[PATCH 1/2] mtd: spi-nor: add driver for NXP SPI Flash Interface (SPIFI)

Joachim Eastwood
2015-05-29T17:50:15Z

Add SPI-NOR driver for the SPI Flash Interface (SPIFI)
controller that is found newer NXP MCU devices.

The controller supports serial SPI Flash devices with 1-, 2-
and 4-bit width in either SPI mode 0 or 3. The controller
can operate in either command or memory mode. In memory mode
the Flash is exposed as normal memory and can be directly
accessed by the CPU.

Signed-off-by: Joachim Eastwood <manabian@gmail.com>
---
drivers/mtd/spi-nor/Kconfig | 10 +
drivers/mtd/spi-nor/Makefile | 1 +
drivers/mtd/spi-nor/nxp-spifi.c | 508 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 519 insertions(+)
create mode 100644 drivers/mtd/spi-nor/nxp-spifi.c

diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 64a4f0edabc7..f10a37f1a4ef 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -28,4 +28,14 @@ config SPI_FSL_QUADSPI
This enables support for the Quad SPI controller in master mode.
We only connect the NOR to this controller now.

+config SPI_NXP_SPIFI
+ tristate "NXP SPI Flash Interface (SPIFI)"
+ depends on OF && (ARCH_LPC18XX || COMPILE_TEST)
+ help
+ Enable support for the NXP LPC SPI Flash Interface controller.
+
+ SPIFI is a specialized controller for connecting serial SPI
+ Flash. Enable this option if you have a device with a SPIFI
+ controller and want to access the Flash as a mtd device.
+
endif # MTD_SPI_NOR
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
index 6a7ce1462247..e53333ef8582 100644
--- a/drivers/mtd/spi-nor/Makefile
+++ b/drivers/mtd/spi-nor/Makefile
@@ -1,2 +1,3 @@
obj-$(CONFIG_MTD_SPI_NOR) += spi-nor.o
obj-$(CONFIG_SPI_FSL_QUADSPI) += fsl-quadspi.o
+obj-$(CONFIG_SPI_NXP_SPIFI) += nxp-spifi.o
diff --git a/drivers/mtd/spi-nor/nxp-spifi.c b/drivers/mtd/spi-nor/nxp-spifi.c
new file mode 100644
index 000000000000..cbfe0bb16f81
--- /dev/null
+++ b/drivers/mtd/spi-nor/nxp-spifi.c
@@ -0,0 +1,508 @@
+/*
+ * SPI-NOR driver for NXP SPI Flash Interface (SPIFI)
+ *
+ * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * Based on Freescale QuadSPI driver:
+ * Copyright (C) 2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+
+/* NXP SPIFI registers, bits and macros */
+#define SPIFI_CTRL 0x000
+#define SPIFI_CTRL_TIMEOUT(timeout) (timeout)
+#define SPIFI_CTRL_CSHIGH(cshigh) ((cshigh) << 16)
+#define SPIFI_CTRL_MODE3 BIT(23)
+#define SPIFI_CTRL_DUAL BIT(28)
+#define SPIFI_CTRL_FBCLK BIT(30)
+#define SPIFI_CMD 0x004
+#define SPIFI_CMD_DATALEN(dlen) (dlen & 0x3fff)
+#define SPIFI_CMD_DOUT BIT(15)
+#define SPIFI_CMD_INTLEN(ilen) ((ilen) << 16)
