drivers: Add iproc spi driver

Add iproc spi driver

Change-Id: I652efab1efd9c487974dae9cb9d98b9b8e3759c4
Signed-off-by: Sheetal Tigadoli <sheetal.tigadoli@broadcom.com>
diff --git a/drivers/brcm/spi/iproc_qspi.c b/drivers/brcm/spi/iproc_qspi.c
new file mode 100644
index 0000000..4c533d5
--- /dev/null
+++ b/drivers/brcm/spi/iproc_qspi.c
@@ -0,0 +1,317 @@
+/*
+ * Copyright (c) 2017 - 2020, Broadcom
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <string.h>
+
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <endian.h>
+#include <lib/mmio.h>
+
+#include <platform_def.h>
+#include <spi.h>
+
+#include "iproc_qspi.h"
+
+struct bcmspi_priv spi_cfg;
+
+/* Redefined by platform to force appropriate information */
+#pragma weak plat_spi_init
+int plat_spi_init(uint32_t *max_hz)
+{
+	return 0;
+}
+
+/* Initialize & setup iproc qspi controller */
+int iproc_qspi_setup(uint32_t bus, uint32_t cs, uint32_t max_hz, uint32_t mode)
+{
+	struct bcmspi_priv *priv = NULL;
+	uint32_t spbr;
+
+	priv = &spi_cfg;
+	priv->spi_mode = mode;
+	priv->state = QSPI_STATE_DISABLED;
+	priv->bspi_hw = QSPI_BSPI_MODE_REG_BASE;
+	priv->mspi_hw = QSPI_MSPI_MODE_REG_BASE;
+
+	/* Initialize clock and platform specific */
+	if (plat_spi_init(&max_hz) != 0)
+		return -1;
+
+	priv->max_hz = max_hz;
+
+	/* MSPI: Basic hardware initialization */
+	mmio_write_32(priv->mspi_hw + MSPI_SPCR1_LSB_REG, 0);
+	mmio_write_32(priv->mspi_hw + MSPI_SPCR1_MSB_REG, 0);
+	mmio_write_32(priv->mspi_hw + MSPI_NEWQP_REG, 0);
+	mmio_write_32(priv->mspi_hw + MSPI_ENDQP_REG, 0);
+	mmio_write_32(priv->mspi_hw + MSPI_SPCR2_REG, 0);
+
+	/* MSPI: SCK configuration */
+	spbr = (QSPI_AXI_CLK - 1) / (2 * priv->max_hz) + 1;
+	spbr = MIN(spbr, SPBR_DIV_MAX);
+	spbr = MAX(spbr, SPBR_DIV_MIN);
+	mmio_write_32(priv->mspi_hw + MSPI_SPCR0_LSB_REG, spbr);
+
+	/* MSPI: Mode configuration (8 bits by default) */
+	priv->mspi_16bit = 0;
+	mmio_write_32(priv->mspi_hw + MSPI_SPCR0_MSB_REG,
+		      BIT(MSPI_SPCR0_MSB_REG_MSTR_SHIFT) |		/* Master */
+		      MSPI_SPCR0_MSB_REG_16_BITS_PER_WD_SHIFT |		/* 16 bits per word */
+		      (priv->spi_mode & MSPI_SPCR0_MSB_REG_MODE_MASK));	/* mode: CPOL / CPHA */
+
+	/* Display bus info */
+	VERBOSE("SPI: SPCR0_LSB: 0x%x\n",
+		mmio_read_32(priv->mspi_hw + MSPI_SPCR0_LSB_REG));
+	VERBOSE("SPI: SPCR0_MSB: 0x%x\n",
+		mmio_read_32(priv->mspi_hw + MSPI_SPCR0_MSB_REG));
+	VERBOSE("SPI: SPCR1_LSB: 0x%x\n",
+		mmio_read_32(priv->mspi_hw + MSPI_SPCR1_LSB_REG));
+	VERBOSE("SPI: SPCR1_MSB: 0x%x\n",
+		mmio_read_32(priv->mspi_hw + MSPI_SPCR1_MSB_REG));
+	VERBOSE("SPI: SPCR2: 0x%x\n",
+		mmio_read_32(priv->mspi_hw + MSPI_SPCR2_REG));
+	VERBOSE("SPI: CLK: %d\n", priv->max_hz);
+
+	return 0;
+}
+
+void bcmspi_enable_bspi(struct bcmspi_priv *priv)
