From mboxrd@z Thu Jan 1 00:00:00 1970 From: Subject: [PATCH v3 01/13] spi: atmel-quadspi: cache MR value to avoid a write access Date: Sat, 2 Feb 2019 04:07:13 +0000 Message-ID: <20190202040653.1217-2-tudor.ambarus@microchip.com> References: <20190202040653.1217-1-tudor.ambarus@microchip.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: devicetree@vger.kernel.org, Tudor.Ambarus@microchip.com, linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org, linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org To: , , , , , , , , Return-path: In-Reply-To: <20190202040653.1217-1-tudor.ambarus@microchip.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-spi.vger.kernel.org From: Tudor Ambarus 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 --- 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) { + qspi_writel(aq, QSPI_MR, QSPI_MR_SMM); + aq->smm = QSPI_MR_SMM; + } mode = find_mode(op); if (mode < 0) -- 2.9.5