xref: /openbmc/linux/drivers/sbus/char/envctrl.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /* $Id: envctrl.c,v 1.25 2002/01/15 09:01:26 davem Exp $
2  * envctrl.c: Temperature and Fan monitoring on Machines providing it.
3  *
4  * Copyright (C) 1998  Eddie C. Dost  (ecd@skynet.be)
5  * Copyright (C) 2000  Vinh Truong    (vinh.truong@eng.sun.com)
6  * VT - The implementation is to support Sun Microelectronics (SME) platform
7  *      environment monitoring.  SME platforms use pcf8584 as the i2c bus
8  *      controller to access pcf8591 (8-bit A/D and D/A converter) and
9  *      pcf8571 (256 x 8-bit static low-voltage RAM with I2C-bus interface).
10  *      At board level, it follows SME Firmware I2C Specification. Reference:
11  * 	http://www-eu2.semiconductors.com/pip/PCF8584P
12  * 	http://www-eu2.semiconductors.com/pip/PCF8574AP
13  * 	http://www-eu2.semiconductors.com/pip/PCF8591P
14  *
15  * EB - Added support for CP1500 Global Address and PS/Voltage monitoring.
16  * 		Eric Brower <ebrower@usa.net>
17  *
18  * DB - Audit every copy_to_user in envctrl_read.
19  *              Daniele Bellucci <bellucda@tiscali.it>
20  */
21 
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/kthread.h>
25 #include <linux/delay.h>
26 #include <linux/ioport.h>
27 #include <linux/miscdevice.h>
28 #include <linux/kmod.h>
29 #include <linux/reboot.h>
30 
31 #include <asm/ebus.h>
32 #include <asm/uaccess.h>
33 #include <asm/envctrl.h>
34 #include <asm/io.h>
35 
36 #define ENVCTRL_MINOR	162
37 
38 #define PCF8584_ADDRESS	0x55
39 
40 #define CONTROL_PIN	0x80
41 #define CONTROL_ES0	0x40
42 #define CONTROL_ES1	0x20
43 #define CONTROL_ES2	0x10
44 #define CONTROL_ENI	0x08
45 #define CONTROL_STA	0x04
46 #define CONTROL_STO	0x02
47 #define CONTROL_ACK	0x01
48 
49 #define STATUS_PIN	0x80
50 #define STATUS_STS	0x20
51 #define STATUS_BER	0x10
52 #define STATUS_LRB	0x08
53 #define STATUS_AD0	0x08
54 #define STATUS_AAB	0x04
55 #define STATUS_LAB	0x02
56 #define STATUS_BB	0x01
57 
58 /*
59  * CLK Mode Register.
60  */
61 #define BUS_CLK_90	0x00
62 #define BUS_CLK_45	0x01
63 #define BUS_CLK_11	0x02
64 #define BUS_CLK_1_5	0x03
65 
66 #define CLK_3		0x00
67 #define CLK_4_43	0x10
68 #define CLK_6		0x14
69 #define CLK_8		0x18
70 #define CLK_12		0x1c
71 
72 #define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
73 #define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */
74 
75 /* Monitor type of i2c child device.
76  * Firmware definitions.
77  */
78 #define PCF8584_MAX_CHANNELS            8
79 #define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
80 #define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
81 #define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
82 #define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/
83 
84 /* Monitor type of i2c child device.
85  * Driver definitions.
86  */
87 #define ENVCTRL_NOMON				0
88 #define ENVCTRL_CPUTEMP_MON			1    /* cpu temperature monitor */
89 #define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
90 #define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
91 #define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperarture */
92 					     /* monitor                     */
93 #define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
94 #define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
95 #define ENVCTRL_SCSITEMP_MON		7    /* scsi temperarture */
96 #define ENVCTRL_GLOBALADDR_MON		8    /* global address */
97 
98 /* Child device type.
99  * Driver definitions.
100  */
101 #define I2C_ADC				0    /* pcf8591 */
102 #define I2C_GPIO			1    /* pcf8571 */
103 
104 /* Data read from child device may need to decode
105  * through a data table and a scale.
106  * Translation type as defined by firmware.
107  */
108 #define ENVCTRL_TRANSLATE_NO		0
109 #define ENVCTRL_TRANSLATE_PARTIAL	1
110 #define ENVCTRL_TRANSLATE_COMBINED	2
111 #define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
112 #define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */
113 
114 /* Driver miscellaneous definitions. */
115 #define ENVCTRL_MAX_CPU			4
116 #define CHANNEL_DESC_SZ			256
117 
118 /* Mask values for combined GlobalAddress/PowerStatus node */
119 #define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
120 #define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60
121 
122 /* Node 0x70 ignored on CompactPCI CP1400/1500 platforms
123  * (see envctrl_init_i2c_child)
124  */
125 #define ENVCTRL_CPCI_IGNORED_NODE		0x70
126 
127 #define PCF8584_DATA	0x00
128 #define PCF8584_CSR	0x01
129 
130 /* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
131  * Property of a port or channel as defined by the firmware.
