mtd: spi: Add Renesas RPC SPI-flash driver

Add driver for the RPC block in SPI-flash mode. This driver allows
access to a SPI NOR flash attached to the RPC block and does not
support RPC in Hyperflash mode. Note that this block is extremely
selective when communicating with the SPI NOR.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

3 files changed, 474 insertions, 0 deletions

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index d3e407ec11..ec92b84ed2 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -114,6 +114,14 @@ config PIC32_SPI
 	  to access the SPI NOR flash, MMC-over-SPI on platforms based on
 	  Microchip PIC32 family devices.
 
+config RENESAS_RPC_SPI
+	bool "Renesas RPC SPI driver"
+	depends on RCAR_GEN3
+	help
+	  Enable the Renesas RPC SPI driver, used to access SPI NOR flash
+	  on Renesas RCar Gen3 SoCs. This uses driver model and requires a
+	  device tree binding to operate.
+
 config ROCKCHIP_SPI
 	bool "Rockchip SPI driver"
 	help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 4b6000fd9a..176bfa05cf 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_MXS_SPI) += mxs_spi.o
 obj-$(CONFIG_ATCSPI200_SPI) += atcspi200_spi.o
 obj-$(CONFIG_OMAP3_SPI) += omap3_spi.o
 obj-$(CONFIG_PIC32_SPI) += pic32_spi.o
+obj-$(CONFIG_RENESAS_RPC_SPI) += renesas_rpc_spi.o
 obj-$(CONFIG_ROCKCHIP_SPI) += rk_spi.o
 obj-$(CONFIG_SANDBOX_SPI) += sandbox_spi.o
 obj-$(CONFIG_SH_SPI) += sh_spi.o
diff --git a/drivers/spi/renesas_rpc_spi.c b/drivers/spi/renesas_rpc_spi.c
new file mode 100644
index 0000000000..e54f24c5d8
--- /dev/null
+++ b/drivers/spi/renesas_rpc_spi.c
@@ -0,0 +1,465 @@
+/*
+ * Renesas RCar Gen3 RPC QSPI driver
+ *
+ * Copyright (C) 2018 Marek Vasut <marek.vasut@gmail.com>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <clk.h>
+#include <dm.h>
+#include <dm/of_access.h>
+#include <dt-structs.h>
+#include <errno.h>
+#include <linux/errno.h>
+#include <spi.h>
+#include <wait_bit.h>
+
+#define RPC_CMNCR		0x0000	/* R/W */
+#define RPC_CMNCR_MD		BIT(31)
+#define RPC_CMNCR_SFDE		BIT(24)
+#define RPC_CMNCR_MOIIO3(val)	(((val) & 0x3) << 22)
+#define RPC_CMNCR_MOIIO2(val)	(((val) & 0x3) << 20)
+#define RPC_CMNCR_MOIIO1(val)	(((val) & 0x3) << 18)
+#define RPC_CMNCR_MOIIO0(val)	(((val) & 0x3) << 16)
+#define RPC_CMNCR_MOIIO_HIZ	(RPC_CMNCR_MOIIO0(3) | RPC_CMNCR_MOIIO1(3) | \
+				 RPC_CMNCR_MOIIO2(3) | RPC_CMNCR_MOIIO3(3))
+#define RPC_CMNCR_IO3FV(val)	(((val) & 0x3) << 14)
+#define RPC_CMNCR_IO2FV(val)	(((val) & 0x3) << 12)
+#define RPC_CMNCR_IO0FV(val)	(((val) & 0x3) << 8)
+#define RPC_CMNCR_IOFV_HIZ	(RPC_CMNCR_IO0FV(3) | RPC_CMNCR_IO2FV(3) | \
+				 RPC_CMNCR_IO3FV(3))
+#define RPC_CMNCR_CPHAT		BIT(6)
+#define RPC_CMNCR_CPHAR		BIT(5)
+#define RPC_CMNCR_SSLP		BIT(4)
