[PATCH v4 1/5] spi: rockchip_sfc: add support for Rockchip SFC

Chris Morgan macroalpha82 at gmail.com
Tue Jun 15 21:10:42 CEST 2021


From: Chris Morgan <macromorgan at hotmail.com>

This patch adds support for the Rockchip serial flash controller
found on the PX30 SoC. It should work for versions 3-5 of the SFC
IP, however I am only able to test it on v3.

This is adapted from the WIP SPI-MEM driver for the SFC on mainline
Linux. Note that the main difference between this and earlier versions
of the driver is that this one does not support DMA. In testing
the performance difference (performing a dual mode read on a 128Mb
chip) is negligible. DMA, if used, must also be disabled in SPL
mode when using A-TF anyway.

Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
---
 drivers/spi/Kconfig        |   8 +
 drivers/spi/Makefile       |   1 +
 drivers/spi/rockchip_sfc.c | 513 +++++++++++++++++++++++++++++++++++++
 3 files changed, 522 insertions(+)
 create mode 100644 drivers/spi/rockchip_sfc.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 1494c91763..bef36f2931 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -312,6 +312,14 @@ config RENESAS_RPC_SPI
 	  on Renesas RCar Gen3 SoCs. This uses driver model and requires a
 	  device tree binding to operate.
 
+config ROCKCHIP_SFC
+	bool "Rockchip SFC Driver"
+	help
+	  Enable the Rockchip SFC Driver for SPI NOR flash. This device is
+	  a limited purpose SPI controller for driving NOR flash on certain
+	  Rockchip 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 cfe4fae1d4..f02e84b5f1 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_PIC32_SPI) += pic32_spi.o
 obj-$(CONFIG_PL022_SPI) += pl022_spi.o
 obj-$(CONFIG_SPI_QUP) += spi-qup.o
 obj-$(CONFIG_RENESAS_RPC_SPI) += renesas_rpc_spi.o
+obj-$(CONFIG_ROCKCHIP_SFC) += rockchip_sfc.o
 obj-$(CONFIG_ROCKCHIP_SPI) += rk_spi.o
 obj-$(CONFIG_SANDBOX_SPI) += sandbox_spi.o
 obj-$(CONFIG_SPI_SIFIVE) += spi-sifive.o
diff --git a/drivers/spi/rockchip_sfc.c b/drivers/spi/rockchip_sfc.c
new file mode 100644
index 0000000000..2114842b0f
--- /dev/null
+++ b/drivers/spi/rockchip_sfc.c
@@ -0,0 +1,513 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Rockchip Serial Flash Controller Driver
+ *
+ * Copyright (c) 2017-2021, Rockchip Inc.
+ * Author: Shawn Lin <shawn.lin at rock-chips.com>
+ *	   Chris Morgan <macromorgan at hotmail.com>
+ *	   Jon Lin <Jon.lin at rock-chips.com>
+ */
+
+#include <asm/io.h>
+#include <clk.h>
+#include <dm.h>
+#include <linux/bitops.h>
+#include <linux/delay.h>
+#include <spi.h>
+#include <spi-mem.h>
+
+/* System control */
+#define SFC_CTRL			0x0
