Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* credit winbond-840.c
2 */
3#include <asm/io.h>
4struct 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
14struct eeprom {
15 void *dev;
16 struct eeprom_ops *ops;
17
18 void __iomem * 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
34u8 eeprom_readb(struct eeprom *ee, unsigned address);
35void eeprom_read(struct eeprom *ee, unsigned address, u8 *bytes,
36 unsigned count);
37void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data);
38void eeprom_write(struct eeprom *ee, unsigned address, u8 *bytes,
39 unsigned count);
40
41/* The EEPROM commands include the alway-set leading bit. */
42enum EEPROM_Cmds {
43 EE_WriteCmd=(5 << 6), EE_ReadCmd=(6 << 6), EE_EraseCmd=(7 << 6),
44};
45
46void setup_ee_mem_bitbanger(struct eeprom *ee, void __iomem *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 */
60static 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
78void 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
86void 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
94void 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
110u16 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
134void eeprom_writeb(struct eeprom *ee, unsigned address, u8 data)
135{
136}