spi: synquacer: Add HSSPI SPI controller driver for SynQuacer

This is a driver for the HSSPI SPI controller on SynQuacer SoC.
The HSSPI has command sequence mode (memory mapped) and
direct mode (FIFO access). The driver will operate it under
the direct mode. And before booting OS, it switch back to the
command sequence mode since that is compatible with default
EDK2 behavior.

Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>

3 files changed, 500 insertions, 0 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index e317d8a2c6..5c2a60a214 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -488,4 +488,12 @@ config MXC_SPI
 	  Enable the MXC SPI controller driver. This driver can be used
 	  on various i.MX SoCs such as i.MX31/35/51/6/7.
 
+config SYNQUACER_SPI
+	bool "Socionext SynQuacer HS-SPI driver"
+	depends on ARCH_SYNQUACER
+	help
+	  Enable the Socionext HS-SPI driver for SynQuacer. This driver can
+	  be used to access the SPI interface and SPI NOR flash on platforms
+	  embedding this HS-SPI IP core.
+
 endif # menu "SPI Support"
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 3dc83089b8..f70851e4bc 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_EXYNOS_SPI) += exynos_spi.o
 obj-$(CONFIG_FSL_DSPI) += fsl_dspi.o
 obj-$(CONFIG_FSL_ESPI) += fsl_espi.o
 obj-$(CONFIG_FSL_QSPI) += fsl_qspi.o
+obj-$(CONFIG_SYNQUACER_SPI) += spi-synquacer.o
 obj-$(CONFIG_ICH_SPI) +=  ich.o
 obj-$(CONFIG_KIRKWOOD_SPI) += kirkwood_spi.o
 obj-$(CONFIG_MESON_SPIFC) += meson_spifc.o
diff --git a/drivers/spi/spi-synquacer.c b/drivers/spi/spi-synquacer.c
new file mode 100644
index 0000000000..ce558c4bc0
--- /dev/null
+++ b/drivers/spi/spi-synquacer.c
@@ -0,0 +1,491 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * spi-synquacer.c - Socionext Synquacer SPI driver
+ * Copyright 2021 Linaro Ltd.
+ * Copyright 2021 Socionext, Inc.
+ */
+
+#include <clk.h>
+#include <common.h>
+#include <dm.h>
+#include <log.h>
+#include <time.h>
+#include <dm/device_compat.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <spi.h>
+#include <wait_bit.h>
+
+#define MCTRL	0x0
+#define MEN	0
+#define CSEN	1
+#define IPCLK	3
+#define MES	4
+#define SYNCON	5
+
+#define PCC0		0x4
+#define PCC(n)		(PCC0 + (n) * 4)
+#define RTM		3
+#define ACES		2
+#define SAFESYNC	16
+#define CPHA		0
+#define CPOL		1
+#define SSPOL		4
+#define SDIR		7
+#define SS2CD		5
+#define SENDIAN		8
+#define CDRS_SHIFT	9
+#define CDRS_MASK	0x7f
+
+#define TXF		0x14
+#define TXE		0x18
+#define TXC		0x1c
+#define RXF		0x20
+#define RXE		0x24
+#define RXC		0x28
+#define TFLETE		4
+#define RFMTE		5
+
+#define FAULTF		0x2c
+#define FAULTC		0x30
+
+#define DMCFG		0x34
+#define SSDC		1
+#define MSTARTEN	2
+
+#define DMSTART		0x38
+#define TRIGGER		0
+#define DMSTOP		8
+#define CS_MASK		3
+#define CS_SHIFT	16
