patch-2.2.16 linux/drivers/sbus/char/envctrl.c

• Lines: 1124
• Date: Wed Jun 7 14:26:43 2000
• Orig file: v2.2.15/linux/drivers/sbus/char/envctrl.c
• Orig date: Mon Nov 16 10:37:28 1998

diff -urN v2.2.15/linux/drivers/sbus/char/envctrl.c linux/drivers/sbus/char/envctrl.c
@@ -1,7 +1,17 @@
-/* $Id: envctrl.c,v 1.9 1998/11/06 07:38:20 ecd Exp $
+/* $Id: envctrl.c,v 1.9.2.1 2000/05/02 04:23:33 davem Exp $
  * envctrl.c: Temperature and Fan monitoring on Machines providing it.
  *
  * Copyright (C) 1998  Eddie C. Dost  (ecd@skynet.be)
+ * Copyright (C) 2000  Vinh Truong    (vinh.truong@eng.sun.com)
+ * VT - The implementation is to support Sun Microelectronics (SME) platform
+ *      environment monitoring.  SME platforms use pcf8584 as the i2c bus 
+ *      controller to access pcf8591 (8-bit A/D and D/A converter) and 
+ *      pcf8571 (256 x 8-bit static low-voltage RAM with I2C-bus interface).
+ *      At board level, it follows SME Firmware I2C Specification. Reference:
+ * 	http://www-eu2.semiconductors.com/pip/PCF8584P
+ * 	http://www-eu2.semiconductors.com/pip/PCF8574AP
+ * 	http://www-eu2.semiconductors.com/pip/PCF8591P
+ * 
  */
 
 #include <linux/config.h>
@@ -12,6 +22,8 @@
 #include <linux/ioport.h>
 #include <linux/init.h>
 #include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/malloc.h>
 
 #include <asm/ebus.h>
 #include <asm/uaccess.h>
@@ -19,10 +31,8 @@
 
 #define ENVCTRL_MINOR	162
 
-
 #undef DEBUG_BUS_SCAN
 
-
 #define PCF8584_ADDRESS	0x55
 
 #define CONTROL_PIN	0x80
@@ -57,229 +67,599 @@
 #define CLK_8		0x18
 #define CLK_12		0x1c
 
+#define OBD_SEND_START	0xc5    /* value to generate I2c_bus START condition */
+#define OBD_SEND_STOP 	0xc3    /* value to generate I2c_bus STOP condition */
 
-#define I2C_WRITE	0x00
-#define I2C_READ	0x01
+/* Monitor type of i2c child device.
+ * Firmware definitions.
+ */
+#define PCF8584_MAX_CHANNELS            8
+#define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
+#define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
+#define PCF8584_TEMP_TYPE	        1  /* temperature monitor*/
 
-struct pcf8584_reg
-{
-	__volatile__ unsigned char data;
-	__volatile__ unsigned char csr;
-};
+/* Monitor type of i2c child device.
+ * Driver definitions.
+ */
+#define ENVCTRL_NOMON			0
+#define ENVCTRL_CPUTEMP_MON		1    /* cpu temperature monitor */
+#define ENVCTRL_CPUVOLTAGE_MON	  	2    /* voltage monitor         */
+#define ENVCTRL_FANSTAT_MON  		3    /* fan status monitor      */
+#define ENVCTRL_ETHERTEMP_MON		4    /* ethernet temperarture */
+					     /* monitor                     */
+#define ENVCTRL_VOLTAGESTAT_MON	  	5    /* voltage status monitor  */
+#define ENVCTRL_MTHRBDTEMP_MON		6    /* motherboard temperature */
+#define ENVCTRL_SCSITEMP_MON		7    /* scsi temperarture */
 
-static struct pcf8584_reg *i2c;
+/* Child device type.
+ * Driver definitions.
+ */
+#define I2C_ADC				0    /* pcf8591 */
+#define I2C_GPIO			1    /* pcf8571 */
 
+/* Data read from child device may need to decode
+ * through a data table and a scale.
+ * Translation type as defined by firmware.
+ */
+#define ENVCTRL_TRANSLATE_NO		0
+#define ENVCTRL_TRANSLATE_PARTIAL	1
+#define ENVCTRL_TRANSLATE_COMBINED	2
+#define ENVCTRL_TRANSLATE_FULL		3     /* table[data] */
+#define ENVCTRL_TRANSLATE_SCALE		4     /* table[data]/scale */
+
+/* Driver miscellaneous definitions. */
+#define ENVCTRL_MAX_CPU			4
+#define CHANNEL_DESC_SZ			256
+
+struct pcf8584_reg {
+	 unsigned char data;
+	 unsigned char csr;
+};
 
-#ifdef DEBUG_BUS_SCAN
-struct i2c_addr_map {
-	unsigned char addr;
-	unsigned char mask;
-	char *name;
+/* Each child device can be monitored by up to PCF8584_MAX_CHANNELS.
+ * Property of a port or channel as defined by the firmware.
+ */
+struct pcf8584_channel {
+        unsigned char chnl_no;
+        unsigned char io_direction;
+        unsigned char type;
+        unsigned char last;
 };
 
