1 /*
2 * Support for periodic interrupts (100 per second) and for getting
3 * the current time from the RTC on Power Macintoshes.
4 *
5 * We use the decrementer register for our periodic interrupts.
6 *
7 * Paul Mackerras August 1996.
8 * Copyright (C) 1996 Paul Mackerras.
9 * Copyright (C) 2003-2005 Benjamin Herrenschmidt.
10 *
11 */
12 #include <linux/errno.h>
13 #include <linux/sched.h>
14 #include <linux/kernel.h>
15 #include <linux/param.h>
16 #include <linux/string.h>
17 #include <linux/mm.h>
18 #include <linux/init.h>
19 #include <linux/time.h>
20 #include <linux/adb.h>
21 #include <linux/cuda.h>
22 #include <linux/pmu.h>
23 #include <linux/interrupt.h>
24 #include <linux/hardirq.h>
25 #include <linux/rtc.h>
26
27 #include <asm/sections.h>
28 #include <asm/prom.h>
29 #include <asm/system.h>
30 #include <asm/io.h>
31 #include <asm/pgtable.h>
32 #include <asm/machdep.h>
33 #include <asm/time.h>
34 #include <asm/nvram.h>
35 #include <asm/smu.h>
36
37 #undef DEBUG
38
39 #ifdef DEBUG
40 #define DBG(x...) printk(x)
41 #else
42 #define DBG(x...)
43 #endif
44
45 /* Apparently the RTC stores seconds since 1 Jan 1904 */
46 #define RTC_OFFSET 2082844800
47
48 /*
49 * Calibrate the decrementer frequency with the VIA timer 1.
50 */
51 #define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */
52
53 /* VIA registers */
54 #define RS 0x200 /* skip between registers */
55 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
56 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
57 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
58 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
59 #define ACR (11*RS) /* Auxiliary control register */
60 #define IFR (13*RS) /* Interrupt flag register */
61
62 /* Bits in ACR */
63 #define T1MODE 0xc0 /* Timer 1 mode */
64 #define T1MODE_CONT 0x40 /* continuous interrupts */
65
66 /* Bits in IFR and IER */
67 #define T1_INT 0x40 /* Timer 1 interrupt */
68
pmac_time_init(void)69 long __init pmac_time_init(void)
70 {
71 s32 delta = 0;
72 #ifdef CONFIG_NVRAM
73 int dst;
74
75 delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
76 delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
77 delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
78 if (delta & 0x00800000UL)
79 delta |= 0xFF000000UL;
80 dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
81 printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
82 dst ? "on" : "off");
83 #endif
84 return delta;
85 }
86
87 #if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
to_rtc_time(unsigned long now,struct rtc_time * tm)88 static void to_rtc_time(unsigned long now, struct rtc_time *tm)
89 {
90 to_tm(now, tm);
91 tm->tm_year -= 1900;
92 tm->tm_mon -= 1;
93 }
94 #endif
95
96 #if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) || \
97 defined(CONFIG_PMAC_SMU)
from_rtc_time(struct rtc_time * tm)98 static unsigned long from_rtc_time(struct rtc_time *tm)
99 {
100 return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
101 tm->tm_hour, tm->tm_min, tm->tm_sec);
102 }
103 #endif
104
105 #ifdef CONFIG_ADB_CUDA
cuda_get_time(void)106 static unsigned long cuda_get_time(void)
107 {
108 struct adb_request req;
109 unsigned int now;
110
111 if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
112 return 0;
113 while (!req.complete)
114 cuda_poll();
115 if (req.reply_len != 7)
116 printk(KERN_ERR "cuda_get_time: got %d byte reply\n",
117 req.reply_len);
118 now = (req.reply[3] << 24) + (req.reply[4] << 16)
119 + (req.reply[5] << 8) + req.reply[6];
120 return ((unsigned long)now) - RTC_OFFSET;
121 }
122
123 #define cuda_get_rtc_time(tm) to_rtc_time(cuda_get_time(), (tm))
124
cuda_set_rtc_time(struct rtc_time * tm)125 static int cuda_set_rtc_time(struct rtc_time *tm)
126 {
127 unsigned int nowtime;
128 struct adb_request req;
129
130 nowtime = from_rtc_time(tm) + RTC_OFFSET;
131 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
132 nowtime >> 24, nowtime >> 16, nowtime >> 8,
133 nowtime) < 0)
134 return -ENXIO;
135 while (!req.complete)
136 cuda_poll();
137 if ((req.reply_len != 3) && (req.reply_len != 7))
138 printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n",
139 req.reply_len);
140 return 0;
141 }
142
143 #else
144 #define cuda_get_time() 0
145 #define cuda_get_rtc_time(tm)
146 #define cuda_set_rtc_time(tm) 0
147 #endif
148
149 #ifdef CONFIG_ADB_PMU
pmu_get_time(void)150 static unsigned long pmu_get_time(void)
151 {
152 struct adb_request req;
153 unsigned int now;
154
155 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
156 return 0;
157 pmu_wait_complete(&req);
158 if (req.reply_len != 4)
159 printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n",
160 req.reply_len);
161 now = (req.reply[0] << 24) + (req.reply[1] << 16)
