xref: /linux/drivers/auxdisplay/panel.c (revision 55f1b540d893da740a81200450014c45a8103f54)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Front panel driver for Linux
4  * Copyright (C) 2000-2008, Willy Tarreau <w@1wt.eu>
5  * Copyright (C) 2016-2017 Glider bvba
6  *
7  * This code drives an LCD module (/dev/lcd), and a keypad (/dev/keypad)
8  * connected to a parallel printer port.
9  *
10  * The LCD module may either be an HD44780-like 8-bit parallel LCD, or a 1-bit
11  * serial module compatible with Samsung's KS0074. The pins may be connected in
12  * any combination, everything is programmable.
13  *
14  * The keypad consists in a matrix of push buttons connecting input pins to
15  * data output pins or to the ground. The combinations have to be hard-coded
16  * in the driver, though several profiles exist and adding new ones is easy.
17  *
18  * Several profiles are provided for commonly found LCD+keypad modules on the
19  * market, such as those found in Nexcom's appliances.
20  *
21  * FIXME:
22  *      - the initialization/deinitialization process is very dirty and should
23  *        be rewritten. It may even be buggy.
24  *
25  * TODO:
26  *	- document 24 keys keyboard (3 rows of 8 cols, 32 diodes + 2 inputs)
27  *      - make the LCD a part of a virtual screen of Vx*Vy
28  *	- make the inputs list smp-safe
29  *      - change the keyboard to a double mapping : signals -> key_id -> values
30  *        so that applications can change values without knowing signals
31  *
32  */
33 
34 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
35 
36 #include <linux/module.h>
37 
38 #include <linux/types.h>
39 #include <linux/errno.h>
40 #include <linux/signal.h>
41 #include <linux/sched.h>
42 #include <linux/spinlock.h>
43 #include <linux/interrupt.h>
44 #include <linux/miscdevice.h>
45 #include <linux/slab.h>
46 #include <linux/ioport.h>
47 #include <linux/fcntl.h>
48 #include <linux/init.h>
49 #include <linux/delay.h>
50 #include <linux/kernel.h>
51 #include <linux/ctype.h>
52 #include <linux/parport.h>
53 #include <linux/list.h>
54 
55 #include <linux/io.h>
56 #include <linux/uaccess.h>
57 
58 #include "charlcd.h"
59 #include "hd44780_common.h"
60 
61 #define LCD_MAXBYTES		256	/* max burst write */
62 
63 #define KEYPAD_BUFFER		64
64 
65 /* poll the keyboard this every second */
66 #define INPUT_POLL_TIME		(HZ / 50)
67 /* a key starts to repeat after this times INPUT_POLL_TIME */
68 #define KEYPAD_REP_START	(10)
69 /* a key repeats this times INPUT_POLL_TIME */
70 #define KEYPAD_REP_DELAY	(2)
71 
72 /* converts an r_str() input to an active high, bits string : 000BAOSE */
73 #define PNL_PINPUT(a)		((((unsigned char)(a)) ^ 0x7F) >> 3)
74 
75 #define PNL_PBUSY		0x80	/* inverted input, active low */
76 #define PNL_PACK		0x40	/* direct input, active low */
77 #define PNL_POUTPA		0x20	/* direct input, active high */
78 #define PNL_PSELECD		0x10	/* direct input, active high */
79 #define PNL_PERRORP		0x08	/* direct input, active low */
80 
81 #define PNL_PBIDIR		0x20	/* bi-directional ports */
82 /* high to read data in or-ed with data out */
83 #define PNL_PINTEN		0x10
84 #define PNL_PSELECP		0x08	/* inverted output, active low */
85 #define PNL_PINITP		0x04	/* direct output, active low */
86 #define PNL_PAUTOLF		0x02	/* inverted output, active low */
87 #define PNL_PSTROBE		0x01	/* inverted output */
88 
89 #define PNL_PD0			0x01
90 #define PNL_PD1			0x02
91 #define PNL_PD2			0x04
92 #define PNL_PD3			0x08
93 #define PNL_PD4			0x10
94 #define PNL_PD5			0x20
95 #define PNL_PD6			0x40
96 #define PNL_PD7			0x80
97 
98 #define PIN_NONE		0
99 #define PIN_STROBE		1
100 #define PIN_D0			2
101 #define PIN_D1			3
102 #define PIN_D2			4
103 #define PIN_D3			5
104 #define PIN_D4			6
105 #define PIN_D5			7
106 #define PIN_D6			8
107 #define PIN_D7			9
108 #define PIN_AUTOLF		14
109 #define PIN_INITP		16
110 #define PIN_SELECP		17
111 #define PIN_NOT_SET		127
112 
113 #define NOT_SET			-1
114 
115 /* macros to simplify use of the parallel port */
116 #define r_ctr(x)        (parport_read_control((x)->port))
117 #define r_dtr(x)        (parport_read_data((x)->port))
118 #define r_str(x)        (parport_read_status((x)->port))
119 #define w_ctr(x, y)     (parport_write_control((x)->port, (y)))
120 #define w_dtr(x, y)     (parport_write_data((x)->port, (y)))
121 
122 /* this defines which bits are to be used and which ones to be ignored */
123 /* logical or of the output bits involved in the scan matrix */
124 static __u8 scan_mask_o;
125 /* logical or of the input bits involved in the scan matrix */
126 static __u8 scan_mask_i;
127 
128 enum input_type {
129 	INPUT_TYPE_STD,
130 	INPUT_TYPE_KBD,
131 };
132 
133 enum input_state {
134 	INPUT_ST_LOW,
135 	INPUT_ST_RISING,
136 	INPUT_ST_HIGH,
137 	INPUT_ST_FALLING,
138 };
139 
140 struct logical_input {
141 	struct list_head list;
142 	__u64 mask;
143 	__u64 value;
144 	enum input_type type;
145 	enum input_state state;
146 	__u8 rise_time, fall_time;
147 	__u8 rise_timer, fall_timer, high_timer;
148 
149 	union {
150 		struct {	/* valid when type == INPUT_TYPE_STD */
151 			void (*press_fct)(int);
152 			void (*release_fct)(int);
153 			int press_data;
154 			int release_data;
155 		} std;
156 		struct {	/* valid when type == INPUT_TYPE_KBD */
157 			char press_str[sizeof(void *) + sizeof(int)] __nonstring;
158 			char repeat_str[sizeof(void *) + sizeof(int)] __nonstring;
159 			char release_str[sizeof(void *) + sizeof(int)] __nonstring;
160 		} kbd;
161 	} u;
162 };
163 
164 static LIST_HEAD(logical_inputs);	/* list of all defined logical inputs */
165 
166 /* physical contacts history
167  * Physical contacts are a 45 bits string of 9 groups of 5 bits each.
168  * The 8 lower groups correspond to output bits 0 to 7, and the 9th group
169  * corresponds to the ground.
170  * Within each group, bits are stored in the same order as read on the port :
171  * BAPSE (busy=4, ack=3, paper empty=2, select=1, error=0).
172  * So, each __u64 is represented like this :
173  * 0000000000000000000BAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSEBAPSE
174  * <-----unused------><gnd><d07><d06><d05><d04><d03><d02><d01><d00>
175  */
176 
177 /* what has just been read from the I/O ports */
178 static __u64 phys_read;
179 /* previous phys_read */
180 static __u64 phys_read_prev;
181 /* stabilized phys_read (phys_read|phys_read_prev) */
182 static __u64 phys_curr;
183 /* previous phys_curr */
184 static __u64 phys_prev;
185 /* 0 means that at least one logical signal needs be computed */
186 static char inputs_stable;
187 
188 /* these variables are specific to the keypad */
189 static struct {
190 	bool enabled;
191 } keypad;
192 
193 static char keypad_buffer[KEYPAD_BUFFER];
194 static int keypad_buflen;
195 static int keypad_start;
196 static char keypressed;
197 static wait_queue_head_t keypad_read_wait;
198 
199 /* lcd-specific variables */
200 static struct {
201 	bool enabled;
202 	bool initialized;
203 
204 	int charset;
205 	int proto;
206 
207 	/* TODO: use union here? */
208 	struct {
209 		int e;
210 		int rs;
211 		int rw;
212 		int cl;
213 		int da;
214 		int bl;
215 	} pins;
216 
217 	struct charlcd *charlcd;
218 } lcd;
219 
220 /* Needed only for init */
221 static int selected_lcd_type = NOT_SET;
222 
223 /*
224  * Bit masks to convert LCD signals to parallel port outputs.
225  * _d_ are values for data port, _c_ are for control port.
