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278 lines
6.6 KiB
278 lines
6.6 KiB
// 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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strlcpy(adapter->name, pname, sizeof(adapter->name)); |
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else |
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strlcpy(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 <[email protected]>"); |
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MODULE_DESCRIPTION("IBM OPAL I2C driver"); |
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MODULE_LICENSE("GPL");
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