xref: /openbmc/linux/drivers/input/misc/hp_sdc_rtc.c (revision 0d7aeb68)
1 /*
2  * HP i8042 SDC + MSM-58321 BBRTC driver.
3  *
4  * Copyright (c) 2001 Brian S. Julin
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions, and the following disclaimer,
12  *    without modification.
13  * 2. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * Alternatively, this software may be distributed under the terms of the
17  * GNU General Public License ("GPL").
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
23  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  *
29  * References:
30  * System Device Controller Microprocessor Firmware Theory of Operation
31  *      for Part Number 1820-4784 Revision B.  Dwg No. A-1820-4784-2
32  * efirtc.c by Stephane Eranian/Hewlett Packard
33  *
34  */
35 
36 #include <linux/hp_sdc.h>
37 #include <linux/errno.h>
38 #include <linux/types.h>
39 #include <linux/init.h>
40 #include <linux/module.h>
41 #include <linux/time.h>
42 #include <linux/miscdevice.h>
43 #include <linux/proc_fs.h>
44 #include <linux/seq_file.h>
45 #include <linux/poll.h>
46 #include <linux/rtc.h>
47 #include <linux/mutex.h>
48 #include <linux/semaphore.h>
49 
50 MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
51 MODULE_DESCRIPTION("HP i8042 SDC + MSM-58321 RTC Driver");
52 MODULE_LICENSE("Dual BSD/GPL");
53 
54 #define RTC_VERSION "1.10d"
55 
56 static unsigned long epoch = 2000;
57 
58 static struct semaphore i8042tregs;
59 
60 static void hp_sdc_rtc_isr (int irq, void *dev_id,
61 			    uint8_t status, uint8_t data)
62 {
63 	return;
64 }
65 
66 static int hp_sdc_rtc_do_read_bbrtc (struct rtc_time *rtctm)
67 {
68 	struct semaphore tsem;
69 	hp_sdc_transaction t;
70 	uint8_t tseq[91];
71 	int i;
72 
73 	i = 0;
74 	while (i < 91) {
75 		tseq[i++] = HP_SDC_ACT_DATAREG |
76 			HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN;
77 		tseq[i++] = 0x01;			/* write i8042[0x70] */
78 	  	tseq[i]   = i / 7;			/* BBRTC reg address */
79 		i++;
80 		tseq[i++] = HP_SDC_CMD_DO_RTCR;		/* Trigger command   */
81 		tseq[i++] = 2;		/* expect 1 stat/dat pair back.   */
82 		i++; i++;               /* buffer for stat/dat pair       */
83 	}
84 	tseq[84] |= HP_SDC_ACT_SEMAPHORE;
85 	t.endidx =		91;
86 	t.seq =			tseq;
87 	t.act.semaphore =	&tsem;
88 	sema_init(&tsem, 0);
89 
90 	if (hp_sdc_enqueue_transaction(&t)) return -1;
91 
92 	/* Put ourselves to sleep for results. */
93 	if (WARN_ON(down_interruptible(&tsem)))
94 		return -1;
95 
96 	/* Check for nonpresence of BBRTC */
97 	if (!((tseq[83] | tseq[90] | tseq[69] | tseq[76] |
98 	       tseq[55] | tseq[62] | tseq[34] | tseq[41] |
99 	       tseq[20] | tseq[27] | tseq[6]  | tseq[13]) & 0x0f))
100 		return -1;
101 
102 	memset(rtctm, 0, sizeof(struct rtc_time));
103 	rtctm->tm_year = (tseq[83] & 0x0f) + (tseq[90] & 0x0f) * 10;
104 	rtctm->tm_mon  = (tseq[69] & 0x0f) + (tseq[76] & 0x0f) * 10;
105 	rtctm->tm_mday = (tseq[55] & 0x0f) + (tseq[62] & 0x0f) * 10;
106 	rtctm->tm_wday = (tseq[48] & 0x0f);
107 	rtctm->tm_hour = (tseq[34] & 0x0f) + (tseq[41] & 0x0f) * 10;
108 	rtctm->tm_min  = (tseq[20] & 0x0f) + (tseq[27] & 0x0f) * 10;
109 	rtctm->tm_sec  = (tseq[6]  & 0x0f) + (tseq[13] & 0x0f) * 10;
110 
111 	return 0;
112 }
113 
114 static int hp_sdc_rtc_read_bbrtc (struct rtc_time *rtctm)
115 {
116 	struct rtc_time tm, tm_last;
117 	int i = 0;
118 
119 	/* MSM-58321 has no read latch, so must read twice and compare. */
120 
121 	if (hp_sdc_rtc_do_read_bbrtc(&tm_last)) return -1;
122 	if (hp_sdc_rtc_do_read_bbrtc(&tm)) return -1;
123 
124 	while (memcmp(&tm, &tm_last, sizeof(struct rtc_time))) {