+#define SPIFI_CMD_FIELDFORM(field) ((field) << 19)
+#define SPIFI_CMD_FIELDFORM_ALL_SERIAL SPIFI_CMD_FIELDFORM(0x0)
+#define SPIFI_CMD_FIELDFORM_QUAD_DUAL_DATA SPIFI_CMD_FIELDFORM(0x1)
+#define SPIFI_CMD_FRAMEFORM(frame) ((frame) << 21)
+#define SPIFI_CMD_FRAMEFORM_OPCODE_ONLY SPIFI_CMD_FRAMEFORM(0x1)
+#define SPIFI_CMD_OPCODE(op) ((op) << 24)
+#define SPIFI_ADDR 0x008
+#define SPIFI_IDATA 0x00c
+#define SPIFI_CLIMIT 0x010
+#define SPIFI_DATA 0x014
+#define SPIFI_MCMD 0x018
+#define SPIFI_STAT 0x01c
+#define SPIFI_STAT_MCINIT BIT(0)
+#define SPIFI_STAT_CMD BIT(1)
+#define SPIFI_STAT_RESET BIT(4)
+
+#define SPI_NOR_MAX_ID_LEN 6
+
+struct nxp_spifi {
+ struct device *dev;
+ struct clk *clk_spifi;
+ struct clk *clk_reg;
+ void __iomem *io_base;
+ void __iomem *flash_base;
+ struct mtd_info mtd;
+ struct spi_nor nor;
+ u32 mcmd;
+};
+
+static int nxp_spifi_wait_for_event(struct nxp_spifi *spifi, u32 event)
+{
+ int retry = 3;
+ u32 stat;
+
+ do {
+ stat = readb(spifi->io_base + SPIFI_STAT);
+ if (!(stat & event))
+ return 0;
+
+ udelay(10);
+ } while (retry--);
+
+ return -ETIMEDOUT;
+}
+
+static int nxp_spifi_wait_for_cmd(struct nxp_spifi *spifi)
+{
+ int ret;
+
+ ret = nxp_spifi_wait_for_event(spifi, SPIFI_STAT_CMD);
+ if (ret)
+ dev_warn(spifi->dev, "command timed out\n");
+
+ return ret;
+}
+
+static int nxp_spifi_reset(struct nxp_spifi *spifi)
+{
+ int ret;
+
+ writel(SPIFI_STAT_RESET, spifi->io_base + SPIFI_STAT);
+ ret = nxp_spifi_wait_for_event(spifi, SPIFI_STAT_RESET);
+ if (ret)
+ dev_warn(spifi->dev, "state reset timed out\n");
+
+ return ret;
+}
+
+static int nxp_spifi_set_memory_mode_off(struct nxp_spifi *spifi)
+{
+ u32 stat;
+ int ret;
+
+ stat = readb(spifi->io_base + SPIFI_STAT);
+ if (!(stat & SPIFI_STAT_MCINIT))
+ return 0;
+
+ ret = nxp_spifi_reset(spifi);
+ if (ret)
+ dev_err(spifi->dev, "unable to enter command mode\n");
+
+ return ret;
+}
+
+static int nxp_spifi_set_memory_mode_on(struct nxp_spifi *spifi)
+{
+ int retry = 3;
+ u32 stat;
+
+ stat = readb(spifi->io_base + SPIFI_STAT);
+ if (stat & SPIFI_STAT_MCINIT)
+ return 0;
+
+ writel(spifi->mcmd, spifi->io_base + SPIFI_MCMD);
+
+ do {
+ stat = readb(spifi->io_base + SPIFI_STAT);
+ if (stat & SPIFI_STAT_MCINIT)
+ return 0;
+
+ udelay(10);
+ } while (retry--);
+
+ dev_err(spifi->dev, "unable to enter memory mode\n");
+
+ return -ETIMEDOUT;
+}
+
+static int nxp_spifi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+ struct nxp_spifi *spifi = nor->priv;
+ u32 cmd;
+ int ret;
+
+ ret = nxp_spifi_set_memory_mode_off(spifi);
+ if (ret)
+ return ret;
+
+ cmd = SPIFI_CMD_DATALEN(len) |
+ SPIFI_CMD_OPCODE(opcode) |
