Re: [PATCH] mtd: rawnand: ingenic: Convert the driver to exec_op()

[Boris Brezillon <boris.brezillon@collabora.com>]

On Mon, 18 May 2020 19:50:04 +0200
Paul Cercueil <paul@crapouillou.net> wrote:

> Hi Boris,
> 
> Le lun. 18 mai 2020 à 18:56, Boris Brezillon 
> <boris.brezillon@collabora.com> a écrit :
> > Let's convert the driver to exec_op() to have one less driver relying
> > on the legacy interface.  
> 
> Great work, thanks for that.
> 
> However it does not work :( nand_scan() returns error -145.

Looks like the R/B signal is inverted. Can you try with the
following diff applied?

--->8---
diff --git a/drivers/mtd/nand/raw/ingenic/ingenic_nand_drv.c b/drivers/mtd/nand/raw/ingenic/ingenic_nand_drv.c
index dcecd54af20b..9206792629a8 100644
--- a/drivers/mtd/nand/raw/ingenic/ingenic_nand_drv.c
+++ b/drivers/mtd/nand/raw/ingenic/ingenic_nand_drv.c
@@ -249,6 +249,26 @@ static int ingenic_nand_attach_chip(struct nand_chip *chip)
        return 0;
 }
 
+static int ingenic_nand_gpio_waitrdy(struct gpio_desc *gpiod,
+                                    unsigned long timeout_ms)
+{
+       /*
+        * Wait until R/B pin indicates chip is ready or timeout occurs.
+        * +1 below is necessary because if we are now in the last fraction
+        * of jiffy and msecs_to_jiffies is 1 then we will wait only that
+        * small jiffy fraction - possibly leading to false timeout.
+       */
+       timeout_ms = jiffies + msecs_to_jiffies(timeout_ms) + 1;
+       do {
+               if (!gpiod_get_value_cansleep(gpiod))
+                       return 0;
+
+               cond_resched();
+       } while (time_before(jiffies, timeout_ms));
+
+       return !gpiod_get_value_cansleep(gpiod) ? 0 : -ETIMEDOUT;
+};
+
 static int ingenic_nand_exec_instr(struct nand_chip *chip,
                                   struct ingenic_nand_cs *cs,
                                   const struct nand_op_instr *instr)
@@ -294,8 +314,8 @@ static int ingenic_nand_exec_instr(struct nand_chip *chip,
                        return nand_soft_waitrdy(chip,
                                                 instr->ctx.waitrdy.timeout_ms);
 
-               return nand_gpio_waitrdy(chip, nand->busy_gpio,
-                                        instr->ctx.waitrdy.timeout_ms);
+               return ingenic_nand_gpio_waitrdy(nand->busy_gpio,
+                                                instr->ctx.waitrdy.timeout_ms);
        default:
                break;
        }
@@ -322,6 +342,9 @@ static int ingenic_nand_exec_op(struct nand_chip *chip,
                ret = ingenic_nand_exec_instr(chip, cs, &op->instrs[i]);
                if (ret)
                        break;
+
+               if (op->instrs[i].delay_ns)
+                       ndelay(op->instrs[i].delay_ns);
        }
        jz4780_nemc_assert(nfc->dev, cs->bank, false);
 

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