226  * [0] = signal OFF, [1] = signal ON, [2] = mask
227  */
228 #define BIT_CLR		0
229 #define BIT_SET		1
230 #define BIT_MSK		2
231 #define BIT_STATES	3
232 /*
233  * one entry for each bit on the LCD
234  */
235 #define LCD_BIT_E	0
236 #define LCD_BIT_RS	1
237 #define LCD_BIT_RW	2
238 #define LCD_BIT_BL	3
239 #define LCD_BIT_CL	4
240 #define LCD_BIT_DA	5
241 #define LCD_BITS	6
242 
243 /*
244  * each bit can be either connected to a DATA or CTRL port
245  */
246 #define LCD_PORT_C	0
247 #define LCD_PORT_D	1
248 #define LCD_PORTS	2
249 
250 static unsigned char lcd_bits[LCD_PORTS][LCD_BITS][BIT_STATES];
251 
252 /*
253  * LCD protocols
254  */
255 #define LCD_PROTO_PARALLEL      0
256 #define LCD_PROTO_SERIAL        1
257 #define LCD_PROTO_TI_DA8XX_LCD	2
258 
259 /*
260  * LCD character sets
261  */
262 #define LCD_CHARSET_NORMAL      0
263 #define LCD_CHARSET_KS0074      1
264 
265 /*
266  * LCD types
267  */
268 #define LCD_TYPE_NONE		0
269 #define LCD_TYPE_CUSTOM		1
270 #define LCD_TYPE_OLD		2
271 #define LCD_TYPE_KS0074		3
272 #define LCD_TYPE_HANTRONIX	4
273 #define LCD_TYPE_NEXCOM		5
274 
275 /*
276  * keypad types
277  */
278 #define KEYPAD_TYPE_NONE	0
279 #define KEYPAD_TYPE_OLD		1
280 #define KEYPAD_TYPE_NEW		2
281 #define KEYPAD_TYPE_NEXCOM	3
282 
283 /*
284  * panel profiles
285  */
286 #define PANEL_PROFILE_CUSTOM	0
287 #define PANEL_PROFILE_OLD	1
288 #define PANEL_PROFILE_NEW	2
289 #define PANEL_PROFILE_HANTRONIX	3
290 #define PANEL_PROFILE_NEXCOM	4
291 #define PANEL_PROFILE_LARGE	5
292 
293 /*
294  * Construct custom config from the kernel's configuration
295  */
296 #define DEFAULT_PARPORT         0
297 #define DEFAULT_PROFILE         PANEL_PROFILE_LARGE
298 #define DEFAULT_KEYPAD_TYPE     KEYPAD_TYPE_OLD
299 #define DEFAULT_LCD_TYPE        LCD_TYPE_OLD
300 #define DEFAULT_LCD_HEIGHT      2
301 #define DEFAULT_LCD_WIDTH       40
302 #define DEFAULT_LCD_CHARSET     LCD_CHARSET_NORMAL
303 #define DEFAULT_LCD_PROTO       LCD_PROTO_PARALLEL
304 
305 #define DEFAULT_LCD_PIN_E       PIN_AUTOLF
306 #define DEFAULT_LCD_PIN_RS      PIN_SELECP
307 #define DEFAULT_LCD_PIN_RW      PIN_INITP
308 #define DEFAULT_LCD_PIN_SCL     PIN_STROBE
309 #define DEFAULT_LCD_PIN_SDA     PIN_D0
310 #define DEFAULT_LCD_PIN_BL      PIN_NOT_SET
311 
312 #ifdef CONFIG_PANEL_PARPORT
313 #undef DEFAULT_PARPORT
314 #define DEFAULT_PARPORT CONFIG_PANEL_PARPORT
315 #endif
316 
317 #ifdef CONFIG_PANEL_PROFILE
318 #undef DEFAULT_PROFILE
319 #define DEFAULT_PROFILE CONFIG_PANEL_PROFILE
320 #endif
321 
322 #if DEFAULT_PROFILE == 0	/* custom */
323 #ifdef CONFIG_PANEL_KEYPAD
324 #undef DEFAULT_KEYPAD_TYPE
325 #define DEFAULT_KEYPAD_TYPE CONFIG_PANEL_KEYPAD
326 #endif
327 
328 #ifdef CONFIG_PANEL_LCD
329 #undef DEFAULT_LCD_TYPE
330 #define DEFAULT_LCD_TYPE CONFIG_PANEL_LCD
331 #endif
332 
333 #ifdef CONFIG_PANEL_LCD_HEIGHT
334 #undef DEFAULT_LCD_HEIGHT
335 #define DEFAULT_LCD_HEIGHT CONFIG_PANEL_LCD_HEIGHT
336 #endif
337 
338 #ifdef CONFIG_PANEL_LCD_WIDTH
339 #undef DEFAULT_LCD_WIDTH
340 #define DEFAULT_LCD_WIDTH CONFIG_PANEL_LCD_WIDTH
341 #endif
342 
343 #ifdef CONFIG_PANEL_LCD_BWIDTH
344 #undef DEFAULT_LCD_BWIDTH
345 #define DEFAULT_LCD_BWIDTH CONFIG_PANEL_LCD_BWIDTH
346 #endif
347 
348 #ifdef CONFIG_PANEL_LCD_HWIDTH
349 #undef DEFAULT_LCD_HWIDTH
350 #define DEFAULT_LCD_HWIDTH CONFIG_PANEL_LCD_HWIDTH
351 #endif
352 
353 #ifdef CONFIG_PANEL_LCD_CHARSET
354 #undef DEFAULT_LCD_CHARSET
355 #define DEFAULT_LCD_CHARSET CONFIG_PANEL_LCD_CHARSET
356 #endif
357 
358 #ifdef CONFIG_PANEL_LCD_PROTO
359 #undef DEFAULT_LCD_PROTO
360 #define DEFAULT_LCD_PROTO CONFIG_PANEL_LCD_PROTO
361 #endif
362 
363 #ifdef CONFIG_PANEL_LCD_PIN_E
364 #undef DEFAULT_LCD_PIN_E
365 #define DEFAULT_LCD_PIN_E CONFIG_PANEL_LCD_PIN_E
366 #endif
367 
368 #ifdef CONFIG_PANEL_LCD_PIN_RS
369 #undef DEFAULT_LCD_PIN_RS
370 #define DEFAULT_LCD_PIN_RS CONFIG_PANEL_LCD_PIN_RS
371 #endif
372 
373 #ifdef CONFIG_PANEL_LCD_PIN_RW
374 #undef DEFAULT_LCD_PIN_RW
375 #define DEFAULT_LCD_PIN_RW CONFIG_PANEL_LCD_PIN_RW
376 #endif
377 
378 #ifdef CONFIG_PANEL_LCD_PIN_SCL
379 #undef DEFAULT_LCD_PIN_SCL
380 #define DEFAULT_LCD_PIN_SCL CONFIG_PANEL_LCD_PIN_SCL
381 #endif
382 
383 #ifdef CONFIG_PANEL_LCD_PIN_SDA
384 #undef DEFAULT_LCD_PIN_SDA
385 #define DEFAULT_LCD_PIN_SDA CONFIG_PANEL_LCD_PIN_SDA
386 #endif
387 
388 #ifdef CONFIG_PANEL_LCD_PIN_BL
389 #undef DEFAULT_LCD_PIN_BL
390 #define DEFAULT_LCD_PIN_BL CONFIG_PANEL_LCD_PIN_BL
391 #endif
392 
393 #endif /* DEFAULT_PROFILE == 0 */
394 
395 /* global variables */
396 
397 /* Device single-open policy control */
398 static atomic_t keypad_available = ATOMIC_INIT(1);
399 
400 static struct pardevice *pprt;
401 
402 static int keypad_initialized;
403 
404 static DEFINE_SPINLOCK(pprt_lock);
405 static struct timer_list scan_timer;
406 
407 MODULE_DESCRIPTION("Generic parallel port LCD/Keypad driver");
408 
409 static int parport = DEFAULT_PARPORT;
410 module_param(parport, int, 0000);
411 MODULE_PARM_DESC(parport, "Parallel port index (0=lpt1, 1=lpt2, ...)");
412 
413 static int profile = DEFAULT_PROFILE;
414 module_param(profile, int, 0000);
415 MODULE_PARM_DESC(profile,
416 		 "1=16x2 old kp; 2=serial 16x2, new kp; 3=16x2 hantronix; "
417 		 "4=16x2 nexcom; default=40x2, old kp");
418 
419 static int keypad_type = NOT_SET;
420 module_param(keypad_type, int, 0000);
421 MODULE_PARM_DESC(keypad_type,
422 		 "Keypad type: 0=none, 1=old 6 keys, 2=new 6+1 keys, 3=nexcom 4 keys");
423 
424 static int lcd_type = NOT_SET;
425 module_param(lcd_type, int, 0000);
426 MODULE_PARM_DESC(lcd_type,
427 		 "LCD type: 0=none, 1=compiled-in, 2=old, 3=serial ks0074, 4=hantronix, 5=nexcom");
428 
429 static int lcd_height = NOT_SET;
430 module_param(lcd_height, int, 0000);
431 MODULE_PARM_DESC(lcd_height, "Number of lines on the LCD");
432 
433 static int lcd_width = NOT_SET;
434 module_param(lcd_width, int, 0000);
435 MODULE_PARM_DESC(lcd_width, "Number of columns on the LCD");
436 
437 static int lcd_bwidth = NOT_SET;	/* internal buffer width (usually 40) */
438 module_param(lcd_bwidth, int, 0000);
439 MODULE_PARM_DESC(lcd_bwidth, "Internal LCD line width (40)");
440 
441 static int lcd_hwidth = NOT_SET;	/* hardware buffer width (usually 64) */
442 module_param(lcd_hwidth, int, 0000);
443 MODULE_PARM_DESC(lcd_hwidth, "LCD line hardware address (64)");
444 
445 static int lcd_charset = NOT_SET;
446 module_param(lcd_charset, int, 0000);
447 MODULE_PARM_DESC(lcd_charset, "LCD character set: 0=standard, 1=KS0074");
448 
449 static int lcd_proto = NOT_SET;
450 module_param(lcd_proto, int, 0000);
451 MODULE_PARM_DESC(lcd_proto,
452 		 "LCD communication: 0=parallel (//), 1=serial, 2=TI LCD Interface");
453 
454 /*
455  * These are the parallel port pins the LCD control signals are connected to.
