[LINUX PATCH v11 0/3] Add arm pl353 smc memory and nand driver for xilinx zynq soc

[LINUX PATCH v11 0/3] Add arm pl353 smc memory and nand driver for xilinx zynq soc

[Naga Sureshkumar Relli]

The following patches add arm pl353 static memory controller driver and NAND
driver for Xilinx Zynq SoC. The arm pl353 smc supports two interfaces
i.e nand and NOR/SRAM memory interfaces. The current implementation supports
only a single SMC instance and nand specific configuration.

Xilinx Zynq TRM link:
http://www.xilinx.com/support/documentation/user_guides/ug585-Zynq-7000-TRM.pdf

ARM pl353 smc TRM link:
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0380g/DDI0380G_smc_pl350_series_r2p1_trm.pdf

Tested Micron MT29F2G08ABAEAWP (On-die capable) and AMD/Spansion S34ML01G1.
This latest series make use of ->exec_op().

Naga Sureshkumar Relli (3):
  dt-bindings: memory: Add pl353 smc controller devicetree binding
    information
  memory: pl353: Add driver for arm pl353 static memory controller
  mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

 .../bindings/memory-controllers/pl353-smc.txt      |   47 +
 drivers/memory/Kconfig                             |   10 +
 drivers/memory/Makefile                            |    1 +
 drivers/memory/pl353-smc.c                         |  468 +++++++
 drivers/mtd/nand/raw/Kconfig                       |    7 +
 drivers/mtd/nand/raw/Makefile                      |    1 +
 drivers/mtd/nand/raw/pl353_nand.c                  | 1314 ++++++++++++++++++++
 include/linux/pl353-smc.h                          |   30 +
 8 files changed, 1878 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt
 create mode 100644 drivers/memory/pl353-smc.c
 create mode 100644 drivers/mtd/nand/raw/pl353_nand.c
 create mode 100644 include/linux/pl353-smc.h

-- 
2.7.4

[LINUX PATCH v11 1/3] dt-bindings: memory: Add pl353 smc controller devicetree binding information

[Naga Sureshkumar Relli]

Add pl353 static memory controller devicetree binding information.

Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
---
Changes in v11:
 - Changed the subject to dt-bindings
 - Restuctured dt binings to represent peripherals based on ranges property
   as suggested by Boris.
   Now the new bindings uses cs as first address cell value similar to atmel
   EBI/SMC.
 - Added "arm,primecell" as compatible to the existing compatible property
   as per Linus Walleji
 - Changed "aper_clk" to "apb_pclk" as per ARM AMBA peripheral documentation
   as per Linus Walleji.
Changes in v10:
 - Corrected the typos like "should be" to "Must be" and nand to NAND etc..
 - Removed padding to describe size-cells and address-cells
 - Removed timing parameters from DT, and added ->setup_data_interface() hook
   to the driver to read the SDR timings
 - Modified label name from "pl353smcc_0: pl353smcc@e000e000" to
   "smcc: memory-controller@e000e000" as suggested by Miquel
Changes in v9:
 - Addressed below comments given by Randy Dunlap and Miquel Raynal
 - Typos
 - Added extra documentation that explains the HW ECC limitation with SMC
   (Comments given to v8: https://lkml.org/lkml/2018/3/22/23)
Changes in v8:
 - None
Changes in v7:
 - Corrected clocks description
 - prefixed '#' for address and size cells
Changes in v6:
 - None
Changes in v5:
 - Removed timing properties
Changes in v4:
 - none
Changes in v3:
 - none
Changes in v2:
 - modified timing binding info as per onfi timing parameters
 - add suffix nano second as timing unit
 - modified the clock names as per the IP spec
---
 .../bindings/memory-controllers/pl353-smc.txt      | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt

diff --git a/Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt b/Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt
new file mode 100644
index 0000000..d56615f
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory-controllers/pl353-smc.txt
@@ -0,0 +1,47 @@
+Device tree bindings for ARM PL353 static memory controller
+
+PL353 static memory controller supports two kinds of memory
+interfaces.i.e NAND and SRAM/NOR interfaces.
+The actual devices are instantiated from the child nodes of pl353 smc node.
+
+Required properties:
+- compatible		: Should be "arm,pl353-smc-r2p1", "arm,primecell".
+- reg			: Controller registers map and length.
+- clock-names		: List of input clock names - "memclk", "apb_pclk"
+			  (See clock bindings for details).
+- clocks		: Clock phandles (see clock bindings for details).
+- address-cells		: Must be 2.
+- size-cells		: Must be 1.
+
+Child nodes:
+ For NAND the "arm,pl353-nand-r2p1" and for NOR the "cfi-flash" drivers are
+supported as child nodes.
+
+for NAND partition information please refer the below file
+Documentation/devicetree/bindings/mtd/partition.txt
+
+Example:
+	smcc: memory-controller@e000e000
+			compatible = "arm,pl353-smc-r2p1", "arm,primecell";
+			clock-names = "memclk", "apb_pclk";
+			clocks = <&clkc 11>, <&clkc 44>;
+			reg = <0xe000e000 0x1000>;
+			#address-cells = <2>;
+			#size-cells = <1>;
+			ranges = <0x0 0x0 0xe1000000 0x1000000 //Nand CS Region
+				  0x1 0x0 0xe2000000 0x2000000 //SRAM/NOR CS Region
+				  0x2 0x0 0xe4000000 0x2000000>; //SRAM/NOR CS Region
+			nand_0: flash@e1000000 {
+				compatible = "arm,pl353-nand-r2p1"
+				reg = <0 0 0x1000000>;
+				(...)
+			};
+			nor0: flash@e2000000 {
+				compatible = "cfi-flash";
+				reg = <1 0 0x2000000>;
+			};
+			nor1: flash@e4000000 {
+				compatible = "cfi-flash";
+				reg = <2 0 0x2000000>;
+			};
+	};
-- 
2.7.4

[LINUX PATCH v11 2/3] memory: pl353: Add driver for arm pl353 static memory controller

[Naga Sureshkumar Relli]

Add driver for arm pl353 static memory controller. This controller is used in
Xilinx Zynq SoC for interfacing the NAND and NOR/SRAM memory devices.

Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
---
Changes in v11:
 - Added amba device registration and removed platform device, since it
   is an ARM Primecell Peripheral and it should register as an amba device
   as per Linus Walleji.
Changes in v10:
 - Corrected typos in commit message like xilinx to Xilinx
 - Added SoC specific compilation check in Kconfig as below
   "depends on ARCH_ZYNQ"
 - Modified return type from int to bool to the function
   pl353_smc_ecc_is_busy
 - Defined Macros for values in pl353_smc_get_ecc_val and modifed
   the logic to read ecc value from all 4 registers
 - Assinged the timeout value in pl353_smc_init_nand_interface()
   after declaration
 - Added compatibles on another line and aligned the data with them
 - Removed pl353-smc.h from platform-data and moved it to include/linux
Changes in v9:
 - Addressed the comments given by Julia Cartwright to the v8 series.
Changes in v8:
- None
Changes in v7:
- Corrected the kconfig to use tristate selection
- Corrected the GPL licence ident
- Added boundary checks for nand timing parameters
Changes in v6:
- Fixed checkpatch.pl reported warnings
Changes in v5:
- Added pl353_smc_get_clkrate function, made pl353_smc_set_cycles as public
  API
- Removed nand timing parameter initialization and moved it to nand driver
Changes in v4:
- Modified driver to support multiple instances
- Used sleep instaed of busywait for delay
Changes in v3:
- None
Changes in v2:
- Since now the timing parameters are in nano seconds, added logic to convert
  them to the cycles
---
 drivers/memory/Kconfig     |  10 +
 drivers/memory/Makefile    |   1 +
 drivers/memory/pl353-smc.c | 468 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/pl353-smc.h  |  30 +++
 4 files changed, 509 insertions(+)
 create mode 100644 drivers/memory/pl353-smc.c
 create mode 100644 include/linux/pl353-smc.h

diff --git a/drivers/memory/Kconfig b/drivers/memory/Kconfig
index 19a0e83..1a84125 100644
--- a/drivers/memory/Kconfig
+++ b/drivers/memory/Kconfig
@@ -153,6 +153,16 @@ config DA8XX_DDRCTL
 	  Texas Instruments da8xx SoCs. It's used to tweak various memory
 	  controller configuration options.
 
+config PL353_SMC
+	tristate "ARM PL35X Static Memory Controller(SMC) driver"
+	default y
+	depends on ARM
+	depends on ARCH_ZYNQ
+	depends on ARM_AMBA
+	help
+	  This driver is for the ARM PL351/PL353 Static Memory
+	  Controller(SMC) module.
+
 source "drivers/memory/samsung/Kconfig"
 source "drivers/memory/tegra/Kconfig"
 
diff --git a/drivers/memory/Makefile b/drivers/memory/Makefile
index 66f5524..58e794d 100644
--- a/drivers/memory/Makefile
+++ b/drivers/memory/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_TEGRA20_MC)	+= tegra20-mc.o
 obj-$(CONFIG_JZ4780_NEMC)	+= jz4780-nemc.o
 obj-$(CONFIG_MTK_SMI)		+= mtk-smi.o
 obj-$(CONFIG_DA8XX_DDRCTL)	+= da8xx-ddrctl.o
+obj-$(CONFIG_PL353_SMC)		+= pl353-smc.o
 
 obj-$(CONFIG_SAMSUNG_MC)	+= samsung/
 obj-$(CONFIG_TEGRA_MC)		+= tegra/
diff --git a/drivers/memory/pl353-smc.c b/drivers/memory/pl353-smc.c
new file mode 100644
index 0000000..bab5626
--- /dev/null
+++ b/drivers/memory/pl353-smc.c
@@ -0,0 +1,468 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM PL353 SMC driver
+ *
+ * Copyright (C) 2012 Xilinx, Inc
+ * Author: Punnaiah Choudary Kalluri <punnaiah@xilinx.com>
+ * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pl353-smc.h>
+#include <linux/amba/bus.h>
+
+/* Register definitions */
+#define PL353_SMC_MEMC_STATUS_OFFS	0	/* Controller status reg, RO */
+#define PL353_SMC_CFG_CLR_OFFS		0xC	/* Clear config reg, WO */
+#define PL353_SMC_DIRECT_CMD_OFFS	0x10	/* Direct command reg, WO */
+#define PL353_SMC_SET_CYCLES_OFFS	0x14	/* Set cycles register, WO */
+#define PL353_SMC_SET_OPMODE_OFFS	0x18	/* Set opmode register, WO */
+#define PL353_SMC_ECC_STATUS_OFFS	0x400	/* ECC status register */
+#define PL353_SMC_ECC_MEMCFG_OFFS	0x404	/* ECC mem config reg */
+#define PL353_SMC_ECC_MEMCMD1_OFFS	0x408	/* ECC mem cmd1 reg */
+#define PL353_SMC_ECC_MEMCMD2_OFFS	0x40C	/* ECC mem cmd2 reg */
+#define PL353_SMC_ECC_VALUE0_OFFS	0x418	/* ECC value 0 reg */
+
+/* Controller status register specific constants */
+#define PL353_SMC_MEMC_STATUS_RAW_INT_1_SHIFT	6
+
+/* Clear configuration register specific constants */
+#define PL353_SMC_CFG_CLR_INT_CLR_1	0x10
+#define PL353_SMC_CFG_CLR_ECC_INT_DIS_1	0x40
+#define PL353_SMC_CFG_CLR_INT_DIS_1	0x2
+#define PL353_SMC_CFG_CLR_DEFAULT_MASK	(PL353_SMC_CFG_CLR_INT_CLR_1 | \
+					 PL353_SMC_CFG_CLR_ECC_INT_DIS_1 | \
+					 PL353_SMC_CFG_CLR_INT_DIS_1)
+
+/* Set cycles register specific constants */
+#define PL353_SMC_SET_CYCLES_T0_MASK	0xF
+#define PL353_SMC_SET_CYCLES_T0_SHIFT	0
+#define PL353_SMC_SET_CYCLES_T1_MASK	0xF
+#define PL353_SMC_SET_CYCLES_T1_SHIFT	4
+#define PL353_SMC_SET_CYCLES_T2_MASK	0x7
+#define PL353_SMC_SET_CYCLES_T2_SHIFT	8
+#define PL353_SMC_SET_CYCLES_T3_MASK	0x7
+#define PL353_SMC_SET_CYCLES_T3_SHIFT	11
+#define PL353_SMC_SET_CYCLES_T4_MASK	0x7
+#define PL353_SMC_SET_CYCLES_T4_SHIFT	14
+#define PL353_SMC_SET_CYCLES_T5_MASK	0x7
+#define PL353_SMC_SET_CYCLES_T5_SHIFT	17
+#define PL353_SMC_SET_CYCLES_T6_MASK	0xF
+#define PL353_SMC_SET_CYCLES_T6_SHIFT	20
+
+/* ECC status register specific constants */
+#define PL353_SMC_ECC_STATUS_BUSY	BIT(6)
+#define PL353_SMC_ECC_REG_SIZE_OFFS	4
+
+/* ECC memory config register specific constants */
+#define PL353_SMC_ECC_MEMCFG_MODE_MASK	0xC
+#define PL353_SMC_ECC_MEMCFG_MODE_SHIFT	2
+#define PL353_SMC_ECC_MEMCFG_PGSIZE_MASK	0xC
+
+#define PL353_SMC_DC_UPT_NAND_REGS	((4 << 23) |	/* CS: NAND chip */ \
+				 (2 << 21))	/* UpdateRegs operation */
+
+#define PL353_NAND_ECC_CMD1	((0x80)       |	/* Write command */ \
+				 (0 << 8)     |	/* Read command */ \
+				 (0x30 << 16) |	/* Read End command */ \
+				 (1 << 24))	/* Read End command calid */
+
+#define PL353_NAND_ECC_CMD2	((0x85)	      |	/* Write col change cmd */ \
+				 (5 << 8)     |	/* Read col change cmd */ \
+				 (0xE0 << 16) |	/* Read col change end cmd */ \
+				 (1 << 24)) /* Read col change end cmd valid */
+#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
+/**
+ * struct pl353_smc_data - Private smc driver structure
+ * @memclk:		Pointer to the peripheral clock
+ * @aclk:		Pointer to the APER clock
+ */
+struct pl353_smc_data {
+	struct clk		*memclk;
+	struct clk		*aclk;
+};
+
+/* SMC virtual register base */
+static void __iomem *pl353_smc_base;
+
+/**
+ * pl353_smc_set_buswidth - Set memory buswidth
+ * @bw:	Memory buswidth (8 | 16)
+ * Return: 0 on success or negative errno.
+ */
+int pl353_smc_set_buswidth(unsigned int bw)
+{
+	if (bw != PL353_SMC_MEM_WIDTH_8  && bw != PL353_SMC_MEM_WIDTH_16)
+		return -EINVAL;
+
+	writel(bw, pl353_smc_base + PL353_SMC_SET_OPMODE_OFFS);
+	writel(PL353_SMC_DC_UPT_NAND_REGS, pl353_smc_base +
+	       PL353_SMC_DIRECT_CMD_OFFS);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pl353_smc_set_buswidth);
+
+/**
+ * pl353_smc_set_cycles - Set memory timing parameters
+ * @timings: NAND controller timing parameters
+ *
+ * Sets NAND chip specific timing parameters.
+ */
+void pl353_smc_set_cycles(u32 timings[])
+{
+	/*
+	 * Set write pulse timing. This one is easy to extract:
+	 *
+	 * NWE_PULSE = tWP
+	 */
+	timings[0] &= PL353_SMC_SET_CYCLES_T0_MASK;
+	timings[1] = (timings[1] & PL353_SMC_SET_CYCLES_T1_MASK) <<
+			PL353_SMC_SET_CYCLES_T1_SHIFT;
+	timings[2] = (timings[2]  & PL353_SMC_SET_CYCLES_T2_MASK) <<
+			PL353_SMC_SET_CYCLES_T2_SHIFT;
+	timings[3] = (timings[3]  & PL353_SMC_SET_CYCLES_T3_MASK) <<
+			PL353_SMC_SET_CYCLES_T3_SHIFT;
+	timings[4] = (timings[4] & PL353_SMC_SET_CYCLES_T4_MASK) <<
+			PL353_SMC_SET_CYCLES_T4_SHIFT;
+	timings[5]  = (timings[5]  & PL353_SMC_SET_CYCLES_T5_MASK) <<
+			PL353_SMC_SET_CYCLES_T5_SHIFT;
+	timings[6]  = (timings[6]  & PL353_SMC_SET_CYCLES_T6_MASK) <<
+			PL353_SMC_SET_CYCLES_T6_SHIFT;
+	timings[0] |= timings[1] | timings[2] | timings[3] |
+			timings[4] | timings[5] | timings[6];
+
+	writel(timings[0], pl353_smc_base + PL353_SMC_SET_CYCLES_OFFS);
+	writel(PL353_SMC_DC_UPT_NAND_REGS, pl353_smc_base +
+	       PL353_SMC_DIRECT_CMD_OFFS);
+}
+EXPORT_SYMBOL_GPL(pl353_smc_set_cycles);
+
+/**
+ * pl353_smc_ecc_is_busy - Read ecc busy flag
+ * Return: the ecc_status bit from the ecc_status register. 1 = busy, 0 = idle
+ */
+bool pl353_smc_ecc_is_busy(void)
+{
+	return ((readl(pl353_smc_base + PL353_SMC_ECC_STATUS_OFFS) &
+		  PL353_SMC_ECC_STATUS_BUSY) == PL353_SMC_ECC_STATUS_BUSY);
+}
+EXPORT_SYMBOL_GPL(pl353_smc_ecc_is_busy);
+
+/**
+ * pl353_smc_get_ecc_val - Read ecc_valueN registers
+ * @ecc_reg:	Index of the ecc_value reg (0..3)
+ * Return: the content of the requested ecc_value register.
+ *
+ * There are four valid ecc_value registers. The argument is truncated to stay
+ * within this valid boundary.
+ */
+u32 pl353_smc_get_ecc_val(int ecc_reg)
+{
+	u32 addr, reg;
+
+	addr = PL353_SMC_ECC_VALUE0_OFFS +
+		(ecc_reg * PL353_SMC_ECC_REG_SIZE_OFFS);
+	reg = readl(pl353_smc_base + addr);
+
+	return reg;
+}
+EXPORT_SYMBOL_GPL(pl353_smc_get_ecc_val);
+
+/**
+ * pl353_smc_get_nand_int_status_raw - Get NAND interrupt status bit
+ * Return: the raw_int_status1 bit from the memc_status register
+ */
+int pl353_smc_get_nand_int_status_raw(void)
+{
+	u32 reg;
+
+	reg = readl(pl353_smc_base + PL353_SMC_MEMC_STATUS_OFFS);
+	reg >>= PL353_SMC_MEMC_STATUS_RAW_INT_1_SHIFT;
+	reg &= 1;
+
+	return reg;
+}
+EXPORT_SYMBOL_GPL(pl353_smc_get_nand_int_status_raw);
+
+/**
+ * pl353_smc_clr_nand_int - Clear NAND interrupt
+ */
+void pl353_smc_clr_nand_int(void)
+{
+	writel(PL353_SMC_CFG_CLR_INT_CLR_1,
+	       pl353_smc_base + PL353_SMC_CFG_CLR_OFFS);
+}
+EXPORT_SYMBOL_GPL(pl353_smc_clr_nand_int);
+
+/**
+ * pl353_smc_set_ecc_mode - Set SMC ECC mode
+ * @mode:	ECC mode (BYPASS, APB, MEM)
+ * Return: 0 on success or negative errno.
+ */
+int pl353_smc_set_ecc_mode(enum pl353_smc_ecc_mode mode)
+{
+	u32 reg;
+	int ret = 0;
+
+	switch (mode) {
+	case PL353_SMC_ECCMODE_BYPASS:
+	case PL353_SMC_ECCMODE_APB:
+	case PL353_SMC_ECCMODE_MEM:
+
+		reg = readl(pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
+		reg &= ~PL353_SMC_ECC_MEMCFG_MODE_MASK;
+		reg |= mode << PL353_SMC_ECC_MEMCFG_MODE_SHIFT;
+		writel(reg, pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
+
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pl353_smc_set_ecc_mode);
+
+/**
+ * pl353_smc_set_ecc_pg_size - Set SMC ECC page size
+ * @pg_sz:	ECC page size
+ * Return: 0 on success or negative errno.
+ */
+int pl353_smc_set_ecc_pg_size(unsigned int pg_sz)
+{
+	u32 reg, sz;
+
+	switch (pg_sz) {
+	case 0:
+		sz = 0;
+		break;
+	case SZ_512:
+		sz = 1;
+		break;
+	case SZ_1K:
+		sz = 2;
+		break;
+	case SZ_2K:
+		sz = 3;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	reg = readl(pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
+	reg &= ~PL353_SMC_ECC_MEMCFG_PGSIZE_MASK;
+	reg |= sz;
+	writel(reg, pl353_smc_base + PL353_SMC_ECC_MEMCFG_OFFS);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pl353_smc_set_ecc_pg_size);
+
+static int __maybe_unused pl353_smc_suspend(struct device *dev)
+{
+	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
+
+	clk_disable(pl353_smc->memclk);
+	clk_disable(pl353_smc->aclk);
+
+	return 0;
+}
+
+static int __maybe_unused pl353_smc_resume(struct device *dev)
+{
+	int ret;
+	struct pl353_smc_data *pl353_smc = dev_get_drvdata(dev);
+
+	ret = clk_enable(pl353_smc->aclk);
+	if (ret) {
+		dev_err(dev, "Cannot enable axi domain clock.\n");
+		return ret;
+	}
+
+	ret = clk_enable(pl353_smc->memclk);
+	if (ret) {
+		dev_err(dev, "Cannot enable memory clock.\n");
+		clk_disable(pl353_smc->aclk);
+		return ret;
+	}
+
+	return ret;
+}
+static struct amba_driver pl353_smc_driver;
+static SIMPLE_DEV_PM_OPS(pl353_smc_dev_pm_ops, pl353_smc_suspend,
+			 pl353_smc_resume);
+
+/**
+ * pl353_smc_init_nand_interface - Initialize the NAND interface
+ * @adev:	Pointer to the amba_device struct
+ * @nand_node:	Pointer to the pl353_nand device_node struct
+ */
+void pl353_smc_init_nand_interface(struct amba_device *adev,
+					struct device_node *nand_node)
+{
+	unsigned long timeout;
+
+	pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_8);
+	writel(PL353_SMC_CFG_CLR_INT_CLR_1,
+	       pl353_smc_base + PL353_SMC_CFG_CLR_OFFS);
+	writel(PL353_SMC_DC_UPT_NAND_REGS, pl353_smc_base +
+	       PL353_SMC_DIRECT_CMD_OFFS);
+
+	timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
+	/* Wait till the ECC operation is complete */
+	do {
+		if (pl353_smc_ecc_is_busy())
+			cpu_relax();
+		else
+			break;
+	} while (!time_after_eq(jiffies, timeout));
+
+	if (time_after_eq(jiffies, timeout))
+		return;
+
+	writel(PL353_NAND_ECC_CMD1,
+	       pl353_smc_base + PL353_SMC_ECC_MEMCMD1_OFFS);
+	writel(PL353_NAND_ECC_CMD2,
+	       pl353_smc_base + PL353_SMC_ECC_MEMCMD2_OFFS);
+}
+
+static const struct of_device_id pl353_smc_supported_children[] = {
+	{
+		.compatible = "cfi-flash"
+	},
+	{
+		.compatible = "arm,pl353-nand-r2p1",
+		.data = pl353_smc_init_nand_interface
+	},
+	{}
+};
+
+static int pl353_smc_probe(struct amba_device *adev, const struct amba_id *id)
+{
+	struct pl353_smc_data *pl353_smc;
+	struct device_node *child;
+	struct resource *res;
+	int err;
+	struct device_node *of_node = adev->dev.of_node;
+	void (*init)(struct amba_device *adev,
+		     struct device_node *nand_node);
+	const struct of_device_id *match = NULL;
+
+	pl353_smc = devm_kzalloc(&adev->dev, sizeof(*pl353_smc), GFP_KERNEL);
+	if (!pl353_smc)
+		return -ENOMEM;
+
+	/* Get the NAND controller virtual address */
+	res = &adev->res;
+	pl353_smc_base = devm_ioremap_resource(&adev->dev, res);
+	if (IS_ERR(pl353_smc_base))
+		return PTR_ERR(pl353_smc_base);
+
+	pl353_smc->aclk = devm_clk_get(&adev->dev, "apb_pclk");
+	if (IS_ERR(pl353_smc->aclk)) {
+		dev_err(&adev->dev, "aclk clock not found.\n");
+		return PTR_ERR(pl353_smc->aclk);
+	}
+
+	pl353_smc->memclk = devm_clk_get(&adev->dev, "memclk");
+	if (IS_ERR(pl353_smc->memclk)) {
+		dev_err(&adev->dev, "memclk clock not found.\n");
+		return PTR_ERR(pl353_smc->memclk);
+	}
+
+	err = clk_prepare_enable(pl353_smc->aclk);
+	if (err) {
+		dev_err(&adev->dev, "Unable to enable AXI clock.\n");
+		return err;
+	}
+
+	err = clk_prepare_enable(pl353_smc->memclk);
+	if (err) {
+		dev_err(&adev->dev, "Unable to enable memory clock.\n");
+		goto out_clk_dis_aper;
+	}
+
+	amba_set_drvdata(adev, pl353_smc);
+
+	/* clear interrupts */
+	writel(PL353_SMC_CFG_CLR_DEFAULT_MASK,
+	       pl353_smc_base + PL353_SMC_CFG_CLR_OFFS);
+
+	/* Find compatible children. Only a single child is supported */
+	for_each_available_child_of_node(of_node, child) {
+		match = of_match_node(pl353_smc_supported_children, child);
+		if (!match) {
+			dev_warn(&adev->dev, "unsupported child node\n");
+			continue;
+		}
+		break;
+	}
+	if (!match) {
+		dev_err(&adev->dev, "no matching children\n");
+		goto out_clk_disable;
+	}
+
+	init = match->data;
+	if (init)
+		init(adev, child);
+	of_platform_device_create(child, NULL, &adev->dev);
+
+	return 0;
+
+out_clk_disable:
+	clk_disable_unprepare(pl353_smc->memclk);
+out_clk_dis_aper:
+	clk_disable_unprepare(pl353_smc->aclk);
+
+	return err;
+}
+
+static int pl353_smc_remove(struct amba_device *adev)
+{
+	struct pl353_smc_data *pl353_smc = amba_get_drvdata(adev);
+
+	clk_disable_unprepare(pl353_smc->memclk);
+	clk_disable_unprepare(pl353_smc->aclk);
+
+	return 0;
+}
+
+/* Match table for device tree binding */
+static const struct of_device_id pl353_smc_of_match[] = {
+	{ .compatible = "arm,pl353-smc-r2p1" },
+	{ },
+};
+
+static const struct amba_id pl353_ids[] = {
+	{
+	.id = 0x00041353,
+	.mask = 0x000fffff,
+	},
+	{ 0, 0 },
+};
+MODULE_DEVICE_TABLE(amba, pl353_ids);
+
+static struct amba_driver pl353_smc_driver = {
+	.drv = {
+		.owner = THIS_MODULE,
+		.name = "pl353-smc",
+		.pm = &pl353_smc_dev_pm_ops,
+	},
+	.id_table = pl353_ids,
+	.probe		= pl353_smc_probe,
+	.remove		= pl353_smc_remove,
+};
+
+module_amba_driver(pl353_smc_driver);
+
+MODULE_AUTHOR("Xilinx, Inc.");
+MODULE_DESCRIPTION("ARM PL353 SMC Driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/pl353-smc.h b/include/linux/pl353-smc.h
new file mode 100644
index 0000000..2939d49
--- /dev/null
+++ b/include/linux/pl353-smc.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ARM PL353 SMC Driver Header
+ *
+ * Copyright (C) 2017 Xilinx, Inc
+ */
+
+#ifndef __LINUX_MEMORY_PL353_SMC_H
+#define __LINUX_MEMORY_PL353_SMC_H
+
+enum pl353_smc_ecc_mode {
+	PL353_SMC_ECCMODE_BYPASS = 0,
+	PL353_SMC_ECCMODE_APB = 1,
+	PL353_SMC_ECCMODE_MEM = 2
+};
+
+enum pl353_smc_mem_width {
+	PL353_SMC_MEM_WIDTH_8 = 0,
+	PL353_SMC_MEM_WIDTH_16 = 1
+};
+
+u32 pl353_smc_get_ecc_val(int ecc_reg);
+bool pl353_smc_ecc_is_busy(void);
+int pl353_smc_get_nand_int_status_raw(void);
+void pl353_smc_clr_nand_int(void);
+int pl353_smc_set_ecc_mode(enum pl353_smc_ecc_mode mode);
+int pl353_smc_set_ecc_pg_size(unsigned int pg_sz);
+int pl353_smc_set_buswidth(unsigned int bw);
+void pl353_smc_set_cycles(u32 timings[]);
+#endif
-- 
2.7.4

[LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

[Naga Sureshkumar Relli]

Add driver for arm pl353 static memory controller nand interface with HW ECC
support. This controller is used in Xilinx Zynq SoC for interfacing the NAND
flash memory.

Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
---
Changes in v11:
 - Removed Documentation patch and added the required info in driver as
   per Boris comments.
 - Removed unwanted variables from pl353_nand_info as per Miquel comments
 - Removed IO_ADDR_R/W.
 - Replaced onhot() with hweight32()
 - Defined macros for static values in function pl353_nand_correct_data()
 - Removed all unnecessary delays
 - Used nand_wait_ready() where ever is required
 - Modifed the pl353_setup_data_interface() logic as per Miquel comments.
 - Taken array instead of 7 values in pl353_setup_data_interface() and pass
   it to smc driver.
 - Added check to collect the return value of mtd_device_register().
Changes in 10:
 - Typos correction like nand to NAND and soc to SOC etc..
 - Defined macros for the values in pl353_nand_calculate_hwecc()
 - Modifed ecc_status from int to char in pl353_nand_calculate_hwecc()
 - Changed the return type form int to bool to the function
   onehot()
 - Removed udelay(1000) in pl353_cmd_function, as it is not required
 - Dropped ecc->hwctl = NULL in pl353_ecc_init()
 - Added an error message in pl353_ecc_init(), when there is no matching
   oobsize
 - Changed the variable from xnand to xnfc
 - Added logic to get mtd->name from DT, if it is specified in DT
Changes in v9:
 - Addressed the below comments given by Miquel
 - instead of using pl353_nand_write32, use directly writel_relaxed
 - Fixed check patch warnings
 - Renamed write_buf/read_buf to write_data_op/read_data_op
 - use BIT macro instead of 1 << nr
 - Use NAND_ROW_ADDR_3 flag
 - Use nand_wait_ready()
 - Removed swecc functions
 - Use address cycles as per size, instead of reading it from Parameter page
 - Instead of writing too many patterns, use optional property
Changes in v8:
 - Added exec_op() implementation
 - Fixed the below v7 review comments
 - removed mtd_info from pl353_nand_info struct
 - Corrected ecc layout offsets
 - Added on-die ecc support
Changes in v7:
 - Currently not implemented the memclk rate adjustments. I will
   look into this later and once the basic driver is accepted.
 - Fixed GPL licence ident
Changes in v6:
 - Fixed the checkpatch.pl reported warnings
 - Using the address cycles information from the onfi param page
   earlier it is hardcoded to 5 in driver
Changes in v5:
 - Configure the nand timing parameters as per the onfi spec Changes in v4:
 - Updated the driver to sync with pl353_smc driver APIs
Changes in v3:
 - implemented the proper error codes
 - further breakdown this patch to multiple sets
 - added the controller and driver details to Documentation section
 - updated the licenece to GPLv2
 - reorganized the pl353_nand_ecc_init function
Changes in v2:
 - use "depends on" rather than "select" option in kconfig
 - remove unused variable parts
---
 drivers/mtd/nand/raw/Kconfig      |    7 +
 drivers/mtd/nand/raw/Makefile     |    1 +
 drivers/mtd/nand/raw/pl353_nand.c | 1314 +++++++++++++++++++++++++++++++++++++
 3 files changed, 1322 insertions(+)
 create mode 100644 drivers/mtd/nand/raw/pl353_nand.c

diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
index 6871ff0..1c5d528 100644
--- a/drivers/mtd/nand/raw/Kconfig
+++ b/drivers/mtd/nand/raw/Kconfig
@@ -530,4 +530,11 @@ config MTD_NAND_MTK
 	  Enables support for NAND controller on MTK SoCs.
 	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
 
+config MTD_NAND_PL353
+	tristate "ARM Pl353 NAND flash driver"
+	depends on MTD_NAND && ARM
+	depends on PL353_SMC
+	help
+	  Enables support for PrimeCell Static Memory Controller PL353.
+
 endif # MTD_NAND
diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
index 165b7ef..1c702e1 100644
--- a/drivers/mtd/nand/raw/Makefile
+++ b/drivers/mtd/nand/raw/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
 obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
 obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
 obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
+obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o
 
 nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
 nand-objs += nand_amd.o
diff --git a/drivers/mtd/nand/raw/pl353_nand.c b/drivers/mtd/nand/raw/pl353_nand.c
new file mode 100644
index 0000000..3fa9ba07
--- /dev/null
+++ b/drivers/mtd/nand/raw/pl353_nand.c
@@ -0,0 +1,1314 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM PL353 NAND flash controller driver
+ *
+ * Copyright (C) 2017 Xilinx, Inc
+ * Author: Punnaiah chowdary kalluri <punnaiah@xilinx.com>
+ * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
+ *
+ */
+
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/rawnand.h>
+#include <linux/mtd/nand_ecc.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/pl353-smc.h>
+#include <linux/clk.h>
+
+#define PL353_NAND_DRIVER_NAME "pl353-nand"
+
+/* NAND flash driver defines */
+#define PL353_NAND_CMD_PHASE	1	/* End command valid in command phase */
+#define PL353_NAND_DATA_PHASE	2	/* End command valid in data phase */
+#define PL353_NAND_ECC_SIZE	512	/* Size of data for ECC operation */
+
+/* Flash memory controller operating parameters */
+
+#define PL353_NAND_ECC_CONFIG	(BIT(4)  |	/* ECC read at end of page */ \
+				 (0 << 5))	/* No Jumping */
+
+/* AXI Address definitions */
+#define START_CMD_SHIFT		3
+#define END_CMD_SHIFT		11
+#define END_CMD_VALID_SHIFT	20
+#define ADDR_CYCLES_SHIFT	21
+#define CLEAR_CS_SHIFT		21
+#define ECC_LAST_SHIFT		10
+#define COMMAND_PHASE		(0 << 19)
+#define DATA_PHASE		BIT(19)
+
+#define PL353_NAND_ECC_LAST	BIT(ECC_LAST_SHIFT)	/* Set ECC_Last */
+#define PL353_NAND_CLEAR_CS	BIT(CLEAR_CS_SHIFT)	/* Clear chip select */
+
+#define ONDIE_ECC_FEATURE_ADDR	0x90
+#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
+#define PL353_NAND_DEV_BUSY_TIMEOUT	(1 * HZ)
+#define PL353_NAND_LAST_TRANSFER_LENGTH	4
+#define PL353_NAND_ECC_VALID_SHIFT	24
+#define PL353_NAND_ECC_VALID_MASK	0x40
+#define PL353_ECC_BITS_BYTEOFF_MASK	0x1FF
+#define PL353_ECC_BITS_BITOFF_MASK	0x7
+#define PL353_ECC_BIT_MASK		0xFFF
+#define PL353_TREA_MAX_VALUE		1
+
+struct pl353_nfc_op {
+	u32 cmnds[4];
+	u32 thirdrow;
+	u32 type;
+	u32 end_cmd;
+	u32 addrs;
+	u32 len;
+	u32 naddrs;
+	u32 addr5;
+	u32 addr6;
+	unsigned int data_instr_idx;
+	unsigned int rdy_timeout_ms;
+	unsigned int rdy_delay_ns;
+	unsigned int cle_ale_delay_ns;
+	const struct nand_op_instr *data_instr;
+};
+
+/**
+ * struct pl353_nand_info - Defines the NAND flash driver instance
+ * @chip:		NAND chip information structure
+ * @dev:		Parent device (used to print error messages)
+ * @nand_base:		Virtual address of the NAND flash device
+ * @nandaddr:		Virtual address of the NAND flash device for
+ *			data read/writes
+ * @addr_cycles:	Address cycles
+ * @mclk:		Memory controller clock
+ */
+struct pl353_nand_info {
+	struct nand_chip chip;
+	struct device *dev;
+	void __iomem *nand_base;
+	void __iomem *nandaddr;
+	u8 addr_cycles;
+	struct clk *mclk;
+};
+
+static int pl353_ecc_ooblayout16_ecc(struct mtd_info *mtd, int section,
+				     struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (section >= chip->ecc.steps)
+		return -ERANGE;
+
+	oobregion->offset = (section * chip->ecc.bytes);
+	oobregion->length = chip->ecc.bytes;
+
+	return 0;
+}
+
+static int pl353_ecc_ooblayout16_free(struct mtd_info *mtd, int section,
+				      struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (section >= chip->ecc.steps)
+		return -ERANGE;
+
+	oobregion->offset = (section * chip->ecc.bytes) + 8;
+	oobregion->length = 8;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops pl353_ecc_ooblayout16_ops = {
+	.ecc = pl353_ecc_ooblayout16_ecc,
+	.free = pl353_ecc_ooblayout16_free,
+};
+
+static int pl353_ecc_ooblayout64_ecc(struct mtd_info *mtd, int section,
+				     struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (section >= chip->ecc.steps)
+		return -ERANGE;
+
+	oobregion->offset = (section * chip->ecc.bytes) + 52;
+	oobregion->length = chip->ecc.bytes;
+
+	return 0;
+}
+
+static int pl353_ecc_ooblayout64_free(struct mtd_info *mtd, int section,
+				      struct mtd_oob_region *oobregion)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+
+	if (section)
+		return -ERANGE;
+
+	if (section >= chip->ecc.steps)
+		return -ERANGE;
+
+	oobregion->offset = (section * chip->ecc.bytes) + 2;
+	oobregion->length = 50;
+
+	return 0;
+}
+
+static const struct mtd_ooblayout_ops pl353_ecc_ooblayout64_ops = {
+	.ecc = pl353_ecc_ooblayout64_ecc,
+	.free = pl353_ecc_ooblayout64_free,
+};
+
+/* Generic flash bbt decriptors */
+static u8 bbt_pattern[] = { 'B', 'b', 't', '0' };
+static u8 mirror_pattern[] = { '1', 't', 'b', 'B' };
+
+static struct nand_bbt_descr bbt_main_descr = {
+	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+	.offs = 4,
+	.len = 4,
+	.veroffs = 20,
+	.maxblocks = 4,
+	.pattern = bbt_pattern
+};
+
+static struct nand_bbt_descr bbt_mirror_descr = {
+	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
+		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+	.offs = 4,
+	.len = 4,
+	.veroffs = 20,
+	.maxblocks = 4,
+	.pattern = mirror_pattern
+};
+
+/**
+ * pl353_nand_read_data_op - read chip data into buffer
+ * @chip:	Pointer to the NAND chip info structure
+ * @in:		Pointer to the buffer to store read data
+ * @len:	Number of bytes to read
+ * Return:	Always return zero
+ */
+static int pl353_nand_read_data_op(struct nand_chip *chip,
+				   u8 *in,
+				   unsigned int len)
+{
+	int i;
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+
+	if (IS_ALIGNED((uint32_t)in, sizeof(uint32_t)) &&
+	    IS_ALIGNED(len, sizeof(uint32_t))) {
+		u32 *ptr = (u32 *)in;
+
+		len /= 4;
+		for (i = 0; i < len; i++)
+			ptr[i] = readl(xnfc->nandaddr);
+	} else {
+		for (i = 0; i < len; i++)
+			in[i] = readb(xnfc->nandaddr);
+	}
+
+	return 0;
+}
+
+/**
+ * pl353_nand_write_buf - write buffer to chip
+ * @mtd:	Pointer to the mtd info structure
+ * @buf:	Pointer to the buffer to store write data
+ * @len:	Number of bytes to write
+ */
+static void pl353_nand_write_data_op(struct mtd_info *mtd, const u8 *buf,
+				     int len)
+{
+	int i;
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+
+	if (IS_ALIGNED((uint32_t)buf, sizeof(uint32_t)) &&
+	    IS_ALIGNED(len, sizeof(uint32_t))) {
+		u32 *ptr = (u32 *)buf;
+
+		len /= 4;
+		for (i = 0; i < len; i++)
+			writel(ptr[i], xnfc->nandaddr);
+	} else {
+		for (i = 0; i < len; i++)
+			writeb(buf[i], xnfc->nandaddr);
+	}
+}
+
+/**
+ * pl353_nand_calculate_hwecc - Calculate Hardware ECC
+ * @mtd:	Pointer to the mtd_info structure
+ * @data:	Pointer to the page data
+ * @ecc:	Pointer to the ECC buffer where ECC data needs to be stored
+ *
+ * This function retrieves the Hardware ECC data from the controller and returns
+ * ECC data back to the MTD subsystem.
+ * It operates on a number of 512 byte blocks of NAND memory and can be
+ * programmed to store the ECC codes after the data in memory. For writes,
+ * the ECC is written to the spare area of the page. For reads, the result of
+ * a block ECC check are made available to the device driver.
+ *
+ * ------------------------------------------------------------------------
+ * |               n * 512 blocks                  | extra  | ecc    |     |
+ * |                                               | block  | codes  |     |
+ * ------------------------------------------------------------------------
+ *
+ * The ECC calculation uses a simple Hamming code, using 1-bit correction 2-bit
+ * detection. It starts when a valid read or write command with a 512 byte
+ * aligned address is detected on the memory interface.
+ *
+ * Return:	0 on success or error value on failure
+ */
+static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
+				      const u8 *data, u8 *ecc)
+{
+	u32 ecc_value;
+	u8 ecc_reg, ecc_byte, ecc_status;
+	unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
+
+	/* Wait till the ECC operation is complete or timeout */
+	do {
+		if (pl353_smc_ecc_is_busy())
+			cpu_relax();
+		else
+			break;
+	} while (!time_after_eq(jiffies, timeout));
+
+	if (time_after_eq(jiffies, timeout)) {
+		pr_err("%s timed out\n", __func__);
+		return -ETIMEDOUT;
+	}
+
+	for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
+		/* Read ECC value for each block */
+		ecc_value = pl353_smc_get_ecc_val(ecc_reg);
+		ecc_status = (ecc_value >> PL353_NAND_ECC_VALID_SHIFT);
+		/* ECC value valid */
+		if (ecc_status & PL353_NAND_ECC_VALID_MASK) {
+			for (ecc_byte = 0; ecc_byte < 3; ecc_byte++) {
+				/* Copy ECC bytes to MTD buffer */
+				*ecc = ~ecc_value & 0xFF;
+				ecc_value = ecc_value >> 8;
+				ecc++;
+			}
+		} else {
+			pr_warn("%s status failed\n", __func__);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * pl353_nand_correct_data - ECC correction function
+ * @mtd:	Pointer to the mtd_info structure
+ * @buf:	Pointer to the page data
+ * @read_ecc:	Pointer to the ECC value read from spare data area
+ * @calc_ecc:	Pointer to the calculated ECC value
+ *
+ * This function corrects the ECC single bit errors & detects 2-bit errors.
+ *
+ * Return:	0 if no ECC errors found
+ *		1 if single bit error found and corrected.
+ *		-1 if multiple uncorrectable ECC errors found.
+ */
+static int pl353_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
+				   unsigned char *read_ecc,
+				   unsigned char *calc_ecc)
+{
+	unsigned char bit_addr;
+	unsigned int byte_addr;
+	unsigned short ecc_odd, ecc_even, read_ecc_lower, read_ecc_upper;
+	unsigned short calc_ecc_lower, calc_ecc_upper;
+
+	read_ecc_lower = (read_ecc[0] | (read_ecc[1] << 8)) &
+			  PL353_ECC_BIT_MASK;
+	read_ecc_upper = ((read_ecc[1] >> 4) | (read_ecc[2] << 4)) &
+			  PL353_ECC_BIT_MASK;
+
+	calc_ecc_lower = (calc_ecc[0] | (calc_ecc[1] << 8)) &
+			  PL353_ECC_BIT_MASK;
+	calc_ecc_upper = ((calc_ecc[1] >> 4) | (calc_ecc[2] << 4)) &
+			  PL353_ECC_BIT_MASK;
+
+	ecc_odd = read_ecc_lower ^ calc_ecc_lower;
+	ecc_even = read_ecc_upper ^ calc_ecc_upper;
+
+	/* no error */
+	if (!ecc_odd && !ecc_even)
+		return 0;
+
+	if (ecc_odd == (~ecc_even & PL353_ECC_BIT_MASK)) {
+		/* bits [11:3] of error code is byte offset */
+		byte_addr = (ecc_odd >> 3) & PL353_ECC_BITS_BYTEOFF_MASK;
+		/* bits [2:0] of error code is bit offset */
+		bit_addr = ecc_odd & PL353_ECC_BITS_BITOFF_MASK;
+		/* Toggling error bit */
+		buf[byte_addr] ^= (BIT(bit_addr));
+		return 1;
+	}
+
+	/* one error in parity */
+	if (hweight32(ecc_odd | ecc_even) == 1)
+		return 1;
+
+	/* Uncorrectable error */
+	return -1;
+}
+
+static void pl353_prepare_cmd(struct mtd_info *mtd, struct nand_chip *chip,
+			      int page, int column, int start_cmd, int end_cmd,
+			      bool read)
+{
+	unsigned long data_phase_addr;
+	u32 end_cmd_valid = 0;
+	unsigned long cmd_phase_addr = 0, cmd_data = 0;
+
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+
+	end_cmd_valid = read ? 1 : 0;
+
+	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
+			 ((xnfc->addr_cycles
+			 << ADDR_CYCLES_SHIFT) |
+			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
+			 (COMMAND_PHASE) |
+			 (end_cmd << END_CMD_SHIFT) |
+			 (start_cmd << START_CMD_SHIFT));
+
+	/* Get the data phase address */
+	data_phase_addr = (unsigned long __force)xnfc->nand_base +
+			  ((0x0 << CLEAR_CS_SHIFT) |
+			  (0 << END_CMD_VALID_SHIFT) |
+			  (DATA_PHASE) |
+			  (end_cmd << END_CMD_SHIFT) |
+			  (0x0 << ECC_LAST_SHIFT));
+
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+
+	if (chip->options & NAND_BUSWIDTH_16)
+		column /= 2;
+	cmd_data = column;
+	if (mtd->writesize > PL353_NAND_ECC_SIZE) {
+		cmd_data |= page << 16;
+		/* Another address cycle for devices > 128MiB */
+		if (chip->options & NAND_ROW_ADDR_3) {
+			writel_relaxed(cmd_data,
+				       (void __iomem * __force)cmd_phase_addr);
+			cmd_data = (page >> 16);
+		}
+	} else {
+		cmd_data |= page << 8;
+	}
+
+	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr);
+}
+
+/**
+ * pl353_nand_read_oob - [REPLACEABLE] the most common OOB data read function
+ * @mtd:	Pointer to the mtd info structure
+ * @chip:	Pointer to the NAND chip info structure
+ * @page:	Page number to read
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
+			       int page)
+{
+	unsigned long data_phase_addr;
+	u8 *p;
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
+
+	chip->pagebuf = -1;
+	if (mtd->writesize < PL353_NAND_ECC_SIZE)
+		return 0;
+
+	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_READ0,
+			  NAND_CMD_READSTART, 1);
+
+	nand_wait_ready(mtd);
+
+	p = chip->oob_poi;
+	pl353_nand_read_data_op(chip, p,
+				(mtd->oobsize -
+				PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	return 0;
+}
+
+/**
+ * pl353_nand_write_oob - [REPLACEABLE] the most common OOB data write function
+ * @mtd:	Pointer to the mtd info structure
+ * @chip:	Pointer to the NAND chip info structure
+ * @page:	Page number to write
+ *
+ * Return:	Zero on success and EIO on failure
+ */
+static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
+				int page)
+{
+	const u8 *buf = chip->oob_poi;
+	unsigned long data_phase_addr;
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
+	u32 addrcycles = 0;
+
+	chip->pagebuf = -1;
+	addrcycles = xnfc->addr_cycles;
+	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_SEQIN,
+			  NAND_CMD_PAGEPROG, 0);
+
+	pl353_nand_write_data_op(mtd, buf,
+				 (mtd->oobsize -
+				 PL353_NAND_LAST_TRANSFER_LENGTH));
+	buf += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+	pl353_nand_write_data_op(mtd, buf, PL353_NAND_LAST_TRANSFER_LENGTH);
+	nand_wait_ready(mtd);
+
+	return 0;
+}
+
+/**
+ * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
+ * @mtd:		Pointer to the mtd info structure
+ * @chip:		Pointer to the NAND chip info structure
+ * @buf:		Pointer to the data buffer
+ * @oob_required:	Caller requires OOB data read to chip->oob_poi
+ * @page:		Page number to read
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_read_page_raw(struct mtd_info *mtd,
+				    struct nand_chip *chip,
+				    u8 *buf, int oob_required, int page)
+{
+	unsigned long data_phase_addr;
+	u8 *p;
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
+
+	pl353_nand_read_data_op(chip, buf, mtd->writesize);
+	p = chip->oob_poi;
+	pl353_nand_read_data_op(chip, p,
+				(mtd->oobsize -
+				PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+
+	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	return 0;
+}
+
+/**
+ * pl353_nand_write_page_raw - [Intern] raw page write function
+ * @mtd:		Pointer to the mtd info structure
+ * @chip:		Pointer to the NAND chip info structure
+ * @buf:		Pointer to the data buffer
+ * @oob_required:	Caller requires OOB data read to chip->oob_poi
+ * @page:		Page number to write
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_write_page_raw(struct mtd_info *mtd,
+				     struct nand_chip *chip,
+				     const u8 *buf, int oob_required,
+				     int page)
+{
+	unsigned long data_phase_addr;
+	u8 *p;
+
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
+
+	pl353_nand_write_data_op(mtd, buf, mtd->writesize);
+	p = chip->oob_poi;
+	pl353_nand_write_data_op(mtd, p,
+				 (mtd->oobsize -
+				 PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	return 0;
+}
+
+/**
+ * nand_write_page_hwecc - Hardware ECC based page write function
+ * @mtd:		Pointer to the mtd info structure
+ * @chip:		Pointer to the NAND chip info structure
+ * @buf:		Pointer to the data buffer
+ * @oob_required:	Caller requires OOB data read to chip->oob_poi
+ * @page:		Page number to write
+ *
+ * This functions writes data and hardware generated ECC values in to the page.
+ *
+ * Return:	Always return zero
+ */
+static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
+				       struct nand_chip *chip,
+				       const u8 *buf, int oob_required,
+				       int page)
+{
+	int eccsize = chip->ecc.size;
+	int eccsteps = chip->ecc.steps;
+	u8 *ecc_calc = chip->ecc.calc_buf;
+	u8 *oob_ptr;
+	const u8 *p = buf;
+	u32 ret;
+	unsigned long data_phase_addr;
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
+
+	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_SEQIN,
+			  NAND_CMD_PAGEPROG, 0);
+
+	for ( ; (eccsteps - 1); eccsteps--) {
+		pl353_nand_write_data_op(mtd, p, eccsize);
+		p += eccsize;
+	}
+	pl353_nand_write_data_op(mtd, p,
+				 (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Set ECC Last bit to 1 */
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_ECC_LAST;
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	p = buf;
+	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
+
+	/* Wait for ECC to be calculated and read the error values */
+	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi,
+					 0, chip->ecc.total);
+	if (ret)
+		return ret;
+	/* Clear ECC last bit */
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr &= ~PL353_NAND_ECC_LAST;
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+
+	/* Write the spare area with ECC bytes */
+	oob_ptr = chip->oob_poi;
+	pl353_nand_write_data_op(mtd, oob_ptr,
+				 (mtd->oobsize -
+				 PL353_NAND_LAST_TRANSFER_LENGTH));
+
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+	pl353_nand_write_data_op(mtd, oob_ptr, PL353_NAND_LAST_TRANSFER_LENGTH);
+	nand_wait_ready(mtd);
+
+	return 0;
+}
+
+/**
+ * pl353_nand_read_page_hwecc - Hardware ECC based page read function
+ * @mtd:		Pointer to the mtd info structure
+ * @chip:		Pointer to the NAND chip info structure
+ * @buf:		Pointer to the buffer to store read data
+ * @oob_required:	Caller requires OOB data read to chip->oob_poi
+ * @page:		Page number to read
+ *
+ * This functions reads data and checks the data integrity by comparing
+ * hardware generated ECC values and read ECC values from spare area.
+ * There is a limitation in SMC controller, that we must set ECC LAST on
+ * last data phase access, to tell ECC block not to expect any data further.
+ * Ex:  When number of ECC STEPS are 4, then till 3 we will write to flash
+ * using SMC with HW ECC enabled. And for the last ECC STEP, we will subtract
+ * 4bytes from page size, and will initiate a transfer. And the remaining 4 as
+ * one more transfer with ECC_LAST bit set in NAND data phase register to
+ * notify ECC block not to expect any more data. The last block should be align
+ * with end of 512 byte block. Because of this limitation, we are not using
+ * core routines.
+ *
+ * Return:	0 always and updates ECC operation status in to MTD structure
+ */
+static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
+				      struct nand_chip *chip,
+				      u8 *buf, int oob_required, int page)
+{
+	int i, stat, eccsize = chip->ecc.size;
+	int eccbytes = chip->ecc.bytes;
+	int eccsteps = chip->ecc.steps;
+	u8 *p = buf;
+	u8 *ecc_calc = chip->ecc.calc_buf;
+	u8 *ecc = chip->ecc.code_buf;
+	unsigned int max_bitflips = 0;
+	u8 *oob_ptr;
+	u32 ret;
+	unsigned long data_phase_addr;
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
+
+	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_READ0,
+			  NAND_CMD_READSTART, 1);
+	nand_wait_ready(mtd);
+
+	for ( ; (eccsteps - 1); eccsteps--) {
+		pl353_nand_read_data_op(chip, p, eccsize);
+		p += eccsize;
+	}
+	pl353_nand_read_data_op(chip, p,
+				(eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
+	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Set ECC Last bit to 1 */
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_ECC_LAST;
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	/* Read the calculated ECC value */
+	p = buf;
+	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
+
+	/* Clear ECC last bit */
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr &= ~PL353_NAND_ECC_LAST;
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+
+	/* Read the stored ECC value */
+	oob_ptr = chip->oob_poi;
+	pl353_nand_read_data_op(chip, oob_ptr,
+				(mtd->oobsize -
+				PL353_NAND_LAST_TRANSFER_LENGTH));
+
+	/* de-assert chip select */
+	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
+	data_phase_addr -= nand_offset;
+	data_phase_addr |= PL353_NAND_CLEAR_CS;
+	data_phase_addr += nand_offset;
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+
+	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
+	pl353_nand_read_data_op(chip, oob_ptr, PL353_NAND_LAST_TRANSFER_LENGTH);
+
+	ret = mtd_ooblayout_get_eccbytes(mtd, ecc, chip->oob_poi, 0,
+					 chip->ecc.total);
+	if (ret)
+		return ret;
+
+	eccsteps = chip->ecc.steps;
+	p = buf;
+
+	/* Check ECC error for all blocks and correct if it is correctable */
+	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
+		stat = chip->ecc.correct(mtd, p, &ecc[i], &ecc_calc[i]);
+		if (stat < 0) {
+			mtd->ecc_stats.failed++;
+		} else {
+			mtd->ecc_stats.corrected += stat;
+			max_bitflips = max_t(unsigned int, max_bitflips, stat);
+		}
+	}
+
+	return max_bitflips;
+}
+
+/**
+ * pl353_nand_select_chip - Select the flash device
+ * @mtd:	Pointer to the mtd info structure
+ * @chip:	Pointer to the NAND chip info structure
+ *
+ * This function is empty as the NAND controller handles chip select line
+ * internally based on the chip address passed in command and data phase.
+ */
+static void pl353_nand_select_chip(struct mtd_info *mtd, int chip)
+{
+}
+
+/* NAND framework ->exec_op() hooks and related helpers */
+static void pl353_nfc_parse_instructions(struct nand_chip *chip,
+					 const struct nand_subop *subop,
+					 struct pl353_nfc_op *nfc_op)
+{
+	const struct nand_op_instr *instr = NULL;
+	unsigned int op_id, offset, naddrs;
+	int i, len;
+	const u8 *addrs;
+
+	memset(nfc_op, 0, sizeof(struct pl353_nfc_op));
+	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
+		nfc_op->len = nand_subop_get_data_len(subop, op_id);
+		len = nand_subop_get_data_len(subop, op_id);
+		instr = &subop->instrs[op_id];
+
+		switch (instr->type) {
+		case NAND_OP_CMD_INSTR:
+			nfc_op->type = NAND_OP_CMD_INSTR;
+			if (op_id)
+				nfc_op->cmnds[1] = instr->ctx.cmd.opcode;
+			else
+				nfc_op->cmnds[0] = instr->ctx.cmd.opcode;
+			nfc_op->cle_ale_delay_ns = instr->delay_ns;
+			break;
+
+		case NAND_OP_ADDR_INSTR:
+			offset = nand_subop_get_addr_start_off(subop, op_id);
+			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
+			addrs = &instr->ctx.addr.addrs[offset];
+			nfc_op->addrs = instr->ctx.addr.addrs[offset];
+			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) {
+				nfc_op->addrs |= instr->ctx.addr.addrs[i] <<
+						 (8 * i);
+			}
+
+			if (naddrs >= 5)
+				nfc_op->addr5 = addrs[4];
+			if (naddrs >= 6)
+				nfc_op->addr6 = addrs[5];
+			nfc_op->naddrs = nand_subop_get_num_addr_cyc(subop,
+								     op_id);
+			nfc_op->cle_ale_delay_ns = instr->delay_ns;
+			break;
+
+		case NAND_OP_DATA_IN_INSTR:
+			nfc_op->data_instr = instr;
+			nfc_op->type = NAND_OP_DATA_IN_INSTR;
+			nfc_op->data_instr_idx = op_id;
+			break;
+
+		case NAND_OP_DATA_OUT_INSTR:
+			nfc_op->data_instr = instr;
+			nfc_op->type = NAND_OP_DATA_IN_INSTR;
+			nfc_op->data_instr_idx = op_id;
+			break;
+
+		case NAND_OP_WAITRDY_INSTR:
+			nfc_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
+			nfc_op->rdy_delay_ns = instr->delay_ns;
+			break;
+		}
+	}
+}
+
+static void cond_delay(unsigned int ns)
+{
+	if (!ns)
+		return;
+
+	if (ns < 10000)
+		ndelay(ns);
+	else
+		udelay(DIV_ROUND_UP(ns, 1000));
+}
+
+/**
+ * pl353_nand_cmd_function - Send command to NAND device
+ * @chip:	Pointer to the NAND chip info structure
+ * @subop:	Pointer to array of instructions
+ * Return:	Always return zero
+ */
+static int pl353_nand_cmd_function(struct nand_chip *chip,
+				   const struct nand_subop *subop)
+{
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	const struct nand_op_instr *instr;
+	struct pl353_nfc_op nfc_op = {};
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	unsigned long cmd_data = 0, end_cmd_valid = 0;
+	unsigned long cmd_phase_addr, data_phase_addr, end_cmd;
+	unsigned int op_id, len, offset;
+	bool reading;
+
+	pl353_nfc_parse_instructions(chip, subop, &nfc_op);
+	instr = nfc_op.data_instr;
+	op_id = nfc_op.data_instr_idx;
+	len = nand_subop_get_data_len(subop, op_id);
+	offset = nand_subop_get_data_start_off(subop, op_id);
+
+	pl353_smc_clr_nand_int();
+	/* Get the command phase address */
+	if (nfc_op.cmnds[1] != 0) {
+		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN)
+			end_cmd_valid = 0;
+		else
+			end_cmd_valid = 1;
+		end_cmd = nfc_op.cmnds[1];
+	}  else {
+		end_cmd = 0x0;
+	}
+
+	/*
+	 * The SMC defines two phases of commands when transferring data to or
+	 * from NAND flash.
+	 * Command phase: Commands and optional address information are written
+	 * to the NAND flash.The command and address can be associated with
+	 * either a data phase operation to write to or read from the array,
+	 * or a status/ID register transfer.
+	 * Data phase: Data is either written to or read from the NAND flash.
+	 * This data can be either data transferred to or from the array,
+	 * or status/ID register information.
+	 */
+	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
+			 ((nfc_op.naddrs << ADDR_CYCLES_SHIFT) |
+			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
+			 (COMMAND_PHASE) |
+			 (end_cmd << END_CMD_SHIFT) |
+			 (nfc_op.cmnds[0] << START_CMD_SHIFT));
+
+	/* Get the data phase address */
+	end_cmd_valid = 0;
+
+	data_phase_addr = (unsigned long __force)xnfc->nand_base +
+			  ((0x0 << CLEAR_CS_SHIFT) |
+			  (end_cmd_valid << END_CMD_VALID_SHIFT) |
+			  (DATA_PHASE) |
+			  (end_cmd << END_CMD_SHIFT) |
+			  (0x0 << ECC_LAST_SHIFT));
+	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
+
+	/* Command phase AXI Read & Write */
+	if (nfc_op.naddrs >= 5) {
+		if (mtd->writesize > PL353_NAND_ECC_SIZE) {
+			cmd_data = nfc_op.addrs;
+			/* Another address cycle for devices > 128MiB */
+			if (chip->options & NAND_ROW_ADDR_3) {
+				writel_relaxed(cmd_data,
+					       (void __iomem * __force)
+					       cmd_phase_addr);
+				cmd_data = nfc_op.addr5;
+				if (nfc_op.naddrs >= 6)
+					cmd_data |= (nfc_op.addr6 << 8);
+			}
+		}
+	}  else {
+		if (nfc_op.addrs != -1) {
+			int column = nfc_op.addrs;
+			/*
+			 * Change read/write column, read id etc
+			 * Adjust columns for 16 bit bus width
+			 */
+			if ((chip->options & NAND_BUSWIDTH_16) &&
+			    (nfc_op.cmnds[0] == NAND_CMD_READ0 ||
+				nfc_op.cmnds[0] == NAND_CMD_SEQIN ||
+				nfc_op.cmnds[0] == NAND_CMD_RNDOUT ||
+				nfc_op.cmnds[0] == NAND_CMD_RNDIN)) {
+				column >>= 1;
+			}
+			cmd_data = column;
+		}
+	}
+	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr);
+
+	if (!nfc_op.data_instr) {
+		if (nfc_op.rdy_timeout_ms)
+			nand_wait_ready(mtd);
+		return 0;
+	}
+
+	reading = (nfc_op.data_instr->type == NAND_OP_DATA_IN_INSTR);
+	if (!reading) {
+		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN &&
+		    nfc_op.cmnds[1] == NAND_CMD_PAGEPROG) {
+			pl353_nand_write_page_raw(mtd, chip,
+						  instr->ctx.data.buf.out, 0,
+						  nfc_op.addrs);
+
+		} else {
+			pl353_nand_write_data_op(mtd, instr->ctx.data.buf.out,
+						 len);
+		}
+		if (nfc_op.rdy_timeout_ms)
+			nand_wait_ready(mtd);
+		cond_delay(nfc_op.rdy_delay_ns);
+	}
+	if (reading) {
+		cond_delay(nfc_op.rdy_delay_ns);
+		if (nfc_op.rdy_timeout_ms)
+			nand_wait_ready(mtd);
+		pl353_nand_read_data_op(chip, instr->ctx.data.buf.in, len);
+	}
+
+	return 0;
+}
+
+static const struct nand_op_parser pl353_nfc_op_parser = NAND_OP_PARSER
+	(NAND_OP_PARSER_PATTERN
+		(pl353_nand_cmd_function,
+		NAND_OP_PARSER_PAT_CMD_ELEM(true),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
+		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
+	NAND_OP_PARSER_PATTERN
+		(pl353_nand_cmd_function,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 7),
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false),
+		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
+	NAND_OP_PARSER_PATTERN
+		(pl353_nand_cmd_function,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
+		NAND_OP_PARSER_PAT_CMD_ELEM(true),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
+	NAND_OP_PARSER_PATTERN
+		(pl353_nand_cmd_function,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false),
+		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 8),
+		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 2048),
+		NAND_OP_PARSER_PAT_CMD_ELEM(true),
+		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
+	NAND_OP_PARSER_PATTERN
+		(pl353_nand_cmd_function,
+		NAND_OP_PARSER_PAT_CMD_ELEM(false)),
+	);
+
+static int pl353_nfc_exec_op(struct nand_chip *chip,
+			     const struct nand_operation *op,
+			     bool check_only)
+{
+	return nand_op_parser_exec_op(chip, &pl353_nfc_op_parser,
+					      op, check_only);
+}
+
+/**
+ * pl353_nand_device_ready - Check device ready/busy line
+ * @mtd:	Pointer to the mtd_info structure
+ *
+ * Return:	0 on busy or 1 on ready state
+ */
+static int pl353_nand_device_ready(struct mtd_info *mtd)
+{
+	if (pl353_smc_get_nand_int_status_raw()) {
+		pl353_smc_clr_nand_int();
+		return 1;
+	}
+
+	return 0;
+}
+
+/**
+ * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
+ * @mtd:	Pointer to the mtd_info structure
+ * @ecc:	Pointer to ECC control structure
+ * @ecc_mode:	ondie ecc status
+ *
+ * This function initializes the ecc block and functional pointers as per the
+ * ecc mode
+ *
+ * Return:	0 on success or negative errno.
+ */
+static int pl353_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
+				int ecc_mode)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	int err = 0;
+
+	if (ecc_mode == NAND_ECC_ON_DIE) {
+		pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
+		/*
+		 * On-Die ECC spare bytes offset 8 is used for ECC codes
+		 * Use the BBT pattern descriptors
+		 */
+		chip->bbt_td = &bbt_main_descr;
+		chip->bbt_md = &bbt_mirror_descr;
+		bitmap_set(chip->parameters.get_feature_list,
+			   ONFI_FEATURE_ON_DIE_ECC, ONFI_FEATURE_ON_DIE_ECC_EN);
+		bitmap_set(chip->parameters.set_feature_list,
+			   ONFI_FEATURE_ON_DIE_ECC, ONFI_FEATURE_ON_DIE_ECC_EN);
+	} else {
+		ecc->read_oob = pl353_nand_read_oob;
+		ecc->write_oob = pl353_nand_write_oob;
+
+		ecc->mode = NAND_ECC_HW;
+		/* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
+		ecc->bytes = 3;
+		ecc->strength = 1;
+		ecc->calculate = pl353_nand_calculate_hwecc;
+		ecc->correct = pl353_nand_correct_data;
+		ecc->read_page = pl353_nand_read_page_hwecc;
+		ecc->size = PL353_NAND_ECC_SIZE;
+		ecc->write_page = pl353_nand_write_page_hwecc;
+		pl353_smc_set_ecc_pg_size(mtd->writesize);
+		switch (mtd->writesize) {
+		case SZ_512:
+		case SZ_1K:
+		case SZ_2K:
+			pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_APB);
+			break;
+		default:
+			ecc->calculate = nand_calculate_ecc;
+			ecc->correct = nand_correct_data;
+			ecc->size = 256;
+			break;
+		}
+		if (mtd->writesize <= SZ_512)
+			xnfc->addr_cycles = 1;
+		else
+			xnfc->addr_cycles = 2;
+
+		if (chip->options & NAND_ROW_ADDR_3)
+			xnfc->addr_cycles += 3;
+		else
+			xnfc->addr_cycles += 2;
+
+		if (mtd->oobsize == 16) {
+			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout16_ops);
+		} else if (mtd->oobsize == 64) {
+			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout64_ops);
+		} else {
+			err = -ENXIO;
+			dev_err(xnfc->dev, "Unsupported oob Layout\n");
+		}
+	}
+	return err;
+}
+
+static int pl353_setup_data_interface(struct mtd_info *mtd, int csline,
+				       const struct nand_data_interface *conf)
+{
+	struct nand_chip *chip = mtd_to_nand(mtd);
+	struct pl353_nand_info *xnfc =
+		container_of(chip, struct pl353_nand_info, chip);
+	const struct nand_sdr_timings *sdr;
+	u32 timings[7], mckperiodps;
+
+	sdr = nand_get_sdr_timings(conf);
+	if (IS_ERR(sdr))
+		return PTR_ERR(sdr);
+
+	/*
+	 * SDR timings are given in pico-seconds while NFC timings must be
+	 * expressed in NAND controller clock cycles.
+	 */
+	mckperiodps = NSEC_PER_SEC / clk_get_rate(xnfc->mclk);
+	mckperiodps *= 1000;
+	if (sdr->tRC_min <= 20000)
+		/*
+		 * PL353 SMC needs one extra read cycle in SDR Mode 5
+		 * This is not written anywhere in the datasheet but
+		 * the results observed during testing.
+		 */
+		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps) + 1;
+	else
+		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps);
+
+	timings[1] = DIV_ROUND_UP(sdr->tWC_min, mckperiodps);
+	/*
+	 * For all SDR modes, PL353 SMC needs tREA max value as 1
+	 * These results observed during testing.
+	 */
+	timings[2] = PL353_TREA_MAX_VALUE;
+	timings[3] = DIV_ROUND_UP(sdr->tWP_min, mckperiodps);
+	timings[4] = DIV_ROUND_UP(sdr->tCLR_min, mckperiodps);
+	timings[5] = DIV_ROUND_UP(sdr->tAR_min, mckperiodps);
+	timings[6] = DIV_ROUND_UP(sdr->tRR_min, mckperiodps);
+
+	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
+		return 0;
+
+	pl353_smc_set_cycles(timings);
+
+	return 0;
+}
+/**
+ * pl353_nand_probe - Probe method for the NAND driver
+ * @pdev:	Pointer to the platform_device structure
+ *
+ * This function initializes the driver data structures and the hardware.
+ * The NAND driver has dependency with the pl353_smc memory controller
+ * driver for initializing the NAND timing parameters, bus width, ECC modes,
+ * control and status information.
+ *
+ * Return:	0 on success or error value on failure
+ */
+static int pl353_nand_probe(struct platform_device *pdev)
+{
+	struct pl353_nand_info *xnfc;
+	struct mtd_info *mtd;
+	struct nand_chip *chip;
+	struct resource *res;
+	struct device_node *np;
+	u32 ret;
+
+	xnfc = devm_kzalloc(&pdev->dev, sizeof(*xnfc), GFP_KERNEL);
+	if (!xnfc)
+		return -ENOMEM;
+	xnfc->dev = &pdev->dev;
+	/* Map physical address of NAND flash */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	xnfc->nand_base = devm_ioremap_resource(xnfc->dev, res);
+	if (IS_ERR(xnfc->nand_base))
+		return PTR_ERR(xnfc->nand_base);
+
+	chip = &xnfc->chip;
+	mtd = nand_to_mtd(chip);
+	chip->exec_op = pl353_nfc_exec_op;
+	nand_set_controller_data(chip, xnfc);
+	mtd->priv = chip;
+	mtd->owner = THIS_MODULE;
+	if (!mtd->name) {
+		/*
+		 * If the new bindings are used and the bootloader has not been
+		 * updated to pass a new mtdparts parameter on the cmdline, you
+		 * should define the following property in your NAND node, ie:
+		 *
+		 *	label = "pl353-nand";
+		 *
+		 * This way, mtd->name will be set by the core when
+		 * nand_set_flash_node() is called.
+		 */
+		mtd->name = devm_kasprintf(xnfc->dev, GFP_KERNEL,
+					   "%s", PL353_NAND_DRIVER_NAME);
+		if (!mtd->name) {
+			dev_err(xnfc->dev, "Failed to allocate mtd->name\n");
+			return -ENOMEM;
+		}
+	}
+	nand_set_flash_node(chip, xnfc->dev->of_node);
+
+	/* Set the driver entry points for MTD */
+	chip->dev_ready = pl353_nand_device_ready;
+	chip->select_chip = pl353_nand_select_chip;
+	/* If we don't set this delay driver sets 20us by default */
+	np = of_get_next_parent(xnfc->dev->of_node);
+	xnfc->mclk = of_clk_get(np, 0);
+	if (IS_ERR(xnfc->mclk)) {
+		dev_err(xnfc->dev, "Failed to retrieve MCK clk\n");
+		return PTR_ERR(xnfc->mclk);
+	}
+	chip->chip_delay = 30;
+	/* Set the device option and flash width */
+	chip->options = NAND_BUSWIDTH_AUTO;
+	chip->bbt_options = NAND_BBT_USE_FLASH;
+	platform_set_drvdata(pdev, xnfc);
+	chip->setup_data_interface = pl353_setup_data_interface;
+	/* first scan to find the device and get the page size */
+	if (nand_scan_ident(mtd, 1, NULL)) {
+		dev_err(xnfc->dev, "nand_scan_ident for NAND failed\n");
+		return -ENXIO;
+	}
+	ret = pl353_nand_ecc_init(mtd, &chip->ecc, chip->ecc.mode);
+	if (chip->options & NAND_BUSWIDTH_16)
+		pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_16);
+	/* second phase scan */
+	if (nand_scan_tail(mtd)) {
+		dev_err(xnfc->dev, "nand_scan_tail for NAND failed\n");
+		return -ENXIO;
+	}
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		dev_err(xnfc->dev, "Failed to register mtd device: %d\n", ret);
+		nand_cleanup(chip);
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * pl353_nand_remove - Remove method for the NAND driver
+ * @pdev:	Pointer to the platform_device structure
+ *
+ * This function is called if the driver module is being unloaded. It frees all
+ * resources allocated to the device.
+ *
+ * Return:	0 on success or error value on failure
+ */
+static int pl353_nand_remove(struct platform_device *pdev)
+{
+	struct pl353_nand_info *xnfc = platform_get_drvdata(pdev);
+	struct mtd_info *mtd = nand_to_mtd(&xnfc->chip);
+
+	/* Release resources, unregister device */
+	nand_release(mtd);
+
+	return 0;
+}
+
+/* Match table for device tree binding */
+static const struct of_device_id pl353_nand_of_match[] = {
+	{ .compatible = "arm,pl353-nand-r2p1" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, pl353_nand_of_match);
+
+/*
+ * pl353_nand_driver - This structure defines the NAND subsystem platform driver
+ */
+static struct platform_driver pl353_nand_driver = {
+	.probe		= pl353_nand_probe,
+	.remove		= pl353_nand_remove,
+	.driver		= {
+		.name	= PL353_NAND_DRIVER_NAME,
+		.of_match_table = pl353_nand_of_match,
+	},
+};
+
+module_platform_driver(pl353_nand_driver);
+
+MODULE_AUTHOR("Xilinx, Inc.");
+MODULE_ALIAS("platform:" PL353_NAND_DRIVER_NAME);
+MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
+MODULE_LICENSE("GPL");
-- 
2.7.4