+#define  SFC_CTRL_PHASE_SEL_NEGETIVE	BIT(1)
+#define  SFC_CTRL_CMD_BITS_SHIFT	8
+#define  SFC_CTRL_ADDR_BITS_SHIFT	10
+#define  SFC_CTRL_DATA_BITS_SHIFT	12
+
+/* Interrupt mask */
+#define SFC_IMR				0x4
+#define  SFC_IMR_RX_FULL		BIT(0)
+#define  SFC_IMR_RX_UFLOW		BIT(1)
+#define  SFC_IMR_TX_OFLOW		BIT(2)
+#define  SFC_IMR_TX_EMPTY		BIT(3)
+#define  SFC_IMR_TRAN_FINISH		BIT(4)
+#define  SFC_IMR_BUS_ERR		BIT(5)
+#define  SFC_IMR_NSPI_ERR		BIT(6)
+#define  SFC_IMR_DMA			BIT(7)
+
+/* Interrupt clear */
+#define SFC_ICLR			0x8
+#define  SFC_ICLR_RX_FULL		BIT(0)
+#define  SFC_ICLR_RX_UFLOW		BIT(1)
+#define  SFC_ICLR_TX_OFLOW		BIT(2)
+#define  SFC_ICLR_TX_EMPTY		BIT(3)
+#define  SFC_ICLR_TRAN_FINISH		BIT(4)
+#define  SFC_ICLR_BUS_ERR		BIT(5)
+#define  SFC_ICLR_NSPI_ERR		BIT(6)
+#define  SFC_ICLR_DMA			BIT(7)
+
+/* FIFO threshold level */
+#define SFC_FTLR			0xc
+#define  SFC_FTLR_TX_SHIFT		0
+#define  SFC_FTLR_TX_MASK		0x1f
+#define  SFC_FTLR_RX_SHIFT		8
+#define  SFC_FTLR_RX_MASK		0x1f
+
+/* Reset FSM and FIFO */
+#define SFC_RCVR			0x10
+#define  SFC_RCVR_RESET			BIT(0)
+
+/* Enhanced mode */
+#define SFC_AX				0x14
+
+/* Address Bit number */
+#define SFC_ABIT			0x18
+
+/* Interrupt status */
+#define SFC_ISR				0x1c
+#define  SFC_ISR_RX_FULL_SHIFT		BIT(0)
+#define  SFC_ISR_RX_UFLOW_SHIFT		BIT(1)
+#define  SFC_ISR_TX_OFLOW_SHIFT		BIT(2)
+#define  SFC_ISR_TX_EMPTY_SHIFT		BIT(3)
+#define  SFC_ISR_TX_FINISH_SHIFT	BIT(4)
+#define  SFC_ISR_BUS_ERR_SHIFT		BIT(5)
+#define  SFC_ISR_NSPI_ERR_SHIFT		BIT(6)
+#define  SFC_ISR_DMA_SHIFT		BIT(7)
+
+/* FIFO status */
+#define SFC_FSR				0x20
+#define  SFC_FSR_TX_IS_FULL		BIT(0)
+#define  SFC_FSR_TX_IS_EMPTY		BIT(1)
+#define  SFC_FSR_RX_IS_EMPTY		BIT(2)
+#define  SFC_FSR_RX_IS_FULL		BIT(3)
+#define  SFC_FSR_TXLV_MASK		GENMASK(12, 8)
+#define  SFC_FSR_TXLV_SHIFT		8
+#define  SFC_FSR_RXLV_MASK		GENMASK(20, 16)
+#define  SFC_FSR_RXLV_SHIFT		16
+
+/* FSM status */
+#define SFC_SR				0x24
+#define  SFC_SR_IS_IDLE			0x0
+#define  SFC_SR_IS_BUSY			0x1
+
+/* Raw interrupt status */
+#define SFC_RISR			0x28
+#define  SFC_RISR_RX_FULL		BIT(0)
+#define  SFC_RISR_RX_UNDERFLOW		BIT(1)
+#define  SFC_RISR_TX_OVERFLOW		BIT(2)
+#define  SFC_RISR_TX_EMPTY		BIT(3)
+#define  SFC_RISR_TRAN_FINISH		BIT(4)
+#define  SFC_RISR_BUS_ERR		BIT(5)
+#define  SFC_RISR_NSPI_ERR		BIT(6)
+#define  SFC_RISR_DMA			BIT(7)
+
+/* Version */
+#define SFC_VER				0x2C
+#define  SFC_VER_3			0x3
+#define  SFC_VER_4			0x4
+#define  SFC_VER_5			0x5
+
+/* Master trigger */
+#define SFC_DMA_TRIGGER			0x80
+
+/* Src or Dst addr for master */
+#define SFC_DMA_ADDR			0x84
+