456  * Set this to 0 if the signal is not used. Set it to its opposite value
457  * (negative) if the signal is negated. -MAXINT is used to indicate that the
458  * pin has not been explicitly specified.
459  *
460  * WARNING! no check will be performed about collisions with keypad !
461  */
462 
463 static int lcd_e_pin  = PIN_NOT_SET;
464 module_param(lcd_e_pin, int, 0000);
465 MODULE_PARM_DESC(lcd_e_pin,
466 		 "# of the // port pin connected to LCD 'E' signal, with polarity (-17..17)");
467 
468 static int lcd_rs_pin = PIN_NOT_SET;
469 module_param(lcd_rs_pin, int, 0000);
470 MODULE_PARM_DESC(lcd_rs_pin,
471 		 "# of the // port pin connected to LCD 'RS' signal, with polarity (-17..17)");
472 
473 static int lcd_rw_pin = PIN_NOT_SET;
474 module_param(lcd_rw_pin, int, 0000);
475 MODULE_PARM_DESC(lcd_rw_pin,
476 		 "# of the // port pin connected to LCD 'RW' signal, with polarity (-17..17)");
477 
478 static int lcd_cl_pin = PIN_NOT_SET;
479 module_param(lcd_cl_pin, int, 0000);
480 MODULE_PARM_DESC(lcd_cl_pin,
481 		 "# of the // port pin connected to serial LCD 'SCL' signal, with polarity (-17..17)");
482 
483 static int lcd_da_pin = PIN_NOT_SET;
484 module_param(lcd_da_pin, int, 0000);
485 MODULE_PARM_DESC(lcd_da_pin,
486 		 "# of the // port pin connected to serial LCD 'SDA' signal, with polarity (-17..17)");
487 
488 static int lcd_bl_pin = PIN_NOT_SET;
489 module_param(lcd_bl_pin, int, 0000);
490 MODULE_PARM_DESC(lcd_bl_pin,
491 		 "# of the // port pin connected to LCD backlight, with polarity (-17..17)");
492 
493 /* Deprecated module parameters - consider not using them anymore */
494 
495 static int lcd_enabled = NOT_SET;
496 module_param(lcd_enabled, int, 0000);
497 MODULE_PARM_DESC(lcd_enabled, "Deprecated option, use lcd_type instead");
498 
499 static int keypad_enabled = NOT_SET;
500 module_param(keypad_enabled, int, 0000);
501 MODULE_PARM_DESC(keypad_enabled, "Deprecated option, use keypad_type instead");
502 
503 /* for some LCD drivers (ks0074) we need a charset conversion table. */
504 static const unsigned char lcd_char_conv_ks0074[256] = {
505 	/*          0|8   1|9   2|A   3|B   4|C   5|D   6|E   7|F */
506 	/* 0x00 */ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
507 	/* 0x08 */ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
508 	/* 0x10 */ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
509 	/* 0x18 */ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
510 	/* 0x20 */ 0x20, 0x21, 0x22, 0x23, 0xa2, 0x25, 0x26, 0x27,
511 	/* 0x28 */ 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
512 	/* 0x30 */ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
513 	/* 0x38 */ 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
514 	/* 0x40 */ 0xa0, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
515 	/* 0x48 */ 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
516 	/* 0x50 */ 0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
517 	/* 0x58 */ 0x58, 0x59, 0x5a, 0xfa, 0xfb, 0xfc, 0x1d, 0xc4,
518 	/* 0x60 */ 0x96, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
519 	/* 0x68 */ 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
520 	/* 0x70 */ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
521 	/* 0x78 */ 0x78, 0x79, 0x7a, 0xfd, 0xfe, 0xff, 0xce, 0x20,
522 	/* 0x80 */ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
523 	/* 0x88 */ 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
524 	/* 0x90 */ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
525 	/* 0x98 */ 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
526 	/* 0xA0 */ 0x20, 0x40, 0xb1, 0xa1, 0x24, 0xa3, 0xfe, 0x5f,
527 	/* 0xA8 */ 0x22, 0xc8, 0x61, 0x14, 0x97, 0x2d, 0xad, 0x96,
528 	/* 0xB0 */ 0x80, 0x8c, 0x82, 0x83, 0x27, 0x8f, 0x86, 0xdd,
529 	/* 0xB8 */ 0x2c, 0x81, 0x6f, 0x15, 0x8b, 0x8a, 0x84, 0x60,
530 	/* 0xC0 */ 0xe2, 0xe2, 0xe2, 0x5b, 0x5b, 0xae, 0xbc, 0xa9,
531 	/* 0xC8 */ 0xc5, 0xbf, 0xc6, 0xf1, 0xe3, 0xe3, 0xe3, 0xe3,
532 	/* 0xD0 */ 0x44, 0x5d, 0xa8, 0xe4, 0xec, 0xec, 0x5c, 0x78,
533 	/* 0xD8 */ 0xab, 0xa6, 0xe5, 0x5e, 0x5e, 0xe6, 0xaa, 0xbe,
534 	/* 0xE0 */ 0x7f, 0xe7, 0xaf, 0x7b, 0x7b, 0xaf, 0xbd, 0xc8,
535 	/* 0xE8 */ 0xa4, 0xa5, 0xc7, 0xf6, 0xa7, 0xe8, 0x69, 0x69,
536 	/* 0xF0 */ 0xed, 0x7d, 0xa8, 0xe4, 0xec, 0x5c, 0x5c, 0x25,
537 	/* 0xF8 */ 0xac, 0xa6, 0xea, 0xef, 0x7e, 0xeb, 0xb2, 0x79,
538 };
539 
540 static const char old_keypad_profile[][4][9] = {
541 	{"S0", "Left\n", "Left\n", ""},
542 	{"S1", "Down\n", "Down\n", ""},
543 	{"S2", "Up\n", "Up\n", ""},
544 	{"S3", "Right\n", "Right\n", ""},
545 	{"S4", "Esc\n", "Esc\n", ""},
546 	{"S5", "Ret\n", "Ret\n", ""},
547 	{"", "", "", ""}
548 };
549 
550 /* signals, press, repeat, release */
551 static const char new_keypad_profile[][4][9] = {
552 	{"S0", "Left\n", "Left\n", ""},
553 	{"S1", "Down\n", "Down\n", ""},
554 	{"S2", "Up\n", "Up\n", ""},
555 	{"S3", "Right\n", "Right\n", ""},
556 	{"S4s5", "", "Esc\n", "Esc\n"},
557 	{"s4S5", "", "Ret\n", "Ret\n"},
558 	{"S4S5", "Help\n", "", ""},
559 	/* add new signals above this line */
560 	{"", "", "", ""}
561 };
562 
563 /* signals, press, repeat, release */
564 static const char nexcom_keypad_profile[][4][9] = {
565 	{"a-p-e-", "Down\n", "Down\n", ""},
566 	{"a-p-E-", "Ret\n", "Ret\n", ""},
567 	{"a-P-E-", "Esc\n", "Esc\n", ""},
568 	{"a-P-e-", "Up\n", "Up\n", ""},
569 	/* add new signals above this line */
570 	{"", "", "", ""}
571 };
572 
573 static const char (*keypad_profile)[4][9] = old_keypad_profile;
574 
575 static DECLARE_BITMAP(bits, LCD_BITS);
576 
577 static void lcd_get_bits(unsigned int port, int *val)
578 {
579 	unsigned int bit, state;
580 
581 	for (bit = 0; bit < LCD_BITS; bit++) {
582 		state = test_bit(bit, bits) ? BIT_SET : BIT_CLR;
583 		*val &= lcd_bits[port][bit][BIT_MSK];
584 		*val |= lcd_bits[port][bit][state];
585 	}
586 }
587 
588 /* sets data port bits according to current signals values */
589 static int set_data_bits(void)
590 {
591 	int val;
592 
593 	val = r_dtr(pprt);
594 	lcd_get_bits(LCD_PORT_D, &val);
595 	w_dtr(pprt, val);
596 	return val;
597 }
598 
599 /* sets ctrl port bits according to current signals values */
600 static int set_ctrl_bits(void)
601 {
602 	int val;
603 
604 	val = r_ctr(pprt);
605 	lcd_get_bits(LCD_PORT_C, &val);
606 	w_ctr(pprt, val);
607 	return val;
608 }
609 
610 /* sets ctrl & data port bits according to current signals values */
611 static void panel_set_bits(void)
612 {
613 	set_data_bits();
614 	set_ctrl_bits();
615 }
616 
617 /*
618  * Converts a parallel port pin (from -25 to 25) to data and control ports
619  * masks, and data and control port bits. The signal will be considered
620  * unconnected if it's on pin 0 or an invalid pin (<-25 or >25).
