1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Synaptics NavPoint (PXA27x SSP/SPI) driver.
4 *
5 * Copyright (C) 2012 Paul Parsons <lost.distance@yahoo.com>
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/clk.h>
12 #include <linux/delay.h>
13 #include <linux/gpio.h>
14 #include <linux/input.h>
15 #include <linux/input/navpoint.h>
16 #include <linux/interrupt.h>
17 #include <linux/mutex.h>
18 #include <linux/pxa2xx_ssp.h>
19 #include <linux/slab.h>
20
21 /*
22 * Synaptics Modular Embedded Protocol: Module Packet Format.
23 * Module header byte 2:0 = Length (# bytes that follow)
24 * Module header byte 4:3 = Control
25 * Module header byte 7:5 = Module Address
26 */
27 #define HEADER_LENGTH(byte) ((byte) & 0x07)
28 #define HEADER_CONTROL(byte) (((byte) >> 3) & 0x03)
29 #define HEADER_ADDRESS(byte) ((byte) >> 5)
30
31 struct navpoint {
32 struct ssp_device *ssp;
33 struct input_dev *input;
34 struct device *dev;
35 int gpio;
36 int index;
37 u8 data[1 + HEADER_LENGTH(0xff)];
38 };
39
40 /*
41 * Initialization values for SSCR0_x, SSCR1_x, SSSR_x.
42 */
43 static const u32 sscr0 = 0
44 | SSCR0_TUM /* TIM = 1; No TUR interrupts */
45 | SSCR0_RIM /* RIM = 1; No ROR interrupts */
46 | SSCR0_SSE /* SSE = 1; SSP enabled */
47 | SSCR0_Motorola /* FRF = 0; Motorola SPI */
48 | SSCR0_DataSize(16) /* DSS = 15; Data size = 16-bit */
49 ;
50 static const u32 sscr1 = 0
51 | SSCR1_SCFR /* SCFR = 1; SSPSCLK only during transfers */
52 | SSCR1_SCLKDIR /* SCLKDIR = 1; Slave mode */
53 | SSCR1_SFRMDIR /* SFRMDIR = 1; Slave mode */
54 | SSCR1_RWOT /* RWOT = 1; Receive without transmit mode */
55 | SSCR1_RxTresh(1) /* RFT = 0; Receive FIFO threshold = 1 */
56 | SSCR1_SPH /* SPH = 1; SSPSCLK inactive 0.5 + 1 cycles */
57 | SSCR1_RIE /* RIE = 1; Receive FIFO interrupt enabled */
58 ;
59 static const u32 sssr = 0
60 | SSSR_BCE /* BCE = 1; Clear BCE */
61 | SSSR_TUR /* TUR = 1; Clear TUR */
62 | SSSR_EOC /* EOC = 1; Clear EOC */
63 | SSSR_TINT /* TINT = 1; Clear TINT */
64 | SSSR_PINT /* PINT = 1; Clear PINT */
65 | SSSR_ROR /* ROR = 1; Clear ROR */
66 ;
67
68 /*
69 * MEP Query $22: Touchpad Coordinate Range Query is not supported by
70 * the NavPoint module, so sampled values provide the default limits.
71 */
72 #define NAVPOINT_X_MIN 1278
73 #define NAVPOINT_X_MAX 5340
74 #define NAVPOINT_Y_MIN 1572
75 #define NAVPOINT_Y_MAX 4396
76 #define NAVPOINT_PRESSURE_MIN 0
77 #define NAVPOINT_PRESSURE_MAX 255
78
navpoint_packet(struct navpoint * navpoint)79 static void navpoint_packet(struct navpoint *navpoint)
80 {
81 int finger;
82 int gesture;
83 int x, y, z;
84
85 switch (navpoint->data[0]) {
86 case 0xff: /* Garbage (packet?) between reset and Hello packet */
87 case 0x00: /* Module 0, NULL packet */
88 break;
89
90 case 0x0e: /* Module 0, Absolute packet */
91 finger = (navpoint->data[1] & 0x01);
92 gesture = (navpoint->data[1] & 0x02);
93 x = ((navpoint->data[2] & 0x1f) << 8) | navpoint->data[3];
94 y = ((navpoint->data[4] & 0x1f) << 8) | navpoint->data[5];
95 z = navpoint->data[6];
96 input_report_key(navpoint->input, BTN_TOUCH, finger);
97 input_report_abs(navpoint->input, ABS_X, x);
98 input_report_abs(navpoint->input, ABS_Y, y);
99 input_report_abs(navpoint->input, ABS_PRESSURE, z);
100 input_report_key(navpoint->input, BTN_TOOL_FINGER, finger);
101 input_report_key(navpoint->input, BTN_LEFT, gesture);
102 input_sync(navpoint->input);
103 break;
104
105 case 0x19: /* Module 0, Hello packet */
106 if ((navpoint->data[1] & 0xf0) == 0x10)
107 break;
108 fallthrough;
