--- /dev/null
+/*
+ * I2C bus driver for CSR SiRFprimaII
+ *
+ * Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
+ *
+ * Licensed under GPLv2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#define SIRFSOC_I2C_CLK_CTRL 0x00
+#define SIRFSOC_I2C_STATUS 0x0C
+#define SIRFSOC_I2C_CTRL 0x10
+#define SIRFSOC_I2C_IO_CTRL 0x14
+#define SIRFSOC_I2C_SDA_DELAY 0x18
+#define SIRFSOC_I2C_CMD_START 0x1C
+#define SIRFSOC_I2C_CMD_BUF 0x30
+#define SIRFSOC_I2C_DATA_BUF 0x80
+
+#define SIRFSOC_I2C_CMD_BUF_MAX 16
+#define SIRFSOC_I2C_DATA_BUF_MAX 16
+
+#define SIRFSOC_I2C_CMD(x) (SIRFSOC_I2C_CMD_BUF + (x)*0x04)
+#define SIRFSOC_I2C_DATA_MASK(x) (0xFF<<(((x)&3)*8))
+#define SIRFSOC_I2C_DATA_SHIFT(x) (((x)&3)*8)
+
+#define SIRFSOC_I2C_DIV_MASK (0xFFFF)
+
+/* I2C status flags */
+#define SIRFSOC_I2C_STAT_BUSY BIT(0)
+#define SIRFSOC_I2C_STAT_TIP BIT(1)
+#define SIRFSOC_I2C_STAT_NACK BIT(2)
+#define SIRFSOC_I2C_STAT_TR_INT BIT(4)
+#define SIRFSOC_I2C_STAT_STOP BIT(6)
+#define SIRFSOC_I2C_STAT_CMD_DONE BIT(8)
+#define SIRFSOC_I2C_STAT_ERR BIT(9)
+#define SIRFSOC_I2C_CMD_INDEX (0x1F<<16)
+
+/* I2C control flags */
+#define SIRFSOC_I2C_RESET BIT(0)
+#define SIRFSOC_I2C_CORE_EN BIT(1)
+#define SIRFSOC_I2C_MASTER_MODE BIT(2)
+#define SIRFSOC_I2C_CMD_DONE_EN BIT(11)
+#define SIRFSOC_I2C_ERR_INT_EN BIT(12)
+
+#define SIRFSOC_I2C_SDA_DELAY_MASK (0xFF)
+#define SIRFSOC_I2C_SCLF_FILTER (3<<8)
+
+#define SIRFSOC_I2C_START_CMD BIT(0)
+
+#define SIRFSOC_I2C_CMD_RP(x) ((x)&0x7)
+#define SIRFSOC_I2C_NACK BIT(3)
+#define SIRFSOC_I2C_WRITE BIT(4)
+#define SIRFSOC_I2C_READ BIT(5)
+#define SIRFSOC_I2C_STOP BIT(6)
+#define SIRFSOC_I2C_START BIT(7)
+
+#define SIRFSOC_I2C_DEFAULT_SPEED 100000
+#define SIRFSOC_I2C_ERR_NOACK 1
+#define SIRFSOC_I2C_ERR_TIMEOUT 2
+
+struct sirfsoc_i2c {
+ void __iomem *base;
+ struct clk *clk;
+ u32 cmd_ptr; /* Current position in CMD buffer */
+ u8 *buf; /* Buffer passed by user */
+ u32 msg_len; /* Message length */
+ u32 finished_len; /* number of bytes read/written */
+ u32 read_cmd_len; /* number of read cmd sent */
+ int msg_read; /* 1 indicates a read message */
+ int err_status; /* 1 indicates an error on bus */
+
+ u32 sda_delay; /* For suspend/resume */
+ u32 clk_div;
+ int last; /* Last message in transfer, STOP cmd can be sent */
+
+ struct completion done; /* indicates completion of message transfer */
+ struct i2c_adapter adapter;
+};
+
+static void i2c_sirfsoc_read_data(struct sirfsoc_i2c *siic)
+{
+ u32 data = 0;
+ int i;
+
+ for (i = 0; i < siic->read_cmd_len; i++) {
+ if (!(i & 0x3))
+ data = readl(siic->base + SIRFSOC_I2C_DATA_BUF + i);
+ siic->buf[siic->finished_len++] =
+ (u8)((data & SIRFSOC_I2C_DATA_MASK(i)) >>
+ SIRFSOC_I2C_DATA_SHIFT(i));
+ }
+}
+
+static void i2c_sirfsoc_queue_cmd(struct sirfsoc_i2c *siic)
+{
+ u32 regval;
+ int i = 0;
+
+ if (siic->msg_read) {
+ while (((siic->finished_len + i) < siic->msg_len)
+ && (siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX)) {
+ regval = SIRFSOC_I2C_READ | SIRFSOC_I2C_CMD_RP(0);
+ if (((siic->finished_len + i) ==
+ (siic->msg_len - 1)) && siic->last)
