xref: /linux/drivers/sbus/char/envctrl.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 #define __KERNEL_SYSCALLS__
23 static int errno;
24 
25 #include <linux/config.h>
26 #include <linux/module.h>
27 #include <linux/sched.h>
28 #include <linux/kthread.h>
29 #include <linux/errno.h>
30 #include <linux/delay.h>
31 #include <linux/ioport.h>
32 #include <linux/init.h>
33 #include <linux/miscdevice.h>
34 #include <linux/mm.h>
35 #include <linux/slab.h>
36 #include <linux/kernel.h>
37 
38 #include <asm/ebus.h>
39 #include <asm/uaccess.h>
40 #include <asm/envctrl.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 long
658 envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
659 {
660 	char __user *infobuf;
661 
662 	switch (cmd) {
663 	case ENVCTRL_RD_WARNING_TEMPERATURE:
664 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
665 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
666 	case ENVCTRL_RD_FAN_STATUS:
667 	case ENVCTRL_RD_VOLTAGE_STATUS:
668 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
669 	case ENVCTRL_RD_SCSI_TEMPERATURE:
670 	case ENVCTRL_RD_GLOBALADDRESS:
671 		file->private_data = (void *)(long)cmd;
672 		break;
673 
674 	case ENVCTRL_RD_CPU_TEMPERATURE:
675 	case ENVCTRL_RD_CPU_VOLTAGE:
676 		/* Check to see if application passes in any cpu number,
677 		 * the default is cpu0.
678 		 */
679 		infobuf = (char __user *) arg;
680 		if (infobuf == NULL) {
681 			read_cpu = 0;
682 		}else {
683 			get_user(read_cpu, infobuf);
684 		}
685 
686 		/* Save the command for use when reading. */
687 		file->private_data = (void *)(long)cmd;
688 		break;
689 
690 	default:
691 		return -EINVAL;
692 	};
693 
694 	return 0;
695 }
696 
697 /* Function Description: open device. Mapped to user open().
698  * Return: Always 0.
699  */
700 static int
701 envctrl_open(struct inode *inode, struct file *file)
702 {
703 	file->private_data = NULL;
704 	return 0;
705 }
706 
707 /* Function Description: Open device. Mapped to user close().
708  * Return: Always 0.
709  */
710 static int
711 envctrl_release(struct inode *inode, struct file *file)
712 {
713 	return 0;
714 }
715 
716 static struct file_operations envctrl_fops = {
717 	.owner =		THIS_MODULE,
718 	.read =			envctrl_read,
719 	.unlocked_ioctl =	envctrl_ioctl,
720 #ifdef CONFIG_COMPAT
721 	.compat_ioctl =		envctrl_ioctl,
722 #endif
723 	.open =			envctrl_open,
724 	.release =		envctrl_release,
725 };
726 
727 static struct miscdevice envctrl_dev = {
728 	ENVCTRL_MINOR,
729 	"envctrl",
730 	&envctrl_fops
731 };
732 
733 /* Function Description: Set monitor type based on firmware description.
734  * Return: None.
735  */
736 static void envctrl_set_mon(struct i2c_child_t *pchild,
737 			    char *chnl_desc,
738 			    int chnl_no)
739 {
740 	/* Firmware only has temperature type.  It does not distinguish
741 	 * different kinds of temperatures.  We use channel description
742 	 * to disinguish them.
743 	 */
744 	if (!(strcmp(chnl_desc,"temp,cpu")) ||
745 	    !(strcmp(chnl_desc,"temp,cpu0")) ||
746 	    !(strcmp(chnl_desc,"temp,cpu1")) ||
747 	    !(strcmp(chnl_desc,"temp,cpu2")) ||
748 	    !(strcmp(chnl_desc,"temp,cpu3")))
749 		pchild->mon_type[chnl_no] = ENVCTRL_CPUTEMP_MON;
750 
751 	if (!(strcmp(chnl_desc,"vddcore,cpu0")) ||
752 	    !(strcmp(chnl_desc,"vddcore,cpu1")) ||
753 	    !(strcmp(chnl_desc,"vddcore,cpu2")) ||
754 	    !(strcmp(chnl_desc,"vddcore,cpu3")))
755 		pchild->mon_type[chnl_no] = ENVCTRL_CPUVOLTAGE_MON;
756 
757 	if (!(strcmp(chnl_desc,"temp,motherboard")))
758 		pchild->mon_type[chnl_no] = ENVCTRL_MTHRBDTEMP_MON;
759 
760 	if (!(strcmp(chnl_desc,"temp,scsi")))
761 		pchild->mon_type[chnl_no] = ENVCTRL_SCSITEMP_MON;
762 
763 	if (!(strcmp(chnl_desc,"temp,ethernet")))
764 		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
765 }
766 
767 /* Function Description: Initialize monitor channel with channel desc,
768  *                       decoding tables, monitor type, optional properties.