132  */
133 struct pcf8584_channel {
134         unsigned char chnl_no;
135         unsigned char io_direction;
136         unsigned char type;
137         unsigned char last;
138 };
139 
140 /* Each child device may have one or more tables of bytes to help decode
141  * data. Table property as defined by the firmware.
142  */
143 struct pcf8584_tblprop {
144         unsigned int type;
145         unsigned int scale;
146         unsigned int offset; /* offset from the beginning of the table */
147         unsigned int size;
148 };
149 
150 /* i2c child */
151 struct i2c_child_t {
152 	/* Either ADC or GPIO. */
153 	unsigned char i2ctype;
154         unsigned long addr;
155         struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];
156 
157 	/* Channel info. */
158 	unsigned int total_chnls;	/* Number of monitor channels. */
159 	unsigned char fan_mask;		/* Byte mask for fan status channels. */
160 	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
161         struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];
162 
163 	/* Properties of all monitor channels. */
164 	unsigned int total_tbls;	/* Number of monitor tables. */
165         char *tables;			/* Pointer to table(s). */
166 	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
167 	char mon_type[PCF8584_MAX_CHANNELS];
168 };
169 
170 static void __iomem *i2c;
171 static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
172 static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
173 static unsigned int warning_temperature = 0;
174 static unsigned int shutdown_temperature = 0;
175 static char read_cpu;
176 
177 /* Forward declarations. */
178 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);
179 
180 /* Function Description: Test the PIN bit (Pending Interrupt Not)
181  * 			 to test when serial transmission is completed .
182  * Return : None.
183  */
184 static void envtrl_i2c_test_pin(void)
185 {
186 	int limit = 1000000;
187 
188 	while (--limit > 0) {
189 		if (!(readb(i2c + PCF8584_CSR) & STATUS_PIN))
190 			break;
191 		udelay(1);
192 	}
193 
194 	if (limit <= 0)
195 		printk(KERN_INFO "envctrl: Pin status will not clear.\n");
196 }
197 
198 /* Function Description: Test busy bit.
199  * Return : None.
200  */
201 static void envctrl_i2c_test_bb(void)
202 {
203 	int limit = 1000000;
204 
205 	while (--limit > 0) {
206 		/* Busy bit 0 means busy. */
207 		if (readb(i2c + PCF8584_CSR) & STATUS_BB)
208 			break;
209 		udelay(1);
210 	}
211 
212 	if (limit <= 0)
213 		printk(KERN_INFO "envctrl: Busy bit will not clear.\n");
214 }
215 
216 /* Function Description: Send the address for a read access.
217  * Return : 0 if not acknowledged, otherwise acknowledged.
218  */
219 static int envctrl_i2c_read_addr(unsigned char addr)
220 {
221 	envctrl_i2c_test_bb();
222 
223 	/* Load address. */
224 	writeb(addr + 1, i2c + PCF8584_DATA);
225 
226 	envctrl_i2c_test_bb();
227 
228 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
229 
230 	/* Wait for PIN. */
231 	envtrl_i2c_test_pin();
232 
233 	/* CSR 0 means acknowledged. */
234 	if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
235 		return readb(i2c + PCF8584_DATA);
236 	} else {
237 		writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
238 		return 0;
239 	}
240 }
241 
242 /* Function Description: Send the address for write mode.
243  * Return : None.
244  */
245 static void envctrl_i2c_write_addr(unsigned char addr)
246 {
247 	envctrl_i2c_test_bb();
248 	writeb(addr, i2c + PCF8584_DATA);
249 
250 	/* Generate Start condition. */
251 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
252 }
253 
254 /* Function Description: Read 1 byte of data from addr
255  *			 set by envctrl_i2c_read_addr()
256  * Return : Data from address set by envctrl_i2c_read_addr().
257  */
258 static unsigned char envctrl_i2c_read_data(void)
259 {
260 	envtrl_i2c_test_pin();
261 	writeb(CONTROL_ES0, i2c + PCF8584_CSR);  /* Send neg ack. */
262 	return readb(i2c + PCF8584_DATA);
263 }
264 
265 /* Function Description: Instruct the device which port to read data from.
266  * Return : None.
