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420818f9 AH |
1 | /* drivers/input/misc/gpio_axis.c |
2 | * | |
3 | * Copyright (C) 2007 Google, Inc. | |
4 | * | |
5 | * This software is licensed under the terms of the GNU General Public | |
6 | * License version 2, as published by the Free Software Foundation, and | |
7 | * may be copied, distributed, and modified under those terms. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | */ | |
15 | ||
16 | #include <linux/kernel.h> | |
5a0e3ad6 | 17 | #include <linux/slab.h> |
420818f9 AH |
18 | #include <linux/gpio.h> |
19 | #include <linux/gpio_event.h> | |
20 | #include <linux/interrupt.h> | |
21 | ||
22 | struct gpio_axis_state { | |
23 | struct input_dev *input_dev; | |
24 | struct gpio_event_axis_info *info; | |
25 | uint32_t pos; | |
26 | }; | |
27 | ||
28 | uint16_t gpio_axis_4bit_gray_map_table[] = { | |
29 | [0x0] = 0x0, [0x1] = 0x1, /* 0000 0001 */ | |
30 | [0x3] = 0x2, [0x2] = 0x3, /* 0011 0010 */ | |
31 | [0x6] = 0x4, [0x7] = 0x5, /* 0110 0111 */ | |
32 | [0x5] = 0x6, [0x4] = 0x7, /* 0101 0100 */ | |
33 | [0xc] = 0x8, [0xd] = 0x9, /* 1100 1101 */ | |
34 | [0xf] = 0xa, [0xe] = 0xb, /* 1111 1110 */ | |
35 | [0xa] = 0xc, [0xb] = 0xd, /* 1010 1011 */ | |
36 | [0x9] = 0xe, [0x8] = 0xf, /* 1001 1000 */ | |
37 | }; | |
38 | uint16_t gpio_axis_4bit_gray_map(struct gpio_event_axis_info *info, uint16_t in) | |
39 | { | |
40 | return gpio_axis_4bit_gray_map_table[in]; | |
41 | } | |
42 | ||
43 | uint16_t gpio_axis_5bit_singletrack_map_table[] = { | |
44 | [0x10] = 0x00, [0x14] = 0x01, [0x1c] = 0x02, /* 10000 10100 11100 */ | |
45 | [0x1e] = 0x03, [0x1a] = 0x04, [0x18] = 0x05, /* 11110 11010 11000 */ | |
46 | [0x08] = 0x06, [0x0a] = 0x07, [0x0e] = 0x08, /* 01000 01010 01110 */ | |
47 | [0x0f] = 0x09, [0x0d] = 0x0a, [0x0c] = 0x0b, /* 01111 01101 01100 */ | |
48 | [0x04] = 0x0c, [0x05] = 0x0d, [0x07] = 0x0e, /* 00100 00101 00111 */ | |
49 | [0x17] = 0x0f, [0x16] = 0x10, [0x06] = 0x11, /* 10111 10110 00110 */ | |
50 | [0x02] = 0x12, [0x12] = 0x13, [0x13] = 0x14, /* 00010 10010 10011 */ | |
51 | [0x1b] = 0x15, [0x0b] = 0x16, [0x03] = 0x17, /* 11011 01011 00011 */ | |
52 | [0x01] = 0x18, [0x09] = 0x19, [0x19] = 0x1a, /* 00001 01001 11001 */ | |
53 | [0x1d] = 0x1b, [0x15] = 0x1c, [0x11] = 0x1d, /* 11101 10101 10001 */ | |
54 | }; | |
55 | uint16_t gpio_axis_5bit_singletrack_map( | |
56 | struct gpio_event_axis_info *info, uint16_t in) | |
57 | { | |
58 | return gpio_axis_5bit_singletrack_map_table[in]; | |
59 | } | |
60 | ||
61 | static void gpio_event_update_axis(struct gpio_axis_state *as, int report) | |
62 | { | |
63 | struct gpio_event_axis_info *ai = as->info; | |
64 | int i; | |
65 | int change; | |
66 | uint16_t state = 0; | |
67 | uint16_t pos; | |
68 | uint16_t old_pos = as->pos; | |
69 | for (i = ai->count - 1; i >= 0; i--) | |
70 | state = (state << 1) | gpio_get_value(ai->gpio[i]); | |
71 | pos = ai->map(ai, state); | |
72 | if (ai->flags & GPIOEAF_PRINT_RAW) | |
73 | pr_info("axis %d-%d raw %x, pos %d -> %d\n", | |
74 | ai->type, ai->code, state, old_pos, pos); | |
75 | if (report && pos != old_pos) { | |
76 | if (ai->type == EV_REL) { | |
77 | change = (ai->decoded_size + pos - old_pos) % | |
78 | ai->decoded_size; | |
79 | if (change > ai->decoded_size / 2) | |
80 | change -= ai->decoded_size; | |