-static struct i2c_addr_map devmap[] = {
-	{ 0x38, 0x78, "PCF8574A" },
-	{ 0x20, 0x78, "TDA8444" },
-	{ 0x48, 0x78, "PCF8591" },
+/* Each child device may have one or more tables of bytes to help decode
+ * data. Table property as defined by the firmware.
+ */ 
+struct pcf8584_tblprop {
+        unsigned int type;
+        unsigned int scale;  
+        unsigned int offset; /* offset from the beginning of the table */
+        unsigned int size;
 };
-#define NR_DEVMAP (sizeof(devmap) / sizeof(devmap[0]))
-#endif
 
-static __inline__ int
-PUT_DATA(__volatile__ unsigned char *data, char *buffer, int user)
+/* i2c child */
+struct i2c_child_t {
+	/* Either ADC or GPIO. */
+	unsigned char i2ctype;
+        unsigned long addr;    
+        struct pcf8584_channel chnl_array[PCF8584_MAX_CHANNELS];
+
+	/* Channel info. */ 
+	unsigned int total_chnls;	/* Number of monitor channels. */
+	unsigned char fan_mask;		/* Byte mask for fan status channels. */
+	unsigned char voltage_mask;	/* Byte mask for voltage status channels. */
+        struct pcf8584_tblprop tblprop_array[PCF8584_MAX_CHANNELS];
+
+	/* Properties of all monitor channels. */
+	unsigned int total_tbls;	/* Number of monitor tables. */
+        char *tables;			/* Pointer to table(s). */
+	char chnls_desc[CHANNEL_DESC_SZ]; /* Channel description. */
+	char mon_type[PCF8584_MAX_CHANNELS];
+};
+
+static struct pcf8584_reg *i2c = NULL;
+static struct i2c_child_t i2c_childlist[ENVCTRL_MAX_CPU*2];
+static unsigned char chnls_mask[] = { 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80 };
+static unsigned int warning_temperature = 0;
+static unsigned int shutdown_temperature = 0;
+static char read_cpu;
+
+/* Forward declarations. */
+static struct i2c_child_t *envctrl_get_i2c_child(unsigned char);
+
+/* Function description: Read a byte from an i2c controller register.
+ * Return: A byte from the passed in address.
+ */
+static inline unsigned char envctrl_readb(unsigned char *p)
 {
-	if (user) {
-		if (put_user(*data, buffer))
-			return -EFAULT;
-	} else {
-		*buffer = *data;
-	}
-	return 0;
+	unsigned char result;
+
+	__asm__ __volatile__("lduba [%1] %2, %0"
+			     : "=r" (result)
+			     : "r" (p), "i" (ASI_PHYS_BYPASS_EC_E));
+	return result;
 }
 
-static __inline__ int
-GET_DATA(__volatile__ unsigned char *data, const char *buffer, int user)
+/* Function description: Write a byte to an i2c controller register.
+ * Return: Nothing.
+ */
+static inline void envctrl_writeb(unsigned char val, unsigned char *p)
 {
-	if (user) {
-		if (get_user(*data, buffer))
-			return -EFAULT;
-	} else {
-		*data = *buffer;
-	}
-	return 0;
+	__asm__ __volatile__("stba %0, [%1] %2"
+			     : /* no outputs */
+			     : "r" (val), "r" (p), "i" (ASI_PHYS_BYPASS_EC_E));
 }
 
-static int
-i2c_read(unsigned char dev, char *buffer, int len, int user)
+/* Function Description: Test the PIN bit (Pending Interrupt Not) 
+ * 			 to test when serial transmission is completed .
+ * Return : None.
+ */
+static void envtrl_i2c_test_pin(void)
 {
-	unsigned char dummy;
-	unsigned char stat;
-	int error = -ENODEV;
-	int count = 0;
+	int limit = 1000000;
 
-	i2c->data = (dev << 1) | I2C_READ;
-
-	while (!(i2c->csr & STATUS_BB))
+	while (--limit > 0) {
+		if(!(envctrl_readb(&i2c->csr) & STATUS_PIN)) 
+			break;
 		udelay(1);
+	} 
 
-	i2c->csr = CONTROL_PIN | CONTROL_ES0 | CONTROL_STA | CONTROL_ACK;
+	if (limit <= 0)
+		printk(KERN_INFO "envctrl: Pin status will not clear.\n");
+}
 
-	do {
+/* Function Description: Test busy bit.
+ * Return : None.
+ */
+static void envctrl_i2c_test_bb(void)
+{
+	int limit = 1000000;
+
+	while (--limit > 0) {
+		/* Busy bit 0 means busy. */
+		if (envctrl_readb(&i2c->csr) & STATUS_BB)
+			break;
 		udelay(1);
-		while ((stat = i2c->csr) & STATUS_PIN)
-			udelay(1);
+	} 
+
+	if (limit <= 0)
+		printk(KERN_INFO "envctrl: Busy bit will not clear.\n");
+}
 
