xref: /linux/drivers/sbus/char/envctrl.c (revision a33f32244d8550da8b4a26e277ce07d5c6d158b5)
1 /* envctrl.c: Temperature and Fan monitoring on Machines providing it.
2  *
3  * Copyright (C) 1998  Eddie C. Dost  (ecd@skynet.be)
4  * Copyright (C) 2000  Vinh Truong    (vinh.truong@eng.sun.com)
5  * VT - The implementation is to support Sun Microelectronics (SME) platform
6  *      environment monitoring.  SME platforms use pcf8584 as the i2c bus
7  *      controller to access pcf8591 (8-bit A/D and D/A converter) and
8  *      pcf8571 (256 x 8-bit static low-voltage RAM with I2C-bus interface).
9  *      At board level, it follows SME Firmware I2C Specification. Reference:
10  * 	http://www-eu2.semiconductors.com/pip/PCF8584P
11  * 	http://www-eu2.semiconductors.com/pip/PCF8574AP
12  * 	http://www-eu2.semiconductors.com/pip/PCF8591P
13  *
14  * EB - Added support for CP1500 Global Address and PS/Voltage monitoring.
15  * 		Eric Brower <ebrower@usa.net>
16  *
17  * DB - Audit every copy_to_user in envctrl_read.
18  *              Daniele Bellucci <bellucda@tiscali.it>
19  */
20 
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/kthread.h>
24 #include <linux/delay.h>
25 #include <linux/ioport.h>
26 #include <linux/miscdevice.h>
27 #include <linux/kmod.h>
28 #include <linux/reboot.h>
29 #include <linux/slab.h>
30 #include <linux/smp_lock.h>
31 #include <linux/of.h>
32 #include <linux/of_device.h>
33 
34 #include <asm/uaccess.h>
35 #include <asm/envctrl.h>
36 #include <asm/io.h>
37 
38 #define DRIVER_NAME	"envctrl"
39 #define PFX		DRIVER_NAME ": "
40 
41 #define ENVCTRL_MINOR	162
42 
43 #define PCF8584_ADDRESS	0x55
44 
45 #define CONTROL_PIN	0x80
46 #define CONTROL_ES0	0x40
47 #define CONTROL_ES1	0x20
48 #define CONTROL_ES2	0x10
49 #define CONTROL_ENI	0x08
50 #define CONTROL_STA	0x04
51 #define CONTROL_STO	0x02
52 #define CONTROL_ACK	0x01
53 
54 #define STATUS_PIN	0x80
55 #define STATUS_STS	0x20
56 #define STATUS_BER	0x10
57 #define STATUS_LRB	0x08
58 #define STATUS_AD0	0x08
59 #define STATUS_AAB	0x04
60 #define STATUS_LAB	0x02
61 #define STATUS_BB	0x01
62 
63 /*
64  * CLK Mode Register.
65  */
66 #define BUS_CLK_90	0x00
67 #define BUS_CLK_45	0x01
68 #define BUS_CLK_11	0x02
69 #define BUS_CLK_1_5	0x03
70 
71 #define CLK_3		0x00
72 #define CLK_4_43	0x10
73 #define CLK_6		0x14
74 #define CLK_8		0x18
75 #define CLK_12		0x1c
76 
77 #define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
78 #define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */
79 
80 /* Monitor type of i2c child device.
81  * Firmware definitions.
82  */
83 #define PCF8584_MAX_CHANNELS            8
84 #define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
85 #define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
86 #define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
87 #define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/
88 
89 /* Monitor type of i2c child device.
90  * Driver definitions.
91  */
92 #define ENVCTRL_NOMON				0
93 #define ENVCTRL_CPUTEMP_MON			1    /* cpu temperature monitor */
94 #define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
95 #define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
96 #define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperature */
97 					     /* monitor                     */
98 #define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
99 #define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
100 #define ENVCTRL_SCSITEMP_MON		7    /* scsi temperature */
101 #define ENVCTRL_GLOBALADDR_MON		8    /* global address */
102 
103 /* Child device type.
104  * Driver definitions.
105  */
106 #define I2C_ADC				0    /* pcf8591 */
107 #define I2C_GPIO			1    /* pcf8571 */
108 
109 /* Data read from child device may need to decode
110  * through a data table and a scale.
111  * Translation type as defined by firmware.
