xref: /linux/drivers/sbus/char/envctrl.c (revision a2cce7a9f1b8cc3d4edce106fb971529f1d4d9ce)
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/kthread.h>
23 #include <linux/delay.h>
24 #include <linux/ioport.h>
25 #include <linux/miscdevice.h>
26 #include <linux/kmod.h>
27 #include <linux/reboot.h>
28 #include <linux/slab.h>
29 #include <linux/of.h>
30 #include <linux/of_device.h>
31 
32 #include <asm/uaccess.h>
33 #include <asm/envctrl.h>
34 #include <asm/io.h>
35 
36 #define DRIVER_NAME	"envctrl"
37 #define PFX		DRIVER_NAME ": "
38 
39 #define ENVCTRL_MINOR	162
40 
41 #define PCF8584_ADDRESS	0x55
42 
43 #define CONTROL_PIN	0x80
44 #define CONTROL_ES0	0x40
45 #define CONTROL_ES1	0x20
46 #define CONTROL_ES2	0x10
47 #define CONTROL_ENI	0x08
48 #define CONTROL_STA	0x04
49 #define CONTROL_STO	0x02
50 #define CONTROL_ACK	0x01
51 
52 #define STATUS_PIN	0x80
53 #define STATUS_STS	0x20
54 #define STATUS_BER	0x10
55 #define STATUS_LRB	0x08
56 #define STATUS_AD0	0x08
57 #define STATUS_AAB	0x04
58 #define STATUS_LAB	0x02
59 #define STATUS_BB	0x01
60 
61 /*
62  * CLK Mode Register.
63  */
64 #define BUS_CLK_90	0x00
65 #define BUS_CLK_45	0x01
66 #define BUS_CLK_11	0x02
67 #define BUS_CLK_1_5	0x03
68 
69 #define CLK_3		0x00
70 #define CLK_4_43	0x10
71 #define CLK_6		0x14
72 #define CLK_8		0x18
73 #define CLK_12		0x1c
74 
75 #define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
76 #define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */
77 
78 /* Monitor type of i2c child device.
79  * Firmware definitions.
80  */
81 #define PCF8584_MAX_CHANNELS            8
82 #define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
83 #define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
84 #define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
85 #define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/
86 
87 /* Monitor type of i2c child device.
88  * Driver definitions.
89  */
90 #define ENVCTRL_NOMON				0
91 #define ENVCTRL_CPUTEMP_MON			1    /* cpu temperature monitor */
92 #define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
93 #define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
94 #define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperature */
95 					     /* monitor                     */
96 #define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
97 #define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
98 #define ENVCTRL_SCSITEMP_MON		7    /* scsi temperature */
99 #define ENVCTRL_GLOBALADDR_MON		8    /* global address */
100 
101 /* Child device type.
102  * Driver definitions.
103  */
104 #define I2C_ADC				0    /* pcf8591 */
105 #define I2C_GPIO			1    /* pcf8571 */
106 
107 /* Data read from child device may need to decode
108  * through a data table and a scale.
109  * Translation type as defined by firmware.
110  */
111 #define ENVCTRL_TRANSLATE_NO		0
112 #define ENVCTRL_TRANSLATE_PARTIAL	1
113 #define ENVCTRL_TRANSLATE_COMBINED	2
114 #define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
115 #define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */
116 
117 /* Driver miscellaneous definitions. */
118 #define ENVCTRL_MAX_CPU			4
119 #define CHANNEL_DESC_SZ			256
120 
121 /* Mask values for combined GlobalAddress/PowerStatus node */
122 #define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
123 #define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60
124 
125 /* Node 0x70 ignored on CompactPCI CP1400/1500 platforms
126  * (see envctrl_init_i2c_child)
127  */
128 #define ENVCTRL_CPCI_IGNORED_NODE		0x70
129 
130 #define PCF8584_DATA	0x00
131 #define PCF8584_CSR	0x01
132 
133 /* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
134  * Property of a port or channel as defined by the firmware.
135  */
136 struct pcf8584_channel {
137         unsigned char chnl_no;
138         unsigned char io_direction;
139         unsigned char type;
140         unsigned char last;
141 };
142 
143 /* Each child device may have one or more tables of bytes to help decode
144  * data. Table property as defined by the firmware.
