xref: /openbmc/linux/drivers/sbus/char/envctrl.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
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/config.h>
23 #include <linux/module.h>
24 #include <linux/sched.h>
25 #include <linux/errno.h>
26 #include <linux/delay.h>
27 #include <linux/ioport.h>
28 #include <linux/init.h>
29 #include <linux/miscdevice.h>
30 #include <linux/mm.h>
31 #include <linux/slab.h>
32 #include <linux/kernel.h>
33 
34 #include <asm/ebus.h>
35 #include <asm/uaccess.h>
36 #include <asm/envctrl.h>
37 
38 #define __KERNEL_SYSCALLS__
39 static int errno;
40 #include <asm/unistd.h>
41 
42 #define ENVCTRL_MINOR	162
43 
44 #define PCF8584_ADDRESS	0x55
45 
46 #define CONTROL_PIN	0x80
47 #define CONTROL_ES0	0x40
48 #define CONTROL_ES1	0x20
49 #define CONTROL_ES2	0x10
50 #define CONTROL_ENI	0x08
51 #define CONTROL_STA	0x04
52 #define CONTROL_STO	0x02
53 #define CONTROL_ACK	0x01
54 
55 #define STATUS_PIN	0x80
56 #define STATUS_STS	0x20
57 #define STATUS_BER	0x10
58 #define STATUS_LRB	0x08
59 #define STATUS_AD0	0x08
60 #define STATUS_AAB	0x04
61 #define STATUS_LAB	0x02
62 #define STATUS_BB	0x01
63 
64 /*
65  * CLK Mode Register.
66  */
67 #define BUS_CLK_90	0x00
68 #define BUS_CLK_45	0x01
69 #define BUS_CLK_11	0x02
70 #define BUS_CLK_1_5	0x03
71 
72 #define CLK_3		0x00
73 #define CLK_4_43	0x10
74 #define CLK_6		0x14
75 #define CLK_8		0x18
76 #define CLK_12		0x1c
77 
78 #define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
79 #define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */
80 
81 /* Monitor type of i2c child device.
82  * Firmware definitions.
83  */
84 #define PCF8584_MAX_CHANNELS            8
85 #define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
86 #define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
87 #define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
88 #define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/
89 
90 /* Monitor type of i2c child device.
91  * Driver definitions.
92  */
93 #define ENVCTRL_NOMON				0
94 #define ENVCTRL_CPUTEMP_MON			1    /* cpu temperature monitor */
95 #define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
96 #define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
97 #define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperarture */
98 					     /* monitor                     */
99 #define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
100 #define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
101 #define ENVCTRL_SCSITEMP_MON		7    /* scsi temperarture */
102 #define ENVCTRL_GLOBALADDR_MON		8    /* global address */
103 
104 /* Child device type.
105  * Driver definitions.
106  */
107 #define I2C_ADC				0    /* pcf8591 */
108 #define I2C_GPIO			1    /* pcf8571 */
109 
110 /* Data read from child device may need to decode
111  * through a data table and a scale.
112  * Translation type as defined by firmware.
113  */
114 #define ENVCTRL_TRANSLATE_NO		0
115 #define ENVCTRL_TRANSLATE_PARTIAL	1
116 #define ENVCTRL_TRANSLATE_COMBINED	2
117 #define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
118 #define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */
119 
120 /* Driver miscellaneous definitions. */
121 #define ENVCTRL_MAX_CPU			4
122 #define CHANNEL_DESC_SZ			256
123 
124 /* Mask values for combined GlobalAddress/PowerStatus node */
125 #define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
126 #define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60
127 
128 /* Node 0x70 ignored on CompactPCI CP1400/1500 platforms
129  * (see envctrl_init_i2c_child)
130  */
131 #define ENVCTRL_CPCI_IGNORED_NODE		0x70
132 
133 #define PCF8584_DATA	0x00
134 #define PCF8584_CSR	0x01
135 
136 /* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
137  * Property of a port or channel as defined by the firmware.
138  */
139 struct pcf8584_channel {
140         unsigned char chnl_no;
141         unsigned char io_direction;
142         unsigned char type;
143         unsigned char last;
144 };
145 
146 /* Each child device may have one or more tables of bytes to help decode
147  * data. Table property as defined by the firmware.
