Openwrt/target/linux/brcm2708/patches-3.18/0019-Add-Chris-Boot-s-i2c-and-spi-drivers.patch

From 66ea263246ca6dd9f63dce8fb22157fa83693300 Mon Sep 17 00:00:00 2001
From: popcornmix <popcornmix@gmail.com>
Date: Mon, 4 Nov 2013 18:56:10 +0000
Subject: [PATCH 019/114] Add Chris Boot's i2c and spi drivers.

i2c-bcm2708: fixed baudrate

Fixed issue where the wrong CDIV value was set for baudrates below 3815 Hz (for 250MHz bus clock).
In that case the computed CDIV value was more than 0xffff. However the CDIV register width is only 16 bits.
This resulted in incorrect setting of CDIV and higher baudrate than intended.
Example: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0x1704 -> 42430Hz
After correction: 3500Hz -> CDIV=0x11704 -> CDIV(16bit)=0xffff -> 3815Hz
The correct baudrate is shown in the log after the cdiv > 0xffff correction.
---
 arch/arm/configs/bcmrpi_defconfig |   7 +
 arch/arm/mach-bcm2708/Kconfig     |   7 +
 arch/arm/mach-bcm2708/bcm2708.c   | 104 ++++++-
 drivers/i2c/busses/Kconfig        |  19 ++
 drivers/i2c/busses/Makefile       |   1 +
 drivers/i2c/busses/i2c-bcm2708.c  | 420 +++++++++++++++++++++++++
 drivers/spi/Kconfig               |   8 +
 drivers/spi/Makefile              |   1 +
 drivers/spi/spi-bcm2708.c         | 626 ++++++++++++++++++++++++++++++++++++++
 9 files changed, 1191 insertions(+), 2 deletions(-)
 create mode 100644 drivers/i2c/busses/i2c-bcm2708.c
 create mode 100644 drivers/spi/spi-bcm2708.c

--- a/arch/arm/configs/bcmrpi_defconfig
+++ b/arch/arm/configs/bcmrpi_defconfig
@@ -195,6 +195,13 @@ CONFIG_SERIAL_AMBA_PL011=y
 CONFIG_SERIAL_AMBA_PL011_CONSOLE=y
 # CONFIG_HW_RANDOM is not set
 CONFIG_RAW_DRIVER=y
+CONFIG_I2C=y
+CONFIG_I2C_CHARDEV=m
+CONFIG_I2C_BCM2708=m
+CONFIG_SPI=y
+CONFIG_SPI_BCM2708=m
+CONFIG_SPI_SPIDEV=m
+CONFIG_GPIO_SYSFS=y
 # CONFIG_HWMON is not set
 CONFIG_WATCHDOG=y
 CONFIG_FB=y
--- a/arch/arm/mach-bcm2708/Kconfig
+++ b/arch/arm/mach-bcm2708/Kconfig
@@ -31,4 +31,11 @@ config BCM2708_NOL2CACHE
         help
           Do not allow ARM to use GPU's L2 cache. Requires disable_l2cache in config.txt.
 
+config BCM2708_SPIDEV
+	bool "Bind spidev to SPI0 master"
+	depends on MACH_BCM2708
+	depends on SPI
+	default y
+	help
+	  Binds spidev driver to the SPI0 master
 endmenu
--- a/arch/arm/mach-bcm2708/bcm2708.c
+++ b/arch/arm/mach-bcm2708/bcm2708.c
@@ -31,6 +31,7 @@
 #include <linux/cnt32_to_63.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/spi/spi.h>
 
 #include <linux/version.h>
 #include <linux/clkdev.h>
@@ -205,7 +206,6 @@ static struct clk osc_clk = {
 
 /* warning - the USB needs a clock > 34MHz */
 
-#ifdef CONFIG_MMC_BCM2708
 static struct clk sdhost_clk = {
 #ifdef CONFIG_ARCH_BCM2708_CHIPIT
 	.rate = 4000000,	/* 4MHz */
@@ -213,7 +213,6 @@ static struct clk sdhost_clk = {
 	.rate = 250000000,	/* 250MHz */
 #endif
 };
-#endif
 
 static struct clk_lookup lookups[] = {
 	{			/* UART0 */
@@ -223,6 +222,15 @@ static struct clk_lookup lookups[] = {
 	{			/* USB */
 	 .dev_id = "bcm2708_usb",
 	 .clk = &osc_clk,
+	 }, {	/* SPI */
+		 .dev_id = "bcm2708_spi.0",
+		 .clk = &sdhost_clk,
+	 }, {	/* BSC0 */
+		 .dev_id = "bcm2708_i2c.0",
+		 .clk = &sdhost_clk,
+	 }, {	/* BSC1 */
+		 .dev_id = "bcm2708_i2c.1",
+		 .clk = &sdhost_clk,
 	 }
 };
 
@@ -455,6 +463,89 @@ static struct platform_device bcm2708_al
 	       },
 };
 