-		if (stat & STATUS_LRB)
-			goto stop;
+/* Function Description: Send the adress for a read access.
+ * Return : 0 if not acknowledged, otherwise acknowledged.
+ */
+static int envctrl_i2c_read_addr(unsigned char addr)
+{
+	envctrl_i2c_test_bb();
 
-		error = 0;
-		if (len == 0) {
-			count--;
-			break;
-		}
+	/* Load address. */
+	envctrl_writeb(addr + 1, &i2c->data);
 
-		if (count == (len - 1))
-			break;
+	envctrl_i2c_test_bb();
 
-		if (count++ > 0) {
-			error = PUT_DATA(&i2c->data, buffer++, user);
-			if (error)
-				break;
-		} else
-			dummy = i2c->data;
-	} while (1);
-
-	i2c->csr = CONTROL_ES0;
-	if (!error && (count++ > 0))
-		error = PUT_DATA(&i2c->data, buffer++, user);
-	else
-		dummy = i2c->data;
+	envctrl_writeb(OBD_SEND_START, &i2c->csr);
 
-	udelay(1);
-	while ((stat = i2c->csr) & STATUS_PIN)
-		udelay(1);
+	/* Wait for PIN. */
+	envtrl_i2c_test_pin();
 
-stop:
-	i2c->csr = CONTROL_PIN | CONTROL_ES0 | CONTROL_STO | CONTROL_ACK;
-	if (!error && (count++ > 0))
-		error = PUT_DATA(&i2c->data, buffer++, user);
-	else
-		dummy = i2c->data;
-
-	if (error)
-		return error;
-	return count - 1;
+	/* CSR 0 means acknowledged. */
+	if (!(envctrl_readb(&i2c->csr) & STATUS_LRB)) {
+		return envctrl_readb(&i2c->data);
+	} else {
+		envctrl_writeb(OBD_SEND_STOP, &i2c->csr);
+		return 0;
+	}
 }
 
-static int
-i2c_write(unsigned char dev, const char *buffer, int len, int user)
+/* Function Description: Send the adress for write mode.  
+ * Return : None.
+ */
+static void envctrl_i2c_write_addr(unsigned char addr)
 {
-	int error = -ENODEV;
-	int count = 0;
+	envctrl_i2c_test_bb();
+	envctrl_writeb(addr, &i2c->data);
 
-	while (!(i2c->csr & STATUS_BB))
-		udelay(1);
+	/* Generate Start condition. */
+	envctrl_writeb(OBD_SEND_START, &i2c->csr);
+}
 
-	i2c->data = (dev << 1) | I2C_WRITE;
-	i2c->csr = CONTROL_PIN | CONTROL_ES0 | CONTROL_STA | CONTROL_ACK;
+/* Function Description: Read 1 byte of data from addr 
+ *			 set by envctrl_i2c_read_addr() 
+ * Return : Data from address set by envctrl_i2c_read_addr().
+ */
+static unsigned char envctrl_i2c_read_data(void)
+{
+	envtrl_i2c_test_pin();
+	envctrl_writeb(CONTROL_ES0, &i2c->csr);  /* Send neg ack. */
+	return envctrl_readb(&i2c->data);
+}
 
-	do {
-		unsigned char stat;
+/* Function Description: Instruct the device which port to read data from.  
+ * Return : None.
+ */
+static void envctrl_i2c_write_data(unsigned char port)
+{
+	envtrl_i2c_test_pin();
+	envctrl_writeb(port, &i2c->data);
+}
 
-		udelay(1);
-		while ((stat = i2c->csr) & STATUS_PIN)
-			udelay(1);
+/* Function Description: Generate Stop condition after last byte is sent.
+ * Return : None.
+ */
+static void envctrl_i2c_stop(void)
+{
+	envtrl_i2c_test_pin();
+	envctrl_writeb(OBD_SEND_STOP, &i2c->csr);
+}
 
-		if (stat & STATUS_LRB)
-			break;
+/* Function Description: Read adc device.
+ * Return : Data at address and port.
+ */
+static unsigned char envctrl_i2c_read_8591(unsigned char addr, unsigned char port)
+{
+	/* Send address. */
+	envctrl_i2c_write_addr(addr);
 
-		error = count;
-		if (count == len)
-			break;
+	/* Setup port to read. */
+	envctrl_i2c_write_data(port);
+	envctrl_i2c_stop();
 
-		error = GET_DATA(&i2c->data, buffer++, user);
-		if (error)
-			break;
+	/* Read port. */
+	envctrl_i2c_read_addr(addr);
 
-		count++;
-	} while (1);
+	/* Do a single byte read and send stop. */
+	envctrl_i2c_read_data();
+	envctrl_i2c_stop();
 
-	i2c->csr = CONTROL_PIN | CONTROL_ES0 | CONTROL_STO | CONTROL_ACK;
-	return error;
+	return envctrl_readb(&i2c->data);
 }
 