+/* Length Control Register Extension 32GB */
+#define SFC_LEN_CTRL			0x88
+#define SFC_LEN_CTRL_TRB_SEL		1
+#define SFC_LEN_EXT			0x8C
+
+/* Command */
+#define SFC_CMD				0x100
+#define  SFC_CMD_IDX_SHIFT		0
+#define  SFC_CMD_DUMMY_SHIFT		8
+#define  SFC_CMD_DIR_SHIFT		12
+#define  SFC_CMD_DIR_RD			0
+#define  SFC_CMD_DIR_WR			1
+#define  SFC_CMD_ADDR_SHIFT		14
+#define  SFC_CMD_ADDR_0BITS		0
+#define  SFC_CMD_ADDR_24BITS		1
+#define  SFC_CMD_ADDR_32BITS		2
+#define  SFC_CMD_ADDR_XBITS		3
+#define  SFC_CMD_TRAN_BYTES_SHIFT	16
+#define  SFC_CMD_CS_SHIFT		30
+
+/* Address */
+#define SFC_ADDR			0x104
+
+/* Data */
+#define SFC_DATA			0x108
+
+/* The controller and documentation reports that it supports up to 4 CS
+ * devices (0-3), however I have only been able to test a single CS (CS 0)
+ * due to the configuration of my device.
+ */
+#define SFC_MAX_CHIPSELECT_NUM		4
+
+/* The SFC can transfer max 16KB - 1 at one time
+ * we set it to 15.5KB here for alignment.
+ */
+#define SFC_MAX_IOSIZE_VER3		(512 * 31)
+
+#define SFC_MAX_IOSIZE_VER4		(0xFFFFFFFF)
+
+/* DMA is only enabled for large data transmission */
+#define SFC_DMA_TRANS_THRETHOLD		(0x40)
+
+/* Maximum clock values from datasheet suggest keeping clock value under
+ * 150MHz. No minimum or average value is suggested, but the U-boot BSP driver
+ * has a minimum of 10MHz and a default of 80MHz which seems reasonable.
+ */
+#define SFC_MIN_SPEED_HZ		(10 * 1000 * 1000)
+#define SFC_DEFAULT_SPEED_HZ		(80 * 1000 * 1000)
+#define SFC_MAX_SPEED_HZ		(150 * 1000 * 1000)
+
+struct rockchip_sfc {
+	void __iomem *regbase;
+	struct clk *hclk;
+	struct clk *clk;
+	u32 frequency;
+	u32 max_iosize;
+	u16 sfc_ver;
+};
+
+static u16 rockchip_sfc_get_version(struct rockchip_sfc *sfc)
+{
+	return  (u16)(readl(sfc->regbase + SFC_VER) & 0xffff);
+}
+
+static u32 rockchip_sfc_get_max_iosize(struct rockchip_sfc *sfc)
+{
+	if (rockchip_sfc_get_version(sfc) >= SFC_VER_4)
+		return SFC_MAX_IOSIZE_VER4;
+	else
+		return SFC_MAX_IOSIZE_VER3;
+}
+
+static int rockchip_sfc_init(struct rockchip_sfc *sfc)
+{
+	writel(0, sfc->regbase + SFC_CTRL);
+	if (rockchip_sfc_get_version(sfc) >= SFC_VER_4)
+		writel(SFC_LEN_CTRL_TRB_SEL, sfc->regbase + SFC_LEN_CTRL);
+
+	return 0;
+}
+
+static int rockchip_sfc_ofdata_to_platdata(struct udevice *bus)
+{
+	struct rockchip_sfc *sfc = dev_get_plat(bus);
+	int ret;
+
+	sfc->regbase = dev_read_addr_ptr(bus);
+
+	ret = clk_get_by_name(bus, "hclk_sfc", sfc->hclk);
+	if (ret < 0) {
+		printf("Could not get ahb clock for %s: %d\n", bus->name, ret);
+		return ret;
+	}
+
+	ret = clk_get_by_name(bus, "clk_sfc", sfc->clk);
+	if (ret < 0) {
