Import the U-Boot v2022.04-rc2 driver to enable access to SPI flash and
SD over SPI on the HiFive Unleashed. Tested with QEMU.
Signed-off-by: Ahmad Fatoum <ahmad@xxxxxx>
---
v1 -> v2:
- remove unused wait_for_bit (Sascha)
- move prep and CS handling out of transfer_one into callers (Sascha)
- Use nbytes instead of bitlen as code is bytewise anyway (Sascha)
- remove superfluous pos variable (Sascha)
---
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-sifive.c | 521 +++++++++++++++++++++++++++++++++++++++
3 files changed, 528 insertions(+)
create mode 100644 drivers/spi/spi-sifive.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 7df7561718c2..8935feb97b99 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -124,6 +124,12 @@ config SPI_NXP_FLEXSPI
This controller does not support generic SPI messages and only
supports the high-level SPI memory interface.
+config SPI_SIFIVE
+ tristate "SiFive SPI controller"
+ depends on SOC_SIFIVE || COMPILE_TEST
+ help
+ This exposes the SPI controller IP from SiFive.
+
endif
endmenu
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 64c8e2645a94..3455eea86988 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_DRIVER_SPI_DSPI) += dspi_spi.o
obj-$(CONFIG_SPI_ZYNQ_QSPI) += zynq_qspi.o
obj-$(CONFIG_SPI_NXP_FLEXSPI) += spi-nxp-fspi.o
obj-$(CONFIG_DRIVER_SPI_STM32) += stm32_spi.o
+obj-$(CONFIG_SPI_SIFIVE) += spi-sifive.o
diff --git a/drivers/spi/spi-sifive.c b/drivers/spi/spi-sifive.c
new file mode 100644
index 000000000000..713bcc0c3bd8
--- /dev/null
+++ b/drivers/spi/spi-sifive.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 SiFive, Inc.
+ * Copyright 2019 Bhargav Shah <bhargavshah1988@xxxxxxxxx>
+ *
+ * SiFive SPI controller driver (master mode only)
+ */
+
+#include <common.h>
+#include <linux/clk.h>
+#include <driver.h>
+#include <init.h>
+#include <errno.h>
+#include <linux/reset.h>
+#include <spi/spi.h>
+#include <linux/spi/spi-mem.h>
+#include <linux/bitops.h>
+#include <clock.h>
+#include <gpio.h>
+#include <of_gpio.h>
+#include <linux/bitfield.h>
+#include <linux/iopoll.h>
+#include <linux/log2.h>
+
+#define SIFIVE_SPI_MAX_CS 32
+
+#define SIFIVE_SPI_DEFAULT_DEPTH 8
+#define SIFIVE_SPI_DEFAULT_BITS 8
+
+/* register offsets */
+#define SIFIVE_SPI_REG_SCKDIV 0x00 /* Serial clock divisor */
+#define SIFIVE_SPI_REG_SCKMODE 0x04 /* Serial clock mode */
+#define SIFIVE_SPI_REG_CSID 0x10 /* Chip select ID */
+#define SIFIVE_SPI_REG_CSDEF 0x14 /* Chip select default */
+#define SIFIVE_SPI_REG_CSMODE 0x18 /* Chip select mode */
+#define SIFIVE_SPI_REG_DELAY0 0x28 /* Delay control 0 */