Re: [LINUX PATCH v11 1/3] dt-bindings: memory: Add pl353 smc controller devicetree binding information

[Linus Walleij]

On Wed, Jul 11, 2018 at 9:37 AM Naga Sureshkumar Relli
<naga.sureshkumar.relli@xilinx.com> wrote:

> Add pl353 static memory controller devicetree binding information.
>
> Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
> ---
> Changes in v11:

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Thanks!

Yours,
Linus Walleij

Re: [LINUX PATCH v11 2/3] memory: pl353: Add driver for arm pl353 static memory controller

[Linus Walleij]

On Wed, Jul 11, 2018 at 9:37 AM Naga Sureshkumar Relli
<naga.sureshkumar.relli@xilinx.com> wrote:

> Add driver for arm pl353 static memory controller. This controller is used in
> Xilinx Zynq SoC for interfacing the NAND and NOR/SRAM memory devices.
>
> Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
> ---
> Changes in v11:
>  - Added amba device registration and removed platform device, since it
>    is an ARM Primecell Peripheral and it should register as an amba device
>    as per Linus Walleji.

This looks good to me!
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

RE: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

[Naga Sureshkumar Relli]

Hi Miquel,

Could you please provide your review comments?
I will address if any.

Thanks,
Naga Sureshkumar Relli.

