[net-next-2.6.git] / arch / mips / sgi-ip22 / ip22-nvram.c

/*
 * ip22-nvram.c: NVRAM and serial EEPROM handling.
 *
 * Copyright (C) 2003 Ladislav Michl (ladis@linux-mips.org)
 */
#include <linux/module.h>

#include <asm/sgi/hpc3.h>
#include <asm/sgi/ip22.h>

/* Control opcode for serial eeprom  */
#define EEPROM_READ	0xc000	/* serial memory read */
#define EEPROM_WEN	0x9800	/* write enable before prog modes */
#define EEPROM_WRITE	0xa000	/* serial memory write */
#define EEPROM_WRALL	0x8800	/* write all registers */
#define EEPROM_WDS	0x8000	/* disable all programming */
#define	EEPROM_PRREAD	0xc000	/* read protect register */
#define	EEPROM_PREN	0x9800	/* enable protect register mode */
#define	EEPROM_PRCLEAR	0xffff	/* clear protect register */
#define	EEPROM_PRWRITE	0xa000	/* write protect register */
#define	EEPROM_PRDS	0x8000	/* disable protect register, forever */

#define EEPROM_EPROT	0x01	/* Protect register enable */
#define EEPROM_CSEL	0x02	/* Chip select */
#define EEPROM_ECLK	0x04	/* EEPROM clock */
#define EEPROM_DATO	0x08	/* Data out */
#define EEPROM_DATI	0x10	/* Data in */

/* We need to use these functions early... */
#define delay()	({						\
	int x;							\
	for (x=0; x<100000; x++) __asm__ __volatile__(""); })

#define eeprom_cs_on(ptr) ({	\
	*ptr &= ~EEPROM_DATO;	\
	*ptr &= ~EEPROM_ECLK;	\
	*ptr &= ~EEPROM_EPROT;	\
	delay();		\
	*ptr |= EEPROM_CSEL;	\
	*ptr |= EEPROM_ECLK; })

		
#define eeprom_cs_off(ptr) ({	\
	*ptr &= ~EEPROM_ECLK;	\
	*ptr &= ~EEPROM_CSEL;	\
	*ptr |= EEPROM_EPROT;	\
	*ptr |= EEPROM_ECLK; })

#define	BITS_IN_COMMAND	11
/*
 * clock in the nvram command and the register number. For the
 * national semiconductor nv ram chip the op code is 3 bits and
 * the address is 6/8 bits. 
 */
static inline void eeprom_cmd(volatile unsigned int *ctrl, unsigned cmd,
			      unsigned reg)
{
	unsigned short ser_cmd;
	int i;

	ser_cmd = cmd | (reg << (16 - BITS_IN_COMMAND));
	for (i = 0; i < BITS_IN_COMMAND; i++) {
		if (ser_cmd & (1<<15))	/* if high order bit set */
			*ctrl |= EEPROM_DATO;
		else
			*ctrl &= ~EEPROM_DATO;
		*ctrl &= ~EEPROM_ECLK;
		*ctrl |= EEPROM_ECLK;
		ser_cmd <<= 1;
	}
	*ctrl &= ~EEPROM_DATO;	/* see data sheet timing diagram */
}

unsigned short ip22_eeprom_read(volatile unsigned int *ctrl, int reg)
{
	unsigned short res = 0;
	int i;

	*ctrl &= ~EEPROM_EPROT;
	eeprom_cs_on(ctrl);
	eeprom_cmd(ctrl, EEPROM_READ, reg);

	/* clock the data ouf of serial mem */
	for (i = 0; i < 16; i++) {
		*ctrl &= ~EEPROM_ECLK;
		delay();
		*ctrl |= EEPROM_ECLK;
		delay();
		res <<= 1;
		if (*ctrl & EEPROM_DATI)
			res |= 1;
	}
		
	eeprom_cs_off(ctrl);

	return res;
}

EXPORT_SYMBOL(ip22_eeprom_read);

/*
 * Read specified register from main NVRAM
 */
unsigned short ip22_nvram_read(int reg)
{
	if (ip22_is_fullhouse())
		/* IP22 (Indigo2 aka FullHouse) stores env variables into
		 * 93CS56 Microwire Bus EEPROM 2048 Bit (128x16) */
		return ip22_eeprom_read(&hpc3c0->eeprom, reg);
	else {
		unsigned short tmp;
		/* IP24 (Indy aka Guiness) uses DS1386 8K version */
		reg <<= 1;
		tmp = hpc3c0->bbram[reg++] & 0xff;
		return (tmp << 8) | (hpc3c0->bbram[reg] & 0xff);
	}		
}

