summary refs log tree commit diff
path: root/drivers/spi
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 11:45:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-07-30 11:45:52 -0700
commit287dc4b7642df15fa6b9f286c812e79138acd698 (patch)
treec3ebe1caea100ff2b8f414619ec0a9dcd8a14547 /drivers/spi
parent720d85075b7ed3617de8ca8d9097390e303e9f60 (diff)
parent68d8848567ef03eb2c2303173934428d0bf0a531 (diff)
downloadlinux-287dc4b7642df15fa6b9f286c812e79138acd698.tar.gz
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "More hardware support across the field including a bunch of device
  drivers.  The highlight however really are further steps towards
  device tree.

  This has been sitting in -next for ages.  All MIPS _defconfigs have
  been tested to boot or where I don't have hardware available, to at
  least build fine."

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (77 commits)
  MIPS: Loongson 1B: Add defconfig
  MIPS: Loongson 1B: Add board support
  MIPS: Netlogic: early console fix
  MIPS: Netlogic: Fix indentation of smpboot.S
  MIPS: Netlogic: remove cpu_has_dc_aliases define for XLP
  MIPS: Netlogic: Remove unused pcibios_fixups
  MIPS: Netlogic: Add XLP SoC devices in FDT
  MIPS: Netlogic: Add IRQ mappings for more devices
  MIPS: Netlogic: USB support for XLP
  MIPS: Netlogic: XLP PCIe controller support.
  MIPS: Netlogic: Platform changes for XLR/XLS I2C
  MIPS: Netlogic: Platform NAND/NOR flash support
  MIPS: Netlogic: Platform changes for XLS USB
  MIPS: Netlogic: Remove NETLOGIC_ prefix
  MIPS: Netlogic: SMP wakeup code update
  MIPS: Netlogic: Update comments in smpboot.S
  MIPS: BCM63XX: Add 96328avng reference board
  MIPS: Expose PCIe drivers for MIPS
  MIPS: BCM63XX: Add PCIe Support for BCM6328
  MIPS: BCM63XX: Move the PCI initialization into its own function
  ...
Diffstat (limited to 'drivers/spi')
-rw-r--r--drivers/spi/Kconfig9
-rw-r--r--drivers/spi/Makefile1
-rw-r--r--drivers/spi/spi-falcon.c469
3 files changed, 479 insertions, 0 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 4cde4fb0cd6c..5f84b5563c2d 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -144,6 +144,15 @@ config SPI_EP93XX
 	  This enables using the Cirrus EP93xx SPI controller in master
 	  mode.
 
+config SPI_FALCON
+	tristate "Falcon SPI controller support"
+	depends on SOC_FALCON
+	help
+	  The external bus unit (EBU) found on the FALC-ON SoC has SPI
+	  emulation that is designed for serial flash access. This driver
+	  has only been tested with m25p80 type chips. The hardware has no
+	  support for other types of SPI peripherals.
+
 config SPI_GPIO
 	tristate "GPIO-based bitbanging SPI Master"
 	depends on GENERIC_GPIO
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 273f50d1127a..3920dcf4c740 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_SPI_DW_MMIO)		+= spi-dw-mmio.o
 obj-$(CONFIG_SPI_DW_PCI)		+= spi-dw-midpci.o
 spi-dw-midpci-objs			:= spi-dw-pci.o spi-dw-mid.o
 obj-$(CONFIG_SPI_EP93XX)		+= spi-ep93xx.o
+obj-$(CONFIG_SPI_FALCON)		+= spi-falcon.o
 obj-$(CONFIG_SPI_FSL_LIB)		+= spi-fsl-lib.o
 obj-$(CONFIG_SPI_FSL_ESPI)		+= spi-fsl-espi.o
 obj-$(CONFIG_SPI_FSL_SPI)		+= spi-fsl-spi.o
diff --git a/drivers/spi/spi-falcon.c b/drivers/spi/spi-falcon.c
new file mode 100644
index 000000000000..8f6aa735a24c
--- /dev/null
+++ b/drivers/spi/spi-falcon.c
@@ -0,0 +1,469 @@
+/*
+ *  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.
