--- /dev/null
+/*
+ * Copyright (c) 2014 Linaro Ltd.
+ * Copyright (c) 2014 Hisilicon Limited.
+ *
+ * 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.
+ *
+ * Now only support 7 bit address.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+
+/* Register Map */
+#define HIX5I2C_CTRL 0x00
+#define HIX5I2C_COM 0x04
+#define HIX5I2C_ICR 0x08
+#define HIX5I2C_SR 0x0c
+#define HIX5I2C_SCL_H 0x10
+#define HIX5I2C_SCL_L 0x14
+#define HIX5I2C_TXR 0x18
+#define HIX5I2C_RXR 0x1c
+
+/* I2C_CTRL_REG */
+#define I2C_ENABLE BIT(8)
+#define I2C_UNMASK_TOTAL BIT(7)
+#define I2C_UNMASK_START BIT(6)
+#define I2C_UNMASK_END BIT(5)
+#define I2C_UNMASK_SEND BIT(4)
+#define I2C_UNMASK_RECEIVE BIT(3)
+#define I2C_UNMASK_ACK BIT(2)
+#define I2C_UNMASK_ARBITRATE BIT(1)
+#define I2C_UNMASK_OVER BIT(0)
+#define I2C_UNMASK_ALL (I2C_UNMASK_ACK | I2C_UNMASK_OVER)
+
+/* I2C_COM_REG */
+#define I2C_NO_ACK BIT(4)
+#define I2C_START BIT(3)
+#define I2C_READ BIT(2)
+#define I2C_WRITE BIT(1)
+#define I2C_STOP BIT(0)
+
+/* I2C_ICR_REG */
+#define I2C_CLEAR_START BIT(6)
+#define I2C_CLEAR_END BIT(5)
+#define I2C_CLEAR_SEND BIT(4)
+#define I2C_CLEAR_RECEIVE BIT(3)
+#define I2C_CLEAR_ACK BIT(2)
+#define I2C_CLEAR_ARBITRATE BIT(1)
+#define I2C_CLEAR_OVER BIT(0)
+#define I2C_CLEAR_ALL (I2C_CLEAR_START | I2C_CLEAR_END | \
+ I2C_CLEAR_SEND | I2C_CLEAR_RECEIVE | \
+ I2C_CLEAR_ACK | I2C_CLEAR_ARBITRATE | \
+ I2C_CLEAR_OVER)
+
+/* I2C_SR_REG */
+#define I2C_BUSY BIT(7)
+#define I2C_START_INTR BIT(6)
+#define I2C_END_INTR BIT(5)
+#define I2C_SEND_INTR BIT(4)
+#define I2C_RECEIVE_INTR BIT(3)
+#define I2C_ACK_INTR BIT(2)
+#define I2C_ARBITRATE_INTR BIT(1)
+#define I2C_OVER_INTR BIT(0)
+
+#define HIX5I2C_MAX_FREQ 400000 /* 400k */
+#define HIX5I2C_READ_OPERATION 0x01
+
+enum hix5hd2_i2c_state {
+ HIX5I2C_STAT_RW_ERR = -1,
+ HIX5I2C_STAT_INIT,
+ HIX5I2C_STAT_RW,
+ HIX5I2C_STAT_SND_STOP,
+ HIX5I2C_STAT_RW_SUCCESS,
+};
+
+struct hix5hd2_i2c_priv {
+ struct i2c_adapter adap;
+ struct i2c_msg *msg;
+ struct completion msg_complete;
+ unsigned int msg_idx;
+ unsigned int msg_len;
+ int stop;
+ void __iomem *regs;
+ struct clk *clk;
+ struct device *dev;
+ spinlock_t lock; /* IRQ synchronization */
+ int err;
+ unsigned int freq;
+ enum hix5hd2_i2c_state state;
+};
+
+static u32 hix5hd2_i2c_clr_pend_irq(struct hix5hd2_i2c_priv *priv)
+{
+ u32 val = readl_relaxed(priv->regs + HIX5I2C_SR);
+
+ writel_relaxed(val, priv->regs + HIX5I2C_ICR);
+
+ return val;
+}
+
+static void hix5hd2_i2c_clr_all_irq(struct hix5hd2_i2c_priv *priv)
+{
+ writel_relaxed(I2C_CLEAR_ALL, priv->regs + HIX5I2C_ICR);
+}
+
+static void hix5hd2_i2c_disable_irq(struct hix5hd2_i2c_priv *priv)
+{
