drivers/i2c/busses/i2c-puv3.c - kernel/msm - Gitiles

 /*
  * 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/init.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 __devinit 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 inteface!\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:
 	platform_set_drvdata(pdev, NULL);
 	kfree(adapter);
 fail_nomem:
 	release_mem_region(mem->start, resource_size(mem));

 	return rc;
 }

 static int __devexit puv3_i2c_remove(struct platform_device *pdev)
 {
 	struct i2c_adapter *adapter = platform_get_drvdata(pdev);
 	struct resource *mem;
 	int rc;

 	rc = i2c_del_adapter(adapter);
 	if (rc) {
 		dev_err(&pdev->dev, "Adapter '%s' delete fail\n",
 				adapter->name);
 		return rc;
 	}

 	put_device(&pdev->dev);
 	platform_set_drvdata(pdev, NULL);

 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	release_mem_region(mem->start, resource_size(mem));

 	return rc;
 }

 #ifdef CONFIG_PM
 static int puv3_i2c_suspend(struct platform_device *dev, pm_message_t state)
 {
 	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 int puv3_i2c_resume(struct platform_device *dev)
 {
 	return 0 ;
 }
 #else
 #define puv3_i2c_suspend NULL
 #define puv3_i2c_resume NULL
 #endif

 static struct platform_driver puv3_i2c_driver = {
 	.probe		= puv3_i2c_probe,
 	.remove		= __devexit_p(puv3_i2c_remove),
 	.suspend	= puv3_i2c_suspend,
 	.resume		= puv3_i2c_resume,
 	.driver		= {
 		.name	= "PKUnity-v3-I2C",
 		.owner	= THIS_MODULE,
 	}
 };

 module_platform_driver(puv3_i2c_driver);

 MODULE_DESCRIPTION("PKUnity v3 I2C driver");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:puv3_i2c");
	/*
	* 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/init.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 __devinit 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 inteface!\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:
	platform_set_drvdata(pdev, NULL);
	kfree(adapter);
	fail_nomem:
	release_mem_region(mem->start, resource_size(mem));

	return rc;
	}

	static int __devexit puv3_i2c_remove(struct platform_device *pdev)
	{
	struct i2c_adapter *adapter = platform_get_drvdata(pdev);
	struct resource *mem;
	int rc;

	rc = i2c_del_adapter(adapter);
	if (rc) {
	dev_err(&pdev->dev, "Adapter '%s' delete fail\n",
	adapter->name);
	return rc;
	}

	put_device(&pdev->dev);
	platform_set_drvdata(pdev, NULL);

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(mem->start, resource_size(mem));

	return rc;
	}

	#ifdef CONFIG_PM
	static int puv3_i2c_suspend(struct platform_device *dev, pm_message_t state)
	{
	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 int puv3_i2c_resume(struct platform_device *dev)
	{
	return 0 ;
	}
	#else
	#define puv3_i2c_suspend NULL
	#define puv3_i2c_resume NULL
	#endif

	static struct platform_driver puv3_i2c_driver = {
	.probe = puv3_i2c_probe,
	.remove = __devexit_p(puv3_i2c_remove),
	.suspend = puv3_i2c_suspend,
	.resume = puv3_i2c_resume,
	.driver = {
	.name = "PKUnity-v3-I2C",
	.owner = THIS_MODULE,
	}
	};

	module_platform_driver(puv3_i2c_driver);

	MODULE_DESCRIPTION("PKUnity v3 I2C driver");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:puv3_i2c");