+ *
+ *  Copyright (C) 2012 Thomas Langer <thomas.langer@lantiq.com>
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+#include <linux/workqueue.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+
+#include <lantiq_soc.h>
+
+#define DRV_NAME		"sflash-falcon"
+
+#define FALCON_SPI_XFER_BEGIN	(1 << 0)
+#define FALCON_SPI_XFER_END	(1 << 1)
+
+/* Bus Read Configuration Register0 */
+#define BUSRCON0		0x00000010
+/* Bus Write Configuration Register0 */
+#define BUSWCON0		0x00000018
+/* Serial Flash Configuration Register */
+#define SFCON			0x00000080
+/* Serial Flash Time Register */
+#define SFTIME			0x00000084
+/* Serial Flash Status Register */
+#define SFSTAT			0x00000088
+/* Serial Flash Command Register */
+#define SFCMD			0x0000008C
+/* Serial Flash Address Register */
+#define SFADDR			0x00000090
+/* Serial Flash Data Register */
+#define SFDATA			0x00000094
+/* Serial Flash I/O Control Register */
+#define SFIO			0x00000098
+/* EBU Clock Control Register */
+#define EBUCC			0x000000C4
+
+/* Dummy Phase Length */
+#define SFCMD_DUMLEN_OFFSET	16
+#define SFCMD_DUMLEN_MASK	0x000F0000
+/* Chip Select */
+#define SFCMD_CS_OFFSET		24
+#define SFCMD_CS_MASK		0x07000000
+/* field offset */
+#define SFCMD_ALEN_OFFSET	20
+#define SFCMD_ALEN_MASK		0x00700000
+/* SCK Rise-edge Position */
+#define SFTIME_SCKR_POS_OFFSET	8
+#define SFTIME_SCKR_POS_MASK	0x00000F00
+/* SCK Period */
+#define SFTIME_SCK_PER_OFFSET	0
+#define SFTIME_SCK_PER_MASK	0x0000000F
+/* SCK Fall-edge Position */
+#define SFTIME_SCKF_POS_OFFSET	12
+#define SFTIME_SCKF_POS_MASK	0x0000F000
+/* Device Size */
+#define SFCON_DEV_SIZE_A23_0	0x03000000
+#define SFCON_DEV_SIZE_MASK	0x0F000000
+/* Read Data Position */
+#define SFTIME_RD_POS_MASK	0x000F0000
+/* Data Output */
+#define SFIO_UNUSED_WD_MASK	0x0000000F
+/* Command Opcode mask */
+#define SFCMD_OPC_MASK		0x000000FF
+/* dlen bytes of data to write */
+#define SFCMD_DIR_WRITE		0x00000100
+/* Data Length offset */
+#define SFCMD_DLEN_OFFSET	9
+/* Command Error */
+#define SFSTAT_CMD_ERR		0x20000000
+/* Access Command Pending */
+#define SFSTAT_CMD_PEND		0x00400000
+/* Frequency set to 100MHz. */
+#define EBUCC_EBUDIV_SELF100	0x00000001
+/* Serial Flash */
+#define BUSRCON0_AGEN_SERIAL_FLASH	0xF0000000
+/* 8-bit multiplexed */
+#define BUSRCON0_PORTW_8_BIT_MUX	0x00000000
+/* Serial Flash */
+#define BUSWCON0_AGEN_SERIAL_FLASH	0xF0000000
+/* Chip Select after opcode */
+#define SFCMD_KEEP_CS_KEEP_SELECTED	0x00008000
+
+#define CLOCK_100M	100000000
+#define CLOCK_50M	50000000
+
+struct falcon_sflash {
+	u32 sfcmd; /* for caching of opcode, direction, ... */
+	struct spi_master *master;
+};
+
+int falcon_sflash_xfer(struct spi_device *spi, struct spi_transfer *t,
+		unsigned long flags)
+{
+	struct device *dev = &spi->dev;
+	struct falcon_sflash *priv = spi_master_get_devdata(spi->master);
+	const u8 *txp = t->tx_buf;
+	u8 *rxp = t->rx_buf;
+	unsigned int bytelen = ((8 * t->len + 7) / 8);
+	unsigned int len, alen, dumlen;
+	u32 val;
+	enum {
+		state_init,
+		state_command_prepare,
+		state_write,
+		state_read,
+		state_disable_cs,
+		state_end
+	} state = state_init;
+
+	do {
+		switch (state) {
+		case state_init: /* detect phase of upper layer sequence */
+		{
+			/* initial write ? */
+			if (flags & FALCON_SPI_XFER_BEGIN) {
+				if (!txp) {
+					dev_err(dev,
+						"BEGIN without tx data!\n");
+					return -ENODATA;
+				}
+				/*
+				 * Prepare the parts of the sfcmd register,
+				 * which should not change during a sequence!