+#define RPC_CMNCR_CPOL		BIT(3)
+#define RPC_CMNCR_BSZ(val)	(((val) & 0x3) << 0)
+
+#define RPC_SSLDR		0x0004	/* R/W */
+#define RPC_SSLDR_SPNDL(d)	(((d) & 0x7) << 16)
+#define RPC_SSLDR_SLNDL(d)	(((d) & 0x7) << 8)
+#define RPC_SSLDR_SCKDL(d)	(((d) & 0x7) << 0)
+
+#define RPC_DRCR		0x000C	/* R/W */
+#define RPC_DRCR_SSLN		BIT(24)
+#define RPC_DRCR_RBURST(v)	(((v) & 0x1F) << 16)
+#define RPC_DRCR_RCF		BIT(9)
+#define RPC_DRCR_RBE		BIT(8)
+#define RPC_DRCR_SSLE		BIT(0)
+
+#define RPC_DRCMR		0x0010	/* R/W */
+#define RPC_DRCMR_CMD(c)	(((c) & 0xFF) << 16)
+#define RPC_DRCMR_OCMD(c)	(((c) & 0xFF) << 0)
+
+#define RPC_DREAR		0x0014	/* R/W */
+#define RPC_DREAR_EAV(v)	(((v) & 0xFF) << 16)
+#define RPC_DREAR_EAC(v)	(((v) & 0x7) << 0)
+
+#define RPC_DROPR		0x0018	/* R/W */
+#define RPC_DROPR_OPD3(o)	(((o) & 0xFF) << 24)
+#define RPC_DROPR_OPD2(o)	(((o) & 0xFF) << 16)
+#define RPC_DROPR_OPD1(o)	(((o) & 0xFF) << 8)
+#define RPC_DROPR_OPD0(o)	(((o) & 0xFF) << 0)
+
+#define RPC_DRENR		0x001C	/* R/W */
+#define RPC_DRENR_CDB(o)	(u32)((((o) & 0x3) << 30))
+#define RPC_DRENR_OCDB(o)	(((o) & 0x3) << 28)
+#define RPC_DRENR_ADB(o)	(((o) & 0x3) << 24)
+#define RPC_DRENR_OPDB(o)	(((o) & 0x3) << 20)
+#define RPC_DRENR_SPIDB(o)	(((o) & 0x3) << 16)
+#define RPC_DRENR_DME		BIT(15)
+#define RPC_DRENR_CDE		BIT(14)
+#define RPC_DRENR_OCDE		BIT(12)
+#define RPC_DRENR_ADE(v)	(((v) & 0xF) << 8)
+#define RPC_DRENR_OPDE(v)	(((v) & 0xF) << 4)
+
+#define RPC_SMCR		0x0020	/* R/W */
+#define RPC_SMCR_SSLKP		BIT(8)
+#define RPC_SMCR_SPIRE		BIT(2)
+#define RPC_SMCR_SPIWE		BIT(1)
+#define RPC_SMCR_SPIE		BIT(0)
+
+#define RPC_SMCMR		0x0024	/* R/W */
+#define RPC_SMCMR_CMD(c)	(((c) & 0xFF) << 16)
+#define RPC_SMCMR_OCMD(c)	(((c) & 0xFF) << 0)
+
+#define RPC_SMADR		0x0028	/* R/W */
+#define RPC_SMOPR		0x002C	/* R/W */
+#define RPC_SMOPR_OPD0(o)	(((o) & 0xFF) << 0)
+#define RPC_SMOPR_OPD1(o)	(((o) & 0xFF) << 8)
+#define RPC_SMOPR_OPD2(o)	(((o) & 0xFF) << 16)
+#define RPC_SMOPR_OPD3(o)	(((o) & 0xFF) << 24)
+
+#define RPC_SMENR		0x0030	/* R/W */
+#define RPC_SMENR_CDB(o)	(((o) & 0x3) << 30)
+#define RPC_SMENR_OCDB(o)	(((o) & 0x3) << 28)
+#define RPC_SMENR_ADB(o)	(((o) & 0x3) << 24)
+#define RPC_SMENR_OPDB(o)	(((o) & 0x3) << 20)
+#define RPC_SMENR_SPIDB(o)	(((o) & 0x3) << 16)
+#define RPC_SMENR_DME		BIT(15)
+#define RPC_SMENR_CDE		BIT(14)
+#define RPC_SMENR_OCDE		BIT(12)
+#define RPC_SMENR_ADE(v)	(((v) & 0xF) << 8)
+#define RPC_SMENR_OPDE(v)	(((v) & 0xF) << 4)
+#define RPC_SMENR_SPIDE(v)	(((v) & 0xF) << 0)
+
+#define RPC_SMRDR0		0x0038	/* R */
+#define RPC_SMRDR1		0x003C	/* R */
+#define RPC_SMWDR0		0x0040	/* R/W */
+#define RPC_SMWDR1		0x0044	/* R/W */
+#define RPC_CMNSR		0x0048	/* R */
+#define RPC_CMNSR_SSLF		BIT(1)
+#define	RPC_CMNSR_TEND		BIT(0)