267  */
268 static void envctrl_i2c_write_data(unsigned char port)
269 {
270 	envtrl_i2c_test_pin();
271 	writeb(port, i2c + PCF8584_DATA);
272 }
273 
274 /* Function Description: Generate Stop condition after last byte is sent.
275  * Return : None.
276  */
277 static void envctrl_i2c_stop(void)
278 {
279 	envtrl_i2c_test_pin();
280 	writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
281 }
282 
283 /* Function Description: Read adc device.
284  * Return : Data at address and port.
285  */
286 static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
287 {
288 	/* Send address. */
289 	envctrl_i2c_write_addr(addr);
290 
291 	/* Setup port to read. */
292 	envctrl_i2c_write_data(port);
293 	envctrl_i2c_stop();
294 
295 	/* Read port. */
296 	envctrl_i2c_read_addr(addr);
297 
298 	/* Do a single byte read and send stop. */
299 	envctrl_i2c_read_data();
300 	envctrl_i2c_stop();
301 
302 	return readb(i2c + PCF8584_DATA);
303 }
304 
305 /* Function Description: Read gpio device.
306  * Return : Data at address.
307  */
308 static unsigned char envctrl_i2c_read_8574(unsigned char addr)
309 {
310 	unsigned char rd;
311 
312 	envctrl_i2c_read_addr(addr);
313 
314 	/* Do a single byte read and send stop. */
315 	rd = envctrl_i2c_read_data();
316 	envctrl_i2c_stop();
317 	return rd;
318 }
319 
320 /* Function Description: Decode data read from an adc device using firmware
321  *                       table.
322  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
323  */
324 static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
325 				      int scale, char *tbl, char *bufdata)
326 {
327 	int len = 0;
328 
329 	switch (translate_type) {
330 	case ENVCTRL_TRANSLATE_NO:
331 		/* No decode necessary. */
332 		len = 1;
333 		bufdata[0] = data;
334 		break;
335 
336 	case ENVCTRL_TRANSLATE_FULL:
337 		/* Decode this way: data = table[data]. */
338 		len = 1;
339 		bufdata[0] = tbl[data];
340 		break;
341 
342 	case ENVCTRL_TRANSLATE_SCALE:
343 		/* Decode this way: data = table[data]/scale */
344 		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
345 		len = strlen(bufdata);
346 		bufdata[len - 1] = bufdata[len - 2];
347 		bufdata[len - 2] = '.';
348 		break;
349 
350 	default:
351 		break;
352 	};
353 
354 	return len;
355 }
356 
357 /* Function Description: Read cpu-related data such as cpu temperature, voltage.
358  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
359  */
360 static int envctrl_read_cpu_info(int cpu, struct i2c_child_t *pchild,
361 				 char mon_type, unsigned char *bufdata)
362 {
363 	unsigned char data;
364 	int i;
365 	char *tbl, j = -1;
366 
367 	/* Find the right monitor type and channel. */
368 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
369 		if (pchild->mon_type[i] == mon_type) {
370 			if (++j == cpu) {
371 				break;
372 			}
373 		}
374 	}
375 
376 	if (j != cpu)
377 		return 0;
378 
379         /* Read data from address and port. */
380 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
381 				     (unsigned char)pchild->chnl_array[i].chnl_no);
382 
383 	/* Find decoding table. */
384 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
385 
386 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
387 					  pchild->tblprop_array[i].scale,
388 					  tbl, bufdata);
389 }
390 
391 /* Function Description: Read noncpu-related data such as motherboard
392  *                       temperature.
393  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
394  */
395 static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
396 				    char mon_type, unsigned char *bufdata)
397 {
398 	unsigned char data;
399 	int i;
400 	char *tbl = NULL;
401 
402 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
403 		if (pchild->mon_type[i] == mon_type)
404 			break;
405 	}
406 
407 	if (i >= PCF8584_MAX_CHANNELS)
408 		return 0;
409 
410         /* Read data from address and port. */
411 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
412 				     (unsigned char)pchild->chnl_array[i].chnl_no);
413 
414 	/* Find decoding table. */
415 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
416 
417 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
418 					  pchild->tblprop_array[i].scale,
419 					  tbl, bufdata);
420 }
421 
422 /* Function Description: Read fan status.
423  * Return : Always 1 byte. Status stored in bufdata.
