+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * Copyright (C) 1998, 1999 Frodo Looijaard <frodol@dds.nl> and
- * Philip Edelbrock <phil@netroedge.com>
- * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
- * Copyright (C) 2003 IBM Corp.
- * Copyright (C) 2004 Jean Delvare <jdelvare@suse.de>
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/capability.h>
-#include <linux/jiffies.h>
-#include <linux/i2c.h>
-#include <linux/mutex.h>
-
-/* Addresses to scan */
-static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54,
- 0x55, 0x56, 0x57, I2C_CLIENT_END };
-
-
-/* Size of EEPROM in bytes */
-#define EEPROM_SIZE 256
-
-/* possible types of eeprom devices */
-enum eeprom_nature {
- UNKNOWN,
- VAIO,
-};
-
-/* Each client has this additional data */
-struct eeprom_data {
- struct mutex update_lock;
- u8 valid; /* bitfield, bit!=0 if slice is valid */
- unsigned long last_updated[8]; /* In jiffies, 8 slices */
- u8 data[EEPROM_SIZE]; /* Register values */
- enum eeprom_nature nature;
-};
-
-
-static void eeprom_update_client(struct i2c_client *client, u8 slice)
-{
- struct eeprom_data *data = i2c_get_clientdata(client);
- int i;
-
- mutex_lock(&data->update_lock);
-
- if (!(data->valid & (1 << slice)) ||
- time_after(jiffies, data->last_updated[slice] + 300 * HZ)) {
- dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice);
-
- if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
- for (i = slice << 5; i < (slice + 1) << 5; i += 32)
- if (i2c_smbus_read_i2c_block_data(client, i,
- 32, data->data + i)
- != 32)
- goto exit;
- } else {
- for (i = slice << 5; i < (slice + 1) << 5; i += 2) {
- int word = i2c_smbus_read_word_data(client, i);
- if (word < 0)
- goto exit;
- data->data[i] = word & 0xff;
- data->data[i + 1] = word >> 8;
- }
- }
- data->last_updated[slice] = jiffies;
- data->valid |= (1 << slice);
- }
-exit:
- mutex_unlock(&data->update_lock);
-}
-
-static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
- struct bin_attribute *bin_attr,
- char *buf, loff_t off, size_t count)
-{
- struct i2c_client *client = kobj_to_i2c_client(kobj);
- struct eeprom_data *data = i2c_get_clientdata(client);
- u8 slice;
-
- /* Only refresh slices which contain requested bytes */
- for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++)
- eeprom_update_client(client, slice);
-
- /* Hide Vaio private settings to regular users:
- - BIOS passwords: bytes 0x00 to 0x0f
- - UUID: bytes 0x10 to 0x1f
- - Serial number: 0xc0 to 0xdf */
- if (data->nature == VAIO && !capable(CAP_SYS_ADMIN)) {
- int i;
-
- for (i = 0; i < count; i++) {
- if ((off + i <= 0x1f) ||
- (off + i >= 0xc0 && off + i <= 0xdf))
- buf[i] = 0;
- else
- buf[i] = data->data[off + i];
- }
- } else {
- memcpy(buf, &data->data[off], count);
- }
-
- return count;
-}
-
-static const struct bin_attribute eeprom_attr = {
- .attr = {
- .name = "eeprom",
- .mode = S_IRUGO,
- },
- .size = EEPROM_SIZE,
- .read = eeprom_read,
-};
-
-/* Return 0 if detection is successful, -ENODEV otherwise */
-static int eeprom_detect(struct i2c_client *client, struct i2c_board_info *info)
-{
- struct i2c_adapter *adapter = client->adapter;
-
- /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all
- addresses 0x50-0x57, but we only care about 0x50. So decline
- attaching to addresses >= 0x51 on DDC buses */
- if (!(adapter->class & I2C_CLASS_SPD) && client->addr >= 0x51)
- return -ENODEV;
-
- /* There are four ways we can read the EEPROM data:
- (1) I2C block reads (faster, but unsupported by most adapters)
- (2) Word reads (128% overhead)
- (3) Consecutive byte reads (88% overhead, unsafe)
- (4) Regular byte data reads (265% overhead)
- The third and fourth methods are not implemented by this driver
- because all known adapters support one of the first two. */
- if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)
- && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
- return -ENODEV;
-
- strscpy(info->type, "eeprom", I2C_NAME_SIZE);
-
- return 0;
-}
-
-static int eeprom_probe(struct i2c_client *client)
-{
- struct i2c_adapter *adapter = client->adapter;
- struct eeprom_data *data;
-
- data = devm_kzalloc(&client->dev, sizeof(struct eeprom_data),
- GFP_KERNEL);
- if (!data)
- return -ENOMEM;
-
- memset(data->data, 0xff, EEPROM_SIZE);
- i2c_set_clientdata(client, data);
- mutex_init(&data->update_lock);
- data->nature = UNKNOWN;
-
- /* Detect the Vaio nature of EEPROMs.
- We use the "PCG-" or "VGN-" prefix as the signature. */
- if (client->addr == 0x57
- && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
- char name[4];
-
- name[0] = i2c_smbus_read_byte_data(client, 0x80);
- name[1] = i2c_smbus_read_byte_data(client, 0x81);
- name[2] = i2c_smbus_read_byte_data(client, 0x82);
- name[3] = i2c_smbus_read_byte_data(client, 0x83);
-
- if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
- dev_info(&client->dev, "Vaio EEPROM detected, "
- "enabling privacy protection\n");
- data->nature = VAIO;
- }
- }
-
- /* Let the users know they are using deprecated driver */
- dev_notice(&client->dev,
- "eeprom driver is deprecated, please use at24 instead\n");
-
- /* create the sysfs eeprom file */
- return sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr);
-}
-
-static void eeprom_remove(struct i2c_client *client)
-{
- sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
-}
-
-static const struct i2c_device_id eeprom_id[] = {
- { "eeprom", 0 },
- { }
-};
-
-static struct i2c_driver eeprom_driver = {
- .driver = {
- .name = "eeprom",
- },
- .probe = eeprom_probe,
- .remove = eeprom_remove,
- .id_table = eeprom_id,
-
- .class = I2C_CLASS_DDC | I2C_CLASS_SPD,
- .detect = eeprom_detect,
- .address_list = normal_i2c,
-};
-
-module_i2c_driver(eeprom_driver);
-
-MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
- "Philip Edelbrock <phil@netroedge.com> and "
- "Greg Kroah-Hartman <greg@kroah.com>");
-MODULE_DESCRIPTION("I2C EEPROM driver");
-MODULE_LICENSE("GPL");
git.samba.org / sfrench / cifs-2.6.git / commitdiff