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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Allwinner sunxi resistive touchscreen controller driver
4 *
5 * Copyright (C) 2013 - 2014 Hans de Goede <[email protected]>
6 *
7 * The hwmon parts are based on work by Corentin LABBE which is:
8 * Copyright (C) 2013 Corentin LABBE <[email protected]>
9 */
10
11/*
12 * The sun4i-ts controller is capable of detecting a second touch, but when a
13 * second touch is present then the accuracy becomes so bad the reported touch
14 * location is not useable.
15 *
16 * The original android driver contains some complicated heuristics using the
17 * aprox. distance between the 2 touches to see if the user is making a pinch
18 * open / close movement, and then reports emulated multi-touch events around
19 * the last touch coordinate (as the dual-touch coordinates are worthless).
20 *
21 * These kinds of heuristics are just asking for trouble (and don't belong
22 * in the kernel). So this driver offers straight forward, reliable single
23 * touch functionality only.
24 *
25 * s.a. A20 User Manual "1.15 TP" (Documentation/arch/arm/sunxi.rst)
26 * (looks like the description in the A20 User Manual v1.3 is better
27 * than the one in the A10 User Manual v.1.5)
28 */
29
30#include <linux/err.h>
31#include <linux/hwmon.h>
32#include <linux/thermal.h>
33#include <linux/init.h>
34#include <linux/input.h>
35#include <linux/interrupt.h>
36#include <linux/io.h>
37#include <linux/module.h>
38#include <linux/of_platform.h>
39#include <linux/platform_device.h>
40#include <linux/slab.h>
41
42#define TP_CTRL0 0x00
43#define TP_CTRL1 0x04
44#define TP_CTRL2 0x08
45#define TP_CTRL3 0x0c
46#define TP_INT_FIFOC 0x10
47#define TP_INT_FIFOS 0x14
48#define TP_TPR 0x18
49#define TP_CDAT 0x1c
50#define TEMP_DATA 0x20
51#define TP_DATA 0x24
52
53/* TP_CTRL0 bits */
54#define ADC_FIRST_DLY(x) ((x) << 24) /* 8 bits */
55#define ADC_FIRST_DLY_MODE(x) ((x) << 23)
56#define ADC_CLK_SEL(x) ((x) << 22)
57#define ADC_CLK_DIV(x) ((x) << 20) /* 3 bits */
58#define FS_DIV(x) ((x) << 16) /* 4 bits */
59#define T_ACQ(x) ((x) << 0) /* 16 bits */
60
61/* TP_CTRL1 bits */
62#define STYLUS_UP_DEBOUN(x) ((x) << 12) /* 8 bits */
63#define STYLUS_UP_DEBOUN_EN(x) ((x) << 9)
64#define TOUCH_PAN_CALI_EN(x) ((x) << 6)
65#define TP_DUAL_EN(x) ((x) << 5)
66#define TP_MODE_EN(x) ((x) << 4)
67#define TP_ADC_SELECT(x) ((x) << 3)
68#define ADC_CHAN_SELECT(x) ((x) << 0) /* 3 bits */
69
70/* on sun6i, bits 3~6 are left shifted by 1 to 4~7 */
71#define SUN6I_TP_MODE_EN(x) ((x) << 5)
72
73/* TP_CTRL2 bits */
74#define TP_SENSITIVE_ADJUST(x) ((x) << 28) /* 4 bits */
75#define TP_MODE_SELECT(x) ((x) << 26) /* 2 bits */
76#define PRE_MEA_EN(x) ((x) << 24)
77#define PRE_MEA_THRE_CNT(x) ((x) << 0) /* 24 bits */
78
79/* TP_CTRL3 bits */
80#define FILTER_EN(x) ((x) << 2)
81#define FILTER_TYPE(x) ((x) << 0) /* 2 bits */
82
83/* TP_INT_FIFOC irq and fifo mask / control bits */
84#define TEMP_IRQ_EN(x) ((x) << 18)
85#define OVERRUN_IRQ_EN(x) ((x) << 17)
86#define DATA_IRQ_EN(x) ((x) << 16)
87#define TP_DATA_XY_CHANGE(x) ((x) << 13)
88#define FIFO_TRIG(x) ((x) << 8) /* 5 bits */
89#define DATA_DRQ_EN(x) ((x) << 7)
90#define FIFO_FLUSH(x) ((x) << 4)
91#define TP_UP_IRQ_EN(x) ((x) << 1)
92#define TP_DOWN_IRQ_EN(x) ((x) << 0)
93
94/* TP_INT_FIFOS irq and fifo status bits */
95#define TEMP_DATA_PENDING BIT(18)
96#define FIFO_OVERRUN_PENDING BIT(17)
97#define FIFO_DATA_PENDING BIT(16)
