diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/at25.c | 389 |
3 files changed, 0 insertions, 401 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index 4a6fe01831a8..83a185d52961 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -230,17 +230,6 @@ config SPI_XILINX # comment "SPI Protocol Masters" -config SPI_AT25 - tristate "SPI EEPROMs from most vendors" - depends on 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 SPI_SPIDEV tristate "User mode SPI device driver support" depends on EXPERIMENTAL diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index 5e9f521b8844..5d0451936d86 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -33,7 +33,6 @@ obj-$(CONFIG_SPI_SH_SCI) += spi_sh_sci.o # ... add above this line ... # SPI protocol drivers (device/link on bus) -obj-$(CONFIG_SPI_AT25) += at25.o obj-$(CONFIG_SPI_SPIDEV) += spidev.o obj-$(CONFIG_SPI_TLE62X0) += tle62x0.o # ... add above this line ... diff --git a/drivers/spi/at25.c b/drivers/spi/at25.c deleted file mode 100644 index 290dbe99647a..000000000000 --- a/drivers/spi/at25.c +++ /dev/null @@ -1,389 +0,0 @@ -/* - * 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 <linux/kernel.h> -#include <linux/init.h> -#include <linux/module.h> -#include <linux/slab.h> -#include <linux/delay.h> -#include <linux/device.h> -#include <linux/sched.h> - -#include <linux/spi/spi.h> -#include <linux/spi/eeprom.h> - - -/* - * 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"); - |