+#define SIFIVE_SPI_REG_DELAY1 0x2c /* Delay control 1 */
+#define SIFIVE_SPI_REG_FMT 0x40 /* Frame format */
+#define SIFIVE_SPI_REG_TXDATA 0x48 /* Tx FIFO data */
+#define SIFIVE_SPI_REG_RXDATA 0x4c /* Rx FIFO data */
+#define SIFIVE_SPI_REG_TXMARK 0x50 /* Tx FIFO watermark */
+#define SIFIVE_SPI_REG_RXMARK 0x54 /* Rx FIFO watermark */
+#define SIFIVE_SPI_REG_FCTRL 0x60 /* SPI flash interface control */
+#define SIFIVE_SPI_REG_FFMT 0x64 /* SPI flash instruction format */
+#define SIFIVE_SPI_REG_IE 0x70 /* Interrupt Enable Register */
+#define SIFIVE_SPI_REG_IP 0x74 /* Interrupt Pendings Register */
+
+/* sckdiv bits */
+#define SIFIVE_SPI_SCKDIV_DIV_MASK 0xfffU
+
+/* sckmode bits */
+#define SIFIVE_SPI_SCKMODE_PHA BIT(0)
+#define SIFIVE_SPI_SCKMODE_POL BIT(1)
+#define SIFIVE_SPI_SCKMODE_MODE_MASK (SIFIVE_SPI_SCKMODE_PHA | \
+ SIFIVE_SPI_SCKMODE_POL)
+
+/* csmode bits */
+#define SIFIVE_SPI_CSMODE_MODE_AUTO 0U
+#define SIFIVE_SPI_CSMODE_MODE_HOLD 2U
+#define SIFIVE_SPI_CSMODE_MODE_OFF 3U
+
+/* delay0 bits */
+#define SIFIVE_SPI_DELAY0_CSSCK(x) ((u32)(x))
+#define SIFIVE_SPI_DELAY0_CSSCK_MASK 0xffU
+#define SIFIVE_SPI_DELAY0_SCKCS(x) ((u32)(x) << 16)
+#define SIFIVE_SPI_DELAY0_SCKCS_MASK (0xffU << 16)
+
+/* delay1 bits */
+#define SIFIVE_SPI_DELAY1_INTERCS(x) ((u32)(x))
+#define SIFIVE_SPI_DELAY1_INTERCS_MASK 0xffU
+#define SIFIVE_SPI_DELAY1_INTERXFR(x) ((u32)(x) << 16)
+#define SIFIVE_SPI_DELAY1_INTERXFR_MASK (0xffU << 16)
+
+/* fmt bits */
+#define SIFIVE_SPI_FMT_PROTO_SINGLE 0U
+#define SIFIVE_SPI_FMT_PROTO_DUAL 1U
+#define SIFIVE_SPI_FMT_PROTO_QUAD 2U
+#define SIFIVE_SPI_FMT_PROTO_MASK 3U
+#define SIFIVE_SPI_FMT_ENDIAN BIT(2)
+#define SIFIVE_SPI_FMT_DIR BIT(3)
+#define SIFIVE_SPI_FMT_LEN(x) ((u32)(x) << 16)
+#define SIFIVE_SPI_FMT_LEN_MASK (0xfU << 16)
+
+/* txdata bits */
+#define SIFIVE_SPI_TXDATA_DATA_MASK 0xffU
+#define SIFIVE_SPI_TXDATA_FULL BIT(31)
+
+/* rxdata bits */
+#define SIFIVE_SPI_RXDATA_DATA_MASK 0xffU
+#define SIFIVE_SPI_RXDATA_EMPTY BIT(31)
+
+/* ie and ip bits */
+#define SIFIVE_SPI_IP_TXWM BIT(0)
+#define SIFIVE_SPI_IP_RXWM BIT(1)
+
+/* format protocol */
+#define SIFIVE_SPI_PROTO_QUAD 4 /* 4 lines I/O protocol transfer */
+#define SIFIVE_SPI_PROTO_DUAL 2 /* 2 lines I/O protocol transfer */
+#define SIFIVE_SPI_PROTO_SINGLE 1 /* 1 line I/O protocol transfer */
+
+#define SPI_XFER_BEGIN 0x01 /* Assert CS before transfer */
+#define SPI_XFER_END 0x02 /* Deassert CS after transfer */
+
+struct sifive_spi {
+ struct spi_controller ctlr;
+ void __iomem *regs; /* base address of the registers */
+ u32 fifo_depth;