EXPORT_SYMBOL(ip22_nvram_read);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* ip22-nvram.c: NVRAM and serial EEPROM handling.
	3	*
	4	* Copyright (C) 2003 Ladislav Michl (ladis@linux-mips.org)
	5	*/
	6	#include <linux/module.h>
	7
	8	#include <asm/sgi/hpc3.h>
	9	#include <asm/sgi/ip22.h>
	10
	11	/* Control opcode for serial eeprom */
	12	#define EEPROM_READ 0xc000 /* serial memory read */
	13	#define EEPROM_WEN 0x9800 /* write enable before prog modes */
	14	#define EEPROM_WRITE 0xa000 /* serial memory write */
	15	#define EEPROM_WRALL 0x8800 /* write all registers */
	16	#define EEPROM_WDS 0x8000 /* disable all programming */
	17	#define EEPROM_PRREAD 0xc000 /* read protect register */
	18	#define EEPROM_PREN 0x9800 /* enable protect register mode */
	19	#define EEPROM_PRCLEAR 0xffff /* clear protect register */
	20	#define EEPROM_PRWRITE 0xa000 /* write protect register */
	21	#define EEPROM_PRDS 0x8000 /* disable protect register, forever */
	22
	23	#define EEPROM_EPROT 0x01 /* Protect register enable */
	24	#define EEPROM_CSEL 0x02 /* Chip select */
	25	#define EEPROM_ECLK 0x04 /* EEPROM clock */
	26	#define EEPROM_DATO 0x08 /* Data out */
	27	#define EEPROM_DATI 0x10 /* Data in */
	28
	29	/* We need to use these functions early... */
	30	#define delay() ({ \
	31	int x; \
	32	for (x=0; x<100000; x++) __asm__ __volatile__(""); })
	33
	34	#define eeprom_cs_on(ptr) ({ \
	35	*ptr &= ~EEPROM_DATO; \
	36	*ptr &= ~EEPROM_ECLK; \
	37	*ptr &= ~EEPROM_EPROT; \
	38	delay(); \
	39	*ptr \|= EEPROM_CSEL; \
	40	*ptr \|= EEPROM_ECLK; })
	41
	42
	43	#define eeprom_cs_off(ptr) ({ \
	44	*ptr &= ~EEPROM_ECLK; \
	45	*ptr &= ~EEPROM_CSEL; \
	46	*ptr \|= EEPROM_EPROT; \
	47	*ptr \|= EEPROM_ECLK; })
	48
	49	#define BITS_IN_COMMAND 11
	50	/*
	51	* clock in the nvram command and the register number. For the
	52	* national semiconductor nv ram chip the op code is 3 bits and
	53	* the address is 6/8 bits.
	54	*/
	55	static inline void eeprom_cmd(volatile unsigned int *ctrl, unsigned cmd,
	56	unsigned reg)
	57	{
	58	unsigned short ser_cmd;
	59	int i;
	60
	61	ser_cmd = cmd \| (reg << (16 - BITS_IN_COMMAND));
	62	for (i = 0; i < BITS_IN_COMMAND; i++) {
	63	if (ser_cmd & (1<<15)) /* if high order bit set */
	64	*ctrl \|= EEPROM_DATO;
65	else
66	*ctrl &= ~EEPROM_DATO;
67	*ctrl &= ~EEPROM_ECLK;
68	*ctrl \|= EEPROM_ECLK;
69	ser_cmd <<= 1;
70	}
71	ctrl &= ~EEPROM_DATO; / see data sheet timing diagram */
72	}
73
74	unsigned short ip22_eeprom_read(volatile unsigned int *ctrl, int reg)
75	{
76	unsigned short res = 0;
77	int i;
78
79	*ctrl &= ~EEPROM_EPROT;
80	eeprom_cs_on(ctrl);
81	eeprom_cmd(ctrl, EEPROM_READ, reg);
82
83	/* clock the data ouf of serial mem */
84	for (i = 0; i < 16; i++) {
85	*ctrl &= ~EEPROM_ECLK;
86	delay();
87	*ctrl \|= EEPROM_ECLK;
88	delay();
89	res <<= 1;
90	if (*ctrl & EEPROM_DATI)
91	res \|= 1;
92	}
93
94	eeprom_cs_off(ctrl);
95
96	return res;
97	}
98
99	EXPORT_SYMBOL(ip22_eeprom_read);
100
101	/*
102	* Read specified register from main NVRAM
103	*/
104	unsigned short ip22_nvram_read(int reg)
105	{
106	if (ip22_is_fullhouse())
107	/* IP22 (Indigo2 aka FullHouse) stores env variables into
108	* 93CS56 Microwire Bus EEPROM 2048 Bit (128x16) */
109	return ip22_eeprom_read(&hpc3c0->eeprom, reg);
110	else {
111	unsigned short tmp;
112	/* IP24 (Indy aka Guiness) uses DS1386 8K version */
113	reg <<= 1;
114	tmp = hpc3c0->bbram[reg++] & 0xff;
115	return (tmp << 8) \| (hpc3c0->bbram[reg] & 0xff);
116	}
117	}
118
119	EXPORT_SYMBOL(ip22_nvram_read);