From 5195e5093bb7d30dbf057b260005cb4ab9761168 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 26 Jan 2009 21:19:53 +0100 Subject: i2c: Move at24 to drivers/misc/eeprom As drivers/i2c/chips is going to go away, move the driver to drivers/misc/eeprom. Other eeprom drivers may be moved here later, too. Update Kconfig text to specify this driver as I2C. Signed-off-by: Wolfram Sang Signed-off-by: Jean Delvare --- drivers/misc/eeprom/Kconfig | 29 +++ drivers/misc/eeprom/Makefile | 1 + drivers/misc/eeprom/at24.c | 582 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 612 insertions(+) create mode 100644 drivers/misc/eeprom/Kconfig create mode 100644 drivers/misc/eeprom/Makefile create mode 100644 drivers/misc/eeprom/at24.c (limited to 'drivers/misc/eeprom') diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig new file mode 100644 index 00000000000..0b21778b7d1 --- /dev/null +++ b/drivers/misc/eeprom/Kconfig @@ -0,0 +1,29 @@ +menu "EEPROM support" + +config AT24 + tristate "I2C EEPROMs from most vendors" + depends on I2C && SYSFS && EXPERIMENTAL + help + Enable this driver to get read/write support to most I2C EEPROMs, + after you configure the driver to know about each EEPROM on + your target board. Use these generic chip names, instead of + vendor-specific ones like at24c64 or 24lc02: + + 24c00, 24c01, 24c02, spd (readonly 24c02), 24c04, 24c08, + 24c16, 24c32, 24c64, 24c128, 24c256, 24c512, 24c1024 + + Unless you like data loss puzzles, always be sure that any chip + you configure as a 24c32 (32 kbit) or larger is NOT really a + 24c16 (16 kbit) or smaller, and vice versa. Marking the chip + as read-only won't help recover from this. Also, if your chip + has any software write-protect mechanism you may want to review the + code to make sure this driver won't turn it on by accident. + + If you use this with an SMBus adapter instead of an I2C adapter, + full functionality is not available. Only smaller devices are + supported (24c16 and below, max 4 kByte). + + This driver can also be built as a module. If so, the module + will be called at24. + +endmenu diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile new file mode 100644 index 00000000000..72cd478eb53 --- /dev/null +++ b/drivers/misc/eeprom/Makefile @@ -0,0 +1 @@ +obj-$(CONFIG_AT24) += at24.o diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c new file mode 100644 index 00000000000..d4775528abc --- /dev/null +++ b/drivers/misc/eeprom/at24.c @@ -0,0 +1,582 @@ +/* + * at24.c - handle most I2C EEPROMs + * + * Copyright (C) 2005-2007 David Brownell + * Copyright (C) 2008 Wolfram Sang, Pengutronix + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable. + * Differences between different vendor product lines (like Atmel AT24C or + * MicroChip 24LC, etc) won't much matter for typical read/write access. + * There are also I2C RAM chips, likewise interchangeable. One example + * would be the PCF8570, which acts like a 24c02 EEPROM (256 bytes). + * + * However, misconfiguration can lose data. "Set 16-bit memory address" + * to a part with 8-bit addressing will overwrite data. Writing with too + * big a page size also loses data. And it's not safe to assume that the + * conventional addresses 0x50..0x57 only hold eeproms; a PCF8563 RTC + * uses 0x51, for just one example. + * + * Accordingly, explicit board-specific configuration data should be used + * in almost all cases. (One partial exception is an SMBus used to access + * "SPD" data for DRAM sticks. Those only use 24c02 EEPROMs.) + * + * So this driver uses "new style" I2C driver binding, expecting to be + * told what devices exist. That may be in arch/X/mach-Y/board-Z.c or + * similar kernel-resident tables; or, configuration data coming from + * a bootloader. + * + * Other than binding model, current differences from "eeprom" driver are + * that this one handles write access and isn't restricted to 24c02 devices. + * It also handles larger devices (32 kbit and up) with two-byte addresses, + * which won't work on pure SMBus systems. + */ + +struct at24_data { + struct at24_platform_data chip; + bool use_smbus; + + /* + * Lock protects against activities from other Linux tasks, + * but not from changes by other I2C masters. + */ + struct mutex lock; + struct bin_attribute bin; + + u8 *writebuf; + unsigned write_max; + unsigned num_addresses; + + /* + * Some chips tie up multiple I2C addresses; dummy devices reserve + * them for us, and we'll use them with SMBus calls. + */ + struct i2c_client *client[]; +}; + +/* + * This parameter is to help this driver avoid blocking other drivers out + * of I2C for potentially troublesome amounts of time. With a 100 kHz I2C + * clock, one 256 byte read takes about 1/43 second which is excessive; + * but the 1/170 second it takes at 400 kHz may be quite reasonable; and + * at 1 MHz (Fm+) a 1/430 second delay could easily be invisible. + * + * This value is forced to be a power of two so that writes align on pages. + */ +static unsigned io_limit = 128; +module_param(io_limit, uint, 0); +MODULE_PARM_DESC(io_limit, "Maximum bytes per I/O (default 128)"); + +/* + * Specs often allow 5 msec for a page write, sometimes 20 