279 lines
6.6 KiB
C
279 lines
6.6 KiB
C
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// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* IBM OPAL I2C driver
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* Copyright (C) 2014 IBM
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*/
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#include <linux/device.h>
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#include <linux/i2c.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <asm/firmware.h>
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#include <asm/opal.h>
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static int i2c_opal_translate_error(int rc)
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{
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switch (rc) {
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case OPAL_NO_MEM:
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return -ENOMEM;
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case OPAL_PARAMETER:
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return -EINVAL;
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case OPAL_I2C_ARBT_LOST:
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return -EAGAIN;
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case OPAL_I2C_TIMEOUT:
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return -ETIMEDOUT;
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case OPAL_I2C_NACK_RCVD:
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return -ENXIO;
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case OPAL_I2C_STOP_ERR:
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return -EBUSY;
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default:
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return -EIO;
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}
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}
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static int i2c_opal_send_request(u32 bus_id, struct opal_i2c_request *req)
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{
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struct opal_msg msg;
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int token, rc;
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token = opal_async_get_token_interruptible();
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if (token < 0) {
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if (token != -ERESTARTSYS)
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pr_err("Failed to get the async token\n");
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return token;
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}
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rc = opal_i2c_request(token, bus_id, req);
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if (rc != OPAL_ASYNC_COMPLETION) {
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rc = i2c_opal_translate_error(rc);
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goto exit;
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}
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rc = opal_async_wait_response(token, &msg);
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if (rc)
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goto exit;
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rc = opal_get_async_rc(msg);
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if (rc != OPAL_SUCCESS) {
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rc = i2c_opal_translate_error(rc);
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goto exit;
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}
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exit:
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opal_async_release_token(token);
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return rc;
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}
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static int i2c_opal_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
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int num)
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{
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unsigned long opal_id = (unsigned long)adap->algo_data;
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struct opal_i2c_request req;
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int rc, i;
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/* We only support fairly simple combinations here of one
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* or two messages
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*/
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memset(&req, 0, sizeof(req));
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switch(num) {
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case 1:
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req.type = (msgs[0].flags & I2C_M_RD) ?
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OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
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req.addr = cpu_to_be16(msgs[0].addr);
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req.size = cpu_to_be32(msgs[0].len);
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req.buffer_ra = cpu_to_be64(__pa(msgs[0].buf));
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break;
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case 2:
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req.type = (msgs[1].flags & I2C_M_RD) ?
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OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
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req.addr = cpu_to_be16(msgs[0].addr);
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req.subaddr_sz = msgs[0].len;
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for (i = 0; i < msgs[0].len; i++)
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req.subaddr = (req.subaddr << 8) | msgs[0].buf[i];
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req.subaddr = cpu_to_be32(req.subaddr);
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req.size = cpu_to_be32(msgs[1].len);
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req.buffer_ra = cpu_to_be64(__pa(msgs[1].buf));
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break;
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}
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rc = i2c_opal_send_request(opal_id, &req);
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if (rc)
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return rc;
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return num;
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}
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static int i2c_opal_smbus_xfer(struct i2c_adapter *adap, u16 addr,
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unsigned short flags, char read_write,
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u8 command, int size, union i2c_smbus_data *data)
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{
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unsigned long opal_id = (unsigned long)adap->algo_data;
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struct opal_i2c_request req;
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u8 local[2];
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int rc;
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memset(&req, 0, sizeof(req));
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req.addr = cpu_to_be16(addr);
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switch (size) {
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case I2C_SMBUS_BYTE:
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req.buffer_ra = cpu_to_be64(__pa(&data->byte));
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req.size = cpu_to_be32(1);
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fallthrough;
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case I2C_SMBUS_QUICK:
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req.type = (read_write == I2C_SMBUS_READ) ?
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OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
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break;
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case I2C_SMBUS_BYTE_DATA:
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req.buffer_ra = cpu_to_be64(__pa(&data->byte));
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req.size = cpu_to_be32(1);
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req.subaddr = cpu_to_be32(command);
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req.subaddr_sz = 1;
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req.type = (read_write == I2C_SMBUS_READ) ?