+ writel_relaxed(0, priv->regs + HIX5I2C_CTRL);
+}
+
+static void hix5hd2_i2c_enable_irq(struct hix5hd2_i2c_priv *priv)
+{
+ writel_relaxed(I2C_ENABLE | I2C_UNMASK_TOTAL | I2C_UNMASK_ALL,
+ priv->regs + HIX5I2C_CTRL);
+}
+
+static void hix5hd2_i2c_drv_setrate(struct hix5hd2_i2c_priv *priv)
+{
+ u32 rate, val;
+ u32 scl, sysclock;
+
+ /* close all i2c interrupt */
+ val = readl_relaxed(priv->regs + HIX5I2C_CTRL);
+ writel_relaxed(val & (~I2C_UNMASK_TOTAL), priv->regs + HIX5I2C_CTRL);
+
+ rate = priv->freq;
+ sysclock = clk_get_rate(priv->clk);
+ scl = (sysclock / (rate * 2)) / 2 - 1;
+ writel_relaxed(scl, priv->regs + HIX5I2C_SCL_H);
+ writel_relaxed(scl, priv->regs + HIX5I2C_SCL_L);
+
+ /* restore original interrupt*/
+ writel_relaxed(val, priv->regs + HIX5I2C_CTRL);
+
+ dev_dbg(priv->dev, "%s: sysclock=%d, rate=%d, scl=%d\n",
+ __func__, sysclock, rate, scl);
+}
+
+static void hix5hd2_i2c_init(struct hix5hd2_i2c_priv *priv)
+{
+ hix5hd2_i2c_disable_irq(priv);
+ hix5hd2_i2c_drv_setrate(priv);
+ hix5hd2_i2c_clr_all_irq(priv);
+ hix5hd2_i2c_enable_irq(priv);
+}
+
+static void hix5hd2_i2c_reset(struct hix5hd2_i2c_priv *priv)
+{
+ clk_disable_unprepare(priv->clk);
+ msleep(20);
+ clk_prepare_enable(priv->clk);
+ hix5hd2_i2c_init(priv);
+}
+
+static int hix5hd2_i2c_wait_bus_idle(struct hix5hd2_i2c_priv *priv)
+{
+ unsigned long stop_time;
+ u32 int_status;
+
+ /* wait for 100 milli seconds for the bus to be idle */
+ stop_time = jiffies + msecs_to_jiffies(100);
+ do {
+ int_status = hix5hd2_i2c_clr_pend_irq(priv);
+ if (!(int_status & I2C_BUSY))
+ return 0;
+
+ usleep_range(50, 200);
+ } while (time_before(jiffies, stop_time));
+
+ return -EBUSY;
+}
+
+static void hix5hd2_rw_over(struct hix5hd2_i2c_priv *priv)
+{
+ if (priv->state == HIX5I2C_STAT_SND_STOP)
+ dev_dbg(priv->dev, "%s: rw and send stop over\n", __func__);
+ else
+ dev_dbg(priv->dev, "%s: have not data to send\n", __func__);
+
+ priv->state = HIX5I2C_STAT_RW_SUCCESS;
+ priv->err = 0;
+}
+
+static void hix5hd2_rw_handle_stop(struct hix5hd2_i2c_priv *priv)
+{
+ if (priv->stop) {
+ priv->state = HIX5I2C_STAT_SND_STOP;
+ writel_relaxed(I2C_STOP, priv->regs + HIX5I2C_COM);
+ } else {
+ hix5hd2_rw_over(priv);
+ }
+}
+
+static void hix5hd2_read_handle(struct hix5hd2_i2c_priv *priv)
+{
+ if (priv->msg_len == 1) {
+ /* the last byte don't need send ACK */
+ writel_relaxed(I2C_READ | I2C_NO_ACK, priv->regs + HIX5I2C_COM);
+ } else if (priv->msg_len > 1) {
+ /* if i2c master receive data will send ACK */
+ writel_relaxed(I2C_READ, priv->regs + HIX5I2C_COM);
+ } else {
+ hix5hd2_rw_handle_stop(priv);
+ }
+}
+
+static void hix5hd2_write_handle(struct hix5hd2_i2c_priv *priv)
+{
+ u8 data;
+