> -----Original Message-----
> From: Naga Sureshkumar Relli [mailto:naga.sureshkumar.relli@xilinx.com]
> Sent: Wednesday, July 11, 2018 1:07 PM
> To: boris.brezillon@bootlin.com; richard@nod.at; dwmw2@infradead.org;
> computersforpeace@gmail.com; marek.vasut@gmail.com; f.fainelli@gmail.com;
> mmayer@broadcom.com; rogerq@ti.com; ladis@linux-mips.org; ada@thorsis.co;
> honghui.zhang@mediatek.com; miquel.raynal@bootlin.com; linus.walleij@linaro.org
> Cc: linux-mtd@lists.infradead.org; linux-kernel@vger.kernel.org;
> nagasureshkumarrelli@gmail.com; Michal Simek <michals@xilinx.com>; Naga Sureshkumar
> Relli <nagasure@xilinx.com>
> Subject: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc
> nand interface
> 
> Add driver for arm pl353 static memory controller nand interface with HW ECC support. This
> controller is used in Xilinx Zynq SoC for interfacing the NAND flash memory.
> 
> Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
> ---
> Changes in v11:
>  - Removed Documentation patch and added the required info in driver as
>    per Boris comments.
>  - Removed unwanted variables from pl353_nand_info as per Miquel comments
>  - Removed IO_ADDR_R/W.
>  - Replaced onhot() with hweight32()
>  - Defined macros for static values in function pl353_nand_correct_data()
>  - Removed all unnecessary delays
>  - Used nand_wait_ready() where ever is required
>  - Modifed the pl353_setup_data_interface() logic as per Miquel comments.
>  - Taken array instead of 7 values in pl353_setup_data_interface() and pass
>    it to smc driver.
>  - Added check to collect the return value of mtd_device_register().
> Changes in 10:
>  - Typos correction like nand to NAND and soc to SOC etc..
>  - Defined macros for the values in pl353_nand_calculate_hwecc()
>  - Modifed ecc_status from int to char in pl353_nand_calculate_hwecc()
>  - Changed the return type form int to bool to the function
>    onehot()
>  - Removed udelay(1000) in pl353_cmd_function, as it is not required
>  - Dropped ecc->hwctl = NULL in pl353_ecc_init()
>  - Added an error message in pl353_ecc_init(), when there is no matching
>    oobsize
>  - Changed the variable from xnand to xnfc
>  - Added logic to get mtd->name from DT, if it is specified in DT Changes in v9:
>  - Addressed the below comments given by Miquel
>  - instead of using pl353_nand_write32, use directly writel_relaxed
>  - Fixed check patch warnings
>  - Renamed write_buf/read_buf to write_data_op/read_data_op
>  - use BIT macro instead of 1 << nr
>  - Use NAND_ROW_ADDR_3 flag
>  - Use nand_wait_ready()
>  - Removed swecc functions
>  - Use address cycles as per size, instead of reading it from Parameter page
>  - Instead of writing too many patterns, use optional property Changes in v8:
>  - Added exec_op() implementation
>  - Fixed the below v7 review comments
>  - removed mtd_info from pl353_nand_info struct
>  - Corrected ecc layout offsets
>  - Added on-die ecc support
> Changes in v7:
>  - Currently not implemented the memclk rate adjustments. I will
>    look into this later and once the basic driver is accepted.
>  - Fixed GPL licence ident
> Changes in v6:
>  - Fixed the checkpatch.pl reported warnings
>  - Using the address cycles information from the onfi param page
>    earlier it is hardcoded to 5 in driver Changes in v5:
>  - Configure the nand timing parameters as per the onfi spec Changes in v4:
>  - Updated the driver to sync with pl353_smc driver APIs Changes in v3:
>  - implemented the proper error codes
>  - further breakdown this patch to multiple sets
>  - added the controller and driver details to Documentation section
>  - updated the licenece to GPLv2
>  - reorganized the pl353_nand_ecc_init function Changes in v2:
>  - use "depends on" rather than "select" option in kconfig
>  - remove unused variable parts
> ---
>  drivers/mtd/nand/raw/Kconfig      |    7 +
>  drivers/mtd/nand/raw/Makefile     |    1 +
>  drivers/mtd/nand/raw/pl353_nand.c | 1314
> +++++++++++++++++++++++++++++++++++++
>  3 files changed, 1322 insertions(+)
>  create mode 100644 drivers/mtd/nand/raw/pl353_nand.c
> 
> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig index
> 6871ff0..1c5d528 100644
> --- a/drivers/mtd/nand/raw/Kconfig
> +++ b/drivers/mtd/nand/raw/Kconfig
> @@ -530,4 +530,11 @@ config MTD_NAND_MTK
>  	  Enables support for NAND controller on MTK SoCs.
>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
> 
> +config MTD_NAND_PL353
> +	tristate "ARM Pl353 NAND flash driver"
> +	depends on MTD_NAND && ARM
> +	depends on PL353_SMC
> +	help
> +	  Enables support for PrimeCell Static Memory Controller PL353.
> +
>  endif # MTD_NAND
> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile index
> 165b7ef..1c702e1 100644
> --- a/drivers/mtd/nand/raw/Makefile
> +++ b/drivers/mtd/nand/raw/Makefile
> @@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
>  obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
>  obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
>  obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
> +obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o
> 
>  nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o  nand-objs += nand_amd.o
> diff --git a/drivers/mtd/nand/raw/pl353_nand.c b/drivers/mtd/nand/raw/pl353_nand.c
> new file mode 100644
> index 0000000..3fa9ba07
> --- /dev/null
> +++ b/drivers/mtd/nand/raw/pl353_nand.c
> @@ -0,0 +1,1314 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ARM PL353 NAND flash controller driver
> + *
> + * Copyright (C) 2017 Xilinx, Inc
> + * Author: Punnaiah chowdary kalluri <punnaiah@xilinx.com>
> + * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
> + *
> + */
> +
> +#include <linux/err.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/irq.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/rawnand.h>
> +#include <linux/mtd/nand_ecc.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/pl353-smc.h>
> +#include <linux/clk.h>
> +
> +#define PL353_NAND_DRIVER_NAME "pl353-nand"
> +
> +/* NAND flash driver defines */
> +#define PL353_NAND_CMD_PHASE	1	/* End command valid in command
> phase */
> +#define PL353_NAND_DATA_PHASE	2	/* End command valid in data phase */
> +#define PL353_NAND_ECC_SIZE	512	/* Size of data for ECC operation */
> +
> +/* Flash memory controller operating parameters */
> +
> +#define PL353_NAND_ECC_CONFIG	(BIT(4)  |	/* ECC read at end of page */
> \
> +				 (0 << 5))	/* No Jumping */
> +
> +/* AXI Address definitions */
> +#define START_CMD_SHIFT		3
> +#define END_CMD_SHIFT		11
> +#define END_CMD_VALID_SHIFT	20
> +#define ADDR_CYCLES_SHIFT	21
> +#define CLEAR_CS_SHIFT		21
> +#define ECC_LAST_SHIFT		10
> +#define COMMAND_PHASE		(0 << 19)
> +#define DATA_PHASE		BIT(19)
> +
> +#define PL353_NAND_ECC_LAST	BIT(ECC_LAST_SHIFT)	/* Set ECC_Last */
> +#define PL353_NAND_CLEAR_CS	BIT(CLEAR_CS_SHIFT)	/* Clear chip select */
> +
> +#define ONDIE_ECC_FEATURE_ADDR	0x90
> +#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
> +#define PL353_NAND_DEV_BUSY_TIMEOUT	(1 * HZ)
> +#define PL353_NAND_LAST_TRANSFER_LENGTH	4
> +#define PL353_NAND_ECC_VALID_SHIFT	24
> +#define PL353_NAND_ECC_VALID_MASK	0x40
> +#define PL353_ECC_BITS_BYTEOFF_MASK	0x1FF
> +#define PL353_ECC_BITS_BITOFF_MASK	0x7
> +#define PL353_ECC_BIT_MASK		0xFFF
> +#define PL353_TREA_MAX_VALUE		1
> +
> +struct pl353_nfc_op {
> +	u32 cmnds[4];
> +	u32 thirdrow;
> +	u32 type;
> +	u32 end_cmd;
> +	u32 addrs;
> +	u32 len;
> +	u32 naddrs;
> +	u32 addr5;
> +	u32 addr6;
> +	unsigned int data_instr_idx;
> +	unsigned int rdy_timeout_ms;
> +	unsigned int rdy_delay_ns;
> +	unsigned int cle_ale_delay_ns;
> +	const struct nand_op_instr *data_instr; };
> +
> +/**
> + * struct pl353_nand_info - Defines the NAND flash driver instance
> + * @chip:		NAND chip information structure
> + * @dev:		Parent device (used to print error messages)
> + * @nand_base:		Virtual address of the NAND flash device
> + * @nandaddr:		Virtual address of the NAND flash device for
> + *			data read/writes
> + * @addr_cycles:	Address cycles
> + * @mclk:		Memory controller clock
> + */
> +struct pl353_nand_info {
> +	struct nand_chip chip;
> +	struct device *dev;
> +	void __iomem *nand_base;
> +	void __iomem *nandaddr;
> +	u8 addr_cycles;
> +	struct clk *mclk;
> +};
> +
> +static int pl353_ecc_ooblayout16_ecc(struct mtd_info *mtd, int section,
> +				     struct mtd_oob_region *oobregion) {
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes);
> +	oobregion->length = chip->ecc.bytes;
> +
> +	return 0;
> +}
> +
> +static int pl353_ecc_ooblayout16_free(struct mtd_info *mtd, int section,
> +				      struct mtd_oob_region *oobregion) {
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes) + 8;
> +	oobregion->length = 8;
> +
> +	return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout16_ops = {
> +	.ecc = pl353_ecc_ooblayout16_ecc,
> +	.free = pl353_ecc_ooblayout16_free,
> +};
> +
> +static int pl353_ecc_ooblayout64_ecc(struct mtd_info *mtd, int section,
> +				     struct mtd_oob_region *oobregion) {
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes) + 52;
> +	oobregion->length = chip->ecc.bytes;
> +
> +	return 0;
> +}
> +
> +static int pl353_ecc_ooblayout64_free(struct mtd_info *mtd, int section,
> +				      struct mtd_oob_region *oobregion) {
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section)
> +		return -ERANGE;
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes) + 2;
> +	oobregion->length = 50;
> +
> +	return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout64_ops = {
> +	.ecc = pl353_ecc_ooblayout64_ecc,
> +	.free = pl353_ecc_ooblayout64_free,
> +};
> +
> +/* Generic flash bbt decriptors */
> +static u8 bbt_pattern[] = { 'B', 'b', 't', '0' }; static u8
> +mirror_pattern[] = { '1', 't', 'b', 'B' };
> +
> +static struct nand_bbt_descr bbt_main_descr = {
> +	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |
> NAND_BBT_WRITE
> +		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> +	.offs = 4,
> +	.len = 4,
> +	.veroffs = 20,
> +	.maxblocks = 4,
> +	.pattern = bbt_pattern
> +};
> +
> +static struct nand_bbt_descr bbt_mirror_descr = {
> +	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |
> NAND_BBT_WRITE
> +		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> +	.offs = 4,
> +	.len = 4,
> +	.veroffs = 20,
> +	.maxblocks = 4,
> +	.pattern = mirror_pattern
> +};
> +
> +/**
> + * pl353_nand_read_data_op - read chip data into buffer
> + * @chip:	Pointer to the NAND chip info structure
> + * @in:		Pointer to the buffer to store read data
> + * @len:	Number of bytes to read
> + * Return:	Always return zero
> + */
> +static int pl353_nand_read_data_op(struct nand_chip *chip,
> +				   u8 *in,
> +				   unsigned int len)
> +{
> +	int i;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +
> +	if (IS_ALIGNED((uint32_t)in, sizeof(uint32_t)) &&
> +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> +		u32 *ptr = (u32 *)in;
> +
> +		len /= 4;
> +		for (i = 0; i < len; i++)
> +			ptr[i] = readl(xnfc->nandaddr);
> +	} else {
> +		for (i = 0; i < len; i++)
> +			in[i] = readb(xnfc->nandaddr);
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_write_buf - write buffer to chip
> + * @mtd:	Pointer to the mtd info structure
> + * @buf:	Pointer to the buffer to store write data
> + * @len:	Number of bytes to write
> + */
> +static void pl353_nand_write_data_op(struct mtd_info *mtd, const u8 *buf,
> +				     int len)
> +{
> +	int i;
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +
> +	if (IS_ALIGNED((uint32_t)buf, sizeof(uint32_t)) &&
> +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> +		u32 *ptr = (u32 *)buf;
> +
> +		len /= 4;
> +		for (i = 0; i < len; i++)
> +			writel(ptr[i], xnfc->nandaddr);
> +	} else {
> +		for (i = 0; i < len; i++)
> +			writeb(buf[i], xnfc->nandaddr);
> +	}
> +}
> +
> +/**
> + * pl353_nand_calculate_hwecc - Calculate Hardware ECC
> + * @mtd:	Pointer to the mtd_info structure
> + * @data:	Pointer to the page data
> + * @ecc:	Pointer to the ECC buffer where ECC data needs to be stored
> + *
> + * This function retrieves the Hardware ECC data from the controller
> +and returns
> + * ECC data back to the MTD subsystem.
> + * It operates on a number of 512 byte blocks of NAND memory and can be
> + * programmed to store the ECC codes after the data in memory. For
> +writes,
> + * the ECC is written to the spare area of the page. For reads, the
> +result of
> + * a block ECC check are made available to the device driver.
> + *
> + * ------------------------------------------------------------------------
> + * |               n * 512 blocks                  | extra  | ecc    |     |
> + * |                                               | block  | codes  |     |
> + *
> +-----------------------------------------------------------------------
> +-
> + *
> + * The ECC calculation uses a simple Hamming code, using 1-bit
> +correction 2-bit
> + * detection. It starts when a valid read or write command with a 512
> +byte
> + * aligned address is detected on the memory interface.
> + *
> + * Return:	0 on success or error value on failure
> + */
> +static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
> +				      const u8 *data, u8 *ecc)
> +{
> +	u32 ecc_value;
> +	u8 ecc_reg, ecc_byte, ecc_status;
> +	unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
> +
> +	/* Wait till the ECC operation is complete or timeout */
> +	do {
> +		if (pl353_smc_ecc_is_busy())
> +			cpu_relax();
> +		else
> +			break;
> +	} while (!time_after_eq(jiffies, timeout));
> +
> +	if (time_after_eq(jiffies, timeout)) {
> +		pr_err("%s timed out\n", __func__);
> +		return -ETIMEDOUT;
> +	}
> +
> +	for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
> +		/* Read ECC value for each block */
> +		ecc_value = pl353_smc_get_ecc_val(ecc_reg);
> +		ecc_status = (ecc_value >> PL353_NAND_ECC_VALID_SHIFT);
> +		/* ECC value valid */
> +		if (ecc_status & PL353_NAND_ECC_VALID_MASK) {
> +			for (ecc_byte = 0; ecc_byte < 3; ecc_byte++) {
> +				/* Copy ECC bytes to MTD buffer */
> +				*ecc = ~ecc_value & 0xFF;
> +				ecc_value = ecc_value >> 8;
> +				ecc++;
> +			}
> +		} else {
> +			pr_warn("%s status failed\n", __func__);
> +			return -1;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_correct_data - ECC correction function
> + * @mtd:	Pointer to the mtd_info structure
> + * @buf:	Pointer to the page data
> + * @read_ecc:	Pointer to the ECC value read from spare data area
> + * @calc_ecc:	Pointer to the calculated ECC value
> + *
> + * This function corrects the ECC single bit errors & detects 2-bit errors.
> + *
> + * Return:	0 if no ECC errors found
> + *		1 if single bit error found and corrected.
> + *		-1 if multiple uncorrectable ECC errors found.
> + */
> +static int pl353_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
> +				   unsigned char *read_ecc,
> +				   unsigned char *calc_ecc)
> +{
> +	unsigned char bit_addr;
> +	unsigned int byte_addr;
> +	unsigned short ecc_odd, ecc_even, read_ecc_lower, read_ecc_upper;
> +	unsigned short calc_ecc_lower, calc_ecc_upper;
> +
> +	read_ecc_lower = (read_ecc[0] | (read_ecc[1] << 8)) &
> +			  PL353_ECC_BIT_MASK;
> +	read_ecc_upper = ((read_ecc[1] >> 4) | (read_ecc[2] << 4)) &
> +			  PL353_ECC_BIT_MASK;
> +
> +	calc_ecc_lower = (calc_ecc[0] | (calc_ecc[1] << 8)) &
> +			  PL353_ECC_BIT_MASK;
> +	calc_ecc_upper = ((calc_ecc[1] >> 4) | (calc_ecc[2] << 4)) &
> +			  PL353_ECC_BIT_MASK;
> +
> +	ecc_odd = read_ecc_lower ^ calc_ecc_lower;
> +	ecc_even = read_ecc_upper ^ calc_ecc_upper;
> +
> +	/* no error */
> +	if (!ecc_odd && !ecc_even)
> +		return 0;
> +
> +	if (ecc_odd == (~ecc_even & PL353_ECC_BIT_MASK)) {
> +		/* bits [11:3] of error code is byte offset */
> +		byte_addr = (ecc_odd >> 3) & PL353_ECC_BITS_BYTEOFF_MASK;
> +		/* bits [2:0] of error code is bit offset */
> +		bit_addr = ecc_odd & PL353_ECC_BITS_BITOFF_MASK;
> +		/* Toggling error bit */
> +		buf[byte_addr] ^= (BIT(bit_addr));
> +		return 1;
> +	}
> +
> +	/* one error in parity */
> +	if (hweight32(ecc_odd | ecc_even) == 1)
> +		return 1;
> +
> +	/* Uncorrectable error */
> +	return -1;
> +}
> +
> +static void pl353_prepare_cmd(struct mtd_info *mtd, struct nand_chip *chip,
> +			      int page, int column, int start_cmd, int end_cmd,
> +			      bool read)
> +{
> +	unsigned long data_phase_addr;
> +	u32 end_cmd_valid = 0;
> +	unsigned long cmd_phase_addr = 0, cmd_data = 0;
> +
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +
> +	end_cmd_valid = read ? 1 : 0;
> +
> +	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
> +			 ((xnfc->addr_cycles
> +			 << ADDR_CYCLES_SHIFT) |
> +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> +			 (COMMAND_PHASE) |
> +			 (end_cmd << END_CMD_SHIFT) |
> +			 (start_cmd << START_CMD_SHIFT));
> +
> +	/* Get the data phase address */
> +	data_phase_addr = (unsigned long __force)xnfc->nand_base +
> +			  ((0x0 << CLEAR_CS_SHIFT) |
> +			  (0 << END_CMD_VALID_SHIFT) |
> +			  (DATA_PHASE) |
> +			  (end_cmd << END_CMD_SHIFT) |
> +			  (0x0 << ECC_LAST_SHIFT));
> +
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	if (chip->options & NAND_BUSWIDTH_16)
> +		column /= 2;
> +	cmd_data = column;
> +	if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> +		cmd_data |= page << 16;
> +		/* Another address cycle for devices > 128MiB */
> +		if (chip->options & NAND_ROW_ADDR_3) {
> +			writel_relaxed(cmd_data,
> +				       (void __iomem * __force)cmd_phase_addr);
> +			cmd_data = (page >> 16);
> +		}
> +	} else {
> +		cmd_data |= page << 8;
> +	}
> +
> +	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr); }
> +
> +/**
> + * pl353_nand_read_oob - [REPLACEABLE] the most common OOB data read function
> + * @mtd:	Pointer to the mtd info structure
> + * @chip:	Pointer to the NAND chip info structure
> + * @page:	Page number to read
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
> +			       int page)
> +{
> +	unsigned long data_phase_addr;
> +	u8 *p;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	chip->pagebuf = -1;
> +	if (mtd->writesize < PL353_NAND_ECC_SIZE)
> +		return 0;
> +
> +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_READ0,
> +			  NAND_CMD_READSTART, 1);
> +
> +	nand_wait_ready(mtd);
> +
> +	p = chip->oob_poi;
> +	pl353_nand_read_data_op(chip, p,
> +				(mtd->oobsize -
> +				PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_write_oob - [REPLACEABLE] the most common OOB data write function
> + * @mtd:	Pointer to the mtd info structure
> + * @chip:	Pointer to the NAND chip info structure
> + * @page:	Page number to write
> + *
> + * Return:	Zero on success and EIO on failure
> + */
> +static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
> +				int page)
> +{
> +	const u8 *buf = chip->oob_poi;
> +	unsigned long data_phase_addr;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +	u32 addrcycles = 0;
> +
> +	chip->pagebuf = -1;
> +	addrcycles = xnfc->addr_cycles;
> +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_SEQIN,
> +			  NAND_CMD_PAGEPROG, 0);
> +
> +	pl353_nand_write_data_op(mtd, buf,
> +				 (mtd->oobsize -
> +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> +	buf += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_write_data_op(mtd, buf, PL353_NAND_LAST_TRANSFER_LENGTH);
> +	nand_wait_ready(mtd);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the data buffer
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to read
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_read_page_raw(struct mtd_info *mtd,
> +				    struct nand_chip *chip,
> +				    u8 *buf, int oob_required, int page) {
> +	unsigned long data_phase_addr;
> +	u8 *p;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_nand_read_data_op(chip, buf, mtd->writesize);
> +	p = chip->oob_poi;
> +	pl353_nand_read_data_op(chip, p,
> +				(mtd->oobsize -
> +				PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_write_page_raw - [Intern] raw page write function
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the data buffer
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to write
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_write_page_raw(struct mtd_info *mtd,
> +				     struct nand_chip *chip,
> +				     const u8 *buf, int oob_required,
> +				     int page)
> +{
> +	unsigned long data_phase_addr;
> +	u8 *p;
> +
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_nand_write_data_op(mtd, buf, mtd->writesize);
> +	p = chip->oob_poi;
> +	pl353_nand_write_data_op(mtd, p,
> +				 (mtd->oobsize -
> +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	return 0;
> +}
> +
> +/**
> + * nand_write_page_hwecc - Hardware ECC based page write function
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the data buffer
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to write
> + *
> + * This functions writes data and hardware generated ECC values in to the page.
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
> +				       struct nand_chip *chip,
> +				       const u8 *buf, int oob_required,
> +				       int page)
> +{
> +	int eccsize = chip->ecc.size;
> +	int eccsteps = chip->ecc.steps;
> +	u8 *ecc_calc = chip->ecc.calc_buf;
> +	u8 *oob_ptr;
> +	const u8 *p = buf;
> +	u32 ret;
> +	unsigned long data_phase_addr;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_SEQIN,
> +			  NAND_CMD_PAGEPROG, 0);
> +
> +	for ( ; (eccsteps - 1); eccsteps--) {
> +		pl353_nand_write_data_op(mtd, p, eccsize);
> +		p += eccsize;
> +	}
> +	pl353_nand_write_data_op(mtd, p,
> +				 (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	/* Set ECC Last bit to 1 */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	p = buf;
> +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> +
> +	/* Wait for ECC to be calculated and read the error values */
> +	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi,
> +					 0, chip->ecc.total);
> +	if (ret)
> +		return ret;
> +	/* Clear ECC last bit */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	/* Write the spare area with ECC bytes */
> +	oob_ptr = chip->oob_poi;
> +	pl353_nand_write_data_op(mtd, oob_ptr,
> +				 (mtd->oobsize -
> +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +	pl353_nand_write_data_op(mtd, oob_ptr,
> PL353_NAND_LAST_TRANSFER_LENGTH);
> +	nand_wait_ready(mtd);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_read_page_hwecc - Hardware ECC based page read function
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the buffer to store read data
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to read
> + *
> + * This functions reads data and checks the data integrity by comparing
> + * hardware generated ECC values and read ECC values from spare area.
> + * There is a limitation in SMC controller, that we must set ECC LAST
> +on
> + * last data phase access, to tell ECC block not to expect any data further.
> + * Ex:  When number of ECC STEPS are 4, then till 3 we will write to
> +flash
> + * using SMC with HW ECC enabled. And for the last ECC STEP, we will
> +subtract
> + * 4bytes from page size, and will initiate a transfer. And the
> +remaining 4 as
> + * one more transfer with ECC_LAST bit set in NAND data phase register
> +to
> + * notify ECC block not to expect any more data. The last block should
> +be align
> + * with end of 512 byte block. Because of this limitation, we are not
> +using
> + * core routines.
> + *
> + * Return:	0 always and updates ECC operation status in to MTD structure
> + */
> +static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
> +				      struct nand_chip *chip,
> +				      u8 *buf, int oob_required, int page) {
> +	int i, stat, eccsize = chip->ecc.size;
> +	int eccbytes = chip->ecc.bytes;
> +	int eccsteps = chip->ecc.steps;
> +	u8 *p = buf;
> +	u8 *ecc_calc = chip->ecc.calc_buf;
> +	u8 *ecc = chip->ecc.code_buf;
> +	unsigned int max_bitflips = 0;
> +	u8 *oob_ptr;
> +	u32 ret;
> +	unsigned long data_phase_addr;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_READ0,
> +			  NAND_CMD_READSTART, 1);
> +	nand_wait_ready(mtd);
> +
> +	for ( ; (eccsteps - 1); eccsteps--) {
> +		pl353_nand_read_data_op(chip, p, eccsize);
> +		p += eccsize;
> +	}
> +	pl353_nand_read_data_op(chip, p,
> +				(eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	/* Set ECC Last bit to 1 */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	/* Read the calculated ECC value */
> +	p = buf;
> +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> +
> +	/* Clear ECC last bit */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	/* Read the stored ECC value */
> +	oob_ptr = chip->oob_poi;
> +	pl353_nand_read_data_op(chip, oob_ptr,
> +				(mtd->oobsize -
> +				PL353_NAND_LAST_TRANSFER_LENGTH));
> +
> +	/* de-assert chip select */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +	pl353_nand_read_data_op(chip, oob_ptr,
> +PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	ret = mtd_ooblayout_get_eccbytes(mtd, ecc, chip->oob_poi, 0,
> +					 chip->ecc.total);
> +	if (ret)
> +		return ret;
> +
> +	eccsteps = chip->ecc.steps;
> +	p = buf;
> +
> +	/* Check ECC error for all blocks and correct if it is correctable */
> +	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
> +		stat = chip->ecc.correct(mtd, p, &ecc[i], &ecc_calc[i]);
> +		if (stat < 0) {
> +			mtd->ecc_stats.failed++;
> +		} else {
> +			mtd->ecc_stats.corrected += stat;
> +			max_bitflips = max_t(unsigned int, max_bitflips, stat);
> +		}
> +	}
> +
> +	return max_bitflips;
> +}
> +
> +/**
> + * pl353_nand_select_chip - Select the flash device
> + * @mtd:	Pointer to the mtd info structure
> + * @chip:	Pointer to the NAND chip info structure
> + *
> + * This function is empty as the NAND controller handles chip select
> +line
> + * internally based on the chip address passed in command and data phase.
> + */
> +static void pl353_nand_select_chip(struct mtd_info *mtd, int chip) { }
> +
> +/* NAND framework ->exec_op() hooks and related helpers */ static void
> +pl353_nfc_parse_instructions(struct nand_chip *chip,
> +					 const struct nand_subop *subop,
> +					 struct pl353_nfc_op *nfc_op)
> +{
> +	const struct nand_op_instr *instr = NULL;
> +	unsigned int op_id, offset, naddrs;
> +	int i, len;
> +	const u8 *addrs;
> +
> +	memset(nfc_op, 0, sizeof(struct pl353_nfc_op));
> +	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> +		nfc_op->len = nand_subop_get_data_len(subop, op_id);
> +		len = nand_subop_get_data_len(subop, op_id);
> +		instr = &subop->instrs[op_id];
> +
> +		switch (instr->type) {
> +		case NAND_OP_CMD_INSTR:
> +			nfc_op->type = NAND_OP_CMD_INSTR;
> +			if (op_id)
> +				nfc_op->cmnds[1] = instr->ctx.cmd.opcode;
> +			else
> +				nfc_op->cmnds[0] = instr->ctx.cmd.opcode;
> +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> +			break;
> +
> +		case NAND_OP_ADDR_INSTR:
> +			offset = nand_subop_get_addr_start_off(subop, op_id);
> +			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> +			addrs = &instr->ctx.addr.addrs[offset];
> +			nfc_op->addrs = instr->ctx.addr.addrs[offset];
> +			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) {
> +				nfc_op->addrs |= instr->ctx.addr.addrs[i] <<
> +						 (8 * i);
> +			}
> +
> +			if (naddrs >= 5)
> +				nfc_op->addr5 = addrs[4];
> +			if (naddrs >= 6)
> +				nfc_op->addr6 = addrs[5];
> +			nfc_op->naddrs = nand_subop_get_num_addr_cyc(subop,
> +								     op_id);
> +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> +			break;
> +
> +		case NAND_OP_DATA_IN_INSTR:
> +			nfc_op->data_instr = instr;
> +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> +			nfc_op->data_instr_idx = op_id;
> +			break;
> +
> +		case NAND_OP_DATA_OUT_INSTR:
> +			nfc_op->data_instr = instr;
> +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> +			nfc_op->data_instr_idx = op_id;
> +			break;
> +
> +		case NAND_OP_WAITRDY_INSTR:
> +			nfc_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
> +			nfc_op->rdy_delay_ns = instr->delay_ns;
> +			break;
> +		}
> +	}
> +}
> +
> +static void cond_delay(unsigned int ns) {
> +	if (!ns)
> +		return;
> +
> +	if (ns < 10000)
> +		ndelay(ns);
> +	else
> +		udelay(DIV_ROUND_UP(ns, 1000));
> +}
> +
> +/**
> + * pl353_nand_cmd_function - Send command to NAND device
> + * @chip:	Pointer to the NAND chip info structure
> + * @subop:	Pointer to array of instructions
> + * Return:	Always return zero
> + */
> +static int pl353_nand_cmd_function(struct nand_chip *chip,
> +				   const struct nand_subop *subop)
> +{
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +	const struct nand_op_instr *instr;
> +	struct pl353_nfc_op nfc_op = {};
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long cmd_data = 0, end_cmd_valid = 0;
> +	unsigned long cmd_phase_addr, data_phase_addr, end_cmd;
> +	unsigned int op_id, len, offset;
> +	bool reading;
> +
> +	pl353_nfc_parse_instructions(chip, subop, &nfc_op);
> +	instr = nfc_op.data_instr;
> +	op_id = nfc_op.data_instr_idx;
> +	len = nand_subop_get_data_len(subop, op_id);
> +	offset = nand_subop_get_data_start_off(subop, op_id);
> +
> +	pl353_smc_clr_nand_int();
> +	/* Get the command phase address */
> +	if (nfc_op.cmnds[1] != 0) {
> +		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN)
> +			end_cmd_valid = 0;
> +		else
> +			end_cmd_valid = 1;
> +		end_cmd = nfc_op.cmnds[1];
> +	}  else {
> +		end_cmd = 0x0;
> +	}
> +
> +	/*
> +	 * The SMC defines two phases of commands when transferring data to or
> +	 * from NAND flash.
> +	 * Command phase: Commands and optional address information are written
> +	 * to the NAND flash.The command and address can be associated with
> +	 * either a data phase operation to write to or read from the array,
> +	 * or a status/ID register transfer.
> +	 * Data phase: Data is either written to or read from the NAND flash.
> +	 * This data can be either data transferred to or from the array,
> +	 * or status/ID register information.
> +	 */
> +	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
> +			 ((nfc_op.naddrs << ADDR_CYCLES_SHIFT) |
> +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> +			 (COMMAND_PHASE) |
> +			 (end_cmd << END_CMD_SHIFT) |
> +			 (nfc_op.cmnds[0] << START_CMD_SHIFT));
> +
> +	/* Get the data phase address */
> +	end_cmd_valid = 0;
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nand_base +
> +			  ((0x0 << CLEAR_CS_SHIFT) |
> +			  (end_cmd_valid << END_CMD_VALID_SHIFT) |
> +			  (DATA_PHASE) |
> +			  (end_cmd << END_CMD_SHIFT) |
> +			  (0x0 << ECC_LAST_SHIFT));
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	/* Command phase AXI Read & Write */
> +	if (nfc_op.naddrs >= 5) {
> +		if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> +			cmd_data = nfc_op.addrs;
> +			/* Another address cycle for devices > 128MiB */
> +			if (chip->options & NAND_ROW_ADDR_3) {
> +				writel_relaxed(cmd_data,
> +					       (void __iomem * __force)
> +					       cmd_phase_addr);
> +				cmd_data = nfc_op.addr5;
> +				if (nfc_op.naddrs >= 6)
> +					cmd_data |= (nfc_op.addr6 << 8);
> +			}
> +		}
> +	}  else {
> +		if (nfc_op.addrs != -1) {
> +			int column = nfc_op.addrs;
> +			/*
> +			 * Change read/write column, read id etc
> +			 * Adjust columns for 16 bit bus width
> +			 */
> +			if ((chip->options & NAND_BUSWIDTH_16) &&
> +			    (nfc_op.cmnds[0] == NAND_CMD_READ0 ||
> +				nfc_op.cmnds[0] == NAND_CMD_SEQIN ||
> +				nfc_op.cmnds[0] == NAND_CMD_RNDOUT ||
> +				nfc_op.cmnds[0] == NAND_CMD_RNDIN)) {
> +				column >>= 1;
> +			}
> +			cmd_data = column;
> +		}
> +	}
> +	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr);
> +
> +	if (!nfc_op.data_instr) {
> +		if (nfc_op.rdy_timeout_ms)
> +			nand_wait_ready(mtd);
> +		return 0;
> +	}
> +
> +	reading = (nfc_op.data_instr->type == NAND_OP_DATA_IN_INSTR);
> +	if (!reading) {
> +		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN &&
> +		    nfc_op.cmnds[1] == NAND_CMD_PAGEPROG) {
> +			pl353_nand_write_page_raw(mtd, chip,
> +						  instr->ctx.data.buf.out, 0,
> +						  nfc_op.addrs);
> +
> +		} else {
> +			pl353_nand_write_data_op(mtd, instr->ctx.data.buf.out,
> +						 len);
> +		}
> +		if (nfc_op.rdy_timeout_ms)
> +			nand_wait_ready(mtd);
> +		cond_delay(nfc_op.rdy_delay_ns);
> +	}
> +	if (reading) {
> +		cond_delay(nfc_op.rdy_delay_ns);
> +		if (nfc_op.rdy_timeout_ms)
> +			nand_wait_ready(mtd);
> +		pl353_nand_read_data_op(chip, instr->ctx.data.buf.in, len);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct nand_op_parser pl353_nfc_op_parser = NAND_OP_PARSER
> +	(NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 7),
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false),
> +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 8),
> +		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 2048),
> +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false)),
> +	);
> +
> +static int pl353_nfc_exec_op(struct nand_chip *chip,
> +			     const struct nand_operation *op,
> +			     bool check_only)
> +{
> +	return nand_op_parser_exec_op(chip, &pl353_nfc_op_parser,
> +					      op, check_only);
> +}
> +
> +/**
> + * pl353_nand_device_ready - Check device ready/busy line
> + * @mtd:	Pointer to the mtd_info structure
> + *
> + * Return:	0 on busy or 1 on ready state
> + */
> +static int pl353_nand_device_ready(struct mtd_info *mtd) {
> +	if (pl353_smc_get_nand_int_status_raw()) {
> +		pl353_smc_clr_nand_int();
> +		return 1;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
> + * @mtd:	Pointer to the mtd_info structure
> + * @ecc:	Pointer to ECC control structure
> + * @ecc_mode:	ondie ecc status
> + *
> + * This function initializes the ecc block and functional pointers as
> +per the
> + * ecc mode
> + *
> + * Return:	0 on success or negative errno.
> + */
> +static int pl353_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
> +				int ecc_mode)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	int err = 0;
> +
> +	if (ecc_mode == NAND_ECC_ON_DIE) {
> +		pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
> +		/*
> +		 * On-Die ECC spare bytes offset 8 is used for ECC codes
> +		 * Use the BBT pattern descriptors
> +		 */
> +		chip->bbt_td = &bbt_main_descr;
> +		chip->bbt_md = &bbt_mirror_descr;
> +		bitmap_set(chip->parameters.get_feature_list,
> +			   ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> +		bitmap_set(chip->parameters.set_feature_list,
> +			   ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> +	} else {
> +		ecc->read_oob = pl353_nand_read_oob;
> +		ecc->write_oob = pl353_nand_write_oob;
> +
> +		ecc->mode = NAND_ECC_HW;
> +		/* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
> +		ecc->bytes = 3;
> +		ecc->strength = 1;
> +		ecc->calculate = pl353_nand_calculate_hwecc;
> +		ecc->correct = pl353_nand_correct_data;
> +		ecc->read_page = pl353_nand_read_page_hwecc;
> +		ecc->size = PL353_NAND_ECC_SIZE;
> +		ecc->write_page = pl353_nand_write_page_hwecc;
> +		pl353_smc_set_ecc_pg_size(mtd->writesize);
> +		switch (mtd->writesize) {
> +		case SZ_512:
> +		case SZ_1K:
> +		case SZ_2K:
> +			pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_APB);
> +			break;
> +		default:
> +			ecc->calculate = nand_calculate_ecc;
> +			ecc->correct = nand_correct_data;
> +			ecc->size = 256;
> +			break;
> +		}
> +		if (mtd->writesize <= SZ_512)
> +			xnfc->addr_cycles = 1;
> +		else
> +			xnfc->addr_cycles = 2;
> +
> +		if (chip->options & NAND_ROW_ADDR_3)
> +			xnfc->addr_cycles += 3;
> +		else
> +			xnfc->addr_cycles += 2;
> +
> +		if (mtd->oobsize == 16) {
> +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout16_ops);
> +		} else if (mtd->oobsize == 64) {
> +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout64_ops);
> +		} else {
> +			err = -ENXIO;
> +			dev_err(xnfc->dev, "Unsupported oob Layout\n");
> +		}
> +	}
> +	return err;
> +}
> +
> +static int pl353_setup_data_interface(struct mtd_info *mtd, int csline,
> +				       const struct nand_data_interface *conf) {
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	const struct nand_sdr_timings *sdr;
> +	u32 timings[7], mckperiodps;
> +
> +	sdr = nand_get_sdr_timings(conf);
> +	if (IS_ERR(sdr))
> +		return PTR_ERR(sdr);
> +
> +	/*
> +	 * SDR timings are given in pico-seconds while NFC timings must be
> +	 * expressed in NAND controller clock cycles.
> +	 */
> +	mckperiodps = NSEC_PER_SEC / clk_get_rate(xnfc->mclk);
> +	mckperiodps *= 1000;
> +	if (sdr->tRC_min <= 20000)
> +		/*
> +		 * PL353 SMC needs one extra read cycle in SDR Mode 5
> +		 * This is not written anywhere in the datasheet but
> +		 * the results observed during testing.
> +		 */
> +		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps) + 1;
> +	else
> +		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps);
> +
> +	timings[1] = DIV_ROUND_UP(sdr->tWC_min, mckperiodps);
> +	/*
> +	 * For all SDR modes, PL353 SMC needs tREA max value as 1
> +	 * These results observed during testing.
> +	 */
> +	timings[2] = PL353_TREA_MAX_VALUE;
> +	timings[3] = DIV_ROUND_UP(sdr->tWP_min, mckperiodps);
> +	timings[4] = DIV_ROUND_UP(sdr->tCLR_min, mckperiodps);
> +	timings[5] = DIV_ROUND_UP(sdr->tAR_min, mckperiodps);
> +	timings[6] = DIV_ROUND_UP(sdr->tRR_min, mckperiodps);
> +
> +	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
> +		return 0;
> +
> +	pl353_smc_set_cycles(timings);
> +
> +	return 0;
> +}
> +/**
> + * pl353_nand_probe - Probe method for the NAND driver
> + * @pdev:	Pointer to the platform_device structure
> + *
> + * This function initializes the driver data structures and the hardware.
> + * The NAND driver has dependency with the pl353_smc memory controller
> + * driver for initializing the NAND timing parameters, bus width, ECC
> +modes,
> + * control and status information.
> + *
> + * Return:	0 on success or error value on failure
> + */
> +static int pl353_nand_probe(struct platform_device *pdev) {
> +	struct pl353_nand_info *xnfc;
> +	struct mtd_info *mtd;
> +	struct nand_chip *chip;
> +	struct resource *res;
> +	struct device_node *np;
> +	u32 ret;
> +
> +	xnfc = devm_kzalloc(&pdev->dev, sizeof(*xnfc), GFP_KERNEL);
> +	if (!xnfc)
> +		return -ENOMEM;
> +	xnfc->dev = &pdev->dev;
> +	/* Map physical address of NAND flash */
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	xnfc->nand_base = devm_ioremap_resource(xnfc->dev, res);
> +	if (IS_ERR(xnfc->nand_base))
> +		return PTR_ERR(xnfc->nand_base);
> +
> +	chip = &xnfc->chip;
> +	mtd = nand_to_mtd(chip);
> +	chip->exec_op = pl353_nfc_exec_op;
> +	nand_set_controller_data(chip, xnfc);
> +	mtd->priv = chip;
> +	mtd->owner = THIS_MODULE;
> +	if (!mtd->name) {
> +		/*
> +		 * If the new bindings are used and the bootloader has not been
> +		 * updated to pass a new mtdparts parameter on the cmdline, you
> +		 * should define the following property in your NAND node, ie:
> +		 *
> +		 *	label = "pl353-nand";
> +		 *
> +		 * This way, mtd->name will be set by the core when
> +		 * nand_set_flash_node() is called.
> +		 */
> +		mtd->name = devm_kasprintf(xnfc->dev, GFP_KERNEL,
> +					   "%s", PL353_NAND_DRIVER_NAME);
> +		if (!mtd->name) {
> +			dev_err(xnfc->dev, "Failed to allocate mtd->name\n");
> +			return -ENOMEM;
> +		}
> +	}
> +	nand_set_flash_node(chip, xnfc->dev->of_node);
> +
> +	/* Set the driver entry points for MTD */
> +	chip->dev_ready = pl353_nand_device_ready;
> +	chip->select_chip = pl353_nand_select_chip;
> +	/* If we don't set this delay driver sets 20us by default */
> +	np = of_get_next_parent(xnfc->dev->of_node);
> +	xnfc->mclk = of_clk_get(np, 0);
> +	if (IS_ERR(xnfc->mclk)) {
> +		dev_err(xnfc->dev, "Failed to retrieve MCK clk\n");
> +		return PTR_ERR(xnfc->mclk);
> +	}
> +	chip->chip_delay = 30;
> +	/* Set the device option and flash width */
> +	chip->options = NAND_BUSWIDTH_AUTO;
> +	chip->bbt_options = NAND_BBT_USE_FLASH;
> +	platform_set_drvdata(pdev, xnfc);
> +	chip->setup_data_interface = pl353_setup_data_interface;
> +	/* first scan to find the device and get the page size */
> +	if (nand_scan_ident(mtd, 1, NULL)) {
> +		dev_err(xnfc->dev, "nand_scan_ident for NAND failed\n");
> +		return -ENXIO;
> +	}
> +	ret = pl353_nand_ecc_init(mtd, &chip->ecc, chip->ecc.mode);
> +	if (chip->options & NAND_BUSWIDTH_16)
> +		pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_16);
> +	/* second phase scan */
> +	if (nand_scan_tail(mtd)) {
> +		dev_err(xnfc->dev, "nand_scan_tail for NAND failed\n");
> +		return -ENXIO;
> +	}
> +
> +	ret = mtd_device_register(mtd, NULL, 0);
> +	if (ret) {
> +		dev_err(xnfc->dev, "Failed to register mtd device: %d\n", ret);
> +		nand_cleanup(chip);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_remove - Remove method for the NAND driver
> + * @pdev:	Pointer to the platform_device structure
> + *
> + * This function is called if the driver module is being unloaded. It
> +frees all
> + * resources allocated to the device.
> + *
> + * Return:	0 on success or error value on failure
> + */
> +static int pl353_nand_remove(struct platform_device *pdev) {
> +	struct pl353_nand_info *xnfc = platform_get_drvdata(pdev);
> +	struct mtd_info *mtd = nand_to_mtd(&xnfc->chip);
> +
> +	/* Release resources, unregister device */
> +	nand_release(mtd);
> +
> +	return 0;
> +}
> +
> +/* Match table for device tree binding */ static const struct
> +of_device_id pl353_nand_of_match[] = {
> +	{ .compatible = "arm,pl353-nand-r2p1" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, pl353_nand_of_match);
> +
> +/*
> + * pl353_nand_driver - This structure defines the NAND subsystem
> +platform driver  */ static struct platform_driver pl353_nand_driver = {
> +	.probe		= pl353_nand_probe,
> +	.remove		= pl353_nand_remove,
> +	.driver		= {
> +		.name	= PL353_NAND_DRIVER_NAME,
> +		.of_match_table = pl353_nand_of_match,
> +	},
> +};
> +
> +module_platform_driver(pl353_nand_driver);
> +
> +MODULE_AUTHOR("Xilinx, Inc.");
> +MODULE_ALIAS("platform:" PL353_NAND_DRIVER_NAME);
> +MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
> +MODULE_LICENSE("GPL");
> --
> 2.7.4

Re: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

[Miquel Raynal]

Hi Naga,

Naga Sureshkumar Relli <nagasure@xilinx.com> wrote on Sun, 22 Jul 2018
07:04:41 +0000:

> Hi Miquel,
> 
> Could you please provide your review comments?
> I will address if any.