+#define DATA_TXRX	0
+#define DATA_RX		1
+#define DATA_TX		2
+#define DATA_MASK	3
+#define DATA_SHIFT	26
+#define BUS_WIDTH	24
+
+#define DMBCC		0x3c
+#define DMSTATUS	0x40
+#define RX_DATA_MASK	0x1f
+#define RX_DATA_SHIFT	8
+#define TX_DATA_MASK	0x1f
+#define TX_DATA_SHIFT	16
+
+#define TXBITCNT	0x44
+
+#define FIFOCFG		0x4c
+#define BPW_MASK	0x3
+#define BPW_SHIFT	8
+#define RX_FLUSH	11
+#define TX_FLUSH	12
+#define RX_TRSHLD_MASK		0xf
+#define RX_TRSHLD_SHIFT		0
+#define TX_TRSHLD_MASK		0xf
+#define TX_TRSHLD_SHIFT		4
+
+#define TXFIFO		0x50
+#define RXFIFO		0x90
+#define MID		0xfc
+
+#define FIFO_DEPTH	16
+#define TX_TRSHLD	4
+#define RX_TRSHLD	(FIFO_DEPTH - TX_TRSHLD)
+
+#define TXBIT	1
+#define RXBIT	2
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct synquacer_spi_plat {
+	void __iomem *base;
+	bool aces, rtm;
+};
+
+struct synquacer_spi_priv {
+	void __iomem *base;
+	bool aces, rtm;
+	int speed, cs, mode, rwflag;
+	void *rx_buf;
+	const void *tx_buf;
+	unsigned int tx_words, rx_words;
+};
+
+static void read_fifo(struct synquacer_spi_priv *priv)
+{
+	u32 len = readl(priv->base + DMSTATUS);
+	u8 *buf = priv->rx_buf;
+	int i;
+
+	len = (len >> RX_DATA_SHIFT) & RX_DATA_MASK;
+	len = min_t(unsigned int, len, priv->rx_words);
+
+	for (i = 0; i < len; i++)
+		*buf++ = readb(priv->base + RXFIFO);
+
+	priv->rx_buf = buf;
+	priv->rx_words -= len;
+}
+
+static void write_fifo(struct synquacer_spi_priv *priv)
+{
+	u32 len = readl(priv->base + DMSTATUS);
+	const u8 *buf = priv->tx_buf;
+	int i;
+
+	len = (len >> TX_DATA_SHIFT) & TX_DATA_MASK;
+	len = min_t(unsigned int, FIFO_DEPTH - len, priv->tx_words);
+
+	for (i = 0; i < len; i++)
+		writeb(*buf++, priv->base + TXFIFO);
+
+	priv->tx_buf = buf;
+	priv->tx_words -= len;
+}
+
+static void synquacer_cs_set(struct synquacer_spi_priv *priv, bool active)
+{
+	u32 val;
+
+	val = readl(priv->base + DMSTART);
+	val &= ~(CS_MASK << CS_SHIFT);
+	val |= priv->cs << CS_SHIFT;
+
+	if (active) {
+		writel(val, priv->base + DMSTART);
+
+		val = readl(priv->base + DMSTART);
+		val &= ~BIT(DMSTOP);
+		writel(val, priv->base + DMSTART);
+	} else {
+		val |= BIT(DMSTOP);
+		writel(val, priv->base + DMSTART);
+
+		if (priv->rx_buf) {
+			u32 buf[16];
+
+			priv->rx_buf = buf;
+			priv->rx_words = 16;
+			read_fifo(priv);
+		}
+	}
+}
+
+static void synquacer_spi_config(struct udevice *dev, void *rx, const void *tx)
+{
+	struct udevice *bus = dev->parent;
+	struct synquacer_spi_priv *priv = dev_get_priv(bus);
+	struct dm_spi_slave_plat *slave_plat = dev_get_parent_plat(dev);
+	u32 val, div, bus_width;
+	int rwflag;
+
+	rwflag = (rx ? 1 : 0) | (tx ? 2 : 0);
+
+	/* if nothing to do */
+	if (slave_plat->mode == priv->mode &&
+	    rwflag == priv->rwflag &&
+	    slave_plat->cs == priv->cs &&