+ u32 bits_per_word;
+ u32 cs_inactive; /* Level of the CS pins when inactive*/
+ u32 freq;
+ u8 fmt_proto;
+};
+
+static inline struct sifive_spi *to_sifive_spi(struct spi_controller *ctlr)
+{
+ return container_of(ctlr, struct sifive_spi, ctlr);
+}
+
+static void sifive_spi_prep_device(struct sifive_spi *spi,
+ struct spi_device *spi_dev)
+{
+ /* Update the chip select polarity */
+ if (spi_dev->mode & SPI_CS_HIGH)
+ spi->cs_inactive &= ~BIT(spi_dev->chip_select);
+ else
+ spi->cs_inactive |= BIT(spi_dev->chip_select);
+ writel(spi->cs_inactive, spi->regs + SIFIVE_SPI_REG_CSDEF);
+
+ /* Select the correct device */
+ writel(spi_dev->chip_select, spi->regs + SIFIVE_SPI_REG_CSID);
+}
+
+static void sifive_spi_set_cs(struct sifive_spi *spi,
+ struct spi_device *spi_dev)
+{
+ u32 cs_mode = SIFIVE_SPI_CSMODE_MODE_HOLD;
+
+ if (spi_dev->mode & SPI_CS_HIGH)
+ cs_mode = SIFIVE_SPI_CSMODE_MODE_AUTO;
+
+ writel(cs_mode, spi->regs + SIFIVE_SPI_REG_CSMODE);
+}
+
+static void sifive_spi_clear_cs(struct sifive_spi *spi)
+{
+ writel(SIFIVE_SPI_CSMODE_MODE_AUTO, spi->regs + SIFIVE_SPI_REG_CSMODE);
+}
+
+static void sifive_spi_prep_transfer(struct sifive_spi *spi,
+ struct spi_device *spi_dev,
+ u8 *rx_ptr)
+{
+ u32 cr;
+
+ /* Modify the SPI protocol mode */
+ cr = readl(spi->regs + SIFIVE_SPI_REG_FMT);
+
+ /* Bits per word ? */
+ cr &= ~SIFIVE_SPI_FMT_LEN_MASK;
+ cr |= SIFIVE_SPI_FMT_LEN(spi->bits_per_word);
+
+ /* LSB first? */
+ cr &= ~SIFIVE_SPI_FMT_ENDIAN;
+ if (spi_dev->mode & SPI_LSB_FIRST)
+ cr |= SIFIVE_SPI_FMT_ENDIAN;
+
+ /* Number of wires ? */
+ cr &= ~SIFIVE_SPI_FMT_PROTO_MASK;
+ switch (spi->fmt_proto) {
+ case SIFIVE_SPI_PROTO_QUAD:
+ cr |= SIFIVE_SPI_FMT_PROTO_QUAD;
+ break;
+ case SIFIVE_SPI_PROTO_DUAL:
+ cr |= SIFIVE_SPI_FMT_PROTO_DUAL;
+ break;
+ default:
+ cr |= SIFIVE_SPI_FMT_PROTO_SINGLE;
+ break;
+ }
+
+ /* SPI direction in/out ? */
+ cr &= ~SIFIVE_SPI_FMT_DIR;
+ if (!rx_ptr)
+ cr |= SIFIVE_SPI_FMT_DIR;
+
+ writel(cr, spi->regs + SIFIVE_SPI_REG_FMT);
+}
+
+static void sifive_spi_rx(struct sifive_spi *spi, u8 *rx_ptr)
+{
+ u32 data;
+
+ do {
+ data = readl(spi->regs + SIFIVE_SPI_REG_RXDATA);
+ } while (data & SIFIVE_SPI_RXDATA_EMPTY);
+
+ if (rx_ptr)
+ *rx_ptr = data & SIFIVE_SPI_RXDATA_DATA_MASK;
+}
+
+static void sifive_spi_tx(struct sifive_spi *spi, const u8 *tx_ptr)
+{
+ u32 data;
+ u8 tx_data = (tx_ptr) ? *tx_ptr & SIFIVE_SPI_TXDATA_DATA_MASK :
+ SIFIVE_SPI_TXDATA_DATA_MASK;
+
+ do {
+ data = readl(spi->regs + SIFIVE_SPI_REG_TXDATA);
+ } while (data & SIFIVE_SPI_TXDATA_FULL);
+
+ writel(tx_data, spi->regs + SIFIVE_SPI_REG_TXDATA);