112  */
113 #define ENVCTRL_TRANSLATE_NO		0
114 #define ENVCTRL_TRANSLATE_PARTIAL	1
115 #define ENVCTRL_TRANSLATE_COMBINED	2
116 #define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
117 #define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */
118 
119 /* Driver miscellaneous definitions. */
120 #define ENVCTRL_MAX_CPU			4
121 #define CHANNEL_DESC_SZ			256
122 
123 /* Mask values for combined GlobalAddress/PowerStatus node */
124 #define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
125 #define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60
126 
127 /* Node 0x70 ignored on CompactPCI CP1400/1500 platforms
128  * (see envctrl_init_i2c_child)
129  */
130 #define ENVCTRL_CPCI_IGNORED_NODE		0x70
131 
132 #define PCF8584_DATA	0x00
133 #define PCF8584_CSR	0x01
134 
135 /* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
136  * Property of a port or channel as defined by the firmware.
137  */
138 struct pcf8584_channel {
139         unsigned char chnl_no;
140         unsigned char io_direction;
141         unsigned char type;
142         unsigned char last;
143 };
144 
145 /* Each child device may have one or more tables of bytes to help decode
146  * data. Table property as defined by the firmware.
147  */
148 struct pcf8584_tblprop {
149         unsigned int type;
150         unsigned int scale;
151         unsigned int offset; /* offset from the beginning of the table */
152         unsigned int size;
153 };
154 
155 /* i2c child */
156 struct i2c_child_t {
157 	/* Either ADC or GPIO. */
158 	unsigned char i2ctype;
159         unsigned long addr;
160         struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];
161 
162 	/* Channel info. */
163 	unsigned int total_chnls;	/* Number of monitor channels. */
164 	unsigned char fan_mask;		/* Byte mask for fan status channels. */
165 	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
166         struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];
167 
168 	/* Properties of all monitor channels. */
169 	unsigned int total_tbls;	/* Number of monitor tables. */
170         char *tables;			/* Pointer to table(s). */
171 	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
172 	char mon_type[PCF8584_MAX_CHANNELS];
173 };
174 
175 static void __iomem *i2c;
176 static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
177 static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
178 static unsigned int warning_temperature = 0;
179 static unsigned int shutdown_temperature = 0;
180 static char read_cpu;
181 
182 /* Forward declarations. */
183 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);
184 
185 /* Function Description: Test the PIN bit (Pending Interrupt Not)
186  * 			 to test when serial transmission is completed .
187  * Return : None.
188  */
189 static void envtrl_i2c_test_pin(void)
190 {
191 	int limit = 1000000;
192 
193 	while (--limit > 0) {
194 		if (!(readb(i2c + PCF8584_CSR) & STATUS_PIN))
195 			break;
196 		udelay(1);
197 	}
198 
199 	if (limit <= 0)
200 		printk(KERN_INFO PFX "Pin status will not clear.\n");
201 }
202 
203 /* Function Description: Test busy bit.
204  * Return : None.
205  */
206 static void envctrl_i2c_test_bb(void)
207 {
208 	int limit = 1000000;
209 
210 	while (--limit > 0) {
211 		/* Busy bit 0 means busy. */
212 		if (readb(i2c + PCF8584_CSR) & STATUS_BB)
213 			break;
214 		udelay(1);
215 	}
216 
217 	if (limit <= 0)
218 		printk(KERN_INFO PFX "Busy bit will not clear.\n");
219 }
220 
221 /* Function Description: Send the address for a read access.
222  * Return : 0 if not acknowledged, otherwise acknowledged.
223  */
224 static int envctrl_i2c_read_addr(unsigned char addr)
225 {
226 	envctrl_i2c_test_bb();
227 
228 	/* Load address. */
229 	writeb(addr + 1, i2c + PCF8584_DATA);
230 
231 	envctrl_i2c_test_bb();
232 
233 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
234 
235 	/* Wait for PIN. */
236 	envtrl_i2c_test_pin();
237 
238 	/* CSR 0 means acknowledged. */
239 	if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
240 		return readb(i2c + PCF8584_DATA);
241 	} else {
242 		writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
243 		return 0;
244 	}
245 }
246 
247 /* Function Description: Send the address for write mode.
248  * Return : None.