148  */
149 struct pcf8584_tblprop {
150         unsigned int type;
151         unsigned int scale;
152         unsigned int offset; /* offset from the beginning of the table */
153         unsigned int size;
154 };
155 
156 /* i2c child */
157 struct i2c_child_t {
158 	/* Either ADC or GPIO. */
159 	unsigned char i2ctype;
160         unsigned long addr;
161         struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];
162 
163 	/* Channel info. */
164 	unsigned int total_chnls;	/* Number of monitor channels. */
165 	unsigned char fan_mask;		/* Byte mask for fan status channels. */
166 	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
167         struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];
168 
169 	/* Properties of all monitor channels. */
170 	unsigned int total_tbls;	/* Number of monitor tables. */
171         char *tables;			/* Pointer to table(s). */
172 	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
173 	char mon_type[PCF8584_MAX_CHANNELS];
174 };
175 
176 static void __iomem *i2c;
177 static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
178 static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
179 static unsigned int warning_temperature = 0;
180 static unsigned int shutdown_temperature = 0;
181 static char read_cpu;
182 
183 /* Forward declarations. */
184 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);
185 
186 /* Function Description: Test the PIN bit (Pending Interrupt Not)
187  * 			 to test when serial transmission is completed .
188  * Return : None.
189  */
190 static void envtrl_i2c_test_pin(void)
191 {
192 	int limit = 1000000;
193 
194 	while (--limit > 0) {
195 		if (!(readb(i2c + PCF8584_CSR) & STATUS_PIN))
196 			break;
197 		udelay(1);
198 	}
199 
200 	if (limit <= 0)
201 		printk(KERN_INFO "envctrl: Pin status will not clear.\n");
202 }
203 
204 /* Function Description: Test busy bit.
205  * Return : None.
206  */
207 static void envctrl_i2c_test_bb(void)
208 {
209 	int limit = 1000000;
210 
211 	while (--limit > 0) {
212 		/* Busy bit 0 means busy. */
213 		if (readb(i2c + PCF8584_CSR) & STATUS_BB)
214 			break;
215 		udelay(1);
216 	}
217 
218 	if (limit <= 0)
219 		printk(KERN_INFO "envctrl: Busy bit will not clear.\n");
220 }
221 
222 /* Function Description: Send the address for a read access.
223  * Return : 0 if not acknowledged, otherwise acknowledged.
224  */
225 static int envctrl_i2c_read_addr(unsigned char addr)
226 {
227 	envctrl_i2c_test_bb();
228 
229 	/* Load address. */
230 	writeb(addr + 1, i2c + PCF8584_DATA);
231 
232 	envctrl_i2c_test_bb();
233 
234 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
235 
236 	/* Wait for PIN. */
237 	envtrl_i2c_test_pin();
238 
239 	/* CSR 0 means acknowledged. */
240 	if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
241 		return readb(i2c + PCF8584_DATA);
242 	} else {
243 		writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
244 		return 0;
245 	}
246 }
247 
248 /* Function Description: Send the address for write mode.
249  * Return : None.
250  */
251 static void envctrl_i2c_write_addr(unsigned char addr)
252 {
253 	envctrl_i2c_test_bb();
254 	writeb(addr, i2c + PCF8584_DATA);
255 
256 	/* Generate Start condition. */
257 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
258 }
259 
260 /* Function Description: Read 1 byte of data from addr
261  *			 set by envctrl_i2c_read_addr()
262  * Return : Data from address set by envctrl_i2c_read_addr().
263  */
264 static unsigned char envctrl_i2c_read_data(void)
265 {
266 	envtrl_i2c_test_pin();
267 	writeb(CONTROL_ES0, i2c + PCF8584_CSR);  /* Send neg ack. */
268 	return readb(i2c + PCF8584_DATA);
269 }
270 
271 /* Function Description: Instruct the device which port to read data from.
272  * Return : None.
273  */
274 static void envctrl_i2c_write_data(unsigned char port)
275 {
276 	envtrl_i2c_test_pin();
277 	writeb(port, i2c + PCF8584_DATA);
278 }
279 
280 /* Function Description: Generate Stop condition after last byte is sent.
281  * Return : None.
282  */
283 static void envctrl_i2c_stop(void)
284 {
285 	envtrl_i2c_test_pin();
286 	writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
287 }
288 
289 /* Function Description: Read adc device.
290  * Return : Data at address and port.
291  */
292 static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
293 {
294 	/* Send address. */
295 	envctrl_i2c_write_addr(addr);
296 
297 	/* Setup port to read. */
298 	envctrl_i2c_write_data(port);
299 	envctrl_i2c_stop();
300 
301 	/* Read port. */
302 	envctrl_i2c_read_addr(addr);
303 
304 	/* Do a single byte read and send stop. */
305 	envctrl_i2c_read_data();
306 	envctrl_i2c_stop();
307 
308 	return readb(i2c + PCF8584_DATA);
309 }
310 
311 /* Function Description: Read gpio device.
312  * Return : Data at address.