424  */
425 static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
426 				  unsigned char data,
427 				  char *bufdata)
428 {
429 	unsigned char tmp, ret = 0;
430 	int i, j = 0;
431 
432 	tmp = data & pchild->fan_mask;
433 
434 	if (tmp == pchild->fan_mask) {
435 		/* All bits are on. All fans are functioning. */
436 		ret = ENVCTRL_ALL_FANS_GOOD;
437 	} else if (tmp == 0) {
438 		/* No bits are on. No fans are functioning. */
439 		ret = ENVCTRL_ALL_FANS_BAD;
440 	} else {
441 		/* Go through all channels, mark 'on' the matched bits.
442 		 * Notice that fan_mask may have discontiguous bits but
443 		 * return mask are always contiguous. For example if we
444 		 * monitor 4 fans at channels 0,1,2,4, the return mask
445 		 * should be 00010000 if only fan at channel 4 is working.
446 		 */
447 		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
448 			if (pchild->fan_mask & chnls_mask[i]) {
449 				if (!(chnls_mask[i] & tmp))
450 					ret |= chnls_mask[j];
451 
452 				j++;
453 			}
454 		}
455 	}
456 
457 	bufdata[0] = ret;
458 	return 1;
459 }
460 
461 /* Function Description: Read global addressing line.
462  * Return : Always 1 byte. Status stored in bufdata.
463  */
464 static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
465 				  unsigned char data,
466 				  char *bufdata)
467 {
468 	/* Translatation table is not necessary, as global
469 	 * addr is the integer value of the GA# bits.
470 	 *
471 	 * NOTE: MSB is documented as zero, but I see it as '1' always....
472 	 *
473 	 * -----------------------------------------------
474 	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
475 	 * -----------------------------------------------
476 	 * GA0 - GA4	integer value of Global Address (backplane slot#)
477 	 * DEG			0 = cPCI Power supply output is starting to degrade
478 	 * 				1 = cPCI Power supply output is OK
479 	 * FAL			0 = cPCI Power supply has failed
480 	 * 				1 = cPCI Power supply output is OK
481 	 */
482 	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
483 	return 1;
484 }
485 
486 /* Function Description: Read standard voltage and power supply status.
487  * Return : Always 1 byte. Status stored in bufdata.
488  */
489 static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
490 						unsigned char data,
491 						char *bufdata)
492 {
493 	unsigned char tmp, ret = 0;
494 	int i, j = 0;
495 
496 	tmp = data & pchild->voltage_mask;
497 
498 	/* Two channels are used to monitor voltage and power supply. */
499 	if (tmp == pchild->voltage_mask) {
500 		/* All bits are on. Voltage and power supply are okay. */
501 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
502 	} else if (tmp == 0) {
503 		/* All bits are off. Voltage and power supply are bad */
504 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
505 	} else {
506 		/* Either voltage or power supply has problem. */
507 		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
508 			if (pchild->voltage_mask & chnls_mask[i]) {
509 				j++;
510 
511 				/* Break out when there is a mismatch. */
512 				if (!(chnls_mask[i] & tmp))
513 					break;
514 			}
515 		}
516 
517 		/* Make a wish that hardware will always use the
518 		 * first channel for voltage and the second for
519 		 * power supply.
520 		 */
521 		if (j == 1)
522 			ret = ENVCTRL_VOLTAGE_BAD;
523 		else
524 			ret = ENVCTRL_POWERSUPPLY_BAD;
525 	}
526 
527 	bufdata[0] = ret;
528 	return 1;
529 }
530 
531 /* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
532  * Return: Number of read bytes. 0 for error.
533  */
534 static ssize_t
535 envctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
536 {
537 	struct i2c_child_t *pchild;
538 	unsigned char data[10];
539 	int ret = 0;
540 
541 	/* Get the type of read as decided in ioctl() call.
542 	 * Find the appropriate i2c child.
543 	 * Get the data and put back to the user buffer.
