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49ef7925 OC |
1 | /* |
2 | * rl6231.c - RL6231 class device shared support | |
3 | * | |
4 | * Copyright 2014 Realtek Semiconductor Corp. | |
5 | * | |
6 | * Author: Oder Chiou <oder_chiou@realtek.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/moduleparam.h> | |
15 | #include <linux/init.h> | |
16 | #include <linux/delay.h> | |
17 | #include <linux/pm.h> | |
18 | #include <linux/gpio.h> | |
19 | #include <linux/i2c.h> | |
20 | #include <linux/regmap.h> | |
21 | #include <linux/of.h> | |
22 | #include <linux/of_gpio.h> | |
23 | #include <linux/platform_device.h> | |
24 | #include <linux/spi/spi.h> | |
25 | #include <linux/acpi.h> | |
26 | #include <sound/core.h> | |
27 | #include <sound/pcm.h> | |
28 | #include <sound/pcm_params.h> | |
29 | #include <sound/soc.h> | |
30 | #include <sound/soc-dapm.h> | |
31 | #include <sound/initval.h> | |
32 | #include <sound/tlv.h> | |
33 | ||
34 | #include "rl6231.h" | |
35 | ||
36 | /** | |
37 | * rl6231_calc_dmic_clk - Calculate the parameter of dmic. | |
38 | * | |
39 | * @rate: base clock rate. | |
40 | * | |
41 | * Choose dmic clock between 1MHz and 3MHz. | |
42 | * It is better for clock to approximate 3MHz. | |
43 | */ | |
44 | int rl6231_calc_dmic_clk(int rate) | |
45 | { | |
46 | int div[] = {2, 3, 4, 6, 8, 12}, idx = -EINVAL; | |
47 | int i, red, bound, temp; | |
48 | ||
49 | red = 3000000 * 12; | |
50 | for (i = 0; i < ARRAY_SIZE(div); i++) { | |
51 | bound = div[i] * 3000000; | |
52 | if (rate > bound) | |
53 | continue; | |
54 | temp = bound - rate; | |
55 | if (temp < red) { | |
56 | red = temp; | |
57 | idx = i; | |
58 | } | |
59 | } | |
60 | ||
61 | return idx; | |
62 | } | |
63 | EXPORT_SYMBOL_GPL(rl6231_calc_dmic_clk); | |
64 | ||
65 | MODULE_DESCRIPTION("RL6231 class device shared support"); | |
66 | MODULE_AUTHOR("Oder Chiou <oder_chiou@realtek.com>"); | |
67 | MODULE_LICENSE("GPL v2"); |