+		printf("Could not get sfc clock for %s: %d\n", bus->name, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rockchip_sfc_probe(struct udevice *bus)
+{
+	struct rockchip_sfc *sfc = dev_get_plat(bus);
+	int ret;
+
+	ret = clk_prepare_enable(sfc->hclk);
+	if (ret) {
+		printf("Could not get ahb clock for %s: %d\n", bus->name, ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(sfc->clk);
+	if (ret) {
+		printf("Could not get sfc clock for %s: %d\n", bus->name, ret);
+		goto err_clk;
+	}
+
+	ret = clk_set_rate(sfc->clk, SFC_DEFAULT_SPEED_HZ);
+	if (ret) {
+		printf("Could not set sfc clock for %s: %d\n", bus->name, ret);
+		goto err_init;
+	}
+
+	ret = rockchip_sfc_init(sfc);
+	if (ret)
+		goto err_init;
+
+	sfc->max_iosize = rockchip_sfc_get_max_iosize(sfc);
+	sfc->sfc_ver = rockchip_sfc_get_version(sfc);
+
+	return 0;
+
+err_init:
+	clk_disable_unprepare(sfc->clk);
+err_clk:
+	clk_disable_unprepare(sfc->hclk);
+	return ret;
+}
+
+static void rockchip_sfc_adjust_op_work(struct spi_mem_op *op)
+{
+	if (unlikely(op->dummy.nbytes && !op->addr.nbytes)) {
+		/*
+		 * SFC not support output DUMMY cycles right after CMD cycles, so
+		 * treat it as ADDR cycles.
+		 */
+		op->addr.nbytes = op->dummy.nbytes;
+		op->addr.buswidth = op->dummy.buswidth;
+		op->addr.val = 0xFFFFFFFFF;
+
+		op->dummy.nbytes = 0;
+	}
+}
+
+static inline int rockchip_sfc_get_fifo_level(struct rockchip_sfc *sfc, int wr)
+{
+	u32 fsr = readl_relaxed(sfc->regbase + SFC_FSR);
+	int level;
+
+	if (wr)
+		level = (fsr & SFC_FSR_TXLV_MASK) >> SFC_FSR_TXLV_SHIFT;
+	else
+		level = (fsr & SFC_FSR_RXLV_MASK) >> SFC_FSR_RXLV_SHIFT;
+
+	return level;
+}
+
+static int rockchip_sfc_wait_fifo_ready(struct rockchip_sfc *sfc, int wr, u32 timeout)
+{
+	unsigned long tbase = get_timer(0);
+	int level;
+
+	while (!(level = rockchip_sfc_get_fifo_level(sfc, wr))) {
+		if (get_timer(tbase) > timeout)
+			return -ETIMEDOUT;
+		udelay(1);
+	}
+
+	return level;
+}
+
+static int rockchip_sfc_xfer_setup(struct rockchip_sfc *sfc,
+				   struct spi_slave *mem,
+				   const struct spi_mem_op *op,
+				   u32 len)
+{
+	struct dm_spi_slave_plat *plat = dev_get_parent_plat(mem->dev);
+	u32 ctrl = 0, cmd = 0;
+
+	/* set CMD */
+	cmd = op->cmd.opcode;
+	ctrl |= ((op->cmd.buswidth >> 1) << SFC_CTRL_CMD_BITS_SHIFT);
+
+	/* set ADDR */
+	if (op->addr.nbytes) {
+		if (op->addr.nbytes == 4) {
+			cmd |= SFC_CMD_ADDR_32BITS << SFC_CMD_ADDR_SHIFT;
+		} else if (op->addr.nbytes == 3) {
+			cmd |= SFC_CMD_ADDR_24BITS << SFC_CMD_ADDR_SHIFT;
+		} else {
+			cmd |= SFC_CMD_ADDR_XBITS << SFC_CMD_ADDR_SHIFT;
+			writel_relaxed(op->addr.nbytes * 8 - 1, sfc->regbase + SFC_ABIT);