544 	 */
545 
546 	switch ((int)(long)file->private_data) {
547 	case ENVCTRL_RD_WARNING_TEMPERATURE:
548 		if (warning_temperature == 0)
549 			return 0;
550 
551 		data[0] = (unsigned char)(warning_temperature);
552 		ret = 1;
553 		if (copy_to_user(buf, data, ret))
554 			ret = -EFAULT;
555 		break;
556 
557 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
558 		if (shutdown_temperature == 0)
559 			return 0;
560 
561 		data[0] = (unsigned char)(shutdown_temperature);
562 		ret = 1;
563 		if (copy_to_user(buf, data, ret))
564 			ret = -EFAULT;
565 		break;
566 
567 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
568 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
569 			return 0;
570 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
571 		if (copy_to_user(buf, data, ret))
572 			ret = -EFAULT;
573 		break;
574 
575 	case ENVCTRL_RD_CPU_TEMPERATURE:
576 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
577 			return 0;
578 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUTEMP_MON, data);
579 
580 		/* Reset cpu to the default cpu0. */
581 		if (copy_to_user(buf, data, ret))
582 			ret = -EFAULT;
583 		break;
584 
585 	case ENVCTRL_RD_CPU_VOLTAGE:
586 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
587 			return 0;
588 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUVOLTAGE_MON, data);
589 
590 		/* Reset cpu to the default cpu0. */
591 		if (copy_to_user(buf, data, ret))
592 			ret = -EFAULT;
593 		break;
594 
595 	case ENVCTRL_RD_SCSI_TEMPERATURE:
596 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
597 			return 0;
598 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
599 		if (copy_to_user(buf, data, ret))
600 			ret = -EFAULT;
601 		break;
602 
603 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
604 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
605 			return 0;
606 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
607 		if (copy_to_user(buf, data, ret))
608 			ret = -EFAULT;
609 		break;
610 
611 	case ENVCTRL_RD_FAN_STATUS:
612 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
613 			return 0;
614 		data[0] = envctrl_i2c_read_8574(pchild->addr);
615 		ret = envctrl_i2c_fan_status(pchild,data[0], data);
616 		if (copy_to_user(buf, data, ret))
617 			ret = -EFAULT;
618 		break;
619 
620 	case ENVCTRL_RD_GLOBALADDRESS:
621 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
622 			return 0;
623 		data[0] = envctrl_i2c_read_8574(pchild->addr);
624 		ret = envctrl_i2c_globaladdr(pchild, data[0], data);
625 		if (copy_to_user(buf, data, ret))
626 			ret = -EFAULT;
627 		break;
628 
629 	case ENVCTRL_RD_VOLTAGE_STATUS:
630 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
631 			/* If voltage monitor not present, check for CPCI equivalent */
632 			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
633 				return 0;
634 		data[0] = envctrl_i2c_read_8574(pchild->addr);
635 		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
636 		if (copy_to_user(buf, data, ret))
637 			ret = -EFAULT;
638 		break;
639 
640 	default:
641 		break;
642 
643 	};
644 
645 	return ret;
646 }
647 
648 /* Function Description: Command what to read.  Mapped to user ioctl().
649  * Return: Gives 0 for implemented commands, -EINVAL otherwise.
650  */
651 static long
652 envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
653 {
654 	char __user *infobuf;
655 
656 	switch (cmd) {
657 	case ENVCTRL_RD_WARNING_TEMPERATURE:
658 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
659 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
660 	case ENVCTRL_RD_FAN_STATUS:
661 	case ENVCTRL_RD_VOLTAGE_STATUS:
662 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
663 	case ENVCTRL_RD_SCSI_TEMPERATURE:
664 	case ENVCTRL_RD_GLOBALADDRESS:
665 		file->private_data = (void *)(long)cmd;
666 		break;
667 
668 	case ENVCTRL_RD_CPU_TEMPERATURE:
669 	case ENVCTRL_RD_CPU_VOLTAGE:
670 		/* Check to see if application passes in any cpu number,
671 		 * the default is cpu0.
672 		 */
673 		infobuf = (char __user *) arg;
674 		if (infobuf == NULL) {
675 			read_cpu = 0;
676 		}else {
677 			get_user(read_cpu, infobuf);
678 		}
679 
680 		/* Save the command for use when reading. */
681 		file->private_data = (void *)(long)cmd;
682 		break;
683 
684 	default:
685 		return -EINVAL;
686 	};
687 
688 	return 0;
689 }
690 
691 /* Function Description: open device. Mapped to user open().
692  * Return: Always 0.
693  */
694 static int
695 envctrl_open(struct inode *inode, struct file *file)
696 {
697 	file->private_data = NULL;
698 	return 0;
699 }
700 
701 /* Function Description: Open device. Mapped to user close().
702  * Return: Always 0.
703  */
704 static int
705 envctrl_release(struct inode *inode, struct file *file)
706 {
707 	return 0;
708 }
709 
710 static const struct file_operations envctrl_fops = {
711 	.owner =		THIS_MODULE,
712 	.read =			envctrl_read,
713 	.unlocked_ioctl =	envctrl_ioctl,
714 #ifdef CONFIG_COMPAT
715 	.compat_ioctl =		envctrl_ioctl,
716 #endif
717 	.open =			envctrl_open,
718 	.release =		envctrl_release,
719 };
720 
721 static struct miscdevice envctrl_dev = {
722 	ENVCTRL_MINOR,
723 	"envctrl",
724 	&envctrl_fops
725 };
726 
727 /* Function Description: Set monitor type based on firmware description.
728  * Return: None.
