board: arm: Add support for Broadcom BCM7445

Add support for loading U-Boot on the Broadcom 7445 SoC.  This port
assumes Broadcom's BOLT bootloader is acting as the second stage
bootloader, and U-Boot is acting as the third stage bootloader, loaded
as an ELF program by BOLT.

Signed-off-by: Thomas Fitzsimmons <fitzsim@fitzsim.org>
Cc: Stefan Roese <sr@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
diff --git a/drivers/spi/bcmstb_spi.c b/drivers/spi/bcmstb_spi.c
new file mode 100644
index 0000000..fb1dc46
--- /dev/null
+++ b/drivers/spi/bcmstb_spi.c
@@ -0,0 +1,439 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018  Cisco Systems, Inc.
+ *
+ * Author: Thomas Fitzsimmons <fitzsim@fitzsim.org>
+ */
+
+#include <asm/io.h>
+#include <command.h>
+#include <config.h>
+#include <dm.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <log.h>
+#include <malloc.h>
+#include <spi.h>
+#include <time.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define SPBR_MIN		8
+#define BITS_PER_WORD		8
+
+#define NUM_TXRAM		32
+#define NUM_RXRAM		32
+#define NUM_CDRAM		16
+
+/* hif_mspi register structure. */
+struct bcmstb_hif_mspi_regs {
+	u32 spcr0_lsb;		/* 0x000 */
+	u32 spcr0_msb;		/* 0x004 */
+	u32 spcr1_lsb;		/* 0x008 */
+	u32 spcr1_msb;		/* 0x00c */
+	u32 newqp;		/* 0x010 */
+	u32 endqp;		/* 0x014 */
+	u32 spcr2;		/* 0x018 */
+	u32 reserved0;		/* 0x01c */
+	u32 mspi_status;	/* 0x020 */
+	u32 cptqp;		/* 0x024 */
+	u32 spcr3;		/* 0x028 */
+	u32 revision;		/* 0x02c */
+	u32 reserved1[4];	/* 0x030 */
+	u32 txram[NUM_TXRAM];	/* 0x040 */
+	u32 rxram[NUM_RXRAM];	/* 0x0c0 */
+	u32 cdram[NUM_CDRAM];	/* 0x140 */
+	u32 write_lock;		/* 0x180 */
+};
+
+/* hif_mspi masks. */
+#define HIF_MSPI_SPCR2_CONT_AFTER_CMD_MASK	0x00000080
+#define HIF_MSPI_SPCR2_SPE_MASK			0x00000040
+#define HIF_MSPI_SPCR2_SPIFIE_MASK		0x00000020
+#define HIF_MSPI_WRITE_LOCK_WRITE_LOCK_MASK	0x00000001
+
+/* bspi offsets. */
+#define BSPI_MAST_N_BOOT_CTRL			0x008
+
+/* bspi_raf is not used in this driver. */
+
+/* hif_spi_intr2 offsets and masks. */
+#define HIF_SPI_INTR2_CPU_CLEAR			0x08
+#define HIF_SPI_INTR2_CPU_MASK_SET		0x10
+#define HIF_SPI_INTR2_CPU_MASK_CLEAR		0x14
+#define HIF_SPI_INTR2_CPU_SET_MSPI_DONE_MASK	0x00000020
+
+/* SPI transfer timeout in milliseconds. */
+#define HIF_MSPI_WAIT				10
+
+enum bcmstb_base_type {
+	HIF_MSPI,
+	BSPI,
+	HIF_SPI_INTR2,
+	CS_REG,
+	BASE_LAST,
+};
+
+struct bcmstb_spi_platdata {
+	void *base[4];
+};
+
+struct bcmstb_spi_priv {
+	struct bcmstb_hif_mspi_regs *regs;
+	void *bspi;
+	void *hif_spi_intr2;
+	void *cs_reg;
+	int default_cs;
+	int curr_cs;
+	uint tx_slot;
+	uint rx_slot;
+	u8 saved_cmd[NUM_CDRAM];
+	uint saved_cmd_len;
+	void *saved_din_addr;
+};
+
+static int bcmstb_spi_ofdata_to_platdata(struct udevice *bus)
+{
+	struct bcmstb_spi_platdata *plat = dev_get_platdata(bus);
+	const void *fdt = gd->fdt_blob;
+	int node = dev_of_offset(bus);
+	int ret = 0;
+	int i = 0;
+	struct fdt_resource resource = { 0 };
+	char *names[BASE_LAST] = { "hif_mspi", "bspi", "hif_spi_intr2",
+				   "cs_reg" };
