| // SPDX-License-Identifier: GPL-2.0-only |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| #include <linux/delay.h> |
| #include <linux/ioport.h> |
| #include <linux/mtd/mtd.h> |
| #include <linux/platform_device.h> |
| #include <linux/bcma/bcma.h> |
| |
| #include "bcm47xxsflash.h" |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("Serial flash driver for BCMA bus"); |
| |
| static const char * const probes[] = { "bcm47xxpart", NULL }; |
| |
| /************************************************** |
| * Various helpers |
| **************************************************/ |
| |
| static void bcm47xxsflash_cmd(struct bcm47xxsflash *b47s, u32 opcode) |
| { |
| int i; |
| |
| b47s->cc_write(b47s, BCMA_CC_FLASHCTL, BCMA_CC_FLASHCTL_START | opcode); |
| for (i = 0; i < 1000; i++) { |
| if (!(b47s->cc_read(b47s, BCMA_CC_FLASHCTL) & |
| BCMA_CC_FLASHCTL_BUSY)) |
| return; |
| cpu_relax(); |
| } |
| pr_err("Control command failed (timeout)!\n"); |
| } |
| |
| static int bcm47xxsflash_poll(struct bcm47xxsflash *b47s, int timeout) |
| { |
| unsigned long deadline = jiffies + timeout; |
| |
| do { |
| switch (b47s->type) { |
| case BCM47XXSFLASH_TYPE_ST: |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_RDSR); |
| if (!(b47s->cc_read(b47s, BCMA_CC_FLASHDATA) & |
| SR_ST_WIP)) |
| return 0; |
| break; |
| case BCM47XXSFLASH_TYPE_ATMEL: |
| bcm47xxsflash_cmd(b47s, OPCODE_AT_STATUS); |
| if (b47s->cc_read(b47s, BCMA_CC_FLASHDATA) & |
| SR_AT_READY) |
| return 0; |
| break; |
| } |
| |
| cpu_relax(); |
| udelay(1); |
| } while (!time_after_eq(jiffies, deadline)); |
| |
| pr_err("Timeout waiting for flash to be ready!\n"); |
| |
| return -EBUSY; |
| } |
| |
| /************************************************** |
| * MTD ops |
| **************************************************/ |
| |
| static int bcm47xxsflash_erase(struct mtd_info *mtd, struct erase_info *erase) |
| { |
| struct bcm47xxsflash *b47s = mtd->priv; |
| |
| switch (b47s->type) { |
| case BCM47XXSFLASH_TYPE_ST: |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN); |
| b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr); |
| /* Newer flashes have "sub-sectors" which can be erased |
| * independently with a new command: ST_SSE. The ST_SE command |
| * erases 64KB just as before. |
| */ |
| if (b47s->blocksize < (64 * 1024)) |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_SSE); |
| else |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_SE); |
| break; |
| case BCM47XXSFLASH_TYPE_ATMEL: |
| b47s->cc_write(b47s, BCMA_CC_FLASHADDR, erase->addr << 1); |
| bcm47xxsflash_cmd(b47s, OPCODE_AT_PAGE_ERASE); |
| break; |
| } |
| |
| return bcm47xxsflash_poll(b47s, HZ); |
| } |
| |
| static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len, |
| size_t *retlen, u_char *buf) |
| { |
| struct bcm47xxsflash *b47s = mtd->priv; |
| size_t orig_len = len; |
| |
| /* Check address range */ |
| if ((from + len) > mtd->size) |
| return -EINVAL; |
| |
| /* Read as much as possible using fast MMIO window */ |
| if (from < BCM47XXSFLASH_WINDOW_SZ) { |
| size_t memcpy_len; |
| |
| memcpy_len = min(len, (size_t)(BCM47XXSFLASH_WINDOW_SZ - from)); |
| memcpy_fromio(buf, b47s->window + from, memcpy_len); |
| from += memcpy_len; |
| len -= memcpy_len; |
| buf += memcpy_len; |
| } |
| |
| /* Use indirect access for content out of the window */ |
| for (; len; len--) { |
| b47s->cc_write(b47s, BCMA_CC_FLASHADDR, from++); |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_READ4B); |
| *buf++ = b47s->cc_read(b47s, BCMA_CC_FLASHDATA); |
| } |
| |
| *retlen = orig_len; |
| |
| return orig_len; |
