--- /dev/null
+/*
+ * Designware master SPI core controller driver
+ *
+ * Copyright (C) 2014 Stefan Roese <sr@denx.de>
+ *
+ * Very loosly based on the Linux driver version which is:
+ * Copyright (c) 2009, Intel Corporation.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <malloc.h>
+#include <spi.h>
+#include <fdtdec.h>
+#include <linux/compat.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* 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_TXFLTR 0x18
+#define DW_SPI_RXFLTR 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
+
+/* Bit fields in CTRLR0 */
+#define SPI_DFS_OFFSET 0
+
+#define SPI_FRF_OFFSET 4
+#define SPI_FRF_SPI 0x0
+#define SPI_FRF_SSP 0x1
+#define SPI_FRF_MICROWIRE 0x2
+#define SPI_FRF_RESV 0x3
+
+#define SPI_MODE_OFFSET 6
+#define SPI_SCPH_OFFSET 6
+#define SPI_SCOL_OFFSET 7
+
+#define SPI_TMOD_OFFSET 8
+#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 10
+#define SPI_SRL_OFFSET 11
+#define SPI_CFS_OFFSET 12
+
+/* Bit fields in SR, 7 bits */
+#define SR_MASK 0x7f /* cover 7 bits */
+#define SR_BUSY (1 << 0)
+#define SR_TF_NOT_FULL (1 << 1)
+#define SR_TF_EMPT (1 << 2)
+#define SR_RF_NOT_EMPT (1 << 3)
+#define SR_RF_FULL (1 << 4)
+#define SR_TX_ERR (1 << 5)
+#define SR_DCOL (1 << 6)
+
+#define RX_TIMEOUT 1000
+
+struct dw_spi_platdata {
+ s32 frequency; /* Default clock frequency, -1 for none */
+ void __iomem *regs;
+};
+
+struct dw_spi_priv {
+ void __iomem *regs;
+ unsigned int freq; /* Default frequency */
+ unsigned int mode;
+
+ int bits_per_word;
+ u8 cs; /* chip select pin */
+ u8 n_bytes; /* current is a 1/2/4 byte op */
+ u8 tmode; /* TR/TO/RO/EEPROM */
+ u8 type; /* SPI/SSP/MicroWire */
+ int len;
+
+ u32 fifo_len; /* depth of the FIFO buffer */
+ void *tx;
+ void *tx_end;
+ void *rx;
+ void *rx_end;
+};
+
+static inline u32 dw_readl(struct dw_spi_priv *priv, u32 offset)
+{
+ return __raw_readl(priv->regs + offset);
+}
+
+static inline void dw_writel(struct dw_spi_priv *priv, u32 offset, u32 val)
+{
+ __raw_writel(val, priv->regs + offset);
+}
+
+static inline u16 dw_readw(struct dw_spi_priv *priv, u32 offset)
+{
+ return __raw_readw(priv->regs + offset);
+}
+
+static inline void dw_writew(struct dw_spi_priv *priv, u32 offset, u16 val)
+{
+ __raw_writew(val, priv->regs + offset);
+}
+
+static int dw_spi_ofdata_to_platdata(struct udevice *bus)
+{
+ struct dw_spi_platdata *plat = bus->platdata;
+ const void *blob = gd->fdt_blob;
+ int node = bus->of_offset;
+
+ plat->regs = (struct dw_spi *)fdtdec_get_addr(blob, node, "reg");
+
+ /* Use 500KHz as a suitable default */
+ plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
+ 500000);
+ debug("%s: regs=%p max-frequency=%d\n", __func__, plat->regs,
+ plat->frequency);
+
+ return 0;
+}
+
+static inline void spi_enable_chip(struct dw_spi_priv *priv, int enable)
+{
+ dw_writel(priv, DW_SPI_SSIENR, (enable ? 1 : 0));
+}
+
+/* Restart the controller, disable all interrupts, clean rx fifo */
+static void spi_hw_init(struct dw_spi_priv *priv)
+{
+ spi_enable_chip(priv, 0);
+ dw_writel(priv, DW_SPI_IMR, 0xff);
+ spi_enable_chip(priv, 1);
+
+ /*
+ * Try to detect the FIFO depth if not set by interface driver,
+ * the depth could be from 2 to 256 from HW spec
+ */
+ if (!priv->fifo_len) {
+ u32 fifo;
+