313  */
314 static unsigned char envctrl_i2c_read_8574(unsigned char addr)
315 {
316 	unsigned char rd;
317 
318 	envctrl_i2c_read_addr(addr);
319 
320 	/* Do a single byte read and send stop. */
321 	rd = envctrl_i2c_read_data();
322 	envctrl_i2c_stop();
323 	return rd;
324 }
325 
326 /* Function Description: Decode data read from an adc device using firmware
327  *                       table.
328  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
329  */
330 static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
331 				      int scale, char *tbl, char *bufdata)
332 {
333 	int len = 0;
334 
335 	switch (translate_type) {
336 	case ENVCTRL_TRANSLATE_NO:
337 		/* No decode necessary. */
338 		len = 1;
339 		bufdata[0] = data;
340 		break;
341 
342 	case ENVCTRL_TRANSLATE_FULL:
343 		/* Decode this way: data = table[data]. */
344 		len = 1;
345 		bufdata[0] = tbl[data];
346 		break;
347 
348 	case ENVCTRL_TRANSLATE_SCALE:
349 		/* Decode this way: data = table[data]/scale */
350 		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
351 		len = strlen(bufdata);
352 		bufdata[len - 1] = bufdata[len - 2];
353 		bufdata[len - 2] = '.';
354 		break;
355 
356 	default:
357 		break;
358 	};
359 
360 	return len;
361 }
362 
363 /* Function Description: Read cpu-related data such as cpu temperature, voltage.
364  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
365  */
366 static int envctrl_read_cpu_info(int cpu, struct i2c_child_t *pchild,
367 				 char mon_type, unsigned char *bufdata)
368 {
369 	unsigned char data;
370 	int i;
371 	char *tbl, j = -1;
372 
373 	/* Find the right monitor type and channel. */
374 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
375 		if (pchild->mon_type[i] == mon_type) {
376 			if (++j == cpu) {
377 				break;
378 			}
379 		}
380 	}
381 
382 	if (j != cpu)
383 		return 0;
384 
385         /* Read data from address and port. */
386 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
387 				     (unsigned char)pchild->chnl_array[i].chnl_no);
388 
389 	/* Find decoding table. */
390 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
391 
392 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
393 					  pchild->tblprop_array[i].scale,
394 					  tbl, bufdata);
395 }
396 
397 /* Function Description: Read noncpu-related data such as motherboard
398  *                       temperature.
399  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
400  */
401 static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
402 				    char mon_type, unsigned char *bufdata)
403 {
404 	unsigned char data;
405 	int i;
406 	char *tbl = NULL;
407 
408 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
409 		if (pchild->mon_type[i] == mon_type)
410 			break;
411 	}
412 
413 	if (i >= PCF8584_MAX_CHANNELS)
414 		return 0;
415 
416         /* Read data from address and port. */
417 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
418 				     (unsigned char)pchild->chnl_array[i].chnl_no);
419 
420 	/* Find decoding table. */
421 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
422 
423 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
424 					  pchild->tblprop_array[i].scale,
425 					  tbl, bufdata);
426 }
427 
428 /* Function Description: Read fan status.
429  * Return : Always 1 byte. Status stored in bufdata.
430  */
431 static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
432 				  unsigned char data,
433 				  char *bufdata)
434 {
435 	unsigned char tmp, ret = 0;
436 	int i, j = 0;
437 
438 	tmp = data & pchild->fan_mask;
439 
440 	if (tmp == pchild->fan_mask) {
441 		/* All bits are on. All fans are functioning. */
442 		ret = ENVCTRL_ALL_FANS_GOOD;
443 	} else if (tmp == 0) {
444 		/* No bits are on. No fans are functioning. */
445 		ret = ENVCTRL_ALL_FANS_BAD;
446 	} else {
447 		/* Go through all channels, mark 'on' the matched bits.
448 		 * Notice that fan_mask may have discontiguous bits but
449 		 * return mask are always contiguous. For example if we
450 		 * monitor 4 fans at channels 0,1,2,4, the return mask
451 		 * should be 00010000 if only fan at channel 4 is working.
452 		 */
453 		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
454 			if (pchild->fan_mask & chnls_mask[i]) {
455 				if (!(chnls_mask[i] & tmp))
456 					ret |= chnls_mask[j];
457 
458 				j++;
459 			}
460 		}
461 	}
462 
463 	bufdata[0] = ret;
464 	return 1;
465 }
466 
467 /* Function Description: Read global addressing line.
468  * Return : Always 1 byte. Status stored in bufdata.
469  */
470 static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
471 				  unsigned char data,
472 				  char *bufdata)
473 {
474 	/* Translatation table is not necessary, as global
475 	 * addr is the integer value of the GA# bits.