msec; + * it's important to recover from write timeouts. + */ +static unsigned write_timeout = 25; +module_param(write_timeout, uint, 0); +MODULE_PARM_DESC(write_timeout, "Time (in ms) to try writes (default 25)"); + +#define AT24_SIZE_BYTELEN 5 +#define AT24_SIZE_FLAGS 8 + +#define AT24_BITMASK(x) (BIT(x) - 1) + +/* create non-zero magic value for given eeprom parameters */ +#define AT24_DEVICE_MAGIC(_len, _flags) \ + ((1 << AT24_SIZE_FLAGS | (_flags)) \ + << AT24_SIZE_BYTELEN | ilog2(_len)) + +static const struct i2c_device_id at24_ids[] = { + /* needs 8 addresses as A0-A2 are ignored */ + { "24c00", AT24_DEVICE_MAGIC(128 / 8, AT24_FLAG_TAKE8ADDR) }, + /* old variants can't be handled with this generic entry! */ + { "24c01", AT24_DEVICE_MAGIC(1024 / 8, 0) }, + { "24c02", AT24_DEVICE_MAGIC(2048 / 8, 0) }, + /* spd is a 24c02 in memory DIMMs */ + { "spd", AT24_DEVICE_MAGIC(2048 / 8, + AT24_FLAG_READONLY | AT24_FLAG_IRUGO) }, + { "24c04", AT24_DEVICE_MAGIC(4096 / 8, 0) }, + /* 24rf08 quirk is handled at i2c-core */ + { "24c08", AT24_DEVICE_MAGIC(8192 / 8, 0) }, + { "24c16", AT24_DEVICE_MAGIC(16384 / 8, 0) }, + { "24c32", AT24_DEVICE_MAGIC(32768 / 8, AT24_FLAG_ADDR16) }, + { "24c64", AT24_DEVICE_MAGIC(65536 / 8, AT24_FLAG_ADDR16) }, + { "24c128", AT24_DEVICE_MAGIC(131072 / 8, AT24_FLAG_ADDR16) }, + { "24c256", AT24_DEVICE_MAGIC(262144 / 8, AT24_FLAG_ADDR16) }, + { "24c512", AT24_DEVICE_MAGIC(524288 / 8, AT24_FLAG_ADDR16) }, + { "24c1024", AT24_DEVICE_MAGIC(1048576 / 8, AT24_FLAG_ADDR16) }, + { "at24", 0 }, + { /* END OF LIST */ } +}; +MODULE_DEVICE_TABLE(i2c, at24_ids); + +/*-------------------------------------------------------------------------*/ + +/* + * This routine supports chips which consume multiple I2C addresses. It + * computes the addressing information to be used for a given r/w request. + * Assumes that sanity checks for offset happened at sysfs-layer. + */ +static struct i2c_client *at24_translate_offset(struct at24_data *at24, + unsigned *offset) +{ + unsigned i; + + if (at24->chip.flags & AT24_FLAG_ADDR16) { + i = *offset >> 16; + *offset &= 0xffff; + } else { + i = *offset >> 8; + *offset &= 0xff; + } + + return at24->client[i]; +} + +static ssize_t at24_eeprom_read(struct at24_data *at24, char *buf, + unsigned offset, size_t count) +{ + struct i2c_msg msg[2]; + u8 msgbuf[2]; + struct i2c_client *client; + int status, i; + + memset(msg, 0, sizeof(msg)); + + /* + * REVISIT some multi-address chips don't rollover page reads to + * the next slave address, so we may need to truncate the count. + * Those chips might need another quirk flag. + * + * If the real hardware used four adjacent 24c02 chips and that + * were misconfigured as one 24c08, that would be a similar effect: + * one "eeprom" file not four, but larger reads would fail when + * they crossed certain pages. + */ + + /* + * Slave address and byte offset derive from the offset. Always + * set the byte address; on a multi-master board, another master + * may have changed the chip's "current" address pointer. + */ + client = at24_translate_offset(at24, &offset); + + if (count > io_limit) + count = io_limit; + + /* Smaller eeproms can work given some SMBus extension calls */ + if (at24->use_smbus) { + if (count > I2C_SMBUS_BLOCK_MAX) + count = I2C_SMBUS_BLOCK_MAX; + status = i2c_smbus_read_i2c_block_data(client, offset, + count, buf); + dev_dbg(&client->dev, "smbus read %zu@%d --> %d\n", + count, offset, status); + return (status < 0) ? -EIO : status; + } + + /* + * When we have a better choice than SMBus calls, use a combined + * I2C message. Write address; then read up to io_limit data bytes. + * Note that read page rollover helps us here (unlike writes). + * msgbuf is u8 and will cast to our needs. + */ + i = 0; + if (at24->chip.flags & AT24_FLAG_ADDR16) + msgbuf[i++] = offset >> 8; + msgbuf[i++] = offset; + + msg[0].addr = client->addr; + msg[0].buf = msgbuf; + msg[0].len = i; + + msg[1].addr = client->addr; + msg[1].flags = I2C_M_RD; + msg[1].buf = buf; + msg[1].len = count; + + status = i2c_transfer(client->adapter, msg, 2); + dev_dbg(&client->dev, "i2c read %zu@%d --> %d\n", + count, offset, status); + + if (status == 2) + return count; + else if (status >= 0) + return -EIO; + else + return status; +} + +static ssize_t at24_bin_read(struct kobject *kobj, struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct at24_data *at24; + ssize_t retval = 0; + + at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); + + if (unlikely(!count)) + return count; + + /* + * Read data from chip, protecting against concurrent updates + * from this host, but not from other I2C masters. + */ + mutex_lock(&at24->lock); + + while (count) { + ssize_t status; + + status = at24_eeprom_read(at24, buf, off, count); + if (status <= 0) { + if (retval == 0) + retval = status; + break; + } + buf += status; + off += status; + count -= status; + retval += status; + } + + mutex_unlock(&at24->lock); + + return retval; +} + + +/* + * REVISIT: export at24_bin{read,write}() to let other kernel code use + * eeprom data. For example, it might hold a board's Ethernet address, or + * board-specific calibration data generated on the