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40e3be39 DR |
1 | /* |
2 | * Touchscreen driver for the TS-4800 board | |
3 | * | |
4 | * Copyright (c) 2015 - Savoir-faire Linux | |
5 | * | |
6 | * This file is licensed under the terms of the GNU General Public | |
7 | * License version 2. This program is licensed "as is" without any | |
8 | * warranty of any kind, whether express or implied. | |
9 | */ | |
10 | ||
11 | #include <linux/bitops.h> | |
12 | #include <linux/input.h> | |
13 | #include <linux/input-polldev.h> | |
14 | #include <linux/io.h> | |
15 | #include <linux/kernel.h> | |
16 | #include <linux/mfd/syscon.h> | |
17 | #include <linux/module.h> | |
18 | #include <linux/of.h> | |
19 | #include <linux/platform_device.h> | |
20 | #include <linux/regmap.h> | |
21 | ||
22 | /* polling interval in ms */ | |
23 | #define POLL_INTERVAL 3 | |
24 | ||
25 | #define DEBOUNCE_COUNT 1 | |
26 | ||
27 | /* sensor values are 12-bit wide */ | |
28 | #define MAX_12BIT ((1 << 12) - 1) | |
29 | ||
30 | #define PENDOWN_MASK 0x1 | |
31 | ||
32 | #define X_OFFSET 0x0 | |
33 | #define Y_OFFSET 0x2 | |
34 | ||
35 | struct ts4800_ts { | |
36 | struct input_polled_dev *poll_dev; | |
37 | struct device *dev; | |
38 | char phys[32]; | |
39 | ||
40 | void __iomem *base; | |
41 | struct regmap *regmap; | |
42 | unsigned int reg; | |
43 | unsigned int bit; | |
44 | ||
45 | bool pendown; | |
46 | int debounce; | |
47 | }; | |
48 | ||
49 | static void ts4800_ts_open(struct input_polled_dev *dev) | |
50 | { | |
51 | struct ts4800_ts *ts = dev->private; | |
52 | int ret; | |
53 | ||
54 | ts->pendown = false; | |
55 | ts->debounce = DEBOUNCE_COUNT; | |
56 | ||
57 | ret = regmap_update_bits(ts->regmap, ts->reg, ts->bit, ts->bit); | |
58 | if (ret) | |
59 | dev_warn(ts->dev, "Failed to enable touchscreen\n"); | |
60 | } | |
61 | ||
62 | static void ts4800_ts_close(struct input_polled_dev *dev) | |
63 | { | |
64 | struct ts4800_ts *ts = dev->private; | |
65 | int ret; | |
66 | ||
67 | ret = regmap_update_bits(ts->regmap, ts->reg, ts->bit, 0); | |
68 | if (ret) | |
69 | dev_warn(ts->dev, "Failed to disable touchscreen\n"); | |
70 | ||
71 | } | |
72 | ||
73 | static void ts4800_ts_poll(struct input_polled_dev *dev) | |
74 | { | |
75 | struct input_dev *input_dev = dev->input; | |
76 | struct ts4800_ts *ts = dev->private; | |
77 | u16 last_x = readw(ts->base + X_OFFSET); | |
78 | u16 last_y = readw(ts->base + Y_OFFSET); | |
79 | bool pendown = last_x & PENDOWN_MASK; | |
80 | ||
81 | if (pendown) { | |
82 | if (ts->debounce) { | |
83 | ts->debounce--; | |
84 | return; | |
85 | } | |
86 | ||
87 | if (!ts->pendown) { | |
88 | input_report_key(input_dev, BTN_TOUCH, 1); | |
89 | ts->pendown = true; | |
90 | } | |
91 | ||
92 | last_x = ((~last_x) >> 4) & MAX_12BIT; | |
93 | last_y = ((~last_y) >> 4) & MAX_12BIT; | |
94 | ||
95 | input_report_abs(input_dev, ABS_X, last_x); | |
96 | input_report_abs(input_dev, ABS_Y, last_y); | |
97 | input_sync(input_dev); | |
98 | } else if (ts->pendown) { | |
99 | ts->pendown = false; | |
100 | ts->debounce = DEBOUNCE_COUNT; | |
101 | input_report_key(input_dev, BTN_TOUCH, 0); | |
102 | input_sync(input_dev); | |
103 | } | |
104 | } | |
105 | ||
106 | static int ts4800_parse_dt(struct platform_device *pdev, | |
107 | struct ts4800_ts *ts) | |
108 | { | |
109 | struct device *dev = &pdev->dev; | |
110 | struct device_node *np = dev->of_node; | |
111 | struct device_node *syscon_np; | |