+static struct resource bcm2708_spi_resources[] = {
+	{
+		.start = SPI0_BASE,
+		.end = SPI0_BASE + SZ_256 - 1,
+		.flags = IORESOURCE_MEM,
+	}, {
+		.start = IRQ_SPI,
+		.end = IRQ_SPI,
+		.flags = IORESOURCE_IRQ,
+	}
+};
+
+
+static u64 bcm2708_spi_dmamask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON);
+static struct platform_device bcm2708_spi_device = {
+	.name = "bcm2708_spi",
+	.id = 0,
+	.num_resources = ARRAY_SIZE(bcm2708_spi_resources),
+	.resource = bcm2708_spi_resources,
+	.dev = {
+		.dma_mask = &bcm2708_spi_dmamask,
+		.coherent_dma_mask = DMA_BIT_MASK(DMA_MASK_BITS_COMMON)},
+};
+
+#ifdef CONFIG_BCM2708_SPIDEV
+static struct spi_board_info bcm2708_spi_devices[] = {
+#ifdef CONFIG_SPI_SPIDEV
+	{
+		.modalias = "spidev",
+		.max_speed_hz = 500000,
+		.bus_num = 0,
+		.chip_select = 0,
+		.mode = SPI_MODE_0,
+	}, {
+		.modalias = "spidev",
+		.max_speed_hz = 500000,
+		.bus_num = 0,
+		.chip_select = 1,
+		.mode = SPI_MODE_0,
+	}
+#endif
+};
+#endif
+
+static struct resource bcm2708_bsc0_resources[] = {
+	{
+		.start = BSC0_BASE,
+		.end = BSC0_BASE + SZ_256 - 1,
+		.flags = IORESOURCE_MEM,
+	}, {
+		.start = INTERRUPT_I2C,
+		.end = INTERRUPT_I2C,
+		.flags = IORESOURCE_IRQ,
+	}
+};
+
+static struct platform_device bcm2708_bsc0_device = {
+	.name = "bcm2708_i2c",
+	.id = 0,
+	.num_resources = ARRAY_SIZE(bcm2708_bsc0_resources),
+	.resource = bcm2708_bsc0_resources,
+};
+
+
+static struct resource bcm2708_bsc1_resources[] = {
+	{
+		.start = BSC1_BASE,
+		.end = BSC1_BASE + SZ_256 - 1,
+		.flags = IORESOURCE_MEM,
+	}, {
+		.start = INTERRUPT_I2C,
+		.end = INTERRUPT_I2C,
+		.flags = IORESOURCE_IRQ,
+	}
+};
+
+static struct platform_device bcm2708_bsc1_device = {
+	.name = "bcm2708_i2c",
+	.id = 1,
+	.num_resources = ARRAY_SIZE(bcm2708_bsc1_resources),
+	.resource = bcm2708_bsc1_resources,
+};
+
 static struct platform_device bcm2835_hwmon_device = {
 	.name = "bcm2835_hwmon",
 };
@@ -571,6 +662,10 @@ void __init bcm2708_init(void)
 	for (i = 0; i < ARRAY_SIZE(bcm2708_alsa_devices); i++)
 		bcm_register_device(&bcm2708_alsa_devices[i]);
 
+	bcm_register_device(&bcm2708_spi_device);
+	bcm_register_device(&bcm2708_bsc0_device);
+	bcm_register_device(&bcm2708_bsc1_device);
+
 	bcm_register_device(&bcm2835_hwmon_device);
 	bcm_register_device(&bcm2835_thermal_device);
 
@@ -580,6 +675,11 @@ void __init bcm2708_init(void)
 	}
 	system_rev = boardrev;
 	system_serial_low = serial;
+
+#ifdef CONFIG_BCM2708_SPIDEV
+	spi_register_board_info(bcm2708_spi_devices,
+			ARRAY_SIZE(bcm2708_spi_devices));
+#endif
 }
 
 static void timer_set_mode(enum clock_event_mode mode,
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -371,6 +371,25 @@ config I2C_BCM2835
 	  This support is also available as a module.  If so, the module
 	  will be called i2c-bcm2835.
 