+		}
+
+		ctrl |= ((op->addr.buswidth >> 1) << SFC_CTRL_ADDR_BITS_SHIFT);
+	}
+
+	/* set DUMMY */
+	if (op->dummy.nbytes) {
+		if (op->dummy.buswidth == 4)
+			cmd |= op->dummy.nbytes * 2 << SFC_CMD_DUMMY_SHIFT;
+		else if (op->dummy.buswidth == 2)
+			cmd |= op->dummy.nbytes * 4 << SFC_CMD_DUMMY_SHIFT;
+		else
+			cmd |= op->dummy.nbytes * 8 << SFC_CMD_DUMMY_SHIFT;
+	}
+
+	/* set DATA */
+	if (sfc->sfc_ver >= SFC_VER_4) /* Clear it if no data to transfer */
+		writel(len, sfc->regbase + SFC_LEN_EXT);
+	else
+		cmd |= len << SFC_CMD_TRAN_BYTES_SHIFT;
+	if (len) {
+		if (op->data.dir == SPI_MEM_DATA_OUT)
+			cmd |= SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT;
+
+		ctrl |= ((op->data.buswidth >> 1) << SFC_CTRL_DATA_BITS_SHIFT);
+	}
+	if (!len && op->addr.nbytes)
+		cmd |= SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT;
+
+	/* set the Controller */
+	ctrl |= SFC_CTRL_PHASE_SEL_NEGETIVE;
+	cmd |= plat->cs << SFC_CMD_CS_SHIFT;
+
+	writel(ctrl, sfc->regbase + SFC_CTRL);
+	writel(cmd, sfc->regbase + SFC_CMD);
+	if (op->addr.nbytes)
+		writel(op->addr.val, sfc->regbase + SFC_ADDR);
+
+	return 0;
+}
+
+static int rockchip_sfc_write_fifo(struct rockchip_sfc *sfc, const u8 *buf, int len)
+{
+	u8 bytes = len & 0x3;
+	u32 dwords;
+	int tx_level;
+	u32 write_words;
+	u32 tmp = 0;
+
+	dwords = len >> 2;
+	while (dwords) {
+		tx_level = rockchip_sfc_wait_fifo_ready(sfc, SFC_CMD_DIR_WR, 1000);
+		if (tx_level < 0)
+			return tx_level;
+		write_words = min_t(u32, tx_level, dwords);
+		writesl(sfc->regbase + SFC_DATA, buf, write_words);
+		buf += write_words << 2;
+		dwords -= write_words;
+	}
+
+	/* write the rest non word aligned bytes */
+	if (bytes) {
+		tx_level = rockchip_sfc_wait_fifo_ready(sfc, SFC_CMD_DIR_WR, 1000);
+		if (tx_level < 0)
+			return tx_level;
+		memcpy(&tmp, buf, bytes);
+		writel(tmp, sfc->regbase + SFC_DATA);
+	}
+
+	return len;
+}
+
+static int rockchip_sfc_read_fifo(struct rockchip_sfc *sfc, u8 *buf, int len)
+{
+	u8 bytes = len & 0x3;
+	u32 dwords;
+	u8 read_words;
+	int rx_level;
+	int tmp;
+
+	/* word aligned access only */
+	dwords = len >> 2;
+	while (dwords) {
+		rx_level = rockchip_sfc_wait_fifo_ready(sfc, SFC_CMD_DIR_RD, 1000);
+		if (rx_level < 0)
+			return rx_level;
+		read_words = min_t(u32, rx_level, dwords);
+		readsl(sfc->regbase + SFC_DATA, buf, read_words);
+		buf += read_words << 2;
+		dwords -= read_words;
+	}
+
+	/* read the rest non word aligned bytes */
+	if (bytes) {
+		rx_level = rockchip_sfc_wait_fifo_ready(sfc, SFC_CMD_DIR_RD, 1000);
+		if (rx_level < 0)
+			return rx_level;
