+++ /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
-@@ -864,6 +864,11 @@ 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 / openwrt.git / blobdiff