249  */
250 static void envctrl_i2c_write_addr(unsigned char addr)
251 {
252 	envctrl_i2c_test_bb();
253 	writeb(addr, i2c + PCF8584_DATA);
254 
255 	/* Generate Start condition. */
256 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
257 }
258 
259 /* Function Description: Read 1 byte of data from addr
260  *			 set by envctrl_i2c_read_addr()
261  * Return : Data from address set by envctrl_i2c_read_addr().
262  */
263 static unsigned char envctrl_i2c_read_data(void)
264 {
265 	envtrl_i2c_test_pin();
266 	writeb(CONTROL_ES0, i2c + PCF8584_CSR);  /* Send neg ack. */
267 	return readb(i2c + PCF8584_DATA);
268 }
269 
270 /* Function Description: Instruct the device which port to read data from.
271  * Return : None.
272  */
273 static void envctrl_i2c_write_data(unsigned char port)
274 {
275 	envtrl_i2c_test_pin();
276 	writeb(port, i2c + PCF8584_DATA);
277 }
278 
279 /* Function Description: Generate Stop condition after last byte is sent.
280  * Return : None.
281  */
282 static void envctrl_i2c_stop(void)
283 {
284 	envtrl_i2c_test_pin();
285 	writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
286 }
287 
288 /* Function Description: Read adc device.
289  * Return : Data at address and port.
290  */
291 static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
292 {
293 	/* Send address. */
294 	envctrl_i2c_write_addr(addr);
295 
296 	/* Setup port to read. */
297 	envctrl_i2c_write_data(port);
298 	envctrl_i2c_stop();
299 
300 	/* Read port. */
301 	envctrl_i2c_read_addr(addr);
302 
303 	/* Do a single byte read and send stop. */
304 	envctrl_i2c_read_data();
305 	envctrl_i2c_stop();
306 
307 	return readb(i2c + PCF8584_DATA);
308 }
309 
310 /* Function Description: Read gpio device.
311  * Return : Data at address.
312  */
313 static unsigned char envctrl_i2c_read_8574(unsigned char addr)
314 {
315 	unsigned char rd;
316 
317 	envctrl_i2c_read_addr(addr);
318 
319 	/* Do a single byte read and send stop. */
320 	rd = envctrl_i2c_read_data();
321 	envctrl_i2c_stop();
322 	return rd;
323 }
324 
325 /* Function Description: Decode data read from an adc device using firmware
326  *                       table.
327  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
328  */
329 static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
330 				      int scale, char *tbl, char *bufdata)
331 {
332 	int len = 0;
333 
334 	switch (translate_type) {
335 	case ENVCTRL_TRANSLATE_NO:
336 		/* No decode necessary. */
337 		len = 1;
338 		bufdata[0] = data;
339 		break;
340 
341 	case ENVCTRL_TRANSLATE_FULL:
342 		/* Decode this way: data = table[data]. */
343 		len = 1;
344 		bufdata[0] = tbl[data];
345 		break;
346 
347 	case ENVCTRL_TRANSLATE_SCALE:
348 		/* Decode this way: data = table[data]/scale */
349 		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
350 		len = strlen(bufdata);
351 		bufdata[len - 1] = bufdata[len - 2];
352 		bufdata[len - 2] = '.';
353 		break;
354 
355 	default:
356 		break;
357 	};
358 
359 	return len;
360 }
361 
362 /* Function Description: Read cpu-related data such as cpu temperature, voltage.
363  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
364  */
365 static int envctrl_read_cpu_info(int cpu, struct i2c_child_t *pchild,
366 				 char mon_type, unsigned char *bufdata)
367 {
368 	unsigned char data;
369 	int i;
370 	char *tbl, j = -1;
371 
372 	/* Find the right monitor type and channel. */
373 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
374 		if (pchild->mon_type[i] == mon_type) {
375 			if (++j == cpu) {
376 				break;
377 			}
378 		}
379 	}
380 
381 	if (j != cpu)
382 		return 0;
383 
384         /* Read data from address and port. */
385 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
386 				     (unsigned char)pchild->chnl_array[i].chnl_no);
387 
388 	/* Find decoding table. */
389 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
390 
391 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
392 					  pchild->tblprop_array[i].scale,
393 					  tbl, bufdata);
394 }
395 
396 /* Function Description: Read noncpu-related data such as motherboard
397  *                       temperature.
