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3fed7dbe JH |
1 | /* |
2 | * ImgTec IR Raw Decoder found in PowerDown Controller. | |
3 | * | |
4 | * Copyright 2010-2014 Imagination Technologies Ltd. | |
5 | * | |
2ac6f630 JH |
6 | * This program is free software; you can redistribute it and/or modify |
7 | * it under the terms of the GNU General Public License as published by the | |
8 | * Free Software Foundation; either version 2 of the License, or (at your | |
9 | * option) any later version. | |
10 | * | |
3fed7dbe JH |
11 | * This ties into the input subsystem using the RC-core in raw mode. Raw IR |
12 | * signal edges are reported and decoded by generic software decoders. | |
13 | */ | |
14 | ||
15 | #include <linux/spinlock.h> | |
16 | #include <media/rc-core.h> | |
17 | #include "img-ir.h" | |
18 | ||
19 | #define ECHO_TIMEOUT_MS 150 /* ms between echos */ | |
20 | ||
21 | /* must be called with priv->lock held */ | |
22 | static void img_ir_refresh_raw(struct img_ir_priv *priv, u32 irq_status) | |
23 | { | |
24 | struct img_ir_priv_raw *raw = &priv->raw; | |
25 | struct rc_dev *rc_dev = priv->raw.rdev; | |
26 | int multiple; | |
27 | u32 ir_status; | |
28 | ||
29 | /* find whether both rise and fall was detected */ | |
30 | multiple = ((irq_status & IMG_IR_IRQ_EDGE) == IMG_IR_IRQ_EDGE); | |
31 | /* | |
32 | * If so, we need to see if the level has actually changed. | |
33 | * If it's just noise that we didn't have time to process, | |
34 | * there's no point reporting it. | |
35 | */ | |
36 | ir_status = img_ir_read(priv, IMG_IR_STATUS) & IMG_IR_IRRXD; | |
37 | if (multiple && ir_status == raw->last_status) | |
38 | return; | |
39 | raw->last_status = ir_status; | |
40 | ||
41 | /* report the edge to the IR raw decoders */ | |
42 | if (ir_status) /* low */ | |
43 | ir_raw_event_store_edge(rc_dev, IR_SPACE); | |
44 | else /* high */ | |
45 | ir_raw_event_store_edge(rc_dev, IR_PULSE); | |
46 | ir_raw_event_handle(rc_dev); | |
47 | } | |
48 | ||
49 | /* called with priv->lock held */ | |
50 | void img_ir_isr_raw(struct img_ir_priv *priv, u32 irq_status) | |
51 | { | |
52 | struct img_ir_priv_raw *raw = &priv->raw; | |
53 | ||
54 | /* check not removing */ | |
55 | if (!raw->rdev) | |
56 | return; | |
57 | ||
58 | img_ir_refresh_raw(priv, irq_status); | |
59 | ||
60 | /* start / push back the echo timer */ | |
61 | mod_timer(&raw->timer, jiffies + msecs_to_jiffies(ECHO_TIMEOUT_MS)); | |
62 | } | |
63 | ||
64 | /* | |
65 | * Echo timer callback function. | |
66 | * The raw decoders expect to get a final sample even if there are no edges, in | |
67 | * order to be assured of the final space. If there are no edges for a certain | |
68 | * time we use this timer to emit a final sample to satisfy them. | |
69 | */ | |
70 | static void img_ir_echo_timer(unsigned long arg) | |
71 | { | |
72 | struct img_ir_priv *priv = (struct img_ir_priv *)arg; | |
73 | ||
74 | spin_lock_irq(&priv->lock); | |
75 | ||
76 | /* check not removing */ | |
77 | if (priv->raw.rdev) | |
78 | /* | |
79 | * It's safe to pass irq_status=0 since it's only used to check | |
80 | * for double edges. | |
81 | */ | |
82 | img_ir_refresh_raw(priv, 0); | |
83 | ||
84 | spin_unlock_irq(&priv->lock); | |
85 | } | |
86 | ||
87 | void img_ir_setup_raw(struct img_ir_priv *priv) | |
88 | { | |
89 | u32 irq_en; | |
90 | ||
91 | if (!priv->raw.rdev) | |
92 | return; | |
93 | ||
94 | /* clear and enable edge interrupts */ | |
95 | spin_lock_irq(&priv->lock); | |
96 | irq_en = img_ir_read(priv, IMG_IR_IRQ_ENABLE); | |
97 | irq_en |= IMG_IR_IRQ_EDGE; | |
98 | img_ir_write(priv, IMG_IR_IRQ_CLEAR, IMG_IR_IRQ_EDGE); | |
99 | img_ir_write(priv, IMG_IR_IRQ_ENABLE, irq_en); | |
100 | spin_unlock_irq(&priv->lock); | |
101 | } | |
102 | ||
103 | int img_ir_probe_raw(struct img_ir_priv *priv) | |
104 | { | |
105 | struct img_ir_priv_raw *raw = &priv->raw; | |
106 | struct rc_dev *rdev; | |
107 | int error; | |
108 | ||
109 | /* Set up the echo timer */ | |
110 | setup_timer(&raw->timer, img_ir_echo_timer, (unsigned long)priv); | |
111 | ||
112 | /* Allocate raw decoder */ | |
113 | raw->rdev = rdev = rc_allocate_device(); | |
114 | if (!rdev) { | |
115 | dev_err(priv->dev, "cannot allocate raw input device\n"); | |
116 | return -ENOMEM; | |
117 | } | |
118 | rdev->priv = priv; | |
119 | rdev->map_name = RC_MAP_EMPTY; | |
120 | rdev->input_name = "IMG Infrared Decoder Raw"; | |
121 | rdev->driver_type = RC_DRIVER_IR_RAW; | |
122 | ||
123 | /* Register raw decoder */ | |
124 | error = rc_register_device(rdev); | |
125 | if (error) { | |
126 | dev_err(priv->dev, "failed to register raw IR input device\n"); | |
127 | rc_free_device(rdev); | |
128 | raw->rdev = NULL; | |
129 | return error; | |
130 | } | |
131 | ||
132 | return 0; | |
133 | } | |
134 | ||
135 | void img_ir_remove_raw(struct img_ir_priv *priv) | |
136 | { | |
137 | struct img_ir_priv_raw *raw = &priv->raw; | |
138 | struct rc_dev *rdev = raw->rdev; | |
139 | u32 irq_en; | |
140 | ||
141 | if (!rdev) | |
142 | return; | |
143 | ||
144 | /* switch off and disable raw (edge) interrupts */ | |
145 | spin_lock_irq(&priv->lock); | |
146 | raw->rdev = NULL; | |
147 | irq_en = img_ir_read(priv, IMG_IR_IRQ_ENABLE); | |
148 | irq_en &= ~IMG_IR_IRQ_EDGE; | |
149 | img_ir_write(priv, IMG_IR_IRQ_ENABLE, irq_en); | |
150 | img_ir_write(priv, IMG_IR_IRQ_CLEAR, IMG_IR_IRQ_EDGE); | |
151 | spin_unlock_irq(&priv->lock); | |
152 | ||
153 | rc_unregister_device(rdev); | |
154 | ||
155 | del_timer_sync(&raw->timer); | |
156 | } |