[PATCH v11 1/3] dt-bindings: binding for jz4780-{nand,bch}

[PATCH v11 1/3] dt-bindings: binding for jz4780-{nand,bch}

[Harvey Hunt]

From: Alex Smith <alex.smith@imgtec.com>

Add DT bindings for NAND devices connected to the NEMC on JZ4780 SoCs,
as well as the hardware BCH controller, used by the jz4780_{nand,bch}
drivers.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: linux-mtd@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: robh@kernel.org
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
v10 -> v11:
 - Added Boris Brezillon's Reviewed-By.

v9 -> v10:
 - Added Rob Herring's Acked-by.

v8 -> v9:
 - Document that partitions are represented as a child node of a NAND chip.

v7 -> v8:
 - Describe how NAND chips are now child nodes of the NAND controller.

v6 -> v7:
 - Add nand-ecc-mode to DT bindings.
 - Add nand-on-flash-bbt to DT bindings.

v5 -> v6:
 - No change.

v4 -> v5:
 - Rename ingenic,bch-device to ingenic,bch-controller to fit with
   existing convention.

v3 -> v4:
 - No change

v2 -> v3:
 - Rebase to 4.0-rc6
 - Changed ingenic,ecc-size to common nand-ecc-step-size
 - Changed ingenic,ecc-strength to common nand-ecc-strength
 - Changed ingenic,busy-gpio to common rb-gpios
 - Changed ingenic,wp-gpio to common wp-gpios

v1 -> v2:
 - Rebase to 4.0-rc3

 .../bindings/mtd/ingenic,jz4780-nand.txt           | 86 ++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt

diff --git a/Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt b/Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt
new file mode 100644
index 0000000..29ea585
--- /dev/null
+++ b/Documentation/devicetree/bindings/mtd/ingenic,jz4780-nand.txt
@@ -0,0 +1,86 @@
+* Ingenic JZ4780 NAND/BCH
+
+This file documents the device tree bindings for NAND flash devices on the
+JZ4780. NAND devices are connected to the NEMC controller (described in
+memory-controllers/ingenic,jz4780-nemc.txt), and thus NAND device nodes must
+be children of the NEMC node.
+
+Required NAND controller device properties:
+- compatible: Should be set to "ingenic,jz4780-nand".
+- reg: For each bank with a NAND chip attached, should specify a bank number,
+  an offset of 0 and a size of 0x1000000 (i.e. the whole NEMC bank).
+
+Optional NAND controller device properties:
+- ingenic,bch-controller: To make use of the hardware BCH controller, this
+  property must contain a phandle for the BCH controller node. The required
+  properties for this node are described below. If this is not specified,
+  software BCH will be used instead.
+
+Optional children nodes:
+- Individual NAND chips are children of the NAND controller node.
+
+Required children node properties:
+- reg: An integer ranging from 1 to 6 representing the CS line to use.
+
+Optional children node properties:
+- nand-ecc-step-size: ECC block size in bytes.
+- nand-ecc-strength: ECC strength (max number of correctable bits).
+- nand-ecc-mode: String, operation mode of the NAND ecc mode. "hw" by default
+- nand-on-flash-bbt: boolean to enable on flash bbt option, if not present false
+- rb-gpios: GPIO specifier for the busy pin.
+- wp-gpios: GPIO specifier for the write protect pin.
+
+Optional child node of NAND chip nodes:
+- partitions: see Documentation/devicetree/bindings/mtd/partition.txt
+
+Example:
+
+nemc: nemc@13410000 {
+	...
+
+	nandc: nand-controller@1 {
+		compatible = "ingenic,jz4780-nand";
+		reg = <1 0 0x1000000>;	/* Bank 1 */
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ingenic,bch-controller = <&bch>;
+
+		nand@1 {
+			reg = <1>;
+
+			nand-ecc-step-size = <1024>;
+			nand-ecc-strength = <24>;
+			nand-ecc-mode = "hw";
+			nand-on-flash-bbt;
+
+			rb-gpios = <&gpa 20 GPIO_ACTIVE_LOW>;
+			wp-gpios = <&gpf 22 GPIO_ACTIVE_LOW>;
+
+			partitions {
+				#address-cells = <2>;
+				#size-cells = <2>;
+				...
+			}
+		};
+	};
+};
+
+The BCH controller is a separate SoC component used for error correction on
+NAND devices. The following is a description of the device properties for a
+BCH controller.
+
+Required BCH properties:
+- compatible: Should be set to "ingenic,jz4780-bch".
+- reg: Should specify the BCH controller registers location and length.
+- clocks: Clock for the BCH controller.
+
+Example:
+
+bch: bch@134d0000 {
+	compatible = "ingenic,jz4780-bch";
+	reg = <0x134d0000 0x10000>;
+
+	clocks = <&cgu JZ4780_CLK_BCH>;
+};
-- 
2.6.4