98#define TP_IDLE_FLG BIT(2)
99#define TP_UP_PENDING BIT(1)
100#define TP_DOWN_PENDING BIT(0)
101
102/* TP_TPR bits */
103#define TEMP_ENABLE(x) ((x) << 16)
104#define TEMP_PERIOD(x) ((x) << 0) /* t = x * 256 * 16 / clkin */
105
106struct sun4i_ts_data {
107 struct device *dev;
108 struct input_dev *input;
109 void __iomem *base;
110 unsigned int irq;
111 bool ignore_fifo_data;
112 int temp_data;
113 int temp_offset;
114 int temp_step;
115};
116
117static void sun4i_ts_irq_handle_input(struct sun4i_ts_data *ts, u32 reg_val)
118{
119 u32 x, y;
120
121 if (reg_val & FIFO_DATA_PENDING) {
122 x = readl(ts->base + TP_DATA);
123 y = readl(ts->base + TP_DATA);
124 /* The 1st location reported after an up event is unreliable */
125 if (!ts->ignore_fifo_data) {
126 input_report_abs(ts->input, ABS_X, x);
127 input_report_abs(ts->input, ABS_Y, y);
128 /*
129 * The hardware has a separate down status bit, but
130 * that gets set before we get the first location,
131 * resulting in reporting a click on the old location.
132 */
133 input_report_key(ts->input, BTN_TOUCH, 1);
134 input_sync(ts->input);
135 } else {
136 ts->ignore_fifo_data = false;
137 }
138 }
139
140 if (reg_val & TP_UP_PENDING) {
141 ts->ignore_fifo_data = true;
142 input_report_key(ts->input, BTN_TOUCH, 0);
143 input_sync(ts->input);
144 }
145}
146
147static irqreturn_t sun4i_ts_irq(int irq, void *dev_id)
148{
149 struct sun4i_ts_data *ts = dev_id;
150 u32 reg_val;
151
152 reg_val = readl(ts->base + TP_INT_FIFOS);
153
154 if (reg_val & TEMP_DATA_PENDING)
155 ts->temp_data = readl(ts->base + TEMP_DATA);
156
157 if (ts->input)
158 sun4i_ts_irq_handle_input(ts, reg_val);
159
160 writel(reg_val, ts->base + TP_INT_FIFOS);
161
162 return IRQ_HANDLED;
163}
164
165static int sun4i_ts_open(struct input_dev *dev)
166{
167 struct sun4i_ts_data *ts = input_get_drvdata(dev);
168
169 /* Flush, set trig level to 1, enable temp, data and up irqs */
170 writel(TEMP_IRQ_EN(1) | DATA_IRQ_EN(1) | FIFO_TRIG(1) | FIFO_FLUSH(1) |
171 TP_UP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
172
173 return 0;
174}
175
176static void sun4i_ts_close(struct input_dev *dev)
177{
178 struct sun4i_ts_data *ts = input_get_drvdata(dev);
179
180 /* Deactivate all input IRQs */
181 writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
182}
183
184static int sun4i_get_temp(const struct sun4i_ts_data *ts, int *temp)
185{
186 /* No temp_data until the first irq */
187 if (ts->temp_data == -1)
188 return -EAGAIN;
189
190 *temp = ts->temp_data * ts->temp_step - ts->temp_offset;
191
192 return 0;
193}
194
195static int sun4i_get_tz_temp(struct thermal_zone_device *tz, int *temp)
196{
197 return sun4i_get_temp(thermal_zone_device_priv(tz), temp);
198}
199
200static const struct thermal_zone_device_ops sun4i_ts_tz_ops = {
201 .get_temp = sun4i_get_tz_temp,
202};
203
204static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
205 char *buf)
206{
207 struct sun4i_ts_data *ts = dev_get_drvdata(dev);
208 int temp;
209 int error;
210
211 error = sun4i_get_temp(ts, &temp);
212 if (error)
213 return error;
214
215 return sprintf(buf, "%d\n", temp);
216}
217
218static ssize_t show_temp_label(struct device *dev,
219 struct device_attribute *devattr, char *buf)
220{
221 return sprintf(buf, "SoC temperature\n");
222}
223
224static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL);
225static DEVICE_ATTR(temp1_label, S_IRUGO, show_temp_label, NULL);
226