109 default:
110 dev_warn(navpoint->dev,
111 "spurious packet: data=0x%02x,0x%02x,...\n",
112 navpoint->data[0], navpoint->data[1]);
113 break;
114 }
115 }
116
navpoint_irq(int irq,void * dev_id)117 static irqreturn_t navpoint_irq(int irq, void *dev_id)
118 {
119 struct navpoint *navpoint = dev_id;
120 struct ssp_device *ssp = navpoint->ssp;
121 irqreturn_t ret = IRQ_NONE;
122 u32 status;
123
124 status = pxa_ssp_read_reg(ssp, SSSR);
125 if (status & sssr) {
126 dev_warn(navpoint->dev,
127 "unexpected interrupt: status=0x%08x\n", status);
128 pxa_ssp_write_reg(ssp, SSSR, (status & sssr));
129 ret = IRQ_HANDLED;
130 }
131
132 while (status & SSSR_RNE) {
133 u32 data;
134
135 data = pxa_ssp_read_reg(ssp, SSDR);
136 navpoint->data[navpoint->index + 0] = (data >> 8);
137 navpoint->data[navpoint->index + 1] = data;
138 navpoint->index += 2;
139 if (HEADER_LENGTH(navpoint->data[0]) < navpoint->index) {
140 navpoint_packet(navpoint);
141 navpoint->index = 0;
142 }
143 status = pxa_ssp_read_reg(ssp, SSSR);
144 ret = IRQ_HANDLED;
145 }
146
147 return ret;
148 }
149
navpoint_up(struct navpoint * navpoint)150 static void navpoint_up(struct navpoint *navpoint)
151 {
152 struct ssp_device *ssp = navpoint->ssp;
153 int timeout;
154
155 clk_prepare_enable(ssp->clk);
156
157 pxa_ssp_write_reg(ssp, SSCR1, sscr1);
158 pxa_ssp_write_reg(ssp, SSSR, sssr);
159 pxa_ssp_write_reg(ssp, SSTO, 0);
160 pxa_ssp_write_reg(ssp, SSCR0, sscr0); /* SSCR0_SSE written last */
161
162 /* Wait until SSP port is ready for slave clock operations */
163 for (timeout = 100; timeout != 0; --timeout) {
164 if (!(pxa_ssp_read_reg(ssp, SSSR) & SSSR_CSS))
165 break;
166 msleep(1);
167 }
168
169 if (timeout == 0)
170 dev_err(navpoint->dev,
171 "timeout waiting for SSSR[CSS] to clear\n");
172
173 if (gpio_is_valid(navpoint->gpio))
174 gpio_set_value(navpoint->gpio, 1);
175 }
176
navpoint_down(struct navpoint * navpoint)177 static void navpoint_down(struct navpoint *navpoint)
178 {
179 struct ssp_device *ssp = navpoint->ssp;
180
181 if (gpio_is_valid(navpoint->gpio))
182 gpio_set_value(navpoint->gpio, 0);
183
184 pxa_ssp_write_reg(ssp, SSCR0, 0);
185
186 clk_disable_unprepare(ssp->clk);
187 }
188
navpoint_open(struct input_dev * input)189 static int navpoint_open(struct input_dev *input)
190 {
191 struct navpoint *navpoint = input_get_drvdata(input);
192
193 navpoint_up(navpoint);
194
195 return 0;
196 }
197
navpoint_close(struct input_dev * input)198 static void navpoint_close(struct input_dev *input)
199 {
200 struct navpoint *navpoint = input_get_drvdata(input);
201
202 navpoint_down(navpoint);
203 }
204
navpoint_probe(struct platform_device * pdev)205 static int navpoint_probe(struct platform_device *pdev)
206 {
207 const struct navpoint_platform_data *pdata =
208 dev_get_platdata(&pdev->dev);
209 struct ssp_device *ssp;
210 struct input_dev *input;
211 struct navpoint *navpoint;
212 int error;
213
214 if (!pdata) {
215 dev_err(&pdev->dev, "no platform data\n");
216 return -EINVAL;
217 }
218
219 if (gpio_is_valid(pdata->gpio)) {
220 error = gpio_request_one(pdata->gpio, GPIOF_OUT_INIT_LOW,
221 "SYNAPTICS_ON");
222 if (error)
223 return error;
224 }
225
226 ssp = pxa_ssp_request(pdata->port, pdev->name);
227 if (!ssp) {
228 error = -ENODEV;
229 goto err_free_gpio;
230 }
231
232 /* HaRET does not disable devices before jumping into Linux */
233 if (pxa_ssp_read_reg(ssp, SSCR0) & SSCR0_SSE) {
234 pxa_ssp_write_reg(ssp, SSCR0, 0);
235 dev_warn(&pdev->dev, "ssp%d already enabled\n", pdata->port);