manufacturing floor. + */ + + +/* + * Note that if the hardware write-protect pin is pulled high, the whole + * chip is normally write protected. But there are plenty of product + * variants here, including OTP fuses and partial chip protect. + * + * We only use page mode writes; the alternative is sloooow. This routine + * writes at most one page. + */ +static ssize_t at24_eeprom_write(struct at24_data *at24, char *buf, + unsigned offset, size_t count) +{ + struct i2c_client *client; + struct i2c_msg msg; + ssize_t status; + unsigned long timeout, write_time; + unsigned next_page; + + /* Get corresponding I2C address and adjust offset */ + client = at24_translate_offset(at24, &offset); + + /* write_max is at most a page */ + if (count > at24->write_max) + count = at24->write_max; + + /* Never roll over backwards, to the start of this page */ + next_page = roundup(offset + 1, at24->chip.page_size); + if (offset + count > next_page) + count = next_page - offset; + + /* If we'll use I2C calls for I/O, set up the message */ + if (!at24->use_smbus) { + int i = 0; + + msg.addr = client->addr; + msg.flags = 0; + + /* msg.buf is u8 and casts will mask the values */ + msg.buf = at24->writebuf; + if (at24->chip.flags & AT24_FLAG_ADDR16) + msg.buf[i++] = offset >> 8; + + msg.buf[i++] = offset; + memcpy(&msg.buf[i], buf, count); + msg.len = i + count; + } + + /* + * Writes fail if the previous one didn't complete yet. We may + * loop a few times until this one succeeds, waiting at least + * long enough for one entire page write to work. + */ + timeout = jiffies + msecs_to_jiffies(write_timeout); + do { + write_time = jiffies; + if (at24->use_smbus) { + status = i2c_smbus_write_i2c_block_data(client, + offset, count, buf); + if (status == 0) + status = count; + } else { + status = i2c_transfer(client->adapter, &msg, 1); + if (status == 1) + status = count; + } + dev_dbg(&client->dev, "write %zu@%d --> %zd (%ld)\n", + count, offset, status, jiffies); + + if (status == count) + return count; + + /* REVISIT: at HZ=100, this is sloooow */ + msleep(1); + } while (time_before(write_time, timeout)); + + return -ETIMEDOUT; +} + +static ssize_t at24_bin_write(struct kobject *kobj, struct bin_attribute *attr, + char *buf, loff_t off, size_t count) +{ + struct at24_data *at24; + ssize_t retval = 0; + + at24 = dev_get_drvdata(container_of(kobj, struct device, kobj)); + + if (unlikely(!count)) + return count; + + /* + * Write data to chip, protecting against concurrent updates + * from this host, but not from other I2C masters. + */ + mutex_lock(&at24->lock); + + while (count) { + ssize_t status; + + status = at24_eeprom_write(at24, buf, off, count); + if (status <= 0) { + if (retval == 0) + retval = status; + break; + } + buf += status; + off += status; + count -= status; + retval += status; + } + + mutex_unlock(&at24->lock); + + return retval; +} + +/*-------------------------------------------------------------------------*/ + +static int at24_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + struct at24_platform_data chip; + bool writable; + bool use_smbus = false; + struct at24_data *at24; + int err; + unsigned i, num_addresses; + kernel_ulong_t magic; + + if (client->dev.platform_data) { + chip = *(struct at24_platform_data *)client->dev.platform_data; + } else { + if (!id->driver_data) { + err = -ENODEV; + goto err_out; + } + magic = id->driver_data; + chip.byte_len = BIT(magic & AT24_BITMASK(AT24_SIZE_BYTELEN)); + magic >>= AT24_SIZE_BYTELEN; + chip.flags = magic & AT24_BITMASK(AT24_SIZE_FLAGS); + /* + * This is slow, but we can't know all eeproms, so we better + * play safe. Specifying custom eeprom-types via platform_data + * is recommended anyhow. + */ + chip.page_size = 1; + } + + if (!is_power_of_2(chip.byte_len)) + dev_warn(&client->dev, + "byte_len looks suspicious (no power of 2)!\n"); + if (!is_power_of_2(chip.page_size)) + dev_warn(&client->dev, + "page_size looks suspicious (no power of 2)!\n"); + + /* Use I2C operations unless we're stuck with SMBus extensions. */ + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { + if (chip.flags & AT24_FLAG_ADDR16) { + err = -EPFNOSUPPORT; + goto err_out; + } + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { + err = -EPFNOSUPPORT; + goto err_out; + } + use_smbus = true; + } + + if (chip.flags & AT24_FLAG_TAKE8ADDR) + num_addresses = 8; + else + num_addresses = DIV_ROUND_UP(chip.byte_len, + (chip.flags & AT24_FLAG_ADDR16) ? 65536 : 256); + + at24 = kzalloc(sizeof(struct at24_data) + + num_addresses * sizeof(struct i2c_client *), GFP_KERNEL); + if (!at24) { + err = -ENOMEM; + goto err_out; + } + + mutex_init(&at24->lock); + at24->use_smbus = use_smbus; + at24->chip = chip; + at24->num_addresses = num_addresses; + + /* + * Export the EEPROM bytes through sysfs, since that's convenient. + * By default, only root should see the data (maybe passwords etc) + */ + at24->bin.attr.name = "eeprom"; + at24->bin.attr.mode = chip.flags & AT24_FLAG_IRUGO ? S_IRUGO : S_IRUSR; + at24->bin.read = at24_bin_read; + at24->bin.size = chip.byte_len; + + writable = !