+ for (fifo = 2; fifo <= 257; fifo++) {
+ dw_writew(priv, DW_SPI_TXFLTR, fifo);
+ if (fifo != dw_readw(priv, DW_SPI_TXFLTR))
+ break;
+ }
+
+ priv->fifo_len = (fifo == 257) ? 0 : fifo;
+ dw_writew(priv, DW_SPI_TXFLTR, 0);
+ }
+ debug("%s: fifo_len=%d\n", __func__, priv->fifo_len);
+}
+
+static int dw_spi_probe(struct udevice *bus)
+{
+ struct dw_spi_platdata *plat = dev_get_platdata(bus);
+ struct dw_spi_priv *priv = dev_get_priv(bus);
+
+ priv->regs = plat->regs;
+ priv->freq = plat->frequency;
+
+ /* Currently only bits_per_word == 8 supported */
+ priv->bits_per_word = 8;
+ priv->n_bytes = 1;
+
+ priv->tmode = 0; /* Tx & Rx */
+
+ /* Basic HW init */
+ spi_hw_init(priv);
+
+ return 0;
+}
+
+/* Return the max entries we can fill into tx fifo */
+static inline u32 tx_max(struct dw_spi_priv *priv)
+{
+ u32 tx_left, tx_room, rxtx_gap;
+
+ tx_left = (priv->tx_end - priv->tx) / priv->n_bytes;
+ tx_room = priv->fifo_len - dw_readw(priv, DW_SPI_TXFLR);
+
+ /*
+ * Another concern is about the tx/rx mismatch, we
+ * though to use (priv->fifo_len - rxflr - txflr) as
+ * one maximum value for tx, but it doesn't cover the
+ * data which is out of tx/rx fifo and inside the
+ * shift registers. So a control from sw point of
+ * view is taken.
+ */
+ rxtx_gap = ((priv->rx_end - priv->rx) - (priv->tx_end - priv->tx)) /
+ priv->n_bytes;
+
+ return min3(tx_left, tx_room, (u32)(priv->fifo_len - rxtx_gap));
+}
+
+/* Return the max entries we should read out of rx fifo */
+static inline u32 rx_max(struct dw_spi_priv *priv)
+{
+ u32 rx_left = (priv->rx_end - priv->rx) / priv->n_bytes;
+
+ return min_t(u32, rx_left, dw_readw(priv, DW_SPI_RXFLR));
+}
+
+static void dw_writer(struct dw_spi_priv *priv)
+{
+ u32 max = tx_max(priv);
+ u16 txw = 0;
+
+ while (max--) {
+ /* Set the tx word if the transfer's original "tx" is not null */
+ if (priv->tx_end - priv->len) {
+ if (priv->n_bytes == 1)
+ txw = *(u8 *)(priv->tx);
+ else
+ txw = *(u16 *)(priv->tx);
+ }
+ dw_writew(priv, DW_SPI_DR, txw);
+ debug("%s: tx=0x%02x\n", __func__, txw);
+ priv->tx += priv->n_bytes;
+ }
+}
+
+static int dw_reader(struct dw_spi_priv *priv)
+{
+ unsigned start = get_timer(0);
+ u32 max;
+ u16 rxw;
+
+ /* Wait for rx data to be ready */
+ while (rx_max(priv) == 0) {
+ if (get_timer(start) > RX_TIMEOUT)
+ return -ETIMEDOUT;
+ }
+
+ max = rx_max(priv);
+
+ while (max--) {
+ rxw = dw_readw(priv, DW_SPI_DR);
+ debug("%s: rx=0x%02x\n", __func__, rxw);
+ /* Care rx only if the transfer's original "rx" is not null */
+ if (priv->rx_end - priv->len) {
+ if (priv->n_bytes == 1)
+ *(u8 *)(priv->rx) = rxw;
+ else
+ *(u16 *)(priv->rx) = rxw;
+ }
+ priv->rx += priv->n_bytes;
+ }
+
+ return 0;
+}
+
+static int poll_transfer(struct dw_spi_priv *priv)
+{
+ int ret;
+
+ do {
+ dw_writer(priv);
+ ret = dw_reader(priv);
+ if (ret < 0)
+ return ret;
+ } while (priv->rx_end > priv->rx);
+
+ return 0;
+}
+
+static int dw_spi_xfer(struct udevice *dev, unsigned int bitlen,
+ const void *dout, void *din, unsigned long flags)
+{
+ struct udevice *bus = dev->parent;
+ struct dw_spi_priv *priv = dev_get_priv(bus);
+ const u8 *tx = dout;
+ u8 *rx = din;
+ int ret = 0;
+ u32 cr0 = 0;
+ u8 bits = 0;
+ u32 cs;
+
+ /* spi core configured to do 8 bit transfers */
+ if (bitlen % 8) {