145  */
146 struct pcf8584_tblprop {
147         unsigned int type;
148         unsigned int scale;
149         unsigned int offset; /* offset from the beginning of the table */
150         unsigned int size;
151 };
152 
153 /* i2c child */
154 struct i2c_child_t {
155 	/* Either ADC or GPIO. */
156 	unsigned char i2ctype;
157         unsigned long addr;
158         struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];
159 
160 	/* Channel info. */
161 	unsigned int total_chnls;	/* Number of monitor channels. */
162 	unsigned char fan_mask;		/* Byte mask for fan status channels. */
163 	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
164         struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];
165 
166 	/* Properties of all monitor channels. */
167 	unsigned int total_tbls;	/* Number of monitor tables. */
168         char *tables;			/* Pointer to table(s). */
169 	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
170 	char mon_type[PCF8584_MAX_CHANNELS];
171 };
172 
173 static void __iomem *i2c;
174 static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
175 static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
176 static unsigned int warning_temperature = 0;
177 static unsigned int shutdown_temperature = 0;
178 static char read_cpu;
179 
180 /* Forward declarations. */
181 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);
182 
183 /* Function Description: Test the PIN bit (Pending Interrupt Not)
184  * 			 to test when serial transmission is completed .
185  * Return : None.
186  */
187 static void envtrl_i2c_test_pin(void)
188 {
189 	int limit = 1000000;
190 
191 	while (--limit > 0) {
192 		if (!(readb(i2c + PCF8584_CSR) & STATUS_PIN))
193 			break;
194 		udelay(1);
195 	}
196 
197 	if (limit <= 0)
198 		printk(KERN_INFO PFX "Pin status will not clear.\n");
199 }
200 
201 /* Function Description: Test busy bit.
202  * Return : None.
203  */
204 static void envctrl_i2c_test_bb(void)
205 {
206 	int limit = 1000000;
207 
208 	while (--limit > 0) {
209 		/* Busy bit 0 means busy. */
210 		if (readb(i2c + PCF8584_CSR) & STATUS_BB)
211 			break;
212 		udelay(1);
213 	}
214 
215 	if (limit <= 0)
216 		printk(KERN_INFO PFX "Busy bit will not clear.\n");
217 }
218 
219 /* Function Description: Send the address for a read access.
220  * Return : 0 if not acknowledged, otherwise acknowledged.
221  */
222 static int envctrl_i2c_read_addr(unsigned char addr)
223 {
224 	envctrl_i2c_test_bb();
225 
226 	/* Load address. */
227 	writeb(addr + 1, i2c + PCF8584_DATA);
228 
229 	envctrl_i2c_test_bb();
230 
231 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
232 
233 	/* Wait for PIN. */
234 	envtrl_i2c_test_pin();
235 
236 	/* CSR 0 means acknowledged. */
237 	if (!(readb(i2c + PCF8584_CSR) & STATUS_LRB)) {
238 		return readb(i2c + PCF8584_DATA);
239 	} else {
240 		writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
241 		return 0;
242 	}
243 }
244 
245 /* Function Description: Send the address for write mode.
246  * Return : None.
247  */
248 static void envctrl_i2c_write_addr(unsigned char addr)
249 {
250 	envctrl_i2c_test_bb();
251 	writeb(addr, i2c + PCF8584_DATA);
252 
253 	/* Generate Start condition. */
254 	writeb(OBD_SEND_START, i2c + PCF8584_CSR);
255 }
256 
257 /* Function Description: Read 1 byte of data from addr
258  *			 set by envctrl_i2c_read_addr()
259  * Return : Data from address set by envctrl_i2c_read_addr().
260  */
261 static unsigned char envctrl_i2c_read_data(void)
262 {
263 	envtrl_i2c_test_pin();
264 	writeb(CONTROL_ES0, i2c + PCF8584_CSR);  /* Send neg ack. */
265 	return readb(i2c + PCF8584_DATA);
266 }
267 
268 /* Function Description: Instruct the device which port to read data from.
269  * Return : None.
270  */
271 static void envctrl_i2c_write_data(unsigned char port)
272 {
273 	envtrl_i2c_test_pin();
274 	writeb(port, i2c + PCF8584_DATA);
275 }
276 
277 /* Function Description: Generate Stop condition after last byte is sent.
278  * Return : None.
279  */
280 static void envctrl_i2c_stop(void)
281 {
282 	envtrl_i2c_test_pin();
283 	writeb(OBD_SEND_STOP, i2c + PCF8584_CSR);
284 }
285 
286 /* Function Description: Read adc device.
