From: Pratyush Yadav <p.yadav@ti.com>
To: Patrice CHOTARD <patrice.chotard@foss.st.com>
Cc: Mark Brown <broonie@kernel.org>,
Miquel Raynal <miquel.raynal@bootlin.com>,
Vignesh Raghavendra <vigneshr@ti.com>,
Boris Brezillon <boris.brezillon@collabora.com>,
<linux-mtd@lists.infradead.org>,
Alexandre Torgue <alexandre.torgue@foss.st.com>,
<linux-spi@vger.kernel.org>,
<linux-stm32@st-md-mailman.stormreply.com>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, <christophe.kerello@foss.st.com>
Subject: Re: [PATCH v3 3/3] mtd: spinand: add SPI-NAND MTD resume handler
Date: Fri, 28 May 2021 18:47:00 +0530 [thread overview]
Message-ID: <20210528131658.jtveyvdtxrwj2lgx@ti.com> (raw)
In-Reply-To: <3238725c-d7ff-c000-23d1-f18298e1556f@foss.st.com>
On 28/05/21 02:51PM, Patrice CHOTARD wrote:
> Hi Pratyush
>
> On 5/28/21 2:05 PM, Pratyush Yadav wrote:
> > On 27/05/21 06:12PM, patrice.chotard@foss.st.com wrote:
> >> From: Patrice Chotard <patrice.chotard@foss.st.com>
> >>
> >> After power up, all SPI NAND's blocks are locked. Only read operations
> >> are allowed, write and erase operations are forbidden.
> >> The SPI NAND framework unlocks all the blocks during its initialization.
> >>
> >> During a standby low power, the memory is powered down, losing its
> >> configuration.
> >> During the resume, the QSPI driver state is restored but the SPI NAND
> >> framework does not reconfigured the memory.
> >>
> >> This patch adds SPI-NAND MTD PM handlers for resume ops.
> >> SPI NAND resume op re-initializes SPI NAND flash to its probed state.
> >>
> >> Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
> >> Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
> >> ---
> >> Changes in v3:
> >> - Add spinand_read_cfg() call to repopulate cache
> >>
> >> Changes in v2:
> >> - Add helper spinand_block_unlock().
> >> - Add spinand_ecc_enable() call.
> >> - Remove some dev_err().
> >> - Fix commit's title and message.
> >>
> >> drivers/mtd/nand/spi/core.c | 33 +++++++++++++++++++++++++++++++++
> >> 1 file changed, 33 insertions(+)
> >>
> >> diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
> >> index 1f699ad84f1b..e3fcbcf381c3 100644
> >> --- a/drivers/mtd/nand/spi/core.c
> >> +++ b/drivers/mtd/nand/spi/core.c
> >> @@ -1099,6 +1099,38 @@ static int spinand_block_unlock(struct spinand_device *spinand)
> >> return ret;
> >> }
> >>
> >> +static void spinand_mtd_resume(struct mtd_info *mtd)
> >> +{
> >> + struct spinand_device *spinand = mtd_to_spinand(mtd);
> >> + int ret;
> >> +
> >> + ret = spinand_reset_op(spinand);
> >> + if (ret)
> >> + return;
> >> +
> >> + ret = spinand_read_cfg(spinand);
> >> + if (ret)
> >> + return;
> >> +
> >> + ret = spinand_init_quad_enable(spinand);
> >> + if (ret)
> >> + return;
> >> +
> >> + ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0);
> >> + if (ret)
> >> + return;
> >> +
> >> + ret = spinand_manufacturer_init(spinand);
> >> + if (ret)
> >> + return;
> >> +
> >> + ret = spinand_block_unlock(spinand);
> >> + if (ret)
> >> + return;
> >> +
> >> + spinand_ecc_enable(spinand, false);
> >> +}
> >> +
> >
> > I don't think you quite get what me and Miquel are suggesting.
> >
> > The helper should call all these functions like read_cfg()
> > quad_enable(), etc. So it should look something like:
>
> Yes, this series was sent too quickly on my side, and i misunderstood
> what you suggested, sorry for that.