+ if (priv->msg_len > 0) {
+ data = priv->msg->buf[priv->msg_idx++];
+ writel_relaxed(data, priv->regs + HIX5I2C_TXR);
+ writel_relaxed(I2C_WRITE, priv->regs + HIX5I2C_COM);
+ } else {
+ hix5hd2_rw_handle_stop(priv);
+ }
+}
+
+static int hix5hd2_rw_preprocess(struct hix5hd2_i2c_priv *priv)
+{
+ u8 data;
+
+ if (priv->state == HIX5I2C_STAT_INIT) {
+ priv->state = HIX5I2C_STAT_RW;
+ } else if (priv->state == HIX5I2C_STAT_RW) {
+ if (priv->msg->flags & I2C_M_RD) {
+ data = readl_relaxed(priv->regs + HIX5I2C_RXR);
+ priv->msg->buf[priv->msg_idx++] = data;
+ }
+ priv->msg_len--;
+ } else {
+ dev_dbg(priv->dev, "%s: error: priv->state = %d, msg_len = %d\n",
+ __func__, priv->state, priv->msg_len);
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static irqreturn_t hix5hd2_i2c_irq(int irqno, void *dev_id)
+{
+ struct hix5hd2_i2c_priv *priv = dev_id;
+ u32 int_status;
+ int ret;
+
+ spin_lock(&priv->lock);
+
+ int_status = hix5hd2_i2c_clr_pend_irq(priv);
+
+ /* handle error */
+ if (int_status & I2C_ARBITRATE_INTR) {
+ /* bus error */
+ dev_dbg(priv->dev, "ARB bus loss\n");
+ priv->err = -EAGAIN;
+ priv->state = HIX5I2C_STAT_RW_ERR;
+ goto stop;
+ } else if (int_status & I2C_ACK_INTR) {
+ /* ack error */
+ dev_dbg(priv->dev, "No ACK from device\n");
+ priv->err = -ENXIO;
+ priv->state = HIX5I2C_STAT_RW_ERR;
+ goto stop;
+ }
+
+ if (int_status & I2C_OVER_INTR) {
+ if (priv->msg_len > 0) {
+ ret = hix5hd2_rw_preprocess(priv);
+ if (ret) {
+ priv->err = ret;
+ priv->state = HIX5I2C_STAT_RW_ERR;
+ goto stop;
+ }
+ if (priv->msg->flags & I2C_M_RD)
+ hix5hd2_read_handle(priv);
+ else
+ hix5hd2_write_handle(priv);
+ } else {
+ hix5hd2_rw_over(priv);
+ }
+ }
+
+stop:
+ if ((priv->state == HIX5I2C_STAT_RW_SUCCESS &&
+ priv->msg->len == priv->msg_idx) ||
+ (priv->state == HIX5I2C_STAT_RW_ERR)) {
+ hix5hd2_i2c_disable_irq(priv);
+ hix5hd2_i2c_clr_pend_irq(priv);
+ complete(&priv->msg_complete);
+ }
+
+ spin_unlock(&priv->lock);
+
+ return IRQ_HANDLED;
+}
+
+static void hix5hd2_i2c_message_start(struct hix5hd2_i2c_priv *priv, int stop)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->lock, flags);
+ hix5hd2_i2c_clr_all_irq(priv);
+ hix5hd2_i2c_enable_irq(priv);
+
+ if (priv->msg->flags & I2C_M_RD)
+ writel_relaxed((priv->msg->addr << 1) | HIX5I2C_READ_OPERATION,
+ priv->regs + HIX5I2C_TXR);
+ else
+ writel_relaxed(priv->msg->addr << 1,
+ priv->regs + HIX5I2C_TXR);
+
+ writel_relaxed(I2C_WRITE | I2C_START, priv->regs + HIX5I2C_COM);
+ spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static int hix5hd2_i2c_xfer_msg(struct hix5hd2_i2c_priv *priv,
+ struct i2c_msg *msgs, int stop)
+{
+ unsigned long timeout;
+ int ret;
+
+ priv->msg = msgs;