769  * Return: None.
770  */
771 static void envctrl_init_adc(struct i2c_child_t *pchild, int node)
772 {
773 	char chnls_desc[CHANNEL_DESC_SZ];
774 	int i = 0, len;
775 	char *pos = chnls_desc;
776 
777 	/* Firmware describe channels into a stream separated by a '\0'. */
778 	len = prom_getproperty(node, "channels-description", chnls_desc,
779 			       CHANNEL_DESC_SZ);
780 	chnls_desc[CHANNEL_DESC_SZ - 1] = '\0';
781 
782 	while (len > 0) {
783 		int l = strlen(pos) + 1;
784 		envctrl_set_mon(pchild, pos, i++);
785 		len -= l;
786 		pos += l;
787 	}
788 
789 	/* Get optional properties. */
790         len = prom_getproperty(node, "warning-temp", (char *)&warning_temperature,
791 			       sizeof(warning_temperature));
792         len = prom_getproperty(node, "shutdown-temp", (char *)&shutdown_temperature,
793 			       sizeof(shutdown_temperature));
794 }
795 
796 /* Function Description: Initialize child device monitoring fan status.
797  * Return: None.
798  */
799 static void envctrl_init_fanstat(struct i2c_child_t *pchild)
800 {
801 	int i;
802 
803 	/* Go through all channels and set up the mask. */
804 	for (i = 0; i < pchild->total_chnls; i++)
805 		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
806 
807 	/* We only need to know if this child has fan status monitored.
808 	 * We don't care which channels since we have the mask already.
809 	 */
810 	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
811 }
812 
813 /* Function Description: Initialize child device for global addressing line.
814  * Return: None.
815  */
816 static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
817 {
818 	int i;
819 
820 	/* Voltage/PowerSupply monitoring is piggybacked
821 	 * with Global Address on CompactPCI.  See comments
822 	 * within envctrl_i2c_globaladdr for bit assignments.
823 	 *
824 	 * The mask is created here by assigning mask bits to each
825 	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
826 	 * Channel numbers are not consecutive within the globaladdr
827 	 * node (why?), so we use the actual counter value as chnls_mask
828 	 * index instead of the chnl_array[x].chnl_no value.
829 	 *
830 	 * NOTE: This loop could be replaced with a constant representing
831 	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
832 	 */
833 	for (i = 0; i < pchild->total_chnls; i++) {
834 		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
835 			pchild->voltage_mask |= chnls_mask[i];
836 		}
837 	}
838 
839 	/* We only need to know if this child has global addressing
840 	 * line monitored.  We don't care which channels since we know
841 	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
842 	 */
843 	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
844 }
845 
846 /* Initialize child device monitoring voltage status. */
847 static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
848 {
849 	int i;
850 
851 	/* Go through all channels and set up the mask. */
852 	for (i = 0; i < pchild->total_chnls; i++)
853 		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
854 
855 	/* We only need to know if this child has voltage status monitored.
856 	 * We don't care which channels since we have the mask already.
857 	 */
858 	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
859 }
860 
861 /* Function Description: Initialize i2c child device.
862  * Return: None.
863  */
864 static void envctrl_init_i2c_child(struct linux_ebus_child *edev_child,
865 				   struct i2c_child_t *pchild)
866 {
867 	int node, len, i, tbls_size = 0;
868 
869 	node = edev_child->prom_node;
870 
871 	/* Get device address. */
872 	len = prom_getproperty(node, "reg",
873 			       (char *) &(pchild->addr),
874 			       sizeof(pchild->addr));
875 
876 	/* Get tables property.  Read firmware temperature tables. */
877 	len = prom_getproperty(node, "translation",
878 			       (char *) pchild->tblprop_array,
879 			       (PCF8584_MAX_CHANNELS *
880 				sizeof(struct pcf8584_tblprop)));
881 	if (len > 0) {
882                 pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
883 		for (i = 0; i < pchild->total_tbls; i++) {
884 			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
885 				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
886 			}
887 		}
888 
889                 pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
890 		if (pchild->tables == NULL){
891 			printk("envctrl: Failed to allocate table.\n");
892 			return;
893 		}
894                 len = prom_getproperty(node, "tables",
895 				       (char *) pchild->tables, tbls_size);
896                 if (len <= 0) {
897 			printk("envctrl: Failed to get table.\n");
898 			return;
899 		}
900 	}
901 
902 	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
903 	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
904 	 * "For Factory Use Only."