+{
+	if (priv->state != QSPI_STATE_BSPI) {
+		/* Switch to BSPI */
+		mmio_write_32(priv->bspi_hw + BSPI_MAST_N_BOOT_CTRL_REG, 0);
+
+		priv->state = QSPI_STATE_BSPI;
+	}
+}
+
+static int bcmspi_disable_bspi(struct bcmspi_priv *priv)
+{
+	uint32_t retry;
+
+	if (priv->state == QSPI_STATE_MSPI)
+		return 0;
+
+	/* Switch to MSPI if not yet */
+	if ((mmio_read_32(priv->bspi_hw + BSPI_MAST_N_BOOT_CTRL_REG) &
+	     MSPI_CTRL_MASK) == 0) {
+		retry = QSPI_RETRY_COUNT_US_MAX;
+		do {
+			if ((mmio_read_32(
+				priv->bspi_hw + BSPI_BUSY_STATUS_REG) &
+				BSPI_BUSY_MASK) == 0) {
+				mmio_write_32(priv->bspi_hw +
+				       BSPI_MAST_N_BOOT_CTRL_REG,
+				       MSPI_CTRL_MASK);
+				udelay(1);
+				break;
+			}
+			udelay(1);
+		} while (retry--);
+
+		if ((mmio_read_32(priv->bspi_hw + BSPI_MAST_N_BOOT_CTRL_REG) &
+		     MSPI_CTRL_MASK) != MSPI_CTRL_MASK) {
+			ERROR("QSPI: Switching to QSPI error.\n");
+			return -1;
+		}
+	}
+
+	/* Update state */
+	priv->state = QSPI_STATE_MSPI;
+
+	return 0;
+}
+
+int iproc_qspi_claim_bus(void)
+{
+	struct bcmspi_priv *priv = &spi_cfg;
+
+	/* Switch to MSPI by default */
+	if (bcmspi_disable_bspi(priv) != 0)
+		return -1;
+
+	return 0;
+}
+
+void iproc_qspi_release_bus(void)
+{
+	struct bcmspi_priv *priv = &spi_cfg;
+
+	/* Switch to BSPI by default */
+	bcmspi_enable_bspi(priv);
+}
+
+static int mspi_xfer(struct bcmspi_priv *priv, uint32_t bytes,
+		     const uint8_t *tx, uint8_t *rx, uint32_t flag)
+{
+	uint32_t retry;
+	uint32_t mode = CDRAM_PCS0;
+
+	if (flag & SPI_XFER_QUAD) {
+		mode |= CDRAM_QUAD_MODE;
+		VERBOSE("SPI: QUAD mode\n");
+
+		if (!tx) {
+			VERBOSE("SPI: 4 lane input\n");
+			mode |= CDRAM_RBIT_INPUT;
+		}
+	}
+
+	/* Use 8-bit queue for odd-bytes transfer */
+	if (bytes & 1)
+		priv->mspi_16bit = 0;
+	else {
+		priv->mspi_16bit = 1;
+		mode |= CDRAM_BITS_EN;
+	}
+
+	while (bytes) {
+		uint32_t chunk;
+		uint32_t queues;
+		uint32_t i;
+
+		/* Separate code for 16bit and 8bit transfers for performance */
+		if (priv->mspi_16bit) {
+			VERBOSE("SPI: 16 bits xfer\n");
+			/* Determine how many bytes to process this time */
+			chunk = MIN(bytes, NUM_CDRAM_BYTES * 2);
+			queues = (chunk - 1) / 2 + 1;
+			bytes -= chunk;
+
+			/* Fill CDRAMs */
+			for (i = 0; i < queues; i++)
+				mmio_write_32(priv->mspi_hw + MSPI_CDRAM_REG +
+					      (i << 2), mode | CDRAM_CONT);
+
+			/* Fill TXRAMs */
+			for (i = 0; i < chunk; i++)
+				if (tx)
+					mmio_write_32(priv->mspi_hw +
+						MSPI_TXRAM_REG +
+						(i << 2), tx[i]);
+		} else {
+			VERBOSE("SPI: 8 bits xfer\n");
+			/* Determine how many bytes to process this time */
+			chunk = MIN(bytes, NUM_CDRAM_BYTES);
+			queues = chunk;
+			bytes -= chunk;
+
+			/* Fill CDRAMs and TXRAMS */
