envctrl.c

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/* $Id: envctrl.c,v 1.19 2000/11/03 00:37:40 davem Exp $
 * envctrl.c: Temperature and Fan monitoring on Machines providing it.
 *
 * Copyright (C) 1998  Eddie C. Dost  ([e-mail])
 * Copyright (C) 2000  Vinh Truong    ([e-mail])
 * 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
 *
 * EB - Added support for CP1500 Global Address and PS/Voltage monitoring.
 * 		Eric Brower <[e-mail]>
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/delay.h>
#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>
#include <asm/envctrl.h>

#define ENVCTRL_MINOR	162

#define PCF8584_ADDRESS	0x55

#define CONTROL_PIN	0x80
#define CONTROL_ES0	0x40
#define CONTROL_ES1	0x20
#define CONTROL_ES2	0x10
#define CONTROL_ENI	0x08
#define CONTROL_STA	0x04
#define CONTROL_STO	0x02
#define CONTROL_ACK	0x01

#define STATUS_PIN	0x80
#define STATUS_STS	0x20
#define STATUS_BER	0x10
#define STATUS_LRB	0x08
#define STATUS_AD0	0x08
#define STATUS_AAB	0x04
#define STATUS_LAB	0x02
#define STATUS_BB	0x01

/*
 * CLK Mode Register.
 */
#define BUS_CLK_90	0x00
#define BUS_CLK_45	0x01
#define BUS_CLK_11	0x02
#define BUS_CLK_1_5	0x03

#define CLK_3		0x00
#define CLK_4_43	0x10
#define CLK_6		0x14
#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 */

/* Monitor type of i2c child device.
 * Firmware definitions.
 */
#define PCF8584_MAX_CHANNELS            8
#define PCF8584_GLOBALADDR_TYPE			6  /* global address monitor */
#define PCF8584_FANSTAT_TYPE            3  /* fan status monitor */
#define PCF8584_VOLTAGE_TYPE            2  /* voltage monitor    */
#define PCF8584_TEMP_TYPE	        	1  /* temperature monitor*/

/* 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 */
#define ENVCTRL_GLOBALADDR_MON		8    /* global address */

/* 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

/* Mask values for combined GlobalAddress/PowerStatus node */
#define ENVCTRL_GLOBALADDR_ADDR_MASK 	0x1F
#define ENVCTRL_GLOBALADDR_PSTAT_MASK	0x60

/* Node 0x70 ignored on CompactPCI CP1400/1500 platforms 
 * (see envctrl_init_i2c_child)
 */
#define ENVCTRL_CPCI_IGNORED_NODE		0x70

struct pcf8584_reg {
	 unsigned char data;
	 unsigned char csr;
};

/* 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;
};

/* 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;
};

/* 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];
};

volatile 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(volatile unsigned char *p)
{
	return readb(p);
}

/* Function description: Write a byte to an i2c controller register.
 * Return: Nothing.
 */
static inline void envctrl_writeb(unsigned char val, volatile unsigned char *p)
{
	writeb(val, p);
}

/* 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)
{
	int limit = 1000000;

	while (--limit > 0) {
		if (!(envctrl_readb(&i2c->csr) & STATUS_PIN)) 
			break;
		udelay(1);
	} 

	if (limit <= 0)
		printk(KERN_INFO "envctrl: Pin status will not clear.\n");
}

/* 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);
	} 

	if (limit <= 0)
		printk(KERN_INFO "envctrl: Busy bit will not clear.\n");
}

/* 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();

	/* Load address. */
	envctrl_writeb(addr + 1, &i2c->data);

	envctrl_i2c_test_bb();

	envctrl_writeb(OBD_SEND_START, &i2c->csr);

	/* Wait for PIN. */
	envtrl_i2c_test_pin();

	/* 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;
	}
}

/* Function Description: Send the adress for write mode.  
 * Return : None.
 */
static void envctrl_i2c_write_addr(unsigned char addr)
{
	envctrl_i2c_test_bb();
	envctrl_writeb(addr, &i2c->data);

	/* Generate Start condition. */
	envctrl_writeb(OBD_SEND_START, &i2c->csr);
}

/* 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);
}

/* 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);
}

/* 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);
}

/* 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);

	/* Setup port to read. */
	envctrl_i2c_write_data(port);
	envctrl_i2c_stop();

	/* Read port. */
	envctrl_i2c_read_addr(addr);

	/* Do a single byte read and send stop. */
	envctrl_i2c_read_data();
	envctrl_i2c_stop();

	return envctrl_readb(&i2c->data);
}

/* Function Description: Read gpio device.
 * Return : Data at address.
 */
static unsigned char envctrl_i2c_read_8574(unsigned char addr)
{
	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 (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);
}

/* 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)
{
	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);
}

/* 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++;
			}
		}
	}

	bufdata[0] = ret;
	return 1;
}

/* Function Description: Read global addressing line.
 * Return : Always 1 byte. Status stored in bufdata.
 */
static int envctrl_i2c_globaladdr(struct i2c_child_t *pchild,
				  unsigned char data,
				  char *bufdata)
{
	/* Translatation table is not necessary, as global
	 * addr is the integer value of the GA# bits.
	 *
	 * NOTE: MSB is documented as zero, but I see it as '1' always....
	 *
	 * -----------------------------------------------
	 * | 0 | FAL | DEG | GA4 | GA3 | GA2 | GA1 | GA0 |
	 * -----------------------------------------------
	 * GA0 - GA4	integer value of Global Address (backplane slot#)
	 * DEG			0 = cPCI Power supply output is starting to degrade
	 * 				1 = cPCI Power supply output is OK
	 * FAL			0 = cPCI Power supply has failed
	 * 				1 = cPCI Power supply output is OK
	 */
	bufdata[0] = (data & ENVCTRL_GLOBALADDR_ADDR_MASK);
	return 1;
}

/* Function Description: Read standard 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