287  * Return : Data at address and port.
288  */
289 static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
290 {
291 	/* Send address. */
292 	envctrl_i2c_write_addr(addr);
293 
294 	/* Setup port to read. */
295 	envctrl_i2c_write_data(port);
296 	envctrl_i2c_stop();
297 
298 	/* Read port. */
299 	envctrl_i2c_read_addr(addr);
300 
301 	/* Do a single byte read and send stop. */
302 	envctrl_i2c_read_data();
303 	envctrl_i2c_stop();
304 
305 	return readb(i2c + PCF8584_DATA);
306 }
307 
308 /* Function Description: Read gpio device.
309  * Return : Data at address.
310  */
311 static unsigned char envctrl_i2c_read_8574(unsigned char addr)
312 {
313 	unsigned char rd;
314 
315 	envctrl_i2c_read_addr(addr);
316 
317 	/* Do a single byte read and send stop. */
318 	rd = envctrl_i2c_read_data();
319 	envctrl_i2c_stop();
320 	return rd;
321 }
322 
323 /* Function Description: Decode data read from an adc device using firmware
324  *                       table.
325  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
326  */
327 static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
328 				      int scale, char *tbl, char *bufdata)
329 {
330 	int len = 0;
331 
332 	switch (translate_type) {
333 	case ENVCTRL_TRANSLATE_NO:
334 		/* No decode necessary. */
335 		len = 1;
336 		bufdata[0] = data;
337 		break;
338 
339 	case ENVCTRL_TRANSLATE_FULL:
340 		/* Decode this way: data = table[data]. */
341 		len = 1;
342 		bufdata[0] = tbl[data];
343 		break;
344 
345 	case ENVCTRL_TRANSLATE_SCALE:
346 		/* Decode this way: data = table[data]/scale */
347 		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
348 		len = strlen(bufdata);
349 		bufdata[len - 1] = bufdata[len - 2];
350 		bufdata[len - 2] = '.';
351 		break;
352 
353 	default:
354 		break;
355 	}
356 
357 	return len;
358 }
359 
360 /* Function Description: Read cpu-related data such as cpu temperature, voltage.
361  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
362  */
363 static int envctrl_read_cpu_info(int cpu, struct i2c_child_t *pchild,
364 				 char mon_type, unsigned char *bufdata)
365 {
366 	unsigned char data;
367 	int i;
368 	char *tbl, j = -1;
369 
370 	/* Find the right monitor type and channel. */
371 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
372 		if (pchild->mon_type[i] == mon_type) {
373 			if (++j == cpu) {
374 				break;
375 			}
376 		}
377 	}
378 
379 	if (j != cpu)
380 		return 0;
381 
382         /* Read data from address and port. */
383 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
384 				     (unsigned char)pchild->chnl_array[i].chnl_no);
385 
386 	/* Find decoding table. */
387 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
388 
389 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
390 					  pchild->tblprop_array[i].scale,
391 					  tbl, bufdata);
392 }
393 
394 /* Function Description: Read noncpu-related data such as motherboard
395  *                       temperature.
396  * Return: Number of read bytes. Data is stored in bufdata in ascii format.
397  */
398 static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
399 				    char mon_type, unsigned char *bufdata)
400 {
401 	unsigned char data;
402 	int i;
403 	char *tbl = NULL;
404 
405 	for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
406 		if (pchild->mon_type[i] == mon_type)
407 			break;
408 	}
409 
410 	if (i >= PCF8584_MAX_CHANNELS)
411 		return 0;
412 
413         /* Read data from address and port. */
414 	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
415 				     (unsigned char)pchild->chnl_array[i].chnl_no);
416 
417 	/* Find decoding table. */
418 	tbl = pchild->tables + pchild->tblprop_array[i].offset;
419 
420 	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
421 					  pchild->tblprop_array[i].scale,
422 					  tbl, bufdata);
423 }
424 
425 /* Function Description: Read fan status.
426  * Return : Always 1 byte. Status stored in bufdata.
