envctrl.c

讲述linux的初始化过程

		 * 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_read(struct file *file, char *buf, size_t count, loff_t *ppos)
{
	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_GLOBALADDRESS:
		if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_MON)))
			return 0;
		data[0] = envctrl_i2c_read_8574(pchild->addr);
		ret = envctrl_i2c_globaladdr(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)))
			/* If voltage monitor not present, check for CPCI equivalent */
			if (!(pchild = envctrl_get_i2c_child(ENVCTRL_GLOBALADDR_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 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)
{
	char *infobuf;

	switch (cmd) {
	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:
	case ENVCTRL_RD_GLOBALADDRESS:
		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)
{
	file->private_data = 0;
	MOD_INC_USE_COUNT;
	return 0;
}

/* Function Description: Open device. Mapped to user close().
 * Return: Always 0.
 */
static int
envctrl_release(struct inode *inode, struct file *file)
{
	MOD_DEC_USE_COUNT;
	return 0;
}

static struct file_operations envctrl_fops = {
	owner:		THIS_MODULE,
	read:		envctrl_read,
	ioctl:		envctrl_ioctl,
	open:		envctrl_open,
	release:	envctrl_release,
};	

static struct miscdevice envctrl_dev = {
	ENVCTRL_MINOR,
	"envctrl",
	&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;
}

/* 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;
}

/* Function Description: Initialize child device for global addressing line.
 * Return: None.
 */
static void envctrl_init_globaladdr(struct i2c_child_t *pchild)
{
	int i;

	/* Voltage/PowerSupply monitoring is piggybacked 
	 * with Global Address on CompactPCI.  See comments
	 * within envctrl_i2c_globaladdr for bit assignments.
	 *
	 * The mask is created here by assigning mask bits to each
	 * bit position that represents PCF8584_VOLTAGE_TYPE data.
	 * Channel numbers are not consecutive within the globaladdr
	 * node (why?), so we use the actual counter value as chnls_mask
	 * index instead of the chnl_array[x].chnl_no value.
	 *
	 * NOTE: This loop could be replaced with a constant representing
	 * a mask of bits 5&6 (ENVCTRL_GLOBALADDR_PSTAT_MASK).
	 */
	for (i = 0; i < pchild->total_chnls; i++) {
		if (PCF8584_VOLTAGE_TYPE == pchild->chnl_array[i].type) {
			pchild->voltage_mask |= chnls_mask[i];
		}
	}

	/* We only need to know if this child has global addressing 
	 * line monitored.  We dont care which channels since we know 
	 * the mask already (ENVCTRL_GLOBALADDR_ADDR_MASK).
	 */
	pchild->mon_type[0] = ENVCTRL_GLOBALADDR_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;
		}
	}

	/* SPARCengine ASM Reference Manual (ref. SMI doc 805-7581-04)
	 * sections 2.5, 3.5, 4.5 state node 0x70 for CP1400/1500 is
	 * "For Factory Use Only."
	 *
	 * We ignore the node on these platforms by assigning the
	 * 'NULL' monitor type.
	 */
	if (ENVCTRL_CPCI_IGNORED_NODE == pchild->addr) {
		int len;
		char prop[56];

		len = prom_getproperty(prom_root_node, "name", prop, sizeof(prop));
		if (0 < len && (0 == strncmp(prop, "SUNW,UltraSPARC-IIi-cEngine", len)))
		{
			for (len = 0; len < PCF8584_MAX_CHANNELS; ++len) {
				pchild->mon_type[len] = ENVCTRL_NOMON;
			}
			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_GLOBALADDR_TYPE:
			envctrl_init_globaladdr(pchild);
			i = pchild->total_chnls;
			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;
}

static int __init envctrl_init(void)
{
#ifdef CONFIG_PCI
	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, "i2c")) {
				i2c = ioremap(	edev->resource[0].start, 
								sizeof(struct pcf8584_reg));
				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;
			}
		}
	}

done:
	if (!edev) {
		printk("envctrl: I2C device not found.\n");
		return -ENODEV;
	}

	/* 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("envctrl: Unable to get misc minor %d\n",
		       envctrl_dev.minor);
	}

	/* Note above traversal routine post-incremented 'i' to accomodate 
	 * a next child device, so we decrement before reverse-traversal of
	 * child devices.
	 */
	printk("envctrl: initialized ");
	for (--i; i >= 0; --i) {
		printk("[%s 0x%lx]%s", 
			(I2C_ADC == i2c_childlist[i].i2ctype) ? ("adc") : 
			((I2C_GPIO == i2c_childlist[i].i2ctype) ? ("gpio") : ("unknown")), 
			i2c_childlist[i].addr, (0 == i) ? ("\n") : (" "));
	}

	return 0;
#else
	return -ENODEV;
#endif
}

static void __exit envctrl_cleanup(void)
{
	int i;

	iounmap(i2c);
	misc_deregister(&envctrl_dev);

	for (i = 0; i < ENVCTRL_MAX_CPU * 2; i++) {
		if (i2c_childlist[i].tables)
			kfree(i2c_childlist[i].tables);
	}
}

module_init(envctrl_init);
module_exit(envctrl_cleanup);