+				 * Only exception are the length fields,
+				 * especially alen and dumlen.
+				 */
+
+				priv->sfcmd = ((spi->chip_select
+						<< SFCMD_CS_OFFSET)
+					       & SFCMD_CS_MASK);
+				priv->sfcmd |= SFCMD_KEEP_CS_KEEP_SELECTED;
+				priv->sfcmd |= *txp;
+				txp++;
+				bytelen--;
+				if (bytelen) {
+					/*
+					 * more data:
+					 * maybe address and/or dummy
+					 */
+					state = state_command_prepare;
+					break;
+				} else {
+					dev_dbg(dev, "write cmd %02X\n",
+						priv->sfcmd & SFCMD_OPC_MASK);
+				}
+			}
+			/* continued write ? */
+			if (txp && bytelen) {
+				state = state_write;
+				break;
+			}
+			/* read data? */
+			if (rxp && bytelen) {
+				state = state_read;
+				break;
+			}
+			/* end of sequence? */
+			if (flags & FALCON_SPI_XFER_END)
+				state = state_disable_cs;
+			else
+				state = state_end;
+			break;
+		}
+		/* collect tx data for address and dummy phase */
+		case state_command_prepare:
+		{
+			/* txp is valid, already checked */
+			val = 0;
+			alen = 0;
+			dumlen = 0;
+			while (bytelen > 0) {
+				if (alen < 3) {
+					val = (val << 8) | (*txp++);
+					alen++;
+				} else if ((dumlen < 15) && (*txp == 0)) {
+					/*
+					 * assume dummy bytes are set to 0
+					 * from upper layer
+					 */
+					dumlen++;
+					txp++;
+				} else {
+					break;
+				}
+				bytelen--;
+			}
+			priv->sfcmd &= ~(SFCMD_ALEN_MASK | SFCMD_DUMLEN_MASK);
+			priv->sfcmd |= (alen << SFCMD_ALEN_OFFSET) |
+					 (dumlen << SFCMD_DUMLEN_OFFSET);
+			if (alen > 0)
+				ltq_ebu_w32(val, SFADDR);
+
+			dev_dbg(dev, "wr %02X, alen=%d (addr=%06X) dlen=%d\n",
+				priv->sfcmd & SFCMD_OPC_MASK,
+				alen, val, dumlen);
+
+			if (bytelen > 0) {
+				/* continue with write */
+				state = state_write;
+			} else if (flags & FALCON_SPI_XFER_END) {
+				/* end of sequence? */
+				state = state_disable_cs;
+			} else {
+				/*
+				 * go to end and expect another
+				 * call (read or write)
+				 */
+				state = state_end;
+			}
+			break;
+		}
+		case state_write:
+		{
+			/* txp still valid */
+			priv->sfcmd |= SFCMD_DIR_WRITE;
+			len = 0;
+			val = 0;
+			do {
+				if (bytelen--)
+					val |= (*txp++) << (8 * len++);
+				if ((flags & FALCON_SPI_XFER_END)
+				    && (bytelen == 0)) {
+					priv->sfcmd &=
+						~SFCMD_KEEP_CS_KEEP_SELECTED;
+				}
+				if ((len == 4) || (bytelen == 0)) {
+					ltq_ebu_w32(val, SFDATA);
+					ltq_ebu_w32(priv->sfcmd
+						| (len<<SFCMD_DLEN_OFFSET),
+						SFCMD);
+					len = 0;
+					val = 0;
+					priv->sfcmd &= ~(SFCMD_ALEN_MASK
+							 | SFCMD_DUMLEN_MASK);
+				}
+			} while (bytelen);
+			state = state_end;
+			break;
+		}
+		case state_read:
+		{
+			/* read data */
