dw_spi_flash_pdata *f_pdata,
+ struct device_node *np)
+{
+ struct dw_spi_nor *dw_spi = dev->priv;
+ unsigned int max_clk_rate = dw_spi->master_ref_clk_hz / 2;
+
+ if (!np)
+ return 0;
+
+ if (of_property_read_u32(np, "spi-max-frequency", &f_pdata->clk_rate)) {
+ dev_err(dev, "couldn't determine spi-max-frequency\n");
+ return -ENXIO;
+ }
+
+ dev_dbg(dev, "spi-max-frequency = %u\n", f_pdata->clk_rate);
+
+ /* SPI clock cannot go higher than half the master ref clock */
+ if (f_pdata->clk_rate > max_clk_rate) {
+ f_pdata->clk_rate = max_clk_rate;
+ dev_warn(dev, "limiting SPI frequency to %u\n",
+ f_pdata->clk_rate);
+ }
+
+ return 0;
+}
+
+static int dw_spi_find_chipselect(struct spi_nor *nor)
+{
+ int cs = -1;
+ struct dw_spi_nor *dw_spi = nor->priv;
+
+ for (cs = 0; cs < dw_spi->supported_cs; cs++)
+ if (nor == &dw_spi->f_pdata[cs].nor)
+ break;
+ return cs;
+}
+
+static int dw_spi_wait_not_busy(struct dw_spi_nor *dw_spi)
+{
+ if (wait_on_timeout(100 * MSECOND,
+ !(dw_readl(dw_spi, DW_SPI_SR) & SR_BUSY))) {
+ dev_err(dw_spi->dev, "Timeout, wait not busy.\n");
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static bool dw_spi_tx_fifo_not_full(struct dw_spi_nor *dw_spi)
+{
+ return (dw_readl(dw_spi, DW_SPI_SR) & SR_TF_NOT_FULL) != 0;
+}
+
+static bool dw_spi_tx_fifo_empty(struct dw_spi_nor *dw_spi)
+{
+ return (dw_readl(dw_spi, DW_SPI_SR) & SR_TF_EMPT) != 0;
+}
+
+static bool dw_spi_rx_fifo_not_empty(struct dw_spi_nor *dw_spi)
+{
+ return (dw_readl(dw_spi, DW_SPI_SR) & SR_RF_NOT_EMPT) != 0;
+}
+
+static int dw_spi_is_enhanced(enum spi_nor_protocol proto)
+{
+ return proto != SNOR_PROTO_1_1_1;
+}
+
+static int dw_spi_rx_tx_fifo_overflow(struct dw_spi_nor *dw_spi)
+{
+ return dw_readl(dw_spi, DW_SPI_RISR) & (SPI_INT_RXOI | SPI_INT_TXOI);
+}
+
+static int dw_spi_config_baudrate_div(struct dw_spi_nor *dws, unsigned int sclk)
+{
+ unsigned int div;
+
+ dws->sclk = sclk;
+ div = dws->master_ref_clk_hz / sclk;
+ /* divisor value must be even */
+ div += div % 2;
+
+ dev_dbg(dws->dev, "configure clock divider (%u/%u) -> %u\n",
+ dws->master_ref_clk_hz, sclk, div);
+ dw_spi_enable_chip(dws, 0);
+ dw_writel(dws, DW_SPI_BAUDR, div);
+ dw_spi_enable_chip(dws, 1);
+
+ if (dw_readl(dws, DW_SPI_BAUDR) != div) {
+ dev_err(dws->dev, "Unable to configure clock divider\n");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static int dw_spi_prep_slave_cfg(struct spi_nor *nor)
+{
+ struct dw_spi_nor *dw_spi = nor->priv;
+ int cs = dw_spi_find_chipselect(nor);
