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/consumer.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 struct gpio_desc *gpiod;
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 gpiod_set_value(navpoint->gpiod, 1);
174 }
175
navpoint_down(struct navpoint * navpoint)176 static void navpoint_down(struct navpoint *navpoint)
177 {
178 struct ssp_device *ssp = navpoint->ssp;
179
180 gpiod_set_value(navpoint->gpiod, 0);
181
182 pxa_ssp_write_reg(ssp, SSCR0, 0);
183
184 clk_disable_unprepare(ssp->clk);
185 }
186
navpoint_open(struct input_dev * input)187 static int navpoint_open(struct input_dev *input)
188 {
189 struct navpoint *navpoint = input_get_drvdata(input);
190
191 navpoint_up(navpoint);
192
193 return 0;
194 }
195
navpoint_close(struct input_dev * input)196 static void navpoint_close(struct input_dev *input)
197 {
198 struct navpoint *navpoint = input_get_drvdata(input);
199
200 navpoint_down(navpoint);
201 }
202
navpoint_probe(struct platform_device * pdev)203 static int navpoint_probe(struct platform_device *pdev)
204 {
205 const struct navpoint_platform_data *pdata =
206 dev_get_platdata(&pdev->dev);
207 struct ssp_device *ssp;
208 struct input_dev *input;
209 struct navpoint *navpoint;
210 int error;
211
212 if (!pdata) {
213 dev_err(&pdev->dev, "no platform data\n");
214 return -EINVAL;
215 }
216
217 ssp = pxa_ssp_request(pdata->port, pdev->name);
218 if (!ssp)
219 return -ENODEV;
220
221 /* HaRET does not disable devices before jumping into Linux */
222 if (pxa_ssp_read_reg(ssp, SSCR0) & SSCR0_SSE) {
223 pxa_ssp_write_reg(ssp, SSCR0, 0);
224 dev_warn(&pdev->dev, "ssp%d already enabled\n", pdata->port);
225 }
226
227 navpoint = kzalloc(sizeof(*navpoint), GFP_KERNEL);
228 input = input_allocate_device();
229 if (!navpoint || !input) {
230 error = -ENOMEM;
231 goto err_free_mem;
232 }
233
234 navpoint->gpiod = gpiod_get_optional(&pdev->dev,
235 NULL, GPIOD_OUT_LOW);
236 if (IS_ERR(navpoint->gpiod)) {
237 error = PTR_ERR(navpoint->gpiod);
238 dev_err(&pdev->dev, "error getting GPIO\n");
239 goto err_free_mem;
240 }
241 gpiod_set_consumer_name(navpoint->gpiod, "SYNAPTICS_ON");
242
243 navpoint->ssp = ssp;
244 navpoint->input = input;
245 navpoint->dev = &pdev->dev;
246
247 input->name = pdev->name;
248 input->dev.parent = &pdev->dev;
249
250 __set_bit(EV_KEY, input->evbit);
251 __set_bit(EV_ABS, input->evbit);
252 __set_bit(BTN_LEFT, input->keybit);
253 __set_bit(BTN_TOUCH, input->keybit);
254 __set_bit(BTN_TOOL_FINGER, input->keybit);
255
256 input_set_abs_params(input, ABS_X,
257 NAVPOINT_X_MIN, NAVPOINT_X_MAX, 0, 0);
258 input_set_abs_params(input, ABS_Y,
259 NAVPOINT_Y_MIN, NAVPOINT_Y_MAX, 0, 0);
260 input_set_abs_params(input, ABS_PRESSURE,
261 NAVPOINT_PRESSURE_MIN, NAVPOINT_PRESSURE_MAX,
262 0, 0);
263
264 input->open = navpoint_open;
265 input->close = navpoint_close;
266
267 input_set_drvdata(input, navpoint);
268
269 error = request_irq(ssp->irq, navpoint_irq, 0, pdev->name, navpoint);
270 if (error)
271 goto err_free_mem;
272
273 error = input_register_device(input);
274 if (error)
275 goto err_free_irq;
276
277 platform_set_drvdata(pdev, navpoint);
278 dev_dbg(&pdev->dev, "ssp%d, irq %d\n", pdata->port, ssp->irq);
279
280 return 0;
281
282 err_free_irq:
283 free_irq(ssp->irq, navpoint);
284 err_free_mem:
285 input_free_device(input);
286 kfree(navpoint);
287 pxa_ssp_free(ssp);
288
289 return error;
290 }
291
navpoint_remove(struct platform_device * pdev)292 static void navpoint_remove(struct platform_device *pdev)
293 {
294 struct navpoint *navpoint = platform_get_drvdata(pdev);
295 struct ssp_device *ssp = navpoint->ssp;
296
297 free_irq(ssp->irq, navpoint);
298
299 input_unregister_device(navpoint->input);
300 kfree(navpoint);
301
302 pxa_ssp_free(ssp);
303 }
304
navpoint_suspend(struct device * dev)305 static int navpoint_suspend(struct device *dev)
306 {
307 struct platform_device *pdev = to_platform_device(dev);
308 struct navpoint *navpoint = platform_get_drvdata(pdev);
309 struct input_dev *input = navpoint->input;
310
311 mutex_lock(&input->mutex);
312 if (input_device_enabled(input))
313 navpoint_down(navpoint);
314 mutex_unlock(&input->mutex);
315
316 return 0;
317 }
318
navpoint_resume(struct device * dev)319 static int navpoint_resume(struct device *dev)
320 {
321 struct platform_device *pdev = to_platform_device(dev);
322 struct navpoint *navpoint = platform_get_drvdata(pdev);
323 struct input_dev *input = navpoint->input;
324
325 mutex_lock(&input->mutex);
326 if (input_device_enabled(input))
327 navpoint_up(navpoint);
328 mutex_unlock(&input->mutex);
329
330 return 0;
331 }
332
333 static DEFINE_SIMPLE_DEV_PM_OPS(navpoint_pm_ops,
334 navpoint_suspend, navpoint_resume);
335
336 static struct platform_driver navpoint_driver = {
337 .probe = navpoint_probe,
338 .remove_new = navpoint_remove,
339 .driver = {
340 .name = "navpoint",
341 .pm = pm_sleep_ptr(&navpoint_pm_ops),
342 },
343 };
344
345 module_platform_driver(navpoint_driver);
346
347 MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
348 MODULE_DESCRIPTION("Synaptics NavPoint (PXA27x SSP/SPI) driver");
349 MODULE_LICENSE("GPL");
350 MODULE_ALIAS("platform:navpoint");
351