[PATCH v11 2/3] mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs

[Harvey Hunt]

From: Alex Smith <alex.smith@imgtec.com>

Add a driver for NAND devices connected to the NEMC on JZ4780 SoCs, as
well as the hardware BCH controller. DMA is not currently implemented.

While older 47xx SoCs also have a BCH controller, they are incompatible
with the one in the 4780 due to differing register/bit positions, which
would make implementing a common driver for them quite messy.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
v10 -> v11:
 - Reordered mutex unlocking.
 - Made jz4780_bch_get() private.
 - Removed extern prefix from function prototype definitions.
 - Removed a useless else.
 - Changed ECC strength print statement.
 - Implemented jz4780_nand_cleanup_chips().
 - Add a NAND chip to the NFC's list after it has been initialised.
 - Complain when NAND_ECC_HW_SYNDROME is selected.
 - Call jz4780_bch_release() from jz4780_nand_probe().
 - Added Boris Brezillon's Reviewed-By.

v9 -> v10:
 - Replace uint{8,32}_t with u{8,32}.
 - Only set IO_ADDR_{R,W} during chip init.
 - Check that ECC layout fits into OOB area.
 - Rebase onto l2-mtd/master and use its new functions.
 - Remove mtd field from jz4780_nand_chip.
 - Tidied up jz4780_nand_cmd_ctrl.
 - Corrected ECC mode print statement.
 - Refactor BCH code.
 - Implement of_jz4780_bch_get.
 - Update Authorship.
 - Use a mutex to protect accesses to BCH controller.
 - Update code documentation.
 - Checkpatch cleanup.

v8 -> v9:
 - No change.

v7 -> v8:
 - Rebase to 4.4-rc3.
 - Add _US suffixes to time constants.
 - Add locking to BCH hardware accesses.
 - Don't print ECC info if ECC is not being used.
 - Default to No ECC.
 - Let the NAND core handle ECC layout in certain cases.
 - Use the gpio_desc consumer interface.
 - Removed gpio active low flags.
 - Check for the BCH controller before initialising a chip.
 - Add a jz4780_nand_controller struct.
 - Initialise chips by iterating over DT child nodes. 

v6 -> v7:
 - Add nand-ecc-mode to DT bindings.
 - Add nand-on-flash-bbt to DT bindings.

v5 -> v6:
 - No change.

v4 -> v5:
 - Rename ingenic,bch-device to ingenic,bch-controller to fit with
   existing convention.

v3 -> v4:
 - No change

v2 -> v3:
 - Rebase to 4.0-rc6
 - Changed ingenic,ecc-size to common nand-ecc-step-size
 - Changed ingenic,ecc-strength to common nand-ecc-strength
 - Changed ingenic,busy-gpio to common rb-gpios
 - Changed ingenic,wp-gpio to common wp-gpios

v1 -> v2:
 - Rebase to 4.0-rc3

 drivers/mtd/nand/Kconfig       |   7 +
 drivers/mtd/nand/Makefile      |   1 +
 drivers/mtd/nand/jz4780_bch.c  | 380 +++++++++++++++++++++++++++++++++++++
 drivers/mtd/nand/jz4780_bch.h  |  43 +++++
 drivers/mtd/nand/jz4780_nand.c | 422 +++++++++++++++++++++++++++++++++++++++++
 5 files changed, 853 insertions(+)
 create mode 100644 drivers/mtd/nand/jz4780_bch.c
 create mode 100644 drivers/mtd/nand/jz4780_bch.h
 create mode 100644 drivers/mtd/nand/jz4780_nand.c

diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
index 2896640..b742adc 100644
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -519,6 +519,13 @@ config MTD_NAND_JZ4740
 	help
 		Enables support for NAND Flash on JZ4740 SoC based boards.
 