729  */
730 static void envctrl_set_mon(struct i2c_child_t *pchild,
731 			    const char *chnl_desc,
732 			    int chnl_no)
733 {
734 	/* Firmware only has temperature type.  It does not distinguish
735 	 * different kinds of temperatures.  We use channel description
736 	 * to disinguish them.
737 	 */
738 	if (!(strcmp(chnl_desc,"temp,cpu")) ||
739 	    !(strcmp(chnl_desc,"temp,cpu0")) ||
740 	    !(strcmp(chnl_desc,"temp,cpu1")) ||
741 	    !(strcmp(chnl_desc,"temp,cpu2")) ||
742 	    !(strcmp(chnl_desc,"temp,cpu3")))
743 		pchild->mon_type[chnl_no] = ENVCTRL_CPUTEMP_MON;
744 
745 	if (!(strcmp(chnl_desc,"vddcore,cpu0")) ||
746 	    !(strcmp(chnl_desc,"vddcore,cpu1")) ||
747 	    !(strcmp(chnl_desc,"vddcore,cpu2")) ||
748 	    !(strcmp(chnl_desc,"vddcore,cpu3")))
749 		pchild->mon_type[chnl_no] = ENVCTRL_CPUVOLTAGE_MON;
750 
751 	if (!(strcmp(chnl_desc,"temp,motherboard")))
752 		pchild->mon_type[chnl_no] = ENVCTRL_MTHRBDTEMP_MON;
753 
754 	if (!(strcmp(chnl_desc,"temp,scsi")))
755 		pchild->mon_type[chnl_no] = ENVCTRL_SCSITEMP_MON;
756 
757 	if (!(strcmp(chnl_desc,"temp,ethernet")))
758 		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
759 }
760 
761 /* Function Description: Initialize monitor channel with channel desc,
762  *                       decoding tables, monitor type, optional properties.
763  * Return: None.
764  */
765 static void envctrl_init_adc(struct i2c_child_t *pchild, struct device_node *dp)
766 {
767 	int i = 0, len;
768 	const char *pos;
769 	const unsigned int *pval;
770 
771 	/* Firmware describe channels into a stream separated by a '\0'. */
772 	pos = of_get_property(dp, "channels-description", &len);
773 
774 	while (len > 0) {
775 		int l = strlen(pos) + 1;
776 		envctrl_set_mon(pchild, pos, i++);
777 		len -= l;
778 		pos += l;
779 	}
780 
781 	/* Get optional properties. */
782 	pval = of_get_property(dp, "warning-temp", NULL);
783 	if (pval)
784 		warning_temperature = *pval;
785 
786 	pval = of_get_property(dp, "shutdown-temp", NULL);
787 	if (pval)
788 		shutdown_temperature = *pval;
789 }
790 
791 /* Function Description: Initialize child device monitoring fan status.
792  * Return: None.
793  */
794 static void envctrl_init_fanstat(struct i2c_child_t *pchild)
795 {
796 	int i;
797 
798 	/* Go through all channels and set up the mask. */
799 	for (i = 0; i < pchild->total_chnls; i++)
800 		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
801 
802 	/* We only need to know if this child has fan status monitored.
803 	 * We don't care which channels since we have the mask already.
804 	 */
805 	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
806 }
807 
808 /* Function Description: Initialize child device for global addressing line.
809  * Return: None.
810  */
811 static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
812 {
813 	int i;
814 
815 	/* Voltage/PowerSupply monitoring is piggybacked
816 	 * with Global Address on CompactPCI.  See comments
817 	 * within envctrl_i2c_globaladdr for bit assignments.
818 	 *
819 	 * The mask is created here by assigning mask bits to each
820 	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
821 	 * Channel numbers are not consecutive within the globaladdr
822 	 * node (why?), so we use the actual counter value as chnls_mask
823 	 * index instead of the chnl_array[x].chnl_no value.
824 	 *
825 	 * NOTE: This loop could be replaced with a constant representing
826 	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
827 	 */
828 	for (i = 0; i < pchild->total_chnls; i++) {
829 		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
830 			pchild->voltage_mask |= chnls_mask[i];
831 		}
832 	}
833 
834 	/* We only need to know if this child has global addressing
835 	 * line monitored.  We don't care which channels since we know
836 	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
837 	 */
838 	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
839 }
840 
841 /* Initialize child device monitoring voltage status. */
842 static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
843 {
844 	int i;
845 
846 	/* Go through all channels and set up the mask. */
847 	for (i = 0; i < pchild->total_chnls; i++)
848 		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
849 
850 	/* We only need to know if this child has voltage status monitored.
851 	 * We don't care which channels since we have the mask already.
