linux-kernel - [PATCH v2 2/3] mtd: spi-nor: cadence-quadspi: disable DMA and DAC for Intel LGM

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Date:   Tue, 27 Aug 2019 11:58:26 +0800
From:   "Ramuthevar,Vadivel MuruganX" 
        <vadivel.muruganx.ramuthevar@...ux.intel.com>
To:     linux-mtd@...ts.infradead.org
Cc:     linux-kernel@...r.kernel.org, devicetree@...r.kernel.org,
        dwmw2@...radead.org, computersforpeace@...il.com, richard@....at,
        jwboyer@...il.com, boris.brezillon@...e-electrons.com,
        cyrille.pitchen@...el.com, david.oberhollenzer@...ma-star.at,
        miquel.raynal@...tlin.com, tudor.ambarus@...il.com,
        vigneshr@...com, andriy.shevchenko@...el.com,
        cheol.yong.kim@...el.com, qi-ming.wu@...el.com,
        Ramuthevar Vadivel Murugan 
        <vadivel.muruganx.ramuthevar@...ux.intel.com>
Subject: [PATCH v2 2/3] mtd: spi-nor: cadence-quadspi: disable DMA and DAC for Intel LGM

From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@...ux.intel.com>

on Intel's Lightning Mountain(LGM) SoCs QSPI controller do not use
Direct Memory Access(DMA) and Direct Access Controller(DAC).

This patch introduces to properly disable the DMA and DAC
for data transfer instead it uses indirect data transfer.

Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@...ux.intel.com>
---
 drivers/mtd/spi-nor/Kconfig           |  2 +-
 drivers/mtd/spi-nor/cadence-quadspi.c | 21 ++++++++++++++++++---
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 6de83277ce8b..ba2e372ae514 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -34,7 +34,7 @@ config SPI_ASPEED_SMC
 
 config SPI_CADENCE_QUADSPI
 	tristate "Cadence Quad SPI controller"
-	depends on OF && (ARM || ARM64 || COMPILE_TEST)
+	depends on OF && (ARM || ARM64 || COMPILE_TEST || X86)
 	help
 	  Enable support for the Cadence Quad SPI Flash controller.
 
diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 67f15a1f16fd..69fa13e95110 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -517,12 +517,16 @@ static int cqspi_indirect_read_execute(struct spi_nor *nor, u8 *rxbuf,
 	struct cqspi_st *cqspi = f_pdata->cqspi;
 	void __iomem *reg_base = cqspi->iobase;
 	void __iomem *ahb_base = cqspi->ahb_base;
+	u32 trigger_address = cqspi->trigger_address;
 	unsigned int remaining = n_rx;
 	unsigned int mod_bytes = n_rx % 4;
 	unsigned int bytes_to_read = 0;
 	u8 *rxbuf_end = rxbuf + n_rx;
 	int ret = 0;
 
+	if (!f_pdata->use_direct_mode)
+		writel(trigger_address, reg_base + CQSPI_REG_INDIRECTTRIGGER);
+
 	writel(from_addr, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);
 	writel(remaining, reg_base + CQSPI_REG_INDIRECTRDBYTES);
 
@@ -609,6 +613,14 @@ static int cqspi_write_setup(struct spi_nor *nor)
 	struct cqspi_st *cqspi = f_pdata->cqspi;
 	void __iomem *reg_base = cqspi->iobase;
 
+	/* Disable the DMA and direct access controller */
+	if (!f_pdata->use_direct_mode) {
+		reg = readl(reg_base + CQSPI_REG_CONFIG);
+		reg &= ~CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
+		reg &= ~CQSPI_REG_CONFIG_DMA_MASK;
+		writel(reg, reg_base + CQSPI_REG_CONFIG);
+	}
+
 	/* Set opcode. */
 	reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
 	writel(reg, reg_base + CQSPI_REG_WR_INSTR);
@@ -1171,7 +1183,8 @@ static int cqspi_of_get_pdata(struct platform_device *pdev)
 		return -ENXIO;
 	}
 
-	cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
+	if (!of_device_is_compatible(np, "intel,lgm-qspi"))
+		cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
 
 	return 0;
 }
@@ -1301,7 +1314,8 @@ static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
 		f_pdata->registered = true;
 
 		if (mtd->size <= cqspi->ahb_size) {
-			f_pdata->use_direct_mode = true;
+			f_pdata->use_direct_mode =
+				!(of_device_is_compatible(np, "intel,lgm-qspi"));
 			dev_dbg(nor->dev, "using direct mode for %s\n",
 				mtd->name);
 
@@ -1347,7 +1361,7 @@ static int cqspi_probe(struct platform_device *pdev)
 	}
 
 	/* Obtain QSPI clock. */
-	cqspi->clk = devm_clk_get(dev, NULL);
+	cqspi->clk = devm_clk_get(dev, "qspi");
 	if (IS_ERR(cqspi->clk)) {
 		dev_err(dev, "Cannot claim QSPI clock.\n");
 		return PTR_ERR(cqspi->clk);
@@ -1369,6 +1383,7 @@ static int cqspi_probe(struct platform_device *pdev)
 		return PTR_ERR(cqspi->ahb_base);
 	}
 	cqspi->mmap_phys_base = (dma_addr_t)res_ahb->start;
+	cqspi->trigger_address = res_ahb->start;
 	cqspi->ahb_size = resource_size(res_ahb);
 
 	init_completion(&cqspi->transfer_complete);
-- 
2.11.0