+ struct dw_spi_flash_pdata *f_pdata;
+ unsigned int sclk;
+ int ret;
+
+ /* switch chip select */
+ if (dw_spi->current_cs != cs) {
+ ret = dw_spi_set_cs(dw_spi, cs);
+ if (ret)
+ return ret;
+ }
+
+ /* setup baudrate divisor */
+ f_pdata = &dw_spi->f_pdata[dw_spi->current_cs];
+ sclk = f_pdata->clk_rate;
+ if (dw_spi->sclk != sclk) {
+ ret = dw_spi_config_baudrate_div(dw_spi, sclk);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static void dw_spi_set_ctrl0(struct dw_spi_nor *dw_spi, u8 tmod, u8 frf)
+{
+ u32 ctrl0;
+
+ /* spi mode configuration */
+ ctrl0 = dw_readl(dw_spi, DW_SPI_CTRL0);
+ ctrl0 &= ~(SPI_TMOD_MASK | SPI_SPI_FRF_MASK);
+ ctrl0 |= tmod << SPI_TMOD_OFFSET;
+ ctrl0 |= frf << SPI_SPI_FRF_OFFSET;
+
+ dw_spi_enable_chip(dw_spi, 0);
+ dev_dbg(dw_spi->dev, "Setting ctrl0 to %x\n", ctrl0);
+ dw_writel(dw_spi, DW_SPI_CTRL0, ctrl0);
+ dw_spi_enable_chip(dw_spi, 1);
+}
+
+static int dw_spi_prep(struct spi_nor *nor, u8 tmod, u8 frf)
+{
+ int ret;
+ struct dw_spi_nor *dw_spi = nor->priv;
+
+ ret = dw_spi_prep_slave_cfg(nor);
+ if (ret)
+ return ret;
+
+ dw_spi_set_ctrl0(dw_spi, tmod, frf);
+
+ return 0;
+}
+
+static int dw_spi_set_addr_len(struct spi_nor *nor)
+{
+ struct dw_spi_nor *dw_spi = nor->priv;
+ u32 val, addr_l;
+
+ val = dw_readl(dw_spi, DW_SPI_SPI_CTRL0);
+ val &= ~SPI_SPI_CTRL0_ADDR_L_MASK;
+
+ if (nor->addr_width == 3) {
+ addr_l = SPI_SPI_CTRL0_ADDR_L24;
+ } else if (nor->addr_width == 4) {
+ addr_l = SPI_SPI_CTRL0_ADDR_L32;
+ } else {
+ dev_err(nor->dev, "unsupported addr_width %d\n",
+ nor->addr_width);
+ return -EINVAL;
+ }
+
+ val |= addr_l << SPI_SPI_CTRL0_ADDR_L_OFFSET;
+ dw_spi_enable_chip(dw_spi, 0);
+ dw_writel(dw_spi, DW_SPI_SPI_CTRL0, val);
+ dw_spi_enable_chip(dw_spi, 1);
+
+ return 0;
+}
+
+static int dw_spi_prep_enhanced(struct spi_nor *nor,
+ enum spi_nor_protocol proto, u8 tmod)
+{
+ int ret;
+ u8 frf;
+
+ switch (proto) {
+ case SNOR_PROTO_1_1_2:
+ dev_dbg(nor->dev, "dual mode\n");
+ frf = SPI_DUAL_FORMAT;
+ break;
+ case SNOR_PROTO_1_1_4:
+ dev_dbg(nor->dev, "quad mode\n");
+ frf = SPI_QUAD_FORMAT;
+ break;
+ default:
+ dev_err(nor->dev, "unsupported enhanced mode %d\n",
+ nor->read_proto);
+ return -EINVAL;
+ }
+
+ ret = dw_spi_set_addr_len(nor);
+ if (ret)
+ return ret;
+
+ return dw_spi_prep(nor, tmod, frf);
+}
+
+static int dw_spi_prep_std(struct spi_nor *nor, u8 tmod)
+{
+ return dw_spi_prep(nor, tmod, SPI_STANDARD_FORMAT);
+}
+
+static int dw_spi_read_enhanced(struct spi_nor *nor, const u8 opcode,
