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