GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / atm / nicstarmac.c
1 /*
2  * this file included by nicstar.c
3  */
4
5 /*
6  * nicstarmac.c
7  * Read this ForeRunner's MAC address from eprom/eeprom
8  */
9
10 #include <linux/kernel.h>
11
12 typedef void __iomem *virt_addr_t;
13
14 #define CYCLE_DELAY 5
15
16 /*
17    This was the original definition
18 #define osp_MicroDelay(microsec) \
19     do { int _i = 4*microsec; while (--_i > 0) { __SLOW_DOWN_IO; }} while (0)
20 */
21 #define osp_MicroDelay(microsec) {unsigned long useconds = (microsec); \
22                                   udelay((useconds));}
23 /*
24  * The following tables represent the timing diagrams found in
25  * the Data Sheet for the Xicor X25020 EEProm.  The #defines below
26  * represent the bits in the NICStAR's General Purpose register
27  * that must be toggled for the corresponding actions on the EEProm
28  * to occur.
29  */
30
31 /* Write Data To EEProm from SI line on rising edge of CLK */
32 /* Read Data From EEProm on falling edge of CLK */
33
34 #define CS_HIGH         0x0002  /* Chip select high */
35 #define CS_LOW          0x0000  /* Chip select low (active low) */
36 #define CLK_HIGH        0x0004  /* Clock high */
37 #define CLK_LOW         0x0000  /* Clock low  */
38 #define SI_HIGH         0x0001  /* Serial input data high */
39 #define SI_LOW          0x0000  /* Serial input data low */
40
41 /* Read Status Register = 0000 0101b */
42 #if 0
43 static u_int32_t rdsrtab[] = {
44         CS_HIGH | CLK_HIGH,
45         CS_LOW | CLK_LOW,
46         CLK_HIGH,               /* 0 */
47         CLK_LOW,
48         CLK_HIGH,               /* 0 */
49         CLK_LOW,
50         CLK_HIGH,               /* 0 */
51         CLK_LOW,
52         CLK_HIGH,               /* 0 */
53         CLK_LOW,
54         CLK_HIGH,               /* 0 */
55         CLK_LOW | SI_HIGH,
56         CLK_HIGH | SI_HIGH,     /* 1 */
57         CLK_LOW | SI_LOW,
58         CLK_HIGH,               /* 0 */
59         CLK_LOW | SI_HIGH,
60         CLK_HIGH | SI_HIGH      /* 1 */
61 };
62 #endif /*  0  */
63
64 /* Read from EEPROM = 0000 0011b */
65 static u_int32_t readtab[] = {
66         /*
67            CS_HIGH | CLK_HIGH,
68          */
69         CS_LOW | CLK_LOW,
70         CLK_HIGH,               /* 0 */
71         CLK_LOW,
72         CLK_HIGH,               /* 0 */
73         CLK_LOW,
74         CLK_HIGH,               /* 0 */
75         CLK_LOW,
76         CLK_HIGH,               /* 0 */
77         CLK_LOW,
78         CLK_HIGH,               /* 0 */
79         CLK_LOW,
80         CLK_HIGH,               /* 0 */
81         CLK_LOW | SI_HIGH,
82         CLK_HIGH | SI_HIGH,     /* 1 */
83         CLK_LOW | SI_HIGH,
84         CLK_HIGH | SI_HIGH      /* 1 */
85 };
86
87 /* Clock to read from/write to the eeprom */
88 static u_int32_t clocktab[] = {
89         CLK_LOW,
90         CLK_HIGH,
91         CLK_LOW,
92         CLK_HIGH,
93         CLK_LOW,
94         CLK_HIGH,
95         CLK_LOW,
96         CLK_HIGH,
97         CLK_LOW,
98         CLK_HIGH,
99         CLK_LOW,
100         CLK_HIGH,
101         CLK_LOW,
102         CLK_HIGH,
103         CLK_LOW,
104         CLK_HIGH,
105         CLK_LOW
106 };
107
108 #define NICSTAR_REG_WRITE(bs, reg, val) \
109         while ( readl(bs + STAT) & 0x0200 ) ; \
110         writel((val),(base)+(reg))
111 #define NICSTAR_REG_READ(bs, reg) \
112         readl((base)+(reg))
113 #define NICSTAR_REG_GENERAL_PURPOSE GP
114
115 /*
116  * This routine will clock the Read_Status_reg function into the X2520
117  * eeprom, then pull the result from bit 16 of the NicSTaR's General Purpose 
118  * register.  