+ int address, u8 *rxbuf, size_t n_rx)
+{
+ struct dw_spi_nor *dw_spi = nor->priv;
+ u32 offset = 0;
+ int ret;
+
+ dw_spi_enable_chip(dw_spi, 0);
+ dw_writel(dw_spi, DW_SPI_CTRL1, n_rx - 1);
+ dw_spi_enable_chip(dw_spi, 1);
+
+ ret = dw_spi_wait_not_busy(dw_spi);
+ if (ret)
+ return ret;
+
+ /* send the opcode and the address */
+ dw_writel(dw_spi, DW_SPI_DR, opcode);
+ dw_writel(dw_spi, DW_SPI_DR, address);
+
+ while (n_rx) {
+ if (dw_spi_rx_fifo_not_empty(dw_spi)) {
+ rxbuf[offset++] = dw_readl(dw_spi, DW_SPI_DR);
+ n_rx--;
+ }
+
+ /* check RX/TX overflow */
+ if (dw_spi_rx_tx_fifo_overflow(dw_spi))
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int dw_spi_read_std(struct spi_nor *nor, const u8 opcode, int address,
+ u8 *rxbuf, unsigned int n_rx)
+{
+ struct dw_spi_nor *dw_spi = nor->priv;
+ int tx_cnt = n_rx, rx_cnt = n_rx, skip_rx, cur_rx = 0;
+ int ret = 0, i, txfhr, rx_free;
+ u32 tmp_val;
+
+ ret = dw_spi_wait_not_busy(dw_spi);
+ if (ret)
+ return ret;
+
+ /* clear interrupts */
+ dw_readl(dw_spi, DW_SPI_ICR);
+
+ /* TX fifo must not became empty during the frame transfer:
+ * use TXFTHR (Transfert Start FIFO level) to avoid the frame
+ * to start during the first phase computation */
+ skip_rx = 1 /* opcode */ + nor->addr_width;
+ txfhr = min_t(unsigned int, skip_rx + n_rx, dw_spi->tx_fifo_len) - 1;
+ rx_free = dw_spi->rx_fifo_len - skip_rx;
+
+ dw_spi_enable_chip(dw_spi, 0);
+ dw_writel(dw_spi, DW_SPI_TXFTLR, txfhr << SPI_TXFTLR_TXFTHR_OFFSET);
+ dw_writel(dw_spi, DW_SPI_RXFTLR, dw_spi->rx_fifo_len / 2);
+ dw_spi_enable_chip(dw_spi, 1);
+
+ /* opcode phase */
+ dw_writel(dw_spi, DW_SPI_DR, opcode);
+
+ /* address phase in TR mode */
+ for (i = nor->addr_width - 1; i >= 0; i--)
+ dw_writel(dw_spi, DW_SPI_DR, (address >> (8 * i)) & 0xff);
+
+ while (rx_cnt) {
+ /* push dummy bytes to receive data */
+ while (tx_cnt && dw_spi_tx_fifo_not_full(dw_spi) &&
+ rx_free > 0) {
+ dw_writel(dw_spi, DW_SPI_DR, 0xff);
+ tx_cnt--;
+ rx_free--;
+ }
+
+ if (dw_spi_rx_fifo_not_empty(dw_spi)) {
+ tmp_val = dw_readl(dw_spi, DW_SPI_DR);
+ rx_free++;
+ if (skip_rx) {
+ skip_rx--;
+ continue;
+ }
+
+ rxbuf[cur_rx++] = tmp_val;
+ rx_cnt--;
+ }
+ if (dw_spi_rx_tx_fifo_overflow(dw_spi))
+ return -EIO;
+ }
+
+ return n_rx;
+}
+
+static int dw_spi_wait_tx_end(struct dw_spi_nor *dw_spi)
+{
+ int res;
+
+ /* As specified in ssi_user_guide p63 the BUSY bit cannot be polled
+ * immediately. As indicated in ssi_databook p40 the TFE bit shall
+ * be tested before testing busy bit