| } |
| |
| static int bcm47xxsflash_write_st(struct mtd_info *mtd, u32 offset, size_t len, |
| const u_char *buf) |
| { |
| struct bcm47xxsflash *b47s = mtd->priv; |
| int written = 0; |
| |
| /* Enable writes */ |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_WREN); |
| |
| /* Write first byte */ |
| b47s->cc_write(b47s, BCMA_CC_FLASHADDR, offset); |
| b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++); |
| |
| /* Program page */ |
| if (b47s->bcma_cc->core->id.rev < 20) { |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_PP); |
| return 1; /* 1B written */ |
| } |
| |
| /* Program page and set CSA (on newer chips we can continue writing) */ |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | OPCODE_ST_PP); |
| offset++; |
| len--; |
| written++; |
| |
| while (len > 0) { |
| /* Page boundary, another function call is needed */ |
| if ((offset & 0xFF) == 0) |
| break; |
| |
| bcm47xxsflash_cmd(b47s, OPCODE_ST_CSA | *buf++); |
| offset++; |
| len--; |
| written++; |
| } |
| |
| /* All done, drop CSA & poll */ |
| b47s->cc_write(b47s, BCMA_CC_FLASHCTL, 0); |
| udelay(1); |
| if (bcm47xxsflash_poll(b47s, HZ / 10)) |
| pr_err("Flash rejected dropping CSA\n"); |
| |
| return written; |
| } |
| |
| static int bcm47xxsflash_write_at(struct mtd_info *mtd, u32 offset, size_t len, |
| const u_char *buf) |
| { |
| struct bcm47xxsflash *b47s = mtd->priv; |
| u32 mask = b47s->blocksize - 1; |
| u32 page = (offset & ~mask) << 1; |
| u32 byte = offset & mask; |
| int written = 0; |
| |
| /* If we don't overwrite whole page, read it to the buffer first */ |
| if (byte || (len < b47s->blocksize)) { |
| int err; |
| |
| b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page); |
| bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_LOAD); |
| /* 250 us for AT45DB321B */ |
| err = bcm47xxsflash_poll(b47s, HZ / 1000); |
| if (err) { |
| pr_err("Timeout reading page 0x%X info buffer\n", page); |
| return err; |
| } |
| } |
| |
| /* Change buffer content with our data */ |
| while (len > 0) { |
| /* Page boundary, another function call is needed */ |
| if (byte == b47s->blocksize) |
| break; |
| |
| b47s->cc_write(b47s, BCMA_CC_FLASHADDR, byte++); |
| b47s->cc_write(b47s, BCMA_CC_FLASHDATA, *buf++); |
| bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_WRITE); |
| len--; |
| written++; |
| } |
| |
| /* Program page with the buffer content */ |
| b47s->cc_write(b47s, BCMA_CC_FLASHADDR, page); |
| bcm47xxsflash_cmd(b47s, OPCODE_AT_BUF1_PROGRAM); |
| |
| return written; |
| } |
| |
| static int bcm47xxsflash_write(struct mtd_info *mtd, loff_t to, size_t len, |
| size_t *retlen, const u_char *buf) |
| { |
| struct bcm47xxsflash *b47s = mtd->priv; |
| int written; |
| |
| /* Writing functions can return without writing all passed data, for |
| * example when the hardware is too old or when we git page boundary. |
| */ |
| while (len > 0) { |
| switch (b47s->type) { |
| case BCM47XXSFLASH_TYPE_ST: |
| written = bcm47xxsflash_write_st(mtd, to, len, buf); |
| break; |
| case BCM47XXSFLASH_TYPE_ATMEL: |
| written = bcm47xxsflash_write_at(mtd, to, len, buf); |
| break; |
| default: |
| BUG_ON(1); |
| } |
| if (written < 0) { |
| pr_err("Error writing at offset 0x%llX\n", to); |
| return written; |
| } |
| to += (loff_t)written; |
| len -= written; |
| *retlen += written; |
| buf += written; |
| } |
| |
| return 0; |
| } |
| |
| static void bcm47xxsflash_fill_mtd(struct bcm47xxsflash *b47s, |
| struct device *dev) |
| { |
| struct mtd_info *mtd = &b47s->mtd; |
| |
| mtd->priv = b47s; |
| mtd->dev.parent = dev; |
| mtd->name = "bcm47xxsflash"; |