81 | if (change == ai->decoded_size / 2) { | |
82 | if (ai->flags & GPIOEAF_PRINT_EVENT) | |
83 | pr_info("axis %d-%d unknown direction, " | |
84 | "pos %d -> %d\n", ai->type, | |
85 | ai->code, old_pos, pos); | |
86 | change = 0; /* no closest direction */ | |
87 | } | |
88 | if (ai->flags & GPIOEAF_PRINT_EVENT) | |
89 | pr_info("axis %d-%d change %d\n", | |
90 | ai->type, ai->code, change); | |
91 | input_report_rel(as->input_dev, ai->code, change); | |
92 | } else { | |
93 | if (ai->flags & GPIOEAF_PRINT_EVENT) | |
94 | pr_info("axis %d-%d now %d\n", | |
95 | ai->type, ai->code, pos); | |
96 | input_event(as->input_dev, ai->type, ai->code, pos); | |
97 | } | |
98 | input_sync(as->input_dev); | |
99 | } | |
100 | as->pos = pos; | |
101 | } | |
102 | ||
103 | static irqreturn_t gpio_axis_irq_handler(int irq, void *dev_id) | |
104 | { | |
105 | struct gpio_axis_state *as = dev_id; | |
106 | gpio_event_update_axis(as, 1); | |
107 | return IRQ_HANDLED; | |
108 | } | |
109 | ||
110 | int gpio_event_axis_func(struct input_dev *input_dev, | |
111 | struct gpio_event_info *info, void **data, int func) | |
112 | { | |
113 | int ret; | |
114 | int i; | |
115 | int irq; | |
116 | struct gpio_event_axis_info *ai; | |
117 | struct gpio_axis_state *as; | |
118 | ||
119 | ai = container_of(info, struct gpio_event_axis_info, info); | |
120 | if (func == GPIO_EVENT_FUNC_SUSPEND) { | |
121 | for (i = 0; i < ai->count; i++) | |
122 | disable_irq(gpio_to_irq(ai->gpio[i])); | |
123 | return 0; | |
124 | } | |
125 | if (func == GPIO_EVENT_FUNC_RESUME) { | |
126 | for (i = 0; i < ai->count; i++) | |
127 | enable_irq(gpio_to_irq(ai->gpio[i])); | |
128 | return 0; | |
129 | } | |
130 | ||
131 | if (func == GPIO_EVENT_FUNC_INIT) { | |
132 | *data = as = kmalloc(sizeof(*as), GFP_KERNEL); | |
133 | if (as == NULL) { | |
134 | ret = -ENOMEM; | |
135 | goto err_alloc_axis_state_failed; | |
136 | } | |
137 | as->input_dev = input_dev; | |
138 | as->info = ai; | |
139 | ||
140 | input_set_capability(input_dev, ai->type, ai->code); | |
141 | if (ai->type == EV_ABS) { | |
142 | input_set_abs_params(input_dev, ai->code, 0, | |
143 | ai->decoded_size - 1, 0, 0); | |
144 | } | |
145 | for (i = 0; i < ai->count; i++) { | |
146 | ret = gpio_request(ai->gpio[i], "gpio_event_axis"); | |
147 | if (ret < 0) | |
148 | goto err_request_gpio_failed; | |
149 | ret = gpio_direction_input(ai->gpio[i]); | |
150 | if (ret < 0) | |
151 | goto err_gpio_direction_input_failed; | |
152 | ret = irq = gpio_to_irq(ai->gpio[i]); | |
153 | if (ret < 0) | |
154 | goto err_get_irq_num_failed; | |
155 | ret = request_irq(irq, gpio_axis_irq_handler, | |
156 | IRQF_TRIGGER_RISING | | |
157 | IRQF_TRIGGER_FALLING, | |
158 | "gpio_event_axis", as); | |
159 | if (ret < 0) | |
160 | goto err_request_irq_failed; | |
161 | } | |
162 | gpio_event_update_axis(as, 0); | |
163 | return 0; | |
164 | } | |
165 | ||
166 | ret = 0; | |
167 | as = *data; | |
168 | for (i = ai->count - 1; i >= 0; i--) { | |
169 | free_irq(gpio_to_irq(ai->gpio[i]), as); | |
170 | err_request_irq_failed: | |
171 | err_get_irq_num_failed: | |
172 | err_gpio_direction_input_failed: | |
173 | gpio_free(ai->gpio[i]); | |
174 | err_request_gpio_failed: | |
175 | ; | |
176 | } | |
177 | kfree(as); | |
178 | *data = NULL; | |
179 | err_alloc_axis_state_failed: | |
180 | return ret; | |
181 | } |