+ */
+ res = wait_on_timeout(100 * MSECOND, dw_spi_tx_fifo_empty(dw_spi));
+ if (res < 0) {
+ dev_err(dw_spi->dev, "SPI write failure, TX FIFO is never empty\n");
+ return res;
+ }
+
+ return dw_spi_wait_not_busy(dw_spi);
+}
+
+static int dw_spi_write_enhanced(struct spi_nor *nor, u8 opcode, u32 address,
+ u8 *txbuf, unsigned int n_tx)
+{
+ struct dw_spi_nor *dw_spi = nor->priv;
+ size_t tx_cnt = 0;
+
+ dw_spi_enable_chip(dw_spi, 0);
+ dw_writel(dw_spi, DW_SPI_CTRL1, n_tx - 1);
+ dw_spi_enable_chip(dw_spi, 1);
+
+ dw_writel(dw_spi, DW_SPI_DR, opcode);
+ dw_writel(dw_spi, DW_SPI_DR, address);
+
+ /* send data */
+ while (tx_cnt < n_tx) {
+ if (dw_spi_tx_fifo_not_full(dw_spi)) {
+ dw_writel(dw_spi, DW_SPI_DR, txbuf[tx_cnt]);
+ tx_cnt++;
+ }
+ }
+
+ return dw_spi_wait_tx_end(dw_spi);
+}
+
+static int dw_spi_write_std(struct spi_nor *nor, const u8 *opbuf,
+ unsigned int n_op, u8 *txbuf, unsigned int n_tx)
+{
+ struct dw_spi_nor *dw_spi = nor->priv;
+ int op_cnt = 0, tx_cnt = 0, txfhr;
+
+ txfhr = min_t(unsigned int, dw_spi->tx_fifo_len, n_op + n_tx) - 1;
+ dw_spi_enable_chip(dw_spi, 0);
+ dw_writel(dw_spi, DW_SPI_TXFTLR, txfhr << SPI_TXFTLR_TXFTHR_OFFSET);
+ dw_spi_enable_chip(dw_spi, 1);
+
+ /* send opcodes */
+ while (op_cnt < n_op) {
+ if (dw_spi_tx_fifo_not_full(dw_spi)) {
+ dw_writel(dw_spi, DW_SPI_DR, opbuf[op_cnt]);
+ op_cnt++;
+ }
+ }
+
+ /* send data */
+ while (tx_cnt < n_tx) {
+ if (dw_spi_tx_fifo_not_full(dw_spi)) {
+ dw_writel(dw_spi, DW_SPI_DR, txbuf[tx_cnt]);
+ tx_cnt++;
+ }
+ }
+
+ return dw_spi_wait_tx_end(dw_spi);
+}
+
+static int dw_spi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+ int i, ret;
+
+ ret = dw_spi_prep_std(nor, SPI_TMOD_TR);
+ if (ret)
+ return ret;
+
+ ret = dw_spi_read_std(nor, opcode, -1, buf, len);
+
+ dev_dbg(nor->dev, "read_reg opcode 0x%02x: ", opcode);
+ for (i = 0; i < len; i++)
+ pr_debug("%02x ", buf[i]);
+ pr_debug("\n");
+
+ return ret;
+}
+
+static int dw_spi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+ int i, ret;
+
+ dev_dbg(nor->dev, "write_reg opcode 0x%02x: ", opcode);
+ for (i = 0; i < len; i++)
+ pr_debug("%02x ", buf[i]);
+ pr_debug("\n");
+
+ if (!IS_ENABLED(CONFIG_MTD_WRITE))
+ return -ENOTSUPP;
+
+ ret = dw_spi_prep_std(nor, SPI_TMOD_TO);
+ if (ret)
+ return ret;
+
+ return dw_spi_write_std(nor, &opcode, 1, buf, len);
+}
+
+static void dw_spi_write(struct spi_nor *nor, loff_t to,
+ size_t len, size_t *retlen, const u_char *buf)
+{
+ u8 opcode[8];
+ unsigned int opcode_len = 0;