+config I2C_BCM2708
+	tristate "BCM2708 BSC"
+	depends on MACH_BCM2708
+	help
+	  Enabling this option will add BSC (Broadcom Serial Controller)
+	  support for the BCM2708. BSC is a Broadcom proprietary bus compatible
+	  with I2C/TWI/SMBus.
+
+config I2C_BCM2708_BAUDRATE
+	prompt "BCM2708 I2C baudrate"
+	depends on I2C_BCM2708
+	int
+	default 100000
+	help
+	  Set the I2C baudrate. This will alter the default value. A
+	  different baudrate can be set by using a module parameter as well. If
+	  no parameter is provided when loading, this is the value that will be
+	  used.
+
 config I2C_BCM_KONA
 	tristate "BCM Kona I2C adapter"
 	depends on ARCH_BCM_MOBILE
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_I2C_AT91)		+= i2c-at91.o
 obj-$(CONFIG_I2C_AU1550)	+= i2c-au1550.o
 obj-$(CONFIG_I2C_AXXIA)		+= i2c-axxia.o
 obj-$(CONFIG_I2C_BCM2835)	+= i2c-bcm2835.o
+obj-$(CONFIG_I2C_BCM2708)	+= i2c-bcm2708.o
 obj-$(CONFIG_I2C_BLACKFIN_TWI)	+= i2c-bfin-twi.o
 obj-$(CONFIG_I2C_CADENCE)	+= i2c-cadence.o
 obj-$(CONFIG_I2C_CBUS_GPIO)	+= i2c-cbus-gpio.o
--- /dev/null
+++ b/drivers/i2c/busses/i2c-bcm2708.c
@@ -0,0 +1,420 @@
+/*
+ * Driver for Broadcom BCM2708 BSC Controllers
+ *
+ * Copyright (C) 2012 Chris Boot & Frank Buss
+ *
+ * This driver is inspired by:
+ * i2c-ocores.c, by Peter Korsgaard <jacmet@sunsite.dk>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+/* BSC register offsets */
+#define BSC_C			0x00
+#define BSC_S			0x04
+#define BSC_DLEN		0x08
+#define BSC_A			0x0c
+#define BSC_FIFO		0x10
+#define BSC_DIV			0x14
+#define BSC_DEL			0x18
+#define BSC_CLKT		0x1c
+
+/* Bitfields in BSC_C */
+#define BSC_C_I2CEN		0x00008000
+#define BSC_C_INTR		0x00000400
+#define BSC_C_INTT		0x00000200
+#define BSC_C_INTD		0x00000100
+#define BSC_C_ST		0x00000080
+#define BSC_C_CLEAR_1		0x00000020
+#define BSC_C_CLEAR_2		0x00000010
+#define BSC_C_READ		0x00000001
+
+/* Bitfields in BSC_S */
+#define BSC_S_CLKT		0x00000200
+#define BSC_S_ERR		0x00000100
+#define BSC_S_RXF		0x00000080
+#define BSC_S_TXE		0x00000040
+#define BSC_S_RXD		0x00000020
+#define BSC_S_TXD		0x00000010
+#define BSC_S_RXR		0x00000008
+#define BSC_S_TXW		0x00000004
+#define BSC_S_DONE		0x00000002
+#define BSC_S_TA		0x00000001
+
+#define I2C_TIMEOUT_MS	150
+
+#define DRV_NAME	"bcm2708_i2c"
+
+static unsigned int baudrate = CONFIG_I2C_BCM2708_BAUDRATE;
+module_param(baudrate, uint, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+MODULE_PARM_DESC(baudrate, "The I2C baudrate");
+
+
+struct bcm2708_i2c {
+	struct i2c_adapter adapter;
+
+	spinlock_t lock;
+	void __iomem *base;
+	int irq;
+	struct clk *clk;
+
+	struct completion done;
+
+	struct i2c_msg *msg;
+	int pos;
+	int nmsgs;
+	bool error;
+};
+
+/*
+ * This function sets the ALT mode on the I2C pins so that we can use them with
+ * the BSC hardware.
+ *
+ * FIXME: This is a hack. Use pinmux / pinctrl.
+ */
+static void bcm2708_i2c_init_pinmode(int id)
+{
+#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
+#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
+
+	int pin;
+	u32 *gpio = ioremap(GPIO_BASE, SZ_16K);
+
+        BUG_ON(id != 0 && id != 1);
+	/* BSC0 is on GPIO 0 & 1, BSC1 is on GPIO 2 & 3 */
+	for (pin = id*2+0; pin <= id*2+1; pin++) {
+printk("bcm2708_i2c_init_pinmode(%d,%d)\n", id, pin);
+		INP_GPIO(pin);		/* set mode to GPIO input first */
+		SET_GPIO_ALT(pin, 0);	/* set mode to ALT 0 */
+	}
+
+	iounmap(gpio);
+
+#undef INP_GPIO
+#undef SET_GPIO_ALT
+}
+
+static inline u32 bcm2708_rd(struct bcm2708_i2c *bi, unsigned reg)
+{
+	return readl(bi->base + reg);
+}
+
+static inline void bcm2708_wr(struct bcm2708_i2c *bi, unsigned reg, u32 val)
+{
+	writel(val, bi->base + reg);
+}
+
+static inline void bcm2708_bsc_reset(struct bcm2708_i2c *bi)
+{
+	bcm2708_wr(bi, BSC_C, 0);
+	bcm2708_wr(bi, BSC_S, BSC_S_CLKT | BSC_S_ERR | BSC_S_DONE);
+}
+
+static inline void bcm2708_bsc_fifo_drain(struct bcm2708_i2c *bi)
+{
+	while ((bcm2708_rd(bi, BSC_S) & BSC_S_RXD) && (bi->pos < bi->msg->len))
+		bi->msg->buf[bi->pos++] = bcm2708_rd(bi, BSC_FIFO);
+}
+
+static inline void bcm2708_bsc_fifo_fill(struct bcm2708_i2c *bi)
+{
+	while ((bcm2708_rd(bi, BSC_S) & BSC_S_TXD) && (bi->pos < bi->msg->len))
+		bcm2708_wr(bi, BSC_FIFO, bi->msg->buf[bi->pos++]);
+}
+
+static inline void bcm2708_bsc_setup(struct bcm2708_i2c *bi)
+{
+	unsigned long bus_hz;
+	u32 cdiv;
+	u32 c = BSC_C_I2CEN | BSC_C_INTD | BSC_C_ST | BSC_C_CLEAR_1;
+
+	bus_hz = clk_get_rate(bi->clk);
+	cdiv = bus_hz / baudrate;
+	if (cdiv > 0xffff)
+		cdiv = 0xffff;
+
+	if (bi->msg->flags & I2C_M_RD)
+		c |= BSC_C_INTR | BSC_C_READ;
+	else
+		c |= BSC_C_INTT;
+
+	bcm2708_wr(bi, BSC_DIV, cdiv);
+	bcm2708_wr(bi, BSC_A, bi->msg->addr);
+	bcm2708_wr(bi, BSC_DLEN, bi->msg->len);
+	bcm2708_wr(bi, BSC_C, c);
+}
+
+static irqreturn_t bcm2708_i2c_interrupt(int irq, void *dev_id)
+{
+	struct bcm2708_i2c *bi = dev_id;
+	bool handled = true;
+	u32 s;
+
+	spin_lock(&bi->lock);
+
+	/* we may see camera interrupts on the "other" I2C channel
+           Just return if we've not sent anything */
+        if (!bi->nmsgs || !bi->msg )
+		goto early_exit;
+
+	s = bcm2708_rd(bi, BSC_S);
+