+	    slave_plat->max_hz == priv->speed)
+		return;
+
+	priv->rwflag = rwflag;
+	priv->cs = slave_plat->cs;
+	priv->mode = slave_plat->mode;
+	priv->speed = slave_plat->max_hz;
+
+	if (priv->mode & SPI_TX_BYTE)
+		bus_width = 1;
+	else if (priv->mode & SPI_TX_DUAL)
+		bus_width = 2;
+	else if (priv->mode & SPI_TX_QUAD)
+		bus_width = 4;
+	else if (priv->mode & SPI_TX_OCTAL)
+		bus_width = 8;
+
+	div = DIV_ROUND_UP(125000000, priv->speed);
+
+	val = readl(priv->base + PCC(priv->cs));
+	val &= ~BIT(RTM);
+	val &= ~BIT(ACES);
+	val &= ~BIT(SAFESYNC);
+	if ((priv->mode & (SPI_TX_DUAL | SPI_RX_DUAL)) && div < 3)
+		val |= BIT(SAFESYNC);
+	if ((priv->mode & (SPI_TX_QUAD | SPI_RX_QUAD)) && div < 6)
+		val |= BIT(SAFESYNC);
+
+	if (priv->mode & SPI_CPHA)
+		val |= BIT(CPHA);
+	else
+		val &= ~BIT(CPHA);
+
+	if (priv->mode & SPI_CPOL)
+		val |= BIT(CPOL);
+	else
+		val &= ~BIT(CPOL);
+
+	if (priv->mode & SPI_CS_HIGH)
+		val |= BIT(SSPOL);
+	else
+		val &= ~BIT(SSPOL);
+
+	if (priv->mode & SPI_LSB_FIRST)
+		val |= BIT(SDIR);
+	else
+		val &= ~BIT(SDIR);
+
+	if (priv->aces)
+		val |= BIT(ACES);
+
+	if (priv->rtm)
+		val |= BIT(RTM);
+
+	val |= (3 << SS2CD);
+	val |= BIT(SENDIAN);
+
+	val &= ~(CDRS_MASK << CDRS_SHIFT);
+	val |= ((div >> 1) << CDRS_SHIFT);
+
+	writel(val, priv->base + PCC(priv->cs));
+
+	val = readl(priv->base + FIFOCFG);
+	val &= ~(BPW_MASK << BPW_SHIFT);
+	val |= (0 << BPW_SHIFT);
+	writel(val, priv->base + FIFOCFG);
+
+	val = readl(priv->base + DMSTART);
+	val &= ~(DATA_MASK << DATA_SHIFT);
+
+	if (tx && rx)
+		val |= (DATA_TXRX << DATA_SHIFT);
+	else if (rx)
+		val |= (DATA_RX << DATA_SHIFT);
+	else
+		val |= (DATA_TX << DATA_SHIFT);
+
+	val &= ~(3 << BUS_WIDTH);
+	val |= ((bus_width >> 1) << BUS_WIDTH);
+	writel(val, priv->base + DMSTART);
+}
+
+static int synquacer_spi_xfer(struct udevice *dev, unsigned int bitlen,
+			      const void *tx_buf, void *rx_buf,
+			      unsigned long flags)
+{
+	struct udevice *bus = dev->parent;
+	struct synquacer_spi_priv *priv = dev_get_priv(bus);
+	u32 val, words, busy;
+
+	val = readl(priv->base + FIFOCFG);
+	val |= (1 << RX_FLUSH);
+	val |= (1 << TX_FLUSH);
+	writel(val, priv->base + FIFOCFG);
+
+	synquacer_spi_config(dev, rx_buf, tx_buf);
+
+	priv->tx_buf = tx_buf;
+	priv->rx_buf = rx_buf;
+
+	words = bitlen / 8;
+
+	if (tx_buf) {
+		busy |= BIT(TXBIT);
+		priv->tx_words = words;
+	} else {
+		busy &= ~BIT(TXBIT);
+		priv->tx_words = 0;
+	}
+
+	if (rx_buf) {
+		busy |= BIT(RXBIT);
+		priv->rx_words = words;
+	} else {
+		busy &= ~BIT(RXBIT);
+		priv->rx_words = 0;
+	}
+
+	if (flags & SPI_XFER_BEGIN)
+		synquacer_cs_set(priv, true);
+
+	if (tx_buf)
+		write_fifo(priv);
+
+	if (rx_buf) {
+		val = readl(priv->base + FIFOCFG);
+		val &= ~(RX_TRSHLD_MASK << RX_TRSHLD_SHIFT);
+		val |= ((priv->rx_words > FIFO_DEPTH ?