+	const phys_addr_t defaults[BASE_LAST] = { BCMSTB_HIF_MSPI_BASE,
+						  BCMSTB_BSPI_BASE,
+						  BCMSTB_HIF_SPI_INTR2,
+						  BCMSTB_CS_REG };
+
+	for (i = 0; i < BASE_LAST; i++) {
+		plat->base[i] = (void *)defaults[i];
+
+		ret = fdt_get_named_resource(fdt, node, "reg", "reg-names",
+					     names[i], &resource);
+		if (ret) {
+			printf("%s: Assuming BCMSTB SPI %s address 0x0x%p\n",
+			       __func__, names[i], (void *)defaults[i]);
+		} else {
+			plat->base[i] = (void *)resource.start;
+			debug("BCMSTB SPI %s address: 0x0x%p\n",
+			      names[i], (void *)plat->base[i]);
+		}
+	}
+
+	return 0;
+}
+
+static void bcmstb_spi_hw_set_parms(struct bcmstb_spi_priv *priv)
+{
+	writel(SPBR_MIN, &priv->regs->spcr0_lsb);
+	writel(BITS_PER_WORD << 2 | SPI_MODE_3, &priv->regs->spcr0_msb);
+}
+
+static void bcmstb_spi_enable_interrupt(void *base, u32 mask)
+{
+	void *reg = base + HIF_SPI_INTR2_CPU_MASK_CLEAR;
+
+	writel(readl(reg) | mask, reg);
+	readl(reg);
+}
+
+static void bcmstb_spi_disable_interrupt(void *base, u32 mask)
+{
+	void *reg = base + HIF_SPI_INTR2_CPU_MASK_SET;
+
+	writel(readl(reg) | mask, reg);
+	readl(reg);
+}
+
+static void bcmstb_spi_clear_interrupt(void *base, u32 mask)
+{
+	void *reg = base + HIF_SPI_INTR2_CPU_CLEAR;
+
+	writel(readl(reg) | mask, reg);
+	readl(reg);
+}
+
+static int bcmstb_spi_probe(struct udevice *bus)
+{
+	struct bcmstb_spi_platdata *plat = dev_get_platdata(bus);
+	struct bcmstb_spi_priv *priv = dev_get_priv(bus);
+
+	priv->regs = plat->base[HIF_MSPI];
+	priv->bspi = plat->base[BSPI];
+	priv->hif_spi_intr2 = plat->base[HIF_SPI_INTR2];
+	priv->cs_reg = plat->base[CS_REG];
+	priv->default_cs = 0;
+	priv->curr_cs = -1;
+	priv->tx_slot = 0;
+	priv->rx_slot = 0;
+	memset(priv->saved_cmd, 0, NUM_CDRAM);
+	priv->saved_cmd_len = 0;
+	priv->saved_din_addr = NULL;
+
+	debug("spi_xfer: tx regs: 0x%p\n", &priv->regs->txram[0]);
+	debug("spi_xfer: rx regs: 0x%p\n", &priv->regs->rxram[0]);
+
+	/* Disable BSPI. */
+	writel(1, priv->bspi + BSPI_MAST_N_BOOT_CTRL);
+	readl(priv->bspi + BSPI_MAST_N_BOOT_CTRL);
+
+	/* Set up interrupts. */
+	bcmstb_spi_disable_interrupt(priv->hif_spi_intr2, 0xffffffff);
+	bcmstb_spi_clear_interrupt(priv->hif_spi_intr2, 0xffffffff);
+	bcmstb_spi_enable_interrupt(priv->hif_spi_intr2,
+				    HIF_SPI_INTR2_CPU_SET_MSPI_DONE_MASK);
+
+	/* Set up control registers. */
+	writel(0, &priv->regs->spcr1_lsb);
+	writel(0, &priv->regs->spcr1_msb);
+	writel(0, &priv->regs->newqp);
+	writel(0, &priv->regs->endqp);
+	writel(HIF_MSPI_SPCR2_SPIFIE_MASK, &priv->regs->spcr2);
+	writel(0, &priv->regs->spcr3);
+
+	bcmstb_spi_hw_set_parms(priv);
+
+	return 0;
+}
+
+static void bcmstb_spi_submit(struct bcmstb_spi_priv *priv, bool done)
+{
+	debug("WR NEWQP: %d\n", 0);
+	writel(0, &priv->regs->newqp);
+
+	debug("WR ENDQP: %d\n", priv->tx_slot - 1);
+	writel(priv->tx_slot - 1, &priv->regs->endqp);
+
+	if (done) {
+		debug("WR CDRAM[%d]: %02x\n", priv->tx_slot - 1,
+		      readl(&priv->regs->cdram[priv->tx_slot - 1]) & ~0x80);
+		writel(readl(&priv->regs->cdram[priv->tx_slot - 1]) & ~0x80,