+	if (s & (BSC_S_CLKT | BSC_S_ERR)) {
+		bcm2708_bsc_reset(bi);
+		bi->error = true;
+
+		/* wake up our bh */
+		complete(&bi->done);
+	} else if (s & BSC_S_DONE) {
+		bi->nmsgs--;
+
+		if (bi->msg->flags & I2C_M_RD)
+			bcm2708_bsc_fifo_drain(bi);
+
+		bcm2708_bsc_reset(bi);
+
+		if (bi->nmsgs) {
+			/* advance to next message */
+			bi->msg++;
+			bi->pos = 0;
+			bcm2708_bsc_setup(bi);
+		} else {
+			/* wake up our bh */
+			complete(&bi->done);
+		}
+	} else if (s & BSC_S_TXW) {
+		bcm2708_bsc_fifo_fill(bi);
+	} else if (s & BSC_S_RXR) {
+		bcm2708_bsc_fifo_drain(bi);
+	} else {
+		handled = false;
+	}
+
+early_exit:
+	spin_unlock(&bi->lock);
+
+	return handled ? IRQ_HANDLED : IRQ_NONE;
+}
+
+static int bcm2708_i2c_master_xfer(struct i2c_adapter *adap,
+	struct i2c_msg *msgs, int num)
+{
+	struct bcm2708_i2c *bi = adap->algo_data;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&bi->lock, flags);
+
+	reinit_completion(&bi->done);
+	bi->msg = msgs;
+	bi->pos = 0;
+	bi->nmsgs = num;
+	bi->error = false;
+
+	bcm2708_bsc_setup(bi);
+
+	/* unlockig _after_ the setup to avoid races with the interrupt routine */
+	spin_unlock_irqrestore(&bi->lock, flags);
+
+	ret = wait_for_completion_timeout(&bi->done,
+			msecs_to_jiffies(I2C_TIMEOUT_MS));
+	if (ret == 0) {
+		dev_err(&adap->dev, "transfer timed out\n");
+		spin_lock_irqsave(&bi->lock, flags);
+		bcm2708_bsc_reset(bi);
+		spin_unlock_irqrestore(&bi->lock, flags);
+		return -ETIMEDOUT;
+	}
+
+	return bi->error ? -EIO : num;
+}
+
+static u32 bcm2708_i2c_functionality(struct i2c_adapter *adap)
+{
+	return I2C_FUNC_I2C | /*I2C_FUNC_10BIT_ADDR |*/ I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm bcm2708_i2c_algorithm = {
+	.master_xfer = bcm2708_i2c_master_xfer,
+	.functionality = bcm2708_i2c_functionality,
+};
+
+static int bcm2708_i2c_probe(struct platform_device *pdev)
+{
+	struct resource *regs;
+	int irq, err = -ENOMEM;
+	struct clk *clk;
+	struct bcm2708_i2c *bi;
+	struct i2c_adapter *adap;
+	unsigned long bus_hz;
+	u32 cdiv;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "could not get IO memory\n");
+		return -ENXIO;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "could not get IRQ\n");
+		return irq;
+	}
+
+	clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "could not find clk: %ld\n", PTR_ERR(clk));
+		return PTR_ERR(clk);
+	}
+
+	bcm2708_i2c_init_pinmode(pdev->id);
+
+	bi = kzalloc(sizeof(*bi), GFP_KERNEL);
+	if (!bi)
+		goto out_clk_put;
+
+	platform_set_drvdata(pdev, bi);
+
+	adap = &bi->adapter;
+	adap->class = I2C_CLASS_HWMON | I2C_CLASS_DDC;
+	adap->algo = &bcm2708_i2c_algorithm;
+	adap->algo_data = bi;
+	adap->dev.parent = &pdev->dev;
+	adap->nr = pdev->id;
+	strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
+
+	switch (pdev->id) {
+	case 0:
+		adap->class = I2C_CLASS_HWMON;
+		break;
+	case 1:
+		adap->class = I2C_CLASS_DDC;
+		break;
+	default:
+		dev_err(&pdev->dev, "can only bind to BSC 0 or 1\n");
+		err = -ENXIO;
+		goto out_free_bi;
+	}
+
+	spin_lock_init(&bi->lock);
+	init_completion(&bi->done);
+
+	bi->base = ioremap(regs->start, resource_size(regs));
+	if (!bi->base) {
+		dev_err(&pdev->dev, "could not remap memory\n");
+		goto out_free_bi;
+	}
+
+	bi->irq = irq;
+	bi->clk = clk;
+
+	err = request_irq(irq, bcm2708_i2c_interrupt, IRQF_SHARED,
+			dev_name(&pdev->dev), bi);
+	if (err) {
+		dev_err(&pdev->dev, "could not request IRQ: %d\n", err);
+		goto out_iounmap;
+	}
+
+	bcm2708_bsc_reset(bi);
+
+	err = i2c_add_numbered_adapter(adap);
+	if (err < 0) {
+		dev_err(&pdev->dev, "could not add I2C adapter: %d\n", err);
+		goto out_free_irq;
+	}
+
+	bus_hz = clk_get_rate(bi->clk);
+	cdiv = bus_hz / baudrate;
+	if (cdiv > 0xffff) {
+		cdiv = 0xffff;
+		baudrate = bus_hz / cdiv;
+	}
+
+	dev_info(&pdev->dev, "BSC%d Controller at 0x%08lx (irq %d) (baudrate %d)\n",
+		pdev->id, (unsigned long)regs->start, irq, baudrate);
+
+	return 0;
+
+out_free_irq:
+	free_irq(bi->irq, bi);
+out_iounmap:
+	iounmap(bi->base);
+out_free_bi:
+	kfree(bi);
+out_clk_put:
+	clk_put(clk);
+	return err;
+}
+
+static int bcm2708_i2c_remove(struct platform_device *pdev)
+{
+	struct bcm2708_i2c *bi = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	i2c_del_adapter(&bi->adapter);
+	free_irq(bi->irq, bi);
+	iounmap(bi->base);
+	clk_disable(bi->clk);
+	clk_put(bi->clk);
+	kfree(bi);
+
+	return 0;
+}
+
+static struct platform_driver bcm2708_i2c_driver = {
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= bcm2708_i2c_probe,
+	.remove		= bcm2708_i2c_remove,
+};
+
+// module_platform_driver(bcm2708_i2c_driver);
+
+
+static int __init bcm2708_i2c_init(void)
+{
+	return platform_driver_register(&bcm2708_i2c_driver);
+}
+
+static void __exit bcm2708_i2c_exit(void)
+{
+	platform_driver_unregister(&bcm2708_i2c_driver);
+}
+
+module_init(bcm2708_i2c_init);
+module_exit(bcm2708_i2c_exit);
+
+
+
+MODULE_DESCRIPTION("BSC controller driver for Broadcom BCM2708");
+MODULE_AUTHOR("Chris Boot <bootc@bootc.net>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -86,6 +86,14 @@ config SPI_BCM2835
 	  is for the regular SPI controller. Slave mode operation is not also
 	  not supported.
 