227static struct attribute *sun4i_ts_attrs[] = {
228 &dev_attr_temp1_input.attr,
229 &dev_attr_temp1_label.attr,
230 NULL
231};
232ATTRIBUTE_GROUPS(sun4i_ts);
233
234static int sun4i_ts_probe(struct platform_device *pdev)
235{
236 struct sun4i_ts_data *ts;
237 struct device *dev = &pdev->dev;
238 struct device_node *np = dev->of_node;
239 struct device *hwmon;
240 struct thermal_zone_device *thermal;
241 int error;
242 u32 reg;
243 bool ts_attached;
244 u32 tp_sensitive_adjust = 15;
245 u32 filter_type = 1;
246
247 ts = devm_kzalloc(dev, sizeof(struct sun4i_ts_data), GFP_KERNEL);
248 if (!ts)
249 return -ENOMEM;
250
251 ts->dev = dev;
252 ts->ignore_fifo_data = true;
253 ts->temp_data = -1;
254 if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts")) {
255 /* Allwinner SDK has temperature (C) = (value / 6) - 271 */
256 ts->temp_offset = 271000;
257 ts->temp_step = 167;
258 } else if (of_device_is_compatible(np, "allwinner,sun4i-a10-ts")) {
259 /*
260 * The A10 temperature sensor has quite a wide spread, these
261 * parameters are based on the averaging of the calibration
262 * results of 4 completely different boards, with a spread of
263 * temp_step from 0.096 - 0.170 and temp_offset from 176 - 331.
264 */
265 ts->temp_offset = 257000;
266 ts->temp_step = 133;
267 } else {
268 /*
269 * The user manuals do not contain the formula for calculating
270 * the temperature. The formula used here is from the AXP209,
271 * which is designed by X-Powers, an affiliate of Allwinner:
272 *
273 * temperature (C) = (value * 0.1) - 144.7
274 *
275 * Allwinner does not have any documentation whatsoever for
276 * this hardware. Moreover, it is claimed that the sensor
277 * is inaccurate and cannot work properly.
278 */
279 ts->temp_offset = 144700;
280 ts->temp_step = 100;
281 }
282
283 ts_attached = of_property_read_bool(np, "allwinner,ts-attached");
284 if (ts_attached) {
285 ts->input = devm_input_allocate_device(dev);
286 if (!ts->input)
287 return -ENOMEM;
288
289 ts->input->name = pdev->name;
290 ts->input->phys = "sun4i_ts/input0";
291 ts->input->open = sun4i_ts_open;
292 ts->input->close = sun4i_ts_close;
293 ts->input->id.bustype = BUS_HOST;
294 ts->input->id.vendor = 0x0001;
295 ts->input->id.product = 0x0001;
296 ts->input->id.version = 0x0100;
297 ts->input->evbit[0] = BIT(EV_SYN) | BIT(EV_KEY) | BIT(EV_ABS);
298 __set_bit(BTN_TOUCH, ts->input->keybit);
299 input_set_abs_params(ts->input, ABS_X, 0, 4095, 0, 0);
300 input_set_abs_params(ts->input, ABS_Y, 0, 4095, 0, 0);
301 input_set_drvdata(ts->input, ts);
302 }
303
304 ts->base = devm_platform_ioremap_resource(pdev, 0);
305 if (IS_ERR(ts->base))
306 return PTR_ERR(ts->base);
307
308 ts->irq = platform_get_irq(pdev, 0);
309 error = devm_request_irq(dev, ts->irq, sun4i_ts_irq, 0, "sun4i-ts", ts);
310 if (error)
311 return error;
312
313 /*
314 * Select HOSC clk, clkin = clk / 6, adc samplefreq = clkin / 8192,
315 * t_acq = clkin / (16 * 64)
316 */
317 writel(ADC_CLK_SEL(0) | ADC_CLK_DIV(2) | FS_DIV(7) | T_ACQ(63),
318 ts->base + TP_CTRL0);
319
320 /*
321 * tp_sensitive_adjust is an optional property
322 * tp_mode = 0 : only x and y coordinates, as we don't use dual touch
323 */
324 of_property_read_u32(np, "allwinner,tp-sensitive-adjust",
325 &tp_sensitive_adjust);
326 writel(TP_SENSITIVE_ADJUST(tp_sensitive_adjust) | TP_MODE_SELECT(0),
327 ts->base + TP_CTRL2);
328
329 /*
330 * Enable median and averaging filter, optional property for
331 * filter type.