-__initfunc(static int i2c_scan_bus(void))
+/* Function Description: Read gpio device.
+ * Return : Data at address.
+ */
+static unsigned char envctrl_i2c_read_8574(unsigned char addr)
 {
-	unsigned char dev;
-	int count = 0;
-
-	for (dev = 1; dev < 128; dev++) {
-		if (i2c_read(dev, 0, 0, 0) == 0) {
-#ifdef DEBUG_BUS_SCAN
-			int i;
-			for (i = 0; i < NR_DEVMAP; i++)
-				if ((dev & devmap[i].mask) == devmap[i].addr)
-					break;
-			printk("envctrl: i2c device at %02x: %s\n", dev,
-			       i < NR_DEVMAP ? devmap[i].name : "unknown");
-#endif
-			count++;
+	unsigned char rd;
+
+	envctrl_i2c_read_addr(addr);
+
+	/* Do a single byte read and send stop. */
+	rd = envctrl_i2c_read_data();
+	envctrl_i2c_stop();
+
+	return rd;
+}
+
+/* Function Description: Decode data read from an adc device using firmware
+ *                       table.
+ * Return: Number of read bytes. Data is stored in bufdata in ascii format.
+ */
+static int envctrl_i2c_data_translate(unsigned char data, int translate_type,
+				      int scale, char *tbl, char *bufdata)
+{
+	int len = 0;
+
+	switch (translate_type) {
+	case ENVCTRL_TRANSLATE_NO:
+		/* No decode necessary. */
+		len = 1;
+		bufdata[0] = data;
+		break;
+
+	case ENVCTRL_TRANSLATE_FULL:
+		/* Decode this way: data = table[data]. */
+		len = 1;
+		bufdata[0] = tbl[data];
+		break;
+
+	case ENVCTRL_TRANSLATE_SCALE:
+		/* Decode this way: data = table[data]/scale */
+		sprintf(bufdata,"%d ", (tbl[data] * 10) / (scale));
+		len = strlen(bufdata);
+		bufdata[len - 1] = bufdata[len - 2];
+		bufdata[len - 2] = '.';
+		break;
+
+	default:
+		break;
+	};
+
+	return len;
+}
+
+/* Function Description: Read cpu-related data such as cpu temperature, voltage.
+ * Return: Number of read bytes. Data is stored in bufdata in ascii format.
+ */
+static int envctrl_read_cpu_info(struct i2c_child_t *pchild,
+				 char mon_type, unsigned char *bufdata)
+{
+	unsigned char data;
+	int i;
+	char *tbl, j = -1;
+
+	/* Find the right monitor type and channel. */
+	for (i = 0; i< PCF8584_MAX_CHANNELS; i++) {
+		if (pchild->mon_type[i] == mon_type) {
+			if (++j == read_cpu) {
+				break;
+			}
 		}
 	}
-	if (!count) {
-		printk("%s: no devices found\n", __FUNCTION__);
-		return -ENODEV;
-	}
-	return 0;
+
+	if (j != read_cpu)
+		return 0;
+
+        /* Read data from address and port. */
+	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
+				     (unsigned char)pchild->chnl_array[i].chnl_no);
+
+	/* Find decoding table. */
+	tbl = pchild->tables + pchild->tblprop_array[i].offset;
+
+	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
+					  pchild->tblprop_array[i].scale,
+					  tbl, bufdata);
 }
 
-static loff_t
-envctrl_llseek(struct file *file, loff_t offset, int type)
+/* Function Description: Read noncpu-related data such as motherboard 
+ *                       temperature.
+ * Return: Number of read bytes. Data is stored in bufdata in ascii format.
+ */
+static int envctrl_read_noncpu_info(struct i2c_child_t *pchild,
+				    char mon_type, unsigned char *bufdata)
 {
-	return -ESPIPE;
+	unsigned char data;
+	int i;
+	char *tbl = NULL;
+
+	for (i = 0; i< PCF8584_MAX_CHANNELS; i++) {
+		if (pchild->mon_type[i] == mon_type) {
+			break;
+		}
+	}
+
+	if (i >= PCF8584_MAX_CHANNELS)
+		return 0;
+
+        /* Read data from address and port. */
+	data = envctrl_i2c_read_8591((unsigned char)pchild->addr,
+				     (unsigned char)pchild->chnl_array[i].chnl_no);
+
+	/* Find decoding table. */
+	tbl = pchild->tables + pchild->tblprop_array[i].offset;
+
+	return envctrl_i2c_data_translate(data, pchild->tblprop_array[i].type,
+					  pchild->tblprop_array[i].scale,
+					  tbl, bufdata);
 }
 
