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1// SPDX-License-Identifier: GPL-2.02/*3 * this file included by nicstar.c4 */5 6/*7 * nicstarmac.c8 * Read this ForeRunner's MAC address from eprom/eeprom9 */10 11#include <linux/kernel.h>12 13typedef void __iomem *virt_addr_t;14 15#define CYCLE_DELAY 516 17#define osp_MicroDelay(microsec) {unsigned long useconds = (microsec); \18 udelay((useconds));}19/*20 * The following tables represent the timing diagrams found in21 * the Data Sheet for the Xicor X25020 EEProm. The #defines below22 * represent the bits in the NICStAR's General Purpose register23 * that must be toggled for the corresponding actions on the EEProm24 * to occur.25 */26 27/* Write Data To EEProm from SI line on rising edge of CLK */28/* Read Data From EEProm on falling edge of CLK */29 30#define CS_HIGH 0x0002 /* Chip select high */31#define CS_LOW 0x0000 /* Chip select low (active low) */32#define CLK_HIGH 0x0004 /* Clock high */33#define CLK_LOW 0x0000 /* Clock low */34#define SI_HIGH 0x0001 /* Serial input data high */35#define SI_LOW 0x0000 /* Serial input data low */36 37/* Read Status Register = 0000 0101b */38#if 039static u_int32_t rdsrtab[] = {40 CS_HIGH | CLK_HIGH,41 CS_LOW | CLK_LOW,42 CLK_HIGH, /* 0 */43 CLK_LOW,44 CLK_HIGH, /* 0 */45 CLK_LOW,46 CLK_HIGH, /* 0 */47 CLK_LOW,48 CLK_HIGH, /* 0 */49 CLK_LOW,50 CLK_HIGH, /* 0 */51 CLK_LOW | SI_HIGH,52 CLK_HIGH | SI_HIGH, /* 1 */53 CLK_LOW | SI_LOW,54 CLK_HIGH, /* 0 */55 CLK_LOW | SI_HIGH,56 CLK_HIGH | SI_HIGH /* 1 */57};58#endif /* 0 */59 60/* Read from EEPROM = 0000 0011b */61static u_int32_t readtab[] = {62 /*63 CS_HIGH | CLK_HIGH,64 */65 CS_LOW | CLK_LOW,66 CLK_HIGH, /* 0 */67 CLK_LOW,68 CLK_HIGH, /* 0 */69 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 | SI_HIGH,78 CLK_HIGH | SI_HIGH, /* 1 */79 CLK_LOW | SI_HIGH,80 CLK_HIGH | SI_HIGH /* 1 */81};82 83/* Clock to read from/write to the eeprom */84static u_int32_t clocktab[] = {85 CLK_LOW,86 CLK_HIGH,87 CLK_LOW,88 CLK_HIGH,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_LOW102};103 104#define NICSTAR_REG_WRITE(bs, reg, val) \105 while ( readl(bs + STAT) & 0x0200 ) ; \106 writel((val),(base)+(reg))107#define NICSTAR_REG_READ(bs, reg) \108 readl((base)+(reg))109#define NICSTAR_REG_GENERAL_PURPOSE GP110 111/*112 * This routine will clock the Read_Status_reg function into the X2520113 * eeprom, then pull the result from bit 16 of the NicSTaR's General Purpose 114 * register. 115 */116#if 0117u_int32_t nicstar_read_eprom_status(virt_addr_t base)118{119 u_int32_t val;120 u_int32_t rbyte;121 int32_t i, j;122 123 /* Send read instruction */124 val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;125 126 for (i = 0; i < ARRAY_SIZE(rdsrtab); i++) {127 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,128 (val | rdsrtab[i]));129 osp_MicroDelay(CYCLE_DELAY);130 }131 132 /* Done sending instruction - now pull data off of bit 16, MSB first */133 /* Data clocked out of eeprom on falling edge of clock */134 135 rbyte = 0;136 for (i = 7, j = 0; i >= 0; i--) {137 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,138 (val | clocktab[j++]));139 rbyte |= (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE)140 & 0x00010000) >> 16) << i);141 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,142 (val | clocktab[j++]));143 osp_MicroDelay(CYCLE_DELAY);144 }145 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2);146 osp_MicroDelay(CYCLE_DELAY);147 return rbyte;148}149#endif /* 0 */150 151/*152 * This routine will clock the Read_data function into the X2520153 * eeprom, followed by the address to read from, through the NicSTaR's General154 * Purpose register. 155 */156 157static u_int8_t read_eprom_byte(virt_addr_t base, u_int8_t offset)158{159 u_int32_t val = 0;160 int i, j = 0;161 u_int8_t tempread = 0;162 163 val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;164 165 /* Send READ instruction */166 for (i = 0; i < ARRAY_SIZE(readtab); i++) {167 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,168 (val | readtab[i]));169 osp_MicroDelay(CYCLE_DELAY);170 }171 172 /* Next, we need to send the byte address to read from */173 for (i = 7; i >= 0; i--) {174 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,175 (val | clocktab[j++] | ((offset >> i) & 1)));176 osp_MicroDelay(CYCLE_DELAY);177 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,178 (val | clocktab[j++] | ((offset >> i) & 1)));179 osp_MicroDelay(CYCLE_DELAY);180 }181 182 j = 0;183 184 /* Now, we can read data from the eeprom by clocking it in */185 for (i = 7; i >= 0; i--) {186 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,187 (val | clocktab[j++]));188 osp_MicroDelay(CYCLE_DELAY);189 tempread |=190 (((NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE)191 & 0x00010000) >> 16) << i);192 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,193 (val | clocktab[j++]));194 osp_MicroDelay(CYCLE_DELAY);195 }196 197 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE, 2);198 osp_MicroDelay(CYCLE_DELAY);199 return tempread;200}201 202static void nicstar_init_eprom(virt_addr_t base)203{204 u_int32_t val;205 206 /*207 * turn chip select off208 */209 val = NICSTAR_REG_READ(base, NICSTAR_REG_GENERAL_PURPOSE) & 0xFFFFFFF0;210 211 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,212 (val | CS_HIGH | CLK_HIGH));213 osp_MicroDelay(CYCLE_DELAY);214 215 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,216 (val | CS_HIGH | CLK_LOW));217 osp_MicroDelay(CYCLE_DELAY);218 219 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,220 (val | CS_HIGH | CLK_HIGH));221 osp_MicroDelay(CYCLE_DELAY);222 223 NICSTAR_REG_WRITE(base, NICSTAR_REG_GENERAL_PURPOSE,224 (val | CS_HIGH | CLK_LOW));225 osp_MicroDelay(CYCLE_DELAY);226}227 228/*229 * This routine will be the interface to the ReadPromByte function230 * above.231 */232 233static void234nicstar_read_eprom(virt_addr_t base,235 u_int8_t prom_offset, u_int8_t * buffer, u_int32_t nbytes)236{237 u_int i;238 239 for (i = 0; i < nbytes; i++) {240 buffer[i] = read_eprom_byte(base, prom_offset);241 ++prom_offset;242 osp_MicroDelay(CYCLE_DELAY);243 }244}245