1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * LoCoMo keyboard driver for Linux-based ARM PDAs:
4  * 	- SHARP Zaurus Collie (SL-5500)
5  * 	- SHARP Zaurus Poodle (SL-5600)
6  *
7  * Copyright (c) 2005 John Lenz
8  * Based on from xtkbd.c
9  */
10 
11 #include <linux/slab.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/input.h>
15 #include <linux/delay.h>
16 #include <linux/device.h>
17 #include <linux/interrupt.h>
18 #include <linux/ioport.h>
19 
20 #include <asm/hardware/locomo.h>
21 #include <asm/irq.h>
22 
23 MODULE_AUTHOR("John Lenz <lenz@cs.wisc.edu>");
24 MODULE_DESCRIPTION("LoCoMo keyboard driver");
25 MODULE_LICENSE("GPL");
26 
27 #define LOCOMOKBD_NUMKEYS	128
28 
29 #define KEY_ACTIVITY		KEY_F16
30 #define KEY_CONTACT		KEY_F18
31 #define KEY_CENTER		KEY_F15
32 
33 static const unsigned char
34 locomokbd_keycode[LOCOMOKBD_NUMKEYS] = {
35 	0, KEY_ESC, KEY_ACTIVITY, 0, 0, 0, 0, 0, 0, 0,				/* 0 - 9 */
36 	0, 0, 0, 0, 0, 0, 0, KEY_MENU, KEY_HOME, KEY_CONTACT,			/* 10 - 19 */
37 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0,						/* 20 - 29 */
38 	0, 0, 0, KEY_CENTER, 0, KEY_MAIL, 0, 0, 0, 0,				/* 30 - 39 */
39 	0, 0, 0, 0, 0, 0, 0, 0, 0, KEY_RIGHT,					/* 40 - 49 */
40 	KEY_UP, KEY_LEFT, 0, 0, KEY_P, 0, KEY_O, KEY_I, KEY_Y, KEY_T,		/* 50 - 59 */
41 	KEY_E, KEY_W, 0, 0, 0, 0, KEY_DOWN, KEY_ENTER, 0, 0,			/* 60 - 69 */
42 	KEY_BACKSPACE, 0, KEY_L, KEY_U, KEY_H, KEY_R, KEY_D, KEY_Q, 0, 0,	/* 70 - 79 */
43 	0, 0, 0, 0, 0, 0, KEY_ENTER, KEY_RIGHTSHIFT, KEY_K, KEY_J,		/* 80 - 89 */
44 	KEY_G, KEY_F, KEY_X, KEY_S, 0, 0, 0, 0, 0, 0,				/* 90 - 99 */
45 	0, 0, KEY_DOT, 0, KEY_COMMA, KEY_N, KEY_B, KEY_C, KEY_Z, KEY_A,		/* 100 - 109 */
46 	KEY_LEFTSHIFT, KEY_TAB, KEY_LEFTCTRL, 0, 0, 0, 0, 0, 0, 0,		/* 110 - 119 */
47 	KEY_M, KEY_SPACE, KEY_V, KEY_APOSTROPHE, KEY_SLASH, 0, 0, 0		/* 120 - 128 */
48 };
49 
50 #define KB_ROWS			16
51 #define KB_COLS			8
52 #define KB_ROWMASK(r)		(1 << (r))
53 #define SCANCODE(c,r)		( ((c)<<4) + (r) + 1 )
54 
55 #define KB_DELAY		8
56 #define SCAN_INTERVAL		(HZ/10)
57 
58 struct locomokbd {
59 	unsigned char keycode[LOCOMOKBD_NUMKEYS];
60 	struct input_dev *input;
61 	char phys[32];
62 
63 	unsigned long base;
64 	spinlock_t lock;
65 
66 	struct timer_list timer;
67 	unsigned long suspend_jiffies;
68 	unsigned int count_cancel;
69 };
70 
71 /* helper functions for reading the keyboard matrix */
72 static inline void locomokbd_charge_all(unsigned long membase)
73 {
74 	locomo_writel(0x00FF, membase + LOCOMO_KSC);
75 }
76 
77 static inline void locomokbd_activate_all(unsigned long membase)
78 {
79 	unsigned long r;
80 
81 	locomo_writel(0, membase + LOCOMO_KSC);
82 	r = locomo_readl(membase + LOCOMO_KIC);
83 	r &= 0xFEFF;
84 	locomo_writel(r, membase + LOCOMO_KIC);
85 }
86 
87 static inline void locomokbd_activate_col(unsigned long membase, int col)
88 {
89 	unsigned short nset;
90 	unsigned short nbset;
91 
92 	nset = 0xFF & ~(1 << col);
93 	nbset = (nset << 8) + nset;
94 	locomo_writel(nbset, membase + LOCOMO_KSC);
95 }
96 
97 static inline void locomokbd_reset_col(unsigned long membase, int col)
98 {
99 	unsigned short nbset;
100 
101 	nbset = ((0xFF & ~(1 << col)) << 8) + 0xFF;
102 	locomo_writel(nbset, membase + LOCOMO_KSC);
103 }
104 
105 /*
106  * The LoCoMo keyboard only generates interrupts when a key is pressed.
