drivers/i2c/busses/i2c-powermac.c - third_party/linux - Git at Google

 /*
     i2c Support for Apple SMU Controller

     Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
                        <benh@kernel.crashing.org>

     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.

     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.

     You should have received a copy of the GNU General Public License
     along with this program; if not, write to the Free Software
     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

 */

 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/device.h>
 #include <linux/platform_device.h>
 #include <asm/prom.h>
 #include <asm/pmac_low_i2c.h>

 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
 MODULE_LICENSE("GPL");

 /*
  * SMBUS-type transfer entrypoint
  */
 static s32 i2c_powermac_smbus_xfer(	struct i2c_adapter*	adap,
 					u16			addr,
 					unsigned short		flags,
 					char			read_write,
 					u8			command,
 					int			size,
 					union i2c_smbus_data*	data)
 {
 	struct pmac_i2c_bus	*bus = i2c_get_adapdata(adap);
 	int			rc = 0;
 	int			read = (read_write == I2C_SMBUS_READ);
 	int			addrdir = (addr << 1) | read;
 	u8			local[2];

 	rc = pmac_i2c_open(bus, 0);
 	if (rc)
 		return rc;

 	switch (size) {
         case I2C_SMBUS_QUICK:
 		rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 		if (rc)
 			goto bail;
 		rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0);
 	    	break;
         case I2C_SMBUS_BYTE:
 		rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 		if (rc)
 			goto bail;
 		rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1);
 	    	break;
         case I2C_SMBUS_BYTE_DATA:
 		rc = pmac_i2c_setmode(bus, read ?
 				      pmac_i2c_mode_combined :
 				      pmac_i2c_mode_stdsub);
 		if (rc)
 			goto bail;
 		rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1);
 	    	break;
         case I2C_SMBUS_WORD_DATA:
 		rc = pmac_i2c_setmode(bus, read ?
 				      pmac_i2c_mode_combined :
 				      pmac_i2c_mode_stdsub);
 		if (rc)
 			goto bail;
 		if (!read) {
 			local[0] = data->word & 0xff;
 			local[1] = (data->word >> 8) & 0xff;
 		}
 		rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2);
 		if (rc == 0 && read) {
 			data->word = ((u16)local[1]) << 8;
 			data->word |= local[0];
 		}
 	    	break;

 	/* Note that these are broken vs. the expected smbus API where
 	 * on reads, the length is actually returned from the function,
 	 * but I think the current API makes no sense and I don't want
 	 * any driver that I haven't verified for correctness to go
 	 * anywhere near a pmac i2c bus anyway ...
 	 *
 	 * I'm also not completely sure what kind of phases to do between
 	 * the actual command and the data (what I am _supposed_ to do that
 	 * is). For now, I assume writes are a single stream and reads have
 	 * a repeat start/addr phase (but not stop in between)
 	 */
         case I2C_SMBUS_BLOCK_DATA:
 		rc = pmac_i2c_setmode(bus, read ?
 				      pmac_i2c_mode_combined :
 				      pmac_i2c_mode_stdsub);
 		if (rc)
 			goto bail;
 		rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block,
 				   data->block[0] + 1);

 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
 		rc = pmac_i2c_setmode(bus, read ?
 				      pmac_i2c_mode_combined :
 				      pmac_i2c_mode_stdsub);
 		if (rc)
 			goto bail;
 		rc = pmac_i2c_xfer(bus, addrdir, 1, command,
 				   &data->block[1], data->block[0]);
 		break;

         default:
 	    	rc = -EINVAL;
 	}
  bail:
 	pmac_i2c_close(bus);
 	return rc;
 }

 /*
  * Generic i2c master transfer entrypoint. This driver only support single
  * messages (for "lame i2c" transfers). Anything else should use the smbus
  * entry point
  */
 static int i2c_powermac_master_xfer(	struct i2c_adapter *adap,
 					struct i2c_msg *msgs,
 					int num)
 {
 	struct pmac_i2c_bus	*bus = i2c_get_adapdata(adap);
 	int			rc = 0;
 	int			read;
 	int			addrdir;