+config SPI_BCM2708
+	tristate "BCM2708 SPI controller driver (SPI0)"
+	depends on MACH_BCM2708
+	help
+	  This selects a driver for the Broadcom BCM2708 SPI master (SPI0). This
+	  driver is not compatible with the "Universal SPI Master" or the SPI slave
+	  device.
+
 config SPI_BFIN5XX
 	tristate "SPI controller driver for ADI Blackfin5xx"
 	depends on BLACKFIN && !BF60x
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_SPI_BCM63XX)		+= spi-bcm63x
 obj-$(CONFIG_SPI_BCM63XX_HSSPI)		+= spi-bcm63xx-hsspi.o
 obj-$(CONFIG_SPI_BFIN5XX)		+= spi-bfin5xx.o
 obj-$(CONFIG_SPI_ADI_V3)                += spi-adi-v3.o
+obj-$(CONFIG_SPI_BCM2708)		+= spi-bcm2708.o
 obj-$(CONFIG_SPI_BFIN_SPORT)		+= spi-bfin-sport.o
 obj-$(CONFIG_SPI_BITBANG)		+= spi-bitbang.o
 obj-$(CONFIG_SPI_BUTTERFLY)		+= spi-butterfly.o
--- /dev/null
+++ b/drivers/spi/spi-bcm2708.c
@@ -0,0 +1,626 @@
+/*
+ * Driver for Broadcom BCM2708 SPI Controllers
+ *
+ * Copyright (C) 2012 Chris Boot
+ *
+ * This driver is inspired by:
+ * spi-ath79.c, Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
+ * spi-atmel.c, Copyright (C) 2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/log2.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+/* SPI register offsets */
+#define SPI_CS			0x00
+#define SPI_FIFO		0x04
+#define SPI_CLK			0x08
+#define SPI_DLEN		0x0c
+#define SPI_LTOH		0x10
+#define SPI_DC			0x14
+
+/* Bitfields in CS */
+#define SPI_CS_LEN_LONG		0x02000000
+#define SPI_CS_DMA_LEN		0x01000000
+#define SPI_CS_CSPOL2		0x00800000
+#define SPI_CS_CSPOL1		0x00400000
+#define SPI_CS_CSPOL0		0x00200000
+#define SPI_CS_RXF		0x00100000
+#define SPI_CS_RXR		0x00080000
+#define SPI_CS_TXD		0x00040000
+#define SPI_CS_RXD		0x00020000
+#define SPI_CS_DONE		0x00010000
+#define SPI_CS_LEN		0x00002000
+#define SPI_CS_REN		0x00001000
+#define SPI_CS_ADCS		0x00000800
+#define SPI_CS_INTR		0x00000400
+#define SPI_CS_INTD		0x00000200
+#define SPI_CS_DMAEN		0x00000100
+#define SPI_CS_TA		0x00000080
+#define SPI_CS_CSPOL		0x00000040
+#define SPI_CS_CLEAR_RX		0x00000020
+#define SPI_CS_CLEAR_TX		0x00000010
+#define SPI_CS_CPOL		0x00000008
+#define SPI_CS_CPHA		0x00000004
+#define SPI_CS_CS_10		0x00000002
+#define SPI_CS_CS_01		0x00000001
+
+#define SPI_TIMEOUT_MS	150
+
+#define DRV_NAME	"bcm2708_spi"
+
+struct bcm2708_spi {
+	spinlock_t lock;
+	void __iomem *base;
+	int irq;
+	struct clk *clk;
+	bool stopping;
+
+	struct list_head queue;
+	struct workqueue_struct *workq;
+	struct work_struct work;
+	struct completion done;
+
+	const u8 *tx_buf;
+	u8 *rx_buf;
+	int len;
+};
+
+struct bcm2708_spi_state {
+	u32 cs;
+	u16 cdiv;
+};
+
+/*
+ * This function sets the ALT mode on the SPI pins so that we can use them with
+ * the SPI hardware.
+ *
+ * FIXME: This is a hack. Use pinmux / pinctrl.
+ */
+static void bcm2708_init_pinmode(void)
+{
+#define INP_GPIO(g) *(gpio+((g)/10)) &= ~(7<<(((g)%10)*3))
+#define SET_GPIO_ALT(g,a) *(gpio+(((g)/10))) |= (((a)<=3?(a)+4:(a)==4?3:2)<<(((g)%10)*3))
+
+	int pin;
+	u32 *gpio = ioremap(GPIO_BASE, SZ_16K);
+
+	/* SPI is on GPIO 7..11 */
+	for (pin = 7; pin <= 11; pin++) {
+		INP_GPIO(pin);		/* set mode to GPIO input first */
+		SET_GPIO_ALT(pin, 0);	/* set mode to ALT 0 */
+	}
+
+	iounmap(gpio);
+
+#undef INP_GPIO
+#undef SET_GPIO_ALT
+}
+
+static inline u32 bcm2708_rd(struct bcm2708_spi *bs, unsigned reg)
+{
+	return readl(bs->base + reg);
+}
+
+static inline void bcm2708_wr(struct bcm2708_spi *bs, unsigned reg, u32 val)
+{
+	writel(val, bs->base + reg);
+}
+
+static inline void bcm2708_rd_fifo(struct bcm2708_spi *bs, int len)
+{
+	u8 byte;
+
+	while (len--) {
+		byte = bcm2708_rd(bs, SPI_FIFO);
+		if (bs->rx_buf)
+			*bs->rx_buf++ = byte;
+	}
+}
+
+static inline void bcm2708_wr_fifo(struct bcm2708_spi *bs, int len)