107  * So when a key is pressed, we enable a timer.  This timer scans the
108  * keyboard, and this is how we detect when the key is released.
109  */
110 
111 /* Scan the hardware keyboard and push any changes up through the input layer */
112 static void locomokbd_scankeyboard(struct locomokbd *locomokbd)
113 {
114 	unsigned int row, col, rowd;
115 	unsigned long flags;
116 	unsigned int num_pressed;
117 	unsigned long membase = locomokbd->base;
118 
119 	spin_lock_irqsave(&locomokbd->lock, flags);
120 
121 	locomokbd_charge_all(membase);
122 
123 	num_pressed = 0;
124 	for (col = 0; col < KB_COLS; col++) {
125 
126 		locomokbd_activate_col(membase, col);
127 		udelay(KB_DELAY);
128 
129 		rowd = ~locomo_readl(membase + LOCOMO_KIB);
130 		for (row = 0; row < KB_ROWS; row++) {
131 			unsigned int scancode, pressed, key;
132 
133 			scancode = SCANCODE(col, row);
134 			pressed = rowd & KB_ROWMASK(row);
135 			key = locomokbd->keycode[scancode];
136 
137 			input_report_key(locomokbd->input, key, pressed);
138 			if (likely(!pressed))
139 				continue;
140 
141 			num_pressed++;
142 
143 			/* The "Cancel/ESC" key is labeled "On/Off" on
144 			 * Collie and Poodle and should suspend the device
145 			 * if it was pressed for more than a second. */
146 			if (unlikely(key == KEY_ESC)) {
147 				if (!time_after(jiffies,
148 					locomokbd->suspend_jiffies + HZ))
149 					continue;
150 				if (locomokbd->count_cancel++
151 					!= (HZ/SCAN_INTERVAL + 1))
152 					continue;
153 				input_event(locomokbd->input, EV_PWR,
154 					KEY_SUSPEND, 1);
155 				locomokbd->suspend_jiffies = jiffies;
156 			} else
157 				locomokbd->count_cancel = 0;
158 		}
159 		locomokbd_reset_col(membase, col);
160 	}
161 	locomokbd_activate_all(membase);
162 
163 	input_sync(locomokbd->input);
164 
165 	/* if any keys are pressed, enable the timer */
166 	if (num_pressed)
167 		mod_timer(&locomokbd->timer, jiffies + SCAN_INTERVAL);
168 	else
169 		locomokbd->count_cancel = 0;
170 
171 	spin_unlock_irqrestore(&locomokbd->lock, flags);
172 }
173 
174 /*
175  * LoCoMo keyboard interrupt handler.
176  */
177 static irqreturn_t locomokbd_interrupt(int irq, void *dev_id)
178 {
179 	struct locomokbd *locomokbd = dev_id;
180 	u16 r;
181 
182 	r = locomo_readl(locomokbd->base + LOCOMO_KIC);
183 	if ((r & 0x0001) == 0)
184 		return IRQ_HANDLED;
185 
186 	locomo_writel(r & ~0x0100, locomokbd->base + LOCOMO_KIC); /* Ack */
187 
188 	/** wait chattering delay **/
189 	udelay(100);
190 
191 	locomokbd_scankeyboard(locomokbd);
192 	return IRQ_HANDLED;
193 }
194 
195 /*
196  * LoCoMo timer checking for released keys
197  */
198 static void locomokbd_timer_callback(struct timer_list *t)
199 {
200 	struct locomokbd *locomokbd = from_timer(locomokbd, t, timer);
201 
202 	locomokbd_scankeyboard(locomokbd);
203 }
204 
205 static int locomokbd_open(struct input_dev *dev)
206 {
207 	struct locomokbd *locomokbd = input_get_drvdata(dev);
208 	u16 r;
209 
210 	r = locomo_readl(locomokbd->base + LOCOMO_KIC) | 0x0010;
211 	locomo_writel(r, locomokbd->base + LOCOMO_KIC);
212 	return 0;
213 }
214 
215 static void locomokbd_close(struct input_dev *dev)
216 {
217 	struct locomokbd *locomokbd = input_get_drvdata(dev);
218 	u16 r;
219 
220 	r = locomo_readl(locomokbd->base + LOCOMO_KIC) & ~0x0010;
221 	locomo_writel(r, locomokbd->base + LOCOMO_KIC);
222 }
223 
224 static int locomokbd_probe(struct locomo_dev *dev)
225 {