+ debug("Non byte aligned SPI transfer.\n");
+ return -1;
+ }
+
+ bits = priv->bits_per_word;
+ priv->n_bytes = bits >> 3;
+ cr0 = (bits - 1) | (priv->type << SPI_FRF_OFFSET) |
+ (priv->mode << SPI_MODE_OFFSET) |
+ (priv->tmode << SPI_TMOD_OFFSET);
+
+ if (rx && tx)
+ priv->tmode = SPI_TMOD_TR;
+ else if (rx)
+ priv->tmode = SPI_TMOD_RO;
+ else
+ priv->tmode = SPI_TMOD_TO;
+
+ cr0 &= ~SPI_TMOD_MASK;
+ cr0 |= (priv->tmode << SPI_TMOD_OFFSET);
+
+ priv->len = bitlen / 8;
+ debug("%s: rx=%p tx=%p len=%d [bytes]\n", __func__, rx, tx, priv->len);
+
+ priv->tx = (void *)tx;
+ priv->tx_end = priv->tx + priv->len;
+ priv->rx = rx;
+ priv->rx_end = priv->rx + priv->len;
+
+ /* Disable controller before writing control registers */
+ spi_enable_chip(priv, 0);
+
+ debug("%s: cr0=%08x\n", __func__, cr0);
+ /* Reprogram cr0 only if changed */
+ if (dw_readw(priv, DW_SPI_CTRL0) != cr0)
+ dw_writew(priv, DW_SPI_CTRL0, cr0);
+
+ /*
+ * Configure the desired SS (slave select 0...3) in the controller
+ * The DW SPI controller will activate and deactivate this CS
+ * automatically. So no cs_activate() etc is needed in this driver.
+ */
+ cs = spi_chip_select(dev);
+ dw_writel(priv, DW_SPI_SER, 1 << cs);
+
+ /* Enable controller after writing control registers */
+ spi_enable_chip(priv, 1);
+
+ /* Start transfer in a polling loop */
+ ret = poll_transfer(priv);
+
+ return ret;
+}
+
+static int dw_spi_set_speed(struct udevice *bus, uint speed)
+{
+ struct dw_spi_platdata *plat = bus->platdata;
+ struct dw_spi_priv *priv = dev_get_priv(bus);
+ u16 clk_div;
+
+ if (speed > plat->frequency)
+ speed = plat->frequency;
+
+ /* Disable controller before writing control registers */
+ spi_enable_chip(priv, 0);
+
+ /* clk_div doesn't support odd number */
+ clk_div = CONFIG_DW_SPI_REF_CLK / speed;
+ clk_div = (clk_div + 1) & 0xfffe;
+ dw_writel(priv, DW_SPI_BAUDR, clk_div);
+
+ /* Enable controller after writing control registers */
+ spi_enable_chip(priv, 1);
+
+ priv->freq = speed;
+ debug("%s: regs=%p speed=%d clk_div=%d\n", __func__, priv->regs,
+ priv->freq, clk_div);
+
+ return 0;
+}
+
+static int dw_spi_set_mode(struct udevice *bus, uint mode)
+{
+ struct dw_spi_priv *priv = dev_get_priv(bus);
+
+ /*
+ * Can't set mode yet. Since this depends on if rx, tx, or
+ * rx & tx is requested. So we have to defer this to the
+ * real transfer function.
+ */
+ priv->mode = mode;
+ debug("%s: regs=%p, mode=%d\n", __func__, priv->regs, priv->mode);
+
+ return 0;
+}
+
+static const struct dm_spi_ops dw_spi_ops = {
+ .xfer = dw_spi_xfer,
+ .set_speed = dw_spi_set_speed,
+ .set_mode = dw_spi_set_mode,
+ /*
+ * cs_info is not needed, since we require all chip selects to be
+ * in the device tree explicitly
+ */
+};
+
+static const struct udevice_id dw_spi_ids[] = {
+ { .compatible = "snps,dw-spi-mmio" },
+ { }
+};
+
+U_BOOT_DRIVER(dw_spi) = {
+ .name = "dw_spi",
+ .id = UCLASS_SPI,
+ .of_match = dw_spi_ids,
+ .ops = &dw_spi_ops,
+ .ofdata_to_platdata = dw_spi_ofdata_to_platdata,
+ .platdata_auto_alloc_size = sizeof(struct dw_spi_platdata),
+ .priv_auto_alloc_size = sizeof(struct dw_spi_priv),
+ .per_child_auto_alloc_size = sizeof(struct spi_slave),
+ .probe = dw_spi_probe,
+};
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