427  */
428 static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
429 				  unsigned char data,
430 				  char *bufdata)
431 {
432 	unsigned char tmp, ret = 0;
433 	int i, j = 0;
434 
435 	tmp = data & pchild->fan_mask;
436 
437 	if (tmp == pchild->fan_mask) {
438 		/* All bits are on. All fans are functioning. */
439 		ret = ENVCTRL_ALL_FANS_GOOD;
440 	} else if (tmp == 0) {
441 		/* No bits are on. No fans are functioning. */
442 		ret = ENVCTRL_ALL_FANS_BAD;
443 	} else {
444 		/* Go through all channels, mark 'on' the matched bits.
445 		 * Notice that fan_mask may have discontiguous bits but
446 		 * return mask are always contiguous. For example if we
447 		 * monitor 4 fans at channels 0,1,2,4, the return mask
448 		 * should be 00010000 if only fan at channel 4 is working.
449 		 */
450 		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
451 			if (pchild->fan_mask & chnls_mask[i]) {
452 				if (!(chnls_mask[i] & tmp))
453 					ret |= chnls_mask[j];
454 
455 				j++;
456 			}
457 		}
458 	}
459 
460 	bufdata[0] = ret;
461 	return 1;
462 }
463 
464 /* Function Description: Read global addressing line.
465  * Return : Always 1 byte. Status stored in bufdata.
466  */
467 static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
468 				  unsigned char data,
469 				  char *bufdata)
470 {
471 	/* Translatation table is not necessary, as global
472 	 * addr is the integer value of the GA# bits.
473 	 *
474 	 * NOTE: MSB is documented as zero, but I see it as '1' always....
475 	 *
476 	 * -----------------------------------------------
477 	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
478 	 * -----------------------------------------------
479 	 * GA0 - GA4	integer value of Global Address (backplane slot#)
480 	 * DEG			0 = cPCI Power supply output is starting to degrade
481 	 * 				1 = cPCI Power supply output is OK
482 	 * FAL			0 = cPCI Power supply has failed
483 	 * 				1 = cPCI Power supply output is OK
484 	 */
485 	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
486 	return 1;
487 }
488 
489 /* Function Description: Read standard voltage and power supply status.
490  * Return : Always 1 byte. Status stored in bufdata.
491  */
492 static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
493 						unsigned char data,
494 						char *bufdata)
495 {
496 	unsigned char tmp, ret = 0;
497 	int i, j = 0;
498 
499 	tmp = data & pchild->voltage_mask;
500 
501 	/* Two channels are used to monitor voltage and power supply. */
502 	if (tmp == pchild->voltage_mask) {
503 		/* All bits are on. Voltage and power supply are okay. */
504 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
505 	} else if (tmp == 0) {
506 		/* All bits are off. Voltage and power supply are bad */
507 		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
508 	} else {
509 		/* Either voltage or power supply has problem. */
510 		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
511 			if (pchild->voltage_mask & chnls_mask[i]) {
512 				j++;
513 
514 				/* Break out when there is a mismatch. */
515 				if (!(chnls_mask[i] & tmp))
516 					break;
517 			}
518 		}
519 
520 		/* Make a wish that hardware will always use the
521 		 * first channel for voltage and the second for
522 		 * power supply.
523 		 */
524 		if (j == 1)
525 			ret = ENVCTRL_VOLTAGE_BAD;
526 		else
527 			ret = ENVCTRL_POWERSUPPLY_BAD;
528 	}
529 
530 	bufdata[0] = ret;
531 	return 1;
532 }
533 
534 /* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
535  * Return: Number of read bytes. 0 for error.
536  */
537 static ssize_t
538 envctrl_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
539 {
540 	struct i2c_child_t *pchild;
541 	unsigned char data[10];
542 	int ret = 0;
543 
544 	/* Get the type of read as decided in ioctl() call.
545 	 * Find the appropriate i2c child.
546 	 * Get the data and put back to the user buffer.