398  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
399  */
400 static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
401 				    char mon_type, unsigned char *bufdata)
402 {
403 	unsigned char data;
404 	int i;
405 	char *tbl = NULL;
406 
407 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
408 		if (pchild->mon_type[i] == mon_type)
409 			break;
410 	}
411 
412 	if (i >= PCF8584_MAX_CHANNELS)
413 		return 0;
414 
415         /* Read data from address and port. */
416 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
417 				     (unsigned char)pchild->chnl_array[i].chnl_no);
418 
419 	/* Find decoding table. */
420 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
421 
422 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
423 					  pchild->tblprop_array[i].scale,
424 					  tbl, bufdata);
425 }
426 
427 /* Function Description: Read fan status.
428  * Return : Always 1 byte. Status stored in bufdata.
429  */
430 static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
431 				  unsigned char data,
432 				  char *bufdata)
433 {
434 	unsigned char tmp, ret = 0;
435 	int i, j = 0;
436 
437 	tmp = data & pchild->fan_mask;
438 
439 	if (tmp == pchild->fan_mask) {
440 		/* All bits are on. All fans are functioning. */
441 		ret = ENVCTRL_ALL_FANS_GOOD;
442 	} else if (tmp == 0) {
443 		/* No bits are on. No fans are functioning. */
444 		ret = ENVCTRL_ALL_FANS_BAD;
445 	} else {
446 		/* Go through all channels, mark 'on' the matched bits.
447 		 * Notice that fan_mask may have discontiguous bits but
448 		 * return mask are always contiguous. For example if we
449 		 * monitor 4 fans at channels 0,1,2,4, the return mask
450 		 * should be 00010000 if only fan at channel 4 is working.
451 		 */
452 		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
453 			if (pchild->fan_mask & chnls_mask[i]) {
454 				if (!(chnls_mask[i] & tmp))
455 					ret |= chnls_mask[j];
456 
457 				j++;
458 			}
459 		}
460 	}
461 
462 	bufdata[0] = ret;
463 	return 1;
464 }
465 
466 /* Function Description: Read global addressing line.
467  * Return : Always 1 byte. Status stored in bufdata.
468  */
469 static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
470 				  unsigned char data,
471 				  char *bufdata)
472 {
473 	/* Translatation table is not necessary, as global
474 	 * addr is the integer value of the GA# bits.
475 	 *
476 	 * NOTE: MSB is documented as zero, but I see it as '1' always....
477 	 *
478 	 * -----------------------------------------------
479 	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
480 	 * -----------------------------------------------
481 	 * GA0 - GA4	integer value of Global Address (backplane slot#)
482 	 * DEG			0 = cPCI Power supply output is starting to degrade
483 	 * 				1 = cPCI Power supply output is OK
484 	 * FAL			0 = cPCI Power supply has failed
485 	 * 				1 = cPCI Power supply output is OK
486 	 */
487 	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
488 	return 1;
489 }
490 
491 /* Function Description: Read standard voltage and power supply status.
492  * Return : Always 1 byte. Status stored in bufdata.
493  */
494 static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
495 						unsigned char data,
496 						char *bufdata)
497 {
498 	unsigned char tmp, ret = 0;
499 	int i, j = 0;
500 
501 	tmp = data & pchild->voltage_mask;
502 
503 	/* Two channels are used to monitor voltage and power supply. */
504 	if (tmp == pchild->voltage_mask) {
505 		/* All bits are on. Voltage and power supply are okay. */
506 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
507 	} else if (tmp == 0) {
508 		/* All bits are off. Voltage and power supply are bad */
509 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
510 	} else {
511 		/* Either voltage or power supply has problem. */
512 		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
513 			if (pchild->voltage_mask & chnls_mask[i]) {
514 				j++;
515 
516 				/* Break out when there is a mismatch. */
517 				if (!(chnls_mask[i] & tmp))
518 					break;
519 			}
520 		}
521 
522 		/* Make a wish that hardware will always use the
523 		 * first channel for voltage and the second for
524 		 * power supply.
525 		 */
526 		if (j == 1)
527 			ret = ENVCTRL_VOLTAGE_BAD;
528 		else
529 			ret = ENVCTRL_POWERSUPPLY_BAD;
530 	}
531 
532 	bufdata[0] = ret;
533 	return 1;
534 }
535 
536 /* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
537  * Return: Number of read bytes. 0 for error.
