Hi Arseniy,
avkrasnov@xxxxxxxxxxxxxx wrote on Tue, 4 Jul 2023 20:32:13 +0300:
> On 04.07.2023 16:07, Arseniy Krasnov wrote:
> >
> >
> > On 04.07.2023 16:12, Miquel Raynal wrote:
> >> 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.
> >
> > Ok, got it!
>
> Hm, seems 'int nand_exit_status_op(struct nand_chip *chip)' is not exported,
> so I can't use it in the Meson module. While 'nand_status_op()' works ok.
> May I can export 'nand_exit_status_op()?'
Yes, in a separate patch please.
>
> Thanks, Arseniy
>
>
> >
> > Thanks, Arseniy
> >
> >>
> >> Thanks,
> >> Miquèl
Thanks,
Miquèl