476 	 *
477 	 * NOTE: MSB is documented as zero, but I see it as '1' always....
478 	 *
479 	 * -----------------------------------------------
480 	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
481 	 * -----------------------------------------------
482 	 * GA0 - GA4	integer value of Global Address (backplane slot#)
483 	 * DEG			0 = cPCI Power supply output is starting to degrade
484 	 * 				1 = cPCI Power supply output is OK
485 	 * FAL			0 = cPCI Power supply has failed
486 	 * 				1 = cPCI Power supply output is OK
487 	 */
488 	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
489 	return 1;
490 }
491 
492 /* Function Description: Read standard voltage and power supply status.
493  * Return : Always 1 byte. Status stored in bufdata.
494  */
495 static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
496 						unsigned char data,
497 						char *bufdata)
498 {
499 	unsigned char tmp, ret = 0;
500 	int i, j = 0;
501 
502 	tmp = data & pchild->voltage_mask;
503 
504 	/* Two channels are used to monitor voltage and power supply. */
505 	if (tmp == pchild->voltage_mask) {
506 		/* All bits are on. Voltage and power supply are okay. */
507 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
508 	} else if (tmp == 0) {
509 		/* All bits are off. Voltage and power supply are bad */
510 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
511 	} else {
512 		/* Either voltage or power supply has problem. */
513 		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
514 			if (pchild->voltage_mask & chnls_mask[i]) {
515 				j++;
516 
517 				/* Break out when there is a mismatch. */
518 				if (!(chnls_mask[i] & tmp))
519 					break;
520 			}
521 		}
522 
523 		/* Make a wish that hardware will always use the
524 		 * first channel for voltage and the second for
525 		 * power supply.
526 		 */
527 		if (j == 1)
528 			ret = ENVCTRL_VOLTAGE_BAD;
529 		else
530 			ret = ENVCTRL_POWERSUPPLY_BAD;
531 	}
532 
533 	bufdata[0] = ret;
534 	return 1;
535 }
536 
537 /* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
538  * Return: Number of read bytes. 0 for error.
539  */
540 static ssize_t
541 envctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
542 {
543 	struct i2c_child_t *pchild;
544 	unsigned char data[10];
545 	int ret = 0;
546 
547 	/* Get the type of read as decided in ioctl() call.
548 	 * Find the appropriate i2c child.
549 	 * Get the data and put back to the user buffer.
550 	 */
551 
552 	switch ((int)(long)file->private_data) {
553 	case ENVCTRL_RD_WARNING_TEMPERATURE:
554 		if (warning_temperature == 0)
555 			return 0;
556 
557 		data[0] = (unsigned char)(warning_temperature);
558 		ret = 1;
559 		if (copy_to_user(buf, data, ret))
560 			ret = -EFAULT;
561 		break;
562 
563 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
564 		if (shutdown_temperature == 0)
565 			return 0;
566 
567 		data[0] = (unsigned char)(shutdown_temperature);
568 		ret = 1;
569 		if (copy_to_user(buf, data, ret))
570 			ret = -EFAULT;
571 		break;
572 
573 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
574 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
575 			return 0;
576 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
577 		if (copy_to_user(buf, data, ret))
578 			ret = -EFAULT;
579 		break;
580 
581 	case ENVCTRL_RD_CPU_TEMPERATURE:
582 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
583 			return 0;
584 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUTEMP_MON, data);
585 
586 		/* Reset cpu to the default cpu0. */
587 		if (copy_to_user(buf, data, ret))
588 			ret = -EFAULT;
589 		break;
590 
591 	case ENVCTRL_RD_CPU_VOLTAGE:
592 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
593 			return 0;
594 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUVOLTAGE_MON, data);
595 
596 		/* Reset cpu to the default cpu0. */
597 		if (copy_to_user(buf, data, ret))
598 			ret = -EFAULT;
599 		break;
600 
601 	case ENVCTRL_RD_SCSI_TEMPERATURE:
602 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
603 			return 0;
604 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
605 		if (copy_to_user(buf, data, ret))
606 			ret = -EFAULT;
607 		break;
608 
609 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
610 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
611 			return 0;
612 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
613 		if (copy_to_user(buf, data, ret))
614 			ret = -EFAULT;
615 		break;
616 
617 	case ENVCTRL_RD_FAN_STATUS:
618 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
619 			return 0;
620 		data[0] = envctrl_i2c_read_8574(pchild->addr);
621 		ret = envctrl_i2c_fan_status(pchild,data[0], data);
622 		if (copy_to_user(buf, data, ret))
623 			ret = -EFAULT;
624 		break;
625 
626 	case ENVCTRL_RD_GLOBALADDRESS:
627 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
628 			return 0;
629 		data[0] = envctrl_i2c_read_8574(pchild->addr);
630 		ret = envctrl_i2c_globaladdr(pchild, data[0], data);
631 		if (copy_to_user(buf, data, ret))
632 			ret = -EFAULT;
633 		break;
634 
635 	case ENVCTRL_RD_VOLTAGE_STATUS:
636 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
637 			/* If voltage monitor not present, check for CPCI equivalent */
638 			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
639 				return 0;
640 		data[0] = envctrl_i2c_read_8574(pchild->addr);
641 		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
642 		if (copy_to_user(buf, data, ret))
643 			ret = -EFAULT;
644 		break;
645 
646 	default:
647 		break;
648 
649 	};
650 
651 	return ret;
652 }
653 
654 /* Function Description: Command what to read.  Mapped to user ioctl().