| |
| mtd->type = MTD_NORFLASH; |
| mtd->flags = MTD_CAP_NORFLASH; |
| mtd->size = b47s->size; |
| mtd->erasesize = b47s->blocksize; |
| mtd->writesize = 1; |
| mtd->writebufsize = 1; |
| |
| mtd->_erase = bcm47xxsflash_erase; |
| mtd->_read = bcm47xxsflash_read; |
| mtd->_write = bcm47xxsflash_write; |
| } |
| |
| /************************************************** |
| * BCMA |
| **************************************************/ |
| |
| static int bcm47xxsflash_bcma_cc_read(struct bcm47xxsflash *b47s, u16 offset) |
| { |
| return bcma_cc_read32(b47s->bcma_cc, offset); |
| } |
| |
| static void bcm47xxsflash_bcma_cc_write(struct bcm47xxsflash *b47s, u16 offset, |
| u32 value) |
| { |
| bcma_cc_write32(b47s->bcma_cc, offset, value); |
| } |
| |
| static int bcm47xxsflash_bcma_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct bcma_sflash *sflash = dev_get_platdata(dev); |
| struct bcm47xxsflash *b47s; |
| struct resource *res; |
| int err; |
| |
| b47s = devm_kzalloc(dev, sizeof(*b47s), GFP_KERNEL); |
| if (!b47s) |
| return -ENOMEM; |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| if (!res) { |
| dev_err(dev, "invalid resource\n"); |
| return -EINVAL; |
| } |
| if (!devm_request_mem_region(dev, res->start, resource_size(res), |
| res->name)) { |
| dev_err(dev, "can't request region for resource %pR\n", res); |
| return -EBUSY; |
| } |
| |
| b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash); |
| b47s->cc_read = bcm47xxsflash_bcma_cc_read; |
| b47s->cc_write = bcm47xxsflash_bcma_cc_write; |
| |
| /* |
| * On old MIPS devices cache was magically invalidated when needed, |
| * allowing us to use cached access and gain some performance. Trying |
| * the same on ARM based BCM53573 results in flash corruptions, we need |
| * to use uncached access for it. |
| * |
| * It may be arch specific, but right now there is only 1 ARM SoC using |
| * this driver, so let's follow Broadcom's reference code and check |
| * ChipCommon revision. |
| */ |
| if (b47s->bcma_cc->core->id.rev == 54) |
| b47s->window = ioremap(res->start, resource_size(res)); |
| else |
| b47s->window = ioremap_cache(res->start, resource_size(res)); |
| if (!b47s->window) { |
| dev_err(dev, "ioremap failed for resource %pR\n", res); |
| return -ENOMEM; |
| } |
| |
| switch (b47s->bcma_cc->capabilities & BCMA_CC_CAP_FLASHT) { |
| case BCMA_CC_FLASHT_STSER: |
| b47s->type = BCM47XXSFLASH_TYPE_ST; |
| break; |
| case BCMA_CC_FLASHT_ATSER: |
| b47s->type = BCM47XXSFLASH_TYPE_ATMEL; |
| break; |
| } |
| |
| b47s->blocksize = sflash->blocksize; |
| b47s->numblocks = sflash->numblocks; |
| b47s->size = sflash->size; |
| bcm47xxsflash_fill_mtd(b47s, &pdev->dev); |
| |
| platform_set_drvdata(pdev, b47s); |
| |
| err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0); |
| if (err) { |
| pr_err("Failed to register MTD device: %d\n", err); |
| iounmap(b47s->window); |
| return err; |
| } |
| |
| if (bcm47xxsflash_poll(b47s, HZ / 10)) |
| pr_warn("Serial flash busy\n"); |
| |
| return 0; |
| } |
| |
| static void bcm47xxsflash_bcma_remove(struct platform_device *pdev) |
| { |
| struct bcm47xxsflash *b47s = platform_get_drvdata(pdev); |
| |
| mtd_device_unregister(&b47s->mtd); |
| iounmap(b47s->window); |
| } |
| |
| static struct platform_driver bcma_sflash_driver = { |
| .probe = bcm47xxsflash_bcma_probe, |
| .remove_new = bcm47xxsflash_bcma_remove, |
| .driver = { |
| .name = "bcma_sflash", |
| }, |
| }; |
| |
| /************************************************** |
| * Init |
| **************************************************/ |
| |
| module_platform_driver(bcma_sflash_driver); |