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(sem: &tsem, val: 0);
89
90 if (hp_sdc_enqueue_transaction(this: &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(rtctm: &tm_last)) return -1;
122 if (hp_sdc_rtc_do_read_bbrtc(rtctm: &tm)) return -1;
123
124 while (memcmp(p: &tm, q: &tm_last, size: 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(rtctm: &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(this: &t)) {
166 up(sem: &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(sem: &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, numreg: 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, numreg: 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, numreg: 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, numreg: 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, numreg: 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(rtctm: &tm)) {
278 seq_puts(m, s: "BBRTC\t\t: READ FAILED!\n");
279 } else {
280 seq_printf(m,
281 fmt: "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(res: &tv)) {
288 seq_puts(m, s: "i8042 rtc\t: READ FAILED!\n");
289 } else {
290 seq_printf(m, fmt: "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(res: &tv)) {
295 seq_puts(m, s: "handshake\t: READ FAILED!\n");
296 } else {
297 seq_printf(m, fmt: "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(res: &tv)) {
302 seq_puts(m, s: "alarm\t\t: READ FAILED!\n");
303 } else {
304 seq_printf(m, fmt: "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(res: &tv)) {
309 seq_puts(m, s: "delay\t\t: READ FAILED!\n");
310 } else {
311 seq_printf(m, fmt: "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(res: &tv)) {
316 seq_puts(m, s: "periodic\t: READ FAILED!\n");
317 } else {
318 seq_printf(m, fmt: "periodic\t: %lld.%02ld seconds\n",
319 (s64)tv.tv_sec, (long)tv.tv_nsec/1000000L);
320 }
321
322 seq_printf(m,
323 fmt: "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(sem: &i8042tregs, val: 1);
357
358 if ((ret = hp_sdc_request_timer_irq(callback: &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(callback: 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

source code of linux/drivers/input/misc/hp_sdc_rtc.c