+ regval |= SIRFSOC_I2C_STOP | SIRFSOC_I2C_NACK;
+ writel(regval,
+ siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+ i++;
+ }
+
+ siic->read_cmd_len = i;
+ } else {
+ while ((siic->cmd_ptr < SIRFSOC_I2C_CMD_BUF_MAX - 1)
+ && (siic->finished_len < siic->msg_len)) {
+ regval = SIRFSOC_I2C_WRITE | SIRFSOC_I2C_CMD_RP(0);
+ if ((siic->finished_len == (siic->msg_len - 1))
+ && siic->last)
+ regval |= SIRFSOC_I2C_STOP;
+ writel(regval,
+ siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+ writel(siic->buf[siic->finished_len++],
+ siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+ }
+ }
+ siic->cmd_ptr = 0;
+
+ /* Trigger the transfer */
+ writel(SIRFSOC_I2C_START_CMD, siic->base + SIRFSOC_I2C_CMD_START);
+}
+
+static irqreturn_t i2c_sirfsoc_irq(int irq, void *dev_id)
+{
+ struct sirfsoc_i2c *siic = (struct sirfsoc_i2c *)dev_id;
+ u32 i2c_stat = readl(siic->base + SIRFSOC_I2C_STATUS);
+
+ if (i2c_stat & SIRFSOC_I2C_STAT_ERR) {
+ /* Error conditions */
+ siic->err_status = SIRFSOC_I2C_ERR_NOACK;
+ writel(SIRFSOC_I2C_STAT_ERR, siic->base + SIRFSOC_I2C_STATUS);
+
+ if (i2c_stat & SIRFSOC_I2C_STAT_NACK)
+ dev_dbg(&siic->adapter.dev, "ACK not received\n");
+ else
+ dev_err(&siic->adapter.dev, "I2C error\n");
+
+ /*
+ * Due to hardware ANOMALY, we need to reset I2C earlier after
+ * we get NOACK while accessing non-existing clients, otherwise
+ * we will get errors even we access existing clients later
+ */
+ writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET,
+ siic->base + SIRFSOC_I2C_CTRL);
+ while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
+ cpu_relax();
+
+ complete(&siic->done);
+ } else if (i2c_stat & SIRFSOC_I2C_STAT_CMD_DONE) {
+ /* CMD buffer execution complete */
+ if (siic->msg_read)
+ i2c_sirfsoc_read_data(siic);
+ if (siic->finished_len == siic->msg_len)
+ complete(&siic->done);
+ else /* Fill a new CMD buffer for left data */
+ i2c_sirfsoc_queue_cmd(siic);
+
+ writel(SIRFSOC_I2C_STAT_CMD_DONE, siic->base + SIRFSOC_I2C_STATUS);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static void i2c_sirfsoc_set_address(struct sirfsoc_i2c *siic,
+ struct i2c_msg *msg)
+{
+ unsigned char addr;
+ u32 regval = SIRFSOC_I2C_START | SIRFSOC_I2C_CMD_RP(0) | SIRFSOC_I2C_WRITE;
+
+ /* no data and last message -> add STOP */
+ if (siic->last && (msg->len == 0))
+ regval |= SIRFSOC_I2C_STOP;
+
+ writel(regval, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+
+ addr = msg->addr << 1; /* Generate address */
+ if (msg->flags & I2C_M_RD)
+ addr |= 1;
+
+ /* Reverse direction bit */
+ if (msg->flags & I2C_M_REV_DIR_ADDR)
+ addr ^= 1;
+
+ writel(addr, siic->base + SIRFSOC_I2C_CMD(siic->cmd_ptr++));
+}
+
+static int i2c_sirfsoc_xfer_msg(struct sirfsoc_i2c *siic, struct i2c_msg *msg)
+{
+ u32 regval = readl(siic->base + SIRFSOC_I2C_CTRL);
+ /* timeout waiting for the xfer to finish or fail */
+ int timeout = msecs_to_jiffies((msg->len + 1) * 50);
+
+ i2c_sirfsoc_set_address(siic, msg);
+
+ writel(regval | SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN,
+ siic->base + SIRFSOC_I2C_CTRL);
+ i2c_sirfsoc_queue_cmd(siic);