+}
+
+static int sifive_spi_wait(struct sifive_spi *spi, u32 mask)
+{
+ u32 val;
+
+ return readl_poll_timeout(spi->regs + SIFIVE_SPI_REG_IP, val,
+ (val & mask) == mask, 100 * USEC_PER_MSEC);
+}
+
+static int sifive_spi_transfer_one(struct spi_device *spi_dev, unsigned int nbytes,
+ const void *dout, void *din)
+{
+ struct sifive_spi *spi = to_sifive_spi(spi_dev->controller);
+ const u8 *tx_ptr = dout;
+ u8 *rx_ptr = din;
+ int ret;
+
+ sifive_spi_prep_transfer(spi, spi_dev, rx_ptr);
+
+ while (nbytes) {
+ unsigned int n_words = min(nbytes, spi->fifo_depth);
+ unsigned int tx_words, rx_words;
+
+ /* Enqueue n_words for transmission */
+ for (tx_words = 0; tx_words < n_words; tx_words++) {
+ if (!tx_ptr)
+ sifive_spi_tx(spi, NULL);
+ else
+ sifive_spi_tx(spi, tx_ptr++);
+ }
+
+ if (rx_ptr) {
+ /* Wait for transmission + reception to complete */
+ writel(n_words - 1, spi->regs + SIFIVE_SPI_REG_RXMARK);
+ ret = sifive_spi_wait(spi, SIFIVE_SPI_IP_RXWM);
+ if (ret)
+ return ret;
+
+ /* Read out all the data from the RX FIFO */
+ for (rx_words = 0; rx_words < n_words; rx_words++)
+ sifive_spi_rx(spi, rx_ptr++);
+ } else {
+ /* Wait for transmission to complete */
+ ret = sifive_spi_wait(spi, SIFIVE_SPI_IP_TXWM);
+ if (ret)
+ return ret;
+ }
+
+ nbytes -= n_words;
+ }
+
+ return 0;
+}
+
+static int sifive_spi_transfer(struct spi_device *spi_dev, struct spi_message *msg)
+{
+ struct spi_controller *ctlr = spi_dev->controller;
+ struct sifive_spi *spi = to_sifive_spi(ctlr);
+ struct spi_transfer *t;
+ int ret = 0;
+
+ if (list_empty(&msg->transfers))
+ return 0;
+
+ msg->actual_length = 0;
+
+ sifive_spi_prep_device(spi, spi_dev);
+ sifive_spi_set_cs(spi, spi_dev);
+
+ dev_dbg(ctlr->dev, "transfer start actual_length=%i\n", msg->actual_length);
+ list_for_each_entry(t, &msg->transfers, transfer_list) {
+ dev_dbg(ctlr->dev, " xfer %p: len %u tx %p rx %p\n",
+ t, t->len, t->tx_buf, t->rx_buf);
+
+ ret = sifive_spi_transfer_one(spi_dev, t->len,
+ t->tx_buf, t->rx_buf);
+ if (ret < 0)
+ goto out;
+ msg->actual_length += t->len;
+ }
+ dev_dbg(ctlr->dev, "transfer done actual_length=%i\n", msg->actual_length);
+
+out:
+ sifive_spi_clear_cs(spi);
+ return ret;
+}
+
+static int sifive_spi_exec_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ struct spi_device *spi_dev = mem->spi;
+ struct device_d *dev = &spi_dev->dev;
+ struct sifive_spi *spi = spi_controller_get_devdata(spi_dev->controller);
+ u8 opcode = op->cmd.opcode;
+ int ret;
+
+ spi->fmt_proto = op->cmd.buswidth;
+
+ sifive_spi_prep_device(spi, spi_dev);
+ sifive_spi_set_cs(spi, spi_dev);