-static ssize_t
-envctrl_read(struct file *file, char *buf, size_t count, loff_t *ppos)
-{
-	unsigned long addr = (unsigned long)file->private_data;
+/* Function Description: Read fan status.
+ * Return : Always 1 byte. Status stored in bufdata.
+ */
+static int envctrl_i2c_fan_status(struct i2c_child_t *pchild,
+				  unsigned char data,
+				  char *bufdata)
+{
+	unsigned char tmp, ret = 0;
+	int i, j = 0;
+
+	tmp = data & pchild->fan_mask;
+
+	if (tmp == pchild->fan_mask) {
+		/* All bits are on. All fans are functioning. */
+		ret = ENVCTRL_ALL_FANS_GOOD;
+	} else if (tmp == 0) {
+		/* No bits are on. No fans are functioning. */
+		ret = ENVCTRL_ALL_FANS_BAD;
+	} else {
+		/* Go through all channels, mark 'on' the matched bits.
+		 * Notice that fan_mask may have discontiguous bits but
+		 * return mask are always contiguous. For example if we
+		 * monitor 4 fans at channels 0,1,2,4, the return mask
+		 * should be 00010000 if only fan at channel 4 is working.
+		 */
+		for (i = 0; i < PCF8584_MAX_CHANNELS;i++) {
+			if (pchild->fan_mask & chnls_mask[i]) {
+				if (!(chnls_mask[i] & tmp)) {
+					ret |= chnls_mask[j];
+				}
+				j++;
+			}
+		}
+	}
 
-	return i2c_read(addr, buf, count, 1);
+	bufdata[0] = ret;
+	return 1;
 }
 
+/* Function Description: Read voltage and power supply status.
+ * Return : Always 1 byte. Status stored in bufdata.
+ */
+static unsigned char envctrl_i2c_voltage_status(struct i2c_child_t *pchild,
+						unsigned char data,
+						char *bufdata)
+{
+	unsigned char tmp, ret = 0;
+	int i, j = 0;
+
+	tmp = data & pchild->voltage_mask;
+
+	/* Two channels are used to monitor voltage and power supply. */
+	if (tmp == pchild->voltage_mask) {
+		/* All bits are on. Voltage and power supply are okay. */
+		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_GOOD;
+	} else if (tmp == 0) {
+		/* All bits are off. Voltage and power supply are bad */
+		ret = ENVCTRL_VOLTAGE_POWERSUPPLY_BAD;
+	} else {
+		/* Either voltage or power supply has problem. */
+		for (i = 0; i < PCF8584_MAX_CHANNELS; i++) {
+			if (pchild->voltage_mask & chnls_mask[i]) {
+				j++;
+
+				/* Break out when there is a mismatch. */
+				if (!(chnls_mask[i] & tmp))
+					break; 
+			}
+		}
+
+		/* Make a wish that hardware will always use the
+		 * first channel for voltage and the second for
+		 * power supply.
+		 */
+		if (j == 1)
+			ret = ENVCTRL_VOLTAGE_BAD;
+		else
+			ret = ENVCTRL_POWERSUPPLY_BAD;
+	}
+
+	bufdata[0] = ret;
+	return 1;
+}
+
+/* Function Description: Read a byte from /dev/envctrl. Mapped to user read().
+ * Return: Number of read bytes. 0 for error.
+ */
 static ssize_t
-envctrl_write(struct file *file, const char *buf, size_t count, loff_t *ppos)
+envctrl_read(struct file *file, char *buf, size_t count, loff_t *ppos)
 {
-	unsigned long addr = (unsigned long)file->private_data;
+	struct i2c_child_t *pchild;
+	unsigned char data[10];
+	int ret = 0;
+
+	/* Get the type of read as decided in ioctl() call.
+	 * Find the appropriate i2c child.
+	 * Get the data and put back to the user buffer.
+	 */
+
+	switch ((int)(long)file->private_data) {
+	case ENVCTRL_RD_WARNING_TEMPERATURE:
+		if (warning_temperature == 0)
+			return 0;
+
+		data[0] = (unsigned char)(warning_temperature);
+		ret = 1;
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
+		if (shutdown_temperature == 0)
+			return 0;
+
+		data[0] = (unsigned char)(shutdown_temperature);
+		ret = 1;
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
+		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_MTHRBDTEMP_MON)))
+			return 0;
+		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_MTHRBDTEMP_MON, data);
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_CPU_TEMPERATURE:
+		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUTEMP_MON)))
+			return 0;
+		ret = envctrl_read_cpu_info(pchild, ENVCTRL_CPUTEMP_MON, data);
+
+		/* Reset cpu to the default cpu0. */
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_CPU_VOLTAGE:
+		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_CPUVOLTAGE_MON)))
+			return 0;
+		ret = envctrl_read_cpu_info(pchild, ENVCTRL_CPUVOLTAGE_MON, data);
+
+		/* Reset cpu to the default cpu0. */
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_SCSI_TEMPERATURE:
+		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_SCSITEMP_MON)))
+			return 0;
+		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_SCSITEMP_MON, data);
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
+		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_ETHERTEMP_MON)))
+			return 0;
+		ret = envctrl_read_noncpu_info(pchild, ENVCTRL_ETHERTEMP_MON, data);
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_FAN_STATUS:
+		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_FANSTAT_MON)))
+			return 0;
+		data[0] = envctrl_i2c_read_8574(pchild->addr);
+		ret = envctrl_i2c_fan_status(pchild,data[0], data);
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	case ENVCTRL_RD_VOLTAGE_STATUS:
+		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_VOLTAGESTAT_MON)))
+			return 0;
+		data[0] = envctrl_i2c_read_8574(pchild->addr);
+		ret = envctrl_i2c_voltage_status(pchild, data[0], data);
+		copy_to_user((unsigned char*)buf, data, ret);
+		break;
+
+	default:
+		break;
+
+	};
 