+		       &priv->regs->cdram[priv->tx_slot - 1]);
+	}
+
+	/* Force chip select first time. */
+	if (priv->curr_cs != priv->default_cs) {
+		debug("spi_xfer: switching chip select to %d\n",
+		      priv->default_cs);
+		writel((readl(priv->cs_reg) & ~0xff) | (1 << priv->default_cs),
+		       priv->cs_reg);
+		readl(priv->cs_reg);
+		udelay(10);
+		priv->curr_cs = priv->default_cs;
+	}
+
+	debug("WR WRITE_LOCK: %02x\n", 1);
+	writel((readl(&priv->regs->write_lock) &
+		~HIF_MSPI_WRITE_LOCK_WRITE_LOCK_MASK) | 1,
+	       &priv->regs->write_lock);
+	readl(&priv->regs->write_lock);
+
+	debug("WR SPCR2: %02x\n",
+	      HIF_MSPI_SPCR2_SPIFIE_MASK |
+	      HIF_MSPI_SPCR2_SPE_MASK |
+	      HIF_MSPI_SPCR2_CONT_AFTER_CMD_MASK);
+	writel(HIF_MSPI_SPCR2_SPIFIE_MASK |
+	       HIF_MSPI_SPCR2_SPE_MASK |
+	       HIF_MSPI_SPCR2_CONT_AFTER_CMD_MASK,
+	       &priv->regs->spcr2);
+}
+
+static int bcmstb_spi_wait(struct bcmstb_spi_priv *priv)
+{
+	u32 start_time = get_timer(0);
+	u32 status = readl(&priv->regs->mspi_status);
+
+	while (!(status & 1)) {
+		if (get_timer(start_time) > HIF_MSPI_WAIT)
+			return -ETIMEDOUT;
+		status = readl(&priv->regs->mspi_status);
+	}
+
+	writel(readl(&priv->regs->mspi_status) & ~1, &priv->regs->mspi_status);
+	bcmstb_spi_clear_interrupt(priv->hif_spi_intr2,
+				   HIF_SPI_INTR2_CPU_SET_MSPI_DONE_MASK);
+
+	return 0;
+}
+
+static int bcmstb_spi_xfer(struct udevice *dev, unsigned int bitlen,
+			   const void *dout, void *din, unsigned long flags)
+{
+	uint len = bitlen / 8;
+	uint tx_len = len;
+	uint rx_len = len;
+	const u8 *out_bytes = (u8 *)dout;
+	u8 *in_bytes = (u8 *)din;
+	struct udevice *bus = dev_get_parent(dev);
+	struct bcmstb_spi_priv *priv = dev_get_priv(bus);
+	struct bcmstb_hif_mspi_regs *regs = priv->regs;
+
+	debug("spi_xfer: %d, t: 0x%p, r: 0x%p, f: %lx\n",
+	      len, dout, din, flags);
+	debug("spi_xfer: chip select: %x\n", readl(priv->cs_reg) & 0xff);
+	debug("spi_xfer: tx addr: 0x%p\n", &regs->txram[0]);
+	debug("spi_xfer: rx addr: 0x%p\n", &regs->rxram[0]);
+	debug("spi_xfer: cd addr: 0x%p\n", &regs->cdram[0]);
+
+	if (flags & SPI_XFER_END) {
+		debug("spi_xfer: clearing saved din address: 0x%p\n",
+		      priv->saved_din_addr);
+		priv->saved_din_addr = NULL;
+		priv->saved_cmd_len = 0;
+		memset(priv->saved_cmd, 0, NUM_CDRAM);
+	}
+
+	if (bitlen == 0)
+		return 0;
+
+	if (bitlen % 8) {
+		printf("%s: Non-byte-aligned transfer\n", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	if (flags & ~(SPI_XFER_BEGIN | SPI_XFER_END)) {
+		printf("%s: Unsupported flags: %lx\n", __func__, flags);
+		return -EOPNOTSUPP;
+	}
+
+	if (flags & SPI_XFER_BEGIN) {
+		priv->tx_slot = 0;
+		priv->rx_slot = 0;
+
+		if (out_bytes && len > NUM_CDRAM) {
+			printf("%s: Unable to save transfer\n", __func__);
+			return -EOPNOTSUPP;
+		}
+
+		if (out_bytes && !(flags & SPI_XFER_END)) {
+			/*
+			 * This is the start of a transmit operation
+			 * that will need repeating if the calling
+			 * code polls for the result.  Save it for
+			 * subsequent transmission.
