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
50MODULE_AUTHOR("Brian S. Julin <bri@calyx.com>");
51MODULE_DESCRIPTION("HP i8042 SDC + MSM-58321 RTC Driver");
52MODULE_LICENSE("Dual BSD/GPL");
53
54#define RTC_VERSION "1.10d"
55
56static unsigned long epoch = 2000;
57
58static struct semaphore i8042tregs;
59
60static void hp_sdc_rtc_isr (int irq, void *dev_id,
61			    uint8_t status, uint8_t data)
62{
63	return;
64}
65
66static 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
114static 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
136static 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 */
183static 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 */
202static 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) */
219static 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 */
236static 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) */
253static 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
268static 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
347static 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
369static 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
376module_init(hp_sdc_rtc_init);
377module_exit(hp_sdc_rtc_exit);
378