+			for (i = 0; i < chunk; i++) {
+				mmio_write_32(priv->mspi_hw + MSPI_CDRAM_REG +
+					      (i << 2), mode | CDRAM_CONT);
+				if (tx)
+					mmio_write_32(priv->mspi_hw +
+						MSPI_TXRAM_REG +
+						(i << 3), tx[i]);
+			}
+		}
+
+		/* Advance pointers */
+		if (tx)
+			tx += chunk;
+
+		/* Setup queue pointers */
+		mmio_write_32(priv->mspi_hw + MSPI_NEWQP_REG, 0);
+		mmio_write_32(priv->mspi_hw + MSPI_ENDQP_REG, queues - 1);
+
+		/* Remove CONT on the last byte command */
+		if (bytes == 0 && (flag & SPI_XFER_END))
+			mmio_write_32(priv->mspi_hw + MSPI_CDRAM_REG +
+				      ((queues - 1) << 2), mode);
+
+		/* Kick off */
+		mmio_write_32(priv->mspi_hw + MSPI_STATUS_REG, 0);
+		if (bytes == 0 && (flag & SPI_XFER_END))
+			mmio_write_32(priv->mspi_hw + MSPI_SPCR2_REG, MSPI_SPE);
+		else
+			mmio_write_32(priv->mspi_hw + MSPI_SPCR2_REG,
+				      MSPI_SPE | MSPI_CONT_AFTER_CMD);
+
+		/* Wait for completion */
+		retry = QSPI_RETRY_COUNT_US_MAX;
+		do {
+			if (mmio_read_32(priv->mspi_hw + MSPI_STATUS_REG) &
+			    MSPI_CMD_COMPLETE_MASK)
+				break;
+			udelay(1);
+		} while (retry--);
+
+		if ((mmio_read_32(priv->mspi_hw + MSPI_STATUS_REG) &
+		     MSPI_CMD_COMPLETE_MASK) == 0) {
+			ERROR("SPI: Completion timeout.\n");
+			return -1;
+		}
+
+		/* Read data out */
+		if (rx) {
+			if (priv->mspi_16bit) {
+				for (i = 0; i < chunk; i++) {
+					rx[i] = mmio_read_32(priv->mspi_hw +
+							MSPI_RXRAM_REG +
+						       (i << 2))
+						& 0xff;
+				}
+			} else {
+				for (i = 0; i < chunk; i++) {
+					rx[i] = mmio_read_32(priv->mspi_hw +
+						       MSPI_RXRAM_REG +
+						       (((i << 1) + 1) << 2))
+						& 0xff;
+				}
+			}
+			rx += chunk;
+		}
+	}
+
+	return 0;
+}
+
+int iproc_qspi_xfer(uint32_t bitlen,
+		    const void *dout, void *din, unsigned long flags)
+{
+	struct bcmspi_priv *priv;
+	const uint8_t *tx = dout;
+	uint8_t *rx = din;
+	uint32_t bytes = bitlen / 8;
+	int ret = 0;
+
+	priv = &spi_cfg;
+
+	if (priv->state == QSPI_STATE_DISABLED) {
+		ERROR("QSPI: state disabled\n");
+		return -1;
+	}
+
+	/* we can only do 8 bit transfers */
+	if (bitlen % 8) {
+		ERROR("QSPI: Only support 8 bit transfers (requested %d)\n",
+			bitlen);
+		return -1;
+	}
+
+	/* MSPI: Enable write lock at the beginning */
+	if (flags & SPI_XFER_BEGIN) {
+		/* Switch to MSPI if not yet */
+		if (bcmspi_disable_bspi(priv) != 0) {
+			ERROR("QSPI: Switch to MSPI failed\n");
+			return -1;
+		}
+
+		mmio_write_32(priv->mspi_hw + MSPI_WRITE_LOCK_REG, 1);
+	}
+
+	/* MSPI: Transfer it */
+	if (bytes)
+		ret = mspi_xfer(priv, bytes, tx, rx, flags);
+
+	/* MSPI: Disable write lock if it's done */
+	if (flags & SPI_XFER_END)
+		mmio_write_32(priv->mspi_hw + MSPI_WRITE_LOCK_REG, 0);
+
+	return ret;
+}