236 }
237
238 navpoint = kzalloc(sizeof(*navpoint), GFP_KERNEL);
239 input = input_allocate_device();
240 if (!navpoint || !input) {
241 error = -ENOMEM;
242 goto err_free_mem;
243 }
244
245 navpoint->ssp = ssp;
246 navpoint->input = input;
247 navpoint->dev = &pdev->dev;
248 navpoint->gpio = pdata->gpio;
249
250 input->name = pdev->name;
251 input->dev.parent = &pdev->dev;
252
253 __set_bit(EV_KEY, input->evbit);
254 __set_bit(EV_ABS, input->evbit);
255 __set_bit(BTN_LEFT, input->keybit);
256 __set_bit(BTN_TOUCH, input->keybit);
257 __set_bit(BTN_TOOL_FINGER, input->keybit);
258
259 input_set_abs_params(input, ABS_X,
260 NAVPOINT_X_MIN, NAVPOINT_X_MAX, 0, 0);
261 input_set_abs_params(input, ABS_Y,
262 NAVPOINT_Y_MIN, NAVPOINT_Y_MAX, 0, 0);
263 input_set_abs_params(input, ABS_PRESSURE,
264 NAVPOINT_PRESSURE_MIN, NAVPOINT_PRESSURE_MAX,
265 0, 0);
266
267 input->open = navpoint_open;
268 input->close = navpoint_close;
269
270 input_set_drvdata(input, navpoint);
271
272 error = request_irq(ssp->irq, navpoint_irq, 0, pdev->name, navpoint);
273 if (error)
274 goto err_free_mem;
275
276 error = input_register_device(input);
277 if (error)
278 goto err_free_irq;
279
280 platform_set_drvdata(pdev, navpoint);
281 dev_dbg(&pdev->dev, "ssp%d, irq %d\n", pdata->port, ssp->irq);
282
283 return 0;
284
285 err_free_irq:
286 free_irq(ssp->irq, navpoint);
287 err_free_mem:
288 input_free_device(input);
289 kfree(navpoint);
290 pxa_ssp_free(ssp);
291 err_free_gpio:
292 if (gpio_is_valid(pdata->gpio))
293 gpio_free(pdata->gpio);
294
295 return error;
296 }
297
navpoint_remove(struct platform_device * pdev)298 static int navpoint_remove(struct platform_device *pdev)
299 {
300 const struct navpoint_platform_data *pdata =
301 dev_get_platdata(&pdev->dev);
302 struct navpoint *navpoint = platform_get_drvdata(pdev);
303 struct ssp_device *ssp = navpoint->ssp;
304
305 free_irq(ssp->irq, navpoint);
306
307 input_unregister_device(navpoint->input);
308 kfree(navpoint);
309
310 pxa_ssp_free(ssp);
311
312 if (gpio_is_valid(pdata->gpio))
313 gpio_free(pdata->gpio);
314
315 return 0;
316 }
317
navpoint_suspend(struct device * dev)318 static int navpoint_suspend(struct device *dev)
319 {
320 struct platform_device *pdev = to_platform_device(dev);
321 struct navpoint *navpoint = platform_get_drvdata(pdev);
322 struct input_dev *input = navpoint->input;
323
324 mutex_lock(&input->mutex);
325 if (input_device_enabled(input))
326 navpoint_down(navpoint);
327 mutex_unlock(&input->mutex);
328
329 return 0;
330 }
331
navpoint_resume(struct device * dev)332 static int navpoint_resume(struct device *dev)
333 {
334 struct platform_device *pdev = to_platform_device(dev);
335 struct navpoint *navpoint = platform_get_drvdata(pdev);
336 struct input_dev *input = navpoint->input;
337
338 mutex_lock(&input->mutex);
339 if (input_device_enabled(input))
340 navpoint_up(navpoint);
341 mutex_unlock(&input->mutex);
342
343 return 0;
344 }
345
346 static DEFINE_SIMPLE_DEV_PM_OPS(navpoint_pm_ops,
347 navpoint_suspend, navpoint_resume);
348
349 static struct platform_driver navpoint_driver = {
350 .probe = navpoint_probe,
351 .remove = navpoint_remove,
352 .driver = {
353 .name = "navpoint",
354 .pm = pm_sleep_ptr(&navpoint_pm_ops),
355 },
356 };
357
358 module_platform_driver(navpoint_driver);
359
360 MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
361 MODULE_DESCRIPTION("Synaptics NavPoint (PXA27x SSP/SPI) driver");
362 MODULE_LICENSE("GPL");
363 MODULE_ALIAS("platform:navpoint");
364