655  * Return: Gives 0 for implemented commands, -EINVAL otherwise.
656  */
657 static int
658 envctrl_ioctl(struct inode *inode, struct file *file,
659 	      unsigned int cmd, unsigned long arg)
660 {
661 	char __user *infobuf;
662 
663 	switch (cmd) {
664 	case ENVCTRL_RD_WARNING_TEMPERATURE:
665 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
666 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
667 	case ENVCTRL_RD_FAN_STATUS:
668 	case ENVCTRL_RD_VOLTAGE_STATUS:
669 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
670 	case ENVCTRL_RD_SCSI_TEMPERATURE:
671 	case ENVCTRL_RD_GLOBALADDRESS:
672 		file->private_data = (void *)(long)cmd;
673 		break;
674 
675 	case ENVCTRL_RD_CPU_TEMPERATURE:
676 	case ENVCTRL_RD_CPU_VOLTAGE:
677 		/* Check to see if application passes in any cpu number,
678 		 * the default is cpu0.
679 		 */
680 		infobuf = (char __user *) arg;
681 		if (infobuf == NULL) {
682 			read_cpu = 0;
683 		}else {
684 			get_user(read_cpu, infobuf);
685 		}
686 
687 		/* Save the command for use when reading. */
688 		file->private_data = (void *)(long)cmd;
689 		break;
690 
691 	default:
692 		return -EINVAL;
693 	};
694 
695 	return 0;
696 }
697 
698 /* Function Description: open device. Mapped to user open().
699  * Return: Always 0.
700  */
701 static int
702 envctrl_open(struct inode *inode, struct file *file)
703 {
704 	file->private_data = NULL;
705 	return 0;
706 }
707 
708 /* Function Description: Open device. Mapped to user close().
709  * Return: Always 0.
710  */
711 static int
712 envctrl_release(struct inode *inode, struct file *file)
713 {
714 	return 0;
715 }
716 
717 static struct file_operations envctrl_fops = {
718 	.owner =	THIS_MODULE,
719 	.read =		envctrl_read,
720 	.ioctl =	envctrl_ioctl,
721 	.open =		envctrl_open,
722 	.release =	envctrl_release,
723 };
724 
725 static struct miscdevice envctrl_dev = {
726 	ENVCTRL_MINOR,
727 	"envctrl",
728 	&envctrl_fops
729 };
730 
731 /* Function Description: Set monitor type based on firmware description.
732  * Return: None.
733  */
734 static void envctrl_set_mon(struct i2c_child_t *pchild,
735 			    char *chnl_desc,
736 			    int chnl_no)
737 {
738 	/* Firmware only has temperature type.  It does not distinguish
739 	 * different kinds of temperatures.  We use channel description
740 	 * to disinguish them.
741 	 */
742 	if (!(strcmp(chnl_desc,"temp,cpu")) ||
743 	    !(strcmp(chnl_desc,"temp,cpu0")) ||
744 	    !(strcmp(chnl_desc,"temp,cpu1")) ||
745 	    !(strcmp(chnl_desc,"temp,cpu2")) ||
746 	    !(strcmp(chnl_desc,"temp,cpu3")))
747 		pchild->mon_type[chnl_no] = ENVCTRL_CPUTEMP_MON;
748 
749 	if (!(strcmp(chnl_desc,"vddcore,cpu0")) ||
750 	    !(strcmp(chnl_desc,"vddcore,cpu1")) ||
751 	    !(strcmp(chnl_desc,"vddcore,cpu2")) ||
752 	    !(strcmp(chnl_desc,"vddcore,cpu3")))
753 		pchild->mon_type[chnl_no] = ENVCTRL_CPUVOLTAGE_MON;
754 
755 	if (!(strcmp(chnl_desc,"temp,motherboard")))
756 		pchild->mon_type[chnl_no] = ENVCTRL_MTHRBDTEMP_MON;
757 
758 	if (!(strcmp(chnl_desc,"temp,scsi")))
759 		pchild->mon_type[chnl_no] = ENVCTRL_SCSITEMP_MON;
760 
761 	if (!(strcmp(chnl_desc,"temp,ethernet")))
762 		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
763 }
764 
765 /* Function Description: Initialize monitor channel with channel desc,
766  *                       decoding tables, monitor type, optional properties.