Ah, I thought this was the v4. I see Miquel clarified already in reply
to this patch.
>
> >
> > int spinand_init_flash()
> > {
> > ret = spinand_read_cfg(spinand);
> > if (ret)
> > return;
> >
>
> The new helper spinand_read_cfg() must not be called in spinand_init_flash()
> but directly in spinand_resume().
> This because spinand_read_cfg() only performs a REG_CFG read without doing the
> memory allocation of spinand->cfg_cache.
>
> In spinand_init(), spinand_init_cfg_cache() must be called as previously as it does spinand->cfg_cache
> memory allocation and call the new helper spinand_read_cfg().
> Then after, spinand_init_flash() can be called.
I think it would be simpler for spinand_init_cfg_cache() to just
allocate the spinand->cfg_cache array and then for spinand_init_flash()
to call spinand_read_cfg().
>
> > ret = spinand_init_quad_enable(spinand);
> > if (ret)
> > return;
> >
> > ret = spinand_upd_cfg(spinand, CFG_OTP_ENABLE, 0);
> > if (ret)
> > return;
> >
> > ret = spinand_manufacturer_init(spinand);
> > if (ret)
> > return;
> >
> > ret = spinand_block_unlock(spinand);
> > if (ret)
> > return;
> >
> > spinand_ecc_enable(spinand, false);
> > }
> >
> > Then spinand_mtd_resume should look something like:
> >
> > int spinand_mtd_resume()
> > {
> > ret = spinand_reset_op(spinand);
> > if (ret)
> > return;
> >
> > return spinand_init_flash();
> > }
> >
> > And spinand_init() should look something like:
> >
> > int spinand_init()
> > {
> > ...
> > spinand->oobbuf = ...
> >
> > spinand_init_flash();
> >
> > spinand_create_dirmaps();
> >
> > ...
>
> As explained just above, spinand_init() will look like :
>
> int spinand_init()
> {
> ...
> spinand->oobbuf = ...
>
> spinand_init_cfg_cache(); => perform cfg cache memory allocation and read the REG_CFG
>
> spinand_init_flash();
>
> spinand_create_dirmaps();
>
> > }
> >
> >
> >> static int spinand_init(struct spinand_device *spinand)
> >> {
> >> struct device *dev = &spinand->spimem->spi->dev;
> >> @@ -1186,6 +1218,7 @@ static int spinand_init(struct spinand_device *spinand)
> >> mtd->_block_isreserved = spinand_mtd_block_isreserved;
> >> mtd->_erase = spinand_mtd_erase;
> >> mtd->_max_bad_blocks = nanddev_mtd_max_bad_blocks;
> >> + mtd->_resume = spinand_mtd_resume;
> >>
> >> if (nand->ecc.engine) {
> >> ret = mtd_ooblayout_count_freebytes(mtd);
> >> --
> >> 2.17.1
> >
>
> Thanks
> Patrice
--
Regards,
Pratyush Yadav
Texas Instruments Inc.
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next prev parent reply other threads:[~2021-05-28 13:42 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-27 16:12 [PATCH v3 0/3] mtd: spinand: add SPI-NAND MTD resume handler patrice.chotard
2021-05-27 16:12 ` [PATCH v3 1/3] mtd: spinand: Add spinand_block_unlock() helper patrice.chotard
2021-05-27 16:12 ` [PATCH v3 2/3] mtd: spinand: add spinand_read_cfg() helper patrice.chotard
2021-05-27 16:12 ` [PATCH v3 3/3] mtd: spinand: add SPI-NAND MTD resume handler patrice.chotard
2021-05-27 16:23 ` Miquel Raynal
2021-05-28 8:22 ` Patrice CHOTARD
2021-05-28 12:05 ` Pratyush Yadav
2021-05-28 12:51 ` Patrice CHOTARD
2021-05-28 13:17 ` Pratyush Yadav [this message]
2021-05-28 14:31 ` Patrice CHOTARD
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