538  */
539 static ssize_t
540 envctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
541 {
542 	struct i2c_child_t *pchild;
543 	unsigned char data[10];
544 	int ret = 0;
545 
546 	/* Get the type of read as decided in ioctl() call.
547 	 * Find the appropriate i2c child.
548 	 * Get the data and put back to the user buffer.
549 	 */
550 
551 	switch ((int)(long)file->private_data) {
552 	case ENVCTRL_RD_WARNING_TEMPERATURE:
553 		if (warning_temperature == 0)
554 			return 0;
555 
556 		data[0] = (unsigned char)(warning_temperature);
557 		ret = 1;
558 		if (copy_to_user(buf, data, ret))
559 			ret = -EFAULT;
560 		break;
561 
562 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
563 		if (shutdown_temperature == 0)
564 			return 0;
565 
566 		data[0] = (unsigned char)(shutdown_temperature);
567 		ret = 1;
568 		if (copy_to_user(buf, data, ret))
569 			ret = -EFAULT;
570 		break;
571 
572 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
573 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
574 			return 0;
575 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
576 		if (copy_to_user(buf, data, ret))
577 			ret = -EFAULT;
578 		break;
579 
580 	case ENVCTRL_RD_CPU_TEMPERATURE:
581 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
582 			return 0;
583 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUTEMP_MON, data);
584 
585 		/* Reset cpu to the default cpu0. */
586 		if (copy_to_user(buf, data, ret))
587 			ret = -EFAULT;
588 		break;
589 
590 	case ENVCTRL_RD_CPU_VOLTAGE:
591 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
592 			return 0;
593 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUVOLTAGE_MON, data);
594 
595 		/* Reset cpu to the default cpu0. */
596 		if (copy_to_user(buf, data, ret))
597 			ret = -EFAULT;
598 		break;
599 
600 	case ENVCTRL_RD_SCSI_TEMPERATURE:
601 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
602 			return 0;
603 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
604 		if (copy_to_user(buf, data, ret))
605 			ret = -EFAULT;
606 		break;
607 
608 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
609 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
610 			return 0;
611 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
612 		if (copy_to_user(buf, data, ret))
613 			ret = -EFAULT;
614 		break;
615 
616 	case ENVCTRL_RD_FAN_STATUS:
617 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
618 			return 0;
619 		data[0] = envctrl_i2c_read_8574(pchild->addr);
620 		ret = envctrl_i2c_fan_status(pchild,data[0], data);
621 		if (copy_to_user(buf, data, ret))
622 			ret = -EFAULT;
623 		break;
624 
625 	case ENVCTRL_RD_GLOBALADDRESS:
626 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
627 			return 0;
628 		data[0] = envctrl_i2c_read_8574(pchild->addr);
629 		ret = envctrl_i2c_globaladdr(pchild, data[0], data);
630 		if (copy_to_user(buf, data, ret))
631 			ret = -EFAULT;
632 		break;
633 
634 	case ENVCTRL_RD_VOLTAGE_STATUS:
635 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
636 			/* If voltage monitor not present, check for CPCI equivalent */
637 			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
638 				return 0;
639 		data[0] = envctrl_i2c_read_8574(pchild->addr);
640 		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
641 		if (copy_to_user(buf, data, ret))
642 			ret = -EFAULT;
643 		break;
644 
645 	default:
646 		break;
647 
648 	};
649 
650 	return ret;
651 }
652 
653 /* Function Description: Command what to read.  Mapped to user ioctl().
654  * Return: Gives 0 for implemented commands, -EINVAL otherwise.
655  */
656 static long
657 envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
658 {
659 	char __user *infobuf;
660 
661 	switch (cmd) {
662 	case ENVCTRL_RD_WARNING_TEMPERATURE:
663 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
664 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
665 	case ENVCTRL_RD_FAN_STATUS:
666 	case ENVCTRL_RD_VOLTAGE_STATUS:
667 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
668 	case ENVCTRL_RD_SCSI_TEMPERATURE:
669 	case ENVCTRL_RD_GLOBALADDRESS:
670 		file->private_data = (void *)(long)cmd;
671 		break;
672 
673 	case ENVCTRL_RD_CPU_TEMPERATURE:
674 	case ENVCTRL_RD_CPU_VOLTAGE:
675 		/* Check to see if application passes in any cpu number,
676 		 * the default is cpu0.
