diff --git a/drivers/eeprom/at24.c b/drivers/eeprom/at24.c index bb2dd53..76f30e7 100644 --- a/drivers/eeprom/at24.c +++ b/drivers/eeprom/at24.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include /* * I2C EEPROMs from most vendors are inexpensive and mostly interchangeable. @@ -55,6 +57,8 @@ u8 *writebuf; unsigned write_max; unsigned num_addresses; + int wp_gpio; + int wp_active_low; /* * Some chips tie up multiple I2C addresses; dummy devices reserve @@ -345,6 +349,25 @@ return at24_write(at24, buf, off, count); } +static ssize_t at24_cdev_protect(struct cdev *cdev, size_t count, loff_t offset, + int prot) +{ + struct at24_data *at24 = cdev->priv; + + if (!gpio_is_valid(at24->wp_gpio)) + return -EOPNOTSUPP; + + prot = !!prot; + if (at24->wp_active_low) + prot = !prot; + + gpio_set_value(at24->wp_gpio, prot); + + udelay(50); + + return 0; +} + static int at24_probe(struct device_d *dev) { struct i2c_client *client = to_i2c_client(dev); @@ -403,6 +426,7 @@ at24->cdev.ops = &at24->fops; at24->fops.lseek = dev_lseek_default; at24->fops.read = at24_cdev_read, + at24->fops.protect = at24_cdev_protect, at24->cdev.size = chip.byte_len; writable = !(chip.flags & AT24_FLAG_READONLY); @@ -419,6 +443,19 @@ at24->writebuf = xmalloc(write_max + 2); } + at24->wp_gpio = -1; + if (dev->device_node) { + enum of_gpio_flags flags; + at24->wp_gpio = of_get_named_gpio_flags(dev->device_node, + "wp-gpios", 0, &flags); + if (gpio_is_valid(at24->wp_gpio)) { + at24->wp_active_low = flags & OF_GPIO_ACTIVE_LOW; + gpio_request(at24->wp_gpio, "eeprom-wp"); + gpio_direction_output(at24->wp_gpio, + !at24->wp_active_low); + } + } + at24->client[0] = client; /* use dummy devices for multiple-address chips */ @@ -440,6 +477,7 @@ return 0; err_clients: + gpio_free(at24->wp_gpio); kfree(at24->writebuf); kfree(at24); err_out: