Index: linux-3.18.9/drivers/i2c/busses/Kconfig
===================================================================
--- linux-3.18.9.orig/drivers/i2c/busses/Kconfig 2015-03-23 15:00:11.730403938 +0800
+++ linux-3.18.9/drivers/i2c/busses/Kconfig 2015-03-23 15:00:11.982403926 +0800
@@ -714,6 +714,10 @@
tristate "Ralink I2C Controller"
select OF_I2C
+config I2C_MT7621
+ tristate "MT7621 I2C Controller"
+ select OF_I2C
+
config HAVE_S3C2410_I2C
bool
help
Index: linux-3.18.9/drivers/i2c/busses/Makefile
===================================================================
--- linux-3.18.9.orig/drivers/i2c/busses/Makefile 2015-03-23 15:00:11.730403938 +0800
+++ linux-3.18.9/drivers/i2c/busses/Makefile 2015-03-23 15:00:11.982403926 +0800
@@ -67,6 +67,7 @@
obj-$(CONFIG_I2C_PXA) += i2c-pxa.o
obj-$(CONFIG_I2C_PXA_PCI) += i2c-pxa-pci.o
obj-$(CONFIG_I2C_RALINK) += i2c-ralink.o
+obj-$(CONFIG_I2C_MT7621) += i2c-mt7621.o
obj-$(CONFIG_I2C_QUP) += i2c-qup.o
obj-$(CONFIG_I2C_RIIC) += i2c-riic.o
obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o
Index: linux-3.18.9/drivers/i2c/busses/i2c-mt7621.c
===================================================================
--- /dev/null 1970-01-01 00:00:00.000000000 +0000
+++ linux-3.18.9/drivers/i2c/busses/i2c-mt7621.c 2015-03-23 16:31:42.684747034 +0800
@@ -0,0 +1,303 @@
+/*
+ * drivers/i2c/busses/i2c-mt7621.c
+ *
+ * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
+ *
+ * Improve driver for i2cdetect from i2c-tools to detect i2c devices on the bus.
+ * (C) 2014 Sittisak <sittisaks@hotmail.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/reset.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/err.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define REG_CONFIG_REG 0x00
+#define REG_CLKDIV_REG 0x04
+#define REG_DEVADDR_REG 0x08
+#define REG_ADDR_REG 0x0C
+#define REG_DATAOUT_REG 0x10
+#define REG_DATAIN_REG 0x14
+#define REG_STATUS_REG 0x18
+#define REG_STARTXFR_REG 0x1C
+#define REG_BYTECNT_REG 0x20
+#define REG_SM0_IS_AUTOMODE 0x28
+#define REG_SM0CTL0 0x40
+
+
+#define I2C_STARTERR 0x10
+#define I2C_ACKERR 0x08
+#define I2C_DATARDY 0x04
+#define I2C_SDOEMPTY 0x02
+#define I2C_BUSY 0x01
+
+/* I2C_CFG register bit field */
+#define I2C_CFG_ADDRLEN_8 (7<<5) /* 8 bits */
+#define I2C_CFG_DEVADLEN_7 (6<<2)
+#define I2C_CFG_ADDRDIS BIT(1)
+#define I2C_CFG_DEVADDIS BIT(0)
+
+#define I2C_CFG_DEFAULT (I2C_CFG_ADDRLEN_8 | \
+ I2C_CFG_DEVADLEN_7 | \
+ I2C_CFG_ADDRDIS)
+
+#define I2C_RETRY 0x1000
+
+#define CLKDIV_VALUE 333
+#define i2c_busy_loop (CLKDIV_VALUE*30)
+
+#define READ_CMD 0x01
+#define WRITE_CMD 0x00
+#define READ_BLOCK 16
+
+#define SM0_ODRAIN BIT(31)
+#define SM0_VSYNC_MODE BIT(28)
+#define SM0_CLK_DIV (CLKDIV_VALUE << 16)
+#define SM0_WAIT_LEVEL BIT(6)
+#define SM0_EN BIT(1)
+
+#define SM0_CFG_DEFUALT (SM0_ODRAIN | SM0_VSYNC_MODE | \
+ SM0_CLK_DIV | SM0_WAIT_LEVEL | \
+ SM0_EN)
+/***********************************************************/
+
+static void __iomem *membase;
+static struct i2c_adapter *adapter;
+
+static void rt_i2c_w32(u32 val, unsigned reg)
+{
+ iowrite32(val, membase + reg);
+}
+
+static u32 rt_i2c_r32(unsigned reg)
+{
+ return ioread32(membase + reg);
+}
+
+static void mt7621_i2c_reset(struct i2c_adapter *a)
+{
+ device_reset(a->dev.parent);
+}
+static void mt7621_i2c_enable(struct i2c_msg *msg)
+{
+ rt_i2c_w32(msg->addr,REG_DEVADDR_REG);
+ rt_i2c_w32(0,REG_ADDR_REG);
+}
+
+static void i2c_master_init(struct i2c_adapter *a)
+{
+ mt7621_i2c_reset(a);
+ rt_i2c_w32(I2C_CFG_DEFAULT,REG_CONFIG_REG);
+ rt_i2c_w32(SM0_CFG_DEFUALT,REG_SM0CTL0);
+ rt_i2c_w32(1,REG_SM0_IS_AUTOMODE);//auto mode
+}
+
+
+static inline int rt_i2c_wait_rx_done(void)
+{
+ int i=0;
+ while((!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY)) && (i<i2c_busy_loop))
+ i++;
+ if(i>=i2c_busy_loop){
+ pr_err("err,wait for idle timeout");
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static inline int rt_i2c_wait_idle(void)
+{
+ int i=0;