We are almost at the end of a pretty big release, I ran out of time to
do another review of your series, sorry for the delay.

Regards,
Miquèl

RE: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

[Naga Sureshkumar Relli]

Hi Miquel,

> -----Original Message-----
> From: Miquel Raynal [mailto:miquel.raynal@bootlin.com]
> Sent: Monday, July 23, 2018 1:01 PM
> To: Naga Sureshkumar Relli <nagasure@xilinx.com>
> Cc: boris.brezillon@bootlin.com; richard@nod.at; dwmw2@infradead.org;
> computersforpeace@gmail.com; marek.vasut@gmail.com; f.fainelli@gmail.com;
> mmayer@broadcom.com; rogerq@ti.com; ladis@linux-mips.org; ada@thorsis.co;
> honghui.zhang@mediatek.com; linus.walleij@linaro.org; linux-mtd@lists.infradead.org; linux-
> kernel@vger.kernel.org; nagasureshkumarrelli@gmail.com; Michal Simek
> <michals@xilinx.com>
> Subject: Re: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353
> smc nand interface
> 
> Hi Naga,
> 
> Naga Sureshkumar Relli <nagasure@xilinx.com> wrote on Sun, 22 Jul 2018
> 07:04:41 +0000:
> 
> > Hi Miquel,
> >
> > Could you please provide your review comments?
> > I will address if any.
> 
> We are almost at the end of a pretty big release, I ran out of time to do another review of your
> series, sorry for the delay.
No problem, and thanks for your reply.

Thanks,
Naga Sureshkumar Relli
> 
> Regards,
> Miquèl

Re: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

[Miquel Raynal]

Hi Naga,

Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> wrote on
Wed, 11 Jul 2018 13:06:52 +0530:

> Add driver for arm pl353 static memory controller nand interface with HW ECC
> support. This controller is used in Xilinx Zynq SoC for interfacing the NAND
> flash memory.
> 
> Signed-off-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
> ---
> Changes in v11:
>  - Removed Documentation patch and added the required info in driver as
>    per Boris comments.
>  - Removed unwanted variables from pl353_nand_info as per Miquel comments
>  - Removed IO_ADDR_R/W.
>  - Replaced onhot() with hweight32()
>  - Defined macros for static values in function pl353_nand_correct_data()
>  - Removed all unnecessary delays
>  - Used nand_wait_ready() where ever is required
>  - Modifed the pl353_setup_data_interface() logic as per Miquel comments.
>  - Taken array instead of 7 values in pl353_setup_data_interface() and pass
>    it to smc driver.
>  - Added check to collect the return value of mtd_device_register().
> Changes in 10:
>  - Typos correction like nand to NAND and soc to SOC etc..
>  - Defined macros for the values in pl353_nand_calculate_hwecc()
>  - Modifed ecc_status from int to char in pl353_nand_calculate_hwecc()
>  - Changed the return type form int to bool to the function
>    onehot()
>  - Removed udelay(1000) in pl353_cmd_function, as it is not required
>  - Dropped ecc->hwctl = NULL in pl353_ecc_init()
>  - Added an error message in pl353_ecc_init(), when there is no matching
>    oobsize
>  - Changed the variable from xnand to xnfc
>  - Added logic to get mtd->name from DT, if it is specified in DT
> Changes in v9:
>  - Addressed the below comments given by Miquel
>  - instead of using pl353_nand_write32, use directly writel_relaxed
>  - Fixed check patch warnings
>  - Renamed write_buf/read_buf to write_data_op/read_data_op
>  - use BIT macro instead of 1 << nr
>  - Use NAND_ROW_ADDR_3 flag
>  - Use nand_wait_ready()
>  - Removed swecc functions
>  - Use address cycles as per size, instead of reading it from Parameter page
>  - Instead of writing too many patterns, use optional property
> Changes in v8:
>  - Added exec_op() implementation
>  - Fixed the below v7 review comments
>  - removed mtd_info from pl353_nand_info struct
>  - Corrected ecc layout offsets
>  - Added on-die ecc support
> Changes in v7:
>  - Currently not implemented the memclk rate adjustments. I will
>    look into this later and once the basic driver is accepted.
>  - Fixed GPL licence ident
> Changes in v6:
>  - Fixed the checkpatch.pl reported warnings
>  - Using the address cycles information from the onfi param page
>    earlier it is hardcoded to 5 in driver
> Changes in v5:
>  - Configure the nand timing parameters as per the onfi spec Changes in v4:
>  - Updated the driver to sync with pl353_smc driver APIs
> Changes in v3:
>  - implemented the proper error codes
>  - further breakdown this patch to multiple sets
>  - added the controller and driver details to Documentation section
>  - updated the licenece to GPLv2
>  - reorganized the pl353_nand_ecc_init function
> Changes in v2:
>  - use "depends on" rather than "select" option in kconfig
>  - remove unused variable parts
> ---
>  drivers/mtd/nand/raw/Kconfig      |    7 +
>  drivers/mtd/nand/raw/Makefile     |    1 +
>  drivers/mtd/nand/raw/pl353_nand.c | 1314 +++++++++++++++++++++++++++++++++++++
>  3 files changed, 1322 insertions(+)
>  create mode 100644 drivers/mtd/nand/raw/pl353_nand.c
> 
> diff --git a/drivers/mtd/nand/raw/Kconfig b/drivers/mtd/nand/raw/Kconfig
> index 6871ff0..1c5d528 100644
> --- a/drivers/mtd/nand/raw/Kconfig
> +++ b/drivers/mtd/nand/raw/Kconfig
> @@ -530,4 +530,11 @@ config MTD_NAND_MTK
>  	  Enables support for NAND controller on MTK SoCs.
>  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
>  
> +config MTD_NAND_PL353
> +	tristate "ARM Pl353 NAND flash driver"
> +	depends on MTD_NAND && ARM
> +	depends on PL353_SMC
> +	help
> +	  Enables support for PrimeCell Static Memory Controller PL353.
> +
>  endif # MTD_NAND
> diff --git a/drivers/mtd/nand/raw/Makefile b/drivers/mtd/nand/raw/Makefile
> index 165b7ef..1c702e1 100644
> --- a/drivers/mtd/nand/raw/Makefile
> +++ b/drivers/mtd/nand/raw/Makefile
> @@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        += hisi504_nand.o
>  obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
>  obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
>  obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
> +obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o
>  
>  nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
>  nand-objs += nand_amd.o
> diff --git a/drivers/mtd/nand/raw/pl353_nand.c b/drivers/mtd/nand/raw/pl353_nand.c
> new file mode 100644
> index 0000000..3fa9ba07
> --- /dev/null
> +++ b/drivers/mtd/nand/raw/pl353_nand.c
> @@ -0,0 +1,1314 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ARM PL353 NAND flash controller driver
> + *
> + * Copyright (C) 2017 Xilinx, Inc
> + * Author: Punnaiah chowdary kalluri <punnaiah@xilinx.com>
> + * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
> + *
> + */
> +
> +#include <linux/err.h>
> +#include <linux/delay.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/irq.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/mtd/mtd.h>
> +#include <linux/mtd/rawnand.h>
> +#include <linux/mtd/nand_ecc.h>
> +#include <linux/mtd/partitions.h>
> +#include <linux/of_address.h>
> +#include <linux/of_device.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/slab.h>
> +#include <linux/pl353-smc.h>
> +#include <linux/clk.h>
> +
> +#define PL353_NAND_DRIVER_NAME "pl353-nand"
> +
> +/* NAND flash driver defines */
> +#define PL353_NAND_CMD_PHASE	1	/* End command valid in command phase */
> +#define PL353_NAND_DATA_PHASE	2	/* End command valid in data phase */
> +#define PL353_NAND_ECC_SIZE	512	/* Size of data for ECC operation */
> +
> +/* Flash memory controller operating parameters */
> +
> +#define PL353_NAND_ECC_CONFIG	(BIT(4)  |	/* ECC read at end of page */ \
> +				 (0 << 5))	/* No Jumping */
> +
> +/* AXI Address definitions */
> +#define START_CMD_SHIFT		3
> +#define END_CMD_SHIFT		11
> +#define END_CMD_VALID_SHIFT	20
> +#define ADDR_CYCLES_SHIFT	21
> +#define CLEAR_CS_SHIFT		21
> +#define ECC_LAST_SHIFT		10
> +#define COMMAND_PHASE		(0 << 19)
> +#define DATA_PHASE		BIT(19)
> +
> +#define PL353_NAND_ECC_LAST	BIT(ECC_LAST_SHIFT)	/* Set ECC_Last */
> +#define PL353_NAND_CLEAR_CS	BIT(CLEAR_CS_SHIFT)	/* Clear chip select */
> +
> +#define ONDIE_ECC_FEATURE_ADDR	0x90
> +#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
> +#define PL353_NAND_DEV_BUSY_TIMEOUT	(1 * HZ)
> +#define PL353_NAND_LAST_TRANSFER_LENGTH	4
> +#define PL353_NAND_ECC_VALID_SHIFT	24
> +#define PL353_NAND_ECC_VALID_MASK	0x40
> +#define PL353_ECC_BITS_BYTEOFF_MASK	0x1FF
> +#define PL353_ECC_BITS_BITOFF_MASK	0x7
> +#define PL353_ECC_BIT_MASK		0xFFF
> +#define PL353_TREA_MAX_VALUE		1
> +
> +struct pl353_nfc_op {
> +	u32 cmnds[4];
> +	u32 thirdrow;
> +	u32 type;
> +	u32 end_cmd;
> +	u32 addrs;
> +	u32 len;
> +	u32 naddrs;
> +	u32 addr5;
> +	u32 addr6;
> +	unsigned int data_instr_idx;
> +	unsigned int rdy_timeout_ms;
> +	unsigned int rdy_delay_ns;
> +	unsigned int cle_ale_delay_ns;
> +	const struct nand_op_instr *data_instr;
> +};
> +
> +/**
> + * struct pl353_nand_info - Defines the NAND flash driver instance

I suppose you mean "NAND flash controller driver instance", in this
case, pl353_nand_info could be pl353_nand_controller?

> + * @chip:		NAND chip information structure
> + * @dev:		Parent device (used to print error messages)
> + * @nand_base:		Virtual address of the NAND flash device
> + * @nandaddr:		Virtual address of the NAND flash device for
> + *			data read/writes
> + * @addr_cycles:	Address cycles
> + * @mclk:		Memory controller clock
> + */
> +struct pl353_nand_info {
> +	struct nand_chip chip;
> +	struct device *dev;
> +	void __iomem *nand_base;
> +	void __iomem *nandaddr;

Maybe nand_base and nandaddr are not very descriptive names. What
about 'regs' intead of nand_base? And if nandaddr is a buffer
address, what about "buf_addr"?

> +	u8 addr_cycles;
> +	struct clk *mclk;
> +};
> +
> +static int pl353_ecc_ooblayout16_ecc(struct mtd_info *mtd, int section,
> +				     struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes);
> +	oobregion->length = chip->ecc.bytes;
> +
> +	return 0;
> +}
> +
> +static int pl353_ecc_ooblayout16_free(struct mtd_info *mtd, int section,
> +				      struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes) + 8;
> +	oobregion->length = 8;
> +
> +	return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout16_ops = {
> +	.ecc = pl353_ecc_ooblayout16_ecc,
> +	.free = pl353_ecc_ooblayout16_free,
> +};
> +
> +static int pl353_ecc_ooblayout64_ecc(struct mtd_info *mtd, int section,
> +				     struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes) + 52;
> +	oobregion->length = chip->ecc.bytes;
> +
> +	return 0;
> +}
> +
> +static int pl353_ecc_ooblayout64_free(struct mtd_info *mtd, int section,
> +				      struct mtd_oob_region *oobregion)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +
> +	if (section)
> +		return -ERANGE;
> +
> +	if (section >= chip->ecc.steps)
> +		return -ERANGE;
> +
> +	oobregion->offset = (section * chip->ecc.bytes) + 2;
> +	oobregion->length = 50;
> +
> +	return 0;
> +}
> +
> +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout64_ops = {
> +	.ecc = pl353_ecc_ooblayout64_ecc,
> +	.free = pl353_ecc_ooblayout64_free,
> +};
> +
> +/* Generic flash bbt decriptors */
> +static u8 bbt_pattern[] = { 'B', 'b', 't', '0' };
> +static u8 mirror_pattern[] = { '1', 't', 'b', 'B' };
> +
> +static struct nand_bbt_descr bbt_main_descr = {
> +	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
> +		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> +	.offs = 4,
> +	.len = 4,
> +	.veroffs = 20,
> +	.maxblocks = 4,
> +	.pattern = bbt_pattern
> +};
> +
> +static struct nand_bbt_descr bbt_mirror_descr = {
> +	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
> +		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> +	.offs = 4,
> +	.len = 4,
> +	.veroffs = 20,
> +	.maxblocks = 4,
> +	.pattern = mirror_pattern
> +};
> +
> +/**
> + * pl353_nand_read_data_op - read chip data into buffer
> + * @chip:	Pointer to the NAND chip info structure
> + * @in:		Pointer to the buffer to store read data
> + * @len:	Number of bytes to read
> + * Return:	Always return zero
> + */
> +static int pl353_nand_read_data_op(struct nand_chip *chip,
> +				   u8 *in,
> +				   unsigned int len)
> +{
> +	int i;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +
> +	if (IS_ALIGNED((uint32_t)in, sizeof(uint32_t)) &&
> +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> +		u32 *ptr = (u32 *)in;
> +
> +		len /= 4;
> +		for (i = 0; i < len; i++)
> +			ptr[i] = readl(xnfc->nandaddr);
> +	} else {
> +		for (i = 0; i < len; i++)
> +			in[i] = readb(xnfc->nandaddr);
> +	}

What about reading 0-3 bytes with readb if the driver is not aligned,
then doing aligned access with readl until readb must be used again for
the last 0-3 bytes?

> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_write_buf - write buffer to chip
> + * @mtd:	Pointer to the mtd info structure
> + * @buf:	Pointer to the buffer to store write data
> + * @len:	Number of bytes to write
> + */
> +static void pl353_nand_write_data_op(struct mtd_info *mtd, const u8 *buf,
> +				     int len)
> +{
> +	int i;
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +
> +	if (IS_ALIGNED((uint32_t)buf, sizeof(uint32_t)) &&
> +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> +		u32 *ptr = (u32 *)buf;
> +
> +		len /= 4;
> +		for (i = 0; i < len; i++)
> +			writel(ptr[i], xnfc->nandaddr);
> +	} else {
> +		for (i = 0; i < len; i++)
> +			writeb(buf[i], xnfc->nandaddr);
> +	}

Ditto.

> +}
> +
> +/**
> + * pl353_nand_calculate_hwecc - Calculate Hardware ECC
> + * @mtd:	Pointer to the mtd_info structure
> + * @data:	Pointer to the page data
> + * @ecc:	Pointer to the ECC buffer where ECC data needs to be stored
> + *
> + * This function retrieves the Hardware ECC data from the controller and returns
> + * ECC data back to the MTD subsystem.
> + * It operates on a number of 512 byte blocks of NAND memory and can be
> + * programmed to store the ECC codes after the data in memory. For writes,
> + * the ECC is written to the spare area of the page. For reads, the result of
> + * a block ECC check are made available to the device driver.
> + *
> + * ------------------------------------------------------------------------
> + * |               n * 512 blocks                  | extra  | ecc    |     |
> + * |                                               | block  | codes  |     |
> + * ------------------------------------------------------------------------
> + *
> + * The ECC calculation uses a simple Hamming code, using 1-bit correction 2-bit
> + * detection. It starts when a valid read or write command with a 512 byte
> + * aligned address is detected on the memory interface.
> + *
> + * Return:	0 on success or error value on failure
> + */
> +static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
> +				      const u8 *data, u8 *ecc)
> +{
> +	u32 ecc_value;
> +	u8 ecc_reg, ecc_byte, ecc_status;
> +	unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
> +
> +	/* Wait till the ECC operation is complete or timeout */
> +	do {
> +		if (pl353_smc_ecc_is_busy())
> +			cpu_relax();
> +		else
> +			break;
> +	} while (!time_after_eq(jiffies, timeout));
> +
> +	if (time_after_eq(jiffies, timeout)) {
> +		pr_err("%s timed out\n", __func__);
> +		return -ETIMEDOUT;
> +	}

All of this should be done by the function calling
nand_calculate_hwecc(), not here.

Plus, it should deserve a function on its own.

> +
> +	for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
> +		/* Read ECC value for each block */

So you assume here that there are 4, and only 4 "blocks" (I prefer
"ECC chunks" or "subpages"). Is it always the case? Or is it just how
it works in your situation? I would rather prefer a to define this
value anyway.

> +		ecc_value = pl353_smc_get_ecc_val(ecc_reg);
> +		ecc_status = (ecc_value >> PL353_NAND_ECC_VALID_SHIFT);

Space

> +		/* ECC value valid */
> +		if (ecc_status & PL353_NAND_ECC_VALID_MASK) {
> +			for (ecc_byte = 0; ecc_byte < 3; ecc_byte++) {

Define 3

> +				/* Copy ECC bytes to MTD buffer */
> +				*ecc = ~ecc_value & 0xFF;
> +				ecc_value = ecc_value >> 8;
> +				ecc++;
> +			}
> +		} else {
> +			pr_warn("%s status failed\n", __func__);
> +			return -1;
> +		}
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_correct_data - ECC correction function
> + * @mtd:	Pointer to the mtd_info structure
> + * @buf:	Pointer to the page data
> + * @read_ecc:	Pointer to the ECC value read from spare data area
> + * @calc_ecc:	Pointer to the calculated ECC value
> + *
> + * This function corrects the ECC single bit errors & detects 2-bit errors.
> + *
> + * Return:	0 if no ECC errors found
> + *		1 if single bit error found and corrected.
> + *		-1 if multiple uncorrectable ECC errors found.
> + */
> +static int pl353_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
> +				   unsigned char *read_ecc,
> +				   unsigned char *calc_ecc)
> +{
> +	unsigned char bit_addr;
> +	unsigned int byte_addr;
> +	unsigned short ecc_odd, ecc_even, read_ecc_lower, read_ecc_upper;
> +	unsigned short calc_ecc_lower, calc_ecc_upper;
> +
> +	read_ecc_lower = (read_ecc[0] | (read_ecc[1] << 8)) &
> +			  PL353_ECC_BIT_MASK;
> +	read_ecc_upper = ((read_ecc[1] >> 4) | (read_ecc[2] << 4)) &
> +			  PL353_ECC_BIT_MASK;
> +
> +	calc_ecc_lower = (calc_ecc[0] | (calc_ecc[1] << 8)) &
> +			  PL353_ECC_BIT_MASK;
> +	calc_ecc_upper = ((calc_ecc[1] >> 4) | (calc_ecc[2] << 4)) &
> +			  PL353_ECC_BIT_MASK;
> +
> +	ecc_odd = read_ecc_lower ^ calc_ecc_lower;
> +	ecc_even = read_ecc_upper ^ calc_ecc_upper;
> +
> +	/* no error */
> +	if (!ecc_odd && !ecc_even)
> +		return 0;
> +
> +	if (ecc_odd == (~ecc_even & PL353_ECC_BIT_MASK)) {
> +		/* bits [11:3] of error code is byte offset */
> +		byte_addr = (ecc_odd >> 3) & PL353_ECC_BITS_BYTEOFF_MASK;
> +		/* bits [2:0] of error code is bit offset */
> +		bit_addr = ecc_odd & PL353_ECC_BITS_BITOFF_MASK;
> +		/* Toggling error bit */
> +		buf[byte_addr] ^= (BIT(bit_addr));
> +		return 1;
> +	}
> +
> +	/* one error in parity */
> +	if (hweight32(ecc_odd | ecc_even) == 1)
> +		return 1;
> +
> +	/* Uncorrectable error */
> +	return -1;
> +}
> +
> +static void pl353_prepare_cmd(struct mtd_info *mtd, struct nand_chip *chip,
> +			      int page, int column, int start_cmd, int end_cmd,
> +			      bool read)
> +{
> +	unsigned long data_phase_addr;
> +	u32 end_cmd_valid = 0;
> +	unsigned long cmd_phase_addr = 0, cmd_data = 0;
> +
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +
> +	end_cmd_valid = read ? 1 : 0;
> +
> +	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +

do you really need this cast?

> +			 ((xnfc->addr_cycles
> +			 << ADDR_CYCLES_SHIFT) |
> +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> +			 (COMMAND_PHASE) |
> +			 (end_cmd << END_CMD_SHIFT) |
> +			 (start_cmd << START_CMD_SHIFT));

So the number of address cycles changes the address where you should
write the address cycles? that's weird, no?

> +
> +	/* Get the data phase address */
> +	data_phase_addr = (unsigned long __force)xnfc->nand_base +
> +			  ((0x0 << CLEAR_CS_SHIFT) |
> +			  (0 << END_CMD_VALID_SHIFT) |
> +			  (DATA_PHASE) |
> +			  (end_cmd << END_CMD_SHIFT) |
> +			  (0x0 << ECC_LAST_SHIFT));
> +
Same question here?

> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;

This should be done only once in the probe

> +
> +	if (chip->options & NAND_BUSWIDTH_16)
> +		column /= 2;
> +	cmd_data = column;

Please rename cmd_data because assigning a column (ie, an address
cycle) to a variable name "cmd_data" is weird.

> +	if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> +		cmd_data |= page << 16;
> +		/* Another address cycle for devices > 128MiB */
> +		if (chip->options & NAND_ROW_ADDR_3) {
> +			writel_relaxed(cmd_data,
> +				       (void __iomem * __force)cmd_phase_addr);
> +			cmd_data = (page >> 16);
> +		}
> +	} else {
> +		cmd_data |= page << 8;
> +	}
> +
> +	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr);
> +}
> +
> +/**
> + * pl353_nand_read_oob - [REPLACEABLE] the most common OOB data read function
> + * @mtd:	Pointer to the mtd info structure 

NAND and MTD are always upper case in plain english. Here I suppose you
refer to the structure name, the use the exact name "mtd_info".


> + * @chip:	Pointer to the NAND chip info structure
> + * @page:	Page number to read
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
> +			       int page)
> +{
> +	unsigned long data_phase_addr;
> +	u8 *p;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	chip->pagebuf = -1;
> +	if (mtd->writesize < PL353_NAND_ECC_SIZE)
> +		return 0;
> +
> +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_READ0,
> +			  NAND_CMD_READSTART, 1);
> +
> +	nand_wait_ready(mtd);
> +
> +	p = chip->oob_poi;
> +	pl353_nand_read_data_op(chip, p,
> +				(mtd->oobsize -
> +				PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr += nand_offset;

This is still a foreign language for me, why do you do the math
everytime? And please explain what's done here, it's absolutely not
clear for me.

> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;

You should not need the cast.

> +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_write_oob - [REPLACEABLE] the most common OOB data write function
> + * @mtd:	Pointer to the mtd info structure
> + * @chip:	Pointer to the NAND chip info structure
> + * @page:	Page number to write
> + *
> + * Return:	Zero on success and EIO on failure
> + */
> +static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
> +				int page)
> +{
> +	const u8 *buf = chip->oob_poi;
> +	unsigned long data_phase_addr;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +	u32 addrcycles = 0;
> +
> +	chip->pagebuf = -1;
> +	addrcycles = xnfc->addr_cycles;
> +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_SEQIN,
> +			  NAND_CMD_PAGEPROG, 0);
> +
> +	pl353_nand_write_data_op(mtd, buf,
> +				 (mtd->oobsize -
> +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> +	buf += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_write_data_op(mtd, buf, PL353_NAND_LAST_TRANSFER_LENGTH);
> +	nand_wait_ready(mtd);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the data buffer
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to read
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_read_page_raw(struct mtd_info *mtd,
> +				    struct nand_chip *chip,
> +				    u8 *buf, int oob_required, int page)
> +{
> +	unsigned long data_phase_addr;
> +	u8 *p;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_nand_read_data_op(chip, buf, mtd->writesize);
> +	p = chip->oob_poi;
> +	pl353_nand_read_data_op(chip, p,
> +				(mtd->oobsize -
> +				PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_write_page_raw - [Intern] raw page write function
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the data buffer
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to write
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_write_page_raw(struct mtd_info *mtd,
> +				     struct nand_chip *chip,
> +				     const u8 *buf, int oob_required,
> +				     int page)
> +{
> +	unsigned long data_phase_addr;
> +	u8 *p;
> +
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_nand_write_data_op(mtd, buf, mtd->writesize);
> +	p = chip->oob_poi;
> +	pl353_nand_write_data_op(mtd, p,
> +				 (mtd->oobsize -
> +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	return 0;
> +}
> +
> +/**
> + * nand_write_page_hwecc - Hardware ECC based page write function
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the data buffer
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to write
> + *
> + * This functions writes data and hardware generated ECC values in to the page.
> + *
> + * Return:	Always return zero
> + */
> +static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
> +				       struct nand_chip *chip,
> +				       const u8 *buf, int oob_required,
> +				       int page)
> +{
> +	int eccsize = chip->ecc.size;
> +	int eccsteps = chip->ecc.steps;
> +	u8 *ecc_calc = chip->ecc.calc_buf;
> +	u8 *oob_ptr;
> +	const u8 *p = buf;
> +	u32 ret;
> +	unsigned long data_phase_addr;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_SEQIN,
> +			  NAND_CMD_PAGEPROG, 0);
> +
> +	for ( ; (eccsteps - 1); eccsteps--) {
> +		pl353_nand_write_data_op(mtd, p, eccsize);
> +		p += eccsize;
> +	}
> +	pl353_nand_write_data_op(mtd, p,
> +				 (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	/* Set ECC Last bit to 1 */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	p = buf;
> +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);

You should check the returned value?

