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260 lines
6.0 KiB
260 lines
6.0 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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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#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 const 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 <[email protected]>"); |
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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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