drivers/atm/nicstarmac.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * this file included by nicstar.c
   4  */
   5
   6 /*
   7  * nicstarmac.c
   8  * Read this ForeRunner's MAC address from eprom/eeprom
   9  */
  10
  11 #include <linux/kernel.h>
  12
  13 typedef void __iomem *virt_addr_t;
  14
  15 #define CYCLE_DELAY 5
  16
  17 /*
  18    This was the original definition
  19 #define osp_MicroDelay(microsec) \
  20     do { int _i = 4*microsec; while (--_i > 0) { __SLOW_DOWN_IO; }} while (0)
  21 */
  22 #define osp_MicroDelay(microsec) {unsigned long useconds = (microsec); \
  23                                   udelay((useconds));}
  24 /*
  25  * The following tables represent the timing diagrams found in
  26  * the Data Sheet for the Xicor X25020 EEProm.  The #defines below
  27  * represent the bits in the NICStAR's General Purpose register
  28  * that must be toggled for the corresponding actions on the EEProm
  29  * to occur.
  30  */
  31
  32 /* Write Data To EEProm from SI line on rising edge of CLK */
  33 /* Read Data From EEProm on falling edge of CLK */
  34
  35 #define CS_HIGH         0x0002  /* Chip select high */
  36 #define CS_LOW          0x0000  /* Chip select low (active low) */
  37 #define CLK_HIGH        0x0004  /* Clock high */
  38 #define CLK_LOW         0x0000  /* Clock low  */
  39 #define SI_HIGH         0x0001  /* Serial input data high */
  40 #define SI_LOW          0x0000  /* Serial input data low */
  41
  42 /* Read Status Register = 0000 0101b */
  43 #if 0
  44 static u_int32_t rdsrtab[] = {
  45         CS_HIGH | CLK_HIGH,
  46         CS_LOW | CLK_LOW,
  47         CLK_HIGH,               /* 0 */
  48         CLK_LOW,
  49         CLK_HIGH,               /* 0 */
  50         CLK_LOW,
  51         CLK_HIGH,               /* 0 */
  52         CLK_LOW,
  53         CLK_HIGH,               /* 0 */
  54         CLK_LOW,
  55         CLK_HIGH,               /* 0 */
  56         CLK_LOW | SI_HIGH,
  57         CLK_HIGH | SI_HIGH,     /* 1 */
  58         CLK_LOW | SI_LOW,
  59         CLK_HIGH,               /* 0 */
  60         CLK_LOW | SI_HIGH,
  61         CLK_HIGH | SI_HIGH      /* 1 */
  62 };
  63 #endif /*  0  */
  64
  65 /* Read from EEPROM = 0000 0011b */
  66 static u_int32_t readtab[] = {
  67         /*
  68            CS_HIGH | CLK_HIGH,
  69          */
  70         CS_LOW | CLK_LOW,
  71         CLK_HIGH,               /* 0 */
  72         CLK_LOW,
  73         CLK_HIGH,               /* 0 */
  74         CLK_LOW,
  75         CLK_HIGH,               /* 0 */
  76         CLK_LOW,
  77         CLK_HIGH,               /* 0 */
  78         CLK_LOW,
  79         CLK_HIGH,               /* 0 */
  80         CLK_LOW,
  81         CLK_HIGH,               /* 0 */
  82         CLK_LOW | SI_HIGH,
  83         CLK_HIGH | SI_HIGH,     /* 1 */
  84         CLK_LOW | SI_HIGH,
  85         CLK_HIGH | SI_HIGH      /* 1 */
  86 };
  87
  88 /* Clock to read from/write to the eeprom */
  89 static u_int32_t clocktab[] = {
  90         CLK_LOW,
  91         CLK_HIGH,
  92         CLK_LOW,
  93         CLK_HIGH,
  94         CLK_LOW,
  95         CLK_HIGH,
  96         CLK_LOW,
  97         CLK_HIGH,
  98         CLK_LOW,
  99         CLK_HIGH,
 100         CLK_LOW,
 101         CLK_HIGH,
 102         CLK_LOW,
 103         CLK_HIGH,
 104         CLK_LOW,
 105         CLK_HIGH,
 106         CLK_LOW
 107 };
 108
 109 #define NICSTAR_REG_WRITE(bs, reg, val) \
 110         while ( readl(bs + STAT) & 0x0200 ) ; \
 111         writel((val),(base)+(reg))
 112 #define NICSTAR_REG_READ(bs, reg) \
 113         readl((base)+(reg))
 114 #define NICSTAR_REG_GENERAL_PURPOSE GP
 115
 116 /*
 117  * This routine will clock the Read_Status_reg function into the X2520
 118  * eeprom, then pull the result from bit 16 of the NicSTaR's General Purpose
 119  * register.