+ SPIFI_CMD_FIELDFORM_ALL_SERIAL |
+ SPIFI_CMD_FRAMEFORM_OPCODE_ONLY;
+ writel(cmd, spifi->io_base + SPIFI_CMD);
+
+ while (len--)
+ *buf++ = readb(spifi->io_base + SPIFI_DATA);
+
+ return nxp_spifi_wait_for_cmd(spifi);
+}
+
+static int nxp_spifi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf,
+ int len, int write_enable)
+{
+ struct nxp_spifi *spifi = nor->priv;
+ u32 cmd;
+ int ret;
+
+ ret = nxp_spifi_set_memory_mode_off(spifi);
+ if (ret)
+ return ret;
+
+ cmd = SPIFI_CMD_DOUT |
+ SPIFI_CMD_DATALEN(len) |
+ SPIFI_CMD_OPCODE(opcode) |
+ SPIFI_CMD_FIELDFORM_ALL_SERIAL |
+ SPIFI_CMD_FRAMEFORM_OPCODE_ONLY;
+ writel(cmd, spifi->io_base + SPIFI_CMD);
+
+ while (len--)
+ writeb(*buf++, spifi->io_base + SPIFI_DATA);
+
+ return nxp_spifi_wait_for_cmd(spifi);
+}
+
+static int nxp_spifi_read(struct spi_nor *nor, loff_t from, size_t len,
+ size_t *retlen, u_char *buf)
+{
+ struct nxp_spifi *spifi = nor->priv;
+ int ret;
+
+ ret = nxp_spifi_set_memory_mode_on(spifi);
+ if (ret)
+ return ret;
+
+ memcpy_fromio(buf, spifi->flash_base + from, len);
+ *retlen += len;
+
+ return 0;
+}
+
+static void nxp_spifi_write(struct spi_nor *nor, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ struct nxp_spifi *spifi = nor->priv;
+ u32 cmd;
+ int ret;
+
+ ret = nxp_spifi_set_memory_mode_off(spifi);
+ if (ret) {
+ *retlen = 0;
+ return;
+ }
+
+ writel(to, spifi->io_base + SPIFI_ADDR);
+ *retlen = len;
+
+ cmd = SPIFI_CMD_DOUT |
+ SPIFI_CMD_DATALEN(len) |
+ SPIFI_CMD_FIELDFORM_ALL_SERIAL |
+ SPIFI_CMD_OPCODE(nor->program_opcode) |
+ SPIFI_CMD_FRAMEFORM(spifi->nor.addr_width + 1);
+ writel(cmd, spifi->io_base + SPIFI_CMD);
+
+ while (len--)
+ writeb(*buf++, spifi->io_base + SPIFI_DATA);
+
+ nxp_spifi_wait_for_cmd(spifi);
+}
+
+static int nxp_spifi_erase(struct spi_nor *nor, loff_t offs)
+{
+ struct nxp_spifi *spifi = nor->priv;
+ u32 cmd;
+ int ret;
+
+ ret = nxp_spifi_set_memory_mode_off(spifi);
+ if (ret)
+ return ret;
+
+ writel(offs, spifi->io_base + SPIFI_ADDR);
+
+ cmd = SPIFI_CMD_FIELDFORM_ALL_SERIAL |
+ SPIFI_CMD_OPCODE(nor->erase_opcode) |
+ SPIFI_CMD_FRAMEFORM(spifi->nor.addr_width + 1);
+ writel(cmd, spifi->io_base + SPIFI_CMD);
+
+ return nxp_spifi_wait_for_cmd(spifi);
+}
+
+static int nxp_spifi_setup_memory_cmd(struct nxp_spifi *spifi)
+{
+ switch (spifi->nor.flash_read) {
+ case SPI_NOR_NORMAL:
+ case SPI_NOR_FAST:
+ spifi->mcmd = SPIFI_CMD_FIELDFORM_ALL_SERIAL;
+ break;
+ case SPI_NOR_DUAL:
+ case SPI_NOR_QUAD:
+ spifi->mcmd = SPIFI_CMD_FIELDFORM_QUAD_DUAL_DATA;
+ break;
+ default:
+ dev_err(spifi->dev, "unsupported spi read mode\n");
+ return -EINVAL;
+ }
+
