diff options
Diffstat (limited to 'drivers/mtd/devices/bcm47xxsflash.c')
| -rw-r--r-- | drivers/mtd/devices/bcm47xxsflash.c | 327 |
1 files changed, 281 insertions, 46 deletions
diff --git a/drivers/mtd/devices/bcm47xxsflash.c b/drivers/mtd/devices/bcm47xxsflash.c index 4714584aa99..77de29bc02b 100644 --- a/drivers/mtd/devices/bcm47xxsflash.c +++ b/drivers/mtd/devices/bcm47xxsflash.c @@ -1,105 +1,340 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/slab.h> +#include <linux/delay.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 *probes[] = { "bcm47xxpart", NULL }; +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; + int err; + + 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; + } + + err = bcm47xxsflash_poll(b47s, HZ); + if (err) + erase->state = MTD_ERASE_FAILED; + else + erase->state = MTD_ERASE_DONE; + + if (erase->callback) + erase->callback(erase); + + return err; +} static int bcm47xxsflash_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { - struct bcma_sflash *sflash = mtd->priv; + struct bcm47xxsflash *b47s = mtd->priv; /* Check address range */ if ((from + len) > mtd->size) return -EINVAL; - memcpy_fromio(buf, (void __iomem *)KSEG0ADDR(sflash->window + from), + memcpy_fromio(buf, (void __iomem *)KSEG0ADDR(b47s->window + from), len); + *retlen = len; return len; } -static void bcm47xxsflash_fill_mtd(struct bcma_sflash *sflash, - struct mtd_info *mtd) +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) { - mtd->priv = sflash; + 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 mtd_info *mtd = &b47s->mtd; + + mtd->priv = b47s; mtd->name = "bcm47xxsflash"; mtd->owner = THIS_MODULE; - mtd->type = MTD_ROM; - mtd->size = sflash->size; + + 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 + **************************************************/ - /* TODO: implement writing support and verify/change following code */ - mtd->flags = MTD_CAP_ROM; - mtd->writebufsize = mtd->writesize = 1; +static int bcm47xxsflash_bcma_cc_read(struct bcm47xxsflash *b47s, u16 offset) +{ + return bcma_cc_read32(b47s->bcma_cc, offset); } -static int bcm47xxsflash_probe(struct platform_device *pdev) +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 bcma_sflash *sflash = dev_get_platdata(&pdev->dev); + struct bcm47xxsflash *b47s; int err; - sflash->mtd = kzalloc(sizeof(struct mtd_info), GFP_KERNEL); - if (!sflash->mtd) { - err = -ENOMEM; - goto out; + b47s = devm_kzalloc(&pdev->dev, sizeof(*b47s), GFP_KERNEL); + if (!b47s) + return -ENOMEM; + sflash->priv = b47s; + + 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; + + 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; } - bcm47xxsflash_fill_mtd(sflash, sflash->mtd); - err = mtd_device_parse_register(sflash->mtd, probes, NULL, NULL, 0); + b47s->window = sflash->window; + b47s->blocksize = sflash->blocksize; + b47s->numblocks = sflash->numblocks; + b47s->size = sflash->size; + bcm47xxsflash_fill_mtd(b47s); + + err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0); if (err) { pr_err("Failed to register MTD device: %d\n", err); - goto err_dev_reg; + return err; } - return 0; + if (bcm47xxsflash_poll(b47s, HZ / 10)) + pr_warn("Serial flash busy\n"); -err_dev_reg: - kfree(sflash->mtd); -out: - return err; + return 0; } -static int bcm47xxsflash_remove(struct platform_device *pdev) +static int bcm47xxsflash_bcma_remove(struct platform_device *pdev) { struct bcma_sflash *sflash = dev_get_platdata(&pdev->dev); + struct bcm47xxsflash *b47s = sflash->priv; - mtd_device_unregister(sflash->mtd); - kfree(sflash->mtd); + mtd_device_unregister(&b47s->mtd); return 0; } static struct platform_driver bcma_sflash_driver = { - .remove = bcm47xxsflash_remove, + .probe = bcm47xxsflash_bcma_probe, + .remove = bcm47xxsflash_bcma_remove, .driver = { .name = "bcma_sflash", .owner = THIS_MODULE, }, }; -static int __init bcm47xxsflash_init(void) -{ - int err; - - err = platform_driver_probe(&bcma_sflash_driver, bcm47xxsflash_probe); - if (err) - pr_err("Failed to register BCMA serial flash driver: %d\n", - err); - - return err; -} - -static void __exit bcm47xxsflash_exit(void) -{ - platform_driver_unregister(&bcma_sflash_driver); -} +/************************************************** + * Init + **************************************************/ -module_init(bcm47xxsflash_init); -module_exit(bcm47xxsflash_exit); +module_platform_driver(bcma_sflash_driver); |