767  * Return: None.
768  */
769 static void envctrl_init_adc(struct i2c_child_t *pchild, int node)
770 {
771 	char chnls_desc[CHANNEL_DESC_SZ];
772 	int i = 0, len;
773 	char *pos = chnls_desc;
774 
775 	/* Firmware describe channels into a stream separated by a '\0'. */
776 	len = prom_getproperty(node, "channels-description", chnls_desc,
777 			       CHANNEL_DESC_SZ);
778 	chnls_desc[CHANNEL_DESC_SZ - 1] = '\0';
779 
780 	while (len > 0) {
781 		int l = strlen(pos) + 1;
782 		envctrl_set_mon(pchild, pos, i++);
783 		len -= l;
784 		pos += l;
785 	}
786 
787 	/* Get optional properties. */
788         len = prom_getproperty(node, "warning-temp", (char *)&warning_temperature,
789 			       sizeof(warning_temperature));
790         len = prom_getproperty(node, "shutdown-temp", (char *)&shutdown_temperature,
791 			       sizeof(shutdown_temperature));
792 }
793 
794 /* Function Description: Initialize child device monitoring fan status.
795  * Return: None.
796  */
797 static void envctrl_init_fanstat(struct i2c_child_t *pchild)
798 {
799 	int i;
800 
801 	/* Go through all channels and set up the mask. */
802 	for (i = 0; i < pchild->total_chnls; i++)
803 		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
804 
805 	/* We only need to know if this child has fan status monitored.
806 	 * We don't care which channels since we have the mask already.
807 	 */
808 	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
809 }
810 
811 /* Function Description: Initialize child device for global addressing line.
812  * Return: None.
813  */
814 static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
815 {
816 	int i;
817 
818 	/* Voltage/PowerSupply monitoring is piggybacked
819 	 * with Global Address on CompactPCI.  See comments
820 	 * within envctrl_i2c_globaladdr for bit assignments.
821 	 *
822 	 * The mask is created here by assigning mask bits to each
823 	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
824 	 * Channel numbers are not consecutive within the globaladdr
825 	 * node (why?), so we use the actual counter value as chnls_mask
826 	 * index instead of the chnl_array[x].chnl_no value.
827 	 *
828 	 * NOTE: This loop could be replaced with a constant representing
829 	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
830 	 */
831 	for (i = 0; i < pchild->total_chnls; i++) {
832 		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
833 			pchild->voltage_mask |= chnls_mask[i];
834 		}
835 	}
836 
837 	/* We only need to know if this child has global addressing
838 	 * line monitored.  We don't care which channels since we know
839 	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
840 	 */
841 	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
842 }
843 
844 /* Initialize child device monitoring voltage status. */
845 static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
846 {
847 	int i;
848 
849 	/* Go through all channels and set up the mask. */
850 	for (i = 0; i < pchild->total_chnls; i++)
851 		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
852 
853 	/* We only need to know if this child has voltage status monitored.
854 	 * We don't care which channels since we have the mask already.
855 	 */
856 	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
857 }
858 
859 /* Function Description: Initialize i2c child device.
860  * Return: None.
861  */
862 static void envctrl_init_i2c_child(struct linux_ebus_child *edev_child,
863 				   struct i2c_child_t *pchild)
864 {
865 	int node, len, i, tbls_size = 0;
866 
867 	node = edev_child->prom_node;
868 
869 	/* Get device address. */
870 	len = prom_getproperty(node, "reg",
871 			       (char *) &(pchild->addr),
872 			       sizeof(pchild->addr));
873 
874 	/* Get tables property.  Read firmware temperature tables. */
875 	len = prom_getproperty(node, "translation",
876 			       (char *) pchild->tblprop_array,
877 			       (PCF8584_MAX_CHANNELS *
878 				sizeof(struct pcf8584_tblprop)));
879 	if (len > 0) {
880                 pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
881 		for (i = 0; i < pchild->total_tbls; i++) {
882 			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
883 				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
884 			}
885 		}
886 
887                 pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
888 		if (pchild->tables == NULL){
889 			printk("envctrl: Failed to allocate table.\n");
890 			return;
891 		}
892                 len = prom_getproperty(node, "tables",
893 				       (char *) pchild->tables, tbls_size);
894                 if (len <= 0) {
895 			printk("envctrl: Failed to get table.\n");
896 			return;
897 		}
898 	}
899 
900 	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
901 	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
902 	 * "For Factory Use Only."