547 	 */
548 
549 	switch ((int)(long)file->private_data) {
550 	case ENVCTRL_RD_WARNING_TEMPERATURE:
551 		if (warning_temperature == 0)
552 			return 0;
553 
554 		data[0] = (unsigned char)(warning_temperature);
555 		ret = 1;
556 		if (copy_to_user(buf, data, ret))
557 			ret = -EFAULT;
558 		break;
559 
560 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
561 		if (shutdown_temperature == 0)
562 			return 0;
563 
564 		data[0] = (unsigned char)(shutdown_temperature);
565 		ret = 1;
566 		if (copy_to_user(buf, data, ret))
567 			ret = -EFAULT;
568 		break;
569 
570 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
571 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
572 			return 0;
573 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
574 		if (copy_to_user(buf, data, ret))
575 			ret = -EFAULT;
576 		break;
577 
578 	case ENVCTRL_RD_CPU_TEMPERATURE:
579 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
580 			return 0;
581 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUTEMP_MON, data);
582 
583 		/* Reset cpu to the default cpu0. */
584 		if (copy_to_user(buf, data, ret))
585 			ret = -EFAULT;
586 		break;
587 
588 	case ENVCTRL_RD_CPU_VOLTAGE:
589 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
590 			return 0;
591 		ret = envctrl_read_cpu_info(read_cpu, pchild, ENVCTRL_CPUVOLTAGE_MON, data);
592 
593 		/* Reset cpu to the default cpu0. */
594 		if (copy_to_user(buf, data, ret))
595 			ret = -EFAULT;
596 		break;
597 
598 	case ENVCTRL_RD_SCSI_TEMPERATURE:
599 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
600 			return 0;
601 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
602 		if (copy_to_user(buf, data, ret))
603 			ret = -EFAULT;
604 		break;
605 
606 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
607 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
608 			return 0;
609 		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
610 		if (copy_to_user(buf, data, ret))
611 			ret = -EFAULT;
612 		break;
613 
614 	case ENVCTRL_RD_FAN_STATUS:
615 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
616 			return 0;
617 		data[0] = envctrl_i2c_read_8574(pchild->addr);
618 		ret = envctrl_i2c_fan_status(pchild,data[0], data);
619 		if (copy_to_user(buf, data, ret))
620 			ret = -EFAULT;
621 		break;
622 
623 	case ENVCTRL_RD_GLOBALADDRESS:
624 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
625 			return 0;
626 		data[0] = envctrl_i2c_read_8574(pchild->addr);
627 		ret = envctrl_i2c_globaladdr(pchild, data[0], data);
628 		if (copy_to_user(buf, data, ret))
629 			ret = -EFAULT;
630 		break;
631 
632 	case ENVCTRL_RD_VOLTAGE_STATUS:
633 		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
634 			/* If voltage monitor not present, check for CPCI equivalent */
635 			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
636 				return 0;
637 		data[0] = envctrl_i2c_read_8574(pchild->addr);
638 		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
639 		if (copy_to_user(buf, data, ret))
640 			ret = -EFAULT;
641 		break;
642 
643 	default:
644 		break;
645 
646 	}
647 
648 	return ret;
649 }
650 
651 /* Function Description: Command what to read.  Mapped to user ioctl().
652  * Return: Gives 0 for implemented commands, -EINVAL otherwise.
653  */
654 static long
655 envctrl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
656 {
657 	char __user *infobuf;
658 
659 	switch (cmd) {
660 	case ENVCTRL_RD_WARNING_TEMPERATURE:
661 	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
662 	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
663 	case ENVCTRL_RD_FAN_STATUS:
664 	case ENVCTRL_RD_VOLTAGE_STATUS:
665 	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
666 	case ENVCTRL_RD_SCSI_TEMPERATURE:
667 	case ENVCTRL_RD_GLOBALADDRESS:
668 		file->private_data = (void *)(long)cmd;
669 		break;
670 
671 	case ENVCTRL_RD_CPU_TEMPERATURE:
672 	case ENVCTRL_RD_CPU_VOLTAGE:
673 		/* Check to see if application passes in any cpu number,
674 		 * the default is cpu0.
675 		 */
676 		infobuf = (char __user *) arg;
677 		if (infobuf == NULL) {
678 			read_cpu = 0;
679 		}else {
680 			get_user(read_cpu, infobuf);
681 		}
682 
683 		/* Save the command for use when reading. */
684 		file->private_data = (void *)(long)cmd;
685 		break;
686 
687 	default:
688 		return -EINVAL;
689 	}
690 
691 	return 0;
692 }
693 
694 /* Function Description: open device. Mapped to user open().
695  * Return: Always 0.
696  */
697 static int
698 envctrl_open(struct inode *inode, struct file *file)
699 {
700 	file->private_data = NULL;
701 	return 0;
702 }
703 
704 /* Function Description: Open device. Mapped to user close().
705  * Return: Always 0.