+
+#define RPC_DRDMCR		0x0058	/* R/W */
+#define RPC_DRDMCR_DMCYC(v)	(((v) & 0xF) << 0)
+
+#define RPC_DRDRENR		0x005C	/* R/W */
+#define RPC_DRDRENR_HYPE	(0x5 << 12)
+#define RPC_DRDRENR_ADDRE	BIT(8)
+#define RPC_DRDRENR_OPDRE	BIT(4)
+#define RPC_DRDRENR_DRDRE	BIT(0)
+
+#define RPC_SMDMCR		0x0060	/* R/W */
+#define RPC_SMDMCR_DMCYC(v)	(((v) & 0xF) << 0)
+
+#define RPC_SMDRENR		0x0064	/* R/W */
+#define RPC_SMDRENR_HYPE	(0x5 << 12)
+#define RPC_SMDRENR_ADDRE	BIT(8)
+#define RPC_SMDRENR_OPDRE	BIT(4)
+#define RPC_SMDRENR_SPIDRE	BIT(0)
+
+#define RPC_PHYCNT		0x007C	/* R/W */
+#define RPC_PHYCNT_CAL		BIT(31)
+#define PRC_PHYCNT_OCTA_AA	BIT(22)
+#define PRC_PHYCNT_OCTA_SA	BIT(23)
+#define PRC_PHYCNT_EXDS		BIT(21)
+#define RPC_PHYCNT_OCT		BIT(20)
+#define RPC_PHYCNT_STRTIM(v)	(((v) & 0x7) << 15)
+#define RPC_PHYCNT_WBUF2	BIT(4)
+#define RPC_PHYCNT_WBUF		BIT(2)
+#define RPC_PHYCNT_MEM(v)	(((v) & 0x3) << 0)
+
+#define RPC_PHYINT		0x0088	/* R/W */
+#define RPC_PHYINT_RSTEN	BIT(18)
+#define RPC_PHYINT_WPEN		BIT(17)
+#define RPC_PHYINT_INTEN	BIT(16)
+#define RPC_PHYINT_RST		BIT(2)
+#define RPC_PHYINT_WP		BIT(1)
+#define RPC_PHYINT_INT		BIT(0)
+
+#define RPC_WBUF		0x8000	/* R/W size=4/8/16/32/64Bytes */
+#define RPC_WBUF_SIZE		0x100
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct rpc_spi_platdata {
+	fdt_addr_t	regs;
+	fdt_addr_t	extr;
+	s32		freq;	/* Default clock freq, -1 for none */
+};
+
+struct rpc_spi_priv {
+	fdt_addr_t	regs;
+	fdt_addr_t	extr;
+	struct clk	clk;
+
+	u8		cmdcopy[8];
+	u32		cmdlen;
+	bool		cmdstarted;
+};
+
+static int rpc_spi_wait_sslf(struct udevice *dev)
+{
+	struct rpc_spi_priv *priv = dev_get_priv(dev->parent);
+
+	return wait_for_bit_le32((void *)priv->regs + RPC_CMNSR, RPC_CMNSR_SSLF,
+				 false, 1000, false);
+}
+
+static int rpc_spi_wait_tend(struct udevice *dev)
+{
+	struct rpc_spi_priv *priv = dev_get_priv(dev->parent);
+
+	return wait_for_bit_le32((void *)priv->regs + RPC_CMNSR, RPC_CMNSR_TEND,
+				 true, 1000, false);
+}
+
+static void rpc_spi_flush_read_cache(struct udevice *dev)
+{
+	struct udevice *bus = dev->parent;
+	struct rpc_spi_priv *priv = dev_get_priv(bus);
+
+	/* Flush read cache */
+	writel(RPC_DRCR_SSLN | RPC_DRCR_RBURST(0x1f) |
+	       RPC_DRCR_RCF | RPC_DRCR_RBE | RPC_DRCR_SSLE,
+	       priv->regs + RPC_DRCR);
+	readl(priv->regs + RPC_DRCR);
+
+}
+
+static int rpc_spi_claim_bus(struct udevice *dev, bool manual)
+{
+	struct udevice *bus = dev->parent;
+	struct rpc_spi_priv *priv = dev_get_priv(bus);
+
+	/*
+	 * NOTE: The 0x260 are undocumented bits, but they must be set.
+	 * NOTE: On H3 ES1.x (not supported in mainline U-Boot), the
+	 *       RPC_PHYCNT_STRTIM shall be 0, while on newer parts, the
+	 *       RPC_PHYCNT_STRTIM shall be 6.