 120  */
 121 #if 0
 122 u_int32_t nicstar_read_eprom_status(virt_addr_t base)
 123 {
 124         u_int32_t val;
 125         u_int32_t rbyte;
 126         int32_t i, j;
 127
 128         /* Send read instruction */
 129         val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;
 130
 131         for (i = 0; i < ARRAY_SIZE(rdsrtab); i++) {
 132                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 133                                   (val | rdsrtab[i]));
 134                 osp_MicroDelay(CYCLE_DELAY);
 135         }
 136
 137         /* Done sending instruction - now pull data off of bit 16, MSB first */
 138         /* Data clocked out of eeprom on falling edge of clock */
 139
 140         rbyte = 0;
 141         for (i = 7, j = 0; i >= 0; i--) {
 142                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 143                                   (val | clocktab[j++]));
 144                 rbyte |= (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE)
 145                             & 0x00010000) >> 16) << i);
 146                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 147                                   (val | clocktab[j++]));
 148                 osp_MicroDelay(CYCLE_DELAY);
 149         }
 150         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2);
 151         osp_MicroDelay(CYCLE_DELAY);
 152         return rbyte;
 153 }
 154 #endif /*  0  */
 155
 156 /*
 157  * This routine will clock the Read_data function into the X2520
 158  * eeprom, followed by the address to read from, through the NicSTaR's General
 159  * Purpose register.
 160  */
 161
 162 static u_int8_t read_eprom_byte(virt_addr_t base, u_int8_t offset)
 163 {
 164         u_int32_t val = 0;
 165         int i, j = 0;
 166         u_int8_t tempread = 0;
 167
 168         val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;
 169
 170         /* Send READ instruction */
 171         for (i = 0; i < ARRAY_SIZE(readtab); i++) {
 172                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 173                                   (val | readtab[i]));
 174                 osp_MicroDelay(CYCLE_DELAY);
 175         }
 176
 177         /* Next, we need to send the byte address to read from */
 178         for (i = 7; i >= 0; i--) {
 179                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 180                                   (val | clocktab[j++] | ((offset >> i) & 1)));
 181                 osp_MicroDelay(CYCLE_DELAY);
 182                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 183                                   (val | clocktab[j++] | ((offset >> i) & 1)));
 184                 osp_MicroDelay(CYCLE_DELAY);
 185         }
 186
 187         j = 0;
 188
 189         /* Now, we can read data from the eeprom by clocking it in */
 190         for (i = 7; i >= 0; i--) {
 191                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 192                                   (val | clocktab[j++]));
 193                 osp_MicroDelay(CYCLE_DELAY);
 194                 tempread |=
 195                     (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE)
 196                        & 0x00010000) >> 16) << i);
 197                 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 198                                   (val | clocktab[j++]));
 199                 osp_MicroDelay(CYCLE_DELAY);
 200         }
 201
 202         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2);
 203         osp_MicroDelay(CYCLE_DELAY);
 204         return tempread;
 205 }
 206
 207 static void nicstar_init_eprom(virt_addr_t base)
 208 {
 209         u_int32_t val;
 210
 211         /*
 212          * turn chip select off
 213          */
 214         val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;
 215
 216         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 217                           (val | CS_HIGH | CLK_HIGH));
 218         osp_MicroDelay(CYCLE_DELAY);
 219
 220         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 221                           (val | CS_HIGH | CLK_LOW));
 222         osp_MicroDelay(CYCLE_DELAY);
 223
 224         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 225                           (val | CS_HIGH | CLK_HIGH));
 226         osp_MicroDelay(CYCLE_DELAY);
 227
 228         NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,
 229                           (val | CS_HIGH | CLK_LOW));
 230         osp_MicroDelay(CYCLE_DELAY);
 231 }
 232
 233 /*
 234  * This routine will be the interface to the ReadPromByte function
 235  * above.
 236  */
 237
 238 static void
 239 nicstar_read_eprom(virt_addr_t base,
 240                    u_int8_t prom_offset, u_int8_t * buffer, u_int32_t nbytes)
 241 {
 242         u_int i;
 243
 244         for (i = 0; i < nbytes; i++) {
 245                 buffer[i] = read_eprom_byte(base, prom_offset);
 246                 ++prom_offset;
 247                 osp_MicroDelay(CYCLE_DELAY);
 248         }
 249 }