diff options
Diffstat (limited to 'drivers/input/misc/rotary_encoder.c')
-rw-r--r-- | drivers/input/misc/rotary_encoder.c | 119 |
1 files changed, 83 insertions, 36 deletions
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index 7e64d01da2be..2c8b84dd9dac 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c | |||
@@ -2,6 +2,7 @@ | |||
2 | * rotary_encoder.c | 2 | * rotary_encoder.c |
3 | * | 3 | * |
4 | * (c) 2009 Daniel Mack <daniel@caiaq.de> | 4 | * (c) 2009 Daniel Mack <daniel@caiaq.de> |
5 | * Copyright (C) 2011 Johan Hovold <jhovold@gmail.com> | ||
5 | * | 6 | * |
6 | * state machine code inspired by code from Tim Ruetz | 7 | * state machine code inspired by code from Tim Ruetz |
7 | * | 8 | * |
@@ -38,52 +39,66 @@ struct rotary_encoder { | |||
38 | 39 | ||
39 | bool armed; | 40 | bool armed; |
40 | unsigned char dir; /* 0 - clockwise, 1 - CCW */ | 41 | unsigned char dir; /* 0 - clockwise, 1 - CCW */ |
42 | |||
43 | char last_stable; | ||
41 | }; | 44 | }; |
42 | 45 | ||
43 | static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) | 46 | static int rotary_encoder_get_state(struct rotary_encoder_platform_data *pdata) |
44 | { | 47 | { |
45 | struct rotary_encoder *encoder = dev_id; | ||
46 | struct rotary_encoder_platform_data *pdata = encoder->pdata; | ||
47 | int a = !!gpio_get_value(pdata->gpio_a); | 48 | int a = !!gpio_get_value(pdata->gpio_a); |
48 | int b = !!gpio_get_value(pdata->gpio_b); | 49 | int b = !!gpio_get_value(pdata->gpio_b); |
49 | int state; | ||
50 | 50 | ||
51 | a ^= pdata->inverted_a; | 51 | a ^= pdata->inverted_a; |
52 | b ^= pdata->inverted_b; | 52 | b ^= pdata->inverted_b; |
53 | state = (a << 1) | b; | ||
54 | 53 | ||
55 | switch (state) { | 54 | return ((a << 1) | b); |
55 | } | ||
56 | 56 | ||
57 | case 0x0: | 57 | static void rotary_encoder_report_event(struct rotary_encoder *encoder) |
58 | if (!encoder->armed) | 58 | { |
59 | break; | 59 | struct rotary_encoder_platform_data *pdata = encoder->pdata; |
60 | 60 | ||
61 | if (pdata->relative_axis) { | 61 | if (pdata->relative_axis) { |
62 | input_report_rel(encoder->input, pdata->axis, | 62 | input_report_rel(encoder->input, |
63 | encoder->dir ? -1 : 1); | 63 | pdata->axis, encoder->dir ? -1 : 1); |
64 | } else { | 64 | } else { |
65 | unsigned int pos = encoder->pos; | 65 | unsigned int pos = encoder->pos; |
66 | 66 | ||
67 | if (encoder->dir) { | 67 | if (encoder->dir) { |
68 | /* turning counter-clockwise */ | 68 | /* turning counter-clockwise */ |
69 | if (pdata->rollover) | ||
70 | pos += pdata->steps; | ||
71 | if (pos) | ||
72 | pos--; | ||
73 | } else { | ||
74 | /* turning clockwise */ | ||
75 | if (pdata->rollover || pos < pdata->steps) | ||
76 | pos++; | ||
77 | } | ||
78 | if (pdata->rollover) | 69 | if (pdata->rollover) |
79 | pos %= pdata->steps; | 70 | pos += pdata->steps; |
80 | encoder->pos = pos; | 71 | if (pos) |
81 | input_report_abs(encoder->input, pdata->axis, | 72 | pos--; |
82 | encoder->pos); | 73 | } else { |
74 | /* turning clockwise */ | ||
75 | if (pdata->rollover || pos < pdata->steps) | ||
76 | pos++; | ||
83 | } | 77 | } |
84 | input_sync(encoder->input); | ||
85 | 78 | ||
86 | encoder->armed = false; | 79 | if (pdata->rollover) |
80 | pos %= pdata->steps; | ||
81 | |||
82 | encoder->pos = pos; | ||
83 | input_report_abs(encoder->input, pdata->axis, encoder->pos); | ||
84 | } | ||
85 | |||
86 | input_sync(encoder->input); | ||
87 | } | ||
88 | |||
89 | static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) | ||
90 | { | ||
91 | struct rotary_encoder *encoder = dev_id; | ||
92 | int state; | ||