+	 */
+	writel(RPC_PHYCNT_CAL | RPC_PHYCNT_STRTIM(6) | 0x260,
+	       priv->regs + RPC_PHYCNT);
+	writel((manual ? RPC_CMNCR_MD : 0) | RPC_CMNCR_SFDE |
+		 RPC_CMNCR_MOIIO_HIZ | RPC_CMNCR_IOFV_HIZ | RPC_CMNCR_BSZ(0),
+		 priv->regs + RPC_CMNCR);
+
+	writel(RPC_SSLDR_SPNDL(7) | RPC_SSLDR_SLNDL(7) |
+	       RPC_SSLDR_SCKDL(7), priv->regs + RPC_SSLDR);
+
+	rpc_spi_flush_read_cache(dev);
+
+	return 0;
+}
+
+static int rpc_spi_release_bus(struct udevice *dev)
+{
+	struct udevice *bus = dev->parent;
+	struct rpc_spi_priv *priv = dev_get_priv(bus);
+
+	/* NOTE: The 0x260 are undocumented bits, but they must be set. */
+	writel(RPC_PHYCNT_STRTIM(6) | 0x260, priv->regs + RPC_PHYCNT);
+
+	rpc_spi_flush_read_cache(dev);
+
+	return 0;
+}
+
+static int rpc_spi_xfer(struct udevice *dev, unsigned int bitlen,
+			const void *dout, void *din, unsigned long flags)
+{
+	struct udevice *bus = dev->parent;
+	struct rpc_spi_priv *priv = dev_get_priv(bus);
+	u32 wlen = dout ? (bitlen / 8) : 0;
+	u32 rlen = din ? (bitlen / 8) : 0;
+	u32 wloop = DIV_ROUND_UP(wlen, 4);
+	u32 smenr, smcr, offset;
+	int ret = 0;
+
+	if (!priv->cmdstarted) {
+		if (!wlen || rlen)
+			BUG();
+
+		memcpy(priv->cmdcopy, dout, wlen);
+		priv->cmdlen = wlen;
+
+		/* Command transfer start */
+		priv->cmdstarted = true;
+		if (!(flags & SPI_XFER_END))
+			return 0;
+	}
+
+	offset = (priv->cmdcopy[1] << 16) | (priv->cmdcopy[2] << 8) |
+		 (priv->cmdcopy[3] << 0);
+
+	smenr = 0;
+
+	if (wlen || (!rlen && !wlen) || flags == SPI_XFER_ONCE) {
+		if (wlen && flags == SPI_XFER_END)
+			smenr = RPC_SMENR_SPIDE(0xf);
+
+		rpc_spi_claim_bus(dev, true);
+
+		writel(0, priv->regs + RPC_SMCR);
+
+		if (priv->cmdlen >= 1) {	/* Command(1) */
+			writel(RPC_SMCMR_CMD(priv->cmdcopy[0]),
+			       priv->regs + RPC_SMCMR);
+			smenr |= RPC_SMENR_CDE;
+		} else {
+			writel(0, priv->regs + RPC_SMCMR);
+		}
+
+		if (priv->cmdlen >= 4) {	/* Address(3) */
+			writel(offset, priv->regs + RPC_SMADR);
+			smenr |= RPC_SMENR_ADE(7);
+		} else {
+			writel(0, priv->regs + RPC_SMADR);
+		}
+
+		if (priv->cmdlen >= 5) {	/* Dummy(n) */
+			writel(8 * (priv->cmdlen - 4) - 1,
+			       priv->regs + RPC_SMDMCR);
+			smenr |= RPC_SMENR_DME;
+		} else {
+			writel(0, priv->regs + RPC_SMDMCR);
+		}
+
+		writel(0, priv->regs + RPC_SMOPR);
+
+		writel(0, priv->regs + RPC_SMDRENR);
+
+		if (wlen && flags == SPI_XFER_END) {
+			u32 *datout = (u32 *)dout;
+
+			while (wloop--) {
+				smcr = RPC_SMCR_SPIWE | RPC_SMCR_SPIE;
+				if (wloop >= 1)
+					smcr |= RPC_SMCR_SSLKP;
+				writel(smenr, priv->regs + RPC_SMENR);
+				writel(*datout, priv->regs + RPC_SMWDR0);
+				writel(smcr, priv->regs + RPC_SMCR);
+				ret = rpc_spi_wait_tend(dev);
+				if (ret)
+					goto err;
+				datout++;
+				smenr = RPC_SMENR_SPIDE(0xf);
+			}
+
+			ret = rpc_spi_wait_sslf(dev);
+
+		} else {
+			writel(smenr, priv->regs + RPC_SMENR);
+			writel(RPC_SMCR_SPIE, priv->regs + RPC_SMCR);
+			ret = rpc_spi_wait_tend(dev);
+		}
+	} else {	/* Read data only, using DRx ext access */
+		rpc_spi_claim_bus(dev, false);
+
+		if (priv->cmdlen >= 1) {	/* Command(1) */