706  */
707 static int
708 envctrl_release(struct inode *inode, struct file *file)
709 {
710 	return 0;
711 }
712 
713 static const struct file_operations envctrl_fops = {
714 	.owner =		THIS_MODULE,
715 	.read =			envctrl_read,
716 	.unlocked_ioctl =	envctrl_ioctl,
717 #ifdef CONFIG_COMPAT
718 	.compat_ioctl =		envctrl_ioctl,
719 #endif
720 	.open =			envctrl_open,
721 	.release =		envctrl_release,
722 	.llseek =		noop_llseek,
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 			    const 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, struct device_node *dp)
770 {
771 	int i = 0, len;
772 	const char *pos;
773 	const unsigned int *pval;
774 
775 	/* Firmware describe channels into a stream separated by a '\0'. */
776 	pos = of_get_property(dp, "channels-description", &len);
777 
778 	while (len > 0) {
779 		int l = strlen(pos) + 1;
780 		envctrl_set_mon(pchild, pos, i++);
781 		len -= l;
782 		pos += l;
783 	}
784 
785 	/* Get optional properties. */
786 	pval = of_get_property(dp, "warning-temp", NULL);
787 	if (pval)
788 		warning_temperature = *pval;
789 
790 	pval = of_get_property(dp, "shutdown-temp", NULL);
791 	if (pval)
792 		shutdown_temperature = *pval;
793 }
794 
795 /* Function Description: Initialize child device monitoring fan status.
796  * Return: None.
797  */
798 static void envctrl_init_fanstat(struct i2c_child_t *pchild)
799 {
800 	int i;
801 
802 	/* Go through all channels and set up the mask. */
803 	for (i = 0; i < pchild->total_chnls; i++)
804 		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
805 
806 	/* We only need to know if this child has fan status monitored.
807 	 * We don't care which channels since we have the mask already.
808 	 */
809 	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
810 }
811 
812 /* Function Description: Initialize child device for global addressing line.
813  * Return: None.
814  */
815 static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
816 {
817 	int i;
818 
819 	/* Voltage/PowerSupply monitoring is piggybacked
820 	 * with Global Address on CompactPCI.  See comments
821 	 * within envctrl_i2c_globaladdr for bit assignments.
822 	 *
823 	 * The mask is created here by assigning mask bits to each
824 	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
825 	 * Channel numbers are not consecutive within the globaladdr
826 	 * node (why?), so we use the actual counter value as chnls_mask
827 	 * index instead of the chnl_array[x].chnl_no value.
828 	 *
829 	 * NOTE: This loop could be replaced with a constant representing
830 	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
831 	 */
832 	for (i = 0; i < pchild->total_chnls; i++) {
833 		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
834 			pchild->voltage_mask |= chnls_mask[i];
835 		}
836 	}
837 
838 	/* We only need to know if this child has global addressing
839 	 * line monitored.  We don't care which channels since we know
840 	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
841 	 */
842 	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_MON;
843 }
844 
845 /* Initialize child device monitoring voltage status. */
846 static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
847 {
848 	int i;
849 
850 	/* Go through all channels and set up the mask. */
851 	for (i = 0; i < pchild->total_chnls; i++)
852 		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
853 
854 	/* We only need to know if this child has voltage status monitored.
855 	 * We don't care which channels since we have the mask already.
856 	 */
857 	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
858 }
859 
860 /* Function Description: Initialize i2c child device.
861  * Return: None.
862  */
863 static void envctrl_init_i2c_child(struct device_node *dp,
864 				   struct i2c_child_t *pchild)
865 {
866 	int len, i, tbls_size = 0;
867 	const void *pval;
868 
869 	/* Get device address. */
870 	pval = of_get_property(dp, "reg", &len);
871 	memcpy(&pchild->addr, pval, len);
872 
873 	/* Get tables property.  Read firmware temperature tables. */
874 	pval = of_get_property(dp, "translation", &len);
875 	if (pval && len > 0) {
876 		memcpy(pchild->tblprop_array, pval, len);
877                 pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
878 		for (i = 0; i < pchild->total_tbls; i++) {
879 			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
880 				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
881 			}
882 		}
883 
884                 pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
885 		if (pchild->tables == NULL){
886 			printk(KERN_ERR PFX "Failed to allocate table.\n");
887 			return;
888 		}
889 		pval = of_get_property(dp, "tables", &len);
890                 if (!pval || len <= 0) {
891 			printk(KERN_ERR PFX "Failed to get table.\n");
892 			return;
893 		}
894 		memcpy(pchild->tables, pval, len);
895 	}
896 
897 	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
898 	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
899 	 * "For Factory Use Only."
