i2c: move busses to drivers/i2c/busses

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

1 files changed, 520 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
new file mode 100644
index 0000000000..cc64d943c1
--- /dev/null
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -0,0 +1,520 @@
+/*
+ * Copyright (C) 2002 Motorola GSG-China
+ *               2009 Marc Kleine-Budde, Pengutronix
+ *
+ * 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.
+ *
+ * Author:
+ *	Darius Augulis, Teltonika Inc.
+ *
+ * Desc.:
+ *  Implementation of I2C Adapter/Algorithm Driver
+ *  for I2C Bus integrated in Freescale i.MX/MXC processors
+ *
+ * Derived from Motorola GSG China I2C example driver
+ *
+ * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
+ * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
+ * Copyright (C) 2007 RightHand Technologies, Inc.
+ * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
+ *
+ */
+
+#include <clock.h>
+#include <common.h>
+#include <driver.h>
+#include <gpio.h>
+#include <init.h>
+#include <malloc.h>
+#include <types.h>
+#include <xfuncs.h>
+
+#include <linux/err.h>
+
+#include <asm/io.h>
+#include <i2c/i2c.h>
+#include <mach/generic.h>
+#include <mach/clock.h>
+
+/* This will be the driver name */
+#define DRIVER_NAME "i2c-imx"
+
+/* Default value */
+#define IMX_I2C_BIT_RATE	100000	/* 100kHz */
+
+/* IMX I2C registers */
+#define IMX_I2C_IADR	0x00	/* i2c slave address */
+#define IMX_I2C_IFDR	0x04	/* i2c frequency divider */
+#define IMX_I2C_I2CR	0x08	/* i2c control */
+#define IMX_I2C_I2SR	0x0C	/* i2c status */
+#define IMX_I2C_I2DR	0x10	/* i2c transfer data */
+
+/* Bits of IMX I2C registers */
+#define I2SR_RXAK	0x01
+#define I2SR_IIF	0x02
+#define I2SR_SRW	0x04
+#define I2SR_IAL	0x10
+#define I2SR_IBB	0x20
+#define I2SR_IAAS	0x40
+#define I2SR_ICF	0x80
+#define I2CR_RSTA	0x04
+#define I2CR_TXAK	0x08
+#define I2CR_MTX	0x10
+#define I2CR_MSTA	0x20
+#define I2CR_IIEN	0x40
+#define I2CR_IEN	0x80
+
+/*
+ * sorted list of clock divider, register value pairs
+ * taken from table 26-5, p.26-9, Freescale i.MX
+ * Integrated Portable System Processor Reference Manual
+ * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
+ *
+ * Duplicated divider values removed from list
+ */
+static u16 i2c_clk_div[50][2] = {
+	{ 22,	0x20 }, { 24,	0x21 }, { 26,	0x22 }, { 28,	0x23 },
+	{ 30,	0x00 },	{ 32,	0x24 }, { 36,	0x25 }, { 40,	0x26 },
+	{ 42,	0x03 }, { 44,	0x27 },	{ 48,	0x28 }, { 52,	0x05 },
+	{ 56,	0x29 }, { 60,	0x06 }, { 64,	0x2A },	{ 72,	0x2B },
+	{ 80,	0x2C }, { 88,	0x09 }, { 96,	0x2D }, { 104,	0x0A },
+	{ 112,	0x2E }, { 128,	0x2F }, { 144,	0x0C }, { 160,	0x30 },
+	{ 192,	0x31 },	{ 224,	0x32 }, { 240,	0x0F }, { 256,	0x33 },
+	{ 288,	0x10 }, { 320,	0x34 },	{ 384,	0x35 }, { 448,	0x36 },
+	{ 480,	0x13 }, { 512,	0x37 }, { 576,	0x14 },	{ 640,	0x38 },
+	{ 768,	0x39 }, { 896,	0x3A }, { 960,	0x17 }, { 1024,	0x3B },
+	{ 1152,	0x18 }, { 1280,	0x3C }, { 1536,	0x3D }, { 1792,	0x3E },
+	{ 1920,	0x1B },	{ 2048,	0x3F }, { 2304,	0x1C }, { 2560,	0x1D },
+	{ 3072,	0x1E }, { 3840,	0x1F }
+};
+
+struct imx_i2c_struct {
+	struct i2c_adapter	adapter;
+	unsigned int 		disable_delay;
+	int			stopped;
+	unsigned int		ifdr;	/* IMX_I2C_IFDR */
+};
+#define to_imx_i2c_struct(a)	container_of(a, struct imx_i2c_struct, adapter)
+
+#ifdef CONFIG_I2C_DEBUG
+static void i2c_imx_dump_reg(struct i2c_adapter *adapter)
+{
+	unsigned long base = adapter->dev->map_base;
+	u32 reg_cr, reg_sr;
+
+	reg_cr = readb(base + IMX_I2C_I2CR);
+	reg_sr = readb(base + IMX_I2C_I2SR);
+
+	dev_dbg(adapter->dev, "CONTROL:\t"