+config MTD_NAND_JZ4780
+	tristate "Support for NAND on JZ4780 SoC"
+	depends on MACH_JZ4780 && JZ4780_NEMC
+	help
+	  Enables support for NAND Flash connected to the NEMC on JZ4780 SoC
+	  based boards, using the BCH controller for hardware error correction.
+
 config MTD_NAND_FSMC
 	tristate "Support for NAND on ST Micros FSMC"
 	depends on PLAT_SPEAR || ARCH_NOMADIK || ARCH_U8500 || MACH_U300
diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
index 2c7f014..9e36233 100644
--- a/drivers/mtd/nand/Makefile
+++ b/drivers/mtd/nand/Makefile
@@ -49,6 +49,7 @@ obj-$(CONFIG_MTD_NAND_MPC5121_NFC)	+= mpc5121_nfc.o
 obj-$(CONFIG_MTD_NAND_VF610_NFC)	+= vf610_nfc.o
 obj-$(CONFIG_MTD_NAND_RICOH)		+= r852.o
 obj-$(CONFIG_MTD_NAND_JZ4740)		+= jz4740_nand.o
+obj-$(CONFIG_MTD_NAND_JZ4780)		+= jz4780_nand.o jz4780_bch.o
 obj-$(CONFIG_MTD_NAND_GPMI_NAND)	+= gpmi-nand/
 obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
 obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
diff --git a/drivers/mtd/nand/jz4780_bch.c b/drivers/mtd/nand/jz4780_bch.c
new file mode 100644
index 0000000..53b2c06
--- /dev/null
+++ b/drivers/mtd/nand/jz4780_bch.c
@@ -0,0 +1,380 @@
+/*
+ * JZ4780 BCH controller
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include "jz4780_bch.h"
+
+#define BCH_BHCR			0x0
+#define BCH_BHCCR			0x8
+#define BCH_BHCNT			0xc
+#define BCH_BHDR			0x10
+#define BCH_BHPAR0			0x14
+#define BCH_BHERR0			0x84
+#define BCH_BHINT			0x184
+#define BCH_BHINTES			0x188
+#define BCH_BHINTEC			0x18c
+#define BCH_BHINTE			0x190
+
+#define BCH_BHCR_BSEL_SHIFT		4
+#define BCH_BHCR_BSEL_MASK		(0x7f << BCH_BHCR_BSEL_SHIFT)
+#define BCH_BHCR_ENCE			BIT(2)
+#define BCH_BHCR_INIT			BIT(1)
+#define BCH_BHCR_BCHE			BIT(0)
+
+#define BCH_BHCNT_PARITYSIZE_SHIFT	16
+#define BCH_BHCNT_PARITYSIZE_MASK	(0x7f << BCH_BHCNT_PARITYSIZE_SHIFT)
+#define BCH_BHCNT_BLOCKSIZE_SHIFT	0
+#define BCH_BHCNT_BLOCKSIZE_MASK	(0x7ff << BCH_BHCNT_BLOCKSIZE_SHIFT)
+
+#define BCH_BHERR_MASK_SHIFT		16
+#define BCH_BHERR_MASK_MASK		(0xffff << BCH_BHERR_MASK_SHIFT)
+#define BCH_BHERR_INDEX_SHIFT		0
+#define BCH_BHERR_INDEX_MASK		(0x7ff << BCH_BHERR_INDEX_SHIFT)
+
+#define BCH_BHINT_ERRC_SHIFT		24
+#define BCH_BHINT_ERRC_MASK		(0x7f << BCH_BHINT_ERRC_SHIFT)
+#define BCH_BHINT_TERRC_SHIFT		16
+#define BCH_BHINT_TERRC_MASK		(0x7f << BCH_BHINT_TERRC_SHIFT)
+#define BCH_BHINT_DECF			BIT(3)
+#define BCH_BHINT_ENCF			BIT(2)
+#define BCH_BHINT_UNCOR			BIT(1)
+#define BCH_BHINT_ERR			BIT(0)
+
+#define BCH_CLK_RATE			(200 * 1000 * 1000)
+
+/* Timeout for BCH calculation/correction. */
+#define BCH_TIMEOUT_US			100000
+
+struct jz4780_bch {
+	struct device *dev;
+	void __iomem *base;
+	struct clk *clk;
+	struct mutex lock;
+};
+
+static void jz4780_bch_init(struct jz4780_bch *bch,
+			    struct jz4780_bch_params *params, bool encode)