900 	 *
901 	 * We ignore the node on these platforms by assigning the
902 	 * 'NULL' monitor type.
903 	 */
904 	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
905 		struct device_node *root_node;
906 		int len;
907 
908 		root_node = of_find_node_by_path("/");
909 		if (!strcmp(root_node->name, "SUNW,UltraSPARC-IIi-cEngine")) {
910 			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
911 				pchild->mon_type[len] = ENVCTRL_NOMON;
912 			}
913 			return;
914 		}
915 	}
916 
917 	/* Get the monitor channels. */
918 	pval = of_get_property(dp, "channels-in-use", &len);
919 	memcpy(pchild->chnl_array, pval, len);
920 	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
921 
922 	for (i = 0; i < pchild->total_chnls; i++) {
923 		switch (pchild->chnl_array[i].type) {
924 		case PCF8584_TEMP_TYPE:
925 			envctrl_init_adc(pchild, dp);
926 			break;
927 
928 		case PCF8584_GLOBALADDR_TYPE:
929 			envctrl_init_globaladdr(pchild);
930 			i = pchild->total_chnls;
931 			break;
932 
933 		case PCF8584_FANSTAT_TYPE:
934 			envctrl_init_fanstat(pchild);
935 			i = pchild->total_chnls;
936 			break;
937 
938 		case PCF8584_VOLTAGE_TYPE:
939 			if (pchild->i2ctype == I2C_ADC) {
940 				envctrl_init_adc(pchild,dp);
941 			} else {
942 				envctrl_init_voltage_status(pchild);
943 			}
944 			i = pchild->total_chnls;
945 			break;
946 
947 		default:
948 			break;
949 		}
950 	}
951 }
952 
953 /* Function Description: Search the child device list for a device.
954  * Return : The i2c child if found. NULL otherwise.
955  */
956 static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
957 {
958 	int i, j;
959 
960 	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
961 		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
962 			if (i2c_childlist[i].mon_type[j] == mon_type) {
963 				return (struct i2c_child_t *)(&(i2c_childlist[i]));
964 			}
965 		}
966 	}
967 	return NULL;
968 }
969 
970 static void envctrl_do_shutdown(void)
971 {
972 	static int inprog = 0;
973 
974 	if (inprog != 0)
975 		return;
976 
977 	inprog = 1;
978 	printk(KERN_CRIT "kenvctrld: WARNING: Shutting down the system now.\n");
979 	orderly_poweroff(true);
980 }
981 
982 static struct task_struct *kenvctrld_task;
983 
984 static int kenvctrld(void *__unused)
985 {
986 	int poll_interval;
987 	int whichcpu;
988 	char tempbuf[10];
989 	struct i2c_child_t *cputemp;
990 
991 	if (NULL == (cputemp = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON))) {
992 		printk(KERN_ERR  PFX
993 		       "kenvctrld unable to monitor CPU temp-- exiting\n");
994 		return -ENODEV;
995 	}
996 
997 	poll_interval = 5000; /* TODO env_mon_interval */
998 
999 	printk(KERN_INFO PFX "%s starting...\n", current->comm);
1000 	for (;;) {
1001 		msleep_interruptible(poll_interval);
1002 
1003 		if (kthread_should_stop())
1004 			break;
1005 
1006 		for (whichcpu = 0; whichcpu < ENVCTRL_MAX_CPU; ++whichcpu) {
1007 			if (0 < envctrl_read_cpu_info(whichcpu, cputemp,
1008 						      ENVCTRL_CPUTEMP_MON,
1009 						      tempbuf)) {
1010 				if (tempbuf[0] >= shutdown_temperature) {
1011 					printk(KERN_CRIT
1012 						"%s: WARNING: CPU%i temperature %i C meets or exceeds "\
1013 						"shutdown threshold %i C\n",
1014 						current->comm, whichcpu,
1015 						tempbuf[0], shutdown_temperature);
1016 					envctrl_do_shutdown();
1017 				}
1018 			}
1019 		}
