2 * wm831x-otp.c -- OTP for Wolfson WM831x PMICs
4 * Copyright 2009 Wolfson Microelectronics PLC.
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/i2c.h>
18 #include <linux/bcd.h>
19 #include <linux/delay.h>
20 #include <linux/mfd/core.h>
22 #include <linux/mfd/wm831x/core.h>
23 #include <linux/mfd/wm831x/otp.h>
26 #define WM831X_UNIQUE_ID_LEN 16
28 /* Read the unique ID from the chip into id */
29 static int wm831x_unique_id_read(struct wm831x
*wm831x
, char *id
)
33 for (i
= 0; i
< WM831X_UNIQUE_ID_LEN
/ 2; i
++) {
34 val
= wm831x_reg_read(wm831x
, WM831X_UNIQUE_ID_1
+ i
);
38 id
[i
* 2] = (val
>> 8) & 0xff;
39 id
[(i
* 2) + 1] = val
& 0xff;
45 static ssize_t
wm831x_unique_id_show(struct device
*dev
,
46 struct device_attribute
*attr
, char *buf
)
48 struct wm831x
*wm831x
= dev_get_drvdata(dev
);
50 char id
[WM831X_UNIQUE_ID_LEN
];
53 rval
= wm831x_unique_id_read(wm831x
, id
);
57 for (i
= 0; i
< WM831X_UNIQUE_ID_LEN
; i
++)
58 ret
+= sprintf(&buf
[ret
], "%02x", buf
[i
]);
60 ret
+= sprintf(&buf
[ret
], "\n");
65 static DEVICE_ATTR(unique_id
, 0444, wm831x_unique_id_show
, NULL
);
67 int wm831x_otp_init(struct wm831x
*wm831x
)
71 ret
= device_create_file(wm831x
->dev
, &dev_attr_unique_id
);
73 dev_err(wm831x
->dev
, "Unique ID attribute not created: %d\n",
79 void wm831x_otp_exit(struct wm831x
*wm831x
)
81 device_remove_file(wm831x
->dev
, &dev_attr_unique_id
);
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