 	if (msgs->flags & I2C_M_TEN)
 		return -EINVAL;
 	read = (msgs->flags & I2C_M_RD) != 0;
 	addrdir = (msgs->addr << 1) | read;
 	if (msgs->flags & I2C_M_REV_DIR_ADDR)
 		addrdir ^= 1;

 	rc = pmac_i2c_open(bus, 0);
 	if (rc)
 		return rc;
 	rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
 	if (rc)
 		goto bail;
 	rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
  bail:
 	pmac_i2c_close(bus);
 	return rc < 0 ? rc : 1;
 }

 static u32 i2c_powermac_func(struct i2c_adapter * adapter)
 {
 	return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 		I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 		I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C;
 }

 /* For now, we only handle smbus */
 static const struct i2c_algorithm i2c_powermac_algorithm = {
 	.smbus_xfer	= i2c_powermac_smbus_xfer,
 	.master_xfer	= i2c_powermac_master_xfer,
 	.functionality	= i2c_powermac_func,
 };


 static int i2c_powermac_remove(struct platform_device *dev)
 {
 	struct i2c_adapter	*adapter = platform_get_drvdata(dev);
 	struct pmac_i2c_bus	*bus = i2c_get_adapdata(adapter);
 	int			rc;

 	rc = i2c_del_adapter(adapter);
 	pmac_i2c_detach_adapter(bus, adapter);
 	i2c_set_adapdata(adapter, NULL);
 	/* We aren't that prepared to deal with this... */
 	if (rc)
 		printk("i2c-powermac.c: Failed to remove bus %s !\n",
 		       adapter->name);
 	platform_set_drvdata(dev, NULL);
 	kfree(adapter);

 	return 0;
 }


 static int __devexit i2c_powermac_probe(struct platform_device *dev)
 {
 	struct pmac_i2c_bus *bus = dev->dev.platform_data;
 	struct device_node *parent = NULL;
 	struct i2c_adapter *adapter;
 	char name[32];
 	const char *basename;
 	int rc;

 	if (bus == NULL)
 		return -EINVAL;

 	/* Ok, now we need to make up a name for the interface that will
 	 * match what we used to do in the past, that is basically the
 	 * controller's parent device node for keywest. PMU didn't have a
 	 * naming convention and SMU has a different one
 	 */
 	switch(pmac_i2c_get_type(bus)) {
 	case pmac_i2c_bus_keywest:
 		parent = of_get_parent(pmac_i2c_get_controller(bus));
 		if (parent == NULL)
 			return -EINVAL;
 		basename = parent->name;
 		break;
 	case pmac_i2c_bus_pmu:
 		basename = "pmu";
 		break;
 	case pmac_i2c_bus_smu:
 		/* This is not what we used to do but I'm fixing drivers at
 		 * the same time as this change
 		 */
 		basename = "smu";
 		break;
 	default:
 		return -EINVAL;
 	}
 	snprintf(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus));
 	of_node_put(parent);

 	adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
 	if (adapter == NULL) {
 		printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n");
 		return -ENOMEM;
 	}
 	platform_set_drvdata(dev, adapter);
 	strcpy(adapter->name, name);
 	adapter->algo = &i2c_powermac_algorithm;
 	i2c_set_adapdata(adapter, bus);
 	adapter->dev.parent = &dev->dev;
 	pmac_i2c_attach_adapter(bus, adapter);
 	rc = i2c_add_adapter(adapter);
 	if (rc) {
 		printk(KERN_ERR "i2c-powermac: Adapter %s registration "
 		       "failed\n", name);
 		i2c_set_adapdata(adapter, NULL);
 		pmac_i2c_detach_adapter(bus, adapter);
 	}

 	printk(KERN_INFO "PowerMac i2c bus %s registered\n", name);
 	return rc;
 }


 static struct platform_driver i2c_powermac_driver = {
 	.probe = i2c_powermac_probe,
 	.remove = __devexit_p(i2c_powermac_remove),
 	.driver = {
 		.name = "i2c-powermac",
 		.bus = &platform_bus_type,
 	},
 };

 static int __init i2c_powermac_init(void)
 {
 	platform_driver_register(&i2c_powermac_driver);
 	return 0;
 }


 static void __exit i2c_powermac_cleanup(void)
 {
 	platform_driver_unregister(&i2c_powermac_driver);
 }

 module_init(i2c_powermac_init);
 module_exit(i2c_powermac_cleanup);
	/*
	i2c Support for Apple SMU Controller

	Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
	<benh@kernel.crashing.org>

	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.