(chip.flags & AT24_FLAG_READONLY); + if (writable) { + if (!use_smbus || i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) { + + unsigned write_max = chip.page_size; + + at24->bin.write = at24_bin_write; + at24->bin.attr.mode |= S_IWUSR; + + if (write_max > io_limit) + write_max = io_limit; + if (use_smbus && write_max > I2C_SMBUS_BLOCK_MAX) + write_max = I2C_SMBUS_BLOCK_MAX; + at24->write_max = write_max; + + /* buffer (data + address at the beginning) */ + at24->writebuf = kmalloc(write_max + 2, GFP_KERNEL); + if (!at24->writebuf) { + err = -ENOMEM; + goto err_struct; + } + } else { + dev_warn(&client->dev, + "cannot write due to controller restrictions."); + } + } + + at24->client[0] = client; + + /* use dummy devices for multiple-address chips */ + for (i = 1; i < num_addresses; i++) { + at24->client[i] = i2c_new_dummy(client->adapter, + client->addr + i); + if (!at24->client[i]) { + dev_err(&client->dev, "address 0x%02x unavailable\n", + client->addr + i); + err = -EADDRINUSE; + goto err_clients; + } + } + + err = sysfs_create_bin_file(&client->dev.kobj, &at24->bin); + if (err) + goto err_clients; + + i2c_set_clientdata(client, at24); + + dev_info(&client->dev, "%zu byte %s EEPROM %s\n", + at24->bin.size, client->name, + writable ? "(writable)" : "(read-only)"); + dev_dbg(&client->dev, + "page_size %d, num_addresses %d, write_max %d%s\n", + chip.page_size, num_addresses, + at24->write_max, + use_smbus ? ", use_smbus" : ""); + + return 0; + +err_clients: + for (i = 1; i < num_addresses; i++) + if (at24->client[i]) + i2c_unregister_device(at24->client[i]); + + kfree(at24->writebuf); +err_struct: + kfree(at24); +err_out: + dev_dbg(&client->dev, "probe error %d\n", err); + return err; +} + +static int __devexit at24_remove(struct i2c_client *client) +{ + struct at24_data *at24; + int i; + + at24 = i2c_get_clientdata(client); + sysfs_remove_bin_file(&client->dev.kobj, &at24->bin); + + for (i = 1; i < at24->num_addresses; i++) + i2c_unregister_device(at24->client[i]); + + kfree(at24->writebuf); + kfree(at24); + i2c_set_clientdata(client, NULL); + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static struct i2c_driver at24_driver = { + .driver = { + .name = "at24", + .owner = THIS_MODULE, + }, + .probe = at24_probe, + .remove = __devexit_p(at24_remove), + .id_table = at24_ids, +}; + +static int __init at24_init(void) +{ + io_limit = rounddown_pow_of_two(io_limit); + return i2c_add_driver(&at24_driver); +} +module_init(at24_init); + +static void __exit at24_exit(void) +{ + i2c_del_driver(&at24_driver); +} +module_exit(at24_exit); + +MODULE_DESCRIPTION("Driver for most I2C EEPROMs"); +MODULE_AUTHOR("David Brownell and Wolfram Sang"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3 From 2e157888f132131f8877affd2785dcee4c227c1d Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 26 Jan 2009 21:19:53 +0100 Subject: i2c: Move old eeprom driver to /drivers/misc/eeprom Update Kconfig text to specify this driver as I2C. Signed-off-by: Wolfram Sang Signed-off-by: Jean Delvare --- drivers/misc/eeprom/Kconfig | 11 ++ drivers/misc/eeprom/Makefile | 1 + drivers/misc/eeprom/eeprom.c | 257 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 269 insertions(+) create mode 100644 drivers/misc/eeprom/eeprom.c (limited to 'drivers/misc/eeprom') diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig index 0b21778b7d1..3d31b664424 100644 --- a/drivers/misc/eeprom/Kconfig +++ b/drivers/misc/eeprom/Kconfig @@ -26,4 +26,15 @@ config AT24 This driver can also be built as a module. If so, the module will be called at24. +config SENSORS_EEPROM + tristate "Old I2C EEPROM reader" + depends on I2C && EXPERIMENTAL + help + If you say yes here you get read-only access to the EEPROM data + available on modern memory DIMMs and Sony Vaio laptops via I2C. Such + EEPROMs could theoretically be available on other devices as well. + + This driver can also be built as a module. If so, the module + will be called eeprom. + endmenu diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile index 72cd478eb53..a3dad28f272 100644 --- a/drivers/misc/eeprom/Makefile +++ b/drivers/misc/eeprom/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_AT24) += at24.o +obj-$(CONFIG_SENSORS_EEPROM) += eeprom.o diff --git a/drivers/misc/eeprom/eeprom.c b/drivers/misc/eeprom/eeprom.c new file mode 100644 index 00000000000..2c27193aeaa --- /dev/null +++ b/drivers/misc/eeprom/eeprom.c @@ -0,0 +1,257 @@ +/* + Copyright (C) 1998, 1999 Frodo Looijaard and + Philip Edelbrock + Copyright (C) 2003 Greg Kroah-Hartman + Copyright (C) 2003 IBM Corp. + Copyright (C) 2004 Jean Delvare + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. +*/ + +#include +#include +#include +#include +#include +#include +#include + +/* Addresses to scan */ +static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54, + 0x55, 0x56, 0x57, I2C_CLIENT_END }; + +/* Insmod parameters */ +I2C_CLIENT_INSMOD_1(eeprom); + + +/* 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 kobject *kobj, struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj)); + struct eeprom_data *data = i2c_get_clientdata(client); + u8 slice; + + if (off > EEPROM_SIZE) + return 0; + if (off + count > EEPROM_SIZE) + count = EEPROM_SIZE - off; + + /* 