--- /dev/null
+/*
+ * I2C driver for PKUnity-v3 SoC
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Maintained by GUAN Xue-tao <gxt@mprc.pku.edu.cn>
+ * Copyright (C) 2001-2010 Guan Xuetao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/clk.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <mach/hardware.h>
+
+/*
+ * Poll the i2c status register until the specified bit is set.
+ * Returns 0 if timed out (100 msec).
+ */
+static short poll_status(unsigned long bit)
+{
+ int loop_cntr = 1000;
+
+ if (bit & I2C_STATUS_TFNF) {
+ do {
+ udelay(10);
+ } while (!(readl(I2C_STATUS) & bit) && (--loop_cntr > 0));
+ } else {
+ /* RXRDY handler */
+ do {
+ if (readl(I2C_TAR) == I2C_TAR_EEPROM)
+ msleep(20);
+ else
+ udelay(10);
+ } while (!(readl(I2C_RXFLR) & 0xf) && (--loop_cntr > 0));
+ }
+
+ return (loop_cntr > 0);
+}
+
+static int xfer_read(struct i2c_adapter *adap, unsigned char *buf, int length)
+{
+ int i2c_reg = *buf;
+
+ /* Read data */
+ while (length--) {
+ if (!poll_status(I2C_STATUS_TFNF)) {
+ dev_dbg(&adap->dev, "Tx FIFO Not Full timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ /* send addr */
+ writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD);
+
+ /* get ready to next write */
+ i2c_reg++;
+
+ /* send read CMD */
+ writel(I2C_DATACMD_READ, I2C_DATACMD);
+
+ /* wait until the Rx FIFO have available */
+ if (!poll_status(I2C_STATUS_RFNE)) {
+ dev_dbg(&adap->dev, "RXRDY timeout\n");
+ return -ETIMEDOUT;
+ }
+
+ /* read the data to buf */
+ *buf = (readl(I2C_DATACMD) & I2C_DATACMD_DAT_MASK);
+ buf++;
+ }
+
+ return 0;
+}
+
+static int xfer_write(struct i2c_adapter *adap, unsigned char *buf, int length)
+{
+ int i2c_reg = *buf;
+
+ /* Do nothing but storing the reg_num to a static variable */
+ if (i2c_reg == -1) {
+ printk(KERN_WARNING "Error i2c reg\n");
+ return -ETIMEDOUT;
+ }
+
+ if (length == 1)
+ return 0;
+
+ buf++;
+ length--;
+ while (length--) {
+ /* send addr */
+ writel(i2c_reg | I2C_DATACMD_WRITE, I2C_DATACMD);
+
+ /* send write CMD */
+ writel(*buf | I2C_DATACMD_WRITE, I2C_DATACMD);
+
+ /* wait until the Rx FIFO have available */
+ msleep(20);
+
+ /* read the data to buf */
+ i2c_reg++;
+ buf++;
+ }
+
+ return 0;
+}
+
+/*
+ * Generic i2c master transfer entrypoint.
+ *
+ */
+static int puv3_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *pmsg,
+ int num)
+{
+ int i, ret;
+ unsigned char swap;
+
+ /* Disable i2c */
+ writel(I2C_ENABLE_DISABLE, I2C_ENABLE);
+
+ /* Set the work mode and speed*/
+ writel(I2C_CON_MASTER | I2C_CON_SPEED_STD | I2C_CON_SLAVEDISABLE, I2C_CON);
+
+ writel(pmsg->addr, I2C_TAR);
+
+ /* Enable i2c */
+ writel(I2C_ENABLE_ENABLE, I2C_ENABLE);
+
+ dev_dbg(&adap->dev, "puv3_i2c_xfer: processing %d messages:\n", num);
+
+ for (i = 0; i < num; i++) {
+ dev_dbg(&adap->dev, " #%d: %sing %d byte%s %s 0x%02x\n", i,
+ pmsg->flags & I2C_M_RD ? "read" : "writ",
+ pmsg->len, pmsg->len > 1 ? "s" : "",
+ pmsg->flags & I2C_M_RD ? "from" : "to", pmsg->addr);
+
+ if (pmsg->len && pmsg->buf) { /* sanity check */
+ if (pmsg->flags & I2C_M_RD)
+ ret = xfer_read(adap, pmsg->buf, pmsg->len);
+ else
+ ret = xfer_write(adap, pmsg->buf, pmsg->len);
+
+ if (ret)
+ return ret;
+
+ }
+ dev_dbg(&adap->dev, "transfer complete\n");
+ pmsg++; /* next message */
+ }
+
+ /* XXX: fixup be16_to_cpu in bq27x00_battery.c */
+ if (pmsg->addr == I2C_TAR_PWIC) {
+ swap = pmsg->buf[0];
+ pmsg->buf[0] = pmsg->buf[1];
+ pmsg->buf[1] = swap;
+ }
+
+ return i;
+}
+
+/*
+ * Return list of supported functionality.