+
+ if (wait_for_completion_timeout(&siic->done, timeout) == 0) {
+ siic->err_status = SIRFSOC_I2C_ERR_TIMEOUT;
+ dev_err(&siic->adapter.dev, "Transfer timeout\n");
+ }
+
+ writel(regval & ~(SIRFSOC_I2C_CMD_DONE_EN | SIRFSOC_I2C_ERR_INT_EN),
+ siic->base + SIRFSOC_I2C_CTRL);
+ writel(0, siic->base + SIRFSOC_I2C_CMD_START);
+
+ /* i2c control doesn't response, reset it */
+ if (siic->err_status == SIRFSOC_I2C_ERR_TIMEOUT) {
+ writel(readl(siic->base + SIRFSOC_I2C_CTRL) | SIRFSOC_I2C_RESET,
+ siic->base + SIRFSOC_I2C_CTRL);
+ while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
+ cpu_relax();
+ }
+ return siic->err_status ? -EAGAIN : 0;
+}
+
+static u32 i2c_sirfsoc_func(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static int i2c_sirfsoc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct sirfsoc_i2c *siic = adap->algo_data;
+ int i, ret;
+
+ clk_enable(siic->clk);
+
+ for (i = 0; i < num; i++) {
+ siic->buf = msgs[i].buf;
+ siic->msg_len = msgs[i].len;
+ siic->msg_read = !!(msgs[i].flags & I2C_M_RD);
+ siic->err_status = 0;
+ siic->cmd_ptr = 0;
+ siic->finished_len = 0;
+ siic->last = (i == (num - 1));
+
+ ret = i2c_sirfsoc_xfer_msg(siic, &msgs[i]);
+ if (ret) {
+ clk_disable(siic->clk);
+ return ret;
+ }
+ }
+
+ clk_disable(siic->clk);
+ return num;
+}
+
+/* I2C algorithms associated with this master controller driver */
+static const struct i2c_algorithm i2c_sirfsoc_algo = {
+ .master_xfer = i2c_sirfsoc_xfer,
+ .functionality = i2c_sirfsoc_func,
+};
+
+static int i2c_sirfsoc_probe(struct platform_device *pdev)
+{
+ struct sirfsoc_i2c *siic;
+ struct i2c_adapter *adap;
+ struct resource *mem_res;
+ struct clk *clk;
+ int bitrate;
+ int ctrl_speed;
+ int irq;
+
+ int err;
+ u32 regval;
+
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ err = PTR_ERR(clk);
+ dev_err(&pdev->dev, "Clock get failed\n");
+ goto err_get_clk;
+ }
+
+ err = clk_prepare(clk);
+ if (err) {
+ dev_err(&pdev->dev, "Clock prepare failed\n");
+ goto err_clk_prep;
+ }
+
+ err = clk_enable(clk);
+ if (err) {
+ dev_err(&pdev->dev, "Clock enable failed\n");
+ goto err_clk_en;
+ }
+
+ ctrl_speed = clk_get_rate(clk);
+
+ siic = devm_kzalloc(&pdev->dev, sizeof(*siic), GFP_KERNEL);
+ if (!siic) {
+ err = -ENOMEM;
+ goto out;
+ }
+ adap = &siic->adapter;
+ adap->class = I2C_CLASS_DEPRECATED;
+
+ mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ siic->base = devm_ioremap_resource(&pdev->dev, mem_res);
+ if (IS_ERR(siic->base)) {
+ err = PTR_ERR(siic->base);
+ goto out;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ err = irq;
+ goto out;
+ }
+ err = devm_request_irq(&pdev->dev, irq, i2c_sirfsoc_irq, 0,
+ dev_name(&pdev->dev), siic);
+ if (err)
+ goto out;
+
+ adap->algo = &i2c_sirfsoc_algo;
+ adap->algo_data = siic;
+ adap->retries = 3;
+
+ adap->dev.of_node = pdev->dev.of_node;
+ adap->dev.parent = &pdev->dev;
+ adap->nr = pdev->id;
+
+ strlcpy(adap->name, "sirfsoc-i2c", sizeof(adap->name));
+
+ platform_set_drvdata(pdev, adap);
+ init_completion(&siic->done);
+
+ /* Controller Initalisation */
+
+ writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
