diff options
Diffstat (limited to 'firmware/target/arm/imx233')
-rw-r--r-- | firmware/target/arm/imx233/button-lradc-imx233.c | 122 | ||||
-rw-r--r-- | firmware/target/arm/imx233/button-lradc-imx233.h | 56 |
2 files changed, 178 insertions, 0 deletions
diff --git a/firmware/target/arm/imx233/button-lradc-imx233.c b/firmware/target/arm/imx233/button-lradc-imx233.c new file mode 100644 index 0000000000..66d42a47dc --- /dev/null +++ b/firmware/target/arm/imx233/button-lradc-imx233.c | |||
@@ -0,0 +1,122 @@ | |||
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 | #include "button-lradc-imx233.h" | ||
22 | #include "stdlib.h" | ||
23 | #include "lradc-imx233.h" | ||
24 | |||
25 | #ifndef IMX233_BUTTON_LRADC_CHANNEL | ||
26 | #error You must define IMX233_BUTTON_LRADC_CHANNEL to use button-lradc | ||
27 | #endif | ||
28 | |||
29 | /* physical channel */ | ||
30 | #define CHAN IMX233_BUTTON_LRADC_CHANNEL | ||
31 | /* number of irq per second */ | ||
32 | #ifdef IMX233_BUTTON_LRADC_RATE | ||
33 | # define RATE IMX233_BUTTON_LRADC_RATE | ||
34 | #else | ||
35 | # define RATE HZ | ||
36 | #endif | ||
37 | /* number of samples per irq */ | ||
38 | #ifdef IMX233_BUTTON_LRADC_SAMPLES | ||
39 | # define SAMPLES IMX233_BUTTON_LRADC_SAMPLES | ||
40 | #else | ||
41 | # define SAMPLES 10 | ||
42 | #endif | ||
43 | /* delay's delay */ | ||
44 | #define DELAY (LRADC_DELAY_FREQ / RATE / SAMPLES) | ||
45 | |||
46 | static int button_delay; | ||
47 | static int button_chan; | ||
48 | static int button_val[2]; | ||
49 | static int button_idx; | ||
50 | static int button_mask; | ||
51 | static int table_size; | ||
52 | |||
53 | static int button_find(int val) | ||
54 | { | ||
55 | // shortcuts | ||
56 | struct imx233_button_lradc_mapping_t *table = imx233_button_lradc_mapping; | ||
57 | /* FIXME use a dichotomy */ | ||
58 | int i = 0; | ||
59 | while(i < table_size && val >= table[i].adc_val) | ||
60 | i++; | ||
61 | // extreme cases | ||
62 | int btn = 0; | ||
63 | // if i=n then choose i-1 and otherwise choose best between i-1 and i | ||
64 | if(i == 0) | ||
65 | btn = table[0].btn; | ||
66 | else if(i == table_size) | ||
67 | btn = table[i - 1].btn; | ||
68 | // choose best between i-1 and i (note that table[i-1]<=val<=table[i]) */ | ||
69 | else if(val - table[i - 1].adc_val < table[i].adc_val - val) | ||
70 | btn = table[i - 1].btn; | ||
71 | else | ||
72 | btn = table[i].btn; | ||
73 | return btn; | ||
74 | } | ||
75 | |||
76 | int button_value; | ||
77 | |||
78 | static void button_lradc_irq(int chan) | ||
79 | { | ||
80 | (void) chan; | ||
81 | /* read value, kick channel */ | ||
82 | button_val[button_idx] = imx233_lradc_read_channel(button_chan) / SAMPLES; | ||
83 | imx233_lradc_clear_channel(button_chan); | ||
84 | imx233_lradc_setup_channel(button_chan, true, true, SAMPLES - 1, LRADC_SRC(CHAN)); | ||
85 | imx233_lradc_setup_delay(button_delay, 1 << button_chan, 0, SAMPLES - 1, DELAY); | ||
86 | imx233_lradc_kick_delay(button_delay); | ||
87 | button_value = button_val[button_idx]; | ||
88 | /* compute mask, compare to previous one */ | ||
89 | button_val[button_idx] = button_find(button_val[button_idx]); | ||
90 | button_idx = 1 - button_idx; | ||
91 | if(button_val[0] == button_val[1]) | ||
92 | button_mask = button_val[0]; | ||
93 | } | ||
94 | |||
95 | void imx233_button_lradc_init(void) | ||
96 | { | ||
97 | button_chan = imx233_lradc_acquire_channel(LRADC_SRC(CHAN), TIMEOUT_NOBLOCK); | ||
98 | if(button_chan < 0) | ||
99 | panicf("Cannot get channel for button-lradc"); | ||
100 | button_delay = imx233_lradc_acquire_delay(TIMEOUT_NOBLOCK); | ||
101 | if(button_delay < 0) | ||
102 | panicf("Cannot get delay for button-lradc"); | ||
103 | imx233_lradc_setup_channel(button_chan, true, true, SAMPLES - 1, LRADC_SRC(CHAN)); | ||
104 | imx233_lradc_setup_delay(button_delay, 1 << button_chan, 0, SAMPLES - 1, DELAY); | ||
105 | imx233_lradc_enable_channel_irq(button_chan, true); | ||
106 | imx233_lradc_set_channel_irq_callback(button_chan, button_lradc_irq); | ||
107 | imx233_lradc_kick_delay(button_delay); | ||
108 | |||
109 | table_size = 0; | ||
110 | while(imx233_button_lradc_mapping[table_size].btn != IMX233_BUTTON_LRADC_END) | ||
111 | table_size++; | ||
112 | } | ||
113 | |||
114 | bool imx233_button_lradc_hold(void) | ||
115 | { | ||
116 | return button_mask == IMX233_BUTTON_LRADC_HOLD; | ||
117 | } | ||
118 | |||
119 | int imx233_button_lradc_read(void) | ||
120 | { | ||
121 | return button_mask == IMX233_BUTTON_LRADC_HOLD ? 0 : button_mask; | ||
122 | } | ||
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__ */ | ||