677 		 */
678 		infobuf = (char __user *) arg;
679 		if (infobuf == NULL) {
680 			read_cpu = 0;
681 		}else {
682 			get_user(read_cpu, infobuf);
683 		}
684 
685 		/* Save the command for use when reading. */
686 		file->private_data = (void *)(long)cmd;
687 		break;
688 
689 	default:
690 		return -EINVAL;
691 	};
692 
693 	return 0;
694 }
695 
696 /* Function Description: open device. Mapped to user open().
697  * Return: Always 0.
698  */
699 static int
700 envctrl_open(struct inode *inode, struct file *file)
701 {
702 	cycle_kernel_lock();
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 const 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 			    const 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, struct device_node *dp)
772 {
773 	int i = 0, len;
774 	const char *pos;
775 	const unsigned int *pval;
776 
777 	/* Firmware describe channels into a stream separated by a '\0'. */
778 	pos = of_get_property(dp, "channels-description", &len);
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 	pval = of_get_property(dp, "warning-temp", NULL);
789 	if (pval)
790 		warning_temperature = *pval;
791 
792 	pval = of_get_property(dp, "shutdown-temp", NULL);
793 	if (pval)
794 		shutdown_temperature = *pval;
795 }
796 
797 /* Function Description: Initialize child device monitoring fan status.
798  * Return: None.
799  */
800 static void envctrl_init_fanstat(struct i2c_child_t *pchild)
801 {
802 	int i;
803 
804 	/* Go through all channels and set up the mask. */
805 	for (i = 0; i < pchild->total_chnls; i++)
806 		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
807 
808 	/* We only need to know if this child has fan status monitored.
809 	 * We don't care which channels since we have the mask already.
810 	 */
811 	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
812 }
813 
814 /* Function Description: Initialize child device for global addressing line.
815  * Return: None.
816  */
817 static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
818 {
819 	int i;
820 
821 	/* Voltage/PowerSupply monitoring is piggybacked
822 	 * with Global Address on CompactPCI.  See comments
823 	 * within envctrl_i2c_globaladdr for bit assignments.
824 	 *
825 	 * The mask is created here by assigning mask bits to each
826 	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
827 	 * Channel numbers are not consecutive within the globaladdr
828 	 * node (why?), so we use the actual counter value as chnls_mask
829 	 * index instead of the chnl_array[x].chnl_no value.
830 	 *
831 	 * NOTE: This loop could be replaced with a constant representing
832 	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
833 	 */
834 	for (i = 0; i < pchild->total_chnls; i++) {
835 		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
836 			pchild->voltage_mask |= chnls_mask[i];
837 		}
838 	}
839 
840 	/* We only need to know if this child has global addressing
841 	 * line monitored.  We don't care which channels since we know
842 	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
843 	 */
844 	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
845 }
846 
847 /* Initialize child device monitoring voltage status. */
848 static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
849 {
850 	int i;
851 
852 	/* Go through all channels and set up the mask. */
853 	for (i = 0; i < pchild->total_chnls; i++)
854 		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
855 
856 	/* We only need to know if this child has voltage status monitored.
857 	 * We don't care which channels since we have the mask already.
858 	 */
859 	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
860 }
861 
862 /* Function Description: Initialize i2c child device.
863  * Return: None.
864  */
865 static void envctrl_init_i2c_child(struct device_node *dp,
866 				   struct i2c_child_t *pchild)
867 {
868 	int len, i, tbls_size = 0;
869 	const void *pval;
870 
871 	/* Get device address. */
872 	pval = of_get_property(dp, "reg", &len);
873 	memcpy(&pchild->addr, pval, len);
874 
875 	/* Get tables property.  Read firmware temperature tables. */
876 	pval = of_get_property(dp, "translation", &len);
877 	if (pval && len > 0) {
878 		memcpy(pchild->tblprop_array, pval, len);
879                 pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
880 		for (i = 0; i < pchild->total_tbls; i++) {
881 			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
882 				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
883 			}
884 		}
885 
886                 pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
887 		if (pchild->tables == NULL){
888 			printk(KERN_ERR PFX "Failed to allocate table.\n");
889 			return;
890 		}
891 		pval = of_get_property(dp, "tables", &len);
892                 if (!pval || len <= 0) {
893 			printk(KERN_ERR PFX "Failed to get table.\n");
894 			return;
895 		}
896 		memcpy(pchild->tables, pval, len);
897 	}
898 
899 	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
900 	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
901 	 * "For Factory Use Only."