> +
> +	/* Wait for ECC to be calculated and read the error values */
> +	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi,
> +					 0, chip->ecc.total);
> +	if (ret)
> +		return ret;
> +	/* Clear ECC last bit */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	/* Write the spare area with ECC bytes */
> +	oob_ptr = chip->oob_poi;
> +	pl353_nand_write_data_op(mtd, oob_ptr,
> +				 (mtd->oobsize -
> +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +	pl353_nand_write_data_op(mtd, oob_ptr, PL353_NAND_LAST_TRANSFER_LENGTH);
> +	nand_wait_ready(mtd);
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_read_page_hwecc - Hardware ECC based page read function
> + * @mtd:		Pointer to the mtd info structure
> + * @chip:		Pointer to the NAND chip info structure
> + * @buf:		Pointer to the buffer to store read data
> + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> + * @page:		Page number to read
> + *
> + * This functions reads data and checks the data integrity by comparing
> + * hardware generated ECC values and read ECC values from spare area.
> + * There is a limitation in SMC controller, that we must set ECC LAST on
> + * last data phase access, to tell ECC block not to expect any data further.
> + * Ex:  When number of ECC STEPS are 4, then till 3 we will write to flash
> + * using SMC with HW ECC enabled. And for the last ECC STEP, we will subtract
> + * 4bytes from page size, and will initiate a transfer. And the remaining 4 as
> + * one more transfer with ECC_LAST bit set in NAND data phase register to
> + * notify ECC block not to expect any more data. The last block should be align
> + * with end of 512 byte block. Because of this limitation, we are not using
> + * core routines.
> + *
> + * Return:	0 always and updates ECC operation status in to MTD structure
> + */
> +static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
> +				      struct nand_chip *chip,
> +				      u8 *buf, int oob_required, int page)
> +{
> +	int i, stat, eccsize = chip->ecc.size;
> +	int eccbytes = chip->ecc.bytes;
> +	int eccsteps = chip->ecc.steps;
> +	u8 *p = buf;
> +	u8 *ecc_calc = chip->ecc.calc_buf;
> +	u8 *ecc = chip->ecc.code_buf;
> +	unsigned int max_bitflips = 0;
> +	u8 *oob_ptr;
> +	u32 ret;
> +	unsigned long data_phase_addr;
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> +
> +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_READ0,
> +			  NAND_CMD_READSTART, 1);
> +	nand_wait_ready(mtd);
> +
> +	for ( ; (eccsteps - 1); eccsteps--) {
> +		pl353_nand_read_data_op(chip, p, eccsize);
> +		p += eccsize;
> +	}
> +	pl353_nand_read_data_op(chip, p,
> +				(eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	/* Set ECC Last bit to 1 */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	/* Read the calculated ECC value */
> +	p = buf;
> +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> +

You should check the returned value?

> +	/* Clear ECC last bit */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	/* Read the stored ECC value */
> +	oob_ptr = chip->oob_poi;
> +	pl353_nand_read_data_op(chip, oob_ptr,
> +				(mtd->oobsize -
> +				PL353_NAND_LAST_TRANSFER_LENGTH));
> +
> +	/* de-assert chip select */
> +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> +	data_phase_addr -= nand_offset;
> +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> +	data_phase_addr += nand_offset;
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> +	pl353_nand_read_data_op(chip, oob_ptr, PL353_NAND_LAST_TRANSFER_LENGTH);
> +
> +	ret = mtd_ooblayout_get_eccbytes(mtd, ecc, chip->oob_poi, 0,
> +					 chip->ecc.total);
> +	if (ret)
> +		return ret;
> +
> +	eccsteps = chip->ecc.steps;
> +	p = buf;
> +
> +	/* Check ECC error for all blocks and correct if it is correctable */
> +	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
> +		stat = chip->ecc.correct(mtd, p, &ecc[i], &ecc_calc[i]);
> +		if (stat < 0) {
> +			mtd->ecc_stats.failed++;
> +		} else {
> +			mtd->ecc_stats.corrected += stat;
> +			max_bitflips = max_t(unsigned int, max_bitflips, stat);
> +		}
> +	}
> +
> +	return max_bitflips;
> +}
> +
> +/**
> + * pl353_nand_select_chip - Select the flash device
> + * @mtd:	Pointer to the mtd info structure
> + * @chip:	Pointer to the NAND chip info structure
> + *
> + * This function is empty as the NAND controller handles chip select line
> + * internally based on the chip address passed in command and data phase.
> + */
> +static void pl353_nand_select_chip(struct mtd_info *mtd, int chip)
> +{
> +}
> +
> +/* NAND framework ->exec_op() hooks and related helpers */
> +static void pl353_nfc_parse_instructions(struct nand_chip *chip,
> +					 const struct nand_subop *subop,
> +					 struct pl353_nfc_op *nfc_op)
> +{
> +	const struct nand_op_instr *instr = NULL;
> +	unsigned int op_id, offset, naddrs;
> +	int i, len;
> +	const u8 *addrs;
> +
> +	memset(nfc_op, 0, sizeof(struct pl353_nfc_op));
> +	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> +		nfc_op->len = nand_subop_get_data_len(subop, op_id);
> +		len = nand_subop_get_data_len(subop, op_id);
> +		instr = &subop->instrs[op_id];
> +
> +		switch (instr->type) {
> +		case NAND_OP_CMD_INSTR:
> +			nfc_op->type = NAND_OP_CMD_INSTR;
> +			if (op_id)
> +				nfc_op->cmnds[1] = instr->ctx.cmd.opcode;
> +			else
> +				nfc_op->cmnds[0] = instr->ctx.cmd.opcode;
> +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> +			break;
> +
> +		case NAND_OP_ADDR_INSTR:
> +			offset = nand_subop_get_addr_start_off(subop, op_id);
> +			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> +			addrs = &instr->ctx.addr.addrs[offset];
> +			nfc_op->addrs = instr->ctx.addr.addrs[offset];
> +			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) {
> +				nfc_op->addrs |= instr->ctx.addr.addrs[i] <<
> +						 (8 * i);
> +			}
> +
> +			if (naddrs >= 5)
> +				nfc_op->addr5 = addrs[4];
> +			if (naddrs >= 6)
> +				nfc_op->addr6 = addrs[5];
> +			nfc_op->naddrs = nand_subop_get_num_addr_cyc(subop,
> +								     op_id);
> +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> +			break;
> +
> +		case NAND_OP_DATA_IN_INSTR:
> +			nfc_op->data_instr = instr;
> +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> +			nfc_op->data_instr_idx = op_id;
> +			break;
> +
> +		case NAND_OP_DATA_OUT_INSTR:
> +			nfc_op->data_instr = instr;
> +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> +			nfc_op->data_instr_idx = op_id;
> +			break;
> +
> +		case NAND_OP_WAITRDY_INSTR:
> +			nfc_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
> +			nfc_op->rdy_delay_ns = instr->delay_ns;
> +			break;
> +		}
> +	}
> +}
> +
> +static void cond_delay(unsigned int ns)
> +{
> +	if (!ns)
> +		return;
> +
> +	if (ns < 10000)
> +		ndelay(ns);
> +	else
> +		udelay(DIV_ROUND_UP(ns, 1000));
> +}
> +
> +/**
> + * pl353_nand_cmd_function - Send command to NAND device
> + * @chip:	Pointer to the NAND chip info structure
> + * @subop:	Pointer to array of instructions
> + * Return:	Always return zero
> + */
> +static int pl353_nand_cmd_function(struct nand_chip *chip,
> +				   const struct nand_subop *subop)

Please don't use this name, too close from the cmdfunc() hook we are
trying to remove.

> +{
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +	const struct nand_op_instr *instr;
> +	struct pl353_nfc_op nfc_op = {};
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	unsigned long cmd_data = 0, end_cmd_valid = 0;
> +	unsigned long cmd_phase_addr, data_phase_addr, end_cmd;
> +	unsigned int op_id, len, offset;
> +	bool reading;
> +
> +	pl353_nfc_parse_instructions(chip, subop, &nfc_op);
> +	instr = nfc_op.data_instr;
> +	op_id = nfc_op.data_instr_idx;
> +	len = nand_subop_get_data_len(subop, op_id);
> +	offset = nand_subop_get_data_start_off(subop, op_id);
> +
> +	pl353_smc_clr_nand_int();
> +	/* Get the command phase address */
> +	if (nfc_op.cmnds[1] != 0) {
> +		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN)
> +			end_cmd_valid = 0;
> +		else
> +			end_cmd_valid = 1;
> +		end_cmd = nfc_op.cmnds[1];
> +	}  else {
> +		end_cmd = 0x0;
> +	}
> +
> +	/*
> +	 * The SMC defines two phases of commands when transferring data to or
> +	 * from NAND flash.
> +	 * Command phase: Commands and optional address information are written
> +	 * to the NAND flash.The command and address can be associated with
> +	 * either a data phase operation to write to or read from the array,
> +	 * or a status/ID register transfer.
> +	 * Data phase: Data is either written to or read from the NAND flash.
> +	 * This data can be either data transferred to or from the array,
> +	 * or status/ID register information.
> +	 */
> +	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
> +			 ((nfc_op.naddrs << ADDR_CYCLES_SHIFT) |
> +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> +			 (COMMAND_PHASE) |
> +			 (end_cmd << END_CMD_SHIFT) |
> +			 (nfc_op.cmnds[0] << START_CMD_SHIFT));
> +
> +	/* Get the data phase address */
> +	end_cmd_valid = 0;
> +
> +	data_phase_addr = (unsigned long __force)xnfc->nand_base +
> +			  ((0x0 << CLEAR_CS_SHIFT) |
> +			  (end_cmd_valid << END_CMD_VALID_SHIFT) |
> +			  (DATA_PHASE) |
> +			  (end_cmd << END_CMD_SHIFT) |
> +			  (0x0 << ECC_LAST_SHIFT));
> +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> +
> +	/* Command phase AXI Read & Write */
> +	if (nfc_op.naddrs >= 5) {
> +		if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> +			cmd_data = nfc_op.addrs;
> +			/* Another address cycle for devices > 128MiB */
> +			if (chip->options & NAND_ROW_ADDR_3) {
> +				writel_relaxed(cmd_data,
> +					       (void __iomem * __force)
> +					       cmd_phase_addr);
> +				cmd_data = nfc_op.addr5;
> +				if (nfc_op.naddrs >= 6)
> +					cmd_data |= (nfc_op.addr6 << 8);
> +			}
> +		}
> +	}  else {
> +		if (nfc_op.addrs != -1) {
> +			int column = nfc_op.addrs;
> +			/*
> +			 * Change read/write column, read id etc
> +			 * Adjust columns for 16 bit bus width
> +			 */
> +			if ((chip->options & NAND_BUSWIDTH_16) &&
> +			    (nfc_op.cmnds[0] == NAND_CMD_READ0 ||
> +				nfc_op.cmnds[0] == NAND_CMD_SEQIN ||
> +				nfc_op.cmnds[0] == NAND_CMD_RNDOUT ||
> +				nfc_op.cmnds[0] == NAND_CMD_RNDIN)) {
> +				column >>= 1;
> +			}
> +			cmd_data = column;
> +		}
> +	}
> +	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr);
> +
> +	if (!nfc_op.data_instr) {
> +		if (nfc_op.rdy_timeout_ms)
> +			nand_wait_ready(mtd);
> +		return 0;
> +	}
> +
> +	reading = (nfc_op.data_instr->type == NAND_OP_DATA_IN_INSTR);
> +	if (!reading) {
> +		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN &&
> +		    nfc_op.cmnds[1] == NAND_CMD_PAGEPROG) {
> +			pl353_nand_write_page_raw(mtd, chip,
> +						  instr->ctx.data.buf.out, 0,
> +						  nfc_op.addrs);
> +
> +		} else {
> +			pl353_nand_write_data_op(mtd, instr->ctx.data.buf.out,
> +						 len);
> +		}
> +		if (nfc_op.rdy_timeout_ms)
> +			nand_wait_ready(mtd);
> +		cond_delay(nfc_op.rdy_delay_ns);
> +	}
> +	if (reading) {
> +		cond_delay(nfc_op.rdy_delay_ns);
> +		if (nfc_op.rdy_timeout_ms)
> +			nand_wait_ready(mtd);
> +		pl353_nand_read_data_op(chip, instr->ctx.data.buf.in, len);
> +	}
> +
> +	return 0;
> +}
> +
> +static const struct nand_op_parser pl353_nfc_op_parser = NAND_OP_PARSER
> +	(NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 7),
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false),
> +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 8),
> +		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 2048),
> +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
> +	NAND_OP_PARSER_PATTERN
> +		(pl353_nand_cmd_function,
> +		NAND_OP_PARSER_PAT_CMD_ELEM(false)),
> +	);
> +
> +static int pl353_nfc_exec_op(struct nand_chip *chip,
> +			     const struct nand_operation *op,
> +			     bool check_only)
> +{
> +	return nand_op_parser_exec_op(chip, &pl353_nfc_op_parser,
> +					      op, check_only);
> +}
> +
> +/**
> + * pl353_nand_device_ready - Check device ready/busy line
> + * @mtd:	Pointer to the mtd_info structure
> + *
> + * Return:	0 on busy or 1 on ready state
> + */
> +static int pl353_nand_device_ready(struct mtd_info *mtd
> +{
> +	if (pl353_smc_get_nand_int_status_raw()) {
> +		pl353_smc_clr_nand_int();
> +		return 1;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
> + * @mtd:	Pointer to the mtd_info structure
> + * @ecc:	Pointer to ECC control structure
> + * @ecc_mode:	ondie ecc status
> + *
> + * This function initializes the ecc block and functional pointers as per the
> + * ecc mode
> + *
> + * Return:	0 on success or negative errno.
> + */
> +static int pl353_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
> +				int ecc_mode)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	int err = 0;
> +
> +	if (ecc_mode == NAND_ECC_ON_DIE) {
> +		pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
> +		/*
> +		 * On-Die ECC spare bytes offset 8 is used for ECC codes
> +		 * Use the BBT pattern descriptors
> +		 */
> +		chip->bbt_td = &bbt_main_descr;
> +		chip->bbt_md = &bbt_mirror_descr;
> +		bitmap_set(chip->parameters.get_feature_list,
> +			   ONFI_FEATURE_ON_DIE_ECC, ONFI_FEATURE_ON_DIE_ECC_EN);
> +		bitmap_set(chip->parameters.set_feature_list,
> +			   ONFI_FEATURE_ON_DIE_ECC, ONFI_FEATURE_ON_DIE_ECC_EN);
> +	} else {
> +		ecc->read_oob = pl353_nand_read_oob;
> +		ecc->write_oob = pl353_nand_write_oob;
> +
> +		ecc->mode = NAND_ECC_HW;
> +		/* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
> +		ecc->bytes = 3;
> +		ecc->strength = 1;
> +		ecc->calculate = pl353_nand_calculate_hwecc;
> +		ecc->correct = pl353_nand_correct_data;
> +		ecc->read_page = pl353_nand_read_page_hwecc;
> +		ecc->size = PL353_NAND_ECC_SIZE;
> +		ecc->write_page = pl353_nand_write_page_hwecc;
> +		pl353_smc_set_ecc_pg_size(mtd->writesize);
> +		switch (mtd->writesize) {
> +		case SZ_512:
> +		case SZ_1K:
> +		case SZ_2K:
> +			pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_APB);
> +			break;
> +		default:
> +			ecc->calculate = nand_calculate_ecc;
> +			ecc->correct = nand_correct_data;
> +			ecc->size = 256;
> +			break;
> +		}
> +		if (mtd->writesize <= SZ_512)
> +			xnfc->addr_cycles = 1;
> +		else
> +			xnfc->addr_cycles = 2;
> +
> +		if (chip->options & NAND_ROW_ADDR_3)
> +			xnfc->addr_cycles += 3;
> +		else
> +			xnfc->addr_cycles += 2;
> +
> +		if (mtd->oobsize == 16) {
> +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout16_ops);
> +		} else if (mtd->oobsize == 64) {
> +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout64_ops);
> +		} else {
> +			err = -ENXIO;
> +			dev_err(xnfc->dev, "Unsupported oob Layout\n");
> +		}
> +	}
> +	return err;
> +}
> +
> +static int pl353_setup_data_interface(struct mtd_info *mtd, int csline,
> +				       const struct nand_data_interface *conf)
> +{
> +	struct nand_chip *chip = mtd_to_nand(mtd);
> +	struct pl353_nand_info *xnfc =
> +		container_of(chip, struct pl353_nand_info, chip);
> +	const struct nand_sdr_timings *sdr;
> +	u32 timings[7], mckperiodps;
> +
> +	sdr = nand_get_sdr_timings(conf);
> +	if (IS_ERR(sdr))
> +		return PTR_ERR(sdr);
> +
> +	/*
> +	 * SDR timings are given in pico-seconds while NFC timings must be
> +	 * expressed in NAND controller clock cycles.
> +	 */
> +	mckperiodps = NSEC_PER_SEC / clk_get_rate(xnfc->mclk);
> +	mckperiodps *= 1000;
> +	if (sdr->tRC_min <= 20000)
> +		/*
> +		 * PL353 SMC needs one extra read cycle in SDR Mode 5
> +		 * This is not written anywhere in the datasheet but
> +		 * the results observed during testing.

Oh, that's bad.

> +		 */
> +		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps) + 1;
> +	else
> +		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps);
> +
> +	timings[1] = DIV_ROUND_UP(sdr->tWC_min, mckperiodps);
> +	/*
> +	 * For all SDR modes, PL353 SMC needs tREA max value as 1
> +	 * These results observed during testing.

s/These results/Results/

> +	 */
> +	timings[2] = PL353_TREA_MAX_VALUE;
> +	timings[3] = DIV_ROUND_UP(sdr->tWP_min, mckperiodps);
> +	timings[4] = DIV_ROUND_UP(sdr->tCLR_min, mckperiodps);
> +	timings[5] = DIV_ROUND_UP(sdr->tAR_min, mckperiodps);
> +	timings[6] = DIV_ROUND_UP(sdr->tRR_min, mckperiodps);
> +
> +	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
> +		return 0;

You should move this to the top.

> +
> +	pl353_smc_set_cycles(timings);
> +
> +	return 0;
> +}
> +/**
> + * pl353_nand_probe - Probe method for the NAND driver
> + * @pdev:	Pointer to the platform_device structure
> + *
> + * This function initializes the driver data structures and the hardware.
> + * The NAND driver has dependency with the pl353_smc memory controller
> + * driver for initializing the NAND timing parameters, bus width, ECC modes,
> + * control and status information.
> + *
> + * Return:	0 on success or error value on failure
> + */
> +static int pl353_nand_probe(struct platform_device *pdev)
> +{
> +	struct pl353_nand_info *xnfc;
> +	struct mtd_info *mtd;
> +	struct nand_chip *chip;
> +	struct resource *res;
> +	struct device_node *np;
> +	u32 ret;
> +
> +	xnfc = devm_kzalloc(&pdev->dev, sizeof(*xnfc), GFP_KERNEL);
> +	if (!xnfc)
> +		return -ENOMEM;
> +	xnfc->dev = &pdev->dev;
> +	/* Map physical address of NAND flash */
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	xnfc->nand_base = devm_ioremap_resource(xnfc->dev, res);
> +	if (IS_ERR(xnfc->nand_base))
> +		return PTR_ERR(xnfc->nand_base);
> +
> +	chip = &xnfc->chip;
> +	mtd = nand_to_mtd(chip);
> +	chip->exec_op = pl353_nfc_exec_op;
> +	nand_set_controller_data(chip, xnfc);
> +	mtd->priv = chip;
> +	mtd->owner = THIS_MODULE;
> +	if (!mtd->name) {
> +		/*
> +		 * If the new bindings are used and the bootloader has not been
> +		 * updated to pass a new mtdparts parameter on the cmdline, you
> +		 * should define the following property in your NAND node, ie:
> +		 *
> +		 *	label = "pl353-nand";
> +		 *
> +		 * This way, mtd->name will be set by the core when
> +		 * nand_set_flash_node() is called.
> +		 */
> +		mtd->name = devm_kasprintf(xnfc->dev, GFP_KERNEL,
> +					   "%s", PL353_NAND_DRIVER_NAME);
> +		if (!mtd->name) {
> +			dev_err(xnfc->dev, "Failed to allocate mtd->name\n");
> +			return -ENOMEM;
> +		}
> +	}
> +	nand_set_flash_node(chip, xnfc->dev->of_node);
> +
> +	/* Set the driver entry points for MTD */
> +	chip->dev_ready = pl353_nand_device_ready;
> +	chip->select_chip = pl353_nand_select_chip;
> +	/* If we don't set this delay driver sets 20us by default */
> +	np = of_get_next_parent(xnfc->dev->of_node);
> +	xnfc->mclk = of_clk_get(np, 0);
> +	if (IS_ERR(xnfc->mclk)) {
> +		dev_err(xnfc->dev, "Failed to retrieve MCK clk\n");
> +		return PTR_ERR(xnfc->mclk);
> +	}
> +	chip->chip_delay = 30;
> +	/* Set the device option and flash width */
> +	chip->options = NAND_BUSWIDTH_AUTO;
> +	chip->bbt_options = NAND_BBT_USE_FLASH;
> +	platform_set_drvdata(pdev, xnfc);
> +	chip->setup_data_interface = pl353_setup_data_interface;
> +	/* first scan to find the device and get the page size */
> +	if (nand_scan_ident(mtd, 1, NULL)) {
> +		dev_err(xnfc->dev, "nand_scan_ident for NAND failed\n");
> +		return -ENXIO;
> +	}
> +	ret = pl353_nand_ecc_init(mtd, &chip->ecc, chip->ecc.mode);
> +	if (chip->options & NAND_BUSWIDTH_16)
> +		pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_16);
> +	/* second phase scan */
> +	if (nand_scan_tail(mtd)) {
> +		dev_err(xnfc->dev, "nand_scan_tail for NAND failed\n");
> +		return -ENXIO;
> +	}
> +

I suggest you to wait for v4.19-rc1 to be out and then rebase on top
of it as this cycle we changed a lot of things.

Particularly, nand_scan_ident() and nand_scan_tail() are not
exposed anymore, you should create nand_controller_ops with an
->attach_chip() hook that does everything between ident() and tail()
and use nand_scan() instead.

> +	ret = mtd_device_register(mtd, NULL, 0);
> +	if (ret) {
> +		dev_err(xnfc->dev, "Failed to register mtd device: %d\n", ret);
> +		nand_cleanup(chip);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * pl353_nand_remove - Remove method for the NAND driver
> + * @pdev:	Pointer to the platform_device structure
> + *
> + * This function is called if the driver module is being unloaded. It frees all
> + * resources allocated to the device.
> + *
> + * Return:	0 on success or error value on failure
> + */
> +static int pl353_nand_remove(struct platform_device *pdev)
> +{
> +	struct pl353_nand_info *xnfc = platform_get_drvdata(pdev);
> +	struct mtd_info *mtd = nand_to_mtd(&xnfc->chip);
> +
> +	/* Release resources, unregister device */
> +	nand_release(mtd);
> +
> +	return 0;
> +}
> +
> +/* Match table for device tree binding */
> +static const struct of_device_id pl353_nand_of_match[] = {
> +	{ .compatible = "arm,pl353-nand-r2p1" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, pl353_nand_of_match);
> +
> +/*
> + * pl353_nand_driver - This structure defines the NAND subsystem platform driver
> + */
> +static struct platform_driver pl353_nand_driver = {
> +	.probe		= pl353_nand_probe,
> +	.remove		= pl353_nand_remove,
> +	.driver		= {
> +		.name	= PL353_NAND_DRIVER_NAME,
> +		.of_match_table = pl353_nand_of_match,
> +	},
> +};
> +
> +module_platform_driver(pl353_nand_driver);
> +
> +MODULE_AUTHOR("Xilinx, Inc.");
> +MODULE_ALIAS("platform:" PL353_NAND_DRIVER_NAME);
> +MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
> +MODULE_LICENSE("GPL");


Thanks,
Miquèl

RE: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

[Naga Sureshkumar Relli]

Hi Miquel,

Thanks for the review.

> -----Original Message-----
> From: Miquel Raynal [mailto:miquel.raynal@bootlin.com]
> Sent: Monday, July 30, 2018 12:46 AM
> To: Naga Sureshkumar Relli <nagasure@xilinx.com>
> Cc: boris.brezillon@bootlin.com; richard@nod.at; dwmw2@infradead.org;
> computersforpeace@gmail.com; marek.vasut@gmail.com; f.fainelli@gmail.com;
> mmayer@broadcom.com; rogerq@ti.com; ladis@linux-mips.org; ada@thorsis.co;
> honghui.zhang@mediatek.com; linus.walleij@linaro.org; linux-mtd@lists.infradead.org; linux-
> kernel@vger.kernel.org; nagasureshkumarrelli@gmail.com; Michal Simek
> <michals@xilinx.com>
> Subject: Re: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353
> smc nand interface
> 
> Hi Naga,
> 
> Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com> wrote on Wed, 11 Jul 2018
> 13:06:52 +0530:
> 
> > Add driver for arm pl353 static memory controller nand interface with
> > HW ECC support. This controller is used in Xilinx Zynq SoC for
> > interfacing the NAND flash memory.
> >
> > Signed-off-by: Naga Sureshkumar Relli
> > <naga.sureshkumar.relli@xilinx.com>
> > ---
> > Changes in v11:
> >  - Removed Documentation patch and added the required info in driver as
> >    per Boris comments.
> >  - Removed unwanted variables from pl353_nand_info as per Miquel
> > comments
> >  - Removed IO_ADDR_R/W.
> >  - Replaced onhot() with hweight32()
> >  - Defined macros for static values in function
> > pl353_nand_correct_data()
> >  - Removed all unnecessary delays
> >  - Used nand_wait_ready() where ever is required
> >  - Modifed the pl353_setup_data_interface() logic as per Miquel comments.
> >  - Taken array instead of 7 values in pl353_setup_data_interface() and pass
> >    it to smc driver.
> >  - Added check to collect the return value of mtd_device_register().
> > Changes in 10:
> >  - Typos correction like nand to NAND and soc to SOC etc..
> >  - Defined macros for the values in pl353_nand_calculate_hwecc()
> >  - Modifed ecc_status from int to char in pl353_nand_calculate_hwecc()
> >  - Changed the return type form int to bool to the function
> >    onehot()
> >  - Removed udelay(1000) in pl353_cmd_function, as it is not required
> >  - Dropped ecc->hwctl = NULL in pl353_ecc_init()
> >  - Added an error message in pl353_ecc_init(), when there is no matching
> >    oobsize
> >  - Changed the variable from xnand to xnfc
> >  - Added logic to get mtd->name from DT, if it is specified in DT
> > Changes in v9:
> >  - Addressed the below comments given by Miquel
> >  - instead of using pl353_nand_write32, use directly writel_relaxed
> >  - Fixed check patch warnings
> >  - Renamed write_buf/read_buf to write_data_op/read_data_op
> >  - use BIT macro instead of 1 << nr
> >  - Use NAND_ROW_ADDR_3 flag
> >  - Use nand_wait_ready()
> >  - Removed swecc functions
> >  - Use address cycles as per size, instead of reading it from
> > Parameter page
> >  - Instead of writing too many patterns, use optional property Changes
> > in v8:
> >  - Added exec_op() implementation
> >  - Fixed the below v7 review comments
> >  - removed mtd_info from pl353_nand_info struct
> >  - Corrected ecc layout offsets
> >  - Added on-die ecc support
> > Changes in v7:
> >  - Currently not implemented the memclk rate adjustments. I will
> >    look into this later and once the basic driver is accepted.
> >  - Fixed GPL licence ident
> > Changes in v6:
> >  - Fixed the checkpatch.pl reported warnings
> >  - Using the address cycles information from the onfi param page
> >    earlier it is hardcoded to 5 in driver Changes in v5:
> >  - Configure the nand timing parameters as per the onfi spec Changes in v4:
> >  - Updated the driver to sync with pl353_smc driver APIs Changes in
> > v3:
> >  - implemented the proper error codes
> >  - further breakdown this patch to multiple sets
> >  - added the controller and driver details to Documentation section
> >  - updated the licenece to GPLv2
> >  - reorganized the pl353_nand_ecc_init function Changes in v2:
> >  - use "depends on" rather than "select" option in kconfig
> >  - remove unused variable parts
> > ---
> >  drivers/mtd/nand/raw/Kconfig      |    7 +
> >  drivers/mtd/nand/raw/Makefile     |    1 +
> >  drivers/mtd/nand/raw/pl353_nand.c | 1314
> > +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 1322 insertions(+)
> >  create mode 100644 drivers/mtd/nand/raw/pl353_nand.c
> >
> > diff --git a/drivers/mtd/nand/raw/Kconfig
> > b/drivers/mtd/nand/raw/Kconfig index 6871ff0..1c5d528 100644
> > --- a/drivers/mtd/nand/raw/Kconfig
> > +++ b/drivers/mtd/nand/raw/Kconfig
> > @@ -530,4 +530,11 @@ config MTD_NAND_MTK
> >  	  Enables support for NAND controller on MTK SoCs.
> >  	  This controller is found on mt27xx, mt81xx, mt65xx SoCs.
> >
> > +config MTD_NAND_PL353
> > +	tristate "ARM Pl353 NAND flash driver"
> > +	depends on MTD_NAND && ARM
> > +	depends on PL353_SMC
> > +	help
> > +	  Enables support for PrimeCell Static Memory Controller PL353.
> > +
> >  endif # MTD_NAND
> > diff --git a/drivers/mtd/nand/raw/Makefile
> > b/drivers/mtd/nand/raw/Makefile index 165b7ef..1c702e1 100644
> > --- a/drivers/mtd/nand/raw/Makefile
> > +++ b/drivers/mtd/nand/raw/Makefile
> > @@ -56,6 +56,7 @@ obj-$(CONFIG_MTD_NAND_HISI504)	        +=
> hisi504_nand.o
> >  obj-$(CONFIG_MTD_NAND_BRCMNAND)		+= brcmnand/
> >  obj-$(CONFIG_MTD_NAND_QCOM)		+= qcom_nandc.o
> >  obj-$(CONFIG_MTD_NAND_MTK)		+= mtk_ecc.o mtk_nand.o
> > +obj-$(CONFIG_MTD_NAND_PL353)		+= pl353_nand.o
> >
> >  nand-objs := nand_base.o nand_bbt.o nand_timings.o nand_ids.o
> > nand-objs += nand_amd.o diff --git a/drivers/mtd/nand/raw/pl353_nand.c
> > b/drivers/mtd/nand/raw/pl353_nand.c
> > new file mode 100644
> > index 0000000..3fa9ba07
> > --- /dev/null
> > +++ b/drivers/mtd/nand/raw/pl353_nand.c
> > @@ -0,0 +1,1314 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * ARM PL353 NAND flash controller driver
> > + *
> > + * Copyright (C) 2017 Xilinx, Inc
> > + * Author: Punnaiah chowdary kalluri <punnaiah@xilinx.com>
> > + * Author: Naga Sureshkumar Relli <nagasure@xilinx.com>
> > + *
> > + */
> > +
> > +#include <linux/err.h>
> > +#include <linux/delay.h>
> > +#include <linux/interrupt.h>
> > +#include <linux/io.h>
> > +#include <linux/ioport.h>
> > +#include <linux/irq.h>
> > +#include <linux/module.h>
> > +#include <linux/moduleparam.h>
> > +#include <linux/mtd/mtd.h>
> > +#include <linux/mtd/rawnand.h>
> > +#include <linux/mtd/nand_ecc.h>
> > +#include <linux/mtd/partitions.h>
> > +#include <linux/of_address.h>
> > +#include <linux/of_device.h>
> > +#include <linux/of_platform.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/slab.h>
> > +#include <linux/pl353-smc.h>
> > +#include <linux/clk.h>
> > +
> > +#define PL353_NAND_DRIVER_NAME "pl353-nand"
> > +
> > +/* NAND flash driver defines */
> > +#define PL353_NAND_CMD_PHASE	1	/* End command valid in command
> phase */
> > +#define PL353_NAND_DATA_PHASE	2	/* End command valid in data phase
> */
> > +#define PL353_NAND_ECC_SIZE	512	/* Size of data for ECC operation */
> > +
> > +/* Flash memory controller operating parameters */
> > +
> > +#define PL353_NAND_ECC_CONFIG	(BIT(4)  |	/* ECC read at end of page */
> \
> > +				 (0 << 5))	/* No Jumping */
> > +
> > +/* AXI Address definitions */
> > +#define START_CMD_SHIFT		3
> > +#define END_CMD_SHIFT		11
> > +#define END_CMD_VALID_SHIFT	20
> > +#define ADDR_CYCLES_SHIFT	21
> > +#define CLEAR_CS_SHIFT		21
> > +#define ECC_LAST_SHIFT		10
> > +#define COMMAND_PHASE		(0 << 19)
> > +#define DATA_PHASE		BIT(19)
> > +
> > +#define PL353_NAND_ECC_LAST	BIT(ECC_LAST_SHIFT)	/* Set
> ECC_Last */
> > +#define PL353_NAND_CLEAR_CS	BIT(CLEAR_CS_SHIFT)	/* Clear chip
> select */
> > +
> > +#define ONDIE_ECC_FEATURE_ADDR	0x90
> > +#define PL353_NAND_ECC_BUSY_TIMEOUT	(1 * HZ)
> > +#define PL353_NAND_DEV_BUSY_TIMEOUT	(1 * HZ)
> > +#define PL353_NAND_LAST_TRANSFER_LENGTH	4
> > +#define PL353_NAND_ECC_VALID_SHIFT	24
> > +#define PL353_NAND_ECC_VALID_MASK	0x40
> > +#define PL353_ECC_BITS_BYTEOFF_MASK	0x1FF
> > +#define PL353_ECC_BITS_BITOFF_MASK	0x7
> > +#define PL353_ECC_BIT_MASK		0xFFF
> > +#define PL353_TREA_MAX_VALUE		1
> > +
> > +struct pl353_nfc_op {
> > +	u32 cmnds[4];
> > +	u32 thirdrow;
> > +	u32 type;
> > +	u32 end_cmd;
> > +	u32 addrs;
> > +	u32 len;
> > +	u32 naddrs;
> > +	u32 addr5;
> > +	u32 addr6;
> > +	unsigned int data_instr_idx;
> > +	unsigned int rdy_timeout_ms;
> > +	unsigned int rdy_delay_ns;
> > +	unsigned int cle_ale_delay_ns;
> > +	const struct nand_op_instr *data_instr; };
> > +
> > +/**
> > + * struct pl353_nand_info - Defines the NAND flash driver instance
> 
> I suppose you mean "NAND flash controller driver instance", in this case, pl353_nand_info
> could be pl353_nand_controller?
Yes, I will change pl353_nand_info to pl353_nand_controller.