-	return i2c_write(addr, buf, count, 1);
+	return ret;
 }
 
+/* Function Description: Command what to read.  Mapped to user ioctl().
+ * Return: Gives 0 for implemented commands, -EINVAL otherwise.
+ */
 static int
 envctrl_ioctl(struct inode *inode, struct file *file,
 	      unsigned int cmd, unsigned long arg)
 {
-	unsigned long data;
-	int addr;
+	char *infobuf;
 
 	switch (cmd) {
-		case I2CIOCSADR:
-			if (get_user(addr, (int *)arg))
-				return -EFAULT;
-			data = addr & 0x7f;
-			file->private_data = (void *)data;
-			break;
-		case I2CIOCGADR:
-			addr = (unsigned long)file->private_data;
-			if (put_user(addr, (int *)arg))
-				return -EFAULT;
-			break;
-		default:
-			return -EINVAL;
-	}
+	case ENVCTRL_RD_WARNING_TEMPERATURE:
+	case ENVCTRL_RD_SHUTDOWN_TEMPERATURE:
+	case ENVCTRL_RD_MTHRBD_TEMPERATURE:
+	case ENVCTRL_RD_FAN_STATUS:
+	case ENVCTRL_RD_VOLTAGE_STATUS:
+	case ENVCTRL_RD_ETHERNET_TEMPERATURE:
+	case ENVCTRL_RD_SCSI_TEMPERATURE:
+		file->private_data = (void *)(long)cmd;
+		break;
+
+	case ENVCTRL_RD_CPU_TEMPERATURE:
+	case ENVCTRL_RD_CPU_VOLTAGE:
+		/* Check to see if application passes in any cpu number,
+		 * the default is cpu0.
+		 */
+		infobuf = (char *) arg;
+		if (infobuf == NULL) {
+			read_cpu = 0;
+		}else {
+			get_user(read_cpu, infobuf);
+		}
+
+		/* Save the command for use when reading. */
+		file->private_data = (void *)(long)cmd;
+		break;
+
+	default:
+		return -EINVAL;
+	};
+
 	return 0;
 }
 
+/* Function Description: open device. Mapped to user open().
+ * Return: Always 0.
+ */
 static int
 envctrl_open(struct inode *inode, struct file *file)
 {
@@ -288,6 +668,9 @@
 	return 0;
 }
 
+/* Function Description: Open device. Mapped to user close().
+ * Return: Always 0.
+ */
 static int
 envctrl_release(struct inode *inode, struct file *file)
 {
@@ -296,11 +679,11 @@
 }
 
 static struct file_operations envctrl_fops = {
-	envctrl_llseek,
+	NULL,
 	envctrl_read,
-	envctrl_write,
+	NULL,
 	NULL,		/* readdir */
-	NULL,		/* poll */	
+	NULL,		/* poll */
 	envctrl_ioctl,
 	NULL,		/* mmap */
 	envctrl_open,
@@ -314,6 +697,189 @@
 	&envctrl_fops
 };
 
