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!
Thanks, Arseniy
>
> Thanks,
> Miquèl
