mtd: rawnand: marvell: Support panic_write for mtdoops

Under a panic context we can't get an interrupt. Actively poll for the
RB status when performing a panic_write.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200828011237.22066-1-chris.packham@alliedtelesis.co.nz

diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c
index f7ff8e9..8d76ef4 100644 (file)
--- a/drivers/mtd/nand/raw/marvell_nand.c
+++ b/drivers/mtd/nand/raw/marvell_nand.c
@@ -685,9 +685,31 @@ static int marvell_nfc_wait_cmdd(struct nand_chip *chip)
        return marvell_nfc_end_cmd(chip, cs_flag, "CMDD");
 }
 
+static int marvell_nfc_poll_status(struct marvell_nfc *nfc, u32 mask,
+                                  u32 expected_val, unsigned long timeout_ms)
+{
+       unsigned long limit;
+       u32 st;
+
+       limit = jiffies + msecs_to_jiffies(timeout_ms);
+       do {
+               st = readl_relaxed(nfc->regs + NDSR);
+               if (st & NDSR_RDY(1))
+                       st |= NDSR_RDY(0);
+
+               if ((st & mask) == expected_val)
+                       return 0;
+
+               cpu_relax();
+       } while (time_after(limit, jiffies));
+
+       return -ETIMEDOUT;
+}
+
 static int marvell_nfc_wait_op(struct nand_chip *chip, unsigned int timeout_ms)
 {
        struct marvell_nfc *nfc = to_marvell_nfc(chip->controller);
+       struct mtd_info *mtd = nand_to_mtd(chip);
        u32 pending;
        int ret;
 
@@ -695,12 +717,18 @@ static int marvell_nfc_wait_op(struct nand_chip *chip, unsigned int timeout_ms)
        if (!timeout_ms)
                timeout_ms = IRQ_TIMEOUT;
 
-       init_completion(&nfc->complete);
+       if (mtd->oops_panic_write) {
+               ret = marvell_nfc_poll_status(nfc, NDSR_RDY(0),
+                                             NDSR_RDY(0),
+                                             timeout_ms);
+       } else {
+               init_completion(&nfc->complete);
 
-       marvell_nfc_enable_int(nfc, NDCR_RDYM);
-       ret = wait_for_completion_timeout(&nfc->complete,
-                                         msecs_to_jiffies(timeout_ms));
-       marvell_nfc_disable_int(nfc, NDCR_RDYM);
+               marvell_nfc_enable_int(nfc, NDCR_RDYM);
+               ret = wait_for_completion_timeout(&nfc->complete,
+                                                 msecs_to_jiffies(timeout_ms));
+               marvell_nfc_disable_int(nfc, NDCR_RDYM);
+       }
        pending = marvell_nfc_clear_int(nfc, NDSR_RDY(0) | NDSR_RDY(1));
 
        /*