+/* Function Description: Set monitor type based on firmware description.
+ * Return: None.
+ */
+static void envctrl_set_mon(struct i2c_child_t *pchild,
+			    char *chnl_desc,
+			    int chnl_no)
+{
+	/* Firmware only has temperature type.  It does not distinguish
+	 * different kinds of temperatures.  We use channel description
+	 * to disinguish them.
+	 */
+	if (!(strcmp(chnl_desc,"temp,cpu")) ||
+	    !(strcmp(chnl_desc,"temp,cpu0")) ||
+	    !(strcmp(chnl_desc,"temp,cpu1")) ||
+	    !(strcmp(chnl_desc,"temp,cpu2")) ||
+	    !(strcmp(chnl_desc,"temp,cpu3")))
+		pchild->mon_type[chnl_no] = ENVCTRL_CPUTEMP_MON;
+
+	if (!(strcmp(chnl_desc,"vddcore,cpu0")) ||
+	    !(strcmp(chnl_desc,"vddcore,cpu1")) ||
+	    !(strcmp(chnl_desc,"vddcore,cpu2")) ||
+	    !(strcmp(chnl_desc,"vddcore,cpu3")))
+		pchild->mon_type[chnl_no] = ENVCTRL_CPUVOLTAGE_MON;
+
+	if (!(strcmp(chnl_desc,"temp,motherboard")))
+		pchild->mon_type[chnl_no] = ENVCTRL_MTHRBDTEMP_MON;
+
+	if (!(strcmp(chnl_desc,"temp,scsi")))
+		pchild->mon_type[chnl_no] = ENVCTRL_SCSITEMP_MON;
+
+	if (!(strcmp(chnl_desc,"temp,ethernet")))
+		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
+
+	if (!(strcmp(chnl_desc,"temp,ethernet")))
+		pchild->mon_type[chnl_no] = ENVCTRL_ETHERTEMP_MON;
+}
+
+/* Function Description: Initialize monitor channel with channel desc,
+ *                       decoding tables, monitor type, optional properties.
+ * Return: None.
+ */
+static void envctrl_init_adc(struct i2c_child_t *pchild, int node)
+{
+	char chnls_desc[CHANNEL_DESC_SZ];
+	int i, len, j = 0;
+	char *ptr;
+
+	/* Firmware describe channels into a stream separated by a '\0'.
+	 * Replace all '\0' with a space.
+	 */
+        len = prom_getproperty(node, "channels-description", chnls_desc,
+			       CHANNEL_DESC_SZ);
+        for (i = 0; i < len; i++) {
+                if (chnls_desc[i] == '\0')
+                        chnls_desc[i] = ' ';
+        }
+
+	ptr = strtok(chnls_desc, " ");
+	while (ptr != NULL) {
+		envctrl_set_mon(pchild, ptr, j);
+		ptr = strtok(NULL, " ");
+		j++;
+	}
+
+	/* Get optional properties. */
+        len = prom_getproperty(node, "warning-temp", (char *)&warning_temperature,
+			       sizeof(warning_temperature));
+        len = prom_getproperty(node, "shutdown-temp", (char *)&shutdown_temperature,
+			       sizeof(shutdown_temperature));
+}
+
+/* Function Description: Initialize child device monitoring fan status.
+ * Return: None.
+ */
+static void envctrl_init_fanstat(struct i2c_child_t *pchild)
+{
+	int i;
+
+	/* Go through all channels and set up the mask. */
+	for (i = 0; i < pchild->total_chnls; i++)
+		pchild->fan_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
+
+	/* We only need to know if this child has fan status monitored.
+	 * We dont care which channels since we have the mask already.
+	 */
+	pchild->mon_type[0] = ENVCTRL_FANSTAT_MON;
+}
+
+/* Initialize child device monitoring voltage status. */
+static void envctrl_init_voltage_status(struct i2c_child_t *pchild)
+{
+	int i;
+
+	/* Go through all channels and set up the mask. */
+	for (i = 0; i < pchild->total_chnls; i++)
+		pchild->voltage_mask |= chnls_mask[(pchild->chnl_array[i]).chnl_no];
+
+	/* We only need to know if this child has voltage status monitored.
+	 * We dont care which channels since we have the mask already.
+	 */
+	pchild->mon_type[0] = ENVCTRL_VOLTAGESTAT_MON;
+}
+
+/* Function Description: Initialize i2c child device.
+ * Return: None.
+ */
+static void envctrl_init_i2c_child(struct linux_ebus_child *edev_child,
+				   struct i2c_child_t *pchild)
+{
+	int node, len, i, tbls_size = 0;
+
+	node = edev_child->prom_node;
+
+	/* Get device address. */
+	len = prom_getproperty(node, "reg", (char *)&(pchild->addr), sizeof(pchild->addr));
+
+	/* Get tables property.  Read firmware temperature tables. */
+	len = prom_getproperty(node, "translation", (char *)pchild->tblprop_array,
+			       PCF8584_MAX_CHANNELS*sizeof(struct pcf8584_tblprop));
+	if (len > 0) {
+                pchild->total_tbls = len / sizeof(struct pcf8584_tblprop);
+		for (i = 0; i < pchild->total_tbls; i++) {
+			if ((pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset) > tbls_size) {
+				tbls_size = pchild->tblprop_array[i].size + pchild->tblprop_array[i].offset;
+			}
+		}
+
+                pchild->tables = kmalloc(tbls_size, GFP_KERNEL);
+                len = prom_getproperty(node, "tables", (char *)pchild->tables, tbls_size);
+                if (len <= 0) {
+			printk("envctrl: Failed to get table.\n");
+			return;
+		}
+	}
+
+	/* Get the monitor channels. */
+	len = prom_getproperty(node, "channels-in-use", (char *)pchild->chnl_array,
+			       PCF8584_MAX_CHANNELS*sizeof(struct pcf8584_channel));
+	pchild->total_chnls = len / sizeof(struct pcf8584_channel);
+
+	for (i = 0; i < pchild->total_chnls; i++) {
+		switch (pchild->chnl_array[i].type) {
+		case PCF8584_TEMP_TYPE:
+			envctrl_init_adc(pchild, node);
+			break;
+
+		case PCF8584_FANSTAT_TYPE:
+			envctrl_init_fanstat(pchild);
+			i = pchild->total_chnls;
+			break;
+
+		case PCF8584_VOLTAGE_TYPE:
+			if (pchild->i2ctype == I2C_ADC) {
+				envctrl_init_adc(pchild,node);
+			} else {
+				envctrl_init_voltage_status(pchild);
+			}
+			i = pchild->total_chnls;
+			break;
+
+		default:
+			break;
+		};
+	}
+}
+
+/* Function Description: Search the child device list for a device.
+ * Return : The i2c child if found. NULL otherwise.
+ */
+static struct i2c_child_t *envctrl_get_i2c_child(unsigned char mon_type)
+{
+	int i, j;
+
+	for (i = 0; i < ENVCTRL_MAX_CPU*2; i++) {
+		for (j = 0; j < PCF8584_MAX_CHANNELS; j++) {
+			if ( i2c_childlist[i].mon_type[j] == mon_type) {
+				return (struct i2c_child_t*)(&(i2c_childlist[i]));
+			}
+		}
+	}
+	return NULL;
+}
+
 #ifdef MODULE
 int init_module(void)
 #else
@@ -321,61 +887,77 @@
 #endif
 {
 #ifdef CONFIG_PCI
-	struct linux_ebus *ebus;
-	struct linux_ebus_device *edev = 0;
-	int err;
-
+	struct linux_ebus *ebus = NULL;
+	struct linux_ebus_device *edev = NULL;
+	struct linux_ebus_child *edev_child = NULL;
+	int i = 0;
+
+	/* Traverse through ebus and ebus device list for i2c device and
+	 * adc and gpio nodes.
+	 */
 	for_each_ebus(ebus) {
 		for_each_ebusdev(edev, ebus) {
-			if (!strcmp(edev->prom_name, "SUNW,envctrl"))
-				goto ebus_done;
-			if (!strcmp(edev->prom_name, "SUNW,rasctrl"))
-				goto ebus_done;
+			if (!strcmp(edev->prom_name, "i2c")) {
+				/* In the 2.3.x version we can replace this with just
+				 * an "ioremap()" call, kill envctrl_{readb,writeb}() and
+				 * replace such calls with just a normal {readb,writeb}(). -DaveM
+				 */
+				i2c = (struct pcf8584_reg *) __pa(edev->base_address[0]);
+				for_each_edevchild(edev, edev_child) {
+					if (!strcmp("gpio", edev_child->prom_name)) {
+						i2c_childlist[i].i2ctype = I2C_GPIO;
+						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
+					}
+					if (!strcmp("adc", edev_child->prom_name)) {
+						i2c_childlist[i].i2ctype = I2C_ADC;
+						envctrl_init_i2c_child(edev_child, &(i2c_childlist[i++]));
+					}
+				}
+				goto done;
+			}
 		}
 	}
-ebus_done:
-	if (!edev) {
-		printk("%s: ebus device not found\n", __FUNCTION__);
-		return -ENODEV;
-	}
 