902 	 *
903 	 * We ignore the node on these platforms by assigning the
904 	 * 'NULL' monitor type.
905 	 */
906 	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
907 		struct device_node *root_node;
908 		int len;
909 
910 		root_node = of_find_node_by_path("/");
911 		if (!strcmp(root_node->name, "SUNW,UltraSPARC-IIi-cEngine")) {
912 			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
913 				pchild->mon_type[len] = ENVCTRL_NOMON;
914 			}
915 			return;
916 		}
917 	}
918 
919 	/* Get the monitor channels. */
920 	pval = of_get_property(dp, "channels-in-use", &len);
921 	memcpy(pchild->chnl_array, pval, len);
922 	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
923 
924 	for (i = 0; i < pchild->total_chnls; i++) {
925 		switch (pchild->chnl_array[i].type) {
926 		case PCF8584_TEMP_TYPE:
927 			envctrl_init_adc(pchild, dp);
928 			break;
929 
930 		case PCF8584_GLOBALADDR_TYPE:
931 			envctrl_init_globaladdr(pchild);
932 			i = pchild->total_chnls;
933 			break;
934 
935 		case PCF8584_FANSTAT_TYPE:
936 			envctrl_init_fanstat(pchild);
937 			i = pchild->total_chnls;
938 			break;
939 
940 		case PCF8584_VOLTAGE_TYPE:
941 			if (pchild->i2ctype == I2C_ADC) {
942 				envctrl_init_adc(pchild,dp);
943 			} else {
944 				envctrl_init_voltage_status(pchild);
945 			}
946 			i = pchild->total_chnls;
947 			break;
948 
949 		default:
950 			break;
951 		};
952 	}
953 }
954 
955 /* Function Description: Search the child device list for a device.
956  * Return : The i2c child if found. NULL otherwise.
957  */
958 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
959 {
960 	int i, j;
961 
962 	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
963 		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
964 			if (i2c_childlist[i].mon_type[j] == mon_type) {
965 				return (struct i2c_child_t *)(&(i2c_childlist[i]));
966 			}
967 		}
968 	}
969 	return NULL;
970 }
971 
972 static void envctrl_do_shutdown(void)
973 {
974 	static int inprog = 0;
975 	int ret;
976 
977 	if (inprog != 0)
978 		return;
979 
980 	inprog = 1;
981 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
982 	ret = orderly_poweroff(true);
983 	if (ret < 0) {
984 		printk(KERN_CRIT "kenvctrld: WARNING: system shutdown failed!\n");
985 		inprog = 0;  /* unlikely to succeed, but we could try again */
986 	}
987 }
988 
989 static struct task_struct *kenvctrld_task;
990 
991 static int kenvctrld(void *__unused)
992 {
993 	int poll_interval;
994 	int whichcpu;
995 	char tempbuf[10];
996 	struct i2c_child_t *cputemp;
997 
998 	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
999 		printk(KERN_ERR  PFX
1000 		       "kenvctrld unable to monitor CPU temp-- exiting\n");
1001 		return -ENODEV;
1002 	}
1003 
1004 	poll_interval = 5000; /* TODO env_mon_interval */
1005 
1006 	printk(KERN_INFO PFX "%s starting...\n", current->comm);
1007 	for (;;) {
1008 		msleep_interruptible(poll_interval);
1009 
1010 		if (kthread_should_stop())
1011 			break;
1012 
1013 		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
1014 			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
1015 						      ENVCTRL_CPUTEMP_MON,
1016 						      tempbuf)) {
1017 				if (tempbuf[0] >= shutdown_temperature) {
1018 					printk(KERN_CRIT
1019 						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
1020 						"shutdown threshold %i C\n",
1021 						current->comm, whichcpu,
1022 						tempbuf[0], shutdown_temperature);
1023 					envctrl_do_shutdown();
1024 				}
1025 			}
1026 		}
1027 	}
1028 	printk(KERN_INFO PFX "%s exiting...\n", current->comm);
