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1// SPDX-License-Identifier: GPL-2.0-only2#include <linux/kernel.h>3#include <linux/module.h>4#include <linux/slab.h>5#include <linux/delay.h>6#include <linux/ioport.h>7#include <linux/mtd/mtd.h>8#include <linux/platform_device.h>9#include <linux/bcma/bcma.h>10 11#include "bcm47xxsflash.h"12 13MODULE_LICENSE("GPL");14MODULE_DESCRIPTION("Serial flash driver for BCMA bus");15 16static const char * const probes[] = { "bcm47xxpart", NULL };17 18/**************************************************19 * Various helpers20 **************************************************/21 22static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode)23{24 int i;25 26 b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode);27 for (i = 0; i < 1000; i++) {28 if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) &29 BCMA_CC_FLASHCTL_BUSY))30 return;31 cpu_relax();32 }33 pr_err("Control command failed (timeout)!\n");34}35 36static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout)37{38 unsigned long deadline = jiffies + timeout;39 40 do {41 switch (b47s->type) {42 case BCM47XXSFLASH_TYPE_ST:43 bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR);44 if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &45 SR_ST_WIP))46 return 0;47 break;48 case BCM47XXSFLASH_TYPE_ATMEL:49 bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS);50 if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) &51 SR_AT_READY)52 return 0;53 break;54 }55 56 cpu_relax();57 udelay(1);58 } while (!time_after_eq(jiffies, deadline));59 60 pr_err("Timeout waiting for flash to be ready!\n");61 62 return -EBUSY;63}64 65/**************************************************66 * MTD ops67 **************************************************/68 69static int bcm47xxsflash_erase(struct mtd_info *mtd, struct erase_info *erase)70{71 struct bcm47xxsflash *b47s = mtd->priv;72 73 switch (b47s->type) {74 case BCM47XXSFLASH_TYPE_ST:75 bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);76 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr);77 /* Newer flashes have "sub-sectors" which can be erased78 * independently with a new command: ST_SSE. The ST_SE command79 * erases 64KB just as before.80 */81 if (b47s->blocksize < (64 * 1024))82 bcm47xxsflash_cmd(b47s, OPCODE_ST_SSE);83 else84 bcm47xxsflash_cmd(b47s, OPCODE_ST_SE);85 break;86 case BCM47XXSFLASH_TYPE_ATMEL:87 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr << 1);88 bcm47xxsflash_cmd(b47s, OPCODE_AT_PAGE_ERASE);89 break;90 }91 92 return bcm47xxsflash_poll(b47s, HZ);93}94 95static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len,96 size_t *retlen, u_char *buf)97{98 struct bcm47xxsflash *b47s = mtd->priv;99 size_t orig_len = len;100 101 /* Check address range */102 if ((from + len) > mtd->size)103 return -EINVAL;104 105 /* Read as much as possible using fast MMIO window */106 if (from < BCM47XXSFLASH_WINDOW_SZ) {107 size_t memcpy_len;108 109 memcpy_len = min(len, (size_t)(BCM47XXSFLASH_WINDOW_SZ - from));110 memcpy_fromio(buf, b47s->window + from, memcpy_len);111 from += memcpy_len;112 len -= memcpy_len;113 buf += memcpy_len;114 }115 116 /* Use indirect access for content out of the window */117 for (; len; len--) {118 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, from++);119 bcm47xxsflash_cmd(b47s, OPCODE_ST_READ4B);120 *buf++ = b47s->cc_read(b47s, BCMA_CC_FLASHDATA);121 }122 123 *retlen = orig_len;124 125 return orig_len;126}127 128static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len,129 const u_char *buf)130{131 struct bcm47xxsflash *b47s = mtd->priv;132 int written = 0;133 134 /* Enable writes */135 bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN);136 137 /* Write first byte */138 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, offset);139 b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);140 141 /* Program page */142 if (b47s->bcma_cc->core->id.rev < 20) {143 bcm47xxsflash_cmd(b47s, OPCODE_ST_PP);144 return 1; /* 1B written */145 }146 147 /* Program page and set CSA (on newer chips we can continue writing) */148 bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | OPCODE_ST_PP);149 offset++;150 len--;151 written++;152 153 while (len > 0) {154 /* Page boundary, another function call is needed */155 if ((offset & 0xFF) == 0)156 break;157 158 bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | *buf++);159 offset++;160 len--;161 written++;162 }163 164 /* All done, drop CSA & poll */165 b47s->cc_write(b47s, BCMA_CC_FLASHCTL, 0);166 udelay(1);167 if (bcm47xxsflash_poll(b47s, HZ / 10))168 pr_err("Flash rejected dropping CSA\n");169 170 return written;171}172 173static int bcm47xxsflash_write_at(struct mtd_info *mtd, u32 offset, size_t len,174 const u_char *buf)175{176 struct bcm47xxsflash *b47s = mtd->priv;177 u32 mask = b47s->blocksize - 1;178 u32 page = (offset & ~mask) << 1;179 u32 byte = offset & mask;180 int written = 0;181 182 /* If we don't overwrite whole page, read it to the buffer first */183 if (byte || (len < b47s->blocksize)) {184 int err;185 186 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);187 bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_LOAD);188 /* 250 us for AT45DB321B */189 err = bcm47xxsflash_poll(b47s, HZ / 1000);190 if (err) {191 pr_err("Timeout reading page 0x%X info buffer\n", page);192 return err;193 }194 }195 196 /* Change buffer content with our data */197 while (len > 0) {198 /* Page boundary, another function call is needed */199 if (byte == b47s->blocksize)200 break;201 202 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, byte++);203 b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++);204 bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_WRITE);205 len--;206 written++;207 }208 209 /* Program page with the buffer content */210 b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page);211 bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_PROGRAM);212 213 return written;214}215 216static int bcm47xxsflash_write(struct mtd_info *mtd, loff_t to, size_t len,217 size_t *retlen, const u_char *buf)218{219 struct bcm47xxsflash *b47s = mtd->priv;220 int written;221 222 /* Writing functions can return without writing all passed data, for223 * example when the hardware is too old or when we git page boundary.224 */225 while (len > 0) {226 switch (b47s->type) {227 case BCM47XXSFLASH_TYPE_ST:228 written = bcm47xxsflash_write_st(mtd, to, len, buf);229 break;230 case BCM47XXSFLASH_TYPE_ATMEL:231 written = bcm47xxsflash_write_at(mtd, to, len, buf);232 break;233 default:234 BUG_ON(1);235 }236 if (written < 0) {237 pr_err("Error writing at offset 0x%llX\n", to);238 return written;239 }240 to += (loff_t)written;241 len -= written;242 *retlen += written;243 buf += written;244 }245 246 return 0;247}248 249static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s,250 struct device *dev)251{252 struct mtd_info *mtd = &b47s->mtd;253 254 mtd->priv = b47s;255 mtd->dev.parent = dev;256 mtd->name = "bcm47xxsflash";257 258 mtd->type = MTD_NORFLASH;259 mtd->flags = MTD_CAP_NORFLASH;260 mtd->size = b47s->size;261 mtd->erasesize = b47s->blocksize;262 mtd->writesize = 1;263 mtd->writebufsize = 1;264 265 mtd->_erase = bcm47xxsflash_erase;266 mtd->_read = bcm47xxsflash_read;267 mtd->_write = bcm47xxsflash_write;268}269 270/**************************************************271 * BCMA272 **************************************************/273 274static int bcm47xxsflash_bcma_cc_read(struct bcm47xxsflash *b47s, u16 offset)275{276 return bcma_cc_read32(b47s->bcma_cc, offset);277}278 279static void bcm47xxsflash_bcma_cc_write(struct bcm47xxsflash *b47s, u16 offset,280 u32 value)281{282 bcma_cc_write32(b47s->bcma_cc, offset, value);283}284 285static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)286{287 struct device *dev = &pdev->dev;288 struct bcma_sflash *sflash = dev_get_platdata(dev);289 struct bcm47xxsflash *b47s;290 struct resource *res;291 int err;292 293 b47s = devm_kzalloc(dev, sizeof(*b47s), GFP_KERNEL);294 if (!b47s)295 return -ENOMEM;296 297 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);298 if (!res) {299 dev_err(dev, "invalid resource\n");300 return -EINVAL;301 }302 if (!devm_request_mem_region(dev, res->start, resource_size(res),303 res->name)) {304 dev_err(dev, "can't request region for resource %pR\n", res);305 return -EBUSY;306 }307 308 b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash);309 b47s->cc_read = bcm47xxsflash_bcma_cc_read;310 b47s->cc_write = bcm47xxsflash_bcma_cc_write;311 312 /*313 * On old MIPS devices cache was magically invalidated when needed,314 * allowing us to use cached access and gain some performance. Trying315 * the same on ARM based BCM53573 results in flash corruptions, we need316 * to use uncached access for it.317 *318 * It may be arch specific, but right now there is only 1 ARM SoC using319 * this driver, so let's follow Broadcom's reference code and check320 * ChipCommon revision.321 */322 if (b47s->bcma_cc->core->id.rev == 54)323 b47s->window = ioremap(res->start, resource_size(res));324 else325 b47s->window = ioremap_cache(res->start, resource_size(res));326 if (!b47s->window) {327 dev_err(dev, "ioremap failed for resource %pR\n", res);328 return -ENOMEM;329 }330 331 switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) {332 case BCMA_CC_FLASHT_STSER:333 b47s->type = BCM47XXSFLASH_TYPE_ST;334 break;335 case BCMA_CC_FLASHT_ATSER:336 b47s->type = BCM47XXSFLASH_TYPE_ATMEL;337 break;338 }339 340 b47s->blocksize = sflash->blocksize;341 b47s->numblocks = sflash->numblocks;342 b47s->size = sflash->size;343 bcm47xxsflash_fill_mtd(b47s, &pdev->dev);344 345 platform_set_drvdata(pdev, b47s);346 347 err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0);348 if (err) {349 pr_err("Failed to register MTD device: %d\n", err);350 iounmap(b47s->window);351 return err;352 }353 354 if (bcm47xxsflash_poll(b47s, HZ / 10))355 pr_warn("Serial flash busy\n");356 357 return 0;358}359 360static void bcm47xxsflash_bcma_remove(struct platform_device *pdev)361{362 struct bcm47xxsflash *b47s = platform_get_drvdata(pdev);363 364 mtd_device_unregister(&b47s->mtd);365 iounmap(b47s->window);366}367 368static struct platform_driver bcma_sflash_driver = {369 .probe = bcm47xxsflash_bcma_probe,370 .remove_new = bcm47xxsflash_bcma_remove,371 .driver = {372 .name = "bcma_sflash",373 },374};375 376/**************************************************377 * Init378 **************************************************/379 380module_platform_driver(bcma_sflash_driver);381