From: Pratyush Yadav <p.yadav@ti.com>
To: "Ramuthevar,Vadivel MuruganX"
<vadivel.muruganx.ramuthevar@linux.intel.com>
Cc: <vigneshr@ti.com>, <tudor.ambarus@microchip.com>,
<broonie@kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-spi@vger.kernel.org>, <robh+dt@kernel.org>,
<devicetree@vger.kernel.org>, <miquel.raynal@bootlin.com>,
<simon.k.r.goldschmidt@gmail.com>, <dinguyen@kernel.org>,
<richard@nod.at>, <cheol.yong.kim@intel.com>,
<qi-ming.wu@intel.com>
Subject: Re: [PATCH v2 2/6] spi: cadence-quadspi: Disable the DAC for Intel LGM SoC
Date: Wed, 21 Oct 2020 20:47:36 +0530 [thread overview]
Message-ID: <20201021140015.3ldwk4az5nlzhnvr@ti.com> (raw)
In-Reply-To: <20201021025507.51001-3-vadivel.muruganx.ramuthevar@linux.intel.com>
Hi,
On 21/10/20 10:55AM, Ramuthevar,Vadivel MuruganX wrote:
> From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
>
> On Intel Lightning Mountain(LGM) SoCs QSPI controller do not use
> Direct Access Controller(DAC).
>
> This patch adds a quirk to disable the Direct Access Controller
> for data transfer instead it uses indirect data transfer.
>
> Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@linux.intel.com>
> ---
> drivers/spi/spi-cadence-quadspi.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
> index d7b10c46fa70..3d017b484114 100644
> --- a/drivers/spi/spi-cadence-quadspi.c
> +++ b/drivers/spi/spi-cadence-quadspi.c
> @@ -1106,6 +1106,13 @@ static void cqspi_controller_init(struct cqspi_st *cqspi)
> reg |= CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
> writel(reg, cqspi->iobase + CQSPI_REG_CONFIG);
>
> + /* Disable direct access controller */
> + if (!cqspi->use_direct_mode) {
> + reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
> + reg &= ~CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
> + writel(reg, cqspi->iobase + CQSPI_REG_CONFIG);
> + }
> +
Do you really need to disable the DAC controller? cqspi_read() and
cqspi_write() already check for cqspi->use_direct_mode and avoid using
direct mode if it is false. While I don't think it would do any harm I'm
curious what prompted you to do this instead of just setting the quirk
like cdns_qspi does.
Anyway, if you do insist on doing it, it does not make any sense to set
a bit and then unset it immediately after. The datasheet I have says
this bit resets to 1 so the block above the code you added should be
removed.
> cqspi_controller_enable(cqspi, 1);
> }
>
> @@ -1388,6 +1395,10 @@ static const struct cqspi_driver_platdata am654_ospi = {
> .quirks = CQSPI_NEEDS_WR_DELAY,
> };
>
> +static const struct cqspi_driver_platdata intel_lgm_qspi = {
> + .quirks = CQSPI_DISABLE_DAC_MODE,
> +};
> +
> static const struct of_device_id cqspi_dt_ids[] = {
> {
> .compatible = "cdns,qspi-nor",
> @@ -1403,6 +1414,7 @@ static const struct of_device_id cqspi_dt_ids[] = {
> },
> {
> .compatible = "intel,lgm-qspi",
> + .data = &intel_lgm_qspi,
> },
> { /* end of table */ }
> };
--
Regards,
Pratyush Yadav
Texas Instruments India
next prev parent reply other threads:[~2020-10-21 15:18 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-21 2:55 [PATCH v2 0/6] spi: cadence-quadspi: Add QSPI controller support for Intel LGM SoC Ramuthevar,Vadivel MuruganX
2020-10-21 2:55 ` [PATCH v2 1/6] spi: cadence-quadspi: Add QSPI " Ramuthevar,Vadivel MuruganX
2020-10-21 2:55 ` [PATCH v2 2/6] spi: cadence-quadspi: Disable the DAC " Ramuthevar,Vadivel MuruganX
2020-10-21 15:17 ` Pratyush Yadav [this message]
2020-10-22 2:17 ` Ramuthevar, Vadivel MuruganX
2020-10-22 9:01 ` Pratyush Yadav
2020-10-22 9:14 ` Ramuthevar, Vadivel MuruganX
2020-10-21 2:55 ` [PATCH v2 3/6] spi: cadence-quadspi: Add multi-chipselect support " Ramuthevar,Vadivel MuruganX
2020-10-21 14:46 ` Mark Brown
2020-10-21 15:13 ` Pratyush Yadav
2020-10-22 2:07 ` Ramuthevar, Vadivel MuruganX
2020-10-21 2:55 ` [PATCH v2 4/6] spi: Move cadence-quadspi.txt to Documentation/devicetree/bindings/spi Ramuthevar,Vadivel MuruganX
2020-10-21 2:55 ` [PATCH v2 5/6] dt-bindings: spi: Convert cadence-quadspi.txt to cadence-quadspi.yaml Ramuthevar,Vadivel MuruganX
2020-10-21 12:40 ` Mark Brown
2020-10-21 2:55 ` [PATCH v2 6/6] dt-bindings: spi: Add compatible for Intel LGM SoC Ramuthevar,Vadivel MuruganX
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