162 + (req.reply[2] << 8) + req.reply[3];
163 return ((unsigned long)now) - RTC_OFFSET;
164 }
165
166 #define pmu_get_rtc_time(tm) to_rtc_time(pmu_get_time(), (tm))
167
pmu_set_rtc_time(struct rtc_time * tm)168 static int pmu_set_rtc_time(struct rtc_time *tm)
169 {
170 unsigned int nowtime;
171 struct adb_request req;
172
173 nowtime = from_rtc_time(tm) + RTC_OFFSET;
174 if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24,
175 nowtime >> 16, nowtime >> 8, nowtime) < 0)
176 return -ENXIO;
177 pmu_wait_complete(&req);
178 if (req.reply_len != 0)
179 printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n",
180 req.reply_len);
181 return 0;
182 }
183
184 #else
185 #define pmu_get_time() 0
186 #define pmu_get_rtc_time(tm)
187 #define pmu_set_rtc_time(tm) 0
188 #endif
189
190 #ifdef CONFIG_PMAC_SMU
smu_get_time(void)191 static unsigned long smu_get_time(void)
192 {
193 struct rtc_time tm;
194
195 if (smu_get_rtc_time(&tm, 1))
196 return 0;
197 return from_rtc_time(&tm);
198 }
199
200 #else
201 #define smu_get_time() 0
202 #define smu_get_rtc_time(tm, spin)
203 #define smu_set_rtc_time(tm, spin) 0
204 #endif
205
206 /* Can't be __init, it's called when suspending and resuming */
pmac_get_boot_time(void)207 unsigned long pmac_get_boot_time(void)
208 {
209 /* Get the time from the RTC, used only at boot time */
210 switch (sys_ctrler) {
211 case SYS_CTRLER_CUDA:
212 return cuda_get_time();
213 case SYS_CTRLER_PMU:
214 return pmu_get_time();
215 case SYS_CTRLER_SMU:
216 return smu_get_time();
217 default:
218 return 0;
219 }
220 }
221
pmac_get_rtc_time(struct rtc_time * tm)222 void pmac_get_rtc_time(struct rtc_time *tm)
223 {
224 /* Get the time from the RTC, used only at boot time */
225 switch (sys_ctrler) {
226 case SYS_CTRLER_CUDA:
227 cuda_get_rtc_time(tm);
228 break;
229 case SYS_CTRLER_PMU:
230 pmu_get_rtc_time(tm);
231 break;
232 case SYS_CTRLER_SMU:
233 smu_get_rtc_time(tm, 1);
234 break;
235 default:
236 ;
237 }
238 }
239
pmac_set_rtc_time(struct rtc_time * tm)240 int pmac_set_rtc_time(struct rtc_time *tm)
241 {
242 switch (sys_ctrler) {
243 case SYS_CTRLER_CUDA:
244 return cuda_set_rtc_time(tm);
245 case SYS_CTRLER_PMU:
246 return pmu_set_rtc_time(tm);
247 case SYS_CTRLER_SMU:
248 return smu_set_rtc_time(tm, 1);
249 default:
250 return -ENODEV;
251 }
252 }
253
254 #ifdef CONFIG_PPC32
255 /*
256 * Calibrate the decrementer register using VIA timer 1.
257 * This is used both on powermacs and CHRP machines.
258 */
via_calibrate_decr(void)259 int __init via_calibrate_decr(void)
260 {
261 struct device_node *vias;
262 volatile unsigned char __iomem *via;
263 int count = VIA_TIMER_FREQ_6 / 100;
264 unsigned int dstart, dend;
265 struct resource rsrc;
266
267 vias = of_find_node_by_name(NULL, "via-cuda");
268 if (vias == NULL)
269 vias = of_find_node_by_name(NULL, "via-pmu");
270 if (vias == NULL)
271 vias = of_find_node_by_name(NULL, "via");
272 if (vias == NULL || of_address_to_resource(vias, 0, &rsrc)) {
273 of_node_put(vias);
274 return 0;
275 }
276 of_node_put(vias);
277 via = ioremap(rsrc.start, rsrc.end - rsrc.start + 1);
278 if (via == NULL) {
279 printk(KERN_ERR "Failed to map VIA for timer calibration !\n");
280 return 0;
281 }
282
283 /* set timer 1 for continuous interrupts */
284 out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
285 /* set the counter to a small value */
286 out_8(&via[T1CH], 2);
287 /* set the latch to `count' */
288 out_8(&via[T1LL], count);
289 out_8(&via[T1LH], count >> 8);
290 /* wait until it hits 0 */
291 while ((in_8(&via[IFR]) & T1_INT) == 0)
292 ;
293 dstart = get_dec();
294 /* clear the interrupt & wait until it hits 0 again */
295 in_8(&via[T1CL]);
296 while ((in_8(&via[IFR]) & T1_INT) == 0)
297 ;
298 dend = get_dec();
299
300 ppc_tb_freq = (dstart - dend) * 100 / 6;
301
302 iounmap(via);
303
304 return 1;
305 }
306 #endif
307
308 /*
309 * Query the OF and get the decr frequency.
310 */
pmac_calibrate_decr(void)311 void __init pmac_calibrate_decr(void)
312 {
313 generic_calibrate_decr();
314
315 #ifdef CONFIG_PPC32
316 /* We assume MacRISC2 machines have correct device-tree
317 * calibration. That's better since the VIA itself seems
318 * to be slightly off. --BenH
319 */
320 if (!machine_is_compatible("MacRISC2") &&
321 !machine_is_compatible("MacRISC3") &&
322 !machine_is_compatible("MacRISC4"))
323 if (via_calibrate_decr())
324 return;
325
326 /* Special case: QuickSilver G4s seem to have a badly calibrated
327 * timebase-frequency in OF, VIA is much better on these. We should
328 * probably implement calibration based on the KL timer on these
329 * machines anyway... -BenH
330 */
331 if (machine_is_compatible("PowerMac3,5"))
332 if (via_calibrate_decr())
333 return;
334 #endif
335 }
336