621  *
622  * Result will be used this way :
623  *   out(dport, in(dport) & d_val[2] | d_val[signal_state])
624  *   out(cport, in(cport) & c_val[2] | c_val[signal_state])
625  */
626 static void pin_to_bits(int pin, unsigned char *d_val, unsigned char *c_val)
627 {
628 	int d_bit, c_bit, inv;
629 
630 	d_val[0] = 0;
631 	c_val[0] = 0;
632 	d_val[1] = 0;
633 	c_val[1] = 0;
634 	d_val[2] = 0xFF;
635 	c_val[2] = 0xFF;
636 
637 	if (pin == 0)
638 		return;
639 
640 	inv = (pin < 0);
641 	if (inv)
642 		pin = -pin;
643 
644 	d_bit = 0;
645 	c_bit = 0;
646 
647 	switch (pin) {
648 	case PIN_STROBE:	/* strobe, inverted */
649 		c_bit = PNL_PSTROBE;
650 		inv = !inv;
651 		break;
652 	case PIN_D0...PIN_D7:	/* D0 - D7 = 2 - 9 */
653 		d_bit = 1 << (pin - 2);
654 		break;
655 	case PIN_AUTOLF:	/* autofeed, inverted */
656 		c_bit = PNL_PAUTOLF;
657 		inv = !inv;
658 		break;
659 	case PIN_INITP:		/* init, direct */
660 		c_bit = PNL_PINITP;
661 		break;
662 	case PIN_SELECP:	/* select_in, inverted */
663 		c_bit = PNL_PSELECP;
664 		inv = !inv;
665 		break;
666 	default:		/* unknown pin, ignore */
667 		break;
668 	}
669 
670 	if (c_bit) {
671 		c_val[2] &= ~c_bit;
672 		c_val[!inv] = c_bit;
673 	} else if (d_bit) {
674 		d_val[2] &= ~d_bit;
675 		d_val[!inv] = d_bit;
676 	}
677 }
678 
679 /*
680  * send a serial byte to the LCD panel. The caller is responsible for locking
681  * if needed.
682  */
683 static void lcd_send_serial(int byte)
684 {
685 	int bit;
686 
687 	/*
688 	 * the data bit is set on D0, and the clock on STROBE.
689 	 * LCD reads D0 on STROBE's rising edge.
690 	 */
691 	for (bit = 0; bit < 8; bit++) {
692 		clear_bit(LCD_BIT_CL, bits);	/* CLK low */
693 		panel_set_bits();
694 		if (byte & 1) {
695 			set_bit(LCD_BIT_DA, bits);
696 		} else {
697 			clear_bit(LCD_BIT_DA, bits);
698 		}
699 
700 		panel_set_bits();
701 		udelay(2);  /* maintain the data during 2 us before CLK up */
702 		set_bit(LCD_BIT_CL, bits);	/* CLK high */
703 		panel_set_bits();
704 		udelay(1);  /* maintain the strobe during 1 us */
705 		byte >>= 1;
706 	}
707 }
708 
709 /* turn the backlight on or off */
710 static void lcd_backlight(struct charlcd *charlcd, enum charlcd_onoff on)
711 {
712 	if (lcd.pins.bl == PIN_NONE)
713 		return;
714 
715 	/* The backlight is activated by setting the AUTOFEED line to +5V  */
716 	spin_lock_irq(&pprt_lock);
717 	if (on)
718 		set_bit(LCD_BIT_BL, bits);
719 	else
720 		clear_bit(LCD_BIT_BL, bits);
721 	panel_set_bits();
722 	spin_unlock_irq(&pprt_lock);
723 }
724 
725 /* send a command to the LCD panel in serial mode */
726 static void lcd_write_cmd_s(struct hd44780_common *hdc, int cmd)
727 {
728 	spin_lock_irq(&pprt_lock);
729 	lcd_send_serial(0x1F);	/* R/W=W, RS=0 */
730 	lcd_send_serial(cmd & 0x0F);
731 	lcd_send_serial((cmd >> 4) & 0x0F);
732 	udelay(40);		/* the shortest command takes at least 40 us */
733 	spin_unlock_irq(&pprt_lock);
734 }
735 
736 /* send data to the LCD panel in serial mode */
737 static void lcd_write_data_s(struct hd44780_common *hdc, int data)
738 {
739 	spin_lock_irq(&pprt_lock);
740 	lcd_send_serial(0x5F);	/* R/W=W, RS=1 */
741 	lcd_send_serial(data & 0x0F);
742 	lcd_send_serial((data >> 4) & 0x0F);
743 	udelay(40);		/* the shortest data takes at least 40 us */
744 	spin_unlock_irq(&pprt_lock);
745 }
746 
747 /* send a command to the LCD panel in 8 bits parallel mode */
748 static void lcd_write_cmd_p8(struct hd44780_common *hdc, int cmd)
749 {
750 	spin_lock_irq(&pprt_lock);
751 	/* present the data to the data port */
752 	w_dtr(pprt, cmd);
753 	udelay(20);	/* maintain the data during 20 us before the strobe */
754 
755 	set_bit(LCD_BIT_E, bits);
756 	clear_bit(LCD_BIT_RS, bits);
757 	clear_bit(LCD_BIT_RW, bits);
758 	set_ctrl_bits();
759 
760 	udelay(40);	/* maintain the strobe during 40 us */
761 
762 	clear_bit(LCD_BIT_E, bits);
763 	set_ctrl_bits();
764 
765 	udelay(120);	/* the shortest command takes at least 120 us */
766 	spin_unlock_irq(&pprt_lock);
767 }
768 
769 /* send data to the LCD panel in 8 bits parallel mode */
770 static void lcd_write_data_p8(struct hd44780_common *hdc, int data)
771 {
772 	spin_lock_irq(&pprt_lock);
773 	/* present the data to the data port */
774 	w_dtr(pprt, data);
775 	udelay(20);	/* maintain the data during 20 us before the strobe */
776 
777 	set_bit(LCD_BIT_E, bits);
778 	set_bit(LCD_BIT_RS, bits);
779 	clear_bit(LCD_BIT_RW, bits);
780 	set_ctrl_bits();
781 
782 	udelay(40);	/* maintain the strobe during 40 us */
783 
784 	clear_bit(LCD_BIT_E, bits);
785 	set_ctrl_bits();
786 
787 	udelay(45);	/* the shortest data takes at least 45 us */
788 	spin_unlock_irq(&pprt_lock);
789 }
790 
791 /* send a command to the TI LCD panel */
792 static void lcd_write_cmd_tilcd(struct hd44780_common *hdc, int cmd)
793 {
794 	spin_lock_irq(&pprt_lock);
795 	/* present the data to the control port */
796 	w_ctr(pprt, cmd);
797 	udelay(60);
798 	spin_unlock_irq(&pprt_lock);
799 }
800 
801 /* send data to the TI LCD panel */
802 static void lcd_write_data_tilcd(struct hd44780_common *hdc, int data)
803 {
804 	spin_lock_irq(&pprt_lock);
805 	/* present the data to the data port */
806 	w_dtr(pprt, data);
807 	udelay(60);
808 	spin_unlock_irq(&pprt_lock);
809 }
810 
811 static const struct charlcd_ops charlcd_ops = {
812 	.backlight	= lcd_backlight,
813 	.print		= hd44780_common_print,
814 	.gotoxy		= hd44780_common_gotoxy,
815 	.home		= hd44780_common_home,
816 	.clear_display	= hd44780_common_clear_display,
817 	.init_display	= hd44780_common_init_display,
818 	.shift_cursor	= hd44780_common_shift_cursor,
819 	.shift_display	= hd44780_common_shift_display,
820 	.display	= hd44780_common_display,
821 	.cursor		= hd44780_common_cursor,
822 	.blink		= hd44780_common_blink,
823 	.fontsize	= hd44780_common_fontsize,
824 	.lines		= hd44780_common_lines,
825 	.redefine_char	= hd44780_common_redefine_char,
826 };
827 
828 /* initialize the LCD driver */
829 static void lcd_init(void)
830 {
831 	struct charlcd *charlcd;
832 	struct hd44780_common *hdc;
833 
834 	hdc = hd44780_common_alloc();
835 	if (!hdc)
836 		return;
837 
838 	charlcd = charlcd_alloc();
839 	if (!charlcd) {
840 		kfree(hdc);
841 		return;
842 	}
843 
844 	hdc->hd44780 = &lcd;
845 	charlcd->drvdata = hdc;
846 
847 	/*
848 	 * Init lcd struct with load-time values to preserve exact
849 	 * current functionality (at least for now).