125 		if (i++ > 4) return -1;
126 		memcpy(&tm_last, &tm, sizeof(struct rtc_time));
127 		if (hp_sdc_rtc_do_read_bbrtc(&tm)) return -1;
128 	}
129 
130 	memcpy(rtctm, &tm, sizeof(struct rtc_time));
131 
132 	return 0;
133 }
134 
135 
136 static int64_t hp_sdc_rtc_read_i8042timer (uint8_t loadcmd, int numreg)
137 {
138 	hp_sdc_transaction t;
139 	uint8_t tseq[26] = {
140 		HP_SDC_ACT_PRECMD | HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
141 		0,
142 		HP_SDC_CMD_READ_T1, 2, 0, 0,
143 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
144 		HP_SDC_CMD_READ_T2, 2, 0, 0,
145 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
146 		HP_SDC_CMD_READ_T3, 2, 0, 0,
147 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
148 		HP_SDC_CMD_READ_T4, 2, 0, 0,
149 		HP_SDC_ACT_POSTCMD | HP_SDC_ACT_DATAIN,
150 		HP_SDC_CMD_READ_T5, 2, 0, 0
151 	};
152 
153 	t.endidx = numreg * 5;
154 
155 	tseq[1] = loadcmd;
156 	tseq[t.endidx - 4] |= HP_SDC_ACT_SEMAPHORE; /* numreg assumed > 1 */
157 
158 	t.seq =			tseq;
159 	t.act.semaphore =	&i8042tregs;
160 
161 	/* Sleep if output regs in use. */
162 	if (WARN_ON(down_interruptible(&i8042tregs)))
163 		return -1;
164 
165 	if (hp_sdc_enqueue_transaction(&t)) {
166 		up(&i8042tregs);
167 		return -1;
168 	}
169 
170 	/* Sleep until results come back. */
171 	if (WARN_ON(down_interruptible(&i8042tregs)))
172 		return -1;
173 
174 	up(&i8042tregs);
175 
176 	return (tseq[5] |
177 		((uint64_t)(tseq[10]) << 8)  | ((uint64_t)(tseq[15]) << 16) |
178 		((uint64_t)(tseq[20]) << 24) | ((uint64_t)(tseq[25]) << 32));
179 }
180 
181 
182 /* Read the i8042 real-time clock */
183 static inline int hp_sdc_rtc_read_rt(struct timespec64 *res) {
184 	int64_t raw;
185 	uint32_t tenms;
186 	unsigned int days;
187 
188 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_RT, 5);
189 	if (raw < 0) return -1;
190 
191 	tenms = (uint32_t)raw & 0xffffff;
192 	days  = (unsigned int)(raw >> 24) & 0xffff;
193 
194 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
195 	res->tv_sec =  (tenms / 100) + (time64_t)days * 86400;
196 
197 	return 0;
198 }
199 
200 
201 /* Read the i8042 fast handshake timer */
202 static inline int hp_sdc_rtc_read_fhs(struct timespec64 *res) {
203 	int64_t raw;
204 	unsigned int tenms;
205 
206 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_FHS, 2);
207 	if (raw < 0) return -1;
208 
209 	tenms = (unsigned int)raw & 0xffff;
210 
211 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
212 	res->tv_sec  = (time64_t)(tenms / 100);
213 
214 	return 0;
215 }
216 
217 
218 /* Read the i8042 match timer (a.k.a. alarm) */
219 static inline int hp_sdc_rtc_read_mt(struct timespec64 *res) {
220 	int64_t raw;
221 	uint32_t tenms;
222 
223 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_MT, 3);
224 	if (raw < 0) return -1;
225 
226 	tenms = (uint32_t)raw & 0xffffff;
227 
228 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
229 	res->tv_sec  = (time64_t)(tenms / 100);
230 
231 	return 0;
232 }
233 
234 
235 /* Read the i8042 delay timer */
236 static inline int hp_sdc_rtc_read_dt(struct timespec64 *res) {
237 	int64_t raw;
238 	uint32_t tenms;
239 
240 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_DT, 3);
241 	if (raw < 0) return -1;
242 
243 	tenms = (uint32_t)raw & 0xffffff;
244 
245 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
246 	res->tv_sec  = (time64_t)(tenms / 100);
247 
248 	return 0;
249 }
250 
251 
252 /* Read the i8042 cycle timer (a.k.a. periodic) */
253 static inline int hp_sdc_rtc_read_ct(struct timespec64 *res) {
254 	int64_t raw;
