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9#include <linux/io.h>
10#include <linux/of.h>
11#include <linux/slab.h>
12#include <linux/device.h>
13#include <linux/module.h>
14#include <linux/bitops.h>
15#include <linux/dma-mapping.h>
16#include <linux/platform_device.h>
17#include <linux/input.h>
18#include <linux/input/mt.h>
19#include <linux/input/touchscreen.h>
20#include <soc/bcm2835/raspberrypi-firmware.h>
21
22#define RPI_TS_DEFAULT_WIDTH 800
23#define RPI_TS_DEFAULT_HEIGHT 480
24
25#define RPI_TS_MAX_SUPPORTED_POINTS 10
26
27#define RPI_TS_FTS_TOUCH_DOWN 0
28#define RPI_TS_FTS_TOUCH_CONTACT 2
29
30#define RPI_TS_POLL_INTERVAL 17
31
32#define RPI_TS_NPOINTS_REG_INVALIDATE 99
33
34struct rpi_ts {
35 struct platform_device *pdev;
36 struct input_dev *input;
37 struct touchscreen_properties prop;
38
39 void __iomem *fw_regs_va;
40 dma_addr_t fw_regs_phys;
41
42 int known_ids;
43};
44
45struct rpi_ts_regs {
46 u8 device_mode;
47 u8 gesture_id;
48 u8 num_points;
49 struct rpi_ts_touch {
50 u8 xh;
51 u8 xl;
52 u8 yh;
53 u8 yl;
54 u8 pressure;
55 u8 area;
56 } point[RPI_TS_MAX_SUPPORTED_POINTS];
57};
58
59static void rpi_ts_poll(struct input_dev *input)
60{
61 struct rpi_ts *ts = input_get_drvdata(input);
62 struct rpi_ts_regs regs;
63 int modified_ids = 0;
64 long released_ids;
65 int event_type;
66 int touchid;
67 int x, y;
68 int i;
69
70 memcpy_fromio(®s, ts->fw_regs_va, sizeof(regs));
71
72
73
74
75
76
77 iowrite8(RPI_TS_NPOINTS_REG_INVALIDATE,
78 ts->fw_regs_va + offsetof(struct rpi_ts_regs, num_points));
79
80 if (regs.num_points == RPI_TS_NPOINTS_REG_INVALIDATE ||
81 (regs.num_points == 0 && ts->known_ids == 0))
82 return;
83
84 for (i = 0; i < regs.num_points; i++) {
85 x = (((int)regs.point[i].xh & 0xf) << 8) + regs.point[i].xl;
86 y = (((int)regs.point[i].yh & 0xf) << 8) + regs.point[i].yl;
87 touchid = (regs.point[i].yh >> 4) & 0xf;
88 event_type = (regs.point[i].xh >> 6) & 0x03;
89
90 modified_ids |= BIT(touchid);
91
92 if (event_type == RPI_TS_FTS_TOUCH_DOWN ||
93 event_type == RPI_TS_FTS_TOUCH_CONTACT) {
94 input_mt_slot(input, touchid);
95 input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
96 touchscreen_report_pos(input, &ts->prop, x, y, true);
97 }
98 }
99
100 released_ids = ts->known_ids & ~modified_ids;
101 for_each_set_bit(i, &released_ids, RPI_TS_MAX_SUPPORTED_POINTS) {
102 input_mt_slot(input, i);
103 input_mt_report_slot_state(input, MT_TOOL_FINGER, 0);
104 modified_ids &= ~(BIT(i));
105 }
106 ts->known_ids = modified_ids;
107
108 input_mt_sync_frame(input);
109 input_sync(input);
110}
111
112static void rpi_ts_dma_cleanup(void *data)
113{
114 struct rpi_ts *ts = data;
115 struct device *dev = &ts->pdev->dev;
116
117 dma_free_coherent(dev, PAGE_SIZE, ts->fw_regs_va, ts->fw_regs_phys);
118}
119
120static int rpi_ts_probe(struct platform_device *pdev)
121{
122 struct device *dev = &pdev->dev;
