Viewing file:  eeprom.h (2.77 KB) -rw-r--r--
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/* credit winbond-840.c
*/
#include <asm/io.h>
struct eeprom_ops {
void (*set_cs)(void *ee);
void (*clear_cs)(void *ee);
};
#define EEPOL_EEDI 0x01
#define EEPOL_EEDO 0x02
#define EEPOL_EECLK 0x04
#define EEPOL_EESEL 0x08
struct eeprom {
void *dev;
struct eeprom_ops *ops;
long addr;
unsigned ee_addr_bits;
unsigned eesel;
unsigned eeclk;
unsigned eedo;
unsigned eedi;
unsigned polarity;
unsigned ee_state;
spinlock_t *lock;
u32 *cache;
};
u8 eeprom_readb(struct eeprom *ee, unsigned address);
void eeprom_read(struct eeprom *ee, unsigned address, u8 *bytes,
unsigned count);
void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data);
void eeprom_write(struct eeprom *ee, unsigned address, u8 *bytes,
unsigned count);
/* The EEPROM commands include the alway-set leading bit. */
enum EEPROM_Cmds {
EE_WriteCmd=(5 << 6), EE_ReadCmd=(6 << 6), EE_EraseCmd=(7 << 6),
};
void setup_ee_mem_bitbanger(struct eeprom *ee, long memaddr, int eesel_bit, int eeclk_bit, int eedo_bit, int eedi_bit, unsigned polarity)
{
ee->addr = memaddr;
ee->eesel = 1 << eesel_bit;
ee->eeclk = 1 << eeclk_bit;
ee->eedo = 1 << eedo_bit;
ee->eedi = 1 << eedi_bit;
ee->polarity = polarity;
*ee->cache = readl(ee->addr);
}
/* foo. put this in a .c file */
static inline void eeprom_update(struct eeprom *ee, u32 mask, int pol)
{
long flags;
u32 data;
spin_lock_irqsave(ee->lock, flags);
data = *ee->cache;
data &= ~mask;
if (pol)
data |= mask;
*ee->cache = data;
//printk("update: %08x\n", data);
writel(data, ee->addr);
spin_unlock_irqrestore(ee->lock, flags);
}
void eeprom_clk_lo(struct eeprom *ee)
{
int pol = !!(ee->polarity & EEPOL_EECLK);
eeprom_update(ee, ee->eeclk, pol);
udelay(2);
}
void eeprom_clk_hi(struct eeprom *ee)
{
int pol = !!(ee->polarity & EEPOL_EECLK);
eeprom_update(ee, ee->eeclk, !pol);
udelay(2);
}
void eeprom_send_addr(struct eeprom *ee, unsigned address)
{
int pol = !!(ee->polarity & EEPOL_EEDI);
unsigned i;
address |= 6 << 6;
/* Shift the read command bits out. */
for (i=0; i<11; i++) {
eeprom_update(ee, ee->eedi, ((address >> 10) & 1) ^ pol);
address <<= 1;
eeprom_clk_hi(ee);
eeprom_clk_lo(ee);
}
eeprom_update(ee, ee->eedi, pol);
}
u16 eeprom_readw(struct eeprom *ee, unsigned address)
{
unsigned i;
u16 res = 0;
eeprom_clk_lo(ee);
eeprom_update(ee, ee->eesel, 1 ^ !!(ee->polarity & EEPOL_EESEL));
eeprom_send_addr(ee, address);
for (i=0; i<16; i++) {
u32 data;
eeprom_clk_hi(ee);
res <<= 1;
data = readl(ee->addr);
//printk("eeprom_readw: %08x\n", data);
res |= !!(data & ee->eedo) ^ !!(ee->polarity & EEPOL_EEDO);
eeprom_clk_lo(ee);
}
eeprom_update(ee, ee->eesel, 0 ^ !!(ee->polarity & EEPOL_EESEL));
return res;
}
void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data)
{
}
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