+			writel(RPC_DRCMR_CMD(priv->cmdcopy[0]),
+			       priv->regs + RPC_DRCMR);
+			smenr |= RPC_DRENR_CDE;
+		} else {
+			writel(0, priv->regs + RPC_DRCMR);
+		}
+
+		if (priv->cmdlen >= 4)		/* Address(3) */
+			smenr |= RPC_DRENR_ADE(7);
+
+		if (priv->cmdlen >= 5) {	/* Dummy(n) */
+			writel(8 * (priv->cmdlen - 4) - 1,
+			       priv->regs + RPC_DRDMCR);
+			smenr |= RPC_DRENR_DME;
+		} else {
+			writel(0, priv->regs + RPC_DRDMCR);
+		}
+
+		writel(0, priv->regs + RPC_DROPR);
+
+		writel(smenr, priv->regs + RPC_DRENR);
+
+		if (rlen)
+			memcpy_fromio(din, (void *)(priv->extr + offset), rlen);
+		else
+			readl(priv->extr);	/* Dummy read */
+	}
+
+err:
+	priv->cmdstarted = false;
+
+	rpc_spi_release_bus(dev);
+
+	return ret;
+}
+
+static int rpc_spi_set_speed(struct udevice *bus, uint speed)
+{
+	/* This is a SPI NOR controller, do nothing. */
+	return 0;
+}
+
+static int rpc_spi_set_mode(struct udevice *bus, uint mode)
+{
+	/* This is a SPI NOR controller, do nothing. */
+	return 0;
+}
+
+static int rpc_spi_bind(struct udevice *parent)
+{
+	const void *fdt = gd->fdt_blob;
+	ofnode node;
+	int ret, off;
+
+	/*
+	 * Check if there are any SPI NOR child nodes, if so, bind as
+	 * this controller will be operated in SPI mode.
+	 */
+	dev_for_each_subnode(node, parent) {
+		off = ofnode_to_offset(node);
+
+		ret = fdt_node_check_compatible(fdt, off, "spi-flash");
+		if (!ret)
+			return 0;
+
+		ret = fdt_node_check_compatible(fdt, off, "jedec,spi-nor");
+		if (!ret)
+			return 0;
+	}
+
+	return -ENODEV;
+}
+
+static int rpc_spi_probe(struct udevice *dev)
+{
+	struct rpc_spi_platdata *plat = dev_get_platdata(dev);
+	struct rpc_spi_priv *priv = dev_get_priv(dev);
+
+	priv->regs = plat->regs;
+	priv->extr = plat->extr;
+
+	clk_enable(&priv->clk);
+
+	return 0;
+}
+
+static int rpc_spi_ofdata_to_platdata(struct udevice *bus)
+{
+	struct rpc_spi_platdata *plat = dev_get_platdata(bus);
+	struct rpc_spi_priv *priv = dev_get_priv(bus);
+	int ret;
+
+	plat->regs = dev_read_addr_index(bus, 0);
+	plat->extr = dev_read_addr_index(bus, 1);
+
+	ret = clk_get_by_index(bus, 0, &priv->clk);
+	if (ret < 0) {
+		printf("%s: Could not get clock for %s: %d\n",
+		       __func__, bus->name, ret);
+		return ret;
+	}
+
+	plat->freq = dev_read_u32_default(bus, "spi-max-freq", 50000000);
+
+	return 0;
+}
+
+static const struct dm_spi_ops rpc_spi_ops = {
+	.xfer		= rpc_spi_xfer,
+	.set_speed	= rpc_spi_set_speed,
+	.set_mode	= rpc_spi_set_mode,
+};
+
+static const struct udevice_id rpc_spi_ids[] = {
+	{ .compatible = "renesas,rpc-r8a7795" },
+	{ .compatible = "renesas,rpc-r8a7796" },
+	{ .compatible = "renesas,rpc-r8a77965" },
+	{ .compatible = "renesas,rpc-r8a77970" },
+	{ .compatible = "renesas,rpc-r8a77995" },
+	{ }
+};
+
+U_BOOT_DRIVER(rpc_spi) = {
+	.name		= "rpc_spi",
+	.id		= UCLASS_SPI,
+	.of_match	= rpc_spi_ids,
+	.ops		= &rpc_spi_ops,
+	.ofdata_to_platdata = rpc_spi_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct rpc_spi_platdata),
+	.priv_auto_alloc_size = sizeof(struct rpc_spi_priv),
+	.bind		= rpc_spi_bind,
+	.probe		= rpc_spi_probe,
+};