850 	 */
851 	charlcd->height = lcd_height;
852 	charlcd->width = lcd_width;
853 	hdc->bwidth = lcd_bwidth;
854 	hdc->hwidth = lcd_hwidth;
855 
856 	switch (selected_lcd_type) {
857 	case LCD_TYPE_OLD:
858 		/* parallel mode, 8 bits */
859 		lcd.proto = LCD_PROTO_PARALLEL;
860 		lcd.charset = LCD_CHARSET_NORMAL;
861 		lcd.pins.e = PIN_STROBE;
862 		lcd.pins.rs = PIN_AUTOLF;
863 
864 		charlcd->width = 40;
865 		hdc->bwidth = 40;
866 		hdc->hwidth = 64;
867 		charlcd->height = 2;
868 		break;
869 	case LCD_TYPE_KS0074:
870 		/* serial mode, ks0074 */
871 		lcd.proto = LCD_PROTO_SERIAL;
872 		lcd.charset = LCD_CHARSET_KS0074;
873 		lcd.pins.bl = PIN_AUTOLF;
874 		lcd.pins.cl = PIN_STROBE;
875 		lcd.pins.da = PIN_D0;
876 
877 		charlcd->width = 16;
878 		hdc->bwidth = 40;
879 		hdc->hwidth = 16;
880 		charlcd->height = 2;
881 		break;
882 	case LCD_TYPE_NEXCOM:
883 		/* parallel mode, 8 bits, generic */
884 		lcd.proto = LCD_PROTO_PARALLEL;
885 		lcd.charset = LCD_CHARSET_NORMAL;
886 		lcd.pins.e = PIN_AUTOLF;
887 		lcd.pins.rs = PIN_SELECP;
888 		lcd.pins.rw = PIN_INITP;
889 
890 		charlcd->width = 16;
891 		hdc->bwidth = 40;
892 		hdc->hwidth = 64;
893 		charlcd->height = 2;
894 		break;
895 	case LCD_TYPE_CUSTOM:
896 		/* customer-defined */
897 		lcd.proto = DEFAULT_LCD_PROTO;
898 		lcd.charset = DEFAULT_LCD_CHARSET;
899 		/* default geometry will be set later */
900 		break;
901 	case LCD_TYPE_HANTRONIX:
902 		/* parallel mode, 8 bits, hantronix-like */
903 	default:
904 		lcd.proto = LCD_PROTO_PARALLEL;
905 		lcd.charset = LCD_CHARSET_NORMAL;
906 		lcd.pins.e = PIN_STROBE;
907 		lcd.pins.rs = PIN_SELECP;
908 
909 		charlcd->width = 16;
910 		hdc->bwidth = 40;
911 		hdc->hwidth = 64;
912 		charlcd->height = 2;
913 		break;
914 	}
915 
916 	/* Overwrite with module params set on loading */
917 	if (lcd_height != NOT_SET)
918 		charlcd->height = lcd_height;
919 	if (lcd_width != NOT_SET)
920 		charlcd->width = lcd_width;
921 	if (lcd_bwidth != NOT_SET)
922 		hdc->bwidth = lcd_bwidth;
923 	if (lcd_hwidth != NOT_SET)
924 		hdc->hwidth = lcd_hwidth;
925 	if (lcd_charset != NOT_SET)
926 		lcd.charset = lcd_charset;
927 	if (lcd_proto != NOT_SET)
928 		lcd.proto = lcd_proto;
929 	if (lcd_e_pin != PIN_NOT_SET)
930 		lcd.pins.e = lcd_e_pin;
931 	if (lcd_rs_pin != PIN_NOT_SET)
932 		lcd.pins.rs = lcd_rs_pin;
933 	if (lcd_rw_pin != PIN_NOT_SET)
934 		lcd.pins.rw = lcd_rw_pin;
935 	if (lcd_cl_pin != PIN_NOT_SET)
936 		lcd.pins.cl = lcd_cl_pin;
937 	if (lcd_da_pin != PIN_NOT_SET)
938 		lcd.pins.da = lcd_da_pin;
939 	if (lcd_bl_pin != PIN_NOT_SET)
940 		lcd.pins.bl = lcd_bl_pin;
941 
942 	/* this is used to catch wrong and default values */
943 	if (charlcd->width <= 0)
944 		charlcd->width = DEFAULT_LCD_WIDTH;
945 	if (hdc->bwidth <= 0)
946 		hdc->bwidth = DEFAULT_LCD_BWIDTH;
947 	if (hdc->hwidth <= 0)
948 		hdc->hwidth = DEFAULT_LCD_HWIDTH;
949 	if (charlcd->height <= 0)
950 		charlcd->height = DEFAULT_LCD_HEIGHT;
951 
952 	if (lcd.proto == LCD_PROTO_SERIAL) {	/* SERIAL */
953 		charlcd->ops = &charlcd_ops;
954 		hdc->write_data = lcd_write_data_s;
955 		hdc->write_cmd = lcd_write_cmd_s;
956 
957 		if (lcd.pins.cl == PIN_NOT_SET)
958 			lcd.pins.cl = DEFAULT_LCD_PIN_SCL;
959 		if (lcd.pins.da == PIN_NOT_SET)
960 			lcd.pins.da = DEFAULT_LCD_PIN_SDA;
961 
962 	} else if (lcd.proto == LCD_PROTO_PARALLEL) {	/* PARALLEL */
963 		charlcd->ops = &charlcd_ops;
964 		hdc->write_data = lcd_write_data_p8;
965 		hdc->write_cmd = lcd_write_cmd_p8;
966 
967 		if (lcd.pins.e == PIN_NOT_SET)
968 			lcd.pins.e = DEFAULT_LCD_PIN_E;
969 		if (lcd.pins.rs == PIN_NOT_SET)
970 			lcd.pins.rs = DEFAULT_LCD_PIN_RS;
971 		if (lcd.pins.rw == PIN_NOT_SET)
972 			lcd.pins.rw = DEFAULT_LCD_PIN_RW;
973 	} else {
974 		charlcd->ops = &charlcd_ops;
975 		hdc->write_data = lcd_write_data_tilcd;
976 		hdc->write_cmd = lcd_write_cmd_tilcd;
977 	}
978 
979 	if (lcd.pins.bl == PIN_NOT_SET)
980 		lcd.pins.bl = DEFAULT_LCD_PIN_BL;
981 
982 	if (lcd.pins.e == PIN_NOT_SET)
983 		lcd.pins.e = PIN_NONE;
984 	if (lcd.pins.rs == PIN_NOT_SET)
985 		lcd.pins.rs = PIN_NONE;
986 	if (lcd.pins.rw == PIN_NOT_SET)
987 		lcd.pins.rw = PIN_NONE;
988 	if (lcd.pins.bl == PIN_NOT_SET)
989 		lcd.pins.bl = PIN_NONE;
990 	if (lcd.pins.cl == PIN_NOT_SET)
991 		lcd.pins.cl = PIN_NONE;
992 	if (lcd.pins.da == PIN_NOT_SET)
993 		lcd.pins.da = PIN_NONE;
994 
995 	if (lcd.charset == NOT_SET)
996 		lcd.charset = DEFAULT_LCD_CHARSET;
997 
998 	if (lcd.charset == LCD_CHARSET_KS0074)
999 		charlcd->char_conv = lcd_char_conv_ks0074;
1000 	else
1001 		charlcd->char_conv = NULL;
1002 
1003 	pin_to_bits(lcd.pins.e, lcd_bits[LCD_PORT_D][LCD_BIT_E],
1004 		    lcd_bits[LCD_PORT_C][LCD_BIT_E]);
1005 	pin_to_bits(lcd.pins.rs, lcd_bits[LCD_PORT_D][LCD_BIT_RS],
1006 		    lcd_bits[LCD_PORT_C][LCD_BIT_RS]);
1007 	pin_to_bits(lcd.pins.rw, lcd_bits[LCD_PORT_D][LCD_BIT_RW],
1008 		    lcd_bits[LCD_PORT_C][LCD_BIT_RW]);
1009 	pin_to_bits(lcd.pins.bl, lcd_bits[LCD_PORT_D][LCD_BIT_BL],
1010 		    lcd_bits[LCD_PORT_C][LCD_BIT_BL]);
1011 	pin_to_bits(lcd.pins.cl, lcd_bits[LCD_PORT_D][LCD_BIT_CL],
1012 		    lcd_bits[LCD_PORT_C][LCD_BIT_CL]);
1013 	pin_to_bits(lcd.pins.da, lcd_bits[LCD_PORT_D][LCD_BIT_DA],
1014 		    lcd_bits[LCD_PORT_C][LCD_BIT_DA]);
1015 
1016 	lcd.charlcd = charlcd;
1017 	lcd.initialized = true;
1018 }
1019 
1020 /*
1021  * These are the file operation function for user access to /dev/keypad