+ */
+static u32 puv3_i2c_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm puv3_i2c_algorithm = {
+ .master_xfer = puv3_i2c_xfer,
+ .functionality = puv3_i2c_func,
+};
+
+/*
+ * Main initialization routine.
+ */
+static int puv3_i2c_probe(struct platform_device *pdev)
+{
+ struct i2c_adapter *adapter;
+ struct resource *mem;
+ int rc;
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!mem)
+ return -ENODEV;
+
+ if (!request_mem_region(mem->start, resource_size(mem), "puv3_i2c"))
+ return -EBUSY;
+
+ adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
+ if (adapter == NULL) {
+ dev_err(&pdev->dev, "can't allocate interface!\n");
+ rc = -ENOMEM;
+ goto fail_nomem;
+ }
+ snprintf(adapter->name, sizeof(adapter->name), "PUV3-I2C at 0x%08x",
+ mem->start);
+ adapter->algo = &puv3_i2c_algorithm;
+ adapter->class = I2C_CLASS_HWMON;
+ adapter->dev.parent = &pdev->dev;
+
+ platform_set_drvdata(pdev, adapter);
+
+ adapter->nr = pdev->id;
+ rc = i2c_add_numbered_adapter(adapter);
+ if (rc) {
+ dev_err(&pdev->dev, "Adapter '%s' registration failed\n",
+ adapter->name);
+ goto fail_add_adapter;
+ }
+
+ dev_info(&pdev->dev, "PKUnity v3 i2c bus adapter.\n");
+ return 0;
+
+fail_add_adapter:
+ kfree(adapter);
+fail_nomem:
+ release_mem_region(mem->start, resource_size(mem));
+
+ return rc;
+}
+
+static int puv3_i2c_remove(struct platform_device *pdev)
+{
+ struct i2c_adapter *adapter = platform_get_drvdata(pdev);
+ struct resource *mem;
+
+ i2c_del_adapter(adapter);
+
+ put_device(&pdev->dev);
+
+ mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ release_mem_region(mem->start, resource_size(mem));
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int puv3_i2c_suspend(struct device *dev)
+{
+ int poll_count;
+ /* Disable the IIC */
+ writel(I2C_ENABLE_DISABLE, I2C_ENABLE);
+ for (poll_count = 0; poll_count < 50; poll_count++) {
+ if (readl(I2C_ENSTATUS) & I2C_ENSTATUS_ENABLE)
+ udelay(25);
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(puv3_i2c_pm, puv3_i2c_suspend, NULL);
+#define PUV3_I2C_PM (&puv3_i2c_pm)
+
+#else
+#define PUV3_I2C_PM NULL
+#endif
+
+static struct platform_driver puv3_i2c_driver = {
+ .probe = puv3_i2c_probe,
+ .remove = puv3_i2c_remove,
+ .driver = {
+ .name = "PKUnity-v3-I2C",
+ .pm = PUV3_I2C_PM,
+ }
+};
+
+module_platform_driver(puv3_i2c_driver);
+
+MODULE_DESCRIPTION("PKUnity v3 I2C driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:puv3_i2c");
Code Review / kvmfornfv.git / blobdiff