drivers/i2c/busses/i2c-opal.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * IBM OPAL I2C driver
  * Copyright (C) 2014 IBM
  */

 #include <linux/device.h>
 #include <linux/i2c.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>

 #include <asm/firmware.h>
 #include <asm/opal.h>

 static int i2c_opal_translate_error(int rc)
 {
 	switch (rc) {
 	case OPAL_NO_MEM:
 		return -ENOMEM;
 	case OPAL_PARAMETER:
 		return -EINVAL;
 	case OPAL_I2C_ARBT_LOST:
 		return -EAGAIN;
 	case OPAL_I2C_TIMEOUT:
 		return -ETIMEDOUT;
 	case OPAL_I2C_NACK_RCVD:
 		return -ENXIO;
 	case OPAL_I2C_STOP_ERR:
 		return -EBUSY;
 	default:
 		return -EIO;
 	}
 }

 static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
 {
 	struct opal_msg msg;
 	int token, rc;

 	token = opal_async_get_token_interruptible();
 	if (token < 0) {
 		if (token != -ERESTARTSYS)
 			pr_err("Failed to get the async token\n");

 		return token;
 	}

 	rc = opal_i2c_request(token, bus_id, req);
 	if (rc != OPAL_ASYNC_COMPLETION) {
 		rc = i2c_opal_translate_error(rc);
 		goto exit;
 	}

 	rc = opal_async_wait_response(token, &msg);
 	if (rc)
 		goto exit;

 	rc = opal_get_async_rc(msg);
 	if (rc != OPAL_SUCCESS) {
 		rc = i2c_opal_translate_error(rc);
 		goto exit;
 	}

 exit:
 	opal_async_release_token(token);
 	return rc;
 }

 static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 				int num)
 {
 	unsigned long opal_id = (unsigned long)adap->algo_data;
 	struct opal_i2c_request req;
 	int rc, i;

 	/* We only support fairly simple combinations here of one
 	 * or two messages
 	 */
 	memset(&req, 0, sizeof(req));
 	switch(num) {
 	case 1:
 		req.type = (msgs[0].flags & I2C_M_RD) ?
 			OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
 		req.addr = cpu_to_be16(msgs[0].addr);
 		req.size = cpu_to_be32(msgs[0].len);
 		req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf));
 		break;
 	case 2:
 		req.type = (msgs[1].flags & I2C_M_RD) ?
 			OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
 		req.addr = cpu_to_be16(msgs[0].addr);
 		req.subaddr_sz = msgs[0].len;
 		for (i = 0; i < msgs[0].len; i++)
 			req.subaddr = (req.subaddr << 8) | msgs[0].buf[i];
 		req.subaddr = cpu_to_be32(req.subaddr);
 		req.size = cpu_to_be32(msgs[1].len);
 		req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
 		break;
 	}

 	rc = i2c_opal_send_request(opal_id, &req);
 	if (rc)
 		return rc;

 	return num;
 }

 static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
 			       unsigned short flags, char read_write,
 			       u8 command, int size, union i2c_smbus_data *data)
 {
 	unsigned long opal_id = (unsigned long)adap->algo_data;
 	struct opal_i2c_request req;
 	u8 local[2];
 	int rc;

 	memset(&req, 0, sizeof(req));

 	req.addr = cpu_to_be16(addr);
 	switch (size) {
 	case I2C_SMBUS_BYTE:
 		req.buffer_ra = cpu_to_be64(__pa(&data->byte));
 		req.size = cpu_to_be32(1);
 		fallthrough;
 	case I2C_SMBUS_QUICK:
 		req.type = (read_write == I2C_SMBUS_READ) ?
 			OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
 		break;
 	case I2C_SMBUS_BYTE_DATA:
 		req.buffer_ra = cpu_to_be64(__pa(&data->byte));
 		req.size = cpu_to_be32(1);
 		req.subaddr = cpu_to_be32(command);
 		req.subaddr_sz = 1;
 		req.type = (read_write == I2C_SMBUS_READ) ?
 			OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
 		break;
 	case I2C_SMBUS_WORD_DATA:
 		if (!read_write) {
 			local[0] = data->word & 0xff;
 			local[1] = (data->word >> 8) & 0xff;
 		}
 		req.buffer_ra = cpu_to_be64(__pa(local));
 		req.size = cpu_to_be32(2);
 		req.subaddr = cpu_to_be32(command);
 		req.subaddr_sz = 1;
 		req.type = (read_write == I2C_SMBUS_READ) ?
 			OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
 		req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
 		req.size = cpu_to_be32(data->block[0]);
 		req.subaddr = cpu_to_be32(command);
 		req.subaddr_sz = 1;
 		req.type = (read_write == I2C_SMBUS_READ) ?
 			OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
 		break;
 	default:
 		return -EINVAL;
 	}

