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author | Amaury Pouly <amaury.pouly@gmail.com> | 2013-06-18 16:43:27 +0200 |
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committer | Amaury Pouly <amaury.pouly@gmail.com> | 2013-06-18 16:43:27 +0200 |
commit | 277d358eda7f7571450e09c615c8aaf67d7b4693 (patch) | |
tree | e05317e65831d8d892efbff7b533b4f77ac969df /firmware/target/arm/imx233/button-lradc-imx233.h | |
parent | 27aca8f2761a0715061e893cbf70f172dbd8e2bb (diff) | |
download | rockbox-277d358eda7f7571450e09c615c8aaf67d7b4693.tar.gz rockbox-277d358eda7f7571450e09c615c8aaf67d7b4693.zip |
imx233: add generic lradc based button driver
This driver does debouncing and best lradc usage and only requires
a sorted table of values to work, this factoring code as much as
possible.
Change-Id: I84b46f4b08094634e1c5deb5ca9ba20763389e66
Diffstat (limited to 'firmware/target/arm/imx233/button-lradc-imx233.h')
-rw-r--r-- | firmware/target/arm/imx233/button-lradc-imx233.h | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/firmware/target/arm/imx233/button-lradc-imx233.h b/firmware/target/arm/imx233/button-lradc-imx233.h new file mode 100644 index 0000000000..d3e6ad8326 --- /dev/null +++ b/firmware/target/arm/imx233/button-lradc-imx233.h | |||
@@ -0,0 +1,56 @@ | |||
1 | /*************************************************************************** | ||
2 | * __________ __ ___. | ||
3 | * Open \______ \ ____ ____ | | _\_ |__ _______ ___ | ||
4 | * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / | ||
5 | * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < | ||
6 | * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ | ||
7 | * \/ \/ \/ \/ \/ | ||
8 | * $Id$ | ||
9 | * | ||
10 | * Copyright (C) 2013 by Amaury Pouly | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version 2 | ||
15 | * of the License, or (at your option) any later version. | ||
16 | * | ||
17 | * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY | ||
18 | * KIND, either express or implied. | ||
19 | * | ||
20 | ****************************************************************************/ | ||
21 | #ifndef __button_lradc_imx233__ | ||
22 | #define __button_lradc_imx233__ | ||
23 | |||
24 | #include "button.h" | ||
25 | #include "button-target.h" | ||
26 | |||
27 | /** This driver implements button sensing with lradc. It does debouncing | ||
28 | * and can handle hold sensing too. It can be tweaked using the following defines | ||
29 | * and variables: | ||
30 | * - imx233_button_lradc_mapping: target-defined table of adc values and mapping | ||
31 | * - IMX233_BUTTON_LRADC_CHANNEL: lradc channel to use | ||
32 | */ | ||
33 | |||
34 | /* special value for btn to handle HOLD */ | ||
35 | #define IMX233_BUTTON_LRADC_END -1 | ||
36 | #define IMX233_BUTTON_LRADC_HOLD -2 | ||
37 | |||
38 | struct imx233_button_lradc_mapping_t | ||
39 | { | ||
40 | int adc_val; | ||
41 | int btn; | ||
42 | }; | ||
43 | |||
44 | /* target-defined | ||
45 | * NOTE for proper operation, the table should contain entries for all states, including: | ||
46 | * - one with adc_val set to default value when no button is pressed | ||
47 | * - one with adc_val set to value when hold is selected (if hold is sensed using adc) | ||
48 | * - a dummy entry with btn set to IMX233_BUTTON_LRADC_END as the last entry | ||
49 | * The table must be sorted by increasing values of adc_val */ | ||
50 | extern struct imx233_button_lradc_mapping_t imx233_button_lradc_mapping[]; | ||
51 | |||
52 | void imx233_button_lradc_init(void); | ||
53 | int imx233_button_lradc_read(void); | ||
54 | bool imx233_button_lradc_hold(void); | ||
55 | |||
56 | #endif /* __button_lradc_imx233__ */ | ||