1029 	return 0;
1030 }
1031 
1032 static int __devinit envctrl_probe(struct of_device *op,
1033 				   const struct of_device_id *match)
1034 {
1035 	struct device_node *dp;
1036 	int index, err;
1037 
1038 	if (i2c)
1039 		return -EINVAL;
1040 
1041 	i2c = of_ioremap(&op->resource[0], 0, 0x2, DRIVER_NAME);
1042 	if (!i2c)
1043 		return -ENOMEM;
1044 
1045 	index = 0;
1046 	dp = op->node->child;
1047 	while (dp) {
1048 		if (!strcmp(dp->name, "gpio")) {
1049 			i2c_childlist[index].i2ctype = I2C_GPIO;
1050 			envctrl_init_i2c_child(dp, &(i2c_childlist[index++]));
1051 		} else if (!strcmp(dp->name, "adc")) {
1052 			i2c_childlist[index].i2ctype = I2C_ADC;
1053 			envctrl_init_i2c_child(dp, &(i2c_childlist[index++]));
1054 		}
1055 
1056 		dp = dp->sibling;
1057 	}
1058 
1059 	/* Set device address. */
1060 	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
1061 	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
1062 
1063 	/* Set system clock and SCL frequencies. */
1064 	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
1065 	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
1066 
1067 	/* Enable serial interface. */
1068 	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
1069 	udelay(200);
1070 
1071 	/* Register the device as a minor miscellaneous device. */
1072 	err = misc_register(&envctrl_dev);
1073 	if (err) {
1074 		printk(KERN_ERR PFX "Unable to get misc minor %d\n",
1075 		       envctrl_dev.minor);
1076 		goto out_iounmap;
1077 	}
1078 
1079 	/* Note above traversal routine post-incremented 'i' to accommodate
1080 	 * a next child device, so we decrement before reverse-traversal of
1081 	 * child devices.
1082 	 */
1083 	printk(KERN_INFO PFX "Initialized ");
1084 	for (--index; index >= 0; --index) {
1085 		printk("[%s 0x%lx]%s",
1086 			(I2C_ADC == i2c_childlist[index].i2ctype) ? "adc" :
1087 			((I2C_GPIO == i2c_childlist[index].i2ctype) ? "gpio" : "unknown"),
1088 			i2c_childlist[index].addr, (0 == index) ? "\n" : " ");
1089 	}
1090 
1091 	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
1092 	if (IS_ERR(kenvctrld_task)) {
1093 		err = PTR_ERR(kenvctrld_task);
1094 		goto out_deregister;
1095 	}
1096 
1097 	return 0;
1098 
1099 out_deregister:
1100 	misc_deregister(&envctrl_dev);
1101 out_iounmap:
1102 	of_iounmap(&op->resource[0], i2c, 0x2);
1103 	for (index = 0; index < ENVCTRL_MAX_CPU * 2; index++)
1104 		kfree(i2c_childlist[index].tables);
1105 
1106 	return err;
1107 }
1108 
1109 static int __devexit envctrl_remove(struct of_device *op)
1110 {
1111 	int index;
1112 
1113 	kthread_stop(kenvctrld_task);
1114 
1115 	of_iounmap(&op->resource[0], i2c, 0x2);
1116 	misc_deregister(&envctrl_dev);
1117 
1118 	for (index = 0; index < ENVCTRL_MAX_CPU * 2; index++)
1119 		kfree(i2c_childlist[index].tables);
1120 
1121 	return 0;
1122 }
1123 
1124 static const struct of_device_id envctrl_match[] = {
1125 	{
1126 		.name = "i2c",
1127 		.compatible = "i2cpcf,8584",
1128 	},
1129 	{},
1130 };
1131 MODULE_DEVICE_TABLE(of, envctrl_match);
1132 
1133 static struct of_platform_driver envctrl_driver = {
1134 	.name		= DRIVER_NAME,
1135 	.match_table	= envctrl_match,
1136 	.probe		= envctrl_probe,
1137 	.remove		= __devexit_p(envctrl_remove),
1138 };
1139 
1140 static int __init envctrl_init(void)
1141 {
1142 	return of_register_driver(&envctrl_driver, &of_bus_type);
1143 }
1144 
1145 static void __exit envctrl_exit(void)
1146 {
1147 	of_unregister_driver(&envctrl_driver);
1148 }
1149 
1150 module_init(envctrl_init);
1151 module_exit(envctrl_exit);
1152 MODULE_LICENSE("GPL");
1153