+			priv->sfcmd &= ~SFCMD_DIR_WRITE;
+			do {
+				if ((flags & FALCON_SPI_XFER_END)
+				    && (bytelen <= 4)) {
+					priv->sfcmd &=
+						~SFCMD_KEEP_CS_KEEP_SELECTED;
+				}
+				len = (bytelen > 4) ? 4 : bytelen;
+				bytelen -= len;
+				ltq_ebu_w32(priv->sfcmd
+					| (len << SFCMD_DLEN_OFFSET), SFCMD);
+				priv->sfcmd &= ~(SFCMD_ALEN_MASK
+						 | SFCMD_DUMLEN_MASK);
+				do {
+					val = ltq_ebu_r32(SFSTAT);
+					if (val & SFSTAT_CMD_ERR) {
+						/* reset error status */
+						dev_err(dev, "SFSTAT: CMD_ERR");
+						dev_err(dev, " (%x)\n", val);
+						ltq_ebu_w32(SFSTAT_CMD_ERR,
+							SFSTAT);
+						return -EBADE;
+					}
+				} while (val & SFSTAT_CMD_PEND);
+				val = ltq_ebu_r32(SFDATA);
+				do {
+					*rxp = (val & 0xFF);
+					rxp++;
+					val >>= 8;
+					len--;
+				} while (len);
+			} while (bytelen);
+			state = state_end;
+			break;
+		}
+		case state_disable_cs:
+		{
+			priv->sfcmd &= ~SFCMD_KEEP_CS_KEEP_SELECTED;
+			ltq_ebu_w32(priv->sfcmd | (0 << SFCMD_DLEN_OFFSET),
+				SFCMD);
+			val = ltq_ebu_r32(SFSTAT);
+			if (val & SFSTAT_CMD_ERR) {
+				/* reset error status */
+				dev_err(dev, "SFSTAT: CMD_ERR (%x)\n", val);
+				ltq_ebu_w32(SFSTAT_CMD_ERR, SFSTAT);
+				return -EBADE;
+			}
+			state = state_end;
+			break;
+		}
+		case state_end:
+			break;
+		}
+	} while (state != state_end);
+
+	return 0;
+}
+
+static int falcon_sflash_setup(struct spi_device *spi)
+{
+	unsigned int i;
+	unsigned long flags;
+
+	if (spi->chip_select > 0)
+		return -ENODEV;
+
+	spin_lock_irqsave(&ebu_lock, flags);
+
+	if (spi->max_speed_hz >= CLOCK_100M) {
+		/* set EBU clock to 100 MHz */
+		ltq_sys1_w32_mask(0, EBUCC_EBUDIV_SELF100, EBUCC);
+		i = 1; /* divider */
+	} else {
+		/* set EBU clock to 50 MHz */
+		ltq_sys1_w32_mask(EBUCC_EBUDIV_SELF100, 0, EBUCC);
+
+		/* search for suitable divider */
+		for (i = 1; i < 7; i++) {
+			if (CLOCK_50M / i <= spi->max_speed_hz)
+				break;
+		}
+	}
+
+	/* setup period of serial clock */
+	ltq_ebu_w32_mask(SFTIME_SCKF_POS_MASK
+		     | SFTIME_SCKR_POS_MASK
+		     | SFTIME_SCK_PER_MASK,
+		     (i << SFTIME_SCKR_POS_OFFSET)
+		     | (i << (SFTIME_SCK_PER_OFFSET + 1)),
+		     SFTIME);
+
+	/*
+	 * set some bits of unused_wd, to not trigger HOLD/WP
+	 * signals on non QUAD flashes
+	 */
+	ltq_ebu_w32((SFIO_UNUSED_WD_MASK & (0x8 | 0x4)), SFIO);
+
+	ltq_ebu_w32(BUSRCON0_AGEN_SERIAL_FLASH | BUSRCON0_PORTW_8_BIT_MUX,
+			BUSRCON0);
+	ltq_ebu_w32(BUSWCON0_AGEN_SERIAL_FLASH, BUSWCON0);
+	/* set address wrap around to maximum for 24-bit addresses */
+	ltq_ebu_w32_mask(SFCON_DEV_SIZE_MASK, SFCON_DEV_SIZE_A23_0, SFCON);
+
+	spin_unlock_irqrestore(&ebu_lock, flags);
+
+	return 0;