+ /* Memory mode supports address length between 1 and 4 */
+ if (spifi->nor.addr_width < 1 || spifi->nor.addr_width > 4)
+ return -EINVAL;
+
+ spifi->mcmd |= SPIFI_CMD_OPCODE(spifi->nor.read_opcode) |
+ SPIFI_CMD_INTLEN(spifi->nor.read_dummy / 8) |
+ SPIFI_CMD_FRAMEFORM(spifi->nor.addr_width + 1);
+
+ return 0;
+}
+
+static void nxp_spifi_dummy_id_read(struct spi_nor *nor)
+{
+ u8 id[SPI_NOR_MAX_ID_LEN];
+ nor->read_reg(nor, SPINOR_OP_RDID, id, SPI_NOR_MAX_ID_LEN);
+}
+
+static int nxp_spifi_setup_flash(struct nxp_spifi *spifi,
+ struct device_node *np)
+{
+ struct mtd_part_parser_data ppdata;
+ enum read_mode flash_read;
+ u32 ctrl, property;
+ char modalias[40];
+ u16 mode = 0;
+ int ret;
+
+ if (!of_property_read_u32(np, "spi-rx-bus-width", &property)) {
+ switch (property) {
+ case 1:
+ break;
+ case 2:
+ mode |= SPI_RX_DUAL;
+ break;
+ case 4:
+ mode |= SPI_RX_QUAD;
+ break;
+ default:
+ dev_err(spifi->dev, "unsupported rx-bus-width\n");
+ return -EINVAL;
+ }
+ }
+
+ if (of_find_property(np, "spi-cpha", NULL))
+ mode |= SPI_CPHA;
+
+ if (of_find_property(np, "spi-cpol", NULL))
+ mode |= SPI_CPOL;
+
+ /* Setup control register defaults */
+ ctrl = SPIFI_CTRL_TIMEOUT(1000) |
+ SPIFI_CTRL_CSHIGH(15) |
+ SPIFI_CTRL_FBCLK;
+
+ if (mode & SPI_RX_DUAL) {
+ ctrl |= SPIFI_CTRL_DUAL;
+ flash_read = SPI_NOR_DUAL;
+ } else if (mode & SPI_RX_QUAD) {
+ ctrl &= ~SPIFI_CTRL_DUAL;
+ flash_read = SPI_NOR_QUAD;
+ } else {
+ ctrl |= SPIFI_CTRL_DUAL;
+ flash_read = SPI_NOR_NORMAL;
+ }
+
+ switch (mode & (SPI_CPHA | SPI_CPOL)) {
+ case SPI_MODE_0:
+ ctrl &= ~SPIFI_CTRL_MODE3;
+ break;
+ case SPI_MODE_3:
+ ctrl |= SPIFI_CTRL_MODE3;
+ break;
+ default:
+ dev_err(spifi->dev, "only mode 0 and 3 supported\n");
+ return -EINVAL;
+ }
+
+ writel(ctrl, spifi->io_base + SPIFI_CTRL);
+ dev_info(spifi->dev, "spifi ctrl = 0x%08x\n", ctrl);
+
+ spifi->mtd.priv = &spifi->nor;
+ spifi->nor.mtd = &spifi->mtd;
+ spifi->nor.dev = spifi->dev;
+ spifi->nor.priv = spifi;
+ spifi->nor.read = nxp_spifi_read;
+ spifi->nor.write = nxp_spifi_write;
+ spifi->nor.erase = nxp_spifi_erase;
+ spifi->nor.read_reg = nxp_spifi_read_reg;
+ spifi->nor.write_reg = nxp_spifi_write_reg;
+
+ ret = of_modalias_node(np, modalias, sizeof(modalias));
+ if (ret < 0) {
+ dev_err(spifi->dev, "unable to get device modalias\n");
+ return ret;
+ }
+
+ /*
+ * The first read on a hard reset isn't reliable so do a
+ * dummy read of the id before calling spi_nor_scan().
+ * The reason for this problem is unknown.
+ *
+ * The official NXP spifilib uses more or less the same
+ * workaround that is applied here by reading the device
+ * id multiple times.