852 	 */
853 	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
854 }
855 
856 /* Function Description: Initialize i2c child device.
857  * Return: None.
858  */
859 static void envctrl_init_i2c_child(struct linux_ebus_child *edev_child,
860 				   struct i2c_child_t *pchild)
861 {
862 	int len, i, tbls_size = 0;
863 	struct device_node *dp = edev_child->prom_node;
864 	const void *pval;
865 
866 	/* Get device address. */
867 	pval = of_get_property(dp, "reg", &len);
868 	memcpy(&pchild->addr, pval, len);
869 
870 	/* Get tables property.  Read firmware temperature tables. */
871 	pval = of_get_property(dp, "translation", &len);
872 	if (pval && len > 0) {
873 		memcpy(pchild->tblprop_array, pval, len);
874                 pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
875 		for (i = 0; i < pchild->total_tbls; i++) {
876 			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
877 				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
878 			}
879 		}
880 
881                 pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
882 		if (pchild->tables == NULL){
883 			printk("envctrl: Failed to allocate table.\n");
884 			return;
885 		}
886 		pval = of_get_property(dp, "tables", &len);
887                 if (!pval || len <= 0) {
888 			printk("envctrl: Failed to get table.\n");
889 			return;
890 		}
891 		memcpy(pchild->tables, pval, len);
892 	}
893 
894 	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
895 	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
896 	 * "For Factory Use Only."
897 	 *
898 	 * We ignore the node on these platforms by assigning the
899 	 * 'NULL' monitor type.
900 	 */
901 	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
902 		struct device_node *root_node;
903 		int len;
904 
905 		root_node = of_find_node_by_path("/");
906 		if (!strcmp(root_node->name, "SUNW,UltraSPARC-IIi-cEngine")) {
907 			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
908 				pchild->mon_type[len] = ENVCTRL_NOMON;
909 			}
910 			return;
911 		}
912 	}
913 
914 	/* Get the monitor channels. */
915 	pval = of_get_property(dp, "channels-in-use", &len);
916 	memcpy(pchild->chnl_array, pval, len);
917 	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
918 
919 	for (i = 0; i < pchild->total_chnls; i++) {
920 		switch (pchild->chnl_array[i].type) {
921 		case PCF8584_TEMP_TYPE:
922 			envctrl_init_adc(pchild, dp);
923 			break;
924 
925 		case PCF8584_GLOBALADDR_TYPE:
926 			envctrl_init_globaladdr(pchild);
927 			i = pchild->total_chnls;
928 			break;
929 
930 		case PCF8584_FANSTAT_TYPE:
931 			envctrl_init_fanstat(pchild);
932 			i = pchild->total_chnls;
933 			break;
934 
935 		case PCF8584_VOLTAGE_TYPE:
936 			if (pchild->i2ctype == I2C_ADC) {
937 				envctrl_init_adc(pchild,dp);
938 			} else {
939 				envctrl_init_voltage_status(pchild);
940 			}
941 			i = pchild->total_chnls;
942 			break;
943 
944 		default:
945 			break;
946 		};
947 	}
948 }
949 
950 /* Function Description: Search the child device list for a device.
951  * Return : The i2c child if found. NULL otherwise.
952  */
953 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
954 {
955 	int i, j;
956 
957 	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
958 		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
959 			if (i2c_childlist[i].mon_type[j] == mon_type) {
960 				return (struct i2c_child_t *)(&(i2c_childlist[i]));
961 			}
962 		}
963 	}
964 	return NULL;
965 }
966 
967 static void envctrl_do_shutdown(void)
968 {
969 	static int inprog = 0;
970 	int ret;
971 
972 	if (inprog != 0)
973 		return;
974 
975 	inprog = 1;
976 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
977 	ret = orderly_poweroff(true);
978 	if (ret < 0) {
979 		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n");
980 		inprog = 0;  /* unlikely to succeed, but we could try again */
981 	}
982 }
983 
984 static struct task_struct *kenvctrld_task;
985 
986 static int kenvctrld(void *__unused)
987 {
988 	int poll_interval;
989 	int whichcpu;
990 	char tempbuf[10];
991 	struct i2c_child_t *cputemp;
992 
993 	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
994 		printk(KERN_ERR
995 		       "envctrl: kenvctrld unable to monitor CPU temp-- exiting\n");
996 		return -ENODEV;
997 	}
998 
999 	poll_interval = 5000; /* TODO env_mon_interval */
1000 
1001 	printk(KERN_INFO "envctrl: %s starting...\n", current->comm);
1002 	for (;;) {
1003 		msleep_interruptible(poll_interval);
1004 
1005 		if (kthread_should_stop())
1006 			break;
1007 
1008 		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
1009 			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
1010 						      ENVCTRL_CPUTEMP_MON,
1011 						      tempbuf)) {
1012 				if (tempbuf[0] >= shutdown_temperature) {
1013 					printk(KERN_CRIT
1014 						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
1015 						"shutdown threshold %i C\n",
1016 						current->comm, whichcpu,
1017 						tempbuf[0], shutdown_temperature);
1018 					envctrl_do_shutdown();
1019 				}
1020 			}
1021 		}
1022 	}
1023 	printk(KERN_INFO "envctrl: %s exiting...\n", current->comm);
1024 	return 0;
1025 }
1026 
1027 static int __init envctrl_init(void)
1028 {
1029 	struct linux_ebus *ebus = NULL;
1030 	struct linux_ebus_device *edev = NULL;
1031 	struct linux_ebus_child *edev_child = NULL;
1032 	int err, i = 0;
1033 
1034 	for_each_ebus(ebus) {
1035 		for_each_ebusdev(edev, ebus) {
1036 			if (!strcmp(edev->prom_node->name, "bbc")) {
1037 				/* If we find a boot-bus controller node,
1038 				 * then this envctrl driver is not for us.