+ priv->msg_idx = 0;
+ priv->msg_len = priv->msg->len;
+ priv->stop = stop;
+ priv->err = 0;
+ priv->state = HIX5I2C_STAT_INIT;
+
+ reinit_completion(&priv->msg_complete);
+ hix5hd2_i2c_message_start(priv, stop);
+
+ timeout = wait_for_completion_timeout(&priv->msg_complete,
+ priv->adap.timeout);
+ if (timeout == 0) {
+ priv->state = HIX5I2C_STAT_RW_ERR;
+ priv->err = -ETIMEDOUT;
+ dev_warn(priv->dev, "%s timeout=%d\n",
+ msgs->flags & I2C_M_RD ? "rx" : "tx",
+ priv->adap.timeout);
+ }
+ ret = priv->state;
+
+ /*
+ * If this is the last message to be transfered (stop == 1)
+ * Then check if the bus can be brought back to idle.
+ */
+ if (priv->state == HIX5I2C_STAT_RW_SUCCESS && stop)
+ ret = hix5hd2_i2c_wait_bus_idle(priv);
+
+ if (ret < 0)
+ hix5hd2_i2c_reset(priv);
+
+ return priv->err;
+}
+
+static int hix5hd2_i2c_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct hix5hd2_i2c_priv *priv = i2c_get_adapdata(adap);
+ int i, ret, stop;
+
+ pm_runtime_get_sync(priv->dev);
+
+ for (i = 0; i < num; i++, msgs++) {
+ stop = (i == num - 1);
+ ret = hix5hd2_i2c_xfer_msg(priv, msgs, stop);
+ if (ret < 0)
+ goto out;
+ }
+
+ if (i == num) {
+ ret = num;
+ } else {
+ /* Only one message, cannot access the device */
+ if (i == 1)
+ ret = -EREMOTEIO;
+ else
+ ret = i;
+
+ dev_warn(priv->dev, "xfer message failed\n");
+ }
+
+out:
+ pm_runtime_mark_last_busy(priv->dev);
+ pm_runtime_put_autosuspend(priv->dev);
+ return ret;
+}
+
+static u32 hix5hd2_i2c_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm hix5hd2_i2c_algorithm = {
+ .master_xfer = hix5hd2_i2c_xfer,
+ .functionality = hix5hd2_i2c_func,
+};
+
+static int hix5hd2_i2c_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct hix5hd2_i2c_priv *priv;
+ struct resource *mem;
+ unsigned int freq;
+ int irq, ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ if (of_property_read_u32(np, "clock-frequency", &freq)) {
+ /* use 100k as default value */
+ priv->freq = 100000;
+ } else {
+ if (freq > HIX5I2C_MAX_FREQ) {
+ priv->freq = HIX5I2C_MAX_FREQ;
+ dev_warn(priv->dev, "use max freq %d instead\n",
+ HIX5I2C_MAX_FREQ);
+ } else {
+ priv->freq = freq;
+ }
+ }
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->regs = devm_ioremap_resource(&pdev->dev, mem);
+ if (IS_ERR(priv->regs))
+ return PTR_ERR(priv->regs);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq <= 0) {
+ dev_err(&pdev->dev, "cannot find HS-I2C IRQ\n");
+ return irq;
+ }
+
+ priv->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ dev_err(&pdev->dev, "cannot get clock\n");
+ return PTR_ERR(priv->clk);
+ }
+ clk_prepare_enable(priv->clk);
+
+ strlcpy(priv->adap.name, "hix5hd2-i2c", sizeof(priv->adap.name));