905 	 *
906 	 * We ignore the node on these platforms by assigning the
907 	 * 'NULL' monitor type.
908 	 */
909 	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
910 		int len;
911 		char prop[56];
912 
913 		len = prom_getproperty(prom_root_node, "name", prop, sizeof(prop));
914 		if (0 < len && (0 == strncmp(prop, "SUNW,UltraSPARC-IIi-cEngine", len)))
915 		{
916 			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
917 				pchild->mon_type[len] = ENVCTRL_NOMON;
918 			}
919 			return;
920 		}
921 	}
922 
923 	/* Get the monitor channels. */
924 	len = prom_getproperty(node, "channels-in-use",
925 			       (char *) pchild->chnl_array,
926 			       (PCF8584_MAX_CHANNELS *
927 				sizeof(struct pcf8584_channel)));
928 	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
929 
930 	for (i = 0; i < pchild->total_chnls; i++) {
931 		switch (pchild->chnl_array[i].type) {
932 		case PCF8584_TEMP_TYPE:
933 			envctrl_init_adc(pchild, node);
934 			break;
935 
936 		case PCF8584_GLOBALADDR_TYPE:
937 			envctrl_init_globaladdr(pchild);
938 			i = pchild->total_chnls;
939 			break;
940 
941 		case PCF8584_FANSTAT_TYPE:
942 			envctrl_init_fanstat(pchild);
943 			i = pchild->total_chnls;
944 			break;
945 
946 		case PCF8584_VOLTAGE_TYPE:
947 			if (pchild->i2ctype == I2C_ADC) {
948 				envctrl_init_adc(pchild,node);
949 			} else {
950 				envctrl_init_voltage_status(pchild);
951 			}
952 			i = pchild->total_chnls;
953 			break;
954 
955 		default:
956 			break;
957 		};
958 	}
959 }
960 
961 /* Function Description: Search the child device list for a device.
962  * Return : The i2c child if found. NULL otherwise.
963  */
964 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
965 {
966 	int i, j;
967 
968 	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
969 		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
970 			if (i2c_childlist[i].mon_type[j] == mon_type) {
971 				return (struct i2c_child_t *)(&(i2c_childlist[i]));
972 			}
973 		}
974 	}
975 	return NULL;
976 }
977 
978 static void envctrl_do_shutdown(void)
979 {
980 	static int inprog = 0;
981 	static char *envp[] = {
982 		"HOME=/", "TERM=linux", "PATH=/sbin:/usr/sbin:/bin:/usr/bin", NULL };
983 	char *argv[] = {
984 		"/sbin/shutdown", "-h", "now", NULL };
985 
986 	if (inprog != 0)
987 		return;
988 
989 	inprog = 1;
990 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
991 	if (0 > execve("/sbin/shutdown", argv, envp)) {
992 		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n");
993 		inprog = 0;  /* unlikely to succeed, but we could try again */
994 	}
995 }
996 
997 static struct task_struct *kenvctrld_task;
998 
999 static int kenvctrld(void *__unused)
1000 {
1001 	int poll_interval;
1002 	int whichcpu;
1003 	char tempbuf[10];
1004 	struct i2c_child_t *cputemp;
1005 
1006 	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
1007 		printk(KERN_ERR
1008 		       "envctrl: kenvctrld unable to monitor CPU temp-- exiting\n");
1009 		return -ENODEV;
1010 	}
1011 
1012 	poll_interval = 5000; /* TODO env_mon_interval */
1013 
1014 	printk(KERN_INFO "envctrl: %s starting...\n", current->comm);
1015 	for (;;) {
1016 		msleep_interruptible(poll_interval);
1017 
1018 		if (kthread_should_stop())
1019 			break;
1020 
1021 		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
1022 			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
1023 						      ENVCTRL_CPUTEMP_MON,
1024 						      tempbuf)) {
1025 				if (tempbuf[0] >= shutdown_temperature) {
1026 					printk(KERN_CRIT
1027 						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
1028 						"shutdown threshold %i C\n",
1029 						current->comm, whichcpu,
1030 						tempbuf[0], shutdown_temperature);
1031 					envctrl_do_shutdown();
1032 				}
1033 			}
1034 		}
1035 	}
1036 	printk(KERN_INFO "envctrl: %s exiting...\n", current->comm);
1037 	return 0;
1038 }
1039 
1040 static int __init envctrl_init(void)
1041 {
1042 	struct linux_ebus *ebus = NULL;
1043 	struct linux_ebus_device *edev = NULL;
1044 	struct linux_ebus_child *edev_child = NULL;
1045 	int err, i = 0;
1046 
1047 	for_each_ebus(ebus) {
1048 		for_each_ebusdev(edev, ebus) {
1049 			if (!strcmp(edev->prom_name, "bbc")) {
1050 				/* If we find a boot-bus controller node,
1051 				 * then this envctrl driver is not for us.