+{
+	u32 reg;
+
+	/* Clear interrupt status. */
+	writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);
+
+	/* Set up BCH count register. */
+	reg = params->size << BCH_BHCNT_BLOCKSIZE_SHIFT;
+	reg |= params->bytes << BCH_BHCNT_PARITYSIZE_SHIFT;
+	writel(reg, bch->base + BCH_BHCNT);
+
+	/* Initialise and enable BCH. */
+	reg = BCH_BHCR_BCHE | BCH_BHCR_INIT;
+	reg |= params->strength << BCH_BHCR_BSEL_SHIFT;
+	if (encode)
+		reg |= BCH_BHCR_ENCE;
+	writel(reg, bch->base + BCH_BHCR);
+}
+
+static void jz4780_bch_disable(struct jz4780_bch *bch)
+{
+	writel(readl(bch->base + BCH_BHINT), bch->base + BCH_BHINT);
+	writel(BCH_BHCR_BCHE, bch->base + BCH_BHCCR);
+}
+
+static void jz4780_bch_write_data(struct jz4780_bch *bch, const void *buf,
+				  size_t size)
+{
+	size_t size32 = size / sizeof(u32);
+	size_t size8 = size % sizeof(u32);
+	const u32 *src32;
+	const u8 *src8;
+
+	src32 = (const u32 *)buf;
+	while (size32--)
+		writel(*src32++, bch->base + BCH_BHDR);
+
+	src8 = (const u8 *)src32;
+	while (size8--)
+		writeb(*src8++, bch->base + BCH_BHDR);
+}
+
+static void jz4780_bch_read_parity(struct jz4780_bch *bch, void *buf,
+				   size_t size)
+{
+	size_t size32 = size / sizeof(u32);
+	size_t size8 = size % sizeof(u32);
+	u32 *dest32;
+	u8 *dest8;
+	u32 val, offset = 0;
+
+	dest32 = (u32 *)buf;
+	while (size32--) {
+		*dest32++ = readl(bch->base + BCH_BHPAR0 + offset);
+		offset += sizeof(u32);
+	}
+
+	dest8 = (u8 *)dest32;
+	val = readl(bch->base + BCH_BHPAR0 + offset);
+	switch (size8) {
+	case 3:
+		dest8[2] = (val >> 16) & 0xff;
+	case 2:
+		dest8[1] = (val >> 8) & 0xff;
+	case 1:
+		dest8[0] = val & 0xff;
+		break;
+	}
+}
+
+static bool jz4780_bch_wait_complete(struct jz4780_bch *bch, unsigned int irq,
+				     u32 *status)
+{
+	u32 reg;
+	int ret;
+
+	/*
+	 * While we could use interrupts here and sleep until the operation
+	 * completes, the controller works fairly quickly (usually a few
+	 * microseconds) and so the overhead of sleeping until we get an
+	 * interrupt quite noticeably decreases performance.
+	 */
+	ret = readl_poll_timeout(bch->base + BCH_BHINT, reg,
+				 (reg & irq) == irq, 0, BCH_TIMEOUT_US);
+	if (ret)
+		return false;
+
+	if (status)
+		*status = reg;
+
+	writel(reg, bch->base + BCH_BHINT);
+	return true;
+}
+
+/**
+ * jz4780_bch_calculate() - calculate ECC for a data buffer
+ * @bch: BCH device.
+ * @params: BCH parameters.
+ * @buf: input buffer with raw data.
+ * @ecc_code: output buffer with ECC.
+ *
+ * Return: 0 on success, -ETIMEDOUT if timed out while waiting for BCH
+ * controller.
+ */
+int jz4780_bch_calculate(struct jz4780_bch *bch, struct jz4780_bch_params *params,
+			 const u8 *buf, u8 *ecc_code)
+{
+	int ret = 0;
+
+	mutex_lock(&bch->lock);
+	jz4780_bch_init(bch, params, true);
+	jz4780_bch_write_data(bch, buf, params->size);