+ while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
+ cpu_relax();
+ writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE,
+ siic->base + SIRFSOC_I2C_CTRL);
+
+ siic->clk = clk;
+
+ err = of_property_read_u32(pdev->dev.of_node,
+ "clock-frequency", &bitrate);
+ if (err < 0)
+ bitrate = SIRFSOC_I2C_DEFAULT_SPEED;
+
+ if (bitrate < 100000)
+ regval =
+ (2 * ctrl_speed) / (bitrate * 11);
+ else
+ regval = ctrl_speed / (bitrate * 5);
+
+ writel(regval, siic->base + SIRFSOC_I2C_CLK_CTRL);
+ if (regval > 0xFF)
+ writel(0xFF, siic->base + SIRFSOC_I2C_SDA_DELAY);
+ else
+ writel(regval, siic->base + SIRFSOC_I2C_SDA_DELAY);
+
+ err = i2c_add_numbered_adapter(adap);
+ if (err < 0) {
+ dev_err(&pdev->dev, "Can't add new i2c adapter\n");
+ goto out;
+ }
+
+ clk_disable(clk);
+
+ dev_info(&pdev->dev, " I2C adapter ready to operate\n");
+
+ return 0;
+
+out:
+ clk_disable(clk);
+err_clk_en:
+ clk_unprepare(clk);
+err_clk_prep:
+ clk_put(clk);
+err_get_clk:
+ return err;
+}
+
+static int i2c_sirfsoc_remove(struct platform_device *pdev)
+{
+ struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+ struct sirfsoc_i2c *siic = adapter->algo_data;
+
+ writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
+ i2c_del_adapter(adapter);
+ clk_unprepare(siic->clk);
+ clk_put(siic->clk);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int i2c_sirfsoc_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+ struct sirfsoc_i2c *siic = adapter->algo_data;
+
+ clk_enable(siic->clk);
+ siic->sda_delay = readl(siic->base + SIRFSOC_I2C_SDA_DELAY);
+ siic->clk_div = readl(siic->base + SIRFSOC_I2C_CLK_CTRL);
+ clk_disable(siic->clk);
+ return 0;
+}
+
+static int i2c_sirfsoc_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+ struct sirfsoc_i2c *siic = adapter->algo_data;
+
+ clk_enable(siic->clk);
+ writel(SIRFSOC_I2C_RESET, siic->base + SIRFSOC_I2C_CTRL);
+ while (readl(siic->base + SIRFSOC_I2C_CTRL) & SIRFSOC_I2C_RESET)
+ cpu_relax();
+ writel(SIRFSOC_I2C_CORE_EN | SIRFSOC_I2C_MASTER_MODE,
+ siic->base + SIRFSOC_I2C_CTRL);
+ writel(siic->clk_div, siic->base + SIRFSOC_I2C_CLK_CTRL);
+ writel(siic->sda_delay, siic->base + SIRFSOC_I2C_SDA_DELAY);
+ clk_disable(siic->clk);
+ return 0;
+}
+
+static const struct dev_pm_ops i2c_sirfsoc_pm_ops = {
+ .suspend = i2c_sirfsoc_suspend,
+ .resume = i2c_sirfsoc_resume,
+};
+#endif
+
+static const struct of_device_id sirfsoc_i2c_of_match[] = {
+ { .compatible = "sirf,prima2-i2c", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sirfsoc_i2c_of_match);
+
+static struct platform_driver i2c_sirfsoc_driver = {
+ .driver = {
+ .name = "sirfsoc_i2c",
+#ifdef CONFIG_PM
+ .pm = &i2c_sirfsoc_pm_ops,
+#endif
+ .of_match_table = sirfsoc_i2c_of_match,
+ },
+ .probe = i2c_sirfsoc_probe,
+ .remove = i2c_sirfsoc_remove,
+};
+module_platform_driver(i2c_sirfsoc_driver);
+
+MODULE_DESCRIPTION("SiRF SoC I2C master controller driver");
+MODULE_AUTHOR("Zhiwu Song <Zhiwu.Song@csr.com>, "
+ "Xiangzhen Ye <Xiangzhen.Ye@csr.com>");
+MODULE_LICENSE("GPL v2");
Code Review / kvmfornfv.git / blobdiff