+}
+
+static int falcon_sflash_prepare_xfer(struct spi_master *master)
+{
+	return 0;
+}
+
+static int falcon_sflash_unprepare_xfer(struct spi_master *master)
+{
+	return 0;
+}
+
+static int falcon_sflash_xfer_one(struct spi_master *master,
+					struct spi_message *m)
+{
+	struct falcon_sflash *priv = spi_master_get_devdata(master);
+	struct spi_transfer *t;
+	unsigned long spi_flags;
+	unsigned long flags;
+	int ret = 0;
+
+	priv->sfcmd = 0;
+	m->actual_length = 0;
+
+	spi_flags = FALCON_SPI_XFER_BEGIN;
+	list_for_each_entry(t, &m->transfers, transfer_list) {
+		if (list_is_last(&t->transfer_list, &m->transfers))
+			spi_flags |= FALCON_SPI_XFER_END;
+
+		spin_lock_irqsave(&ebu_lock, flags);
+		ret = falcon_sflash_xfer(m->spi, t, spi_flags);
+		spin_unlock_irqrestore(&ebu_lock, flags);
+
+		if (ret)
+			break;
+
+		m->actual_length += t->len;
+
+		WARN_ON(t->delay_usecs || t->cs_change);
+		spi_flags = 0;
+	}
+
+	m->status = ret;
+	m->complete(m->context);
+
+	return 0;
+}
+
+static int __devinit falcon_sflash_probe(struct platform_device *pdev)
+{
+	struct falcon_sflash *priv;
+	struct spi_master *master;
+	int ret;
+
+	if (ltq_boot_select() != BS_SPI) {
+		dev_err(&pdev->dev, "invalid bootstrap options\n");
+		return -ENODEV;
+	}
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*priv));
+	if (!master)
+		return -ENOMEM;
+
+	priv = spi_master_get_devdata(master);
+	priv->master = master;
+
+	master->mode_bits = SPI_MODE_3;
+	master->num_chipselect = 1;
+	master->bus_num = -1;
+	master->setup = falcon_sflash_setup;
+	master->prepare_transfer_hardware = falcon_sflash_prepare_xfer;
+	master->transfer_one_message = falcon_sflash_xfer_one;
+	master->unprepare_transfer_hardware = falcon_sflash_unprepare_xfer;
+	master->dev.of_node = pdev->dev.of_node;
+
+	platform_set_drvdata(pdev, priv);
+
+	ret = spi_register_master(master);
+	if (ret)
+		spi_master_put(master);
+	return ret;
+}
+
+static int __devexit falcon_sflash_remove(struct platform_device *pdev)
+{
+	struct falcon_sflash *priv = platform_get_drvdata(pdev);
+
+	spi_unregister_master(priv->master);
+
+	return 0;
+}
+
+static const struct of_device_id falcon_sflash_match[] = {
+	{ .compatible = "lantiq,sflash-falcon" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, falcon_sflash_match);
+
+static struct platform_driver falcon_sflash_driver = {
+	.probe	= falcon_sflash_probe,
+	.remove	= __devexit_p(falcon_sflash_remove),
+	.driver = {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+		.of_match_table = falcon_sflash_match,
+	}
+};
+
+module_platform_driver(falcon_sflash_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Lantiq Falcon SPI/SFLASH controller driver");