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 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, int kind, + 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; + + strlcpy(info->type, "eeprom", I2C_NAME_SIZE); + + return 0; +} + +static int eeprom_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = client->adapter; + struct eeprom_data *data; + int err; + + if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) { + err = -ENOMEM; + goto exit; + } + + 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; + } + } + + /* create the sysfs eeprom file */ + err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr); + if (err) + goto exit_kfree; + + return 0; + +exit_kfree: + kfree(data); +exit: + return err; +} + +static int eeprom_remove(struct i2c_client *client) +{ + sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr); + kfree(i2c_get_clientdata(client)); + + return 0; +} + +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_data = &addr_data, +}; + +static int __init eeprom_init(void) +{ + return i2c_add_driver(&eeprom_driver); +} + +static void __exit eeprom_exit(void) +{ + i2c_del_driver(&eeprom_driver); +} + + +MODULE_AUTHOR("Frodo Looijaard and " + "Philip Edelbrock and " + "Greg Kroah-Hartman "); +MODULE_DESCRIPTION("I2C EEPROM driver"); +MODULE_LICENSE("GPL"); + +module_init(eeprom_init); +module_exit(eeprom_exit); -- cgit v1.2.3 From e51d565ff6bb1cedc10568425511badf0633a212 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 26 Jan 2009 21:19:54 +0100 Subject: spi: Move at25 (for SPI eeproms) to /drivers/misc/eeprom Signed-off-by: Wolfram Sang Signed-off-by: Jean Delvare --- drivers/misc/eeprom/Kconfig | 11 ++ drivers/misc/eeprom/Makefile | 1 + drivers/misc/eeprom/at25.c | 389 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 401 insertions(+) create mode 100644 drivers/misc/eeprom/at25.c (limited to 'drivers/misc/eeprom') diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig index 3d31b664424..5bf3c92d716 100644 --- a/drivers/misc/eeprom/Kconfig +++ b/drivers/misc/eeprom/Kconfig @@ -26,6 +26,17 @@ config AT24 This driver can also be built as a module. If so, the module will be called at24. +config SPI_AT25 + tristate "SPI EEPROMs from most vendors" + depends on SPI && SYSFS + help + Enable this driver to get read/write support to most SPI EEPROMs, + after you configure the board init code to know about each eeprom + on your target board. + + This driver can also be built as a module. If so, the module + will be called at25. + config SENSORS_EEPROM tristate "Old I2C EEPROM reader" depends on I2C && EXPERIMENTAL diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile index a3dad28f272..a4fb5cf8ffe 100644 --- a/drivers/misc/eeprom/Makefile +++ b/drivers/misc/eeprom/Makefile @@ -1,2 +1,3 @@ obj-$(CONFIG_AT24) += at24.o +obj-$(CONFIG_SPI_AT25) += at25.o obj-$(CONFIG_SENSORS_EEPROM) += eeprom.o diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c new file mode 100644 index 00000000000..290dbe99647 --- /dev/null +++ b/drivers/misc/eeprom/at25.c @@ -0,0 +1,389 @@ +/* + * at25.c -- support most SPI EEPROMs, such as Atmel AT25 models + * + * Copyright (C) 2006 David Brownell + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + + +/* + * NOTE: this is an *EEPROM* driver. The vagaries of product naming + * mean that some AT25 products are EEPROMs, and others are FLASH. + * Handle FLASH chips with the drivers/mtd/devices/m25p80.c driver, + * not this one! + */ + +struct at25_data { + struct spi_device *spi; + struct mutex lock; + struct spi_eeprom chip; + struct bin_attribute bin; + unsigned addrlen; +}; + +#define AT25_WREN 0x06 /* latch the write enable */ +#define AT25_WRDI 0x04 /* reset the write enable */ +#define AT25_RDSR 0x05 /* read status register */ +#define AT25_WRSR 0x01 /* write status register */ +#define AT25_READ 0x03 /* read byte(s) */ +#define AT25_WRITE 0x02 /* write byte(s)/sector */ + +#define AT25_SR_nRDY 0x01 /* nRDY = write-in-progress */ +#define AT25_SR_WEN 0x02 /* write enable (latched) */ +#define AT25_SR_BP0 0x04 /* BP for software writeprotect */ +#define AT25_SR_BP1 0x08 +#define AT25_SR_WPEN 0x80 /* writeprotect enable */ + + +#define EE_MAXADDRLEN 3 /* 24 bit addresses, up to 2 MBytes */ + +/* Specs often allow 5 msec for a page write, sometimes 20 msec; + * it's important to recover from write timeouts. + */ +#define EE_TIMEOUT 25 + +/*-------------------------------------------------------------------------*/ + +#define io_limit PAGE_SIZE /* bytes */ + +static ssize_t +at25_ee_read( + struct at25_data *at25, + char *buf, + unsigned offset, + size_t count +) +{ + u8 command[EE_MAXADDRLEN + 1]; + u8 *cp; + ssize_t status; + struct spi_transfer t[2]; + struct spi_message m; + + cp = command; + *cp++ = AT25_READ; + + /* 8/16/24-bit address is written MSB first */ + switch (at25->addrlen) { + default: /* case 3 */ + *cp++ = offset >> 16; + case 2: + *cp++ = offset >> 8; + case 1: + case 0: /* can't happen: for better codegen */ + *cp++ = offset >> 0; + } + + spi_message_init(&m); + memset(t, 0, sizeof t); + + t[0].tx_buf = command; + t[0].len = at25->addrlen + 1; + spi_message_add_tail(&t[0], &m); + + t[1].rx_buf = buf; + t[1].len = count; + spi_message_add_tail(&t[1], &m); + + mutex_lock(&at25->lock); + + /* Read it all at once. + * + * REVISIT that's potentially a problem with large chips, if + * other devices on the bus need to be accessed regularly or + * this chip is clocked very slowly + */ + status = spi_sync(at25->spi, &m); + dev_dbg(&at25->spi->dev, + "read %Zd bytes at %d --> %d\n", + count, offset, (int) status); + + mutex_unlock(&at25->lock); + return status ? status : count; +} + +static ssize_t +at25_bin_read(struct kobject *kobj, struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + struct device *dev; + struct at25_data *at25; + + dev = container_of(kobj, struct device, kobj); + at25 = dev_get_drvdata(dev); + + if (unlikely(off >= at25->bin.size)) + return 0; + if ((off + count) > at25->bin.size) + count = at25->bin.size - off; + if (unlikely(!count)) + return count; + + return at25_ee_read(at25, buf, off, count); +} + + +static ssize_t +at25_ee_write(struct at25_data *at25, char *buf, loff_t off, size_t count) +{ + ssize_t status = 0; + unsigned written = 0; + unsigned buf_size; + u8 *bounce; + + /* Temp buffer starts with command and address */ + buf_size = at25->chip.page_size; + if (buf_size > io_limit) + buf_size = io_limit; + bounce = kmalloc(buf_size + at25->addrlen + 1, GFP_KERNEL); + if (!bounce) + return -ENOMEM; + + /* For write, rollover is within the page ... so we write at + * most one page, then manually roll over to the next page. + */ + bounce[0] = AT25_WRITE; + mutex_lock(&at25->lock); + do { + unsigned long timeout, retries; + unsigned segment; + unsigned offset = (unsigned) off; + u8 *cp = bounce + 1; + + *cp = AT25_WREN; + status = spi_write(at25->spi, cp, 1); + if (status < 0) { + dev_dbg(&at25->spi->dev, "WREN --> %d\n", + (int) status); + break; + } + + /* 8/16/24-bit address is written MSB first */ + switch (at25->addrlen) { + default: /* case 3 */ + *cp++ = offset >> 16; + case 2: + *cp++ = offset >> 8; + case 1: + case 0: /* can't happen: for better codegen */ + *cp++ = offset >> 0; + } + + /* Write as much of a page as we can */ + segment = buf_size - (offset % buf_size); + if (segment > count) + segment = count; + memcpy(cp, buf, segment); + status = spi_write(at25->spi, bounce, + segment + at25->addrlen + 1); + dev_dbg(&at25->spi->dev, + "write %u bytes at %u --> %d\n", + segment, offset, (int) status); + if (status < 0) + break; + + /* REVISIT this should detect (or prevent) failed writes + * to readonly sections of the EEPROM... + */ + + /* Wait for non-busy status */ + timeout = jiffies + msecs_to_jiffies(EE_TIMEOUT); + retries = 0; + do { + int sr; + + sr = spi_w8r8(at25->spi, AT25_RDSR); + if (sr < 0 || (sr & AT25_SR_nRDY)) { + dev_dbg(&at25->spi->dev, + "rdsr --> %d (%02x)\n", sr, sr); + /* at HZ=100, this is sloooow */ + msleep(1); + continue; + } + if (!(sr & AT25_SR_nRDY)) + break; + } while (retries++ < 3 || time_before_eq(jiffies, timeout)); + + if (time_after(jiffies, timeout)) { + dev_err(&at25->spi->dev, + "write %d bytes offset %d, " + "timeout after %u msecs\n", + segment, offset, + jiffies_to_msecs(jiffies - + (timeout - EE_TIMEOUT))); + status = -ETIMEDOUT; + break; + } + + off += segment; + buf += segment; + count -= segment; + written += segment; + + } while (count > 0); + + mutex_unlock(&at25->lock); + + kfree(bounce); + return written ? written : status; +} + +static ssize_t +at25_bin_write(struct kobject *kobj, struct bin_attribute *bin_attr, + char *buf, loff_t off, size_t count) +{ + struct device *dev; + struct at25_data *at25; + + dev = container_of(kobj, struct device, kobj); + at25 = dev_get_drvdata(dev); + + if (unlikely(off >= at25->bin.size)) + return -EFBIG; + if ((off + count) > at25->bin.size) + count = at25->bin.size - off; + if (unlikely(!count)) + return count; + + return at25_ee_write(at25, buf, off, count); +} + +/*-------------------------------------------------------------------------*/ + +static int at25_probe(struct spi_device *spi) +{ + struct at25_data *at25 = NULL; + const struct spi_eeprom *chip; + int err; + int sr; + int addrlen; + + /* Chip description */ + chip = spi->dev.platform_data; + if (!chip) { + dev_dbg(&spi->dev, "no chip description\n"); + err = -ENODEV; + goto fail; + } + + /* For now we only support 8/16/24 bit addressing */ + if (chip->flags & EE_ADDR1) + addrlen = 1; + else if (chip->flags & EE_ADDR2) + addrlen = 2; + else if (chip->flags & EE_ADDR3) + addrlen = 3; + else { + dev_dbg(&spi->dev, "unsupported address type\n"); + err = -EINVAL; + goto fail; + } + + /* Ping the chip ... the status register is pretty portable, + * unlike probing manufacturer IDs. We do expect that system + * firmware didn't write it in the past few milliseconds! + */ + sr = spi_w8r8(spi, AT25_RDSR); + if (sr < 0 || sr & AT25_SR_nRDY) { + dev_dbg(&spi->dev, "rdsr --> %d (%02x)\n", sr, sr); + err = -ENXIO; + goto fail; + } + + if (!