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