 	rc = i2c_opal_send_request(opal_id, &req);
 	if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
 		data->word = ((u16)local[1]) << 8;
 		data->word |= local[0];
 	}

 	return rc;
 }

 static u32 i2c_opal_func(struct i2c_adapter *adapter)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
 	       I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
 	       I2C_FUNC_SMBUS_I2C_BLOCK;
 }

 static const struct i2c_algorithm i2c_opal_algo = {
 	.master_xfer	= i2c_opal_master_xfer,
 	.smbus_xfer	= i2c_opal_smbus_xfer,
 	.functionality	= i2c_opal_func,
 };

 /*
  * For two messages, we basically support simple smbus transactions of a
  * write-then-anything.
  */
 static const struct i2c_adapter_quirks i2c_opal_quirks = {
 	.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
 	.max_comb_1st_msg_len = 4,
 };

 static int i2c_opal_probe(struct platform_device *pdev)
 {
 	struct i2c_adapter	*adapter;
 	const char		*pname;
 	u32			opal_id;
 	int			rc;

 	if (!pdev->dev.of_node)
 		return -ENODEV;

 	rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
 	if (rc) {
 		dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
 		return -EIO;
 	}

 	adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
 	if (!adapter)
 		return -ENOMEM;

 	adapter->algo = &i2c_opal_algo;
 	adapter->algo_data = (void *)(unsigned long)opal_id;
 	adapter->quirks = &i2c_opal_quirks;
 	adapter->dev.parent = &pdev->dev;
 	adapter->dev.of_node = of_node_get(pdev->dev.of_node);
 	pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL);
 	if (pname)
 		strscpy(adapter->name, pname, sizeof(adapter->name));
 	else
 		strscpy(adapter->name, "opal", sizeof(adapter->name));

 	platform_set_drvdata(pdev, adapter);
 	rc = i2c_add_adapter(adapter);
 	if (rc)
 		dev_err(&pdev->dev, "Failed to register the i2c adapter\n");

 	return rc;
 }

 static int i2c_opal_remove(struct platform_device *pdev)
 {
 	struct i2c_adapter *adapter = platform_get_drvdata(pdev);

 	i2c_del_adapter(adapter);

 	return 0;
 }

 static const struct of_device_id i2c_opal_of_match[] = {
 	{
 		.compatible = "ibm,opal-i2c",
 	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, i2c_opal_of_match);

 static struct platform_driver i2c_opal_driver = {
 	.probe	= i2c_opal_probe,
 	.remove	= i2c_opal_remove,
 	.driver	= {
 		.name		= "i2c-opal",
 		.of_match_table	= i2c_opal_of_match,
 	},
 };

 static int __init i2c_opal_init(void)
 {
 	if (!firmware_has_feature(FW_FEATURE_OPAL))
 		return -ENODEV;

 	return platform_driver_register(&i2c_opal_driver);
 }
 module_init(i2c_opal_init);

 static void __exit i2c_opal_exit(void)
 {
 	return platform_driver_unregister(&i2c_opal_driver);
 }
 module_exit(i2c_opal_exit);

 MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
 MODULE_DESCRIPTION("IBM OPAL I2C driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* IBM OPAL I2C driver
	* Copyright (C) 2014 IBM
	*/

