--- /dev/null
+From 723b8beaabf3c3c4b1ce69480141f1e926f3f3b2 Mon Sep 17 00:00:00 2001
+From: John Crispin <blogic@openwrt.org>
+Date: Sun, 27 Jul 2014 09:52:56 +0100
+Subject: [PATCH 44/53] 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 | 327 ++++++++++++++++++++
+ 4 files changed, 359 insertions(+)
+ create mode 100644 Documentation/devicetree/bindings/i2c/i2c-ralink.txt
+ create mode 100644 drivers/i2c/busses/i2c-ralink.c
+
+--- /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>;
++ };
++ };
++};
+--- a/drivers/i2c/busses/Kconfig
++++ b/drivers/i2c/busses/Kconfig
+@@ -863,6 +863,11 @@ config I2C_RK3X
+ This driver can also be built as a module. If so, the module will
+ be called i2c-rk3x.
+
++config I2C_RALINK
++ tristate "Ralink I2C Controller"
++ depends on RALINK && !SOC_MT7621
++ select OF_I2C
++
+ config HAVE_S3C2410_I2C
+ bool
+ help
+--- a/drivers/i2c/busses/Makefile
++++ b/drivers/i2c/busses/Makefile
+@@ -84,6 +84,7 @@ 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_QUP) += i2c-qup.o
+ obj-$(CONFIG_I2C_RIIC) += i2c-riic.o
+ obj-$(CONFIG_I2C_RK3X) += i2c-rk3x.o
+--- /dev/null
++++ b/drivers/i2c/busses/i2c-ralink.c
+@@ -0,0 +1,435 @@
++/*
++ * drivers/i2c/busses/i2c-ralink.c
++ *
++ * Copyright (C) 2013 Steven Liu <steven_liu@mediatek.com>
++ * Copyright (C) 2016 Michael Lee <igvtee@gmail.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/of_platform.h>
++#include <linux/i2c.h>
++#include <linux/io.h>
++#include <linux/err.h>
++#include <linux/clk.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
++
++/* REG_CONFIG_REG */
++#define I2C_ADDRLEN_OFFSET 5
++#define I2C_DEVADLEN_OFFSET 2
++#define I2C_ADDRLEN_MASK 0x3
++#define I2C_ADDR_DIS BIT(1)
++#define I2C_DEVADDR_DIS BIT(0)
++#define I2C_ADDRLEN_8 (7 << I2C_ADDRLEN_OFFSET)
++#define I2C_DEVADLEN_7 (6 << I2C_DEVADLEN_OFFSET)
++#define I2C_CONF_DEFAULT (I2C_ADDRLEN_8 | I2C_DEVADLEN_7)
++
++/* REG_CLKDIV_REG */
++#define I2C_CLKDIV_MASK 0xffff
++
++/* REG_DEVADDR_REG */
++#define I2C_DEVADDR_MASK 0x7f
++
++/* REG_ADDR_REG */
++#define I2C_ADDR_MASK 0xff
++
++/* REG_STATUS_REG */
++#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)
++
++/* REG_STARTXFR_REG */
++#define NOSTOP_CMD BIT(2)
++#define NODATA_CMD BIT(1)
++#define READ_CMD BIT(0)
++
++/* REG_BYTECNT_REG */
++#define BYTECNT_MAX 64
++#define SET_BYTECNT(x) (x - 1)
++
++/* timeout waiting for I2C devices to respond (clock streching) */
++#define TIMEOUT_MS 1000
++#define DELAY_INTERVAL_US 100
++
++struct rt_i2c {
++ void __iomem *base;
++ struct clk *clk;
++ struct device *dev;
++ struct i2c_adapter adap;
++ u32 cur_clk;
++ u32 clk_div;
++ u32 flags;
++};
++
++static void rt_i2c_w32(struct rt_i2c *i2c, u32 val, unsigned reg)
++{
++ iowrite32(val, i2c->base + reg);
++}
++
++static u32 rt_i2c_r32(struct rt_i2c *i2c, unsigned reg)
++{
++ return ioread32(i2c->base + reg);
++}
++
++static int poll_down_timeout(void __iomem *addr, u32 mask)
++{
++ unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS);
++
++ do {
++ if (!(readl_relaxed(addr) & mask))
++ return 0;
++
++ usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50);
++ } while (time_before(jiffies, timeout));
++
++ return (readl_relaxed(addr) & mask) ? -EAGAIN : 0;
++}
++
++static int rt_i2c_wait_idle(struct rt_i2c *i2c)
++{
++ int ret;
++
++ ret = poll_down_timeout(i2c->base + REG_STATUS_REG, I2C_BUSY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "idle err(%d)\n", ret);
