Hi Arseniy,
avkrasnov@xxxxxxxxxxxxxx wrote on Tue, 4 Jul 2023 15:46:18 +0300:
> On 04.07.2023 15:43, Miquel Raynal wrote:
> > Hi Arseniy,
> >
> > AVKrasnov@xxxxxxxxxxxxxx wrote on Thu, 8 Jun 2023 07:47:28 +0300:
> >
> >> If there is no wired ready/busy pin, classic way to wait for command
> >> completion is to use function 'nand_soft_waitrdy()'. Meson NAND has
> >> special command which allows to wait for NAND_STATUS_READY bit without
> >> reading status in a software loop (as 'nand_soft_waitrdy()' does). To
> >> use it send this command along with NAND_CMD_STATUS, then wait for an
> >> interrupt, and after interrupt send NAND_CMD_READ0. So this feature
> >> allows to use interrupt driven waiting without wired ready/busy pin.
> >>
> >> Suggested-by: Liang Yang <liang.yang@xxxxxxxxxxx>
> >> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
> >> ---
> >> drivers/mtd/nand/raw/meson_nand.c | 77 +++++++++++++++++++++++++++++--
> >> 1 file changed, 73 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> >> index 074e14225c06..9f05e113b4ea 100644
> >> --- a/drivers/mtd/nand/raw/meson_nand.c
> >> +++ b/drivers/mtd/nand/raw/meson_nand.c
> >> @@ -38,6 +38,7 @@
> >> #define NFC_CMD_SCRAMBLER_DISABLE 0
> >> #define NFC_CMD_SHORTMODE_DISABLE 0
> >> #define NFC_CMD_RB_INT BIT(14)
> >> +#define NFC_CMD_RB_INT_NO_PIN ((0xb << 10) | BIT(18) | BIT(16))
> >>
> >> #define NFC_CMD_GET_SIZE(x) (((x) >> 22) & GENMASK(4, 0))
> >>
> >> @@ -179,6 +180,7 @@ struct meson_nfc {
> >> u32 info_bytes;
> >>
> >> unsigned long assigned_cs;
> >> + bool no_rb_pin;
> >> };
> >>
> >> enum {
> >> @@ -392,7 +394,42 @@ static void meson_nfc_set_data_oob(struct nand_chip *nand,
> >> }
> >> }
> >>
> >> -static int meson_nfc_queue_rb(struct meson_nfc *nfc, int timeout_ms)
> >> +static int meson_nfc_wait_no_rb_pin(struct meson_nfc *nfc, int timeout_ms,
> >> + bool need_cmd_read0)
> >> +{
> >> + u32 cmd, cfg;
> >> +
> >> + meson_nfc_cmd_idle(nfc, nfc->timing.twb);
> >> + meson_nfc_drain_cmd(nfc);
> >> + meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT);
> >> +
> >> + cfg = readl(nfc->reg_base + NFC_REG_CFG);
> >> + cfg |= NFC_RB_IRQ_EN;
> >> + writel(cfg, nfc->reg_base + NFC_REG_CFG);
> >> +
> >> + reinit_completion(&nfc->completion);
> >> + cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_STATUS;
> >> + writel(cmd, nfc->reg_base + NFC_REG_CMD);
> >> +
> >> + /* use the max erase time as the maximum clock for waiting R/B */
> >> + cmd = NFC_CMD_RB | NFC_CMD_RB_INT_NO_PIN | nfc->timing.tbers_max;
> >> + writel(cmd, nfc->reg_base + NFC_REG_CMD);
> >> +
> >> + if (!wait_for_completion_timeout(&nfc->completion,
> >> + msecs_to_jiffies(timeout_ms)))
> >> + return -ETIMEDOUT;
> >> +
> >> + if (need_cmd_read0) {
> >> + cmd = nfc->param.chip_select | NFC_CMD_CLE | NAND_CMD_READ0;
> >> + writel(cmd, nfc->reg_base + NFC_REG_CMD);
> >> + meson_nfc_drain_cmd(nfc);
> >> + meson_nfc_wait_cmd_finish(nfc, CMD_FIFO_EMPTY_TIMEOUT);
> >> + }
> >
> > I forgot about this, you should avoid open coding core helpers, can you
> > please send a followup patch to use nand_status_op() and
> > nand_exit_status_op() ?
>
> A ok, so:
> 1) Sending NAND_CMD_STATUS goes to nand_status_op()
> 2) Sending NAND_CMD_READ0 goes to nand_exit_status_op()
>
> Ok, no problem! I'll prepare and send it on this week!
Exactly. Sorry I had this in mind but I likely forgot to write it
down.
Thanks,
Miquèl