	#include <linux/device.h>
	#include <linux/i2c.h>
	#include <linux/kernel.h>
	#include <linux/mm.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/platform_device.h>
	#include <linux/slab.h>

	#include <asm/firmware.h>
	#include <asm/opal.h>

	static int i2c_opal_translate_error(int rc)
	{
	switch (rc) {
	case OPAL_NO_MEM:
	return -ENOMEM;
	case OPAL_PARAMETER:
	return -EINVAL;
	case OPAL_I2C_ARBT_LOST:
	return -EAGAIN;
	case OPAL_I2C_TIMEOUT:
	return -ETIMEDOUT;
	case OPAL_I2C_NACK_RCVD:
	return -ENXIO;
	case OPAL_I2C_STOP_ERR:
	return -EBUSY;
	default:
	return -EIO;
	}
	}

	static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
	{
	struct opal_msg msg;
	int token, rc;

	token = opal_async_get_token_interruptible();
	if (token < 0) {
	if (token != -ERESTARTSYS)
	pr_err("Failed to get the async token\n");

	return token;
	}

	rc = opal_i2c_request(token, bus_id, req);
	if (rc != OPAL_ASYNC_COMPLETION) {
	rc = i2c_opal_translate_error(rc);
	goto exit;
	}

	rc = opal_async_wait_response(token, &msg);
	if (rc)
	goto exit;

	rc = opal_get_async_rc(msg);
	if (rc != OPAL_SUCCESS) {
	rc = i2c_opal_translate_error(rc);
	goto exit;
	}

	exit:
	opal_async_release_token(token);
	return rc;
	}

	static int i2c_opal_master_xfer(struct i2c_adapter adap, struct i2c_msg msgs,
	int num)
	{
	unsigned long opal_id = (unsigned long)adap->algo_data;
	struct opal_i2c_request req;
	int rc, i;

	/* We only support fairly simple combinations here of one
	* or two messages
	*/
	memset(&req, 0, sizeof(req));
	switch(num) {
	case 1:
	req.type = (msgs[0].flags & I2C_M_RD) ?
	OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
	req.addr = cpu_to_be16(msgs[0].addr);
	req.size = cpu_to_be32(msgs[0].len);
	req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf));
	break;
	case 2:
	req.type = (msgs[1].flags & I2C_M_RD) ?
	OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
	req.addr = cpu_to_be16(msgs[0].addr);
	req.subaddr_sz = msgs[0].len;
	for (i = 0; i < msgs[0].len; i++)
	req.subaddr = (req.subaddr << 8) \| msgs[0].buf[i];
	req.subaddr = cpu_to_be32(req.subaddr);
	req.size = cpu_to_be32(msgs[1].len);
	req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
	break;
	}

	rc = i2c_opal_send_request(opal_id, &req);
	if (rc)
	return rc;

	return num;
	}

	static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
	unsigned short flags, char read_write,
	u8 command, int size, union i2c_smbus_data *data)
	{
	unsigned long opal_id = (unsigned long)adap->algo_data;
	struct opal_i2c_request req;
	u8 local[2];
	int rc;

	memset(&req, 0, sizeof(req));

	req.addr = cpu_to_be16(addr);
	switch (size) {
	case I2C_SMBUS_BYTE:
	req.buffer_ra = cpu_to_be64(__pa(&data->byte));
	req.size = cpu_to_be32(1);
	fallthrough;
	case I2C_SMBUS_QUICK:
	req.type = (read_write == I2C_SMBUS_READ) ?
	OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
	break;
	case I2C_SMBUS_BYTE_DATA:
	req.buffer_ra = cpu_to_be64(__pa(&data->byte));
	req.size = cpu_to_be32(1);
	req.subaddr = cpu_to_be32(command);
	req.subaddr_sz = 1;
	req.type = (read_write == I2C_SMBUS_READ) ?
	OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
	break;
	case I2C_SMBUS_WORD_DATA:
	if (!read_write) {
	local[0] = data->word & 0xff;
	local[1] = (data->word >> 8) & 0xff;
	}
	req.buffer_ra = cpu_to_be64(__pa(local));
	req.size = cpu_to_be32(2);
	req.subaddr = cpu_to_be32(command);
	req.subaddr_sz = 1;
	req.type = (read_write == I2C_SMBUS_READ) ?
	OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
	break;
	case I2C_SMBUS_I2C_BLOCK_DATA:
	req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
	req.size = cpu_to_be32(data->block[0]);
	req.subaddr = cpu_to_be32(command);
	req.subaddr_sz = 1;
	req.type = (read_write == I2C_SMBUS_READ) ?
	OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
	break;
	default:
	return -EINVAL;
	}

