--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018 SiFive, Inc.
+ * Copyright 2019 Bhargav Shah <bhargavshah1988@gmail.com>
+ *
+ * SiFive SPI controller driver (master mode only)
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <malloc.h>
+#include <spi.h>
+#include <asm/io.h>
+#include <linux/log2.h>
+#include <clk.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)
+
+struct sifive_spi {
+ void *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;
+ u32 num_cs;
+};
+
+static void sifive_spi_prep_device(struct sifive_spi *spi,
+ struct dm_spi_slave_platdata *slave)
+{
+ /* Update the chip select polarity */
+ if (slave->mode & SPI_CS_HIGH)
+ spi->cs_inactive &= ~BIT(slave->cs);
+ else
+ spi->cs_inactive |= BIT(slave->cs);
+ writel(spi->cs_inactive, spi->regs + SIFIVE_SPI_REG_CSDEF);
+
+ /* Select the correct device */
+ writel(slave->cs, spi->regs + SIFIVE_SPI_REG_CSID);
+}
+
+static int sifive_spi_set_cs(struct sifive_spi *spi,
+ struct dm_spi_slave_platdata *slave)
+{
+ u32 cs_mode = SIFIVE_SPI_CSMODE_MODE_HOLD;
+
+ if (slave->mode & SPI_CS_HIGH)
+ cs_mode = SIFIVE_SPI_CSMODE_MODE_AUTO;
+
+ writel(cs_mode, spi->regs + SIFIVE_SPI_REG_CSMODE);
+
+ return 0;
+}
+
+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,
+ bool is_rx_xfer,
+ struct dm_spi_slave_platdata *slave)
+{
+ 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 (slave->mode & SPI_LSB_FIRST)
+ cr |= SIFIVE_SPI_FMT_ENDIAN;
+
+ /* Number of wires ? */
+ cr &= ~SIFIVE_SPI_FMT_PROTO_MASK;
+ if ((slave->mode & SPI_TX_QUAD) || (slave->mode & SPI_RX_QUAD))
+ cr |= SIFIVE_SPI_FMT_PROTO_QUAD;
+ else if ((slave->mode & SPI_TX_DUAL) || (slave->mode & SPI_RX_DUAL))
+ cr |= SIFIVE_SPI_FMT_PROTO_DUAL;
+ else
+ cr |= SIFIVE_SPI_FMT_PROTO_SINGLE;
+
+ /* SPI direction in/out ? */
+ cr &= ~SIFIVE_SPI_FMT_DIR;
+ if (!is_rx_xfer)
+ 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_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct udevice *bus = dev->parent;
+ struct sifive_spi *spi = dev_get_priv(bus);
+ struct dm_spi_slave_platdata *slave = dev_get_parent_platdata(dev);
+ const unsigned char *tx_ptr = dout;
+ u8 *rx_ptr = din;
+ u32 remaining_len;
+ int ret;
+
+ if (flags & SPI_XFER_BEGIN) {
+ sifive_spi_prep_device(spi, slave);
+
+ ret = sifive_spi_set_cs(spi, slave);
+ if (ret)
+ return ret;
+ }
+
+ sifive_spi_prep_transfer(spi, true, slave);
+
+ remaining_len = bitlen / 8;
+
+ while (remaining_len) {
+ int n_words, tx_words, rx_words;
+
+ n_words = min(remaining_len, spi->fifo_depth);
+
+ /* Enqueue n_words for transmission */
+ if (tx_ptr) {
+ for (tx_words = 0; tx_words < n_words; ++tx_words) {
+ sifive_spi_tx(spi, tx_ptr);
+ sifive_spi_rx(spi, NULL);
+ tx_ptr++;
+ }
+ }
+
+ /* Read out all the data from the RX FIFO */
+ if (rx_ptr) {
+ for (rx_words = 0; rx_words < n_words; ++rx_words) {
+ sifive_spi_tx(spi, NULL);
+ sifive_spi_rx(spi, rx_ptr);
+ rx_ptr++;
+ }
+ }
+
+ remaining_len -= n_words;
+ }
+
+ if (flags & SPI_XFER_END)
+ sifive_spi_clear_cs(spi);
+
+ return 0;
+}
+
+static int sifive_spi_set_speed(struct udevice *bus, uint speed)
+{
+ struct sifive_spi *spi = dev_get_priv(bus);
+ 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);
+
+ return 0;
+}
+
+static int sifive_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct sifive_spi *spi = dev_get_priv(bus);
+ 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);
+
+ return 0;
+}
+
+static int sifive_spi_cs_info(struct udevice *bus, uint cs,
+ struct spi_cs_info *info)
+{
+ struct sifive_spi *spi = dev_get_priv(bus);
+
+ if (cs >= spi->num_cs)
+ return -EINVAL;
+
+ return 0;
+}
+
+static void sifive_spi_init_hw(struct sifive_spi *spi)
+{
+ 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) {
+ printf("Could not auto probe CS lines\n");
+ return;
+ }
+
+ spi->num_cs = ilog2(cs_bits) + 1;
+ if (spi->num_cs > SIFIVE_SPI_MAX_CS) {
+ printf("Invalid number of spi slaves\n");
+ return;
+ }
+
+ /* Watermark interrupts are disabled by default */
+ writel(0, spi->regs + SIFIVE_SPI_REG_IE);
+
+ /* 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 int sifive_spi_probe(struct udevice *bus)
+{
+ struct sifive_spi *spi = dev_get_priv(bus);
+ struct clk clkdev;
+ int ret;
+
+ spi->regs = (void *)(ulong)dev_remap_addr(bus);
+ if (!spi->regs)
+ return -ENODEV;
+
+ spi->fifo_depth = dev_read_u32_default(bus,
+ "sifive,fifo-depth",
+ SIFIVE_SPI_DEFAULT_DEPTH);
+
+ spi->bits_per_word = dev_read_u32_default(bus,
+ "sifive,max-bits-per-word",
+ SIFIVE_SPI_DEFAULT_BITS);
+
+ ret = clk_get_by_index(bus, 0, &clkdev);
+ if (ret)
+ return ret;
+ spi->freq = clk_get_rate(&clkdev);
+
+ /* init the sifive spi hw */
+ sifive_spi_init_hw(spi);
+
+ return 0;
+}
+
+static const struct dm_spi_ops sifive_spi_ops = {
+ .xfer = sifive_spi_xfer,
+ .set_speed = sifive_spi_set_speed,
+ .set_mode = sifive_spi_set_mode,
+ .cs_info = sifive_spi_cs_info,
+};
+
+static const struct udevice_id sifive_spi_ids[] = {
+ { .compatible = "sifive,spi0" },
+ { }
+};
+
+U_BOOT_DRIVER(sifive_spi) = {
+ .name = "sifive_spi",
+ .id = UCLASS_SPI,
+ .of_match = sifive_spi_ids,
+ .ops = &sifive_spi_ops,
+ .priv_auto_alloc_size = sizeof(struct sifive_spi),
+ .probe = sifive_spi_probe,
+};
projects / oweals / u-boot.git / commitdiff