123 struct device_node *np = dev->of_node;
124 struct input_dev *input;
125 struct device_node *fw_node;
126 struct rpi_firmware *fw;
127 struct rpi_ts *ts;
128 u32 touchbuf;
129 int error;
130
131 fw_node = of_get_parent(np);
132 if (!fw_node) {
133 dev_err(dev, "Missing firmware node\n");
134 return -ENOENT;
135 }
136
137 fw = rpi_firmware_get(fw_node);
138 of_node_put(fw_node);
139 if (!fw)
140 return -EPROBE_DEFER;
141
142 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
143 if (!ts)
144 return -ENOMEM;
145 ts->pdev = pdev;
146
147 ts->fw_regs_va = dma_alloc_coherent(dev, PAGE_SIZE, &ts->fw_regs_phys,
148 GFP_KERNEL);
149 if (!ts->fw_regs_va) {
150 dev_err(dev, "failed to dma_alloc_coherent\n");
151 return -ENOMEM;
152 }
153
154 error = devm_add_action_or_reset(dev, rpi_ts_dma_cleanup, ts);
155 if (error) {
156 dev_err(dev, "failed to devm_add_action_or_reset, %d\n", error);
157 return error;
158 }
159
160 touchbuf = (u32)ts->fw_regs_phys;
161 error = rpi_firmware_property(fw, RPI_FIRMWARE_FRAMEBUFFER_SET_TOUCHBUF,
162 &touchbuf, sizeof(touchbuf));
163
164 if (error || touchbuf != 0) {
165 dev_warn(dev, "Failed to set touchbuf, %d\n", error);
166 return error;
167 }
168
169 input = devm_input_allocate_device(dev);
170 if (!input) {
171 dev_err(dev, "Failed to allocate input device\n");
172 return -ENOMEM;
173 }
174
175 ts->input = input;
176 input_set_drvdata(input, ts);
177
178 input->name = "raspberrypi-ts";
179 input->id.bustype = BUS_HOST;
180
181 input_set_abs_params(input, ABS_MT_POSITION_X, 0,
182 RPI_TS_DEFAULT_WIDTH, 0, 0);
183 input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
184 RPI_TS_DEFAULT_HEIGHT, 0, 0);
185 touchscreen_parse_properties(input, true, &ts->prop);
186
187 error = input_mt_init_slots(input, RPI_TS_MAX_SUPPORTED_POINTS,
188 INPUT_MT_DIRECT);
189 if (error) {
190 dev_err(dev, "could not init mt slots, %d\n", error);
191 return error;
192 }
193
194 error = input_setup_polling(input, rpi_ts_poll);
195 if (error) {
196 dev_err(dev, "could not set up polling mode, %d\n", error);
197 return error;
198 }
199
200 input_set_poll_interval(input, RPI_TS_POLL_INTERVAL);
201
202 error = input_register_device(input);
203 if (error) {
204 dev_err(dev, "could not register input device, %d\n", error);
205 return error;
206 }
207
208 return 0;
209}
210
211static const struct of_device_id rpi_ts_match[] = {
212 { .compatible = "raspberrypi,firmware-ts", },
213 {},
214};
215MODULE_DEVICE_TABLE(of, rpi_ts_match);
216
217static struct platform_driver rpi_ts_driver = {
218 .driver = {
219 .name = "raspberrypi-ts",
220 .of_match_table = rpi_ts_match,
221 },
222 .probe = rpi_ts_probe,
223};
224module_platform_driver(rpi_ts_driver);
225
226MODULE_AUTHOR("Gordon Hollingworth");
227MODULE_AUTHOR("Nicolas Saenz Julienne <nsaenzjulienne@suse.de>");
228MODULE_DESCRIPTION("Raspberry Pi firmware based touchscreen driver");
229MODULE_LICENSE("GPL v2");
230