255 	uint32_t tenms;
256 
257 	raw = hp_sdc_rtc_read_i8042timer(HP_SDC_CMD_LOAD_CT, 3);
258 	if (raw < 0) return -1;
259 
260 	tenms = (uint32_t)raw & 0xffffff;
261 
262 	res->tv_nsec = (long)(tenms % 100) * 10000 * 1000;
263 	res->tv_sec  = (time64_t)(tenms / 100);
264 
265 	return 0;
266 }
267 
268 static int __maybe_unused hp_sdc_rtc_proc_show(struct seq_file *m, void *v)
269 {
270 #define YN(bit) ("no")
271 #define NY(bit) ("yes")
272         struct rtc_time tm;
273 	struct timespec64 tv;
274 
275 	memset(&tm, 0, sizeof(struct rtc_time));
276 
277 	if (hp_sdc_rtc_read_bbrtc(&tm)) {
278 		seq_puts(m, "BBRTC\t\t: READ FAILED!\n");
279 	} else {
280 		seq_printf(m,
281 			     "rtc_time\t: %ptRt\n"
282 			     "rtc_date\t: %ptRd\n"
283 			     "rtc_epoch\t: %04lu\n",
284 			     &tm, &tm, epoch);
285 	}
286 
287 	if (hp_sdc_rtc_read_rt(&tv)) {
288 		seq_puts(m, "i8042 rtc\t: READ FAILED!\n");
289 	} else {
290 		seq_printf(m, "i8042 rtc\t: %lld.%02ld seconds\n",
291 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
292 	}
293 
294 	if (hp_sdc_rtc_read_fhs(&tv)) {
295 		seq_puts(m, "handshake\t: READ FAILED!\n");
296 	} else {
297 		seq_printf(m, "handshake\t: %lld.%02ld seconds\n",
298 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
299 	}
300 
301 	if (hp_sdc_rtc_read_mt(&tv)) {
302 		seq_puts(m, "alarm\t\t: READ FAILED!\n");
303 	} else {
304 		seq_printf(m, "alarm\t\t: %lld.%02ld seconds\n",
305 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
306 	}
307 
308 	if (hp_sdc_rtc_read_dt(&tv)) {
309 		seq_puts(m, "delay\t\t: READ FAILED!\n");
310 	} else {
311 		seq_printf(m, "delay\t\t: %lld.%02ld seconds\n",
312 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
313 	}
314 
315 	if (hp_sdc_rtc_read_ct(&tv)) {
316 		seq_puts(m, "periodic\t: READ FAILED!\n");
317 	} else {
318 		seq_printf(m, "periodic\t: %lld.%02ld seconds\n",
319 			     (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
320 	}
321 
322         seq_printf(m,
323                      "DST_enable\t: %s\n"
324                      "BCD\t\t: %s\n"
325                      "24hr\t\t: %s\n"
326                      "square_wave\t: %s\n"
327                      "alarm_IRQ\t: %s\n"
328                      "update_IRQ\t: %s\n"
329                      "periodic_IRQ\t: %s\n"
330 		     "periodic_freq\t: %ld\n"
331                      "batt_status\t: %s\n",
332                      YN(RTC_DST_EN),
333                      NY(RTC_DM_BINARY),
334                      YN(RTC_24H),
335                      YN(RTC_SQWE),
336                      YN(RTC_AIE),
337                      YN(RTC_UIE),
338                      YN(RTC_PIE),
339                      1UL,
340                      1 ? "okay" : "dead");
341 
342         return 0;
343 #undef YN
344 #undef NY
345 }
346 
347 static int __init hp_sdc_rtc_init(void)
348 {
349 	int ret;
350 
351 #ifdef __mc68000__
352 	if (!MACH_IS_HP300)
353 		return -ENODEV;
354 #endif
355 
356 	sema_init(&i8042tregs, 1);
357 
358 	if ((ret = hp_sdc_request_timer_irq(&hp_sdc_rtc_isr)))
359 		return ret;
360 
361         proc_create_single("driver/rtc", 0, NULL, hp_sdc_rtc_proc_show);
362 
363 	printk(KERN_INFO "HP i8042 SDC + MSM-58321 RTC support loaded "
364 			 "(RTC v " RTC_VERSION ")\n");
365 
366 	return 0;
367 }
368 
369 static void __exit hp_sdc_rtc_exit(void)
370 {
371 	remove_proc_entry ("driver/rtc", NULL);
372 	hp_sdc_release_timer_irq(hp_sdc_rtc_isr);
373         printk(KERN_INFO "HP i8042 SDC + MSM-58321 RTC support unloaded\n");
374 }
375 
376 module_init(hp_sdc_rtc_init);
377 module_exit(hp_sdc_rtc_exit);
378