1039 				 */
1040 				return -ENODEV;
1041 			}
1042 		}
1043 	}
1044 
1045 	/* Traverse through ebus and ebus device list for i2c device and
1046 	 * adc and gpio nodes.
1047 	 */
1048 	for_each_ebus(ebus) {
1049 		for_each_ebusdev(edev, ebus) {
1050 			if (!strcmp(edev->prom_node->name, "i2c")) {
1051 				i2c = ioremap(edev->resource[0].start, 0x2);
1052 				for_each_edevchild(edev, edev_child) {
1053 					if (!strcmp("gpio", edev_child->prom_node->name)) {
1054 						i2c_childlist[i].i2ctype = I2C_GPIO;
1055 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1056 					}
1057 					if (!strcmp("adc", edev_child->prom_node->name)) {
1058 						i2c_childlist[i].i2ctype = I2C_ADC;
1059 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1060 					}
1061 				}
1062 				goto done;
1063 			}
1064 		}
1065 	}
1066 
1067 done:
1068 	if (!edev) {
1069 		printk("envctrl: I2C device not found.\n");
1070 		return -ENODEV;
1071 	}
1072 
1073 	/* Set device address. */
1074 	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
1075 	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
1076 
1077 	/* Set system clock and SCL frequencies. */
1078 	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
1079 	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
1080 
1081 	/* Enable serial interface. */
1082 	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
1083 	udelay(200);
1084 
1085 	/* Register the device as a minor miscellaneous device. */
1086 	err = misc_register(&envctrl_dev);
1087 	if (err) {
1088 		printk("envctrl: Unable to get misc minor %d\n",
1089 		       envctrl_dev.minor);
1090 		goto out_iounmap;
1091 	}
1092 
1093 	/* Note above traversal routine post-incremented 'i' to accommodate
1094 	 * a next child device, so we decrement before reverse-traversal of
1095 	 * child devices.
1096 	 */
1097 	printk("envctrl: initialized ");
1098 	for (--i; i >= 0; --i) {
1099 		printk("[%s 0x%lx]%s",
1100 			(I2C_ADC == i2c_childlist[i].i2ctype) ? ("adc") :
1101 			((I2C_GPIO == i2c_childlist[i].i2ctype) ? ("gpio") : ("unknown")),
1102 			i2c_childlist[i].addr, (0 == i) ? ("\n") : (" "));
1103 	}
1104 
1105 	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
1106 	if (IS_ERR(kenvctrld_task)) {
1107 		err = PTR_ERR(kenvctrld_task);
1108 		goto out_deregister;
1109 	}
1110 
1111 	return 0;
1112 
1113 out_deregister:
1114 	misc_deregister(&envctrl_dev);
1115 out_iounmap:
1116 	iounmap(i2c);
1117 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1118 		kfree(i2c_childlist[i].tables);
1119 
1120 	return err;
1121 }
1122 
1123 static void __exit envctrl_cleanup(void)
1124 {
1125 	int i;
1126 
1127 	kthread_stop(kenvctrld_task);
1128 
1129 	iounmap(i2c);
1130 	misc_deregister(&envctrl_dev);
1131 
1132 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1133 		kfree(i2c_childlist[i].tables);
1134 }
1135 
1136 module_init(envctrl_init);
1137 module_exit(envctrl_cleanup);
1138 MODULE_LICENSE("GPL");
1139