	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.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the Free Software
	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

	*/

	#include <linux/module.h>
	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/i2c.h>
	#include <linux/init.h>
	#include <linux/device.h>
	#include <linux/platform_device.h>
	#include <asm/prom.h>
	#include <asm/pmac_low_i2c.h>

	MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
	MODULE_LICENSE("GPL");

	/*
	* SMBUS-type transfer entrypoint
	*/
	static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap,
	u16 addr,
	unsigned short flags,
	char read_write,
	u8 command,
	int size,
	union i2c_smbus_data* data)
	{
	struct pmac_i2c_bus *bus = i2c_get_adapdata(adap);
	int rc = 0;
	int read = (read_write == I2C_SMBUS_READ);
	int addrdir = (addr << 1) \| read;
	u8 local[2];

	rc = pmac_i2c_open(bus, 0);
	if (rc)
	return rc;

	switch (size) {
	case I2C_SMBUS_QUICK:
	rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
	if (rc)
	goto bail;
	rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0);
	break;
	case I2C_SMBUS_BYTE:
	rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
	if (rc)
	goto bail;
	rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1);
	break;
	case I2C_SMBUS_BYTE_DATA:
	rc = pmac_i2c_setmode(bus, read ?
	pmac_i2c_mode_combined :
	pmac_i2c_mode_stdsub);
	if (rc)
	goto bail;
	rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1);
	break;
	case I2C_SMBUS_WORD_DATA:
	rc = pmac_i2c_setmode(bus, read ?
	pmac_i2c_mode_combined :
	pmac_i2c_mode_stdsub);
	if (rc)
	goto bail;
	if (!read) {
	local[0] = data->word & 0xff;
	local[1] = (data->word >> 8) & 0xff;
	}
	rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2);
	if (rc == 0 && read) {
	data->word = ((u16)local[1]) << 8;
	data->word \|= local[0];
	}
	break;

	/* Note that these are broken vs. the expected smbus API where
	* on reads, the length is actually returned from the function,
	* but I think the current API makes no sense and I don't want
	* any driver that I haven't verified for correctness to go
	* anywhere near a pmac i2c bus anyway ...
	*
	* I'm also not completely sure what kind of phases to do between
	* the actual command and the data (what I am _supposed_ to do that
	* is). For now, I assume writes are a single stream and reads have
	* a repeat start/addr phase (but not stop in between)
	*/
	case I2C_SMBUS_BLOCK_DATA:
	rc = pmac_i2c_setmode(bus, read ?
	pmac_i2c_mode_combined :
	pmac_i2c_mode_stdsub);
	if (rc)
	goto bail;
	rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block,
	data->block[0] + 1);

	break;
	case I2C_SMBUS_I2C_BLOCK_DATA:
	rc = pmac_i2c_setmode(bus, read ?
	pmac_i2c_mode_combined :
	pmac_i2c_mode_stdsub);
	if (rc)
	goto bail;
	rc = pmac_i2c_xfer(bus, addrdir, 1, command,
	&data->block[1], data->block[0]);
	break;

	default:
	rc = -EINVAL;
	}
	bail:
	pmac_i2c_close(bus);
	return rc;
	}

	/*
	* Generic i2c master transfer entrypoint. This driver only support single
	* messages (for "lame i2c" transfers). Anything else should use the smbus
	* entry point
	*/
	static int i2c_powermac_master_xfer( struct i2c_adapter *adap,
	struct i2c_msg *msgs,
	int num)
	{
	struct pmac_i2c_bus *bus = i2c_get_adapdata(adap);
	int rc = 0;
	int read;
	int addrdir;

	if (msgs->flags & I2C_M_TEN)
	return -EINVAL;
	read = (msgs->flags & I2C_M_RD) != 0;
	addrdir = (msgs->addr << 1) \| read;
	if (msgs->flags & I2C_M_REV_DIR_ADDR)
	addrdir ^= 1;