+		tmp = readl_relaxed(sfc->regbase + SFC_DATA);
+		memcpy(buf, &tmp, bytes);
+	}
+
+	return len;
+}
+
+static int rockchip_sfc_xfer_data_poll(struct rockchip_sfc *sfc,
+				       const struct spi_mem_op *op, u32 len)
+{
+	if (op->data.dir == SPI_MEM_DATA_OUT)
+		return rockchip_sfc_write_fifo(sfc, op->data.buf.out, len);
+	else
+		return rockchip_sfc_read_fifo(sfc, op->data.buf.in, len);
+}
+
+static int rockchip_sfc_exec_mem_op(struct spi_slave *mem,
+				    const struct spi_mem_op *op)
+{
+	struct rockchip_sfc *sfc = dev_get_plat(mem->dev->parent);
+	u32 len = min_t(u32, op->data.nbytes, sfc->max_iosize);
+	struct dm_spi_slave_plat *plat = dev_get_parent_plat(mem->dev);
+	int ret;
+
+	if (unlikely(mem->max_hz != sfc->frequency)) {
+		ret = clk_set_rate(sfc->clk, clamp(mem->max_hz, (uint)SFC_MIN_SPEED_HZ,
+						   (uint)SFC_MAX_SPEED_HZ));
+		if (ret < 0)
+			return ret;
+		sfc->frequency = mem->max_hz;
+	}
+
+	if (unlikely(plat->cs >= SFC_MAX_CHIPSELECT_NUM)) {
+		printf("CS Not Supported for %s: %u\n", mem->dev->parent->name, ret);
+		return -EINVAL;
+	}
+
+	rockchip_sfc_adjust_op_work((struct spi_mem_op *)op);
+
+	rockchip_sfc_xfer_setup(sfc, mem, op, len);
+
+	ret = rockchip_sfc_xfer_data_poll(sfc, op, len);
+
+	if (ret != len) {
+		printf("Transfer of data for %s failed: %u\n", mem->dev->parent->name, ret);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static int rockchip_sfc_adjust_op_size(struct spi_slave *mem, struct spi_mem_op *op)
+{
+	struct rockchip_sfc *sfc = dev_get_plat(mem->dev->parent);
+
+	op->data.nbytes = min(op->data.nbytes, sfc->max_iosize);
+
+	return 0;
+}
+
+static int rockchip_sfc_set_speed(struct udevice *bus, uint speed)
+{
+	/* We set up speed later for each transmission.
+	 */
+	return 0;
+}
+
+static int rockchip_sfc_set_mode(struct udevice *bus, uint mode)
+{
+	return 0;
+}
+
+static const struct spi_controller_mem_ops rockchip_sfc_mem_ops = {
+	.adjust_op_size	= rockchip_sfc_adjust_op_size,
+	.exec_op	= rockchip_sfc_exec_mem_op,
+};
+
+static const struct dm_spi_ops rockchip_sfc_ops = {
+	.mem_ops	= &rockchip_sfc_mem_ops,
+	.set_speed	= rockchip_sfc_set_speed,
+	.set_mode	= rockchip_sfc_set_mode,
+};
+
+static const struct udevice_id rockchip_sfc_ids[] = {
+	{ .compatible = "rockchip,sfc"},
+	{},
+};
+
+U_BOOT_DRIVER(rockchip_sfc_driver) = {
+	.name   = "rockchip_sfc",
+	.id     = UCLASS_SPI,
+	.of_match = rockchip_sfc_ids,
+	.ops    = &rockchip_sfc_ops,
+	.of_to_plat = rockchip_sfc_ofdata_to_platdata,
+	.plat_auto = sizeof(struct rockchip_sfc),
+	.probe  = rockchip_sfc_probe,
+};
-- 
2.25.1



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