+		"IEN =%d, IIEN=%d, MSTA=%d, MTX =%d, TXAK=%d, RSTA=%d\n",
+		(reg_cr & I2CR_IEN  ? 1 : 0), (reg_cr & I2CR_IIEN ? 1 : 0),
+		(reg_cr & I2CR_MSTA ? 1 : 0), (reg_cr & I2CR_MTX  ? 1 : 0),
+		(reg_cr & I2CR_TXAK ? 1 : 0), (reg_cr & I2CR_RSTA ? 1 : 0));
+
+	dev_dbg(adapter->dev, "STATUS:\t"
+		"ICF =%d, IAAS=%d, IB  =%d, IAL =%d, SRW =%d, IIF =%d, RXAK=%d\n",
+		(reg_sr & I2SR_ICF  ? 1 : 0), (reg_sr & I2SR_IAAS ? 1 : 0),
+		(reg_sr & I2SR_IBB  ? 1 : 0), (reg_sr & I2SR_IAL  ? 1 : 0),
+		(reg_sr & I2SR_SRW  ? 1 : 0), (reg_sr & I2SR_IIF  ? 1 : 0),
+		(reg_sr & I2SR_RXAK ? 1 : 0));
+}
+#else
+static inline void i2c_imx_dump_reg(struct i2c_adapter *adapter)
+{
+	return;
+}
+#endif
+
+static int i2c_imx_bus_busy(struct i2c_adapter *adapter, int for_busy)
+{
+	unsigned long base = adapter->dev->map_base;
+	uint64_t start;
+	unsigned int temp;
+
+	start = get_time_ns();
+	while (1) {
+		temp = readb(base + IMX_I2C_I2SR);
+		if (for_busy && (temp & I2SR_IBB))
+			break;
+		if (!for_busy && !(temp & I2SR_IBB))
+			break;
+		if (is_timeout(start, MSECOND)) {
+			dev_err(adapter->dev,
+				 "<%s> timeout waiting for I2C bus %s\n",
+				 __func__,for_busy ? "busy" : "not busy");
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int i2c_imx_trx_complete(struct i2c_adapter *adapter)
+{
+	unsigned long base = adapter->dev->map_base;
+	uint64_t start;
+
+	start = get_time_ns();
+	while (1) {
+		unsigned int reg = readb(base + IMX_I2C_I2SR);
+		if (reg & I2SR_ICF)
+			break;
+
+		if (is_timeout(start, 100 * MSECOND)) {
+			dev_err(adapter->dev, "<%s> TXR timeout\n", __func__);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int i2c_imx_wait_iif(struct i2c_adapter *adapter)
+{
+	unsigned long base = adapter->dev->map_base;
+	uint64_t start;
+
+	start = get_time_ns();
+	while (1) {
+		unsigned int reg = readb(base + IMX_I2C_I2SR);
+		if (reg & I2SR_IIF)
+			break;
+
+		if (is_timeout(start, 100 * MSECOND)) {
+			dev_err(adapter->dev, "<%s> IIF timeout\n", __func__);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int i2c_imx_acked(struct i2c_adapter *adapter)
+{
+	unsigned long base = adapter->dev->map_base;
+	uint64_t start;
+
+	start = get_time_ns();
+	while (1) {
+		unsigned int reg = readb(base + IMX_I2C_I2SR);
+		if (!(reg & I2SR_RXAK))
+			break;
+
+		if (is_timeout(start, MSECOND)) {
+			dev_dbg(adapter->dev, "<%s> No ACK\n", __func__);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int i2c_imx_start(struct i2c_adapter *adapter)
+{
+	struct imx_i2c_struct *i2c_imx = to_imx_i2c_struct(adapter);
+	unsigned long base = adapter->dev->map_base;
+	unsigned int temp = 0;
+	int result;
+
+	writeb(i2c_imx->ifdr, base + IMX_I2C_IFDR);
+	/* Enable I2C controller */
+	writeb(0, base + IMX_I2C_I2SR);
+	writeb(I2CR_IEN, base + IMX_I2C_I2CR);
+
+	/* Wait controller to be stable */
+	udelay(100);
+
+	/* Start I2C transaction */
+	temp = readb(base + IMX_I2C_I2CR);
+	temp |= I2CR_MSTA;
+	writeb(temp, base + IMX_I2C_I2CR);
+
+	result = i2c_imx_bus_busy(adapter, 1);
+	if (result)
+		return result;
+
+	i2c_imx->stopped = 0;
+
+	temp |= I2CR_MTX | I2CR_TXAK;
+	writeb(temp, base + IMX_I2C_I2CR);
+
+	return result;
+}
+
+static void i2c_imx_stop(struct i2c_adapter *adapter)
+{
+	struct imx_i2c_struct *i2c_imx = to_imx_i2c_struct(adapter);
+	unsigned long base = adapter->dev->map_base;
+	unsigned int temp = 0;
+
+	if (!i2c_imx->stopped) {
+		/* Stop I2C transaction */
+		temp = readb(base + IMX_I2C_I2CR);
+		temp &= ~(I2CR_MSTA | I2CR_MTX);
+		writeb(temp, base + IMX_I2C_I2CR);
+		i2c_imx->stopped = 1;
+	}
+	if (cpu_is_mx1()) {
+		/*
+		 * This delay caused by an i.MXL hardware bug.