903 	 *
904 	 * We ignore the node on these platforms by assigning the
905 	 * 'NULL' monitor type.
906 	 */
907 	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
908 		int len;
909 		char prop[56];
910 
911 		len = prom_getproperty(prom_root_node, "name", prop, sizeof(prop));
912 		if (0 < len && (0 == strncmp(prop, "SUNW,UltraSPARC-IIi-cEngine", len)))
913 		{
914 			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
915 				pchild->mon_type[len] = ENVCTRL_NOMON;
916 			}
917 			return;
918 		}
919 	}
920 
921 	/* Get the monitor channels. */
922 	len = prom_getproperty(node, "channels-in-use",
923 			       (char *) pchild->chnl_array,
924 			       (PCF8584_MAX_CHANNELS *
925 				sizeof(struct pcf8584_channel)));
926 	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
927 
928 	for (i = 0; i < pchild->total_chnls; i++) {
929 		switch (pchild->chnl_array[i].type) {
930 		case PCF8584_TEMP_TYPE:
931 			envctrl_init_adc(pchild, node);
932 			break;
933 
934 		case PCF8584_GLOBALADDR_TYPE:
935 			envctrl_init_globaladdr(pchild);
936 			i = pchild->total_chnls;
937 			break;
938 
939 		case PCF8584_FANSTAT_TYPE:
940 			envctrl_init_fanstat(pchild);
941 			i = pchild->total_chnls;
942 			break;
943 
944 		case PCF8584_VOLTAGE_TYPE:
945 			if (pchild->i2ctype == I2C_ADC) {
946 				envctrl_init_adc(pchild,node);
947 			} else {
948 				envctrl_init_voltage_status(pchild);
949 			}
950 			i = pchild->total_chnls;
951 			break;
952 
953 		default:
954 			break;
955 		};
956 	}
957 }
958 
959 /* Function Description: Search the child device list for a device.
960  * Return : The i2c child if found. NULL otherwise.
961  */
962 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
963 {
964 	int i, j;
965 
966 	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
967 		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
968 			if (i2c_childlist[i].mon_type[j] == mon_type) {
969 				return (struct i2c_child_t *)(&(i2c_childlist[i]));
970 			}
971 		}
972 	}
973 	return NULL;
974 }
975 
976 static void envctrl_do_shutdown(void)
977 {
978 	static int inprog = 0;
979 	static char *envp[] = {
980 		"HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
981 	char *argv[] = {
982 		"/sbin/shutdown", "-h", "now", NULL };
983 
984 	if (inprog != 0)
985 		return;
986 
987 	inprog = 1;
988 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
989 	if (0 > execve("/sbin/shutdown", argv, envp)) {
990 		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n");
991 		inprog = 0;  /* unlikely to succeed, but we could try again */
992 	}
993 }
994 
995 static struct task_struct *kenvctrld_task;
996 
997 static int kenvctrld(void *__unused)
998 {
999 	int poll_interval;
1000 	int whichcpu;
1001 	char tempbuf[10];
1002 	struct i2c_child_t *cputemp;
1003 
1004 	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
1005 		printk(KERN_ERR
1006 		       "envctrl: kenvctrld unable to monitor CPU temp-- exiting\n");
1007 		return -ENODEV;
1008 	}
1009 
1010 	poll_interval = 5 * HZ; /* TODO env_mon_interval */
1011 
1012 	daemonize("kenvctrld");
1013 	allow_signal(SIGKILL);
1014 
1015 	kenvctrld_task = current;
1016 
1017 	printk(KERN_INFO "envctrl: %s starting...\n", current->comm);
1018 	for (;;) {
1019 		current->state = TASK_INTERRUPTIBLE;
1020 		schedule_timeout(poll_interval);
1021 
1022 		if(signal_pending(current))
1023 			break;
1024 
1025 		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
1026 			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
1027 						      ENVCTRL_CPUTEMP_MON,
1028 						      tempbuf)) {
1029 				if (tempbuf[0] >= shutdown_temperature) {
1030 					printk(KERN_CRIT
1031 						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
1032 						"shutdown threshold %i C\n",
1033 						current->comm, whichcpu,
1034 						tempbuf[0], shutdown_temperature);
1035 					envctrl_do_shutdown();
1036 				}
1037 			}
1038 		}
1039 	}
1040 	printk(KERN_INFO "envctrl: %s exiting...\n", current->comm);
1041 	return 0;
1042 }
1043 
1044 static int __init envctrl_init(void)
1045 {
1046 #ifdef CONFIG_PCI
1047 	struct linux_ebus *ebus = NULL;
1048 	struct linux_ebus_device *edev = NULL;
1049 	struct linux_ebus_child *edev_child = NULL;
1050 	int err, i = 0;
1051 
1052 	for_each_ebus(ebus) {
1053 		for_each_ebusdev(edev, ebus) {
1054 			if (!strcmp(edev->prom_name, "bbc")) {
1055 				/* If we find a boot-bus controller node,
1056 				 * then this envctrl driver is not for us.