93 | |||
94 | state = rotary_encoder_get_state(encoder->pdata); | ||
95 | |||
96 | switch (state) { | ||
97 | case 0x0: | ||
98 | if (encoder->armed) { | ||
99 | rotary_encoder_report_event(encoder); | ||
100 | encoder->armed = false; | ||
101 | } | ||
87 | break; | 102 | break; |
88 | 103 | ||
89 | case 0x1: | 104 | case 0x1: |
@@ -100,11 +115,37 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id) | |||
100 | return IRQ_HANDLED; | 115 | return IRQ_HANDLED; |
101 | } | 116 | } |
102 | 117 | ||
118 | static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id) | ||
119 | { | ||
120 | struct rotary_encoder *encoder = dev_id; | ||
121 | int state; | ||
122 | |||
123 | state = rotary_encoder_get_state(encoder->pdata); | ||
124 | |||
125 | switch (state) { | ||
126 | case 0x00: | ||
127 | case 0x03: | ||
128 | if (state != encoder->last_stable) { | ||
129 | rotary_encoder_report_event(encoder); | ||
130 | encoder->last_stable = state; | ||
131 | } | ||
132 | break; | ||
133 | |||
134 | case 0x01: | ||
135 | case 0x02: | ||
136 | encoder->dir = (encoder->last_stable + state) & 0x01; | ||
137 | break; | ||
138 | } | ||
139 | |||
140 | return IRQ_HANDLED; | ||
141 | } | ||
142 | |||
103 | static int __devinit rotary_encoder_probe(struct platform_device *pdev) | 143 | static int __devinit rotary_encoder_probe(struct platform_device *pdev) |
104 | { | 144 | { |
105 | struct rotary_encoder_platform_data *pdata = pdev->dev.platform_data; | 145 | struct rotary_encoder_platform_data *pdata = pdev->dev.platform_data; |
106 | struct rotary_encoder *encoder; | 146 | struct rotary_encoder *encoder; |
107 | struct input_dev *input; | 147 | struct input_dev *input; |
148 | irq_handler_t handler; | ||
108 | int err; | 149 | int err; |
109 | 150 | ||
110 | if (!pdata) { | 151 | if (!pdata) { |
@@ -175,7 +216,14 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) | |||
175 | } | 216 | } |
176 | 217 | ||
177 | /* request the IRQs */ | 218 | /* request the IRQs */ |
178 | err = request_irq(encoder->irq_a, &rotary_encoder_irq, | 219 | if (pdata->half_period) { |
220 | handler = &rotary_encoder_half_period_irq; | ||
221 | encoder->last_stable = rotary_encoder_get_state(pdata); | ||
222 | } else { | ||
223 | handler = &rotary_encoder_irq; | ||
224 | } | ||
225 | |||
226 | err = request_irq(encoder->irq_a, handler, | ||
179 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, | 227 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, |
180 | DRV_NAME, encoder); | 228 | DRV_NAME, encoder); |
181 | if (err) { | 229 | if (err) { |
@@ -184,7 +232,7 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev) | |||
184 | goto exit_free_gpio_b; | 232 | goto exit_free_gpio_b; |
185 | } | 233 | } |
186 | 234 | ||
187 | err = request_irq(encoder->irq_b, &rotary_encoder_irq, | 235 | err = request_irq(encoder->irq_b, handler, |
188 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, | 236 | IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING, |
189 | DRV_NAME, encoder); | 237 | DRV_NAME, encoder); |
190 | if (err) { | 238 | if (err) { |
@@ -252,6 +300,5 @@ module_exit(rotary_encoder_exit); | |||
252 | 300 | ||
253 | MODULE_ALIAS("platform:" DRV_NAME); | 301 | MODULE_ALIAS("platform:" DRV_NAME); |
254 | MODULE_DESCRIPTION("GPIO rotary encoder driver"); | 302 | MODULE_DESCRIPTION("GPIO rotary encoder driver"); |
255 | MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>"); | 303 | MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>, Johan Hovold"); |
256 | MODULE_LICENSE("GPL v2"); | 304 | MODULE_LICENSE("GPL v2"); |
257 | |||