+		 * If no (or too short) delay, no "STOP" bit will be generated.
+		 */
+		udelay(i2c_imx->disable_delay);
+	}
+
+	if (!i2c_imx->stopped)
+		i2c_imx_bus_busy(adapter, 0);
+
+	/* Disable I2C controller */
+	writeb(0, base + IMX_I2C_I2CR);
+}
+
+static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
+			    unsigned int rate)
+{
+	unsigned int i2c_clk_rate;
+	unsigned int div;
+	int i;
+
+	/* Divider value calculation */
+	i2c_clk_rate = imx_get_i2cclk();
+	div = (i2c_clk_rate + rate - 1) / rate;
+	if (div < i2c_clk_div[0][0])
+		i = 0;
+	else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
+		i = ARRAY_SIZE(i2c_clk_div) - 1;
+	else
+		for (i = 0; i2c_clk_div[i][0] < div; i++)
+			;
+
+	/* Store divider value */
+	i2c_imx->ifdr = i2c_clk_div[i][1];
+
+	/*
+	 * There dummy delay is calculated.
+	 * It should be about one I2C clock period long.
+	 * This delay is used in I2C bus disable function
+	 * to fix chip hardware bug.
+	 */
+	i2c_imx->disable_delay =
+		(500000U * i2c_clk_div[i][0] + (i2c_clk_rate / 2) - 1) /
+		(i2c_clk_rate / 2);
+
+	dev_dbg(i2c_imx->adapter.dev, "<%s> I2C_CLK=%d, REQ DIV=%d\n",
+		__func__, i2c_clk_rate, div);
+	dev_dbg(i2c_imx->adapter.dev, "<%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
+		__func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
+}
+
+static int i2c_imx_write(struct i2c_adapter *adapter, struct i2c_msg *msgs)
+{
+	unsigned long base = adapter->dev->map_base;
+	int i, result;
+
+	dev_dbg(adapter->dev,
+		"<%s> write slave address: addr=0x%02x\n",
+		__func__, msgs->addr << 1);
+
+	/* write slave address */
+	writeb(msgs->addr << 1, base + IMX_I2C_I2DR);
+
+	result = i2c_imx_trx_complete(adapter);
+	if (result)
+		return result;
+	result = i2c_imx_acked(adapter);
+	if (result)
+		return result;
+
+	/* write data */
+	for (i = 0; i < msgs->len; i++) {
+		dev_dbg(adapter->dev,
+			"<%s> write byte: B%d=0x%02X\n",
+			__func__, i, msgs->buf[i]);
+		writeb(msgs->buf[i], base + IMX_I2C_I2DR);
+
+		result = i2c_imx_trx_complete(adapter);
+		if (result)
+			return result;
+		result = i2c_imx_acked(adapter);
+		if (result)
+			return result;
+	}
+	return 0;
+}
+
+static int i2c_imx_read(struct i2c_adapter *adapter, struct i2c_msg *msgs)
+{
+	struct imx_i2c_struct *i2c_imx = to_imx_i2c_struct(adapter);
+	unsigned long base = adapter->dev->map_base;
+	int i, result;
+	unsigned int temp;
+
+	dev_dbg(adapter->dev,
+		"<%s> write slave address: addr=0x%02x\n",
+		__func__, (msgs->addr << 1) | 0x01);
+
+	/* clear IIF */
+	writeb(0x0, base + IMX_I2C_I2SR);
+
+	/* write slave address */
+	writeb((msgs->addr << 1) | 0x01, base + IMX_I2C_I2DR);
+
+	result = i2c_imx_trx_complete(adapter);
+	if (result)
+		return result;
+	result = i2c_imx_acked(adapter);
+	if (result)
+		return result;
+
+	result = i2c_imx_wait_iif(adapter);
+	if (result)
+		return result;
+
+	/* setup bus to read data */
+	temp = readb(base + IMX_I2C_I2CR);
+	temp &= ~I2CR_MTX;
+	if (msgs->len - 1)
+		temp &= ~I2CR_TXAK;