+{
+	u8 byte;
+	u16 val;
+
+	if (len > bs->len)
+		len = bs->len;
+
+	if (unlikely(bcm2708_rd(bs, SPI_CS) & SPI_CS_LEN)) {
+		/* LoSSI mode */
+		if (unlikely(len % 2)) {
+			printk(KERN_ERR"bcm2708_wr_fifo: length must be even, skipping.\n");
+			bs->len = 0;
+			return;
+		}
+		while (len) {
+			if (bs->tx_buf) {
+				val = *(const u16 *)bs->tx_buf;
+				bs->tx_buf += 2;
+			} else
+				val = 0;
+			bcm2708_wr(bs, SPI_FIFO, val);
+			bs->len -= 2;
+			len -= 2;
+		}
+		return;
+	}
+
+	while (len--) {
+		byte = bs->tx_buf ? *bs->tx_buf++ : 0;
+		bcm2708_wr(bs, SPI_FIFO, byte);
+		bs->len--;
+	}
+}
+
+static irqreturn_t bcm2708_spi_interrupt(int irq, void *dev_id)
+{
+	struct spi_master *master = dev_id;
+	struct bcm2708_spi *bs = spi_master_get_devdata(master);
+	u32 cs;
+
+	spin_lock(&bs->lock);
+
+	cs = bcm2708_rd(bs, SPI_CS);
+
+	if (cs & SPI_CS_DONE) {
+		if (bs->len) { /* first interrupt in a transfer */
+			/* fill the TX fifo with up to 16 bytes */
+			bcm2708_wr_fifo(bs, 16);
+		} else { /* transfer complete */
+			/* disable interrupts */
+			cs &= ~(SPI_CS_INTR | SPI_CS_INTD);
+			bcm2708_wr(bs, SPI_CS, cs);
+
+			/* drain RX FIFO */
+			while (cs & SPI_CS_RXD) {
+				bcm2708_rd_fifo(bs, 1);
+				cs = bcm2708_rd(bs, SPI_CS);
+			}
+
+			/* wake up our bh */
+			complete(&bs->done);
+		}
+	} else if (cs & SPI_CS_RXR) {
+		/* read 12 bytes of data */
+		bcm2708_rd_fifo(bs, 12);
+
+		/* write up to 12 bytes */
+		bcm2708_wr_fifo(bs, 12);
+	}
+
+	spin_unlock(&bs->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int bcm2708_setup_state(struct spi_master *master,
+		struct device *dev, struct bcm2708_spi_state *state,
+		u32 hz, u8 csel, u8 mode, u8 bpw)
+{
+	struct bcm2708_spi *bs = spi_master_get_devdata(master);
+	int cdiv;
+	unsigned long bus_hz;
+	u32 cs = 0;
+
+	bus_hz = clk_get_rate(bs->clk);
+
+	if (hz >= bus_hz) {
+		cdiv = 2; /* bus_hz / 2 is as fast as we can go */
+	} else if (hz) {
+		cdiv = DIV_ROUND_UP(bus_hz, hz);
+
+		/* CDIV must be a power of 2, so round up */
+		cdiv = roundup_pow_of_two(cdiv);
+
+		if (cdiv > 65536) {
+			dev_dbg(dev,
+				"setup: %d Hz too slow, cdiv %u; min %ld Hz\n",
+				hz, cdiv, bus_hz / 65536);
+			return -EINVAL;
+		} else if (cdiv == 65536) {
+			cdiv = 0;
+		} else if (cdiv == 1) {
+			cdiv = 2; /* 1 gets rounded down to 0; == 65536 */
+		}
+	} else {
+		cdiv = 0;
+	}
+
+	switch (bpw) {
+	case 8:
+		break;
+	case 9:
+		/* Reading in LoSSI mode is a special case. See 'BCM2835 ARM Peripherals' datasheet */
+		cs |= SPI_CS_LEN;
+		break;
+	default:
+		dev_dbg(dev, "setup: invalid bits_per_word %u (must be 8 or 9)\n",
+			bpw);
+		return -EINVAL;
+	}
+
+	if (mode & SPI_CPOL)
+		cs |= SPI_CS_CPOL;
+	if (mode & SPI_CPHA)
+		cs |= SPI_CS_CPHA;
+
+	if (!(mode & SPI_NO_CS)) {
+		if (mode & SPI_CS_HIGH) {
+			cs |= SPI_CS_CSPOL;
+			cs |= SPI_CS_CSPOL0 << csel;
+		}
+
+		cs |= csel;
+	} else {
+		cs |= SPI_CS_CS_10 | SPI_CS_CS_01;
+	}
+
+	if (state) {
+		state->cs = cs;
+		state->cdiv = cdiv;
+		dev_dbg(dev, "setup: want %d Hz; "
+			"bus_hz=%lu / cdiv=%u == %lu Hz; "
+			"mode %u: cs 0x%08X\n",
+			hz, bus_hz, cdiv, bus_hz/cdiv, mode, cs);
+	}
+
+	return 0;
+}
+
+static int bcm2708_process_transfer(struct bcm2708_spi *bs,
+		struct spi_message *msg, struct spi_transfer *xfer)
+{
+	struct spi_device *spi = msg->spi;
+	struct bcm2708_spi_state state, *stp;
+	int ret;
+	u32 cs;
+
+	if (bs->stopping)
+		return -ESHUTDOWN;
+
+	if (xfer->bits_per_word || xfer->speed_hz) {
+		ret = bcm2708_setup_state(spi->master, &spi->dev, &state,
+			xfer->speed_hz ? xfer->speed_hz : spi->max_speed_hz,
+			spi->chip_select, spi->mode,
+			xfer->bits_per_word ? xfer->bits_per_word :
+				spi->bits_per_word);
+		if (ret)
+			return ret;
+
+		stp = &state;