++
++ return ret;
++}
++
++static int poll_up_timeout(void __iomem *addr, u32 mask)
++{
++ unsigned long timeout = jiffies + msecs_to_jiffies(TIMEOUT_MS);
++ u32 status;
++
++ do {
++ status = readl_relaxed(addr);
++
++ /* check error status */
++ if (status & I2C_STARTERR)
++ return -EAGAIN;
++ else if (status & I2C_ACKERR)
++ return -ENXIO;
++ else if (status & mask)
++ return 0;
++
++ usleep_range(DELAY_INTERVAL_US, DELAY_INTERVAL_US + 50);
++ } while (time_before(jiffies, timeout));
++
++ return -ETIMEDOUT;
++}
++
++static int rt_i2c_wait_rx_done(struct rt_i2c *i2c)
++{
++ int ret;
++
++ ret = poll_up_timeout(i2c->base + REG_STATUS_REG, I2C_DATARDY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "rx err(%d)\n", ret);
++
++ return ret;
++}
++
++static int rt_i2c_wait_tx_done(struct rt_i2c *i2c)
++{
++ int ret;
++
++ ret = poll_up_timeout(i2c->base + REG_STATUS_REG, I2C_SDOEMPTY);
++ if (ret < 0)
++ dev_dbg(i2c->dev, "tx err(%d)\n", ret);
++
++ return ret;
++}
++
++static void rt_i2c_reset(struct rt_i2c *i2c)
++{
++ device_reset(i2c->adap.dev.parent);
++ barrier();
++ rt_i2c_w32(i2c, i2c->clk_div, REG_CLKDIV_REG);
++}
++
++static void rt_i2c_dump_reg(struct rt_i2c *i2c)
++{
++ dev_dbg(i2c->dev, "conf %08x, clkdiv %08x, devaddr %08x, " \
++ "addr %08x, dataout %08x, datain %08x, " \
++ "status %08x, startxfr %08x, bytecnt %08x\n",
++ rt_i2c_r32(i2c, REG_CONFIG_REG),
++ rt_i2c_r32(i2c, REG_CLKDIV_REG),
++ rt_i2c_r32(i2c, REG_DEVADDR_REG),
++ rt_i2c_r32(i2c, REG_ADDR_REG),
++ rt_i2c_r32(i2c, REG_DATAOUT_REG),
++ rt_i2c_r32(i2c, REG_DATAIN_REG),
++ rt_i2c_r32(i2c, REG_STATUS_REG),
++ rt_i2c_r32(i2c, REG_STARTXFR_REG),
++ rt_i2c_r32(i2c, REG_BYTECNT_REG));
++}
++
++static int rt_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
++ int num)
++{
++ struct rt_i2c *i2c;
++ struct i2c_msg *pmsg;
++ unsigned char addr;
++ int i, j, ret;
++ u32 cmd;
++
++ i2c = i2c_get_adapdata(adap);
++
++ for (i = 0; i < num; i++) {
++ pmsg = &msgs[i];
++ if (i == (num - 1))
++ cmd = 0;
++ else
++ cmd = NOSTOP_CMD;
++
++ dev_dbg(i2c->dev, "addr: 0x%x, len: %d, flags: 0x%x, stop: %d\n",
++ pmsg->addr, pmsg->len, pmsg->flags,
++ (cmd == 0)? 1 : 0);
++
++ /* wait hardware idle */
++ if ((ret = rt_i2c_wait_idle(i2c)))
++ goto err_timeout;
++
++ if (pmsg->flags & I2C_M_TEN) {
++ rt_i2c_w32(i2c, I2C_CONF_DEFAULT, REG_CONFIG_REG);
++ /* 10 bits address */
++ addr = 0x78 | ((pmsg->addr >> 8) & 0x03);
++ rt_i2c_w32(i2c, addr & I2C_DEVADDR_MASK,
++ REG_DEVADDR_REG);
++ rt_i2c_w32(i2c, pmsg->addr & I2C_ADDR_MASK,
++ REG_ADDR_REG);
++ } else {
++ rt_i2c_w32(i2c, I2C_CONF_DEFAULT | I2C_ADDR_DIS,
++ REG_CONFIG_REG);
++ /* 7 bits address */
++ rt_i2c_w32(i2c, pmsg->addr & I2C_DEVADDR_MASK,
++ REG_DEVADDR_REG);
++ }
++
++ /* buffer length */
++ if (pmsg->len == 0)
++ cmd |= NODATA_CMD;
++ else
++ rt_i2c_w32(i2c, SET_BYTECNT(pmsg->len),
++ REG_BYTECNT_REG);
++
++ j = 0;
++ if (pmsg->flags & I2C_M_RD) {
++ cmd |= READ_CMD;
++ /* start transfer */
++ barrier();
++ rt_i2c_w32(i2c, cmd, REG_STARTXFR_REG);
++ do {
++ /* wait */
++ if ((ret = rt_i2c_wait_rx_done(i2c)))
++ goto err_timeout;
++ /* read data */
++ if (pmsg->len)
++ pmsg->buf[j] = rt_i2c_r32(i2c,
++ REG_DATAIN_REG);
++ j++;
++ } while (j < pmsg->len);
++ } else {
++ do {
++ /* write data */
++ if (pmsg->len)
++ rt_i2c_w32(i2c, pmsg->buf[j],
