This series adds a driver for at24 eeproms. Much of the guts of the code is taken from the at24 driver in the linux kernel.
Signed-off-by: Marc Reilly <[email protected]> --- drivers/eeprom/Kconfig | 7 +++ drivers/eeprom/Makefile | 1 + drivers/eeprom/at24.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 142 insertions(+), 0 deletions(-) create mode 100644 drivers/eeprom/at24.c diff --git a/drivers/eeprom/Kconfig b/drivers/eeprom/Kconfig index a0b5489..56dfd1a 100644 --- a/drivers/eeprom/Kconfig +++ b/drivers/eeprom/Kconfig @@ -8,4 +8,11 @@ config EEPROM_AT25 after you configure the board init code to know about each eeprom on your target board. +config EEPROM_AT24 + bool "at24 based eeprom" + depends on I2C + help + Provides read/write for the at24 family of I2C EEPROMS. + Currently only the 2K bit versions are supported. + endmenu diff --git a/drivers/eeprom/Makefile b/drivers/eeprom/Makefile index e323bd0..e287eb0 100644 --- a/drivers/eeprom/Makefile +++ b/drivers/eeprom/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_EEPROM_AT25) += at25.o +obj-$(CONFIG_EEPROM_AT24) += at24.o diff --git a/drivers/eeprom/at24.c b/drivers/eeprom/at24.c new file mode 100644 index 0000000..fd578b1 --- /dev/null +++ b/drivers/eeprom/at24.c @@ -0,0 +1,134 @@ +/* + * Copyright (C) 2007 Sascha Hauer, Pengutronix + * 2009 Marc Kleine-Budde <[email protected]> + * 2010 Marc Reilly, Creative Product Design + * + * 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 + * + */ + +#include <common.h> +#include <init.h> +#include <driver.h> +#include <xfuncs.h> +#include <errno.h> + +#include <i2c/i2c.h> + +#define DRIVERNAME "eeprom" + +struct at24 { + struct cdev cdev; + struct i2c_client *client; + /* size in bytes */ + unsigned int size; +}; + +#define to_at24(a) container_of(a, struct at24, cdev) + +static ssize_t at24_read(struct cdev *cdev, void *_buf, size_t count, + ulong offset, ulong flags) +{ + struct at24 *priv = to_at24(cdev); + u8 *buf = _buf; + size_t i = count; + ssize_t numwritten = 0; + int retries = 5; + int ret; + + while (i && retries) { + ret = i2c_read_reg(priv->client, offset, buf, i); + if (ret < 0) + return (ssize_t)ret; + else if (ret == 0) + --retries; + + numwritten += ret; + i -= ret; + offset += ret; + buf += ret; + } + + return numwritten; +} + +static ssize_t at24_write(struct cdev *cdev, const void *_buf, size_t count, + ulong offset, ulong flags) +{ + struct at24 *priv = to_at24(cdev); + const u8 *buf = _buf; + const int maxwrite = 8; + int numtowrite; + ssize_t numwritten = 0; + + while (count) { + int ret; + + numtowrite = count; + if (numtowrite > maxwrite) + numtowrite = maxwrite; + + ret = i2c_write_reg(priv->client, offset, buf, numtowrite); + if (ret < 0) + return (ssize_t)ret; + + mdelay(10); + + numwritten += ret; + buf += ret; + count -= ret; + offset += ret; + } + + return numwritten; +} + +static struct file_operations at24_fops = { + .lseek = dev_lseek_default, + .read = at24_read, + .write = at24_write, +}; + +static int at24_probe(struct device_d *dev) +{ + struct at24 *at24; + at24 = xzalloc(sizeof(*at24)); + + dev->priv = at24; + + at24->cdev.name = DRIVERNAME; + at24->client = to_i2c_client(dev); + at24->cdev.size = 256; + at24->cdev.dev = dev; + at24->cdev.ops = &at24_fops; + + devfs_create(&at24->cdev); + + return 0; +} + +static struct driver_d at24_driver = { + .name = DRIVERNAME, + .probe = at24_probe, +}; + +static int at24_init(void) +{ + register_driver(&at24_driver); + return 0; +} + +device_initcall(at24_init); -- 1.7.7 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