+	} else {
+		stp = spi->controller_state;
+	}
+
+	reinit_completion(&bs->done);
+	bs->tx_buf = xfer->tx_buf;
+	bs->rx_buf = xfer->rx_buf;
+	bs->len = xfer->len;
+
+	cs = stp->cs | SPI_CS_INTR | SPI_CS_INTD | SPI_CS_TA;
+
+	bcm2708_wr(bs, SPI_CLK, stp->cdiv);
+	bcm2708_wr(bs, SPI_CS, cs);
+
+	ret = wait_for_completion_timeout(&bs->done,
+			msecs_to_jiffies(SPI_TIMEOUT_MS));
+	if (ret == 0) {
+		dev_err(&spi->dev, "transfer timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	if (xfer->delay_usecs)
+		udelay(xfer->delay_usecs);
+
+	if (list_is_last(&xfer->transfer_list, &msg->transfers) ||
+			xfer->cs_change) {
+		/* clear TA and interrupt flags */
+		bcm2708_wr(bs, SPI_CS, stp->cs);
+	}
+
+	msg->actual_length += (xfer->len - bs->len);
+
+	return 0;
+}
+
+static void bcm2708_work(struct work_struct *work)
+{
+	struct bcm2708_spi *bs = container_of(work, struct bcm2708_spi, work);
+	unsigned long flags;
+	struct spi_message *msg;
+	struct spi_transfer *xfer;
+	int status = 0;
+
+	spin_lock_irqsave(&bs->lock, flags);
+	while (!list_empty(&bs->queue)) {
+		msg = list_first_entry(&bs->queue, struct spi_message, queue);
+		list_del_init(&msg->queue);
+		spin_unlock_irqrestore(&bs->lock, flags);
+
+		list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+			status = bcm2708_process_transfer(bs, msg, xfer);
+			if (status)
+				break;
+		}
+
+		msg->status = status;
+		msg->complete(msg->context);
+
+		spin_lock_irqsave(&bs->lock, flags);
+	}
+	spin_unlock_irqrestore(&bs->lock, flags);
+}
+
+static int bcm2708_spi_setup(struct spi_device *spi)
+{
+	struct bcm2708_spi *bs = spi_master_get_devdata(spi->master);
+	struct bcm2708_spi_state *state;
+	int ret;
+
+	if (bs->stopping)
+		return -ESHUTDOWN;
+
+	if (!(spi->mode & SPI_NO_CS) &&
+			(spi->chip_select > spi->master->num_chipselect)) {
+		dev_dbg(&spi->dev,
+			"setup: invalid chipselect %u (%u defined)\n",
+			spi->chip_select, spi->master->num_chipselect);
+		return -EINVAL;
+	}
+
+	state = spi->controller_state;
+	if (!state) {
+		state = kzalloc(sizeof(*state), GFP_KERNEL);
+		if (!state)
+			return -ENOMEM;
+
+		spi->controller_state = state;
+	}
+
+	ret = bcm2708_setup_state(spi->master, &spi->dev, state,
+		spi->max_speed_hz, spi->chip_select, spi->mode,
+		spi->bits_per_word);
+	if (ret < 0) {
+		kfree(state);
+		spi->controller_state = NULL;
+                return ret;
+	}
+
+	dev_dbg(&spi->dev,
+		"setup: cd %d: %d Hz, bpw %u, mode 0x%x -> CS=%08x CDIV=%04x\n",
+		spi->chip_select, spi->max_speed_hz, spi->bits_per_word,
+		spi->mode, state->cs, state->cdiv);
+
+	return 0;
+}
+
+static int bcm2708_spi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+	struct bcm2708_spi *bs = spi_master_get_devdata(spi->master);
+	struct spi_transfer *xfer;
+	int ret;
+	unsigned long flags;
+
+	if (unlikely(list_empty(&msg->transfers)))
+		return -EINVAL;
+
+	if (bs->stopping)
+		return -ESHUTDOWN;
+
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		if (!(xfer->tx_buf || xfer->rx_buf) && xfer->len) {
+			dev_dbg(&spi->dev, "missing rx or tx buf\n");
+			return -EINVAL;
+		}
+
+		if (!xfer->bits_per_word || xfer->speed_hz)
+			continue;
+
+		ret = bcm2708_setup_state(spi->master, &spi->dev, NULL,
+			xfer->speed_hz ? xfer->speed_hz : spi->max_speed_hz,
+			spi->chip_select, spi->mode,
+			xfer->bits_per_word ? xfer->bits_per_word :
+				spi->bits_per_word);
+		if (ret)
+			return ret;
+	}
+
+	msg->status = -EINPROGRESS;
+	msg->actual_length = 0;
+
+	spin_lock_irqsave(&bs->lock, flags);
+	list_add_tail(&msg->queue, &bs->queue);
+	queue_work(bs->workq, &bs->work);
+	spin_unlock_irqrestore(&bs->lock, flags);
+
+	return 0;
+}
+
+static void bcm2708_spi_cleanup(struct spi_device *spi)
+{
+	if (spi->controller_state) {
+		kfree(spi->controller_state);
