include/linux/eeprom.h

   1 /* credit winbond-840.c
   2  */
   3 #include <asm/io.h>
   4 struct eeprom_ops {
   5         void    (*set_cs)(void *ee);
   6         void    (*clear_cs)(void *ee);
   7 };
   8
   9 #define EEPOL_EEDI      0x01
  10 #define EEPOL_EEDO      0x02
  11 #define EEPOL_EECLK     0x04
  12 #define EEPOL_EESEL     0x08
  13
  14 struct eeprom {
  15         void *dev;
  16         struct eeprom_ops *ops;
  17
  18         long            addr;
  19
  20         unsigned        ee_addr_bits;
  21
  22         unsigned        eesel;
  23         unsigned        eeclk;
  24         unsigned        eedo;
  25         unsigned        eedi;
  26         unsigned        polarity;
  27         unsigned        ee_state;
  28
  29         spinlock_t      *lock;
  30         u32             *cache;
  31 };
  32
  33
  34 u8   eeprom_readb(struct eeprom *ee, unsigned address);
  35 void eeprom_read(struct eeprom *ee, unsigned address, u8 *bytes,
  36                 unsigned count);
  37 void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data);
  38 void eeprom_write(struct eeprom *ee, unsigned address, u8 *bytes,
  39                 unsigned count);
  40
  41 /* The EEPROM commands include the alway-set leading bit. */
  42 enum EEPROM_Cmds {
  43         EE_WriteCmd=(5 << 6), EE_ReadCmd=(6 << 6), EE_EraseCmd=(7 << 6),
  44 };
  45
  46 void setup_ee_mem_bitbanger(struct eeprom *ee, long memaddr, int eesel_bit, int eeclk_bit, int eedo_bit, int eedi_bit, unsigned polarity)
  47 {
  48         ee->addr = memaddr;
  49         ee->eesel = 1 << eesel_bit;
  50         ee->eeclk = 1 << eeclk_bit;
  51         ee->eedo = 1 << eedo_bit;
  52         ee->eedi = 1 << eedi_bit;
  53
  54         ee->polarity = polarity;
  55
  56         *ee->cache = readl(ee->addr);
  57 }
  58
  59 /* foo. put this in a .c file */
  60 static inline void eeprom_update(struct eeprom *ee, u32 mask, int pol)
  61 {
  62         unsigned long flags;
  63         u32 data;
  64
  65         spin_lock_irqsave(ee->lock, flags);
  66         data = *ee->cache;
  67
  68         data &= ~mask;
  69         if (pol)
  70                 data |= mask;
  71
  72         *ee->cache = data;
  73 //printk("update: %08x\n", data);
  74         writel(data, ee->addr);
  75         spin_unlock_irqrestore(ee->lock, flags);
  76 }
  77
  78 void eeprom_clk_lo(struct eeprom *ee)
  79 {
  80         int pol = !!(ee->polarity & EEPOL_EECLK);
  81
  82         eeprom_update(ee, ee->eeclk, pol);
  83         udelay(2);
  84 }
  85
  86 void eeprom_clk_hi(struct eeprom *ee)
  87 {
  88         int pol = !!(ee->polarity & EEPOL_EECLK);
  89
  90         eeprom_update(ee, ee->eeclk, !pol);
  91         udelay(2);
  92 }
  93
  94 void eeprom_send_addr(struct eeprom *ee, unsigned address)
  95 {
  96         int pol = !!(ee->polarity & EEPOL_EEDI);
  97         unsigned i;
  98         address |= 6 << 6;
  99
 100         /* Shift the read command bits out. */
 101         for (i=0; i<11; i++) {
 102                 eeprom_update(ee, ee->eedi, ((address >> 10) & 1) ^ pol);
 103                 address <<= 1;
 104                 eeprom_clk_hi(ee);
 105                 eeprom_clk_lo(ee);
 106         }
 107         eeprom_update(ee, ee->eedi, pol);
 108 }
 109
 110 u16   eeprom_readw(struct eeprom *ee, unsigned address)
 111 {
 112         unsigned i;
 113         u16     res = 0;
 114
 115         eeprom_clk_lo(ee);
 116         eeprom_update(ee, ee->eesel, 1 ^ !!(ee->polarity & EEPOL_EESEL));
 117         eeprom_send_addr(ee, address);
 118
 119         for (i=0; i<16; i++) {
 120                 u32 data;
 121                 eeprom_clk_hi(ee);
 122                 res <<= 1;
 123                 data = readl(ee->addr);
 124 //printk("eeprom_readw: %08x\n", data);
 125                 res |= !!(data & ee->eedo) ^ !!(ee->polarity & EEPOL_EEDO);
 126                 eeprom_clk_lo(ee);
 127         }
 128         eeprom_update(ee, ee->eesel, 0 ^ !!(ee->polarity & EEPOL_EESEL));
 129
 130         return res;
 131 }
 132
 133
 134 void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data)
 135 {
 136 }