1022  */
1023 
1024 static ssize_t keypad_read(struct file *file,
1025 			   char __user *buf, size_t count, loff_t *ppos)
1026 {
1027 	unsigned i = *ppos;
1028 	char __user *tmp = buf;
1029 
1030 	if (keypad_buflen == 0) {
1031 		if (file->f_flags & O_NONBLOCK)
1032 			return -EAGAIN;
1033 
1034 		if (wait_event_interruptible(keypad_read_wait,
1035 					     keypad_buflen != 0))
1036 			return -EINTR;
1037 	}
1038 
1039 	for (; count-- > 0 && (keypad_buflen > 0);
1040 	     ++i, ++tmp, --keypad_buflen) {
1041 		put_user(keypad_buffer[keypad_start], tmp);
1042 		keypad_start = (keypad_start + 1) % KEYPAD_BUFFER;
1043 	}
1044 	*ppos = i;
1045 
1046 	return tmp - buf;
1047 }
1048 
1049 static int keypad_open(struct inode *inode, struct file *file)
1050 {
1051 	int ret;
1052 
1053 	ret = -EBUSY;
1054 	if (!atomic_dec_and_test(&keypad_available))
1055 		goto fail;	/* open only once at a time */
1056 
1057 	ret = -EPERM;
1058 	if (file->f_mode & FMODE_WRITE)	/* device is read-only */
1059 		goto fail;
1060 
1061 	keypad_buflen = 0;	/* flush the buffer on opening */
1062 	return 0;
1063  fail:
1064 	atomic_inc(&keypad_available);
1065 	return ret;
1066 }
1067 
1068 static int keypad_release(struct inode *inode, struct file *file)
1069 {
1070 	atomic_inc(&keypad_available);
1071 	return 0;
1072 }
1073 
1074 static const struct file_operations keypad_fops = {
1075 	.read    = keypad_read,		/* read */
1076 	.open    = keypad_open,		/* open */
1077 	.release = keypad_release,	/* close */
1078 	.llseek  = default_llseek,
1079 };
1080 
1081 static struct miscdevice keypad_dev = {
1082 	.minor	= KEYPAD_MINOR,
1083 	.name	= "keypad",
1084 	.fops	= &keypad_fops,
1085 };
1086 
1087 static void keypad_send_key(const char *string, int max_len)
1088 {
1089 	/* send the key to the device only if a process is attached to it. */
1090 	if (!atomic_read(&keypad_available)) {
1091 		while (max_len-- && keypad_buflen < KEYPAD_BUFFER && *string) {
1092 			keypad_buffer[(keypad_start + keypad_buflen++) %
1093 				      KEYPAD_BUFFER] = *string++;
1094 		}
1095 		wake_up_interruptible(&keypad_read_wait);
1096 	}
1097 }
1098 
1099 /* this function scans all the bits involving at least one logical signal,
1100  * and puts the results in the bitfield "phys_read" (one bit per established
1101  * contact), and sets "phys_read_prev" to "phys_read".
1102  *
1103  * Note: to debounce input signals, we will only consider as switched a signal
1104  * which is stable across 2 measures. Signals which are different between two
1105  * reads will be kept as they previously were in their logical form (phys_prev).
1106  * A signal which has just switched will have a 1 in
1107  * (phys_read ^ phys_read_prev).
1108  */
1109 static void phys_scan_contacts(void)
1110 {
1111 	int bit, bitval;
1112 	char oldval;
1113 	char bitmask;
1114 	char gndmask;
1115 
1116 	phys_prev = phys_curr;
1117 	phys_read_prev = phys_read;
1118 	phys_read = 0;		/* flush all signals */
1119 
1120 	/* keep track of old value, with all outputs disabled */
1121 	oldval = r_dtr(pprt) | scan_mask_o;
1122 	/* activate all keyboard outputs (active low) */
1123 	w_dtr(pprt, oldval & ~scan_mask_o);
1124 
1125 	/* will have a 1 for each bit set to gnd */
1126 	bitmask = PNL_PINPUT(r_str(pprt)) & scan_mask_i;
1127 	/* disable all matrix signals */
1128 	w_dtr(pprt, oldval);
1129 
1130 	/* now that all outputs are cleared, the only active input bits are
1131 	 * directly connected to the ground
1132 	 */
1133 
1134 	/* 1 for each grounded input */
1135 	gndmask = PNL_PINPUT(r_str(pprt)) & scan_mask_i;
1136 
1137 	/* grounded inputs are signals 40-44 */
1138 	phys_read |= (__u64)gndmask << 40;
1139 
1140 	if (bitmask != gndmask) {
1141 		/*
1142 		 * since clearing the outputs changed some inputs, we know
1143 		 * that some input signals are currently tied to some outputs.
1144 		 * So we'll scan them.
1145 		 */
1146 		for (bit = 0; bit < 8; bit++) {
1147 			bitval = BIT(bit);
1148 
1149 			if (!(scan_mask_o & bitval))	/* skip unused bits */
1150 				continue;
1151 
1152 			w_dtr(pprt, oldval & ~bitval);	/* enable this output */
1153 			bitmask = PNL_PINPUT(r_str(pprt)) & ~gndmask;
1154 			phys_read |= (__u64)bitmask << (5 * bit);
1155 		}
1156 		w_dtr(pprt, oldval);	/* disable all outputs */
1157 	}
1158 	/*
1159 	 * this is easy: use old bits when they are flapping,
1160 	 * use new ones when stable
1161 	 */
1162 	phys_curr = (phys_prev & (phys_read ^ phys_read_prev)) |
1163 		    (phys_read & ~(phys_read ^ phys_read_prev));
1164 }
1165 
1166 static inline int input_state_high(struct logical_input *input)
1167 {
1168 #if 0
1169 	/* FIXME:
1170 	 * this is an invalid test. It tries to catch
1171 	 * transitions from single-key to multiple-key, but
1172 	 * doesn't take into account the contacts polarity.
1173 	 * The only solution to the problem is to parse keys
1174 	 * from the most complex to the simplest combinations,
1175 	 * and mark them as 'caught' once a combination
1176 	 * matches, then unmatch it for all other ones.
1177 	 */
1178 
1179 	/* try to catch dangerous transitions cases :
1180 	 * someone adds a bit, so this signal was a false
1181 	 * positive resulting from a transition. We should
1182 	 * invalidate the signal immediately and not call the
1183 	 * release function.
1184 	 * eg: 0 -(press A)-> A -(press B)-> AB : don't match A's release.