+	writeb(temp, base + IMX_I2C_I2CR);
+
+	readb(base + IMX_I2C_I2DR);	/* dummy read */
+
+	/* read data */
+	for (i = 0; i < msgs->len; i++) {
+		result = i2c_imx_trx_complete(adapter);
+		if (result)
+			return result;
+
+		if (i == (msgs->len - 1)) {
+			/*
+			 * It must generate STOP before read I2DR to prevent
+			 * controller from generating another clock cycle
+			 */
+			temp = readb(base + IMX_I2C_I2CR);
+			temp &= ~(I2CR_MSTA | I2CR_MTX);
+			writeb(temp, base + IMX_I2C_I2CR);
+
+			/*
+			 * adding this delay helps on low bitrates
+			 */
+			udelay(i2c_imx->disable_delay);
+
+			i2c_imx_bus_busy(adapter, 0);
+			i2c_imx->stopped = 1;
+		} else if (i == (msgs->len - 2)) {
+			temp = readb(base + IMX_I2C_I2CR);
+			temp |= I2CR_TXAK;
+			writeb(temp, base + IMX_I2C_I2CR);
+		}
+		msgs->buf[i] = readb(base + IMX_I2C_I2DR);
+
+		dev_dbg(adapter->dev, "<%s> read byte: B%d=0x%02X\n",
+			__func__, i, msgs->buf[i]);
+	}
+	return 0;
+}
+
+static int i2c_imx_xfer(struct i2c_adapter *adapter,
+			struct i2c_msg *msgs, int num)
+{
+	unsigned long base = adapter->dev->map_base;
+	unsigned int i, temp;
+	int result;
+
+	/* Start I2C transfer */
+	result = i2c_imx_start(adapter);
+	if (result)
+		goto fail0;
+
+	/* read/write data */
+	for (i = 0; i < num; i++) {
+		if (i) {
+			temp = readb(base + IMX_I2C_I2CR);
+			temp |= I2CR_RSTA;
+			writeb(temp, base + IMX_I2C_I2CR);
+
+			result = i2c_imx_bus_busy(adapter, 1);
+			if (result)
+				goto fail0;
+		}
+		i2c_imx_dump_reg(adapter);
+
+		/* write/read data */
+		if (msgs[i].flags & I2C_M_RD)
+			result = i2c_imx_read(adapter, &msgs[i]);
+		else
+			result = i2c_imx_write(adapter, &msgs[i]);
+		if (result)
+			goto fail0;
+	}
+
+fail0:
+	/* Stop I2C transfer */
+	i2c_imx_stop(adapter);
+
+	return (result < 0) ? result : num;
+}
+
+static int __init i2c_imx_probe(struct device_d *pdev)
+{
+	struct imx_i2c_struct *i2c_imx;
+	struct i2c_platform_data *pdata;
+	unsigned long base = pdev->map_base;
+	int ret;
+
+	pdata = pdev->platform_data;
+
+	i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
+
+	/* Setup i2c_imx driver structure */
+	i2c_imx->adapter.master_xfer = i2c_imx_xfer;
+	i2c_imx->adapter.nr = pdev->id;
+	i2c_imx->adapter.dev = pdev;
+
+	/* Set up clock divider */
+	if (pdata && pdata->bitrate)
+		i2c_imx_set_clk(i2c_imx, pdata->bitrate);
+	else
+		i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
+
+	/* Set up chip registers to defaults */
+	writeb(0, base + IMX_I2C_I2CR);
+	writeb(0, base + IMX_I2C_I2SR);
+
+	/* Add I2C adapter */
+	ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
+	if (ret < 0) {
+		dev_err(pdev, "registration failed\n");
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	kfree(i2c_imx);
+	return ret;
+}
+
+static struct driver_d i2c_imx_driver = {
+	.probe	= i2c_imx_probe,
+	.name	= DRIVER_NAME,
+};
+
+static int __init i2c_adap_imx_init(void)
+{
+	return register_driver(&i2c_imx_driver);
+}
+device_initcall(i2c_adap_imx_init);