226 	struct locomokbd *locomokbd;
227 	struct input_dev *input_dev;
228 	int i, err;
229 
230 	locomokbd = kzalloc(sizeof(struct locomokbd), GFP_KERNEL);
231 	input_dev = input_allocate_device();
232 	if (!locomokbd || !input_dev) {
233 		err = -ENOMEM;
234 		goto err_free_mem;
235 	}
236 
237 	/* try and claim memory region */
238 	if (!request_mem_region((unsigned long) dev->mapbase,
239 				dev->length,
240 				LOCOMO_DRIVER_NAME(dev))) {
241 		err = -EBUSY;
242 		printk(KERN_ERR "locomokbd: Can't acquire access to io memory for keyboard\n");
243 		goto err_free_mem;
244 	}
245 
246 	locomo_set_drvdata(dev, locomokbd);
247 
248 	locomokbd->base = (unsigned long) dev->mapbase;
249 
250 	spin_lock_init(&locomokbd->lock);
251 
252 	timer_setup(&locomokbd->timer, locomokbd_timer_callback, 0);
253 
254 	locomokbd->suspend_jiffies = jiffies;
255 
256 	locomokbd->input = input_dev;
257 	strcpy(locomokbd->phys, "locomokbd/input0");
258 
259 	input_dev->name = "LoCoMo keyboard";
260 	input_dev->phys = locomokbd->phys;
261 	input_dev->id.bustype = BUS_HOST;
262 	input_dev->id.vendor = 0x0001;
263 	input_dev->id.product = 0x0001;
264 	input_dev->id.version = 0x0100;
265 	input_dev->open = locomokbd_open;
266 	input_dev->close = locomokbd_close;
267 	input_dev->dev.parent = &dev->dev;
268 
269 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_REP) |
270 				BIT_MASK(EV_PWR);
271 	input_dev->keycode = locomokbd->keycode;
272 	input_dev->keycodesize = sizeof(locomokbd_keycode[0]);
273 	input_dev->keycodemax = ARRAY_SIZE(locomokbd_keycode);
274 
275 	input_set_drvdata(input_dev, locomokbd);
276 
277 	memcpy(locomokbd->keycode, locomokbd_keycode, sizeof(locomokbd->keycode));
278 	for (i = 0; i < LOCOMOKBD_NUMKEYS; i++)
279 		set_bit(locomokbd->keycode[i], input_dev->keybit);
280 	clear_bit(0, input_dev->keybit);
281 
282 	/* attempt to get the interrupt */
283 	err = request_irq(dev->irq[0], locomokbd_interrupt, 0, "locomokbd", locomokbd);
284 	if (err) {
285 		printk(KERN_ERR "locomokbd: Can't get irq for keyboard\n");
286 		goto err_release_region;
287 	}
288 
289 	err = input_register_device(locomokbd->input);
290 	if (err)
291 		goto err_free_irq;
292 
293 	return 0;
294 
295  err_free_irq:
296 	free_irq(dev->irq[0], locomokbd);
297  err_release_region:
298 	release_mem_region((unsigned long) dev->mapbase, dev->length);
299 	locomo_set_drvdata(dev, NULL);
300  err_free_mem:
301 	input_free_device(input_dev);
302 	kfree(locomokbd);
303 
304 	return err;
305 }
306 
307 static void locomokbd_remove(struct locomo_dev *dev)
308 {
309 	struct locomokbd *locomokbd = locomo_get_drvdata(dev);
310 
311 	free_irq(dev->irq[0], locomokbd);
312 
313 	timer_shutdown_sync(&locomokbd->timer);
314 
315 	input_unregister_device(locomokbd->input);
316 	locomo_set_drvdata(dev, NULL);
317 
318 	release_mem_region((unsigned long) dev->mapbase, dev->length);
319 
320 	kfree(locomokbd);
321 }
322 
323 static struct locomo_driver keyboard_driver = {
324 	.drv = {
325 		.name = "locomokbd"
326 	},
327 	.devid	= LOCOMO_DEVID_KEYBOARD,
328 	.probe	= locomokbd_probe,
329 	.remove	= locomokbd_remove,
330 };
331 
332 static int __init locomokbd_init(void)
333 {
334 	return locomo_driver_register(&keyboard_driver);
335 }
336 
337 static void __exit locomokbd_exit(void)
338 {
339 	locomo_driver_unregister(&keyboard_driver);
340 }
341 
342 module_init(locomokbd_init);
343 module_exit(locomokbd_exit);
344