1185 	 */
1186 	if (((phys_prev & input->mask) == input->value) &&
1187 	    ((phys_curr & input->mask) >  input->value)) {
1188 		input->state = INPUT_ST_LOW; /* invalidate */
1189 		return 1;
1190 	}
1191 #endif
1192 
1193 	if ((phys_curr & input->mask) == input->value) {
1194 		if ((input->type == INPUT_TYPE_STD) &&
1195 		    (input->high_timer == 0)) {
1196 			input->high_timer++;
1197 			if (input->u.std.press_fct)
1198 				input->u.std.press_fct(input->u.std.press_data);
1199 		} else if (input->type == INPUT_TYPE_KBD) {
1200 			/* will turn on the light */
1201 			keypressed = 1;
1202 
1203 			if (input->high_timer == 0) {
1204 				char *press_str = input->u.kbd.press_str;
1205 
1206 				if (press_str[0]) {
1207 					int s = sizeof(input->u.kbd.press_str);
1208 
1209 					keypad_send_key(press_str, s);
1210 				}
1211 			}
1212 
1213 			if (input->u.kbd.repeat_str[0]) {
1214 				char *repeat_str = input->u.kbd.repeat_str;
1215 
1216 				if (input->high_timer >= KEYPAD_REP_START) {
1217 					int s = sizeof(input->u.kbd.repeat_str);
1218 
1219 					input->high_timer -= KEYPAD_REP_DELAY;
1220 					keypad_send_key(repeat_str, s);
1221 				}
1222 				/* we will need to come back here soon */
1223 				inputs_stable = 0;
1224 			}
1225 
1226 			if (input->high_timer < 255)
1227 				input->high_timer++;
1228 		}
1229 		return 1;
1230 	}
1231 
1232 	/* else signal falling down. Let's fall through. */
1233 	input->state = INPUT_ST_FALLING;
1234 	input->fall_timer = 0;
1235 
1236 	return 0;
1237 }
1238 
1239 static inline void input_state_falling(struct logical_input *input)
1240 {
1241 #if 0
1242 	/* FIXME !!! same comment as in input_state_high */
1243 	if (((phys_prev & input->mask) == input->value) &&
1244 	    ((phys_curr & input->mask) >  input->value)) {
1245 		input->state = INPUT_ST_LOW;	/* invalidate */
1246 		return;
1247 	}
1248 #endif
1249 
1250 	if ((phys_curr & input->mask) == input->value) {
1251 		if (input->type == INPUT_TYPE_KBD) {
1252 			/* will turn on the light */
1253 			keypressed = 1;
1254 
1255 			if (input->u.kbd.repeat_str[0]) {
1256 				char *repeat_str = input->u.kbd.repeat_str;
1257 
1258 				if (input->high_timer >= KEYPAD_REP_START) {
1259 					int s = sizeof(input->u.kbd.repeat_str);
1260 
1261 					input->high_timer -= KEYPAD_REP_DELAY;
1262 					keypad_send_key(repeat_str, s);
1263 				}
1264 				/* we will need to come back here soon */
1265 				inputs_stable = 0;
1266 			}
1267 
1268 			if (input->high_timer < 255)
1269 				input->high_timer++;
1270 		}
1271 		input->state = INPUT_ST_HIGH;
1272 	} else if (input->fall_timer >= input->fall_time) {
1273 		/* call release event */
1274 		if (input->type == INPUT_TYPE_STD) {
1275 			void (*release_fct)(int) = input->u.std.release_fct;
1276 
1277 			if (release_fct)
1278 				release_fct(input->u.std.release_data);
1279 		} else if (input->type == INPUT_TYPE_KBD) {
1280 			char *release_str = input->u.kbd.release_str;
1281 
1282 			if (release_str[0]) {
1283 				int s = sizeof(input->u.kbd.release_str);
1284 
1285 				keypad_send_key(release_str, s);
1286 			}
1287 		}
1288 
1289 		input->state = INPUT_ST_LOW;
1290 	} else {
1291 		input->fall_timer++;
1292 		inputs_stable = 0;
1293 	}
1294 }
1295 
1296 static void panel_process_inputs(void)
1297 {
1298 	struct logical_input *input;
1299 
1300 	keypressed = 0;
1301 	inputs_stable = 1;
1302 	list_for_each_entry(input, &logical_inputs, list) {
1303 		switch (input->state) {
1304 		case INPUT_ST_LOW:
1305 			if ((phys_curr & input->mask) != input->value)
1306 				break;
1307 			/* if all needed ones were already set previously,
1308 			 * this means that this logical signal has been
1309 			 * activated by the releasing of another combined
1310 			 * signal, so we don't want to match.
1311 			 * eg: AB -(release B)-> A -(release A)-> 0 :
1312 			 *     don't match A.
1313 			 */
1314 			if ((phys_prev & input->mask) == input->value)
1315 				break;
1316 			input->rise_timer = 0;
1317 			input->state = INPUT_ST_RISING;
1318 			fallthrough;
1319 		case INPUT_ST_RISING:
1320 			if ((phys_curr & input->mask) != input->value) {
1321 				input->state = INPUT_ST_LOW;
1322 				break;
1323 			}
1324 			if (input->rise_timer < input->rise_time) {
1325 				inputs_stable = 0;
1326 				input->rise_timer++;
1327 				break;
1328 			}
1329 			input->high_timer = 0;
1330 			input->state = INPUT_ST_HIGH;
1331 			fallthrough;
1332 		case INPUT_ST_HIGH:
1333 			if (input_state_high(input))
1334 				break;
1335 			fallthrough;
1336 		case INPUT_ST_FALLING:
1337 			input_state_falling(input);
1338 		}
1339 	}
1340 }
1341 
1342 static void panel_scan_timer(struct timer_list *unused)
1343 {
1344 	if (keypad.enabled && keypad_initialized) {
1345 		if (spin_trylock_irq(&pprt_lock)) {
1346 			phys_scan_contacts();
1347 
1348 			/* no need for the parport anymore */
1349 			spin_unlock_irq(&pprt_lock);
1350 		}
1351 
1352 		if (!inputs_stable || phys_curr != phys_prev)
1353 			panel_process_inputs();
1354 	}
1355 
1356 	if (keypressed && lcd.enabled && lcd.initialized)
1357 		charlcd_poke(lcd.charlcd);
1358 
1359 	mod_timer(&scan_timer, jiffies + INPUT_POLL_TIME);
1360 }
1361 
1362 static void init_scan_timer(void)
1363 {
1364 	if (scan_timer.function)
1365 		return;		/* already started */
1366 
1367 	timer_setup(&scan_timer, panel_scan_timer, 0);
1368 	scan_timer.expires = jiffies + INPUT_POLL_TIME;
1369 	add_timer(&scan_timer);
1370 }
1371 
1372 /* converts a name of the form "({BbAaPpSsEe}{01234567-})*" to a series of bits.
1373  * if <omask> or <imask> are non-null, they will be or'ed with the bits
1374  * corresponding to out and in bits respectively.
1375  * returns 1 if ok, 0 if error (in which case, nothing is written).
1376  */
1377 static u8 input_name2mask(const char *name, __u64 *mask, __u64 *value,
1378 			  u8 *imask, u8 *omask)
1379 {
1380 	const char sigtab[] = "EeSsPpAaBb";
1381 	u8 im, om;
1382 	__u64 m, v;
1383 
1384 	om = 0;
1385 	im = 0;
1386 	m = 0ULL;
1387 	v = 0ULL;
1388 	while (*name) {
1389 		int in, out, bit, neg;
1390 		const char *idx;
1391 
1392 		idx = strchr(sigtab, *name);
1393 		if (!idx)
1394 			return 0;	/* input name not found */
1395 
1396 		in = idx - sigtab;
1397 		neg = (in & 1);	/* odd (lower) names are negated */
1398 		in >>= 1;
1399 		im |= BIT(in);
1400 
1401 		name++;
1402 		if (*name >= '0' && *name <= '7') {
1403 			out = *name - '0';
1404 			om |= BIT(out);
1405 		} else if (*name == '-') {
1406 			out = 8;
1407 		} else {
1408 			return 0;	/* unknown bit name */
1409 		}
1410 
1411 		bit = (out * 5) + in;
1412 
1413 		m |= 1ULL << bit;
1414 		if (!neg)
1415 			v |= 1ULL << bit;
1416 		name++;
1417 	}
1418 	*mask = m;
1419 	*value = v;
1420 	if (imask)
1421 		*imask |= im;
1422 	if (omask)
1423 		*omask |= om;
1424 	return 1;
1425 }
1426 
1427 /* tries to bind a key to the signal name <name>. The key will send the
1428  * strings <press>, <repeat>, <release> for these respective events.
1429  * Returns the pointer to the new key if ok, NULL if the key could not be bound.
1430  */
1431 static struct logical_input *panel_bind_key(const char *name, const char *press,
1432 					    const char *repeat,
1433 					    const char *release)
1434 {
1435 	struct logical_input *key;
1436 
1437 	key = kzalloc(sizeof(*key), GFP_KERNEL);
1438 	if (!key)
1439 		return NULL;
1440 
1441 	if (!input_name2mask(name, &key->mask, &key->value, &scan_mask_i,
1442 			     &scan_mask_o)) {
1443 		kfree(key);
1444 		return NULL;
1445 	}
1446 
1447 	key->type = INPUT_TYPE_KBD;
1448 	key->state = INPUT_ST_LOW;
1449 	key->rise_time = 1;
1450 	key->fall_time = 1;
1451 
1452 	strtomem_pad(key->u.kbd.press_str, press, '\0');
1453 	strtomem_pad(key->u.kbd.repeat_str, repeat, '\0');
1454 	strtomem_pad(key->u.kbd.release_str, release, '\0');
1455 	list_add(&key->list, &logical_inputs);
1456 	return key;
1457 }
1458 
1459 #if 0
1460 /* tries to bind a callback function to the signal name <name>. The function
1461  * <press_fct> will be called with the <press_data> arg when the signal is
1462  * activated, and so on for <release_fct>/<release_data>
1463  * Returns the pointer to the new signal if ok, NULL if the signal could not
1464  * be bound.
