From 2af7c653993199fb32dc6d9504064a0c9c57e5d6 Mon Sep 17 00:00:00 2001 From: Simon Kagstrom Date: Mon, 5 Oct 2009 15:55:52 +0200 Subject: [PATCH] mtd: Add panic_write for NAND flashes This is a quick and dirty patch to add panic_write for NAND flashes. The patch seems to work OK on my CRIS board running a 2.6.26 kernel with a ID: 0x20, Chip ID: 0xf1 (ST Micro NAND 128MiB 3,3V 8-bit), and also on a OpenRD base (Marvell Kirkwood) board with a Toshiba NAND 512MiB 3,3V 8-bit flash with 2.6.32-pre1. Signed-off-by: Edgar E. Iglesias Signed-off-by: Simon Kagstrom Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/nand/nand_base.c | 128 ++++++++++++++++++++++++++++++++--- 1 file changed, 120 insertions(+), 8 deletions(-) diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c index 2957cc70da3..ba06473326d 100644 --- a/drivers/mtd/nand/nand_base.c +++ b/drivers/mtd/nand/nand_base.c @@ -428,6 +428,28 @@ static int nand_block_checkbad(struct mtd_info *mtd, loff_t ofs, int getchip, return nand_isbad_bbt(mtd, ofs, allowbbt); } +/** + * panic_nand_wait_ready - [GENERIC] Wait for the ready pin after commands. + * @mtd: MTD device structure + * @timeo: Timeout + * + * Helper function for nand_wait_ready used when needing to wait in interrupt + * context. + */ +static void panic_nand_wait_ready(struct mtd_info *mtd, unsigned long timeo) +{ + struct nand_chip *chip = mtd->priv; + int i; + + /* Wait for the device to get ready */ + for (i = 0; i < timeo; i++) { + if (chip->dev_ready(mtd)) + break; + touch_softlockup_watchdog(); + mdelay(1); + } +} + /* * Wait for the ready pin, after a command * The timeout is catched later. @@ -437,6 +459,10 @@ void nand_wait_ready(struct mtd_info *mtd) struct nand_chip *chip = mtd->priv; unsigned long timeo = jiffies + 2; + /* 400ms timeout */ + if (in_interrupt() || oops_in_progress) + return panic_nand_wait_ready(mtd, 400); + led_trigger_event(nand_led_trigger, LED_FULL); /* wait until command is processed or timeout occures */ do { @@ -671,6 +697,22 @@ static void nand_command_lp(struct mtd_info *mtd, unsigned int command, nand_wait_ready(mtd); } +/** + * panic_nand_get_device - [GENERIC] Get chip for selected access + * @chip: the nand chip descriptor + * @mtd: MTD device structure + * @new_state: the state which is requested + * + * Used when in panic, no locks are taken. + */ +static void panic_nand_get_device(struct nand_chip *chip, + struct mtd_info *mtd, int new_state) +{ + /* Hardware controller shared among independend devices */ + chip->controller->active = chip; + chip->state = new_state; +} + /** * nand_get_device - [GENERIC] Get chip for selected access * @chip: the nand chip descriptor @@ -709,6 +751,32 @@ nand_get_device(struct nand_chip *chip, struct mtd_info *mtd, int new_state) goto retry; } +/** + * panic_nand_wait - [GENERIC] wait until the command is done + * @mtd: MTD device structure + * @chip: NAND chip structure + * @timeo: Timeout + * + * Wait for command done. This is a helper function for nand_wait used when + * we are in interrupt context. May happen when in panic and trying to write + * an oops trough mtdoops. + */ +static void panic_nand_wait(struct mtd_info *mtd, struct nand_chip *chip, + unsigned long timeo) +{ + int i; + for (i = 0; i < timeo; i++) { + if (chip->dev_ready) { + if (chip->dev_ready(mtd)) + break; + } else { + if (chip->read_byte(mtd) & NAND_STATUS_READY) + break; + } + mdelay(1); + } +} + /** * nand_wait - [DEFAULT] wait until the command is done * @mtd: MTD device structure @@ -740,15 +808,19 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip) else chip->cmdfunc(mtd, NAND_CMD_STATUS, -1, -1); - while (time_before(jiffies, timeo)) { - if (chip->dev_ready) { - if (chip->dev_ready(mtd)) - break; - } else { - if (chip->read_byte(mtd) & NAND_STATUS_READY) - break; + if (in_interrupt() || oops_in_progress) + panic_nand_wait(mtd, chip, timeo); + else { + while (time_before(jiffies, timeo)) { + if (chip->dev_ready) { + if (chip->dev_ready(mtd)) + break; + } else { + if (chip->read_byte(mtd) & NAND_STATUS_READY) + break; + } + cond_resched(); } - cond_resched(); } led_trigger_event(nand_led_trigger, LED_OFF); @@ -1948,6 +2020,45 @@ static int nand_do_write_ops(struct mtd_info *mtd, loff_t to, return ret; } +/** + * panic_nand_write - [MTD Interface] NAND write with ECC + * @mtd: MTD device structure + * @to: offset to write to + * @len: number of bytes to write + * @retlen: pointer to variable to store the number of written bytes + * @buf: the data to write + * + * NAND write with ECC. Used when performing writes in interrupt context, this + * may for example be called by mtdoops when writing an oops while in panic. + */ +static int panic_nand_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const uint8_t *buf) +{ + struct nand_chip *chip = mtd->priv; + int ret; + + /* Do not allow reads past end of device */ + if ((to + len) > mtd->size) + return -EINVAL; + if (!len) + return 0; + + /* Wait for the device to get ready. */ + panic_nand_wait(mtd, chip, 400); + + /* Grab the device. */ + panic_nand_get_device(chip, mtd, FL_WRITING); + + chip->ops.len = len; + chip->ops.datbuf = (uint8_t *)buf; + chip->ops.oobbuf = NULL; + + ret = nand_do_write_ops(mtd, to, &chip->ops); + + *retlen = chip->ops.retlen; + return ret; +} + /** * nand_write - [MTD Interface] NAND write with ECC * @mtd: MTD device structure @@ -2877,6 +2988,7 @@ int nand_scan_tail(struct mtd_info *mtd) mtd->unpoint = NULL; mtd->read = nand_read; mtd->write = nand_write; + mtd->panic_write = panic_nand_write; mtd->read_oob = nand_read_oob; mtd->write_oob = nand_write_oob; mtd->sync = nand_sync; -- 2.41.0