> 
> > + * @chip:		NAND chip information structure
> > + * @dev:		Parent device (used to print error messages)
> > + * @nand_base:		Virtual address of the NAND flash device
> > + * @nandaddr:		Virtual address of the NAND flash device for
> > + *			data read/writes
> > + * @addr_cycles:	Address cycles
> > + * @mclk:		Memory controller clock
> > + */
> > +struct pl353_nand_info {
> > +	struct nand_chip chip;
> > +	struct device *dev;
> > +	void __iomem *nand_base;
> > +	void __iomem *nandaddr;
> 
> Maybe nand_base and nandaddr are not very descriptive names. What about 'regs' intead of
> nand_base? And if nandaddr is a buffer address, what about "buf_addr"?
Miquel, the nand_base is actual io remapped address, and nandaddr is the address that can be used
During data transfers(i.e command phase and data phase)
It can be found in "Table 2-2 NAND AXI address setup" of 
http://infocenter.arm.com/help/topic/com.arm.doc.ddi0380g/DDI0380G_smc_pl350_series_r2p1_trm.pdf
and yes, I will change the naming's as mentioned above.

> 
> > +	u8 addr_cycles;
> > +	struct clk *mclk;
> > +};
> > +
> > +static int pl353_ecc_ooblayout16_ecc(struct mtd_info *mtd, int section,
> > +				     struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes);
> > +	oobregion->length = chip->ecc.bytes;
> > +
> > +	return 0;
> > +}
> > +
> > +static int pl353_ecc_ooblayout16_free(struct mtd_info *mtd, int section,
> > +				      struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes) + 8;
> > +	oobregion->length = 8;
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout16_ops = {
> > +	.ecc = pl353_ecc_ooblayout16_ecc,
> > +	.free = pl353_ecc_ooblayout16_free,
> > +};
> > +
> > +static int pl353_ecc_ooblayout64_ecc(struct mtd_info *mtd, int section,
> > +				     struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes) + 52;
> > +	oobregion->length = chip->ecc.bytes;
> > +
> > +	return 0;
> > +}
> > +
> > +static int pl353_ecc_ooblayout64_free(struct mtd_info *mtd, int section,
> > +				      struct mtd_oob_region *oobregion) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +
> > +	if (section)
> > +		return -ERANGE;
> > +
> > +	if (section >= chip->ecc.steps)
> > +		return -ERANGE;
> > +
> > +	oobregion->offset = (section * chip->ecc.bytes) + 2;
> > +	oobregion->length = 50;
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct mtd_ooblayout_ops pl353_ecc_ooblayout64_ops = {
> > +	.ecc = pl353_ecc_ooblayout64_ecc,
> > +	.free = pl353_ecc_ooblayout64_free,
> > +};
> > +
> > +/* Generic flash bbt decriptors */
> > +static u8 bbt_pattern[] = { 'B', 'b', 't', '0' }; static u8
> > +mirror_pattern[] = { '1', 't', 'b', 'B' };
> > +
> > +static struct nand_bbt_descr bbt_main_descr = {
> > +	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |
> NAND_BBT_WRITE
> > +		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> > +	.offs = 4,
> > +	.len = 4,
> > +	.veroffs = 20,
> > +	.maxblocks = 4,
> > +	.pattern = bbt_pattern
> > +};
> > +
> > +static struct nand_bbt_descr bbt_mirror_descr = {
> > +	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE |
> NAND_BBT_WRITE
> > +		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
> > +	.offs = 4,
> > +	.len = 4,
> > +	.veroffs = 20,
> > +	.maxblocks = 4,
> > +	.pattern = mirror_pattern
> > +};
> > +
> > +/**
> > + * pl353_nand_read_data_op - read chip data into buffer
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @in:		Pointer to the buffer to store read data
> > + * @len:	Number of bytes to read
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_read_data_op(struct nand_chip *chip,
> > +				   u8 *in,
> > +				   unsigned int len)
> > +{
> > +	int i;
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +
> > +	if (IS_ALIGNED((uint32_t)in, sizeof(uint32_t)) &&
> > +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> > +		u32 *ptr = (u32 *)in;
> > +
> > +		len /= 4;
> > +		for (i = 0; i < len; i++)
> > +			ptr[i] = readl(xnfc->nandaddr);
> > +	} else {
> > +		for (i = 0; i < len; i++)
> > +			in[i] = readb(xnfc->nandaddr);
> > +	}
> 
> What about reading 0-3 bytes with readb if the driver is not aligned, then doing aligned
> access with readl until readb must be used again for the last 0-3 bytes?
The else case is handling that right?

> 
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_buf - write buffer to chip
> > + * @mtd:	Pointer to the mtd info structure
> > + * @buf:	Pointer to the buffer to store write data
> > + * @len:	Number of bytes to write
> > + */
> > +static void pl353_nand_write_data_op(struct mtd_info *mtd, const u8 *buf,
> > +				     int len)
> > +{
> > +	int i;
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +
> > +	if (IS_ALIGNED((uint32_t)buf, sizeof(uint32_t)) &&
> > +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> > +		u32 *ptr = (u32 *)buf;
> > +
> > +		len /= 4;
> > +		for (i = 0; i < len; i++)
> > +			writel(ptr[i], xnfc->nandaddr);
> > +	} else {
> > +		for (i = 0; i < len; i++)
> > +			writeb(buf[i], xnfc->nandaddr);
> > +	}
> 
> Ditto.
> 
> > +}
> > +
> > +/**
> > + * pl353_nand_calculate_hwecc - Calculate Hardware ECC
> > + * @mtd:	Pointer to the mtd_info structure
> > + * @data:	Pointer to the page data
> > + * @ecc:	Pointer to the ECC buffer where ECC data needs to be stored
> > + *
> > + * This function retrieves the Hardware ECC data from the controller
> > +and returns
> > + * ECC data back to the MTD subsystem.
> > + * It operates on a number of 512 byte blocks of NAND memory and can
> > +be
> > + * programmed to store the ECC codes after the data in memory. For
> > +writes,
> > + * the ECC is written to the spare area of the page. For reads, the
> > +result of
> > + * a block ECC check are made available to the device driver.
> > + *
> > + * ------------------------------------------------------------------------
> > + * |               n * 512 blocks                  | extra  | ecc    |     |
> > + * |                                               | block  | codes  |     |
> > + *
> > +---------------------------------------------------------------------
> > +---
> > + *
> > + * The ECC calculation uses a simple Hamming code, using 1-bit
> > +correction 2-bit
> > + * detection. It starts when a valid read or write command with a 512
> > +byte
> > + * aligned address is detected on the memory interface.
> > + *
> > + * Return:	0 on success or error value on failure
> > + */
> > +static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
> > +				      const u8 *data, u8 *ecc)
> > +{
> > +	u32 ecc_value;
> > +	u8 ecc_reg, ecc_byte, ecc_status;
> > +	unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
> > +
> > +	/* Wait till the ECC operation is complete or timeout */
> > +	do {
> > +		if (pl353_smc_ecc_is_busy())
> > +			cpu_relax();
> > +		else
> > +			break;
> > +	} while (!time_after_eq(jiffies, timeout));
> > +
> > +	if (time_after_eq(jiffies, timeout)) {
> > +		pr_err("%s timed out\n", __func__);
> > +		return -ETIMEDOUT;
> > +	}
> 
> All of this should be done by the function calling nand_calculate_hwecc(), not here.
Ok, I will update it.
> 
> Plus, it should deserve a function on its own.
Ok, will add new one.
> 
> > +
> > +	for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
> > +		/* Read ECC value for each block */
> 
> So you assume here that there are 4, and only 4 "blocks" (I prefer "ECC chunks" or
> "subpages"). Is it always the case? Or is it just how it works in your situation? I would rather
> prefer a to define this value anyway.
Sure, I will define a macro as ECC chunks to represent 4.
And there are always 4 ECC registers as per the controller. And there is no assumption here.

> 
> > +		ecc_value = pl353_smc_get_ecc_val(ecc_reg);
> > +		ecc_status = (ecc_value >> PL353_NAND_ECC_VALID_SHIFT);
> 
> Space
Hmm. I will correct it.
> 
> > +		/* ECC value valid */
> > +		if (ecc_status & PL353_NAND_ECC_VALID_MASK) {
> > +			for (ecc_byte = 0; ecc_byte < 3; ecc_byte++) {
> 
> Define 3
Ok, I will update it.
> 
> > +				/* Copy ECC bytes to MTD buffer */
> > +				*ecc = ~ecc_value & 0xFF;
> > +				ecc_value = ecc_value >> 8;
> > +				ecc++;
> > +			}
> > +		} else {
> > +			pr_warn("%s status failed\n", __func__);
> > +			return -1;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_correct_data - ECC correction function
> > + * @mtd:	Pointer to the mtd_info structure
> > + * @buf:	Pointer to the page data
> > + * @read_ecc:	Pointer to the ECC value read from spare data area
> > + * @calc_ecc:	Pointer to the calculated ECC value
> > + *
> > + * This function corrects the ECC single bit errors & detects 2-bit errors.
> > + *
> > + * Return:	0 if no ECC errors found
> > + *		1 if single bit error found and corrected.
> > + *		-1 if multiple uncorrectable ECC errors found.
> > + */
> > +static int pl353_nand_correct_data(struct mtd_info *mtd, unsigned char *buf,
> > +				   unsigned char *read_ecc,
> > +				   unsigned char *calc_ecc)
> > +{
> > +	unsigned char bit_addr;
> > +	unsigned int byte_addr;
> > +	unsigned short ecc_odd, ecc_even, read_ecc_lower, read_ecc_upper;
> > +	unsigned short calc_ecc_lower, calc_ecc_upper;
> > +
> > +	read_ecc_lower = (read_ecc[0] | (read_ecc[1] << 8)) &
> > +			  PL353_ECC_BIT_MASK;
> > +	read_ecc_upper = ((read_ecc[1] >> 4) | (read_ecc[2] << 4)) &
> > +			  PL353_ECC_BIT_MASK;
> > +
> > +	calc_ecc_lower = (calc_ecc[0] | (calc_ecc[1] << 8)) &
> > +			  PL353_ECC_BIT_MASK;
> > +	calc_ecc_upper = ((calc_ecc[1] >> 4) | (calc_ecc[2] << 4)) &
> > +			  PL353_ECC_BIT_MASK;
> > +
> > +	ecc_odd = read_ecc_lower ^ calc_ecc_lower;
> > +	ecc_even = read_ecc_upper ^ calc_ecc_upper;
> > +
> > +	/* no error */
> > +	if (!ecc_odd && !ecc_even)
> > +		return 0;
> > +
> > +	if (ecc_odd == (~ecc_even & PL353_ECC_BIT_MASK)) {
> > +		/* bits [11:3] of error code is byte offset */
> > +		byte_addr = (ecc_odd >> 3) & PL353_ECC_BITS_BYTEOFF_MASK;
> > +		/* bits [2:0] of error code is bit offset */
> > +		bit_addr = ecc_odd & PL353_ECC_BITS_BITOFF_MASK;
> > +		/* Toggling error bit */
> > +		buf[byte_addr] ^= (BIT(bit_addr));
> > +		return 1;
> > +	}
> > +
> > +	/* one error in parity */
> > +	if (hweight32(ecc_odd | ecc_even) == 1)
> > +		return 1;
> > +
> > +	/* Uncorrectable error */
> > +	return -1;
> > +}
> > +
> > +static void pl353_prepare_cmd(struct mtd_info *mtd, struct nand_chip *chip,
> > +			      int page, int column, int start_cmd, int end_cmd,
> > +			      bool read)
> > +{
> > +	unsigned long data_phase_addr;
> > +	u32 end_cmd_valid = 0;
> > +	unsigned long cmd_phase_addr = 0, cmd_data = 0;
> > +
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +
> > +	end_cmd_valid = read ? 1 : 0;
> > +
> > +	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
> 
> do you really need this cast?
As I said above, during command and data phases, we have to update the AXI Read/Write addresses with cycles, start command, end command
And some extra info. Hence I am converting it to a value and then adding the above values and then again converting back as an
Address.

> 
> > +			 ((xnfc->addr_cycles
> > +			 << ADDR_CYCLES_SHIFT) |
> > +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > +			 (COMMAND_PHASE) |
> > +			 (end_cmd << END_CMD_SHIFT) |
> > +			 (start_cmd << START_CMD_SHIFT));
> 
> So the number of address cycles changes the address where you should write the address
> cycles? that's weird, no?
I agree, but the implementation of PL353 is like that.
As I pointed the spec above, for every transfer we have to frame AXI Write address and Read address.

> 
> > +
> > +	/* Get the data phase address */
> > +	data_phase_addr = (unsigned long __force)xnfc->nand_base +
> > +			  ((0x0 << CLEAR_CS_SHIFT) |
> > +			  (0 << END_CMD_VALID_SHIFT) |
> > +			  (DATA_PHASE) |
> > +			  (end_cmd << END_CMD_SHIFT) |
> > +			  (0x0 << ECC_LAST_SHIFT));
> > +
> Same question here?
> 
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> 
> This should be done only once in the probe
No, as explained above, once we frame the Axi Write address/Read address with valid data, then we
Are converting back as memory address with the casting.
Do you see any issues with that?
Let me know, is there an alternative to achieve the same. 
All is about, constructing AXI Write address and Read address during command and data phases.
> 
> > +
> > +	if (chip->options & NAND_BUSWIDTH_16)
> > +		column /= 2;
> > +	cmd_data = column;
> 
> Please rename cmd_data because assigning a column (ie, an address
> cycle) to a variable name "cmd_data" is weird.
Ok, I will change it.
> 
> > +	if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> > +		cmd_data |= page << 16;
> > +		/* Another address cycle for devices > 128MiB */
> > +		if (chip->options & NAND_ROW_ADDR_3) {
> > +			writel_relaxed(cmd_data,
> > +				       (void __iomem * __force)cmd_phase_addr);
> > +			cmd_data = (page >> 16);
> > +		}
> > +	} else {
> > +		cmd_data |= page << 8;
> > +	}
> > +
> > +	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr); }
> > +
> > +/**
> > + * pl353_nand_read_oob - [REPLACEABLE] the most common OOB data read function
> > + * @mtd:	Pointer to the mtd info structure
> 
> NAND and MTD are always upper case in plain english. Here I suppose you refer to the
> structure name, the use the exact name "mtd_info".
Ok, I will correct it.
> 
> 
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @page:	Page number to read
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
> > +			       int page)
> > +{
> > +	unsigned long data_phase_addr;
> > +	u8 *p;
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > +	chip->pagebuf = -1;
> > +	if (mtd->writesize < PL353_NAND_ECC_SIZE)
> > +		return 0;
> > +
> > +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_READ0,
> > +			  NAND_CMD_READSTART, 1);
> > +
> > +	nand_wait_ready(mtd);
> > +
> > +	p = chip->oob_poi;
> > +	pl353_nand_read_data_op(chip, p,
> > +				(mtd->oobsize -
> > +				PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr += nand_offset;
> 
> This is still a foreign language for me, why do you do the math everytime? And please explain
> what's done here, it's absolutely not clear for me.
Explained above.
> 
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> 
> You should not need the cast.
> 
> > +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_oob - [REPLACEABLE] the most common OOB data write
> function
> > + * @mtd:	Pointer to the mtd info structure
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @page:	Page number to write
> > + *
> > + * Return:	Zero on success and EIO on failure
> > + */
> > +static int pl353_nand_write_oob(struct mtd_info *mtd, struct nand_chip *chip,
> > +				int page)
> > +{
> > +	const u8 *buf = chip->oob_poi;
> > +	unsigned long data_phase_addr;
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +	u32 addrcycles = 0;
> > +
> > +	chip->pagebuf = -1;
> > +	addrcycles = xnfc->addr_cycles;
> > +	pl353_prepare_cmd(mtd, chip, page, mtd->writesize, NAND_CMD_SEQIN,
> > +			  NAND_CMD_PAGEPROG, 0);
> > +
> > +	pl353_nand_write_data_op(mtd, buf,
> > +				 (mtd->oobsize -
> > +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	buf += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_write_data_op(mtd, buf,
> PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	nand_wait_ready(mtd);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_read_page_raw - [Intern] read raw page data without ecc
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the data buffer
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to read
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_read_page_raw(struct mtd_info *mtd,
> > +				    struct nand_chip *chip,
> > +				    u8 *buf, int oob_required, int page) {
> > +	unsigned long data_phase_addr;
> > +	u8 *p;
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > +	pl353_nand_read_data_op(chip, buf, mtd->writesize);
> > +	p = chip->oob_poi;
> > +	pl353_nand_read_data_op(chip, p,
> > +				(mtd->oobsize -
> > +				PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_write_page_raw - [Intern] raw page write function
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the data buffer
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to write
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_write_page_raw(struct mtd_info *mtd,
> > +				     struct nand_chip *chip,
> > +				     const u8 *buf, int oob_required,
> > +				     int page)
> > +{
> > +	unsigned long data_phase_addr;
> > +	u8 *p;
> > +
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > +	pl353_nand_write_data_op(mtd, buf, mtd->writesize);
> > +	p = chip->oob_poi;
> > +	pl353_nand_write_data_op(mtd, p,
> > +				 (mtd->oobsize -
> > +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * nand_write_page_hwecc - Hardware ECC based page write function
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the data buffer
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to write
> > + *
> > + * This functions writes data and hardware generated ECC values in to the page.
> > + *
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_write_page_hwecc(struct mtd_info *mtd,
> > +				       struct nand_chip *chip,
> > +				       const u8 *buf, int oob_required,
> > +				       int page)
> > +{
> > +	int eccsize = chip->ecc.size;
> > +	int eccsteps = chip->ecc.steps;
> > +	u8 *ecc_calc = chip->ecc.calc_buf;
> > +	u8 *oob_ptr;
> > +	const u8 *p = buf;
> > +	u32 ret;
> > +	unsigned long data_phase_addr;
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_SEQIN,
> > +			  NAND_CMD_PAGEPROG, 0);
> > +
> > +	for ( ; (eccsteps - 1); eccsteps--) {
> > +		pl353_nand_write_data_op(mtd, p, eccsize);
> > +		p += eccsize;
> > +	}
> > +	pl353_nand_write_data_op(mtd, p,
> > +				 (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	/* Set ECC Last bit to 1 */
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_write_data_op(mtd, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	p = buf;
> > +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> 
> You should check the returned value?
Ok, I will update it.
> 
> > +
> > +	/* Wait for ECC to be calculated and read the error values */
> > +	ret = mtd_ooblayout_set_eccbytes(mtd, ecc_calc, chip->oob_poi,
> > +					 0, chip->ecc.total);
> > +	if (ret)
> > +		return ret;
> > +	/* Clear ECC last bit */
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > +	/* Write the spare area with ECC bytes */
> > +	oob_ptr = chip->oob_poi;
> > +	pl353_nand_write_data_op(mtd, oob_ptr,
> > +				 (mtd->oobsize -
> > +				 PL353_NAND_LAST_TRANSFER_LENGTH));
> > +
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr |= (1 << END_CMD_VALID_SHIFT);
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	pl353_nand_write_data_op(mtd, oob_ptr,
> PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	nand_wait_ready(mtd);
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_read_page_hwecc - Hardware ECC based page read function
> > + * @mtd:		Pointer to the mtd info structure
> > + * @chip:		Pointer to the NAND chip info structure
> > + * @buf:		Pointer to the buffer to store read data
> > + * @oob_required:	Caller requires OOB data read to chip->oob_poi
> > + * @page:		Page number to read
> > + *
> > + * This functions reads data and checks the data integrity by
> > +comparing
> > + * hardware generated ECC values and read ECC values from spare area.
> > + * There is a limitation in SMC controller, that we must set ECC LAST
> > +on
> > + * last data phase access, to tell ECC block not to expect any data further.
> > + * Ex:  When number of ECC STEPS are 4, then till 3 we will write to
> > +flash
> > + * using SMC with HW ECC enabled. And for the last ECC STEP, we will
> > +subtract
> > + * 4bytes from page size, and will initiate a transfer. And the
> > +remaining 4 as
> > + * one more transfer with ECC_LAST bit set in NAND data phase
> > +register to
> > + * notify ECC block not to expect any more data. The last block
> > +should be align
> > + * with end of 512 byte block. Because of this limitation, we are not
> > +using
> > + * core routines.
> > + *
> > + * Return:	0 always and updates ECC operation status in to MTD structure
> > + */
> > +static int pl353_nand_read_page_hwecc(struct mtd_info *mtd,
> > +				      struct nand_chip *chip,
> > +				      u8 *buf, int oob_required, int page) {
> > +	int i, stat, eccsize = chip->ecc.size;
> > +	int eccbytes = chip->ecc.bytes;
> > +	int eccsteps = chip->ecc.steps;
> > +	u8 *p = buf;
> > +	u8 *ecc_calc = chip->ecc.calc_buf;
> > +	u8 *ecc = chip->ecc.code_buf;
> > +	unsigned int max_bitflips = 0;
> > +	u8 *oob_ptr;
> > +	u32 ret;
> > +	unsigned long data_phase_addr;
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long nand_offset = (unsigned long __force)xnfc->nand_base;
> > +
> > +	pl353_prepare_cmd(mtd, chip, page, 0, NAND_CMD_READ0,
> > +			  NAND_CMD_READSTART, 1);
> > +	nand_wait_ready(mtd);
> > +
> > +	for ( ; (eccsteps - 1); eccsteps--) {
> > +		pl353_nand_read_data_op(chip, p, eccsize);
> > +		p += eccsize;
> > +	}
> > +	pl353_nand_read_data_op(chip, p,
> > +				(eccsize - PL353_NAND_LAST_TRANSFER_LENGTH));
> > +	p += (eccsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	/* Set ECC Last bit to 1 */
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +	pl353_nand_read_data_op(chip, p, PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	/* Read the calculated ECC value */
> > +	p = buf;
> > +	chip->ecc.calculate(mtd, p, &ecc_calc[0]);
> > +
> 
> You should check the returned value?
Ok, I will update it.

> 
> > +	/* Clear ECC last bit */
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr &= ~PL353_NAND_ECC_LAST;
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > +	/* Read the stored ECC value */
> > +	oob_ptr = chip->oob_poi;
> > +	pl353_nand_read_data_op(chip, oob_ptr,
> > +				(mtd->oobsize -
> > +				PL353_NAND_LAST_TRANSFER_LENGTH));
> > +
> > +	/* de-assert chip select */
> > +	data_phase_addr = (unsigned long __force)xnfc->nandaddr;
> > +	data_phase_addr -= nand_offset;
> > +	data_phase_addr |= PL353_NAND_CLEAR_CS;
> > +	data_phase_addr += nand_offset;
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > +	oob_ptr += (mtd->oobsize - PL353_NAND_LAST_TRANSFER_LENGTH);
> > +	pl353_nand_read_data_op(chip, oob_ptr,
> > +PL353_NAND_LAST_TRANSFER_LENGTH);
> > +
> > +	ret = mtd_ooblayout_get_eccbytes(mtd, ecc, chip->oob_poi, 0,
> > +					 chip->ecc.total);
> > +	if (ret)
> > +		return ret;
> > +
> > +	eccsteps = chip->ecc.steps;
> > +	p = buf;
> > +
> > +	/* Check ECC error for all blocks and correct if it is correctable */
> > +	for (i = 0 ; eccsteps; eccsteps--, i += eccbytes, p += eccsize) {
> > +		stat = chip->ecc.correct(mtd, p, &ecc[i], &ecc_calc[i]);
> > +		if (stat < 0) {
> > +			mtd->ecc_stats.failed++;
> > +		} else {
> > +			mtd->ecc_stats.corrected += stat;
> > +			max_bitflips = max_t(unsigned int, max_bitflips, stat);
> > +		}
> > +	}
> > +
> > +	return max_bitflips;
> > +}
> > +
> > +/**
> > + * pl353_nand_select_chip - Select the flash device
> > + * @mtd:	Pointer to the mtd info structure
> > + * @chip:	Pointer to the NAND chip info structure
> > + *
> > + * This function is empty as the NAND controller handles chip select
> > +line
> > + * internally based on the chip address passed in command and data phase.
> > + */
> > +static void pl353_nand_select_chip(struct mtd_info *mtd, int chip) {
> > +}
> > +
> > +/* NAND framework ->exec_op() hooks and related helpers */ static
> > +void pl353_nfc_parse_instructions(struct nand_chip *chip,
> > +					 const struct nand_subop *subop,
> > +					 struct pl353_nfc_op *nfc_op)
> > +{
> > +	const struct nand_op_instr *instr = NULL;
> > +	unsigned int op_id, offset, naddrs;
> > +	int i, len;
> > +	const u8 *addrs;
> > +
> > +	memset(nfc_op, 0, sizeof(struct pl353_nfc_op));
> > +	for (op_id = 0; op_id < subop->ninstrs; op_id++) {
> > +		nfc_op->len = nand_subop_get_data_len(subop, op_id);
> > +		len = nand_subop_get_data_len(subop, op_id);
> > +		instr = &subop->instrs[op_id];
> > +
> > +		switch (instr->type) {
> > +		case NAND_OP_CMD_INSTR:
> > +			nfc_op->type = NAND_OP_CMD_INSTR;
> > +			if (op_id)
> > +				nfc_op->cmnds[1] = instr->ctx.cmd.opcode;
> > +			else
> > +				nfc_op->cmnds[0] = instr->ctx.cmd.opcode;
> > +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> > +			break;
> > +
> > +		case NAND_OP_ADDR_INSTR:
> > +			offset = nand_subop_get_addr_start_off(subop, op_id);
> > +			naddrs = nand_subop_get_num_addr_cyc(subop, op_id);
> > +			addrs = &instr->ctx.addr.addrs[offset];
> > +			nfc_op->addrs = instr->ctx.addr.addrs[offset];
> > +			for (i = 0; i < min_t(unsigned int, 4, naddrs); i++) {
> > +				nfc_op->addrs |= instr->ctx.addr.addrs[i] <<
> > +						 (8 * i);
> > +			}
> > +
> > +			if (naddrs >= 5)
> > +				nfc_op->addr5 = addrs[4];
> > +			if (naddrs >= 6)
> > +				nfc_op->addr6 = addrs[5];
> > +			nfc_op->naddrs = nand_subop_get_num_addr_cyc(subop,
> > +								     op_id);
> > +			nfc_op->cle_ale_delay_ns = instr->delay_ns;
> > +			break;
> > +
> > +		case NAND_OP_DATA_IN_INSTR:
> > +			nfc_op->data_instr = instr;
> > +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> > +			nfc_op->data_instr_idx = op_id;
> > +			break;
> > +
> > +		case NAND_OP_DATA_OUT_INSTR:
> > +			nfc_op->data_instr = instr;
> > +			nfc_op->type = NAND_OP_DATA_IN_INSTR;
> > +			nfc_op->data_instr_idx = op_id;
> > +			break;
> > +
> > +		case NAND_OP_WAITRDY_INSTR:
> > +			nfc_op->rdy_timeout_ms = instr->ctx.waitrdy.timeout_ms;
> > +			nfc_op->rdy_delay_ns = instr->delay_ns;
> > +			break;
> > +		}
> > +	}
> > +}
> > +
> > +static void cond_delay(unsigned int ns) {
> > +	if (!ns)
> > +		return;
> > +
> > +	if (ns < 10000)
> > +		ndelay(ns);
> > +	else
> > +		udelay(DIV_ROUND_UP(ns, 1000));
> > +}
> > +
> > +/**
> > + * pl353_nand_cmd_function - Send command to NAND device
> > + * @chip:	Pointer to the NAND chip info structure
> > + * @subop:	Pointer to array of instructions
> > + * Return:	Always return zero
> > + */
> > +static int pl353_nand_cmd_function(struct nand_chip *chip,
> > +				   const struct nand_subop *subop)
> 
> Please don't use this name, too close from the cmdfunc() hook we are trying to remove.
Sure, I will change it.