	rc = pmac_i2c_open(bus, 0);
	if (rc)
	return rc;
	rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
	if (rc)
	goto bail;
	rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
	bail:
	pmac_i2c_close(bus);
	return rc < 0 ? rc : 1;
	}

	static u32 i2c_powermac_func(struct i2c_adapter * adapter)
	{
	return I2C_FUNC_SMBUS_QUICK \| I2C_FUNC_SMBUS_BYTE \|
	I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_WORD_DATA \|
	I2C_FUNC_SMBUS_BLOCK_DATA \| I2C_FUNC_I2C;
	}

	/* For now, we only handle smbus */
	static const struct i2c_algorithm i2c_powermac_algorithm = {
	.smbus_xfer = i2c_powermac_smbus_xfer,
	.master_xfer = i2c_powermac_master_xfer,
	.functionality = i2c_powermac_func,
	};


	static int i2c_powermac_remove(struct platform_device *dev)
	{
	struct i2c_adapter *adapter = platform_get_drvdata(dev);
	struct pmac_i2c_bus *bus = i2c_get_adapdata(adapter);
	int rc;

	rc = i2c_del_adapter(adapter);
	pmac_i2c_detach_adapter(bus, adapter);
	i2c_set_adapdata(adapter, NULL);
	/* We aren't that prepared to deal with this... */
	if (rc)
	printk("i2c-powermac.c: Failed to remove bus %s !\n",
	adapter->name);
	platform_set_drvdata(dev, NULL);
	kfree(adapter);

	return 0;
	}


	static int __devexit i2c_powermac_probe(struct platform_device *dev)
	{
	struct pmac_i2c_bus *bus = dev->dev.platform_data;
	struct device_node *parent = NULL;
	struct i2c_adapter *adapter;
	char name[32];
	const char *basename;
	int rc;

	if (bus == NULL)
	return -EINVAL;

	/* Ok, now we need to make up a name for the interface that will
	* match what we used to do in the past, that is basically the
	* controller's parent device node for keywest. PMU didn't have a
	* naming convention and SMU has a different one
	*/
	switch(pmac_i2c_get_type(bus)) {
	case pmac_i2c_bus_keywest:
	parent = of_get_parent(pmac_i2c_get_controller(bus));
	if (parent == NULL)
	return -EINVAL;
	basename = parent->name;
	break;
	case pmac_i2c_bus_pmu:
	basename = "pmu";
	break;
	case pmac_i2c_bus_smu:
	/* This is not what we used to do but I'm fixing drivers at
	* the same time as this change
	*/
	basename = "smu";
	break;
	default:
	return -EINVAL;
	}
	snprintf(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus));
	of_node_put(parent);

	adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
	if (adapter == NULL) {
	printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n");
	return -ENOMEM;
	}
	platform_set_drvdata(dev, adapter);
	strcpy(adapter->name, name);
	adapter->algo = &i2c_powermac_algorithm;
	i2c_set_adapdata(adapter, bus);
	adapter->dev.parent = &dev->dev;
	pmac_i2c_attach_adapter(bus, adapter);
	rc = i2c_add_adapter(adapter);
	if (rc) {
	printk(KERN_ERR "i2c-powermac: Adapter %s registration "
	"failed\n", name);
	i2c_set_adapdata(adapter, NULL);
	pmac_i2c_detach_adapter(bus, adapter);
	}

	printk(KERN_INFO "PowerMac i2c bus %s registered\n", name);
	return rc;
	}


	static struct platform_driver i2c_powermac_driver = {
	.probe = i2c_powermac_probe,
	.remove = __devexit_p(i2c_powermac_remove),
	.driver = {
	.name = "i2c-powermac",
	.bus = &platform_bus_type,
	},
	};

	static int __init i2c_powermac_init(void)
	{
	platform_driver_register(&i2c_powermac_driver);
	return 0;
	}


	static void __exit i2c_powermac_cleanup(void)
	{
	platform_driver_unregister(&i2c_powermac_driver);
	}

	module_init(i2c_powermac_init);
	module_exit(i2c_powermac_cleanup);