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OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
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break;
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case I2C_SMBUS_WORD_DATA:
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if (!read_write) {
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local[0] = data->word & 0xff;
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local[1] = (data->word >> 8) & 0xff;
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}
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req.buffer_ra = cpu_to_be64(__pa(local));
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req.size = cpu_to_be32(2);
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req.subaddr = cpu_to_be32(command);
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req.subaddr_sz = 1;
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req.type = (read_write == I2C_SMBUS_READ) ?
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OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
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break;
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case I2C_SMBUS_I2C_BLOCK_DATA:
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req.buffer_ra = cpu_to_be64(__pa(&data->block[1]));
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req.size = cpu_to_be32(data->block[0]);
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req.subaddr = cpu_to_be32(command);
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req.subaddr_sz = 1;
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req.type = (read_write == I2C_SMBUS_READ) ?
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OPAL_I2C_SM_READ : OPAL_I2C_SM_WRITE;
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break;
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default:
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return -EINVAL;
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}
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rc = i2c_opal_send_request(opal_id, &req);
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if (!rc && read_write && size == I2C_SMBUS_WORD_DATA) {
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data->word = ((u16)local[1]) << 8;
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data->word |= local[0];
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}
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return rc;
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}
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static u32 i2c_opal_func(struct i2c_adapter *adapter)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
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I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
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I2C_FUNC_SMBUS_I2C_BLOCK;
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}
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static const struct i2c_algorithm i2c_opal_algo = {
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.master_xfer = i2c_opal_master_xfer,
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.smbus_xfer = i2c_opal_smbus_xfer,
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.functionality = i2c_opal_func,
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};
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/*
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* For two messages, we basically support simple smbus transactions of a
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* write-then-anything.
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*/
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static const struct i2c_adapter_quirks i2c_opal_quirks = {
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.flags = I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_SAME_ADDR,
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.max_comb_1st_msg_len = 4,
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};
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static int i2c_opal_probe(struct platform_device *pdev)
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{
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struct i2c_adapter *adapter;
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const char *pname;
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u32 opal_id;
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int rc;
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if (!pdev->dev.of_node)
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return -ENODEV;
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rc = of_property_read_u32(pdev->dev.of_node, "ibm,opal-id", &opal_id);
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if (rc) {
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dev_err(&pdev->dev, "Missing ibm,opal-id property !\n");
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return -EIO;
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}
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adapter = devm_kzalloc(&pdev->dev, sizeof(*adapter), GFP_KERNEL);
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if (!adapter)
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return -ENOMEM;
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adapter->algo = &i2c_opal_algo;
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adapter->algo_data = (void *)(unsigned long)opal_id;
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adapter->quirks = &i2c_opal_quirks;
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adapter->dev.parent = &pdev->dev;
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adapter->dev.of_node = of_node_get(pdev->dev.of_node);
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pname = of_get_property(pdev->dev.of_node, "ibm,port-name", NULL);
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if (pname)
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strscpy(adapter->name, pname, sizeof(adapter->name));
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else
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strscpy(adapter->name, "opal", sizeof(adapter->name));
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platform_set_drvdata(pdev, adapter);
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rc = i2c_add_adapter(adapter);
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if (rc)
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dev_err(&pdev->dev, "Failed to register the i2c adapter\n");
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return rc;
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}
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static int i2c_opal_remove(struct platform_device *pdev)
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{
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struct i2c_adapter *adapter = platform_get_drvdata(pdev);
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i2c_del_adapter(adapter);
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return 0;
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}
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static const struct of_device_id i2c_opal_of_match[] = {
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{
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.compatible = "ibm,opal-i2c",
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},
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{ }
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};
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MODULE_DEVICE_TABLE(of, i2c_opal_of_match);
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static struct platform_driver i2c_opal_driver = {
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.probe = i2c_opal_probe,
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.remove = i2c_opal_remove,
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.driver = {
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.name = "i2c-opal",
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.of_match_table = i2c_opal_of_match,
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},
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};
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static int __init i2c_opal_init(void)
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{
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if (!firmware_has_feature(FW_FEATURE_OPAL))
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return -ENODEV;
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return platform_driver_register(&i2c_opal_driver);
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}
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module_init(i2c_opal_init);
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static void __exit i2c_opal_exit(void)
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{
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return platform_driver_unregister(&i2c_opal_driver);
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}
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module_exit(i2c_opal_exit);
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MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
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MODULE_DESCRIPTION("IBM OPAL I2C driver");
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MODULE_LICENSE("GPL");
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