+ int i, ret;
+ struct dw_spi_nor *dw_spi = nor->priv;
+
+ *retlen = 0;
+ dev_dbg(dw_spi->dev, "write %ld bytes at @0x%llx\n", len, to);
+
+ if (!IS_ENABLED(CONFIG_MTD_WRITE))
+ return;
+
+ if (dw_spi_is_enhanced(nor->write_proto)) {
+ if (dw_spi_prep_enhanced(nor, nor->write_proto, SPI_TMOD_TO))
+ return;
+
+ ret = dw_spi_write_enhanced(nor, nor->program_opcode, to,
+ (u8 *)buf, len);
+ } else {
+ if (dw_spi_prep_std(nor, SPI_TMOD_TO))
+ return;
+
+ opcode[0] = nor->program_opcode;
+ opcode_len = 1 + nor->addr_width;
+ for (i = 0; i < nor->addr_width; i++)
+ opcode[1 + i] =
+ (to >> (8 * (nor->addr_width - 1 - i))) & 0xff;
+
+ ret = dw_spi_write_std(nor, opcode, opcode_len, (u8 *)buf, len);
+ }
+
+ if (ret == 0)
+ *retlen = len;
+}
+
+static int dw_spi_read(struct spi_nor *nor, loff_t from,
+ size_t len, size_t *retlen, u_char *buf)
+{
+ struct dw_spi_nor *dw_spi = nor->priv;
+ size_t to_read, orig_len = len;
+ u8 *ptr = (u8 *)buf;
+ loff_t offset = from;
+ int ret = 0, enhanced = dw_spi_is_enhanced(nor->read_proto);
+ size_t chunk;
+
+ *retlen = 0;
+ dev_dbg(nor->dev, "read %ld bytes from @0x%llx\n", len, from);
+
+ if (enhanced)
+ ret = dw_spi_prep_enhanced(nor, nor->read_proto, SPI_TMOD_RO);
+ else
+ ret = dw_spi_prep_std(nor, SPI_TMOD_TR);
+ if (ret)
+ return ret;
+
+ /*
+ * If clock stretching is not supported, we have no way to prevent RX
+ * overflow except reducing the number received data to the size of the
+ * RX fifo
+ */
+ if (dw_spi->clk_strech_en && enhanced)
+ chunk = DW_SPI_CTRL1_NDF_MASK;
+ else
+ chunk = dw_spi->rx_fifo_len;
+
+ while (len) {
+ to_read = min(chunk, len);
+
+ if (enhanced)
+ ret = dw_spi_read_enhanced(nor, nor->read_opcode,
+ offset, ptr, to_read);
+ else
+ ret = dw_spi_read_std(nor, nor->read_opcode,
+ offset, ptr, to_read);
+ if (ret < 0)
+ return ret;
+
+ offset += to_read;
+ ptr += to_read;
+ len -= to_read;
+ }
+ *retlen = orig_len;
+
+ return ret;
+}
+
+static int dw_spi_erase(struct spi_nor *nor, loff_t offs)
+{
+ int ret = 0;
+ int i;
+ u8 buf[SPI_NOR_MAX_ADDR_WIDTH]; /* addr is 3 or 4 bytes */
+
+ dev_dbg(nor->dev, "erase(%0x) @0x%llx\n", nor->erase_opcode, offs);
+
+ for (i = nor->addr_width - 1; i >= 0; i--) {
+ buf[i] = offs & 0xff;
+ offs >>= 8;
+ }
+
+ ret = dw_spi_prep_std(nor, SPI_TMOD_TO);
+ if (ret)
+ return ret;
+
+ /* Caller is responsible for enabling write,
+ * only send the erase sector command */
+ ret = nor->write_reg(nor, nor->erase_opcode, buf,
+ nor->addr_width);
+