+
+	if (jz4780_bch_wait_complete(bch, BCH_BHINT_ENCF, NULL)) {
+		jz4780_bch_read_parity(bch, ecc_code, params->bytes);
+	} else {
+		dev_err(bch->dev, "timed out while calculating ECC\n");
+		ret = -ETIMEDOUT;
+	}
+
+	jz4780_bch_disable(bch);
+	mutex_unlock(&bch->lock);
+	return ret;
+}
+EXPORT_SYMBOL(jz4780_bch_calculate);
+
+/**
+ * jz4780_bch_correct() - detect and correct bit errors
+ * @bch: BCH device.
+ * @params: BCH parameters.
+ * @buf: raw data read from the chip.
+ * @ecc_code: ECC read from the chip.
+ *
+ * Given the raw data and the ECC read from the NAND device, detects and
+ * corrects errors in the data.
+ *
+ * Return: the number of bit errors corrected, or -1 if there are too many
+ * errors to correct or we timed out waiting for the controller.
+ */
+int jz4780_bch_correct(struct jz4780_bch *bch, struct jz4780_bch_params *params,
+		       u8 *buf, u8 *ecc_code)
+{
+	u32 reg, mask, index;
+	int i, ret, count;
+
+	mutex_lock(&bch->lock);
+
+	jz4780_bch_init(bch, params, false);
+	jz4780_bch_write_data(bch, buf, params->size);
+	jz4780_bch_write_data(bch, ecc_code, params->bytes);
+
+	if (!jz4780_bch_wait_complete(bch, BCH_BHINT_DECF, &reg)) {
+		dev_err(bch->dev, "timed out while correcting data\n");
+		ret = -1;
+		goto out;
+	}
+
+	if (reg & BCH_BHINT_UNCOR) {
+		dev_warn(bch->dev, "uncorrectable ECC error\n");
+		ret = -1;
+		goto out;
+	}
+
+	/* Correct any detected errors. */
+	if (reg & BCH_BHINT_ERR) {
+		count = (reg & BCH_BHINT_ERRC_MASK) >> BCH_BHINT_ERRC_SHIFT;
+		ret = (reg & BCH_BHINT_TERRC_MASK) >> BCH_BHINT_TERRC_SHIFT;
+
+		for (i = 0; i < count; i++) {
+			reg = readl(bch->base + BCH_BHERR0 + (i * 4));
+			mask = (reg & BCH_BHERR_MASK_MASK) >>
+						BCH_BHERR_MASK_SHIFT;
+			index = (reg & BCH_BHERR_INDEX_MASK) >>
+						BCH_BHERR_INDEX_SHIFT;
+			buf[(index * 2) + 0] ^= mask;
+			buf[(index * 2) + 1] ^= mask >> 8;
+		}
+	} else {
+		ret = 0;
+	}
+
+out:
+	jz4780_bch_disable(bch);
+	mutex_unlock(&bch->lock);
+	return ret;
+}
+EXPORT_SYMBOL(jz4780_bch_correct);
+
+/**
+ * jz4780_bch_get() - get the BCH controller device
+ * @np: BCH device tree node.
+ *
+ * Gets the BCH controller device from the specified device tree node. The
+ * device must be released with jz4780_bch_release() when it is no longer being
+ * used.
+ *
+ * Return: a pointer to jz4780_bch, errors are encoded into the pointer.
+ * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
+ */
+static struct jz4780_bch *jz4780_bch_get(struct device_node *np)
+{
+	struct platform_device *pdev;
+	struct jz4780_bch *bch;
+
+	pdev = of_find_device_by_node(np);
+	if (!pdev || !platform_get_drvdata(pdev))
+		return ERR_PTR(-EPROBE_DEFER);
+
+	get_device(&pdev->dev);
+
+	bch = platform_get_drvdata(pdev);
+	clk_prepare_enable(bch->clk);
+
+	bch->dev = &pdev->dev;