	rc = i2c_opal_send_request(opal_id, &req);
	if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
	data->word = ((u16)local[1]) << 8;
	data->word \|= local[0];
	}

	return rc;
	}

	static u32 i2c_opal_func(struct i2c_adapter *adapter)
	{
	return I2C_FUNC_I2C \| I2C_FUNC_SMBUS_QUICK \| I2C_FUNC_SMBUS_BYTE \|
	I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_WORD_DATA \|
	I2C_FUNC_SMBUS_I2C_BLOCK;
	}

	static const struct i2c_algorithm i2c_opal_algo = {
	.master_xfer = i2c_opal_master_xfer,
	.smbus_xfer = i2c_opal_smbus_xfer,
	.functionality = i2c_opal_func,
	};

	/*
	* For two messages, we basically support simple smbus transactions of a
	* write-then-anything.
	*/
	static const struct i2c_adapter_quirks i2c_opal_quirks = {
	.flags = I2C_AQ_COMB \| I2C_AQ_COMB_WRITE_FIRST \| I2C_AQ_COMB_SAME_ADDR,
	.max_comb_1st_msg_len = 4,
	};

	static int i2c_opal_probe(struct platform_device *pdev)
	{
	struct i2c_adapter *adapter;
	const char *pname;
	u32 opal_id;
	int rc;

	if (!pdev->dev.of_node)
	return -ENODEV;

	rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
	if (rc) {
	dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
	return -EIO;
	}

	adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
	if (!adapter)
	return -ENOMEM;

	adapter->algo = &i2c_opal_algo;
	adapter->algo_data = (void *)(unsigned long)opal_id;
	adapter->quirks = &i2c_opal_quirks;
	adapter->dev.parent = &pdev->dev;
	adapter->dev.of_node = of_node_get(pdev->dev.of_node);
	pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL);
	if (pname)
	strscpy(adapter->name, pname, sizeof(adapter->name));
	else
	strscpy(adapter->name, "opal", sizeof(adapter->name));

	platform_set_drvdata(pdev, adapter);
	rc = i2c_add_adapter(adapter);
	if (rc)
	dev_err(&pdev->dev, "Failed to register the i2c adapter\n");

	return rc;
	}

	static int i2c_opal_remove(struct platform_device *pdev)
	{
	struct i2c_adapter *adapter = platform_get_drvdata(pdev);

	i2c_del_adapter(adapter);

	return 0;
	}

	static const struct of_device_id i2c_opal_of_match[] = {
	{
	.compatible = "ibm,opal-i2c",
	},
	{ }
	};
	MODULE_DEVICE_TABLE(of, i2c_opal_of_match);

	static struct platform_driver i2c_opal_driver = {
	.probe = i2c_opal_probe,
	.remove = i2c_opal_remove,
	.driver = {
	.name = "i2c-opal",
	.of_match_table = i2c_opal_of_match,
	},
	};

	static int __init i2c_opal_init(void)
	{
	if (!firmware_has_feature(FW_FEATURE_OPAL))
	return -ENODEV;

	return platform_driver_register(&i2c_opal_driver);
	}
	module_init(i2c_opal_init);

	static void __exit i2c_opal_exit(void)
	{
	return platform_driver_unregister(&i2c_opal_driver);
	}
	module_exit(i2c_opal_exit);

	MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
	MODULE_DESCRIPTION("IBM OPAL I2C driver");
	MODULE_LICENSE("GPL");