+ /* Caller is responsible to wait for operation completion */
+ return ret;
+}
+
+static int dw_spi_setup_flash(struct device *dev,
+ struct dw_spi_flash_pdata *f_pdata,
+ struct device_node *np)
+{
+ const struct spi_nor_hwcaps hwcaps = {
+ .mask = SNOR_HWCAPS_READ |
+ SNOR_HWCAPS_READ_FAST |
+ SNOR_HWCAPS_READ_1_1_2 |
+ SNOR_HWCAPS_READ_1_1_4 |
+ SNOR_HWCAPS_PP |
+ SNOR_HWCAPS_PP_1_1_4,
+ };
+ struct dw_spi_nor *dw_spi = dev->priv;
+ struct mtd_info *mtd;
+ struct spi_nor *nor;
+ int ret;
+
+ ret = dw_spi_of_get_flash_pdata(dev, f_pdata, np);
+ if (ret)
+ goto probe_failed;
+
+ nor = &f_pdata->nor;
+ mtd = &f_pdata->mtd;
+ nor->mtd = mtd;
+
+ if (np) {
+ nor->dev = kzalloc(sizeof(*nor->dev), GFP_KERNEL);
+ if (!nor->dev)
+ return -ENOMEM;
+
+ dev_set_name(nor->dev, np->name);
+
+ nor->dev->of_node = np;
+ nor->dev->id = DEVICE_ID_SINGLE;
+ nor->dev->parent = dev;
+ ret = register_device(nor->dev);
+ if (ret)
+ return ret;
+
+ mtd->dev.parent = nor->dev;
+ } else {
+ nor->dev = dev;
+ }
+
+ nor->priv = dw_spi;
+ mtd->priv = nor;
+
+ nor->read_reg = dw_spi_read_reg;
+ nor->write_reg = dw_spi_write_reg;
+ nor->read = dw_spi_read;
+ nor->write = dw_spi_write;
+ nor->erase = dw_spi_erase;
+
+ ret = spi_nor_scan(nor, NULL, &hwcaps, false);
+ if (ret)
+ goto probe_failed;
+
+ ret = add_mtd_device(mtd, NULL, DEVICE_ID_DYNAMIC);
+ if (ret)
+ goto probe_failed;
+
+ return 0;
+
+probe_failed:
+ dev_err(dev, "probing for flashchip failed\n");
+ return ret;
+}
+
+static void dw_spi_detect_hw_params(struct dw_spi_nor *dw_spi)
+{
+ int fifo;
+
+ /* Detect supported slave number */
+ dw_spi_enable_chip(dw_spi, 0);
+ dw_writel(dw_spi, DW_SPI_SER, 0xffff);
+ dw_spi_enable_chip(dw_spi, 1);
+ dw_spi->supported_cs = hweight32(dw_readl(dw_spi, DW_SPI_SER));
+
+ dw_spi_set_cs(dw_spi, -1);
+ dw_spi->sclk = 0;
+
+ /* Detect the FIFO depth */
+ dw_spi_enable_chip(dw_spi, 0);
+ for (fifo = 1; fifo < TX_FIFO_MAX_SIZE; fifo++) {
+ dw_writel(dw_spi, DW_SPI_TXFTLR, fifo);
+ if (fifo != dw_readl(dw_spi, DW_SPI_TXFTLR))
+ break;
+ }
+ dw_writel(dw_spi, DW_SPI_TXFTLR, 0);
+ dw_spi->tx_fifo_len = (fifo == 1) ? 0 : fifo;
+ dev_dbg(dw_spi->dev, "Detected TX FIFO size: %u bytes\n",
+ dw_spi->tx_fifo_len);
+
+ for (fifo = 1; fifo < RX_FIFO_MAX_SIZE; fifo++) {
+ dw_writel(dw_spi, DW_SPI_RXFTLR, fifo);
+ if (fifo != dw_readl(dw_spi, DW_SPI_RXFTLR))
+ break;
+ }
+ dw_writel(dw_spi, DW_SPI_RXFTLR, 0);
+ dw_spi->rx_fifo_len = (fifo == 1) ? 0 : fifo;
+ dev_dbg(dw_spi->dev, "Detected RX FIFO size: %u bytes\n",
+ dw_spi->tx_fifo_len);