+			RX_TRSHLD : priv->rx_words) << RX_TRSHLD_SHIFT);
+		writel(val, priv->base + FIFOCFG);
+	}
+
+	writel(~0, priv->base + TXC);
+	writel(~0, priv->base + RXC);
+
+	/* Trigger */
+	val = readl(priv->base + DMSTART);
+	val |= BIT(TRIGGER);
+	writel(val, priv->base + DMSTART);
+
+	while (busy & (BIT(RXBIT) | BIT(TXBIT))) {
+		if (priv->rx_words)
+			read_fifo(priv);
+		else
+			busy &= ~BIT(RXBIT);
+
+		if (priv->tx_words) {
+			write_fifo(priv);
+		} else {
+			u32 len;
+
+			do { /* wait for shifter to empty out */
+				cpu_relax();
+				len = readl(priv->base + DMSTATUS);
+				len = (len >> TX_DATA_SHIFT) & TX_DATA_MASK;
+			} while (tx_buf && len);
+			busy &= ~BIT(TXBIT);
+		}
+	}
+
+	if (flags & SPI_XFER_END)
+		synquacer_cs_set(priv, false);
+
+	return 0;
+}
+
+static int synquacer_spi_set_speed(struct udevice *bus, uint speed)
+{
+	return 0;
+}
+
+static int synquacer_spi_set_mode(struct udevice *bus, uint mode)
+{
+	return 0;
+}
+
+static int synquacer_spi_claim_bus(struct udevice *dev)
+{
+	return 0;
+}
+
+static int synquacer_spi_release_bus(struct udevice *dev)
+{
+	return 0;
+}
+
+static void synquacer_spi_disable_module(struct synquacer_spi_priv *priv)
+{
+	writel(0, priv->base + MCTRL);
+	while (readl(priv->base + MCTRL) & BIT(MES))
+		cpu_relax();
+}
+
+static void synquacer_spi_init(struct synquacer_spi_priv *priv)
+{
+	u32 val;
+
+	synquacer_spi_disable_module(priv);
+
+	writel(0, priv->base + TXE);
+	writel(0, priv->base + RXE);
+	val = readl(priv->base + TXF);
+	writel(val, priv->base + TXC);
+	val = readl(priv->base + RXF);
+	writel(val, priv->base + RXC);
+	val = readl(priv->base + FAULTF);
+	writel(val, priv->base + FAULTC);
+
+	val = readl(priv->base + DMCFG);
+	val &= ~BIT(SSDC);
+	val &= ~BIT(MSTARTEN);
+	writel(val, priv->base + DMCFG);
+
+	/* Enable module with direct mode */
+	val = readl(priv->base + MCTRL);
+	val &= ~BIT(IPCLK);
+	val &= ~BIT(CSEN);
+	val |= BIT(MEN);
+	val |= BIT(SYNCON);
+	writel(val, priv->base + MCTRL);
+}
+
+static void synquacer_spi_exit(struct synquacer_spi_priv *priv)
+{
+	u32 val;
+
+	synquacer_spi_disable_module(priv);
+
+	/* Enable module with command sequence mode */
+	val = readl(priv->base + MCTRL);
+	val &= ~BIT(IPCLK);
+	val |= BIT(CSEN);
+	val |= BIT(MEN);
+	val |= BIT(SYNCON);
+	writel(val, priv->base + MCTRL);
+
+	while (!(readl(priv->base + MCTRL) & BIT(MES)))
+		cpu_relax();
+}
+
+static int synquacer_spi_probe(struct udevice *bus)
+{
+	struct synquacer_spi_plat *plat = dev_get_plat(bus);
+	struct synquacer_spi_priv *priv = dev_get_priv(bus);
+
+	priv->base = plat->base;
+	priv->aces = plat->aces;
+	priv->rtm = plat->rtm;
+
+	synquacer_spi_init(priv);
+	return 0;
+}
+
+static int synquacer_spi_remove(struct udevice *bus)
+{
+	struct synquacer_spi_priv *priv = dev_get_priv(bus);
+
+	synquacer_spi_exit(priv);
+	return 0;
+}
+
+static int synquacer_spi_of_to_plat(struct udevice *bus)
+{
+	struct synquacer_spi_plat *plat = dev_get_plat(bus);
+	struct clk clk;
+
+	plat->base = dev_read_addr_ptr(bus);
+
+	plat->aces = dev_read_bool(bus, "socionext,set-aces");
+	plat->rtm = dev_read_bool(bus, "socionext,use-rtm");
+
+	clk_get_by_name(bus, "iHCLK", &clk);
+	clk_enable(&clk);
+
+	return 0;
+}
+
+static const struct dm_spi_ops synquacer_spi_ops = {
+	.claim_bus	= synquacer_spi_claim_bus,
+	.release_bus	= synquacer_spi_release_bus,
+	.xfer		= synquacer_spi_xfer,
+	.set_speed	= synquacer_spi_set_speed,
+	.set_mode	= synquacer_spi_set_mode,
+};
+
+static const struct udevice_id synquacer_spi_ids[] = {
+	{ .compatible = "socionext,synquacer-spi" },
+	{ /* Sentinel */ }
+};
+
+U_BOOT_DRIVER(synquacer_spi) = {
+	.name		= "synquacer_spi",
+	.id		= UCLASS_SPI,
+	.of_match	= synquacer_spi_ids,
+	.ops		= &synquacer_spi_ops,
+	.of_to_plat	= synquacer_spi_of_to_plat,
+	.plat_auto	= sizeof(struct synquacer_spi_plat),
+	.priv_auto	= sizeof(struct synquacer_spi_priv),
+	.probe		= synquacer_spi_probe,
+	.flags		= DM_FLAG_OS_PREPARE,
+	.remove		= synquacer_spi_remove,
+};