1052 				 */
1053 				return -ENODEV;
1054 			}
1055 		}
1056 	}
1057 
1058 	/* Traverse through ebus and ebus device list for i2c device and
1059 	 * adc and gpio nodes.
1060 	 */
1061 	for_each_ebus(ebus) {
1062 		for_each_ebusdev(edev, ebus) {
1063 			if (!strcmp(edev->prom_name, "i2c")) {
1064 				i2c = ioremap(edev->resource[0].start, 0x2);
1065 				for_each_edevchild(edev, edev_child) {
1066 					if (!strcmp("gpio", edev_child->prom_name)) {
1067 						i2c_childlist[i].i2ctype = I2C_GPIO;
1068 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1069 					}
1070 					if (!strcmp("adc", edev_child->prom_name)) {
1071 						i2c_childlist[i].i2ctype = I2C_ADC;
1072 						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
1073 					}
1074 				}
1075 				goto done;
1076 			}
1077 		}
1078 	}
1079 
1080 done:
1081 	if (!edev) {
1082 		printk("envctrl: I2C device not found.\n");
1083 		return -ENODEV;
1084 	}
1085 
1086 	/* Set device address. */
1087 	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
1088 	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
1089 
1090 	/* Set system clock and SCL frequencies. */
1091 	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
1092 	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
1093 
1094 	/* Enable serial interface. */
1095 	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
1096 	udelay(200);
1097 
1098 	/* Register the device as a minor miscellaneous device. */
1099 	err = misc_register(&envctrl_dev);
1100 	if (err) {
1101 		printk("envctrl: Unable to get misc minor %d\n",
1102 		       envctrl_dev.minor);
1103 		goto out_iounmap;
1104 	}
1105 
1106 	/* Note above traversal routine post-incremented 'i' to accommodate
1107 	 * a next child device, so we decrement before reverse-traversal of
1108 	 * child devices.
1109 	 */
1110 	printk("envctrl: initialized ");
1111 	for (--i; i >= 0; --i) {
1112 		printk("[%s 0x%lx]%s",
1113 			(I2C_ADC == i2c_childlist[i].i2ctype) ? ("adc") :
1114 			((I2C_GPIO == i2c_childlist[i].i2ctype) ? ("gpio") : ("unknown")),
1115 			i2c_childlist[i].addr, (0 == i) ? ("\n") : (" "));
1116 	}
1117 
1118 	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
1119 	if (IS_ERR(kenvctrld_task)) {
1120 		err = PTR_ERR(kenvctrld_task);
1121 		goto out_deregister;
1122 	}
1123 
1124 	return 0;
1125 
1126 out_deregister:
1127 	misc_deregister(&envctrl_dev);
1128 out_iounmap:
1129 	iounmap(i2c);
1130 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1131 		kfree(i2c_childlist[i].tables);
1132 
1133 	return err;
1134 }
1135 
1136 static void __exit envctrl_cleanup(void)
1137 {
1138 	int i;
1139 
1140 	kthread_stop(kenvctrld_task);
1141 
1142 	iounmap(i2c);
1143 	misc_deregister(&envctrl_dev);
1144 
1145 	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++)
1146 		kfree(i2c_childlist[i].tables);
1147 }
1148 
1149 module_init(envctrl_init);
1150 module_exit(envctrl_cleanup);
1151 MODULE_LICENSE("GPL");
1152