(at25 = kzalloc(sizeof *at25, GFP_KERNEL))) { + err = -ENOMEM; + goto fail; + } + + mutex_init(&at25->lock); + at25->chip = *chip; + at25->spi = spi_dev_get(spi); + dev_set_drvdata(&spi->dev, at25); + at25->addrlen = addrlen; + + /* Export the EEPROM bytes through sysfs, since that's convenient. + * Default to root-only access to the data; EEPROMs often hold data + * that's sensitive for read and/or write, like ethernet addresses, + * security codes, board-specific manufacturing calibrations, etc. + */ + at25->bin.attr.name = "eeprom"; + at25->bin.attr.mode = S_IRUSR; + at25->bin.read = at25_bin_read; + + at25->bin.size = at25->chip.byte_len; + if (!(chip->flags & EE_READONLY)) { + at25->bin.write = at25_bin_write; + at25->bin.attr.mode |= S_IWUSR; + } + + err = sysfs_create_bin_file(&spi->dev.kobj, &at25->bin); + if (err) + goto fail; + + dev_info(&spi->dev, "%Zd %s %s eeprom%s, pagesize %u\n", + (at25->bin.size < 1024) + ? at25->bin.size + : (at25->bin.size / 1024), + (at25->bin.size < 1024) ? "Byte" : "KByte", + at25->chip.name, + (chip->flags & EE_READONLY) ? " (readonly)" : "", + at25->chip.page_size); + return 0; +fail: + dev_dbg(&spi->dev, "probe err %d\n", err); + kfree(at25); + return err; +} + +static int __devexit at25_remove(struct spi_device *spi) +{ + struct at25_data *at25; + + at25 = dev_get_drvdata(&spi->dev); + sysfs_remove_bin_file(&spi->dev.kobj, &at25->bin); + kfree(at25); + return 0; +} + +/*-------------------------------------------------------------------------*/ + +static struct spi_driver at25_driver = { + .driver = { + .name = "at25", + .owner = THIS_MODULE, + }, + .probe = at25_probe, + .remove = __devexit_p(at25_remove), +}; + +static int __init at25_init(void) +{ + return spi_register_driver(&at25_driver); +} +module_init(at25_init); + +static void __exit at25_exit(void) +{ + spi_unregister_driver(&at25_driver); +} +module_exit(at25_exit); + +MODULE_DESCRIPTION("Driver for most SPI EEPROMs"); +MODULE_AUTHOR("David Brownell"); +MODULE_LICENSE("GPL"); + -- cgit v1.2.3 From 0eb6da20681db9b5d5769d3e1aca877f4a77d8fb Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Mon, 26 Jan 2009 21:19:54 +0100 Subject: eeprom: Move 93cx6 eeprom driver to /drivers/misc/eeprom Signed-off-by: Wolfram Sang Signed-off-by: Jean Delvare --- drivers/misc/eeprom/Kconfig | 8 ++ drivers/misc/eeprom/Makefile | 1 + drivers/misc/eeprom/eeprom_93cx6.c | 240 +++++++++++++++++++++++++++++++++++++ 3 files changed, 249 insertions(+) create mode 100644 drivers/misc/eeprom/eeprom_93cx6.c (limited to 'drivers/misc/eeprom') diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig index 5bf3c92d716..62aae334ee6 100644 --- a/drivers/misc/eeprom/Kconfig +++ b/drivers/misc/eeprom/Kconfig @@ -48,4 +48,12 @@ config SENSORS_EEPROM This driver can also be built as a module. If so, the module will be called eeprom. +config EEPROM_93CX6 + tristate "EEPROM 93CX6 support" + help + This is a driver for the EEPROM chipsets 93c46 and 93c66. + The driver supports both read as well as write commands. + + If unsure, say N. + endmenu diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile index a4fb5cf8ffe..3b7af6df79a 100644 --- a/drivers/misc/eeprom/Makefile +++ b/drivers/misc/eeprom/Makefile @@ -1,3 +1,4 @@ obj-$(CONFIG_AT24) += at24.o obj-$(CONFIG_SPI_AT25) += at25.o obj-$(CONFIG_SENSORS_EEPROM) += eeprom.o +obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o diff --git a/drivers/misc/eeprom/eeprom_93cx6.c b/drivers/misc/eeprom/eeprom_93cx6.c new file mode 100644 index 00000000000..15b1780025c --- /dev/null +++ b/drivers/misc/eeprom/eeprom_93cx6.c @@ -0,0 +1,240 @@ +/* + Copyright (C) 2004 - 2006 rt2x00 SourceForge Project + + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the + Free Software Foundation, Inc., + 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +/* + Module: eeprom_93cx6 + Abstract: EEPROM reader routines for 93cx6 chipsets. + Supported chipsets: 93c46 & 93c66. + */ + +#include +#include +#include +#include + +MODULE_AUTHOR("http://rt2x00.serialmonkey.com"); +MODULE_VERSION("1.0"); +MODULE_DESCRIPTION("EEPROM 93cx6 chip driver"); +MODULE_LICENSE("GPL"); + +static inline void eeprom_93cx6_pulse_high(struct eeprom_93cx6 *eeprom) +{ + eeprom->reg_data_clock = 1; + eeprom->register_write(eeprom); + + /* + * Add a short delay for the pulse to work. + * According to the specifications the "maximum minimum" + * time should be 450ns. + */ + ndelay(450); +} + +static inline void eeprom_93cx6_pulse_low(struct eeprom_93cx6 *eeprom) +{ + eeprom->reg_data_clock = 0; + eeprom->register_write(eeprom); + + /* + * Add a short delay for the pulse to work. + * According to the specifications the "maximum minimum" + * time should be 450ns. + */ + ndelay(450); +} + +static void eeprom_93cx6_startup(struct eeprom_93cx6 *eeprom) +{ + /* + * Clear all flags, and enable chip select. + */ + eeprom->register_read(eeprom); + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + eeprom->reg_data_clock = 0; + eeprom->reg_chip_select = 1; + eeprom->register_write(eeprom); + + /* + * kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); +} + +static void eeprom_93cx6_cleanup(struct eeprom_93cx6 *eeprom) +{ + /* + * Clear chip_select and data_in flags. + */ + eeprom->register_read(eeprom); + eeprom->reg_data_in = 0; + eeprom->reg_chip_select = 0; + eeprom->register_write(eeprom); + + /* + * kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); +} + +static void eeprom_93cx6_write_bits(struct eeprom_93cx6 *eeprom, + const u16 data, const u16 count) +{ + unsigned int i; + + eeprom->register_read(eeprom); + + /* + * Clear data flags. + */ + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + + /* + * Start writing all bits. + */ + for (i = count; i > 0; i--) { + /* + * Check if this bit needs to be set. + */ + eeprom->reg_data_in = !!