+ dw_spi_enable_chip(dw_spi, 1);
+}
+
+static int dw_spi_probe(struct device *dev)
+{
+ struct dw_spi_nor *dw_spi;
+ struct resource *iores;
+ struct device_node *np = dev->of_node;
+ struct dw_spi_flash_pdata *f_pdata = NULL;
+ int ret;
+
+ dw_spi = kzalloc(sizeof(*dw_spi), GFP_KERNEL);
+ if (!dw_spi)
+ return -ENOMEM;
+
+ dw_spi->dev = dev;
+ dev->priv = dw_spi;
+
+ dw_spi->clk = clk_get(dev, NULL);
+ if (IS_ERR(dw_spi->clk)) {
+ dev_err(dev, "unable to get spi clk\n");
+ ret = PTR_ERR(dw_spi->clk);
+ goto probe_failed;
+ }
+
+ dw_spi->master_ref_clk_hz = clk_get_rate(dw_spi->clk);
+ if (dw_spi->master_ref_clk_hz == 0) {
+ dev_err(dev, "unable to get spi clk rate\n");
+ ret = PTR_ERR(dw_spi->clk);
+ goto probe_failed;
+ }
+
+ clk_enable(dw_spi->clk);
+
+ iores = dev_request_mem_resource(dev, 0);
+ if (IS_ERR(iores)) {
+ dev_err(dev, "dev_request_mem_region failed\n");
+ ret = PTR_ERR(iores);
+ goto probe_failed;
+ }
+ dw_spi->regs = IOMEM(iores->start);
+
+ dw_spi_hw_init(dw_spi);
+
+ dw_spi_detect_hw_params(dw_spi);
+
+ /* Get clock stretching mode support from device-tree */
+ dw_spi->clk_strech_en = of_property_read_bool(dev->of_node,
+ "clock-stretching");
+ dev_dbg(dev, "clock stretching %s supported\n",
+ dw_spi->clk_strech_en ? "is" : "is not");
+
+ if (!dev->of_node) {
+ f_pdata = &dw_spi->f_pdata[0];
+
+ ret = dw_spi_setup_flash(dev, f_pdata, np);
+ if (ret)
+ goto probe_failed;
+ } else {
+ /* Get flash device data */
+ for_each_available_child_of_node(dev->of_node, np) {
+ unsigned int cs;
+
+ if (of_property_read_u32(np, "reg", &cs)) {
+ dev_err(dev, "couldn't determine chip select\n");
+ ret = -ENXIO;
+ goto probe_failed;
+ }
+ if (cs > dw_spi->supported_cs) {
+ dev_err(dev, "chip select %d out of range (%d supported)\n",
+ cs, dw_spi->supported_cs);
+ ret = -ENXIO;
+ goto probe_failed;
+ }
+ f_pdata = &dw_spi->f_pdata[cs];
+
+ ret = dw_spi_setup_flash(dev, f_pdata, np);
+ if (ret)
+ goto probe_failed;
+ }
+ }
+
+ dev_info(dev, "Synopsys Octal SPI NOR flash driver\n");
+ return 0;
+
+probe_failed:
+ dev_err(dev, "probe failed: %d\n", ret);
+ return ret;
+}
+
+static __maybe_unused struct of_device_id dw_spi_dt_ids[] = {
+ { .compatible = "snps,ospi-nor", },
+ { /* sentinel */ }
+};
+
+static struct driver dw_spi_driver = {
+ .name = "dw_ospi_nor",
+ .probe = dw_spi_probe,
+ .of_compatible = DRV_OF_COMPAT(dw_spi_dt_ids),
+};
+device_platform_driver(dw_spi_driver);
--
2.17.1
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