+ priv->dev = &pdev->dev;
+ priv->adap.owner = THIS_MODULE;
+ priv->adap.algo = &hix5hd2_i2c_algorithm;
+ priv->adap.retries = 3;
+ priv->adap.dev.of_node = np;
+ priv->adap.algo_data = priv;
+ priv->adap.dev.parent = &pdev->dev;
+ i2c_set_adapdata(&priv->adap, priv);
+ platform_set_drvdata(pdev, priv);
+ spin_lock_init(&priv->lock);
+ init_completion(&priv->msg_complete);
+
+ hix5hd2_i2c_init(priv);
+
+ ret = devm_request_irq(&pdev->dev, irq, hix5hd2_i2c_irq,
+ IRQF_NO_SUSPEND | IRQF_ONESHOT,
+ dev_name(&pdev->dev), priv);
+ if (ret != 0) {
+ dev_err(&pdev->dev, "cannot request HS-I2C IRQ %d\n", irq);
+ goto err_clk;
+ }
+
+ pm_suspend_ignore_children(&pdev->dev, true);
+ pm_runtime_set_autosuspend_delay(priv->dev, MSEC_PER_SEC);
+ pm_runtime_use_autosuspend(priv->dev);
+ pm_runtime_set_active(priv->dev);
+ pm_runtime_enable(priv->dev);
+
+ ret = i2c_add_adapter(&priv->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to add bus to i2c core\n");
+ goto err_runtime;
+ }
+
+ return ret;
+
+err_runtime:
+ pm_runtime_disable(priv->dev);
+ pm_runtime_set_suspended(priv->dev);
+err_clk:
+ clk_disable_unprepare(priv->clk);
+ return ret;
+}
+
+static int hix5hd2_i2c_remove(struct platform_device *pdev)
+{
+ struct hix5hd2_i2c_priv *priv = platform_get_drvdata(pdev);
+
+ i2c_del_adapter(&priv->adap);
+ pm_runtime_disable(priv->dev);
+ pm_runtime_set_suspended(priv->dev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int hix5hd2_i2c_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct hix5hd2_i2c_priv *priv = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(priv->clk);
+
+ return 0;
+}
+
+static int hix5hd2_i2c_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct hix5hd2_i2c_priv *priv = platform_get_drvdata(pdev);
+
+ clk_prepare_enable(priv->clk);
+ hix5hd2_i2c_init(priv);
+
+ return 0;
+}
+#endif
+
+static const struct dev_pm_ops hix5hd2_i2c_pm_ops = {
+ SET_PM_RUNTIME_PM_OPS(hix5hd2_i2c_runtime_suspend,
+ hix5hd2_i2c_runtime_resume,
+ NULL)
+};
+
+static const struct of_device_id hix5hd2_i2c_match[] = {
+ { .compatible = "hisilicon,hix5hd2-i2c" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, hix5hd2_i2c_match);
+
+static struct platform_driver hix5hd2_i2c_driver = {
+ .probe = hix5hd2_i2c_probe,
+ .remove = hix5hd2_i2c_remove,
+ .driver = {
+ .name = "hix5hd2-i2c",
+ .pm = &hix5hd2_i2c_pm_ops,
+ .of_match_table = hix5hd2_i2c_match,
+ },
+};
+
+module_platform_driver(hix5hd2_i2c_driver);
+
+MODULE_DESCRIPTION("Hix5hd2 I2C Bus driver");
+MODULE_AUTHOR("Wei Yan <sledge.yanwei@huawei.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:i2c-hix5hd2");
projects / firefly-linux-kernel-4.4.55.git / commitdiff