(data & (1 << (i - 1))); + + /* + * Write the bit to the eeprom register. + */ + eeprom->register_write(eeprom); + + /* + * Kick a pulse. + */ + eeprom_93cx6_pulse_high(eeprom); + eeprom_93cx6_pulse_low(eeprom); + } + + eeprom->reg_data_in = 0; + eeprom->register_write(eeprom); +} + +static void eeprom_93cx6_read_bits(struct eeprom_93cx6 *eeprom, + u16 *data, const u16 count) +{ + unsigned int i; + u16 buf = 0; + + eeprom->register_read(eeprom); + + /* + * Clear data flags. + */ + eeprom->reg_data_in = 0; + eeprom->reg_data_out = 0; + + /* + * Start reading all bits. + */ + for (i = count; i > 0; i--) { + eeprom_93cx6_pulse_high(eeprom); + + eeprom->register_read(eeprom); + + /* + * Clear data_in flag. + */ + eeprom->reg_data_in = 0; + + /* + * Read if the bit has been set. + */ + if (eeprom->reg_data_out) + buf |= (1 << (i - 1)); + + eeprom_93cx6_pulse_low(eeprom); + } + + *data = buf; +} + +/** + * eeprom_93cx6_read - Read multiple words from eeprom + * @eeprom: Pointer to eeprom structure + * @word: Word index from where we should start reading + * @data: target pointer where the information will have to be stored + * + * This function will read the eeprom data as host-endian word + * into the given data pointer. + */ +void eeprom_93cx6_read(struct eeprom_93cx6 *eeprom, const u8 word, + u16 *data) +{ + u16 command; + + /* + * Initialize the eeprom register + */ + eeprom_93cx6_startup(eeprom); + + /* + * Select the read opcode and the word to be read. + */ + command = (PCI_EEPROM_READ_OPCODE << eeprom->width) | word; + eeprom_93cx6_write_bits(eeprom, command, + PCI_EEPROM_WIDTH_OPCODE + eeprom->width); + + /* + * Read the requested 16 bits. + */ + eeprom_93cx6_read_bits(eeprom, data, 16); + + /* + * Cleanup eeprom register. + */ + eeprom_93cx6_cleanup(eeprom); +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_read); + +/** + * eeprom_93cx6_multiread - Read multiple words from eeprom + * @eeprom: Pointer to eeprom structure + * @word: Word index from where we should start reading + * @data: target pointer where the information will have to be stored + * @words: Number of words that should be read. + * + * This function will read all requested words from the eeprom, + * this is done by calling eeprom_93cx6_read() multiple times. + * But with the additional change that while the eeprom_93cx6_read + * will return host ordered bytes, this method will return little + * endian words. + */ +void eeprom_93cx6_multiread(struct eeprom_93cx6 *eeprom, const u8 word, + __le16 *data, const u16 words) +{ + unsigned int i; + u16 tmp; + + for (i = 0; i < words; i++) { + tmp = 0; + eeprom_93cx6_read(eeprom, word + i, &tmp); + data[i] = cpu_to_le16(tmp); + } +} +EXPORT_SYMBOL_GPL(eeprom_93cx6_multiread); + -- cgit v1.2.3 From dd7f8dbe2b3c0611ba969cd867c10cb63d163e25 Mon Sep 17 00:00:00 2001 From: Jean Delvare Date: Mon, 26 Jan 2009 21:19:57 +0100 Subject: eeprom: More consistent symbol names Now that all EEPROM drivers live in the same place, let's harmonize their symbol names. Also fix eeprom's dependencies, it definitely needs sysfs, and is no longer experimental after many years in the kernel tree. Signed-off-by: Jean Delvare Acked-by: Wolfram Sang Cc: David Brownell --- drivers/misc/eeprom/Kconfig | 8 ++++---- drivers/misc/eeprom/Makefile | 6 +++--- 2 files changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/misc/eeprom') diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig index 62aae334ee6..c76df8cda5e 100644 --- a/drivers/misc/eeprom/Kconfig +++ b/drivers/misc/eeprom/Kconfig @@ -1,6 +1,6 @@ menu "EEPROM support" -config AT24 +config EEPROM_AT24 tristate "I2C EEPROMs from most vendors" depends on I2C && SYSFS && EXPERIMENTAL help @@ -26,7 +26,7 @@ config AT24 This driver can also be built as a module. If so, the module will be called at24. -config SPI_AT25 +config EEPROM_AT25 tristate "SPI EEPROMs from most vendors" depends on SPI && SYSFS help @@ -37,9 +37,9 @@ config SPI_AT25 This driver can also be built as a module. If so, the module will be called at25. -config SENSORS_EEPROM +config EEPROM_LEGACY tristate "Old I2C EEPROM reader" - depends on I2C && EXPERIMENTAL + depends on I2C && SYSFS help If you say yes here you get read-only access to the EEPROM data available on modern memory DIMMs and Sony Vaio laptops via I2C. Such diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile index 3b7af6df79a..539dd8f8812 100644 --- a/drivers/misc/eeprom/Makefile +++ b/drivers/misc/eeprom/Makefile @@ -1,4 +1,4 @@ -obj-$(CONFIG_AT24) += at24.o -obj-$(CONFIG_SPI_AT25) += at25.o -obj-$(CONFIG_SENSORS_EEPROM) += eeprom.o +obj-$(CONFIG_EEPROM_AT24) += at24.o +obj-$(CONFIG_EEPROM_AT25) += at25.o +obj-$(CONFIG_EEPROM_LEGACY) += eeprom.o obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o -- cgit v1.2.3