+		spi->controller_state = NULL;
+	}
+}
+
+static int bcm2708_spi_probe(struct platform_device *pdev)
+{
+	struct resource *regs;
+	int irq, err = -ENOMEM;
+	struct clk *clk;
+	struct spi_master *master;
+	struct bcm2708_spi *bs;
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!regs) {
+		dev_err(&pdev->dev, "could not get IO memory\n");
+		return -ENXIO;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(&pdev->dev, "could not get IRQ\n");
+		return irq;
+	}
+
+	clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "could not find clk: %ld\n", PTR_ERR(clk));
+		return PTR_ERR(clk);
+	}
+
+	bcm2708_init_pinmode();
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*bs));
+	if (!master) {
+		dev_err(&pdev->dev, "spi_alloc_master() failed\n");
+		goto out_clk_put;
+	}
+
+	/* the spi->mode bits understood by this driver: */
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_NO_CS;
+
+	master->bus_num = pdev->id;
+	master->num_chipselect = 3;
+	master->setup = bcm2708_spi_setup;
+	master->transfer = bcm2708_spi_transfer;
+	master->cleanup = bcm2708_spi_cleanup;
+	platform_set_drvdata(pdev, master);
+
+	bs = spi_master_get_devdata(master);
+
+	spin_lock_init(&bs->lock);
+	INIT_LIST_HEAD(&bs->queue);
+	init_completion(&bs->done);
+	INIT_WORK(&bs->work, bcm2708_work);
+
+	bs->base = ioremap(regs->start, resource_size(regs));
+	if (!bs->base) {
+		dev_err(&pdev->dev, "could not remap memory\n");
+		goto out_master_put;
+	}
+
+	bs->workq = create_singlethread_workqueue(dev_name(&pdev->dev));
+	if (!bs->workq) {
+		dev_err(&pdev->dev, "could not create workqueue\n");
+		goto out_iounmap;
+	}
+
+	bs->irq = irq;
+	bs->clk = clk;
+	bs->stopping = false;
+
+	err = request_irq(irq, bcm2708_spi_interrupt, 0, dev_name(&pdev->dev),
+			master);
+	if (err) {
+		dev_err(&pdev->dev, "could not request IRQ: %d\n", err);
+		goto out_workqueue;
+	}
+
+	/* initialise the hardware */
+	clk_enable(clk);
+	bcm2708_wr(bs, SPI_CS, SPI_CS_REN | SPI_CS_CLEAR_RX | SPI_CS_CLEAR_TX);
+
+	err = spi_register_master(master);
+	if (err) {
+		dev_err(&pdev->dev, "could not register SPI master: %d\n", err);
+		goto out_free_irq;
+	}
+
+	dev_info(&pdev->dev, "SPI Controller at 0x%08lx (irq %d)\n",
+		(unsigned long)regs->start, irq);
+
+	return 0;
+
+out_free_irq:
+	free_irq(bs->irq, master);
+out_workqueue:
+	destroy_workqueue(bs->workq);
+out_iounmap:
+	iounmap(bs->base);
+out_master_put:
+	spi_master_put(master);
+out_clk_put:
+	clk_put(clk);
+	return err;
+}
+
+static int bcm2708_spi_remove(struct platform_device *pdev)
+{
+	struct spi_master *master = platform_get_drvdata(pdev);
+	struct bcm2708_spi *bs = spi_master_get_devdata(master);
+
+	/* reset the hardware and block queue progress */
+	spin_lock_irq(&bs->lock);
+	bs->stopping = true;
+	bcm2708_wr(bs, SPI_CS, SPI_CS_CLEAR_RX | SPI_CS_CLEAR_TX);
+	spin_unlock_irq(&bs->lock);
+
+	flush_work(&bs->work);
+
+	clk_disable(bs->clk);
+	clk_put(bs->clk);
+	free_irq(bs->irq, master);
+	iounmap(bs->base);
+
+	spi_unregister_master(master);
+
+	return 0;
+}
+
+static struct platform_driver bcm2708_spi_driver = {
+	.driver		= {
+		.name	= DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe		= bcm2708_spi_probe,
+	.remove		= bcm2708_spi_remove,
+};
+
+
+static int __init bcm2708_spi_init(void)
+{
+	return platform_driver_probe(&bcm2708_spi_driver, bcm2708_spi_probe);
+}
+module_init(bcm2708_spi_init);
+
+static void __exit bcm2708_spi_exit(void)
+{
+	platform_driver_unregister(&bcm2708_spi_driver);
+}
+module_exit(bcm2708_spi_exit);
+
+
+//module_platform_driver(bcm2708_spi_driver);
+
+MODULE_DESCRIPTION("SPI controller driver for Broadcom BCM2708");
+MODULE_AUTHOR("Chris Boot <bootc@bootc.net>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);