1020 	}
1021 	printk(KERN_INFO PFX "%s exiting...\n", current->comm);
1022 	return 0;
1023 }
1024 
1025 static int envctrl_probe(struct platform_device *op)
1026 {
1027 	struct device_node *dp;
1028 	int index, err;
1029 
1030 	if (i2c)
1031 		return -EINVAL;
1032 
1033 	i2c = of_ioremap(&op->resource[0], 0, 0x2, DRIVER_NAME);
1034 	if (!i2c)
1035 		return -ENOMEM;
1036 
1037 	index = 0;
1038 	dp = op->dev.of_node->child;
1039 	while (dp) {
1040 		if (!strcmp(dp->name, "gpio")) {
1041 			i2c_childlist[index].i2ctype = I2C_GPIO;
1042 			envctrl_init_i2c_child(dp, &(i2c_childlist[index++]));
1043 		} else if (!strcmp(dp->name, "adc")) {
1044 			i2c_childlist[index].i2ctype = I2C_ADC;
1045 			envctrl_init_i2c_child(dp, &(i2c_childlist[index++]));
1046 		}
1047 
1048 		dp = dp->sibling;
1049 	}
1050 
1051 	/* Set device address. */
1052 	writeb(CONTROL_PIN, i2c + PCF8584_CSR);
1053 	writeb(PCF8584_ADDRESS, i2c + PCF8584_DATA);
1054 
1055 	/* Set system clock and SCL frequencies. */
1056 	writeb(CONTROL_PIN | CONTROL_ES1, i2c + PCF8584_CSR);
1057 	writeb(CLK_4_43 | BUS_CLK_90, i2c + PCF8584_DATA);
1058 
1059 	/* Enable serial interface. */
1060 	writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, i2c + PCF8584_CSR);
1061 	udelay(200);
1062 
1063 	/* Register the device as a minor miscellaneous device. */
1064 	err = misc_register(&envctrl_dev);
1065 	if (err) {
1066 		printk(KERN_ERR PFX "Unable to get misc minor %d\n",
1067 		       envctrl_dev.minor);
1068 		goto out_iounmap;
1069 	}
1070 
1071 	/* Note above traversal routine post-incremented 'i' to accommodate
1072 	 * a next child device, so we decrement before reverse-traversal of
1073 	 * child devices.
1074 	 */
1075 	printk(KERN_INFO PFX "Initialized ");
1076 	for (--index; index >= 0; --index) {
1077 		printk("[%s 0x%lx]%s",
1078 			(I2C_ADC == i2c_childlist[index].i2ctype) ? "adc" :
1079 			((I2C_GPIO == i2c_childlist[index].i2ctype) ? "gpio" : "unknown"),
1080 			i2c_childlist[index].addr, (0 == index) ? "\n" : " ");
1081 	}
1082 
1083 	kenvctrld_task = kthread_run(kenvctrld, NULL, "kenvctrld");
1084 	if (IS_ERR(kenvctrld_task)) {
1085 		err = PTR_ERR(kenvctrld_task);
1086 		goto out_deregister;
1087 	}
1088 
1089 	return 0;
1090 
1091 out_deregister:
1092 	misc_deregister(&envctrl_dev);
1093 out_iounmap:
1094 	of_iounmap(&op->resource[0], i2c, 0x2);
1095 	for (index = 0; index < ENVCTRL_MAX_CPU * 2; index++)
1096 		kfree(i2c_childlist[index].tables);
1097 
1098 	return err;
1099 }
1100 
1101 static int envctrl_remove(struct platform_device *op)
1102 {
1103 	int index;
1104 
1105 	kthread_stop(kenvctrld_task);
1106 
1107 	of_iounmap(&op->resource[0], i2c, 0x2);
1108 	misc_deregister(&envctrl_dev);
1109 
1110 	for (index = 0; index < ENVCTRL_MAX_CPU * 2; index++)
1111 		kfree(i2c_childlist[index].tables);
1112 
1113 	return 0;
1114 }
1115 
1116 static const struct of_device_id envctrl_match[] = {
1117 	{
1118 		.name = "i2c",
1119 		.compatible = "i2cpcf,8584",
1120 	},
1121 	{},
1122 };
1123 MODULE_DEVICE_TABLE(of, envctrl_match);
1124 
1125 static struct platform_driver envctrl_driver = {
1126 	.driver = {
1127 		.name = DRIVER_NAME,
1128 		.of_match_table = envctrl_match,
1129 	},
1130 	.probe		= envctrl_probe,
1131 	.remove		= envctrl_remove,
1132 };
1133 
1134 module_platform_driver(envctrl_driver);
1135 
1136 MODULE_LICENSE("GPL");
1137