119  */
120 #if 0
121 u_int32_t nicstar_read_eprom_status(virt_addr_t base)
122 {
123         u_int32_t val;
124         u_int32_t rbyte;
125         int32_t i, j;
126
127         /* Send read instruction */
128         val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;
129
130         for (i = 0; i < ARRAY_SIZE(rdsrtab); i++) {
131                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
132                                   (val | rdsrtab[i]));
133                 osp_MicroDelay(CYCLE_DELAY);
134         }
135
136         /* Done sending instruction - now pull data off of bit 16, MSB first */
137         /* Data clocked out of eeprom on falling edge of clock */
138
139         rbyte = 0;
140         for (i = 7, j = 0; i >= 0; i--) {
141                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
142                                   (val | clocktab[j++]));
143                 rbyte |= (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE)
144                             & 0x00010000) >> 16) << i);
145                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
146                                   (val | clocktab[j++]));
147                 osp_MicroDelay(CYCLE_DELAY);
148         }
149         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2);
150         osp_MicroDelay(CYCLE_DELAY);
151         return rbyte;
152 }
153 #endif /*  0  */
154
155 /*
156  * This routine will clock the Read_data function into the X2520
157  * eeprom, followed by the address to read from, through the NicSTaR's General
158  * Purpose register.  
159  */
160
161 static u_int8_t read_eprom_byte(virt_addr_t base, u_int8_t offset)
162 {
163         u_int32_t val = 0;
164         int i, j = 0;
165         u_int8_t tempread = 0;
166
167         val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;
168
169         /* Send READ instruction */
170         for (i = 0; i < ARRAY_SIZE(readtab); i++) {
171                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
172                                   (val | readtab[i]));
173                 osp_MicroDelay(CYCLE_DELAY);
174         }
175
176         /* Next, we need to send the byte address to read from */
177         for (i = 7; i >= 0; i--) {
178                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
179                                   (val | clocktab[j++] | ((offset >> i) & 1)));
180                 osp_MicroDelay(CYCLE_DELAY);
181                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
182                                   (val | clocktab[j++] | ((offset >> i) & 1)));
183                 osp_MicroDelay(CYCLE_DELAY);
184         }
185
186         j = 0;
187
188         /* Now, we can read data from the eeprom by clocking it in */
189         for (i = 7; i >= 0; i--) {
190                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
191                                   (val | clocktab[j++]));
192                 osp_MicroDelay(CYCLE_DELAY);
193                 tempread |=
194                     (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE)
195                        & 0x00010000) >> 16) << i);
196                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
197                                   (val | clocktab[j++]));
198                 osp_MicroDelay(CYCLE_DELAY);
199         }
200
201         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2);
202         osp_MicroDelay(CYCLE_DELAY);
203         return tempread;
204 }
205
206 static void nicstar_init_eprom(virt_addr_t base)
207 {
208         u_int32_t val;
209
210         /*
211          * turn chip select off
212          */
213         val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;
214
215         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
216                           (val | CS_HIGH | CLK_HIGH));
217         osp_MicroDelay(CYCLE_DELAY);
218
219         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
220                           (val | CS_HIGH | CLK_LOW));
221         osp_MicroDelay(CYCLE_DELAY);
222
223         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
224                           (val | CS_HIGH | CLK_HIGH));
225         osp_MicroDelay(CYCLE_DELAY);
226
227         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
228                           (val | CS_HIGH | CLK_LOW));
229         osp_MicroDelay(CYCLE_DELAY);
230 }
231
232 /*
233  * This routine will be the interface to the ReadPromByte function
234  * above.
235  */
236
237 static void
238 nicstar_read_eprom(virt_addr_t base,
239                    u_int8_t prom_offset, u_int8_t * buffer, u_int32_t nbytes)
240 {
241         u_int i;
242
243         for (i = 0; i < nbytes; i++) {
244                 buffer[i] = read_eprom_byte(base, prom_offset);
245                 ++prom_offset;
246                 osp_MicroDelay(CYCLE_DELAY);
247         }
248 }