--- /dev/null
+From 4596818bca07e0928168970839e08875cf51b4cc Mon Sep 17 00:00:00 2001
+From: John Crispin <blogic@openwrt.org>
+Date: Mon, 29 Apr 2013 14:40:43 +0200
+Subject: [PATCH 26/33] i2c: MIPS: adds ralink I2C driver
+
+Signed-off-by: John Crispin <blogic@openwrt.org>
+---
+ .../devicetree/bindings/i2c/i2c-ralink.txt | 27 ++
+ drivers/i2c/busses/Kconfig | 4 +
+ drivers/i2c/busses/Makefile | 1 +
+ drivers/i2c/busses/i2c-ralink.c | 274 ++++++++++++++++++++
+ 4 files changed, 306 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/i2c/i2c-ralink.txt
+ create mode 100644 drivers/i2c/busses/i2c-ralink.c
+
+diff --git a/Documentation/devicetree/bindings/i2c/i2c-ralink.txt b/Documentation/devicetree/bindings/i2c/i2c-ralink.txt
+new file mode 100644
+index 0000000..8fa8ac3
+--- /dev/null
++++ b/Documentation/devicetree/bindings/i2c/i2c-ralink.txt
+@@ -0,0 +1,27 @@
++I2C for Ralink platforms
++
++Required properties :
++- compatible : Must be "link,rt3052-i2c"
++- reg: physical base address of the controller and length of memory mapped
++ region.
++- #address-cells = <1>;
++- #size-cells = <0>;
++
++Optional properties:
++- Child nodes conforming to i2c bus binding
++
++Example :
++
++palmbus@10000000 {
++ i2c@900 {
++ compatible = "link,rt3052-i2c";
++ reg = <0x900 0x100>;
++ #address-cells = <1>;
++ #size-cells = <0>;
++
++ hwmon@4b {
++ compatible = "national,lm92";
++ reg = <0x4b>;
++ };
++ };
++};
+diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
+index 631736e..e2c2381 100644
+--- a/drivers/i2c/busses/Kconfig
++++ b/drivers/i2c/busses/Kconfig
+@@ -628,6 +628,10 @@ config I2C_PXA_SLAVE
+ is necessary for systems where the PXA may be a target on the
+ I2C bus.
+
++config I2C_RALINK
++ tristate "Ralink I2C Controller"
++ select OF_I2C
++
+ config HAVE_S3C2410_I2C
+ bool
+ help
+diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
+index 8f4fc23..7e39a13 100644
+--- a/drivers/i2c/busses/Makefile
++++ b/drivers/i2c/busses/Makefile
+@@ -62,6 +62,7 @@ obj-$(CONFIG_I2C_PNX) += i2c-pnx.o
+ obj-$(CONFIG_I2C_PUV3) += i2c-puv3.o
+ 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_S3C2410) += i2c-s3c2410.o
+ obj-$(CONFIG_I2C_S6000) += i2c-s6000.o
+ obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
+diff --git a/drivers/i2c/busses/i2c-ralink.c b/drivers/i2c/busses/i2c-ralink.c
+new file mode 100644
+index 0000000..f4dc13d
+--- /dev/null
++++ b/drivers/i2c/busses/i2c-ralink.c
+@@ -0,0 +1,274 @@
++/*
++ * drivers/i2c/busses/i2c-ralink.c
++ *
++ * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.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/of_i2c.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 I2C_STARTERR BIT(4)
++#define I2C_ACKERR BIT(3)
++#define I2C_DATARDY BIT(2)
++#define I2C_SDOEMPTY BIT(1)
++#define I2C_BUSY BIT(0)
++
++#define I2C_DEVADLEN_7 (6 << 2)
++#define I2C_ADDRDIS BIT(1)
++
++#define I2C_RETRY 0x400
++
++#define CLKDIV_VALUE 200 // clock rate is 40M, 40M / (200*2) = 100k (standard i2c bus rate).