-	if (check_region(edev->base_address[0], sizeof(*i2c))) {
-		printk("%s: Can't get region %lx, %d\n",
-		       __FUNCTION__, edev->base_address[0], (int)sizeof(*i2c));
+done:
+	if (!edev) {
+		printk("envctrl: I2C device not found.\n");
 		return -ENODEV;
 	}
 
-	i2c = (struct pcf8584_reg *)edev->base_address[0];
-
-	request_region((unsigned long)i2c, sizeof(*i2c), "i2c");
-
-	i2c->csr = CONTROL_PIN;
-	i2c->data = PCF8584_ADDRESS;
-	i2c->csr = CONTROL_PIN | CONTROL_ES1;
-	i2c->data = CLK_4_43 | BUS_CLK_90;
-	i2c->csr = CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK;
-	mdelay(10);
+	/* Set device address. */
+	envctrl_writeb(CONTROL_PIN, &i2c->csr);
+	envctrl_writeb(PCF8584_ADDRESS, &i2c->data);
+
+	/* Set system clock and SCL frequencies. */ 
+	envctrl_writeb(CONTROL_PIN | CONTROL_ES1, &i2c->csr);
+	envctrl_writeb(CLK_4_43 | BUS_CLK_90, &i2c->data);
+
+	/* Enable serial interface. */
+	envctrl_writeb(CONTROL_PIN | CONTROL_ES0 | CONTROL_ACK, &i2c->csr);
+	udelay(200);
 
+	/* Register the device as a minor miscellaneous device. */
 	if (misc_register(&envctrl_dev)) {
-		printk("%s: unable to get misc minor %d\n",
-		       __FUNCTION__, envctrl_dev.minor);
-		release_region((unsigned long)i2c, sizeof(*i2c));
+		printk("envctrl: Unable to get misc minor %d\n",
+		       envctrl_dev.minor);
 	}
 
-	err = i2c_scan_bus();
-	if (err)
-		release_region((unsigned long)i2c, sizeof(*i2c));
-	return err;
+	return 0;
 #else
 	return -ENODEV;
 #endif
 }
 
-
 #ifdef MODULE
 void cleanup_module(void)
 {
+	int i;
+
 	misc_deregister(&envctrl_dev);
-	release_region((unsigned long)i2c, sizeof(*i2c));
+
+	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++) {
+		if (i2c_childlist[i].tables)
+			kfree(i2c_childlist[i].tables);
+	}
 }
 #endif