diff options
author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-24 21:22:33 +0100 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-09-24 21:22:33 +0100 |
commit | baea7b946f00a291b166ccae7fcfed6c01530cc6 (patch) | |
tree | 4aa275fbdbec9c7b9b4629e8bee2bbecd3c6a6af /drivers/mfd/wm831x-otp.c | |
parent | ae19ffbadc1b2100285a5b5b3d0a4e0a11390904 (diff) | |
parent | 94e0fb086fc5663c38bbc0fe86d698be8314f82f (diff) |
Merge branch 'origin' into for-linus
Conflicts:
MAINTAINERS
Diffstat (limited to 'drivers/mfd/wm831x-otp.c')
-rw-r--r-- | drivers/mfd/wm831x-otp.c | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/drivers/mfd/wm831x-otp.c b/drivers/mfd/wm831x-otp.c new file mode 100644 index 00000000000..f742745ff35 --- /dev/null +++ b/drivers/mfd/wm831x-otp.c @@ -0,0 +1,83 @@ +/* + * wm831x-otp.c -- OTP for Wolfson WM831x PMICs + * + * Copyright 2009 Wolfson Microelectronics PLC. + * + * Author: Mark Brown <broonie@opensource.wolfsonmicro.com> + * + * 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/module.h> +#include <linux/i2c.h> +#include <linux/bcd.h> +#include <linux/delay.h> +#include <linux/mfd/core.h> + +#include <linux/mfd/wm831x/core.h> +#include <linux/mfd/wm831x/otp.h> + +/* In bytes */ +#define WM831X_UNIQUE_ID_LEN 16 + +/* Read the unique ID from the chip into id */ +static int wm831x_unique_id_read(struct wm831x *wm831x, char *id) +{ + int i, val; + + for (i = 0; i < WM831X_UNIQUE_ID_LEN / 2; i++) { + val = wm831x_reg_read(wm831x, WM831X_UNIQUE_ID_1 + i); + if (val < 0) + return val; + + id[i * 2] = (val >> 8) & 0xff; + id[(i * 2) + 1] = val & 0xff; + } + + return 0; +} + +static ssize_t wm831x_unique_id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct wm831x *wm831x = dev_get_drvdata(dev); + int i, rval; + char id[WM831X_UNIQUE_ID_LEN]; + ssize_t ret = 0; + + rval = wm831x_unique_id_read(wm831x, id); + if (rval < 0) + return 0; + + for (i = 0; i < WM831X_UNIQUE_ID_LEN; i++) + ret += sprintf(&buf[ret], "%02x", buf[i]); + + ret += sprintf(&buf[ret], "\n"); + + return ret; +} + +static DEVICE_ATTR(unique_id, 0444, wm831x_unique_id_show, NULL); + +int wm831x_otp_init(struct wm831x *wm831x) +{ + int ret; + + ret = device_create_file(wm831x->dev, &dev_attr_unique_id); + if (ret != 0) + dev_err(wm831x->dev, "Unique ID attribute not created: %d\n", + ret); + + return ret; +} + +void wm831x_otp_exit(struct wm831x *wm831x) +{ + device_remove_file(wm831x->dev, &dev_attr_unique_id); +} + |