+
+ /* send the opcode */
+ ret = sifive_spi_transfer_one(spi_dev, 1, &opcode, NULL);
+ if (ret < 0) {
+ dev_err(dev, "failed to xfer opcode\n");
+ goto out;
+ }
+
+ if (!op->addr.nbytes && !op->data.nbytes)
+ goto out;
+
+ /* send the addr + dummy */
+ if (op->addr.nbytes) {
+ int i, op_len = op->addr.nbytes + op->dummy.nbytes;
+ u8 *op_buf;
+
+ op_buf = malloc(op_len);
+ if (!op_buf) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ /* fill address */
+ for (i = 0; i < op->addr.nbytes; i++)
+ op_buf[i] = op->addr.val >>
+ (8 * (op->addr.nbytes - i - 1));
+
+ /* fill dummy */
+ memset(op_buf + op->addr.nbytes, 0xff, op->dummy.nbytes);
+
+ spi->fmt_proto = op->addr.buswidth;
+
+ ret = sifive_spi_transfer_one(spi_dev, op_len, op_buf, NULL);
+ free(op_buf);
+ if (ret < 0) {
+ dev_err(dev, "failed to xfer addr + dummy\n");
+ goto out;
+ }
+ }
+
+ /* send/received the data */
+ if (op->data.nbytes) {
+ const void *tx_buf = NULL;
+ void *rx_buf = NULL;
+
+ if (op->data.dir == SPI_MEM_DATA_IN)
+ rx_buf = op->data.buf.in;
+ else
+ tx_buf = op->data.buf.out;
+
+ spi->fmt_proto = op->data.buswidth;
+
+ ret = sifive_spi_transfer_one(spi_dev, op->data.nbytes,
+ tx_buf, rx_buf);
+ if (ret) {
+ dev_err(dev, "failed to xfer data\n");
+ goto out;
+ }
+ }
+
+out:
+ sifive_spi_clear_cs(spi);
+ return ret;
+}
+
+static void sifive_spi_set_speed(struct sifive_spi *spi, uint speed)
+{
+ u32 scale;
+
+ if (speed > spi->freq)
+ speed = spi->freq;
+
+ /* Cofigure max speed */
+ scale = (DIV_ROUND_UP(spi->freq >> 1, speed) - 1)
+ & SIFIVE_SPI_SCKDIV_DIV_MASK;
+ writel(scale, spi->regs + SIFIVE_SPI_REG_SCKDIV);
+}
+
+static void sifive_spi_set_mode(struct sifive_spi *spi, uint mode)
+{
+ u32 cr;
+
+ /* Switch clock mode bits */
+ cr = readl(spi->regs + SIFIVE_SPI_REG_SCKMODE) &
+ ~SIFIVE_SPI_SCKMODE_MODE_MASK;
+ if (mode & SPI_CPHA)
+ cr |= SIFIVE_SPI_SCKMODE_PHA;
+ if (mode & SPI_CPOL)
+ cr |= SIFIVE_SPI_SCKMODE_POL;
+
+ writel(cr, spi->regs + SIFIVE_SPI_REG_SCKMODE);
+}
+
+static int sifive_spi_setup(struct spi_device *spi_dev)
+{
+ struct sifive_spi *spi = to_sifive_spi(spi_dev->controller);
+
+ sifive_spi_set_mode(spi, spi_dev->mode);
+ sifive_spi_set_speed(spi, spi_dev->max_speed_hz);
+
+ return 0;
+}
+
+static void sifive_spi_init_hw(struct sifive_spi *spi)
+{
+ struct device_d *dev = spi->ctlr.dev;
+ u32 cs_bits;
+
+ /* probe the number of CS lines */
+ spi->cs_inactive = readl(spi->regs + SIFIVE_SPI_REG_CSDEF);
+ writel(0xffffffffU, spi->regs + SIFIVE_SPI_REG_CSDEF);
+ cs_bits = readl(spi->regs + SIFIVE_SPI_REG_CSDEF);
+ writel(spi->cs_inactive, spi->regs + SIFIVE_SPI_REG_CSDEF);
+ if (!cs_bits) {
+ dev_warn(dev, "Could not auto probe CS lines\n");
+ return;
+ }
+
+ spi->ctlr.num_chipselect = ilog2(cs_bits) + 1;
+ if (spi->ctlr.num_chipselect > SIFIVE_SPI_MAX_CS) {
+ dev_warn(dev, "Invalid number of spi slaves\n");
+ return;
+ }
+
+ /* Watermark interrupts are disabled by default */
+ writel(0, spi->regs + SIFIVE_SPI_REG_IE);
+
+ /* Default watermark FIFO threshold values */
+ writel(1, spi->regs + SIFIVE_SPI_REG_TXMARK);
+ writel(0, spi->regs + SIFIVE_SPI_REG_RXMARK);
+
+ /* Set CS/SCK Delays and Inactive Time to defaults */
+ writel(SIFIVE_SPI_DELAY0_CSSCK(1) | SIFIVE_SPI_DELAY0_SCKCS(1),
+ spi->regs + SIFIVE_SPI_REG_DELAY0);
+ writel(SIFIVE_SPI_DELAY1_INTERCS(1) | SIFIVE_SPI_DELAY1_INTERXFR(0),
+ spi->regs + SIFIVE_SPI_REG_DELAY1);
+
+ /* Exit specialized memory-mapped SPI flash mode */
+ writel(0, spi->regs + SIFIVE_SPI_REG_FCTRL);
+}
+
+static const struct spi_controller_mem_ops sifive_spi_mem_ops = {
+ .exec_op = sifive_spi_exec_op,
+};
+
+static void sifive_spi_dt_probe(struct sifive_spi *spi)
+{
+ struct device_node *node = spi->ctlr.dev->device_node;
+
+ spi->fifo_depth = SIFIVE_SPI_DEFAULT_DEPTH;
+ of_property_read_u32(node, "sifive,fifo-depth", &spi->fifo_depth);
+
+ spi->bits_per_word = SIFIVE_SPI_DEFAULT_BITS;
+ of_property_read_u32(node, "sifive,max-bits-per-word", &spi->bits_per_word);
+}
+
+static int sifive_spi_probe(struct device_d *dev)
+{
+ struct sifive_spi *spi;
+ struct resource *iores;
+ struct spi_controller *ctlr;
+ struct clk *clkdev;
+
+ iores = dev_request_mem_resource(dev, 0);
+ if (IS_ERR(iores))
+ return PTR_ERR(iores);
+
+ spi = xzalloc(sizeof(*spi));
+
+ spi->regs = IOMEM(iores->start);
+ if (!spi->regs)
+ return -ENODEV;
+
+ ctlr = &spi->ctlr;
+ ctlr->dev = dev;
+
+ ctlr->setup = sifive_spi_setup;
+ ctlr->transfer = sifive_spi_transfer;
+ ctlr->mem_ops = &sifive_spi_mem_ops;
+
+ ctlr->bus_num = -1;
+
+ spi_controller_set_devdata(ctlr, spi);
+
+ sifive_spi_dt_probe(spi);
+
+ clkdev = clk_get(dev, NULL);
+ if (IS_ERR(clkdev))
+ return PTR_ERR(clkdev);
+
+ spi->freq = clk_get_rate(clkdev);
+
+ /* init the sifive spi hw */
+ sifive_spi_init_hw(spi);
+
+ return spi_register_master(ctlr);
+}
+
+static const struct of_device_id sifive_spi_ids[] = {
+ { .compatible = "sifive,spi0" },
+ { /* sentinel */ }
+};
+
+static struct driver_d sifive_spi_driver = {
+ .name = "sifive_spi",
+ .probe = sifive_spi_probe,
+ .of_compatible = sifive_spi_ids,
+};
+coredevice_platform_driver(sifive_spi_driver);
--
2.34.1
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