112 | u32 reg, bit; | |
113 | int error; | |
114 | ||
115 | syscon_np = of_parse_phandle(np, "syscon", 0); | |
116 | if (!syscon_np) { | |
117 | dev_err(dev, "no syscon property\n"); | |
118 | return -ENODEV; | |
119 | } | |
120 | ||
6a5029e6 PC |
121 | ts->regmap = syscon_node_to_regmap(syscon_np); |
122 | of_node_put(syscon_np); | |
123 | if (IS_ERR(ts->regmap)) { | |
124 | dev_err(dev, "cannot get parent's regmap\n"); | |
125 | return PTR_ERR(ts->regmap); | |
126 | } | |
127 | ||
40e3be39 DR |
128 | error = of_property_read_u32_index(np, "syscon", 1, ®); |
129 | if (error < 0) { | |
130 | dev_err(dev, "no offset in syscon\n"); | |
131 | return error; | |
132 | } | |
133 | ||
134 | ts->reg = reg; | |
135 | ||
136 | error = of_property_read_u32_index(np, "syscon", 2, &bit); | |
137 | if (error < 0) { | |
138 | dev_err(dev, "no bit in syscon\n"); | |
139 | return error; | |
140 | } | |
141 | ||
142 | ts->bit = BIT(bit); | |
143 | ||
40e3be39 DR |
144 | return 0; |
145 | } | |
146 | ||
147 | static int ts4800_ts_probe(struct platform_device *pdev) | |
148 | { | |
149 | struct input_polled_dev *poll_dev; | |
150 | struct ts4800_ts *ts; | |
151 | struct resource *res; | |
152 | int error; | |
153 | ||
154 | ts = devm_kzalloc(&pdev->dev, sizeof(*ts), GFP_KERNEL); | |
155 | if (!ts) | |
156 | return -ENOMEM; | |
157 | ||
158 | error = ts4800_parse_dt(pdev, ts); | |
159 | if (error) | |
160 | return error; | |
161 | ||
162 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); | |
163 | ts->base = devm_ioremap_resource(&pdev->dev, res); | |
164 | if (IS_ERR(ts->base)) | |
165 | return PTR_ERR(ts->base); | |
166 | ||
167 | poll_dev = devm_input_allocate_polled_device(&pdev->dev); | |
168 | if (!poll_dev) | |
169 | return -ENOMEM; | |
170 | ||
171 | snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&pdev->dev)); | |
172 | ts->poll_dev = poll_dev; | |
173 | ts->dev = &pdev->dev; | |
174 | ||
175 | poll_dev->private = ts; | |
176 | poll_dev->poll_interval = POLL_INTERVAL; | |
177 | poll_dev->open = ts4800_ts_open; | |
178 | poll_dev->close = ts4800_ts_close; | |
179 | poll_dev->poll = ts4800_ts_poll; | |
180 | ||
181 | poll_dev->input->name = "TS-4800 Touchscreen"; | |
182 | poll_dev->input->phys = ts->phys; | |
183 | ||
184 | input_set_capability(poll_dev->input, EV_KEY, BTN_TOUCH); | |
185 | input_set_abs_params(poll_dev->input, ABS_X, 0, MAX_12BIT, 0, 0); | |
186 | input_set_abs_params(poll_dev->input, ABS_Y, 0, MAX_12BIT, 0, 0); | |
187 | ||
188 | error = input_register_polled_device(poll_dev); | |
189 | if (error) { | |
190 | dev_err(&pdev->dev, | |
191 | "Unabled to register polled input device (%d)\n", | |
192 | error); | |
193 | return error; | |
194 | } | |
195 | ||
196 | return 0; | |
197 | } | |
198 | ||
199 | static const struct of_device_id ts4800_ts_of_match[] = { | |
200 | { .compatible = "technologic,ts4800-ts", }, | |
201 | { }, | |
202 | }; | |
203 | MODULE_DEVICE_TABLE(of, ts4800_ts_of_match); | |
204 | ||
205 | static struct platform_driver ts4800_ts_driver = { | |
206 | .driver = { | |
207 | .name = "ts4800-ts", | |
208 | .of_match_table = ts4800_ts_of_match, | |
209 | }, | |
210 | .probe = ts4800_ts_probe, | |
211 | }; | |
212 | module_platform_driver(ts4800_ts_driver); | |
213 | ||
214 | MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>"); | |
215 | MODULE_DESCRIPTION("TS-4800 Touchscreen Driver"); | |
216 | MODULE_LICENSE("GPL v2"); | |
217 | MODULE_ALIAS("platform:ts4800_ts"); |