aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/platforms/powermac/time.c
blob: 1810e4226e5615543999e7242a8c467991707907 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
/*
 * Support for periodic interrupts (100 per second) and for getting
 * the current time from the RTC on Power Macintoshes.
 *
 * We use the decrementer register for our periodic interrupts.
 *
 * Paul Mackerras	August 1996.
 * Copyright (C) 1996 Paul Mackerras.
 * Copyright (C) 2003-2005 Benjamin Herrenschmidt.
 *
 */
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/adb.h>
#include <linux/cuda.h>
#include <linux/pmu.h>
#include <linux/interrupt.h>
#include <linux/hardirq.h>
#include <linux/rtc.h>

#include <asm/sections.h>
#include <asm/prom.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/machdep.h>
#include <asm/time.h>
#include <asm/nvram.h>
#include <asm/smu.h>

#undef DEBUG

#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif

/* Apparently the RTC stores seconds since 1 Jan 1904 */
#define RTC_OFFSET	2082844800

/*
 * Calibrate the decrementer frequency with the VIA timer 1.
 */
#define VIA_TIMER_FREQ_6	4700000	/* time 1 frequency * 6 */

/* VIA registers */
#define RS		0x200		/* skip between registers */
#define T1CL		(4*RS)		/* Timer 1 ctr/latch (low 8 bits) */
#define T1CH		(5*RS)		/* Timer 1 counter (high 8 bits) */
#define T1LL		(6*RS)		/* Timer 1 latch (low 8 bits) */
#define T1LH		(7*RS)		/* Timer 1 latch (high 8 bits) */
#define ACR		(11*RS)		/* Auxiliary control register */
#define IFR		(13*RS)		/* Interrupt flag register */

/* Bits in ACR */
#define T1MODE		0xc0		/* Timer 1 mode */
#define T1MODE_CONT	0x40		/*  continuous interrupts */

/* Bits in IFR and IER */
#define T1_INT		0x40		/* Timer 1 interrupt */

long __init pmac_time_init(void)
{
	s32 delta = 0;
#ifdef CONFIG_NVRAM
	int dst;
	
	delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
	delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
	delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
	if (delta & 0x00800000UL)
		delta |= 0xFF000000UL;
	dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
	printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
		dst ? "on" : "off");
#endif
	return delta;
}

#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
static void to_rtc_time(unsigned long now, struct rtc_time *tm)
{
	to_tm(now, tm);
	tm->tm_year -= 1900;
	tm->tm_mon -= 1;
}
#endif

#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU) || \
    defined(CONFIG_PMAC_SMU)
static unsigned long from_rtc_time(struct rtc_time *tm)
{
	return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
		      tm->tm_hour, tm->tm_min, tm->tm_sec);
}
#endif

#ifdef CONFIG_ADB_CUDA
static unsigned long cuda_get_time(void)
{
	struct adb_request req;
	unsigned int now;

	if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
		return 0;
	while (!req.complete)
		cuda_poll();
	if (req.reply_len != 7)
		printk(KERN_ERR "cuda_get_time: got %d byte reply\n",
		       req.reply_len);
	now = (req.reply[3] << 24) + (req.reply[4] << 16)
		+ (req.reply[5] << 8) + req.reply[6];
	return ((unsigned long)now) - RTC_OFFSET;
}

#define cuda_get_rtc_time(tm)	to_rtc_time(cuda_get_time(), (tm))

static int cuda_set_rtc_time(struct rtc_time *tm)
{
	unsigned int nowtime;
	struct adb_request req;

	nowtime = from_rtc_time(tm) + RTC_OFFSET;
	if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
			 nowtime >> 24, nowtime >> 16, nowtime >> 8,
			 nowtime) < 0)
		return -ENXIO;
	while (!req.complete)
		cuda_poll();
	if ((req.reply_len != 3) && (req.reply_len != 7))
		printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n",
		       req.reply_len);
	return 0;
}

#else
#define cuda_get_time()		0
#define cuda_get_rtc_time(tm)
#define cuda_set_rtc_time(tm)	0
#endif

#ifdef CONFIG_ADB_PMU
static unsigned long pmu_get_time(void)
{
	struct adb_request req;
	unsigned int now;

	if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
		return 0;
	pmu_wait_complete(&req);
	if (req.reply_len != 4)
		printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n",
		       req.reply_len);
	now = (req.reply[0] << 24) + (req.reply[1] << 16)
		+ (req.reply[2] << 8) + req.reply[3];
	return ((unsigned long)now) - RTC_OFFSET;
}