1057 				 */
1058 				return -ENODEV;
1059 			}
1060 		}
1061 	}
1062 
1063 	/* Traverse through ebus and ebus device list for i2c device and
1064 	 * adc and gpio nodes.
1065 	 */
1066 	for_each_ebus(ebus) {
1067 		for_each_ebusdev(edev, ebus) {
1068 			if (!strcmp(edev->prom_name, "i2c")) {
1069 				i2c = ioremap(edev->resource[0].start, 0x2);
1070 				for_each_edevchild(edev, edev_child) {
1071 					if (!strcmp("gpio", edev_child->prom_name)) {
1072 						i2c_childlist[i].i2ctype = I2C_GPIO;
1073 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1074 					}
1075 					if (!strcmp("adc", edev_child->prom_name)) {
1076 						i2c_childlist[i].i2ctype = I2C_ADC;
1077 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1078 					}
1079 				}
1080 				goto done;
1081 			}
1082 		}
1083 	}
1084 
1085 done:
1086 	if (!edev) {
1087 		printk("envctrl: I2C device not found.\n");
1088 		return -ENODEV;
1089 	}
1090 
1091 	/* Set device address. */
1092 	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
1093 	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
1094 
1095 	/* Set system clock and SCL frequencies. */
1096 	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
1097 	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
1098 
1099 	/* Enable serial interface. */
1100 	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
1101 	udelay(200);
1102 
1103 	/* Register the device as a minor miscellaneous device. */
1104 	err = misc_register(&envctrl_dev);
1105 	if (err) {
1106 		printk("envctrl: Unable to get misc minor %d\n",
1107 		       envctrl_dev.minor);
1108 		goto out_iounmap;
1109 	}
1110 
1111 	/* Note above traversal routine post-incremented 'i' to accommodate
1112 	 * a next child device, so we decrement before reverse-traversal of
1113 	 * child devices.
1114 	 */
1115 	printk("envctrl: initialized ");
1116 	for (--i; i >= 0; --i) {
1117 		printk("[%s 0x%lx]%s",
1118 			(I2C_ADC == i2c_childlist[i].i2ctype) ? ("adc") :
1119 			((I2C_GPIO == i2c_childlist[i].i2ctype) ? ("gpio") : ("unknown")),
1120 			i2c_childlist[i].addr, (0 == i) ? ("\n") : (" "));
1121 	}
1122 
1123 	err = kernel_thread(kenvctrld, NULL, CLONE_FS | CLONE_FILES);
1124 	if (err < 0)
1125 		goto out_deregister;
1126 
1127 	return 0;
1128 
1129 out_deregister:
1130 	misc_deregister(&envctrl_dev);
1131 out_iounmap:
1132 	iounmap(i2c);
1133 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++) {
1134 		if (i2c_childlist[i].tables)
1135 			kfree(i2c_childlist[i].tables);
1136 	}
1137 	return err;
1138 #else
1139 	return -ENODEV;
1140 #endif
1141 }
1142 
1143 static void __exit envctrl_cleanup(void)
1144 {
1145 	int i;
1146 
1147 	if (NULL != kenvctrld_task) {
1148 		force_sig(SIGKILL, kenvctrld_task);
1149 		for (;;) {
1150 			struct task_struct *p;
1151 			int found = 0;
1152 
1153 			read_lock(&tasklist_lock);
1154 			for_each_process(p) {
1155 				if (p == kenvctrld_task) {
1156 					found = 1;
1157 					break;
1158 				}
1159 			}
1160 			read_unlock(&tasklist_lock);
1161 
1162 			if (!found)
1163 				break;
1164 
1165 			msleep(1000);
1166 		}
1167 		kenvctrld_task = NULL;
1168 	}
1169 
1170 	iounmap(i2c);
1171 	misc_deregister(&envctrl_dev);
1172 
1173 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++) {
1174 		if (i2c_childlist[i].tables)
1175 			kfree(i2c_childlist[i].tables);
1176 	}
1177 }
1178 
1179 module_init(envctrl_init);
1180 module_exit(envctrl_cleanup);
1181 MODULE_LICENSE("GPL");
1182