+ */
+ nxp_spifi_dummy_id_read(&spifi->nor);
+
+ ret = spi_nor_scan(&spifi->nor, modalias, flash_read);
+ if (ret) {
+ dev_err(spifi->dev, "device scan failed\n");
+ return ret;
+ }
+
+ ret = nxp_spifi_setup_memory_cmd(spifi);
+ if (ret) {
+ dev_err(spifi->dev, "memory command setup failed\n");
+ return ret;
+ }
+
+ ppdata.of_node = np;
+ ret = mtd_device_parse_register(&spifi->mtd, NULL, &ppdata, NULL, 0);
+ if (ret) {
+ dev_err(spifi->dev, "mtd device parse failed\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int nxp_spifi_probe(struct platform_device *pdev)
+{
+ struct device_node *flash_np;
+ struct nxp_spifi *spifi;
+ struct resource *res;
+ int ret;
+
+ spifi = devm_kzalloc(&pdev->dev, sizeof(*spifi), GFP_KERNEL);
+ if (!spifi)
+ return -ENOMEM;
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "spifi");
+ spifi->io_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(spifi->io_base))
+ return PTR_ERR(spifi->io_base);
+
+ res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "flash");
+ spifi->flash_base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(spifi->flash_base))
+ return PTR_ERR(spifi->flash_base);
+
+ spifi->clk_spifi = devm_clk_get(&pdev->dev, "spifi");
+ if (IS_ERR(spifi->clk_spifi)) {
+ dev_err(&pdev->dev, "spifi clock not found\n");
+ return PTR_ERR(spifi->clk_spifi);
+ }
+
+ spifi->clk_reg = devm_clk_get(&pdev->dev, "reg");
+ if (IS_ERR(spifi->clk_reg)) {
+ dev_err(&pdev->dev, "reg clock not found\n");
+ return PTR_ERR(spifi->clk_reg);
+ }
+
+ ret = clk_prepare_enable(spifi->clk_reg);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to enable reg clock\n");
+ return ret;
+ }
+
+ ret = clk_prepare_enable(spifi->clk_spifi);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to enable spifi clock\n");
+ goto dis_clk_reg;
+ }
+
+ spifi->dev = &pdev->dev;
+ platform_set_drvdata(pdev, spifi);
+
+ /* Initialize and reset device */
+ nxp_spifi_reset(spifi);
+ writel(0, spifi->io_base + SPIFI_IDATA);
+ writel(0, spifi->io_base + SPIFI_MCMD);
+ nxp_spifi_reset(spifi);
+
+ flash_np = of_get_next_available_child(pdev->dev.of_node, NULL);
+ if (!flash_np) {
+ dev_err(&pdev->dev, "no spi flash device to configure\n");
+ ret = -ENODEV;
+ goto dis_clks;
+ }
+
+ ret = nxp_spifi_setup_flash(spifi, flash_np);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to setup flash chip\n");
+ goto dis_clks;
+ }
+
+ return 0;
+
+dis_clks:
+ clk_disable_unprepare(spifi->clk_spifi);
+dis_clk_reg:
+ clk_disable_unprepare(spifi->clk_reg);
+ return ret;
+}
+
+static int nxp_spifi_remove(struct platform_device *pdev)
+{
+ struct nxp_spifi *spifi = platform_get_drvdata(pdev);
+
+ mtd_device_unregister(&spifi->mtd);
+ clk_disable_unprepare(spifi->clk_spifi);
+ clk_disable_unprepare(spifi->clk_reg);
+
+ return 0;
+}
+
+static const struct of_device_id nxp_spifi_match[] = {
+ {.compatible = "nxp,lpc1773-spifi"},
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, nxp_spifi_match);
+
+static struct platform_driver nxp_spifi_driver = {
+ .probe = nxp_spifi_probe,
+ .remove = nxp_spifi_remove,
+ .driver = {
+ .name = "nxp-spifi",
+ .of_match_table = nxp_spifi_match,
+ },
+};
+module_platform_driver(nxp_spifi_driver);
+
+MODULE_DESCRIPTION("NXP SPI Flash Interface driver");
+MODULE_AUTHOR("Joachim Eastwood <manabian@gmail.com>");
+MODULE_LICENSE("GPL v2");
--
1.8.0