+			 */
+			debug("spi_xfer: saving command: %x, %d\n",
+			      out_bytes[0], len);
+			priv->saved_cmd_len = len;
+			memcpy(priv->saved_cmd, out_bytes, priv->saved_cmd_len);
+		}
+	}
+
+	if (!(flags & (SPI_XFER_BEGIN | SPI_XFER_END))) {
+		if (priv->saved_din_addr == din) {
+			/*
+			 * The caller is polling for status.  Repeat
+			 * the last transmission.
+			 */
+			int ret = 0;
+
+			debug("spi_xfer: Making recursive call\n");
+			ret = bcmstb_spi_xfer(dev, priv->saved_cmd_len * 8,
+					      priv->saved_cmd, NULL,
+					      SPI_XFER_BEGIN);
+			if (ret) {
+				printf("%s: Recursive call failed\n", __func__);
+				return ret;
+			}
+		} else {
+			debug("spi_xfer: saving din address: 0x%p\n", din);
+			priv->saved_din_addr = din;
+		}
+	}
+
+	while (rx_len > 0) {
+		priv->rx_slot = priv->tx_slot;
+
+		while (priv->tx_slot < NUM_CDRAM && tx_len > 0) {
+			bcmstb_spi_hw_set_parms(priv);
+			debug("WR TXRAM[%d]: %02x\n", priv->tx_slot,
+			      out_bytes ? out_bytes[len - tx_len] : 0xff);
+			writel(out_bytes ? out_bytes[len - tx_len] : 0xff,
+			       &regs->txram[priv->tx_slot << 1]);
+			debug("WR CDRAM[%d]: %02x\n", priv->tx_slot, 0x8e);
+			writel(0x8e, &regs->cdram[priv->tx_slot]);
+			priv->tx_slot++;
+			tx_len--;
+			if (!in_bytes)
+				rx_len--;
+		}
+
+		debug("spi_xfer: early return clauses: %d, %d, %d\n",
+		      len <= NUM_CDRAM,
+		      !in_bytes,
+		      (flags & (SPI_XFER_BEGIN |
+				SPI_XFER_END)) == SPI_XFER_BEGIN);
+		if (len <= NUM_CDRAM &&
+		    !in_bytes &&
+		    (flags & (SPI_XFER_BEGIN | SPI_XFER_END)) == SPI_XFER_BEGIN)
+			return 0;
+
+		bcmstb_spi_submit(priv, tx_len == 0);
+
+		if (bcmstb_spi_wait(priv) == -ETIMEDOUT) {
+			printf("%s: Timed out\n", __func__);
+			return -ETIMEDOUT;
+		}
+
+		priv->tx_slot %= NUM_CDRAM;
+
+		if (in_bytes) {
+			while (priv->rx_slot < NUM_CDRAM && rx_len > 0) {
+				in_bytes[len - rx_len] =
+					readl(&regs->rxram[(priv->rx_slot << 1)
+							   + 1])
+					& 0xff;
+				debug("RD RXRAM[%d]: %02x\n",
+				      priv->rx_slot, in_bytes[len - rx_len]);
+				priv->rx_slot++;
+				rx_len--;
+			}
+		}
+	}
+
+	if (flags & SPI_XFER_END) {
+		debug("WR WRITE_LOCK: %02x\n", 0);
+		writel((readl(&priv->regs->write_lock) &
+			~HIF_MSPI_WRITE_LOCK_WRITE_LOCK_MASK) | 0,
+		       &priv->regs->write_lock);
+		readl(&priv->regs->write_lock);
+	}
+
+	return 0;
+}
+
+static int bcmstb_spi_set_speed(struct udevice *dev, uint speed)
+{
+	return 0;
+}
+
+static int bcmstb_spi_set_mode(struct udevice *dev, uint mode)
+{
+	return 0;
+}
+
+static const struct dm_spi_ops bcmstb_spi_ops = {
+	.xfer		= bcmstb_spi_xfer,
+	.set_speed	= bcmstb_spi_set_speed,
+	.set_mode	= bcmstb_spi_set_mode,
+};
+
+static const struct udevice_id bcmstb_spi_id[] = {
+	{ .compatible = "brcm,spi-brcmstb" },
+	{ }
+};
+
+U_BOOT_DRIVER(bcmstb_spi) = {
+	.name				= "bcmstb_spi",
+	.id				= UCLASS_SPI,
+	.of_match			= bcmstb_spi_id,
+	.ops				= &bcmstb_spi_ops,
+	.ofdata_to_platdata		= bcmstb_spi_ofdata_to_platdata,
+	.probe				= bcmstb_spi_probe,
+	.platdata_auto_alloc_size	= sizeof(struct bcmstb_spi_platdata),
+	.priv_auto_alloc_size		= sizeof(struct bcmstb_spi_priv),
+};