From: Boris Brezillon <bbrezillon@kernel.org>
To: <Tudor.Ambarus@microchip.com>
Cc: mark.rutland@arm.com, devicetree@vger.kernel.org,
alexandre.belloni@bootlin.com, linux-kernel@vger.kernel.org,
Cyrille.Pitchen@microchip.com, robh+dt@kernel.org,
linux-spi@vger.kernel.org, Ludovic.Desroches@microchip.com,
broonie@kernel.org, linux-mtd@lists.infradead.org,
bugalski.piotr@gmail.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 01/13] spi: atmel-quadspi: cache MR value to avoid a write access
Date: Sat, 2 Feb 2019 08:06:50 +0100 [thread overview]
Message-ID: <20190202080650.44becc2d@bbrezillon> (raw)
In-Reply-To: <20190202040653.1217-2-tudor.ambarus@microchip.com>
On Sat, 2 Feb 2019 04:07:13 +0000
<Tudor.Ambarus@microchip.com> wrote:
> From: Tudor Ambarus <tudor.ambarus@microchip.com>
>
> Cache Serial Memory Mode (SMM) value to avoid write access when
> setting the controller in serial memory mode. SMM is set in
> exec_op() and not at probe time, to let room for future regular
> SPI support.
>
> Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
> ---
> v3: update smm value when different. rename mr/smm
> v2: cache MR value instead of moving the write access at probe
>
> drivers/spi/atmel-quadspi.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
> index ddc712410812..645284c6ec9a 100644
> --- a/drivers/spi/atmel-quadspi.c
> +++ b/drivers/spi/atmel-quadspi.c
> @@ -155,6 +155,7 @@ struct atmel_qspi {
> struct clk *clk;
> struct platform_device *pdev;
> u32 pending;
> + u32 smm;
> struct completion cmd_completion;
> };
>
> @@ -238,7 +239,11 @@ static int atmel_qspi_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
> icr = QSPI_ICR_INST(op->cmd.opcode);
> ifr = QSPI_IFR_INSTEN;
>
> - qspi_writel(aq, QSPI_MR, QSPI_MR_SMM);
> + /* Set the QSPI controller in Serial Memory Mode */
> + if (aq->smm != QSPI_MR_SMM) {
Sorry, I think I misunderstood your previous suggestion, I thought the
reg was called SMM. If the reg is called MR and the value you expect in
there is SMM, then the field should be named ->mr as it caches the
whole reg, not only the SMM bit. So it's actually:
if (aq->mr != QSPI_MR_SMM) {
> + qspi_writel(aq, QSPI_MR, QSPI_MR_SMM);
> + aq->smm = QSPI_MR_SMM;
> + }
>
> mode = find_mode(op);
> if (mode < 0)
next prev parent reply other threads:[~2019-02-02 7:06 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-02 4:07 [PATCH v3 00/13] spi: atmel-quadspi: introduce sam9x60 qspi controller Tudor.Ambarus
2019-02-02 4:07 ` [PATCH v3 01/13] spi: atmel-quadspi: cache MR value to avoid a write access Tudor.Ambarus
2019-02-02 7:06 ` Boris Brezillon [this message]
2019-02-02 8:38 ` Tudor.Ambarus
2019-02-02 13:20 ` Boris Brezillon
2019-02-02 4:07 ` [PATCH v3 02/13] spi: atmel-quadspi: order header files inclusion alphabetically Tudor.Ambarus
2019-02-02 4:07 ` [PATCH v3 03/13] spi: atmel-quadspi: drop wrappers for iomem accesses Tudor.Ambarus
2019-02-02 7:11 ` Boris Brezillon
2019-02-02 8:44 ` Tudor.Ambarus
2019-02-02 13:23 ` Boris Brezillon
2019-02-02 4:07 ` [PATCH v3 04/13] spi: atmel-quadspi: fix naming scheme Tudor.Ambarus
2019-02-02 7:12 ` Boris Brezillon
2019-02-02 4:07 ` [PATCH v3 05/13] spi: atmel-quadspi: remove unnecessary cast Tudor.Ambarus
2019-02-02 4:07 ` [PATCH v3 06/13] spi: atmel-quadspi: return appropriate error code Tudor.Ambarus
2019-02-02 4:07 ` [PATCH v3 07/13] spi: atmel-quadspi: switch to SPDX license identifiers Tudor.Ambarus
2019-02-02 4:07 ` [PATCH v3 08/13] spi: atmel-quadspi: drop unused and NOP transfer macros Tudor.Ambarus
2019-02-02 7:13 ` Boris Brezillon
2019-02-02 8:46 ` Tudor.Ambarus
2019-02-02 13:27 ` Boris Brezillon
2019-02-02 4:07 ` [PATCH v3 09/13] dt-bindings: spi: atmel-quadspi: update example to new clock binding Tudor.Ambarus
2019-02-02 4:07 ` [PATCH v3 10/13] dt-bindings: spi: atmel-quadspi: make "pclk" mandatory Tudor.Ambarus
2019-02-02 7:15 ` Boris Brezillon
2019-02-02 8:47 ` Tudor.Ambarus
2019-02-02 4:07 ` [PATCH v3 11/13] spi: atmel-quadspi: add support for named peripheral clock Tudor.Ambarus
2019-02-02 7:16 ` Boris Brezillon
2019-02-02 4:07 ` [PATCH v3 12/13] dt-bindings: spi: atmel-quadspi: QuadSPI driver for Microchip SAM9X60 Tudor.Ambarus
2019-02-02 7:17 ` Boris Brezillon
2019-02-02 4:07 ` [PATCH v3 13/13] spi: atmel-quadspi: add support for sam9x60 qspi controller Tudor.Ambarus
2019-02-02 7:29 ` Boris Brezillon
2019-02-02 8:58 ` Tudor.Ambarus
2019-02-02 13:30 ` Boris Brezillon
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