264 lines
6.2 KiB
C
264 lines
6.2 KiB
C
/*
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* Driver for the Diolan DLN-2 USB-I2C adapter
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*
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* Copyright (c) 2014 Intel Corporation
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*
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* Derived from:
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* i2c-diolan-u2c.c
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* Copyright (c) 2010-2011 Ericsson AB
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/platform_device.h>
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#include <linux/mfd/dln2.h>
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#include <linux/acpi.h>
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#define DLN2_I2C_MODULE_ID 0x03
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#define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID)
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/* I2C commands */
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#define DLN2_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00)
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#define DLN2_I2C_ENABLE DLN2_I2C_CMD(0x01)
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#define DLN2_I2C_DISABLE DLN2_I2C_CMD(0x02)
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#define DLN2_I2C_IS_ENABLED DLN2_I2C_CMD(0x03)
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#define DLN2_I2C_WRITE DLN2_I2C_CMD(0x06)
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#define DLN2_I2C_READ DLN2_I2C_CMD(0x07)
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#define DLN2_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08)
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#define DLN2_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09)
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#define DLN2_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A)
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#define DLN2_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B)
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#define DLN2_I2C_TRANSFER DLN2_I2C_CMD(0x0C)
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#define DLN2_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D)
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#define DLN2_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E)
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#define DLN2_I2C_MAX_XFER_SIZE 256
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#define DLN2_I2C_BUF_SIZE (DLN2_I2C_MAX_XFER_SIZE + 16)
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struct dln2_i2c {
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struct platform_device *pdev;
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struct i2c_adapter adapter;
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u8 port;
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/*
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* Buffer to hold the packet for read or write transfers. One is enough
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* since we can't have multiple transfers in parallel on the i2c bus.
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*/
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void *buf;
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};
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static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable)
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{
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u16 cmd;
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struct {
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u8 port;
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} tx;
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tx.port = dln2->port;
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if (enable)
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cmd = DLN2_I2C_ENABLE;
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else
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cmd = DLN2_I2C_DISABLE;
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return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));
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}
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static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr,
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u8 *data, u16 data_len)
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{
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int ret;
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struct {
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u8 port;
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u8 addr;
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u8 mem_addr_len;
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__le32 mem_addr;
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__le16 buf_len;
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u8 buf[DLN2_I2C_MAX_XFER_SIZE];
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} __packed *tx = dln2->buf;
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unsigned len;
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BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE);
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tx->port = dln2->port;
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tx->addr = addr;
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tx->mem_addr_len = 0;
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tx->mem_addr = 0;
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tx->buf_len = cpu_to_le16(data_len);
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memcpy(tx->buf, data, data_len);
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len = sizeof(*tx) + data_len - DLN2_I2C_MAX_XFER_SIZE;
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ret = dln2_transfer_tx(dln2->pdev, DLN2_I2C_WRITE, tx, len);
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if (ret < 0)
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return ret;
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return data_len;
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}
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static int dln2_i2c_read(struct dln2_i2c *dln2, u16 addr, u8 *data,
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u16 data_len)
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{
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int ret;
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struct {
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u8 port;
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u8 addr;
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u8 mem_addr_len;
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__le32 mem_addr;
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__le16 buf_len;
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} __packed tx;
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struct {
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__le16 buf_len;
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u8 buf[DLN2_I2C_MAX_XFER_SIZE];
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} __packed *rx = dln2->buf;
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unsigned rx_len = sizeof(*rx);
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BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE);
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tx.port = dln2->port;
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tx.addr = addr;
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tx.mem_addr_len = 0;
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tx.mem_addr = 0;
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tx.buf_len = cpu_to_le16(data_len);
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ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx),
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rx, &rx_len);
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if (ret < 0)
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return ret;
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if (rx_len < sizeof(rx->buf_len) + data_len)
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return -EPROTO;
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if (le16_to_cpu(rx->buf_len) != data_len)
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return -EPROTO;
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memcpy(data, rx->buf, data_len);
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return data_len;
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}
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static int dln2_i2c_xfer(struct i2c_adapter *adapter,
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struct i2c_msg *msgs, int num)
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{
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struct dln2_i2c *dln2 = i2c_get_adapdata(adapter);
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struct i2c_msg *pmsg;
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int i;
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for (i = 0; i < num; i++) {
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int ret;
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pmsg = &msgs[i];
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if (pmsg->flags & I2C_M_RD) {
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ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf,
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pmsg->len);
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if (ret < 0)
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return ret;
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pmsg->len = ret;
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} else {
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ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf,
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pmsg->len);
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if (ret != pmsg->len)
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return -EPROTO;
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}
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}
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return num;
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}
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static u32 dln2_i2c_func(struct i2c_adapter *a)
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{
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return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |
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I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
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I2C_FUNC_SMBUS_I2C_BLOCK;
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}
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static const struct i2c_algorithm dln2_i2c_usb_algorithm = {
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.master_xfer = dln2_i2c_xfer,
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.functionality = dln2_i2c_func,
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};
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static struct i2c_adapter_quirks dln2_i2c_quirks = {
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.max_read_len = DLN2_I2C_MAX_XFER_SIZE,
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.max_write_len = DLN2_I2C_MAX_XFER_SIZE,
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};
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static int dln2_i2c_probe(struct platform_device *pdev)
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{
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int ret;
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struct dln2_i2c *dln2;
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struct device *dev = &pdev->dev;
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struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev);
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dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL);
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if (!dln2)
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return -ENOMEM;
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dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL);
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if (!dln2->buf)
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return -ENOMEM;
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dln2->pdev = pdev;
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dln2->port = pdata->port;
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/* setup i2c adapter description */
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dln2->adapter.owner = THIS_MODULE;
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dln2->adapter.class = I2C_CLASS_HWMON;
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dln2->adapter.algo = &dln2_i2c_usb_algorithm;
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dln2->adapter.quirks = &dln2_i2c_quirks;
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dln2->adapter.dev.parent = dev;
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ACPI_COMPANION_SET(&dln2->adapter.dev, ACPI_COMPANION(&pdev->dev));
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dln2->adapter.dev.of_node = dev->of_node;
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i2c_set_adapdata(&dln2->adapter, dln2);
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snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d",
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"dln2-i2c", dev_name(pdev->dev.parent), dln2->port);
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platform_set_drvdata(pdev, dln2);
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/* initialize the i2c interface */
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ret = dln2_i2c_enable(dln2, true);
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if (ret < 0) {
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dev_err(dev, "failed to initialize adapter: %d\n", ret);
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return ret;
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}
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/* and finally attach to i2c layer */
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ret = i2c_add_adapter(&dln2->adapter);
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if (ret < 0)
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goto out_disable;
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return 0;
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out_disable:
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dln2_i2c_enable(dln2, false);
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return ret;
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}
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static int dln2_i2c_remove(struct platform_device *pdev)
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{
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struct dln2_i2c *dln2 = platform_get_drvdata(pdev);
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i2c_del_adapter(&dln2->adapter);
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dln2_i2c_enable(dln2, false);
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return 0;
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}
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static struct platform_driver dln2_i2c_driver = {
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.driver.name = "dln2-i2c",
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.probe = dln2_i2c_probe,
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.remove = dln2_i2c_remove,
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};
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module_platform_driver(dln2_i2c_driver);
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MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");
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MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:dln2-i2c");
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