+ while((rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY) && (i<i2c_busy_loop))
+ i++;
+ if(i>=i2c_busy_loop){
+ pr_err("err,wait for idle timeout");
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static inline int rt_i2c_wait_tx_done(void)
+{
+ int i=0;
+ while((!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY)) && (i<i2c_busy_loop))
+ i++;
+ if(i>=i2c_busy_loop){
+ pr_err("err,wait for idle timeout");
+ return -ETIMEDOUT;
+ }
+ return 0;
+}
+
+static int rt_i2c_handle_msg(struct i2c_adapter *a, struct i2c_msg* msg)
+{
+ int i = 0, j = 0, pos = 0;
+ int nblock = msg->len / READ_BLOCK;
+ int rem = msg->len % READ_BLOCK;
+
+ if (msg->flags & I2C_M_TEN) {
+ printk("10 bits addr not supported\n");
+ return -EINVAL;
+ }
+
+ if (msg->flags & I2C_M_RD) {
+ for (i = 0; i < nblock; i++) {
+ if (rt_i2c_wait_idle())
+ goto err_timeout;
+ rt_i2c_w32(READ_BLOCK - 1, REG_BYTECNT_REG);
+ rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
+ for (j = 0; j < READ_BLOCK; j++) {
+ if (rt_i2c_wait_rx_done())
+ goto err_timeout;
+ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
+ }
+ }
+
+ if (rt_i2c_wait_idle())
+ goto err_timeout;
+ rt_i2c_w32(rem - 1, REG_BYTECNT_REG);
+ rt_i2c_w32(READ_CMD, REG_STARTXFR_REG);
+
+ for (i = 0; i < rem; i++) {
+ if (rt_i2c_wait_rx_done())
+ goto err_timeout;
+ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
+ }
+ } else {
+ if (rt_i2c_wait_idle())
+ goto err_timeout;
+ rt_i2c_w32(msg->len - 1, REG_BYTECNT_REG);
+ for (i = 0; i < msg->len; i++) {
+ rt_i2c_w32(msg->buf[i], REG_DATAOUT_REG);
+ if(i == 0)
+ rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
+
+ if (rt_i2c_wait_tx_done())
+ goto err_timeout;
+ }
+ }
+
+ return 0;
+err_timeout:
+ return -ETIMEDOUT;
+}
+
+static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
+{
+ int i = 0;
+ int ret = 0;
+ i2c_master_init(a);
+ mt7621_i2c_enable(m);
+
+ for (i = 0; i != n && ret==0; i++) {
+ ret = rt_i2c_handle_msg(a, &m[i]);
+ if (ret)
+ return ret;
+ }
+ return i;
+}
+
+static u32 rt_i2c_func(struct i2c_adapter *a)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm rt_i2c_algo = {
+ .master_xfer = rt_i2c_master_xfer,
+ .functionality = rt_i2c_func,
+};
+
+static int rt_i2c_probe(struct platform_device *pdev)
+{
+ struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ int ret;
+
+ adapter = devm_kzalloc(&pdev->dev,sizeof(struct i2c_adapter), GFP_KERNEL);
+ if (!adapter) {
+ dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
+ return -ENOMEM;
+ }
+ membase = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(membase))
+ return PTR_ERR(membase);
+
+ strlcpy(adapter->name, dev_name(&pdev->dev), sizeof(adapter->name));
+
+ adapter->owner = THIS_MODULE;
+ adapter->nr = pdev->id;
+ adapter->timeout = HZ;
+ adapter->algo = &rt_i2c_algo;
+ adapter->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+ adapter->dev.parent = &pdev->dev;
+ adapter->dev.of_node = pdev->dev.of_node;
+
+ platform_set_drvdata(pdev, adapter);
+
+ ret = i2c_add_numbered_adapter(adapter);
+ if (ret)
+ return ret;
+
+ dev_info(&pdev->dev,"loaded");
+
+ return 0;
+}
+
+static int rt_i2c_remove(struct platform_device *pdev)
+{
+ platform_set_drvdata(pdev, NULL);
+ return 0;
+}
+
+static const struct of_device_id i2c_rt_dt_ids[] = {
+ { .compatible = "ralink,i2c-mt7621", },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
+
+static struct platform_driver rt_i2c_driver = {
+ .probe = rt_i2c_probe,
+ .remove = rt_i2c_remove,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "i2c-mt7621",
+ .of_match_table = i2c_rt_dt_ids,
+ },
+};
+
+static int __init i2c_rt_init (void)
+{
+ return platform_driver_register(&rt_i2c_driver);
+}
+
+static void __exit i2c_rt_exit (void)
+{
+ platform_driver_unregister(&rt_i2c_driver);
+}
+module_init (i2c_rt_init);
+module_exit (i2c_rt_exit);
+
+MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
+MODULE_DESCRIPTION("MT7621 I2c host driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:MT7621-I2C");