++//#define CLKDIV_VALUE 50 // clock rate is 40M, 40M / (50*2) = 400k (fast i2c bus rate).
++
++#define READ_CMD 0x01
++#define WRITE_CMD 0x00
++#define READ_BLOCK 64
++
++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 inline int rt_i2c_wait_rx_done(void)
++{
++ int retries = I2C_RETRY;
++
++ do {
++ if (!retries--)
++ break;
++ } while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_DATARDY));
++
++ return (retries < 0);
++}
++
++static inline int rt_i2c_wait_idle(void)
++{
++ int retries = I2C_RETRY;
++
++ do {
++ if (!retries--)
++ break;
++ } while(rt_i2c_r32(REG_STATUS_REG) & I2C_BUSY);
++
++ return (retries < 0);
++}
++
++static inline int rt_i2c_wait_tx_done(void)
++{
++ int retries = I2C_RETRY;
++
++ do {
++ if (!retries--)
++ break;
++ } while(!(rt_i2c_r32(REG_STATUS_REG) & I2C_SDOEMPTY));
++
++ return (retries < 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++) {
++ rt_i2c_wait_idle();
++ 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())
++ return -1;
++ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
++ }
++ }
++
++ rt_i2c_wait_idle();
++ 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())
++ return -1;
++ msg->buf[pos++] = rt_i2c_r32(REG_DATAIN_REG);
++ }
++ } else {
++ rt_i2c_wait_idle();
++ 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);
++ rt_i2c_w32(WRITE_CMD, REG_STARTXFR_REG);
++ if (rt_i2c_wait_tx_done())
++ return -1;
++ }
++ }
++
++ return 0;
++}
++
++static int rt_i2c_master_xfer(struct i2c_adapter *a, struct i2c_msg *m, int n)
++{
++ int i = 0;
++ int ret = 0;
++
++ if (rt_i2c_wait_idle()) {
++ printk("i2c transfer failed\n");
++ return 0;
++ }
++
++ device_reset(a->dev.parent);
++
++ rt_i2c_w32(m->addr, REG_DEVADDR_REG);
++ rt_i2c_w32(I2C_DEVADLEN_7 | I2C_ADDRDIS, REG_CONFIG_REG);
++ rt_i2c_w32(CLKDIV_VALUE, REG_CLKDIV_REG);
++
++ for (i = 0; i < n && !ret; i++)
++ ret = rt_i2c_handle_msg(a, &m[i]);
++
++ if (ret) {
++ printk("i2c transfer failed\n");
++ return 0;
++ }
++
++ return n;
++}
++
++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;
++
++ if (!res) {
++ dev_err(&pdev->dev, "no memory resource found\n");
++ return -ENODEV;
++ }
++
++ 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_request_and_ioremap(&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;
++
++ ret = i2c_add_numbered_adapter(adapter);
++ if (ret)
++ return ret;
++
++ of_i2c_register_devices(adapter);
++
++ platform_set_drvdata(pdev, adapter);
++
++ dev_info(&pdev->dev, "loaded\n");
++
++ 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,rt2880-i2c", },
++ { /* 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-ralink",
++ .of_match_table = i2c_rt_dt_ids,
++ },
++};
++
++static int __init i2c_rt_init (void)
++{
++ return platform_driver_register(&rt_i2c_driver);
++}
++subsys_initcall(i2c_rt_init);
++
++static void __exit i2c_rt_exit (void)
++{
++ platform_driver_unregister(&rt_i2c_driver);
++}
++
++module_exit (i2c_rt_exit);
++
++MODULE_AUTHOR("Steven Liu <steven_liu@mediatek.com>");
++MODULE_DESCRIPTION("Ralink I2c host driver");
++MODULE_LICENSE("GPL");
++MODULE_ALIAS("platform:Ralink-I2C");
+--
+1.7.10.4
+
projects / openwrt / staging / chunkeey.git / blobdiff