++ REG_DATAOUT_REG);
++ /* start transfer */
++ if (j == 0) {
++ barrier();
++ rt_i2c_w32(i2c, cmd, REG_STARTXFR_REG);
++ }
++ /* wait */
++ if ((ret = rt_i2c_wait_tx_done(i2c)))
++ goto err_timeout;
++ j++;
++ } while (j < pmsg->len);
++ }
++ }
++ /* the return value is number of executed messages */
++ ret = i;
++
++ return ret;
++
++err_timeout:
++ rt_i2c_dump_reg(i2c);
++ rt_i2c_reset(i2c);
++ return ret;
++}
++
++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 const struct of_device_id i2c_rt_dt_ids[] = {
++ { .compatible = "ralink,rt2880-i2c" },
++ { /* sentinel */ }
++};
++
++MODULE_DEVICE_TABLE(of, i2c_rt_dt_ids);
++
++static struct i2c_adapter_quirks rt_i2c_quirks = {
++ .max_write_len = BYTECNT_MAX,
++ .max_read_len = BYTECNT_MAX,
++};
++
++static int rt_i2c_init(struct rt_i2c *i2c)
++{
++ u32 reg;
++
++ /* i2c_sclk = periph_clk / ((2 * clk_div) + 5) */
++ i2c->clk_div = (clk_get_rate(i2c->clk) - (5 * i2c->cur_clk)) /
++ (2 * i2c->cur_clk);
++ if (i2c->clk_div < 8)
++ i2c->clk_div = 8;
++ if (i2c->clk_div > I2C_CLKDIV_MASK)
++ i2c->clk_div = I2C_CLKDIV_MASK;
++
++ /* check support combinde/repeated start message */
++ rt_i2c_w32(i2c, NOSTOP_CMD, REG_STARTXFR_REG);
++ reg = rt_i2c_r32(i2c, REG_STARTXFR_REG) & NOSTOP_CMD;
++
++ rt_i2c_reset(i2c);
++
++ return reg;
++}
++
++static int rt_i2c_probe(struct platform_device *pdev)
++{
++ struct resource *res;
++ struct rt_i2c *i2c;
++ struct i2c_adapter *adap;
++ const struct of_device_id *match;
++ int ret, restart;
++
++ match = of_match_device(i2c_rt_dt_ids, &pdev->dev);
++
++ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++ if (!res) {
++ dev_err(&pdev->dev, "no memory resource found\n");
++ return -ENODEV;
++ }
++
++ i2c = devm_kzalloc(&pdev->dev, sizeof(struct rt_i2c), GFP_KERNEL);
++ if (!i2c) {
++ dev_err(&pdev->dev, "failed to allocate i2c_adapter\n");
++ return -ENOMEM;
++ }
++
++ i2c->base = devm_ioremap_resource(&pdev->dev, res);
++ if (IS_ERR(i2c->base))
++ return PTR_ERR(i2c->base);
++
++ i2c->clk = devm_clk_get(&pdev->dev, NULL);
++ if (IS_ERR(i2c->clk)) {
++ dev_err(&pdev->dev, "no clock defined\n");
++ return -ENODEV;
++ }
++ clk_prepare_enable(i2c->clk);
++ i2c->dev = &pdev->dev;
++
++ if (of_property_read_u32(pdev->dev.of_node,
++ "clock-frequency", &i2c->cur_clk))
++ i2c->cur_clk = 100000;
++
++ adap = &i2c->adap;
++ adap->owner = THIS_MODULE;
++ adap->class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
++ adap->algo = &rt_i2c_algo;
++ adap->retries = 3;
++ adap->dev.parent = &pdev->dev;
++ i2c_set_adapdata(adap, i2c);
++ adap->dev.of_node = pdev->dev.of_node;
++ strlcpy(adap->name, dev_name(&pdev->dev), sizeof(adap->name));
++ adap->quirks = &rt_i2c_quirks;
++
++ platform_set_drvdata(pdev, i2c);
++
++ restart = rt_i2c_init(i2c);
++
++ ret = i2c_add_adapter(adap);
++ if (ret < 0) {
++ dev_err(&pdev->dev, "failed to add adapter\n");
++ clk_disable_unprepare(i2c->clk);
++ return ret;
++ }
++
++ dev_info(&pdev->dev, "clock %uKHz, re-start %ssupport\n",
++ i2c->cur_clk/1000, restart ? "" : "not ");
++
++ return ret;
++}
++
++static int rt_i2c_remove(struct platform_device *pdev)
++{
++ struct rt_i2c *i2c = platform_get_drvdata(pdev);
++
++ i2c_del_adapter(&i2c->adap);
++ clk_disable_unprepare(i2c->clk);
++
++ return 0;
++}
++
++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");
projects / openwrt / staging / kaloz.git / blobdiff