> 
> > +{
> > +	struct mtd_info *mtd = nand_to_mtd(chip);
> > +	const struct nand_op_instr *instr;
> > +	struct pl353_nfc_op nfc_op = {};
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	unsigned long cmd_data = 0, end_cmd_valid = 0;
> > +	unsigned long cmd_phase_addr, data_phase_addr, end_cmd;
> > +	unsigned int op_id, len, offset;
> > +	bool reading;
> > +
> > +	pl353_nfc_parse_instructions(chip, subop, &nfc_op);
> > +	instr = nfc_op.data_instr;
> > +	op_id = nfc_op.data_instr_idx;
> > +	len = nand_subop_get_data_len(subop, op_id);
> > +	offset = nand_subop_get_data_start_off(subop, op_id);
> > +
> > +	pl353_smc_clr_nand_int();
> > +	/* Get the command phase address */
> > +	if (nfc_op.cmnds[1] != 0) {
> > +		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN)
> > +			end_cmd_valid = 0;
> > +		else
> > +			end_cmd_valid = 1;
> > +		end_cmd = nfc_op.cmnds[1];
> > +	}  else {
> > +		end_cmd = 0x0;
> > +	}
> > +
> > +	/*
> > +	 * The SMC defines two phases of commands when transferring data to or
> > +	 * from NAND flash.
> > +	 * Command phase: Commands and optional address information are written
> > +	 * to the NAND flash.The command and address can be associated with
> > +	 * either a data phase operation to write to or read from the array,
> > +	 * or a status/ID register transfer.
> > +	 * Data phase: Data is either written to or read from the NAND flash.
> > +	 * This data can be either data transferred to or from the array,
> > +	 * or status/ID register information.
> > +	 */
> > +	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +
> > +			 ((nfc_op.naddrs << ADDR_CYCLES_SHIFT) |
> > +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > +			 (COMMAND_PHASE) |
> > +			 (end_cmd << END_CMD_SHIFT) |
> > +			 (nfc_op.cmnds[0] << START_CMD_SHIFT));
> > +
> > +	/* Get the data phase address */
> > +	end_cmd_valid = 0;
> > +
> > +	data_phase_addr = (unsigned long __force)xnfc->nand_base +
> > +			  ((0x0 << CLEAR_CS_SHIFT) |
> > +			  (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > +			  (DATA_PHASE) |
> > +			  (end_cmd << END_CMD_SHIFT) |
> > +			  (0x0 << ECC_LAST_SHIFT));
> > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;
> > +
> > +	/* Command phase AXI Read & Write */
> > +	if (nfc_op.naddrs >= 5) {
> > +		if (mtd->writesize > PL353_NAND_ECC_SIZE) {
> > +			cmd_data = nfc_op.addrs;
> > +			/* Another address cycle for devices > 128MiB */
> > +			if (chip->options & NAND_ROW_ADDR_3) {
> > +				writel_relaxed(cmd_data,
> > +					       (void __iomem * __force)
> > +					       cmd_phase_addr);
> > +				cmd_data = nfc_op.addr5;
> > +				if (nfc_op.naddrs >= 6)
> > +					cmd_data |= (nfc_op.addr6 << 8);
> > +			}
> > +		}
> > +	}  else {
> > +		if (nfc_op.addrs != -1) {
> > +			int column = nfc_op.addrs;
> > +			/*
> > +			 * Change read/write column, read id etc
> > +			 * Adjust columns for 16 bit bus width
> > +			 */
> > +			if ((chip->options & NAND_BUSWIDTH_16) &&
> > +			    (nfc_op.cmnds[0] == NAND_CMD_READ0 ||
> > +				nfc_op.cmnds[0] == NAND_CMD_SEQIN ||
> > +				nfc_op.cmnds[0] == NAND_CMD_RNDOUT ||
> > +				nfc_op.cmnds[0] == NAND_CMD_RNDIN)) {
> > +				column >>= 1;
> > +			}
> > +			cmd_data = column;
> > +		}
> > +	}
> > +	writel_relaxed(cmd_data, (void __iomem * __force)cmd_phase_addr);
> > +
> > +	if (!nfc_op.data_instr) {
> > +		if (nfc_op.rdy_timeout_ms)
> > +			nand_wait_ready(mtd);
> > +		return 0;
> > +	}
> > +
> > +	reading = (nfc_op.data_instr->type == NAND_OP_DATA_IN_INSTR);
> > +	if (!reading) {
> > +		if (nfc_op.cmnds[0] == NAND_CMD_SEQIN &&
> > +		    nfc_op.cmnds[1] == NAND_CMD_PAGEPROG) {
> > +			pl353_nand_write_page_raw(mtd, chip,
> > +						  instr->ctx.data.buf.out, 0,
> > +						  nfc_op.addrs);
> > +
> > +		} else {
> > +			pl353_nand_write_data_op(mtd, instr->ctx.data.buf.out,
> > +						 len);
> > +		}
> > +		if (nfc_op.rdy_timeout_ms)
> > +			nand_wait_ready(mtd);
> > +		cond_delay(nfc_op.rdy_delay_ns);
> > +	}
> > +	if (reading) {
> > +		cond_delay(nfc_op.rdy_delay_ns);
> > +		if (nfc_op.rdy_timeout_ms)
> > +			nand_wait_ready(mtd);
> > +		pl353_nand_read_data_op(chip, instr->ctx.data.buf.in, len);
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +static const struct nand_op_parser pl353_nfc_op_parser = NAND_OP_PARSER
> > +	(NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> > +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true),
> > +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 7),
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false),
> > +		NAND_OP_PARSER_PAT_DATA_IN_ELEM(false, 2048)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(true, 7),
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(false)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false),
> > +		NAND_OP_PARSER_PAT_ADDR_ELEM(false, 8),
> > +		NAND_OP_PARSER_PAT_DATA_OUT_ELEM(false, 2048),
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(true),
> > +		NAND_OP_PARSER_PAT_WAITRDY_ELEM(true)),
> > +	NAND_OP_PARSER_PATTERN
> > +		(pl353_nand_cmd_function,
> > +		NAND_OP_PARSER_PAT_CMD_ELEM(false)),
> > +	);
> > +
> > +static int pl353_nfc_exec_op(struct nand_chip *chip,
> > +			     const struct nand_operation *op,
> > +			     bool check_only)
> > +{
> > +	return nand_op_parser_exec_op(chip, &pl353_nfc_op_parser,
> > +					      op, check_only);
> > +}
> > +
> > +/**
> > + * pl353_nand_device_ready - Check device ready/busy line
> > + * @mtd:	Pointer to the mtd_info structure
> > + *
> > + * Return:	0 on busy or 1 on ready state
> > + */
> > +static int pl353_nand_device_ready(struct mtd_info *mtd {
> > +	if (pl353_smc_get_nand_int_status_raw()) {
> > +		pl353_smc_clr_nand_int();
> > +		return 1;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_ecc_init - Initialize the ecc information as per the ecc mode
> > + * @mtd:	Pointer to the mtd_info structure
> > + * @ecc:	Pointer to ECC control structure
> > + * @ecc_mode:	ondie ecc status
> > + *
> > + * This function initializes the ecc block and functional pointers as
> > +per the
> > + * ecc mode
> > + *
> > + * Return:	0 on success or negative errno.
> > + */
> > +static int pl353_nand_ecc_init(struct mtd_info *mtd, struct nand_ecc_ctrl *ecc,
> > +				int ecc_mode)
> > +{
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	int err = 0;
> > +
> > +	if (ecc_mode == NAND_ECC_ON_DIE) {
> > +		pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_BYPASS);
> > +		/*
> > +		 * On-Die ECC spare bytes offset 8 is used for ECC codes
> > +		 * Use the BBT pattern descriptors
> > +		 */
> > +		chip->bbt_td = &bbt_main_descr;
> > +		chip->bbt_md = &bbt_mirror_descr;
> > +		bitmap_set(chip->parameters.get_feature_list,
> > +			   ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> > +		bitmap_set(chip->parameters.set_feature_list,
> > +			   ONFI_FEATURE_ON_DIE_ECC,
> ONFI_FEATURE_ON_DIE_ECC_EN);
> > +	} else {
> > +		ecc->read_oob = pl353_nand_read_oob;
> > +		ecc->write_oob = pl353_nand_write_oob;
> > +
> > +		ecc->mode = NAND_ECC_HW;
> > +		/* Hardware ECC generates 3 bytes ECC code for each 512 bytes */
> > +		ecc->bytes = 3;
> > +		ecc->strength = 1;
> > +		ecc->calculate = pl353_nand_calculate_hwecc;
> > +		ecc->correct = pl353_nand_correct_data;
> > +		ecc->read_page = pl353_nand_read_page_hwecc;
> > +		ecc->size = PL353_NAND_ECC_SIZE;
> > +		ecc->write_page = pl353_nand_write_page_hwecc;
> > +		pl353_smc_set_ecc_pg_size(mtd->writesize);
> > +		switch (mtd->writesize) {
> > +		case SZ_512:
> > +		case SZ_1K:
> > +		case SZ_2K:
> > +			pl353_smc_set_ecc_mode(PL353_SMC_ECCMODE_APB);
> > +			break;
> > +		default:
> > +			ecc->calculate = nand_calculate_ecc;
> > +			ecc->correct = nand_correct_data;
> > +			ecc->size = 256;
> > +			break;
> > +		}
> > +		if (mtd->writesize <= SZ_512)
> > +			xnfc->addr_cycles = 1;
> > +		else
> > +			xnfc->addr_cycles = 2;
> > +
> > +		if (chip->options & NAND_ROW_ADDR_3)
> > +			xnfc->addr_cycles += 3;
> > +		else
> > +			xnfc->addr_cycles += 2;
> > +
> > +		if (mtd->oobsize == 16) {
> > +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout16_ops);
> > +		} else if (mtd->oobsize == 64) {
> > +			mtd_set_ooblayout(mtd, &pl353_ecc_ooblayout64_ops);
> > +		} else {
> > +			err = -ENXIO;
> > +			dev_err(xnfc->dev, "Unsupported oob Layout\n");
> > +		}
> > +	}
> > +	return err;
> > +}
> > +
> > +static int pl353_setup_data_interface(struct mtd_info *mtd, int csline,
> > +				       const struct nand_data_interface *conf) {
> > +	struct nand_chip *chip = mtd_to_nand(mtd);
> > +	struct pl353_nand_info *xnfc =
> > +		container_of(chip, struct pl353_nand_info, chip);
> > +	const struct nand_sdr_timings *sdr;
> > +	u32 timings[7], mckperiodps;
> > +
> > +	sdr = nand_get_sdr_timings(conf);
> > +	if (IS_ERR(sdr))
> > +		return PTR_ERR(sdr);
> > +
> > +	/*
> > +	 * SDR timings are given in pico-seconds while NFC timings must be
> > +	 * expressed in NAND controller clock cycles.
> > +	 */
> > +	mckperiodps = NSEC_PER_SEC / clk_get_rate(xnfc->mclk);
> > +	mckperiodps *= 1000;
> > +	if (sdr->tRC_min <= 20000)
> > +		/*
> > +		 * PL353 SMC needs one extra read cycle in SDR Mode 5
> > +		 * This is not written anywhere in the datasheet but
> > +		 * the results observed during testing.
> 
> Oh, that's bad.
> 
> > +		 */
> > +		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps) + 1;
> > +	else
> > +		timings[0] = DIV_ROUND_UP(sdr->tRC_min, mckperiodps);
> > +
> > +	timings[1] = DIV_ROUND_UP(sdr->tWC_min, mckperiodps);
> > +	/*
> > +	 * For all SDR modes, PL353 SMC needs tREA max value as 1
> > +	 * These results observed during testing.
> 
> s/These results/Results/
Ok, will update.
> 
> > +	 */
> > +	timings[2] = PL353_TREA_MAX_VALUE;
> > +	timings[3] = DIV_ROUND_UP(sdr->tWP_min, mckperiodps);
> > +	timings[4] = DIV_ROUND_UP(sdr->tCLR_min, mckperiodps);
> > +	timings[5] = DIV_ROUND_UP(sdr->tAR_min, mckperiodps);
> > +	timings[6] = DIV_ROUND_UP(sdr->tRR_min, mckperiodps);
> > +
> > +	if (csline == NAND_DATA_IFACE_CHECK_ONLY)
> > +		return 0;
> 
> You should move this to the top.
Ok, I will change it.
> 
> > +
> > +	pl353_smc_set_cycles(timings);
> > +
> > +	return 0;
> > +}
> > +/**
> > + * pl353_nand_probe - Probe method for the NAND driver
> > + * @pdev:	Pointer to the platform_device structure
> > + *
> > + * This function initializes the driver data structures and the hardware.
> > + * The NAND driver has dependency with the pl353_smc memory
> > +controller
> > + * driver for initializing the NAND timing parameters, bus width, ECC
> > +modes,
> > + * control and status information.
> > + *
> > + * Return:	0 on success or error value on failure
> > + */
> > +static int pl353_nand_probe(struct platform_device *pdev) {
> > +	struct pl353_nand_info *xnfc;
> > +	struct mtd_info *mtd;
> > +	struct nand_chip *chip;
> > +	struct resource *res;
> > +	struct device_node *np;
> > +	u32 ret;
> > +
> > +	xnfc = devm_kzalloc(&pdev->dev, sizeof(*xnfc), GFP_KERNEL);
> > +	if (!xnfc)
> > +		return -ENOMEM;
> > +	xnfc->dev = &pdev->dev;
> > +	/* Map physical address of NAND flash */
> > +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > +	xnfc->nand_base = devm_ioremap_resource(xnfc->dev, res);
> > +	if (IS_ERR(xnfc->nand_base))
> > +		return PTR_ERR(xnfc->nand_base);
> > +
> > +	chip = &xnfc->chip;
> > +	mtd = nand_to_mtd(chip);
> > +	chip->exec_op = pl353_nfc_exec_op;
> > +	nand_set_controller_data(chip, xnfc);
> > +	mtd->priv = chip;
> > +	mtd->owner = THIS_MODULE;
> > +	if (!mtd->name) {
> > +		/*
> > +		 * If the new bindings are used and the bootloader has not been
> > +		 * updated to pass a new mtdparts parameter on the cmdline, you
> > +		 * should define the following property in your NAND node, ie:
> > +		 *
> > +		 *	label = "pl353-nand";
> > +		 *
> > +		 * This way, mtd->name will be set by the core when
> > +		 * nand_set_flash_node() is called.
> > +		 */
> > +		mtd->name = devm_kasprintf(xnfc->dev, GFP_KERNEL,
> > +					   "%s", PL353_NAND_DRIVER_NAME);
> > +		if (!mtd->name) {
> > +			dev_err(xnfc->dev, "Failed to allocate mtd->name\n");
> > +			return -ENOMEM;
> > +		}
> > +	}
> > +	nand_set_flash_node(chip, xnfc->dev->of_node);
> > +
> > +	/* Set the driver entry points for MTD */
> > +	chip->dev_ready = pl353_nand_device_ready;
> > +	chip->select_chip = pl353_nand_select_chip;
> > +	/* If we don't set this delay driver sets 20us by default */
> > +	np = of_get_next_parent(xnfc->dev->of_node);
> > +	xnfc->mclk = of_clk_get(np, 0);
> > +	if (IS_ERR(xnfc->mclk)) {
> > +		dev_err(xnfc->dev, "Failed to retrieve MCK clk\n");
> > +		return PTR_ERR(xnfc->mclk);
> > +	}
> > +	chip->chip_delay = 30;
> > +	/* Set the device option and flash width */
> > +	chip->options = NAND_BUSWIDTH_AUTO;
> > +	chip->bbt_options = NAND_BBT_USE_FLASH;
> > +	platform_set_drvdata(pdev, xnfc);
> > +	chip->setup_data_interface = pl353_setup_data_interface;
> > +	/* first scan to find the device and get the page size */
> > +	if (nand_scan_ident(mtd, 1, NULL)) {
> > +		dev_err(xnfc->dev, "nand_scan_ident for NAND failed\n");
> > +		return -ENXIO;
> > +	}
> > +	ret = pl353_nand_ecc_init(mtd, &chip->ecc, chip->ecc.mode);
> > +	if (chip->options & NAND_BUSWIDTH_16)
> > +		pl353_smc_set_buswidth(PL353_SMC_MEM_WIDTH_16);
> > +	/* second phase scan */
> > +	if (nand_scan_tail(mtd)) {
> > +		dev_err(xnfc->dev, "nand_scan_tail for NAND failed\n");
> > +		return -ENXIO;
> > +	}
> > +
> 
> I suggest you to wait for v4.19-rc1 to be out and then rebase on top of it as this cycle we
> changed a lot of things.
> 
> Particularly, nand_scan_ident() and nand_scan_tail() are not exposed anymore, you should
> create nand_controller_ops with an
> ->attach_chip() hook that does everything between ident() and tail()
> and use nand_scan() instead.
Sure Miquel, I will modify the driver as per v4.19-rc1, once it is out.
And thanks for you review again and thanks for your comments.
Compare to the initial version of this patch series, I think the current driver is in good shape now.
Thanks again for the review.

> 
> > +	ret = mtd_device_register(mtd, NULL, 0);
> > +	if (ret) {
> > +		dev_err(xnfc->dev, "Failed to register mtd device: %d\n", ret);
> > +		nand_cleanup(chip);
> > +		return ret;
> > +	}
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * pl353_nand_remove - Remove method for the NAND driver
> > + * @pdev:	Pointer to the platform_device structure
> > + *
> > + * This function is called if the driver module is being unloaded. It
> > +frees all
> > + * resources allocated to the device.
> > + *
> > + * Return:	0 on success or error value on failure
> > + */
> > +static int pl353_nand_remove(struct platform_device *pdev) {
> > +	struct pl353_nand_info *xnfc = platform_get_drvdata(pdev);
> > +	struct mtd_info *mtd = nand_to_mtd(&xnfc->chip);
> > +
> > +	/* Release resources, unregister device */
> > +	nand_release(mtd);
> > +
> > +	return 0;
> > +}
> > +
> > +/* Match table for device tree binding */ static const struct
> > +of_device_id pl353_nand_of_match[] = {
> > +	{ .compatible = "arm,pl353-nand-r2p1" },
> > +	{},
> > +};
> > +MODULE_DEVICE_TABLE(of, pl353_nand_of_match);
> > +
> > +/*
> > + * pl353_nand_driver - This structure defines the NAND subsystem
> > +platform driver  */ static struct platform_driver pl353_nand_driver =
> > +{
> > +	.probe		= pl353_nand_probe,
> > +	.remove		= pl353_nand_remove,
> > +	.driver		= {
> > +		.name	= PL353_NAND_DRIVER_NAME,
> > +		.of_match_table = pl353_nand_of_match,
> > +	},
> > +};
> > +
> > +module_platform_driver(pl353_nand_driver);
> > +
> > +MODULE_AUTHOR("Xilinx, Inc.");
> > +MODULE_ALIAS("platform:" PL353_NAND_DRIVER_NAME);
> > +MODULE_DESCRIPTION("ARM PL353 NAND Flash Driver");
> > +MODULE_LICENSE("GPL");
> 
> 
> Thanks,
> Miquèl

Regards,
Naga Sureshkumar Relli

Re: [LINUX PATCH v11 3/3] mtd: rawnand: pl353: Add basic driver for arm pl353 smc nand interface

[Miquel Raynal]

Hi Naga,

> > > +/**
> > > + * pl353_nand_read_data_op - read chip data into buffer
> > > + * @chip:	Pointer to the NAND chip info structure
> > > + * @in:		Pointer to the buffer to store read data
> > > + * @len:	Number of bytes to read
> > > + * Return:	Always return zero
> > > + */
> > > +static int pl353_nand_read_data_op(struct nand_chip *chip,
> > > +				   u8 *in,
> > > +				   unsigned int len)
> > > +{
> > > +	int i;
> > > +	struct pl353_nand_info *xnfc =
> > > +		container_of(chip, struct pl353_nand_info, chip);
> > > +
> > > +	if (IS_ALIGNED((uint32_t)in, sizeof(uint32_t)) &&
> > > +	    IS_ALIGNED(len, sizeof(uint32_t))) {
> > > +		u32 *ptr = (u32 *)in;
> > > +
> > > +		len /= 4;
> > > +		for (i = 0; i < len; i++)
> > > +			ptr[i] = readl(xnfc->nandaddr);
> > > +	} else {
> > > +		for (i = 0; i < len; i++)
> > > +			in[i] = readb(xnfc->nandaddr);
> > > +	}  
> > 
> > What about reading 0-3 bytes with readb if the driver is not aligned, then doing aligned
> > access with readl until readb must be used again for the last 0-3 bytes?  
> The else case is handling that right?

No it's not. The else case reads byte per byte, always.

[...]

> > > +static int pl353_nand_calculate_hwecc(struct mtd_info *mtd,
> > > +				      const u8 *data, u8 *ecc)
> > > +{
> > > +	u32 ecc_value;
> > > +	u8 ecc_reg, ecc_byte, ecc_status;
> > > +	unsigned long timeout = jiffies + PL353_NAND_ECC_BUSY_TIMEOUT;
> > > +
> > > +	/* Wait till the ECC operation is complete or timeout */
> > > +	do {
> > > +		if (pl353_smc_ecc_is_busy())
> > > +			cpu_relax();
> > > +		else
> > > +			break;
> > > +	} while (!time_after_eq(jiffies, timeout));
> > > +
> > > +	if (time_after_eq(jiffies, timeout)) {
> > > +		pr_err("%s timed out\n", __func__);
> > > +		return -ETIMEDOUT;
> > > +	}  
> > 
> > All of this should be done by the function calling nand_calculate_hwecc(), not here.  
> Ok, I will update it.
> > 
> > Plus, it should deserve a function on its own.  
> Ok, will add new one.
> >   
> > > +
> > > +	for (ecc_reg = 0; ecc_reg < 4; ecc_reg++) {
> > > +		/* Read ECC value for each block */  
> > 
> > So you assume here that there are 4, and only 4 "blocks" (I prefer "ECC chunks" or
> > "subpages"). Is it always the case? Or is it just how it works in your situation? I would rather
> > prefer a to define this value anyway.  
> Sure, I will define a macro as ECC chunks to represent 4.
> And there are always 4 ECC registers as per the controller. And there is no assumption here.

What about smaller or larger NAND chips? Maybe there are some
limitations in what chips are actually supported, then they should be
rejected.


[...]

> > > +static void pl353_prepare_cmd(struct mtd_info *mtd, struct
nand_chip *chip,
> > > +			      int page, int column, int start_cmd, int end_cmd,
> > > +			      bool read)
> > > +{
> > > +	unsigned long data_phase_addr;
> > > +	u32 end_cmd_valid = 0;
> > > +	unsigned long cmd_phase_addr = 0, cmd_data = 0;
> > > +
> > > +	struct pl353_nand_info *xnfc =
> > > +		container_of(chip, struct pl353_nand_info, chip);
> > > +
> > > +	end_cmd_valid = read ? 1 : 0;
> > > +
> > > +	cmd_phase_addr = (unsigned long __force)xnfc->nand_base +  
> > 
> > do you really need this cast?  
> As I said above, during command and data phases, we have to update the AXI Read/Write addresses with cycles, start command, end command
> And some extra info. Hence I am converting it to a value and then adding the above values and then again converting back as an
> Address.
> 
> >   
> > > +			 ((xnfc->addr_cycles
> > > +			 << ADDR_CYCLES_SHIFT) |
> > > +			 (end_cmd_valid << END_CMD_VALID_SHIFT) |
> > > +			 (COMMAND_PHASE) |
> > > +			 (end_cmd << END_CMD_SHIFT) |
> > > +			 (start_cmd << START_CMD_SHIFT));  
> > 
> > So the number of address cycles changes the address where you should write the address
> > cycles? that's weird, no?  
> I agree, but the implementation of PL353 is like that.
> As I pointed the spec above, for every transfer we have to frame AXI Write address and Read address.
> 
> >   
> > > +
> > > +	/* Get the data phase address */
> > > +	data_phase_addr = (unsigned long __force)xnfc->nand_base +
> > > +			  ((0x0 << CLEAR_CS_SHIFT) |
> > > +			  (0 << END_CMD_VALID_SHIFT) |
> > > +			  (DATA_PHASE) |
> > > +			  (end_cmd << END_CMD_SHIFT) |
> > > +			  (0x0 << ECC_LAST_SHIFT));
> > > +  
> > Same question here?
> >   
> > > +	xnfc->nandaddr = (void __iomem * __force)data_phase_addr;  
> > 
> > This should be done only once in the probe  
> No, as explained above, once we frame the Axi Write address/Read address with valid data, then we
> Are converting back as memory address with the casting.
> Do you see any issues with that?
> Let me know, is there an alternative to achieve the same. 
> All is about, constructing AXI Write address and Read address during command and data phases.

Ok, I'll ask Boris to also review your next version, once -rc1 is out.

Thanks,
Miquèl

RE: [LINUX PATCH v11 1/3] dt-bindings: memory: Add pl353 smc controller devicetree binding information

[Naga Sureshkumar Relli]

Hi,

[LINUX PATCH v11 1/3] dt-bindings: memory: Add pl353 smc controller devicetree binding information
[LINUX PATCH v11 2/3] memory: pl353: Add driver for arm pl353 static memory controller

Can somebody apply the above patches?
The above patches are already reviewed. 

Thanks,
Naga Sureshkumar Relli.

> -----Original Message-----
> From: Linus Walleij [mailto:linus.walleij@linaro.org]
> Sent: Friday, July 13, 2018 1:07 PM
> To: Naga Sureshkumar Relli <nagasure@xilinx.com>
> Cc: Boris Brezillon <boris.brezillon@bootlin.com>; Richard Weinberger <richard@nod.at>;
> David Woodhouse <dwmw2@infradead.org>; Brian Norris
> <computersforpeace@gmail.com>; Mark Vasut <marek.vasut@gmail.com>; Florian Fainelli
> <f.fainelli@gmail.com>; Markus Mayer <mmayer@broadcom.com>; Roger Quadros
> <rogerq@ti.com>; Ladislav Michl <ladis@linux-mips.org>; ada@thorsis.co;
> honghui.zhang@mediatek.com; Miquèl Raynal <miquel.raynal@bootlin.com>; linux-
> mtd@lists.infradead.org; linux-kernel@vger.kernel.org; nagasureshkumarrelli@gmail.com;
> Michal Simek <michals@xilinx.com>
> Subject: Re: [LINUX PATCH v11 1/3] dt-bindings: memory: Add pl353 smc controller
> devicetree binding information
> 
> On Wed, Jul 11, 2018 at 9:37 AM Naga Sureshkumar Relli
> <naga.sureshkumar.relli@xilinx.com> wrote:
> 
> > Add pl353 static memory controller devicetree binding information.
> >
> > Signed-off-by: Naga Sureshkumar Relli
> > <naga.sureshkumar.relli@xilinx.com>
> > ---
> > Changes in v11:
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Thanks!
> 
> Yours,
> Linus Walleij