332 */
333 of_property_read_u32(np, "allwinner,filter-type", &filter_type);
334 writel(FILTER_EN(1) | FILTER_TYPE(filter_type), ts->base + TP_CTRL3);
335
336 /* Enable temperature measurement, period 1953 (2 seconds) */
337 writel(TEMP_ENABLE(1) | TEMP_PERIOD(1953), ts->base + TP_TPR);
338
339 /*
340 * Set stylus up debounce to aprox 10 ms, enable debounce, and
341 * finally enable tp mode.
342 */
343 reg = STYLUS_UP_DEBOUN(5) | STYLUS_UP_DEBOUN_EN(1);
344 if (of_device_is_compatible(np, "allwinner,sun6i-a31-ts"))
345 reg |= SUN6I_TP_MODE_EN(1);
346 else
347 reg |= TP_MODE_EN(1);
348 writel(reg, ts->base + TP_CTRL1);
349
350 /*
351 * The thermal core does not register hwmon devices for DT-based
352 * thermal zone sensors, such as this one.
353 */
354 hwmon = devm_hwmon_device_register_with_groups(ts->dev, "sun4i_ts",
355 ts, sun4i_ts_groups);
356 if (IS_ERR(hwmon))
357 return PTR_ERR(hwmon);
358
359 thermal = devm_thermal_of_zone_register(ts->dev, 0, ts,
360 &sun4i_ts_tz_ops);
361 if (IS_ERR(thermal))
362 return PTR_ERR(thermal);
363
364 writel(TEMP_IRQ_EN(1), ts->base + TP_INT_FIFOC);
365
366 if (ts_attached) {
367 error = input_register_device(ts->input);
368 if (error) {
369 writel(0, ts->base + TP_INT_FIFOC);
370 return error;
371 }
372 }
373
374 platform_set_drvdata(pdev, ts);
375 return 0;
376}
377
378static void sun4i_ts_remove(struct platform_device *pdev)
379{
380 struct sun4i_ts_data *ts = platform_get_drvdata(pdev);
381
382 /* Explicit unregister to avoid open/close changing the imask later */
383 if (ts->input)
384 input_unregister_device(ts->input);
385
386 /* Deactivate all IRQs */
387 writel(0, ts->base + TP_INT_FIFOC);
388}
389
390static const struct of_device_id sun4i_ts_of_match[] = {
391 { .compatible = "allwinner,sun4i-a10-ts", },
392 { .compatible = "allwinner,sun5i-a13-ts", },
393 { .compatible = "allwinner,sun6i-a31-ts", },
394 { /* sentinel */ }
395};
396MODULE_DEVICE_TABLE(of, sun4i_ts_of_match);
397
398static struct platform_driver sun4i_ts_driver = {
399 .driver = {
400 .name = "sun4i-ts",
401 .of_match_table = sun4i_ts_of_match,
402 },
403 .probe = sun4i_ts_probe,
404 .remove = sun4i_ts_remove,
405};
406
407module_platform_driver(sun4i_ts_driver);
408
409MODULE_DESCRIPTION("Allwinner sun4i resistive touchscreen controller driver");
410MODULE_AUTHOR("Hans de Goede <[email protected]>");
411MODULE_LICENSE("GPL");