1465  */
1466 static struct logical_input *panel_bind_callback(char *name,
1467 						 void (*press_fct)(int),
1468 						 int press_data,
1469 						 void (*release_fct)(int),
1470 						 int release_data)
1471 {
1472 	struct logical_input *callback;
1473 
1474 	callback = kmalloc(sizeof(*callback), GFP_KERNEL);
1475 	if (!callback)
1476 		return NULL;
1477 
1478 	memset(callback, 0, sizeof(struct logical_input));
1479 	if (!input_name2mask(name, &callback->mask, &callback->value,
1480 			     &scan_mask_i, &scan_mask_o))
1481 		return NULL;
1482 
1483 	callback->type = INPUT_TYPE_STD;
1484 	callback->state = INPUT_ST_LOW;
1485 	callback->rise_time = 1;
1486 	callback->fall_time = 1;
1487 	callback->u.std.press_fct = press_fct;
1488 	callback->u.std.press_data = press_data;
1489 	callback->u.std.release_fct = release_fct;
1490 	callback->u.std.release_data = release_data;
1491 	list_add(&callback->list, &logical_inputs);
1492 	return callback;
1493 }
1494 #endif
1495 
1496 static void keypad_init(void)
1497 {
1498 	int keynum;
1499 
1500 	init_waitqueue_head(&keypad_read_wait);
1501 	keypad_buflen = 0;	/* flushes any eventual noisy keystroke */
1502 
1503 	/* Let's create all known keys */
1504 
1505 	for (keynum = 0; keypad_profile[keynum][0][0]; keynum++) {
1506 		panel_bind_key(keypad_profile[keynum][0],
1507 			       keypad_profile[keynum][1],
1508 			       keypad_profile[keynum][2],
1509 			       keypad_profile[keynum][3]);
1510 	}
1511 
1512 	init_scan_timer();
1513 	keypad_initialized = 1;
1514 }
1515 
1516 /**************************************************/
1517 /* device initialization                          */
1518 /**************************************************/
1519 
1520 static void panel_attach(struct parport *port)
1521 {
1522 	int selected_keypad_type = NOT_SET;
1523 	struct pardev_cb panel_cb;
1524 
1525 	/* take care of an eventual profile */
1526 	switch (profile) {
1527 	case PANEL_PROFILE_CUSTOM:
1528 		/* custom profile */
1529 		selected_keypad_type = DEFAULT_KEYPAD_TYPE;
1530 		selected_lcd_type = DEFAULT_LCD_TYPE;
1531 		break;
1532 	case PANEL_PROFILE_OLD:
1533 		/* 8 bits, 2*16, old keypad */
1534 		selected_keypad_type = KEYPAD_TYPE_OLD;
1535 		selected_lcd_type = LCD_TYPE_OLD;
1536 
1537 		/* TODO: This two are a little hacky, sort it out later */
1538 		if (lcd_width == NOT_SET)
1539 			lcd_width = 16;
1540 		if (lcd_hwidth == NOT_SET)
1541 			lcd_hwidth = 16;
1542 		break;
1543 	case PANEL_PROFILE_NEW:
1544 		/* serial, 2*16, new keypad */
1545 		selected_keypad_type = KEYPAD_TYPE_NEW;
1546 		selected_lcd_type = LCD_TYPE_KS0074;
1547 		break;
1548 	case PANEL_PROFILE_HANTRONIX:
1549 		/* 8 bits, 2*16 hantronix-like, no keypad */
1550 		selected_keypad_type = KEYPAD_TYPE_NONE;
1551 		selected_lcd_type = LCD_TYPE_HANTRONIX;
1552 		break;
1553 	case PANEL_PROFILE_NEXCOM:
1554 		/* generic 8 bits, 2*16, nexcom keypad, eg. Nexcom. */
1555 		selected_keypad_type = KEYPAD_TYPE_NEXCOM;
1556 		selected_lcd_type = LCD_TYPE_NEXCOM;
1557 		break;
1558 	case PANEL_PROFILE_LARGE:
1559 		/* 8 bits, 2*40, old keypad */
1560 		selected_keypad_type = KEYPAD_TYPE_OLD;
1561 		selected_lcd_type = LCD_TYPE_OLD;
1562 		break;
1563 	}
1564 
1565 	/*
1566 	 * Overwrite selection with module param values (both keypad and lcd),
1567 	 * where the deprecated params have lower prio.
1568 	 */
1569 	if (keypad_enabled != NOT_SET)
1570 		selected_keypad_type = keypad_enabled;
1571 	if (keypad_type != NOT_SET)
1572 		selected_keypad_type = keypad_type;
1573 
1574 	keypad.enabled = (selected_keypad_type > 0);
1575 
1576 	if (lcd_enabled != NOT_SET)
1577 		selected_lcd_type = lcd_enabled;
1578 	if (lcd_type != NOT_SET)
1579 		selected_lcd_type = lcd_type;
1580 
1581 	lcd.enabled = (selected_lcd_type > 0);
1582 
1583 	if (lcd.enabled) {
1584 		/*
1585 		 * Init lcd struct with load-time values to preserve exact
1586 		 * current functionality (at least for now).
1587 		 */
1588 		lcd.charset = lcd_charset;
1589 		lcd.proto = lcd_proto;
1590 		lcd.pins.e = lcd_e_pin;
1591 		lcd.pins.rs = lcd_rs_pin;
1592 		lcd.pins.rw = lcd_rw_pin;
1593 		lcd.pins.cl = lcd_cl_pin;
1594 		lcd.pins.da = lcd_da_pin;
1595 		lcd.pins.bl = lcd_bl_pin;
1596 	}
1597 
1598 	switch (selected_keypad_type) {
1599 	case KEYPAD_TYPE_OLD:
1600 		keypad_profile = old_keypad_profile;
1601 		break;
1602 	case KEYPAD_TYPE_NEW:
1603 		keypad_profile = new_keypad_profile;
1604 		break;
1605 	case KEYPAD_TYPE_NEXCOM:
1606 		keypad_profile = nexcom_keypad_profile;
1607 		break;
1608 	default:
1609 		keypad_profile = NULL;
1610 		break;
1611 	}
1612 
1613 	if (!lcd.enabled && !keypad.enabled) {
1614 		/* no device enabled, let's exit */
1615 		pr_err("panel driver disabled.\n");
1616 		return;
1617 	}
1618 
1619 	if (port->number != parport)
1620 		return;
1621 
1622 	if (pprt) {
1623 		pr_err("%s: port->number=%d parport=%d, already registered!\n",
1624 		       __func__, port->number, parport);
1625 		return;
1626 	}
1627 
1628 	memset(&panel_cb, 0, sizeof(panel_cb));
1629 	panel_cb.private = &pprt;
1630 	/* panel_cb.flags = 0 should be PARPORT_DEV_EXCL? */
1631 
1632 	pprt = parport_register_dev_model(port, "panel", &panel_cb, 0);
1633 	if (!pprt) {
1634 		pr_err("%s: port->number=%d parport=%d, parport_register_device() failed\n",
1635 		       __func__, port->number, parport);
1636 		return;
1637 	}
1638 
1639 	if (parport_claim(pprt)) {
1640 		pr_err("could not claim access to parport%d. Aborting.\n",
1641 		       parport);
1642 		goto err_unreg_device;
1643 	}
1644 
1645 	/* must init LCD first, just in case an IRQ from the keypad is
1646 	 * generated at keypad init
1647 	 */
1648 	if (lcd.enabled) {
1649 		lcd_init();
1650 		if (!lcd.charlcd || charlcd_register(lcd.charlcd))
1651 			goto err_unreg_device;
1652 	}
1653 
1654 	if (keypad.enabled) {
1655 		keypad_init();
1656 		if (misc_register(&keypad_dev))
1657 			goto err_lcd_unreg;
1658 	}
1659 	return;
1660 
1661 err_lcd_unreg:
1662 	if (scan_timer.function)
1663 		del_timer_sync(&scan_timer);
1664 	if (lcd.enabled)
1665 		charlcd_unregister(lcd.charlcd);
1666 err_unreg_device:
1667 	kfree(lcd.charlcd);
1668 	lcd.charlcd = NULL;
1669 	parport_unregister_device(pprt);
1670 	pprt = NULL;
1671 }
1672 
1673 static void panel_detach(struct parport *port)
1674 {
1675 	if (port->number != parport)
1676 		return;
1677 
1678 	if (!pprt) {
1679 		pr_err("%s: port->number=%d parport=%d, nothing to unregister.\n",
1680 		       __func__, port->number, parport);
1681 		return;
1682 	}
1683 	if (scan_timer.function)
1684 		del_timer_sync(&scan_timer);
1685 
1686 	if (keypad.enabled) {
1687 		misc_deregister(&keypad_dev);
1688 		keypad_initialized = 0;
1689 	}
1690 
1691 	if (lcd.enabled) {
1692 		charlcd_unregister(lcd.charlcd);
1693 		lcd.initialized = false;
1694 		kfree(lcd.charlcd->drvdata);
1695 		kfree(lcd.charlcd);
1696 		lcd.charlcd = NULL;
1697 	}
1698 
1699 	/* TODO: free all input signals */
1700 	parport_release(pprt);
1701 	parport_unregister_device(pprt);
1702 	pprt = NULL;
1703 }
1704 
1705 static struct parport_driver panel_driver = {
1706 	.name = "panel",
1707 	.match_port = panel_attach,
1708 	.detach = panel_detach,
1709 };
1710 module_parport_driver(panel_driver);
1711 
1712 MODULE_AUTHOR("Willy Tarreau");
1713 MODULE_LICENSE("GPL");
1714