#define pmu_get_rtc_time(tm)	to_rtc_time(pmu_get_time(), (tm))

static int pmu_set_rtc_time(struct rtc_time *tm)
{
	unsigned int nowtime;
	struct adb_request req;

	nowtime = from_rtc_time(tm) + RTC_OFFSET;
	if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24,
			nowtime >> 16, nowtime >> 8, nowtime) < 0)
		return -ENXIO;
	pmu_wait_complete(&req);
	if (req.reply_len != 0)
		printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n",
		       req.reply_len);
	return 0;
}

#else
#define pmu_get_time()		0
#define pmu_get_rtc_time(tm)
#define pmu_set_rtc_time(tm)	0
#endif

#ifdef CONFIG_PMAC_SMU
static unsigned long smu_get_time(void)
{
	struct rtc_time tm;

	if (smu_get_rtc_time(&tm, 1))
		return 0;
	return from_rtc_time(&tm);
}

#else
#define smu_get_time()			0
#define smu_get_rtc_time(tm, spin)
#define smu_set_rtc_time(tm, spin)	0
#endif

/* Can't be __init, it's called when suspending and resuming */
unsigned long pmac_get_boot_time(void)
{
	/* Get the time from the RTC, used only at boot time */
	switch (sys_ctrler) {
	case SYS_CTRLER_CUDA:
		return cuda_get_time();
	case SYS_CTRLER_PMU:
		return pmu_get_time();
	case SYS_CTRLER_SMU:
		return smu_get_time();
	default:
		return 0;
	}
}

void pmac_get_rtc_time(struct rtc_time *tm)
{
	/* Get the time from the RTC, used only at boot time */
	switch (sys_ctrler) {
	case SYS_CTRLER_CUDA:
		cuda_get_rtc_time(tm);
		break;
	case SYS_CTRLER_PMU:
		pmu_get_rtc_time(tm);
		break;
	case SYS_CTRLER_SMU:
		smu_get_rtc_time(tm, 1);
		break;
	default:
		;
	}
}

int pmac_set_rtc_time(struct rtc_time *tm)
{
	switch (sys_ctrler) {
	case SYS_CTRLER_CUDA:
		return cuda_set_rtc_time(tm);
	case SYS_CTRLER_PMU:
		return pmu_set_rtc_time(tm);
	case SYS_CTRLER_SMU:
		return smu_set_rtc_time(tm, 1);
	default:
		return -ENODEV;
	}
}

#ifdef CONFIG_PPC32
/*
 * Calibrate the decrementer register using VIA timer 1.
 * This is used both on powermacs and CHRP machines.
 */
int __init via_calibrate_decr(void)
{
	struct device_node *vias;
	volatile unsigned char __iomem *via;
	int count = VIA_TIMER_FREQ_6 / 100;
	unsigned int dstart, dend;
	struct resource rsrc;

	vias = of_find_node_by_name(NULL, "via-cuda");
	if (vias == NULL)
		vias = of_find_node_by_name(NULL, "via-pmu");
	if (vias == NULL)
		vias = of_find_node_by_name(NULL, "via");
	if (vias == NULL || of_address_to_resource(vias, 0, &rsrc)) {
	        of_node_put(vias);
		return 0;
	}
	of_node_put(vias);
	via = ioremap(rsrc.start, rsrc.end - rsrc.start + 1);
	if (via == NULL) {
		printk(KERN_ERR "Failed to map VIA for timer calibration !\n");
		return 0;
	}

	/* set timer 1 for continuous interrupts */
	out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
	/* set the counter to a small value */
	out_8(&via[T1CH], 2);
	/* set the latch to `count' */
	out_8(&via[T1LL], count);
	out_8(&via[T1LH], count >> 8);
	/* wait until it hits 0 */
	while ((in_8(&via[IFR]) & T1_INT) == 0)
		;
	dstart = get_dec();
	/* clear the interrupt & wait until it hits 0 again */
	in_8(&via[T1CL]);
	while ((in_8(&via[IFR]) & T1_INT) == 0)
		;
	dend = get_dec();

	ppc_tb_freq = (dstart - dend) * 100 / 6;

	iounmap(via);

	return 1;
}
#endif

/*
 * Query the OF and get the decr frequency.
 */
void __init pmac_calibrate_decr(void)
{
	generic_calibrate_decr();

#ifdef CONFIG_PPC32
	/* We assume MacRISC2 machines have correct device-tree
	 * calibration. That's better since the VIA itself seems
	 * to be slightly off. --BenH
	 */
	if (!machine_is_compatible("MacRISC2") &&
	    !machine_is_compatible("MacRISC3") &&
	    !machine_is_compatible("MacRISC4"))
		if (via_calibrate_decr())
			return;

	/* Special case: QuickSilver G4s seem to have a badly calibrated
	 * timebase-frequency in OF, VIA is much better on these. We should
	 * probably implement calibration based on the KL timer on these
	 * machines anyway... -BenH
	 */
	if (machine_is_compatible("PowerMac3,5"))
		if (via_calibrate_decr())
			return;
#endif
}