+	return bch;
+}
+
+/**
+ * of_jz4780_bch_get() - get the BCH controller from a DT node
+ * @of_node: the node that contains a bch-controller property.
+ *
+ * Get the bch-controller property from the given device tree
+ * node and pass it to jz4780_bch_get to do the work.
+ *
+ * Return: a pointer to jz4780_bch, errors are encoded into the pointer.
+ * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
+ */
+struct jz4780_bch *of_jz4780_bch_get(struct device_node *of_node)
+{
+	struct jz4780_bch *bch = NULL;
+	struct device_node *np;
+
+	np = of_parse_phandle(of_node, "ingenic,bch-controller", 0);
+
+	if (np) {
+		bch = jz4780_bch_get(np);
+		of_node_put(np);
+	}
+	return bch;
+}
+
+/**
+ * jz4780_bch_release() - release the BCH controller device
+ * @bch: BCH device.
+ */
+void jz4780_bch_release(struct jz4780_bch *bch)
+{
+	clk_disable_unprepare(bch->clk);
+	put_device(bch->dev);
+}
+EXPORT_SYMBOL(jz4780_bch_release);
+
+static int jz4780_bch_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct jz4780_bch *bch;
+	struct resource *res;
+
+	bch = devm_kzalloc(dev, sizeof(*bch), GFP_KERNEL);
+	if (!bch)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	bch->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(bch->base))
+		return PTR_ERR(bch->base);
+
+	jz4780_bch_disable(bch);
+
+	bch->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(bch->clk)) {
+		dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(bch->clk));
+		return PTR_ERR(bch->clk);
+	}
+
+	clk_set_rate(bch->clk, BCH_CLK_RATE);
+
+	mutex_init(&bch->lock);
+
+	bch->dev = dev;
+	platform_set_drvdata(pdev, bch);
+
+	return 0;
+}
+
+static const struct of_device_id jz4780_bch_dt_match[] = {
+	{ .compatible = "ingenic,jz4780-bch" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, jz4780_bch_dt_match);
+
+static struct platform_driver jz4780_bch_driver = {
+	.probe		= jz4780_bch_probe,
+	.driver	= {
+		.name	= "jz4780-bch",
+		.of_match_table = of_match_ptr(jz4780_bch_dt_match),
+	},
+};
+module_platform_driver(jz4780_bch_driver);
+
+MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
+MODULE_AUTHOR("Harvey Hunt <harvey.hunt@imgtec.com>");
+MODULE_DESCRIPTION("Ingenic JZ4780 BCH error correction driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/mtd/nand/jz4780_bch.h b/drivers/mtd/nand/jz4780_bch.h
new file mode 100644
index 0000000..bf471808
--- /dev/null
+++ b/drivers/mtd/nand/jz4780_bch.h
@@ -0,0 +1,43 @@
+/*
+ * JZ4780 BCH controller
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#ifndef __DRIVERS_MTD_NAND_JZ4780_BCH_H__
+#define __DRIVERS_MTD_NAND_JZ4780_BCH_H__
+
+#include <linux/types.h>
+
+struct device;
+struct device_node;
+struct jz4780_bch;
+
+/**
+ * struct jz4780_bch_params - BCH parameters
+ * @size: data bytes per ECC step.
+ * @bytes: ECC bytes per step.
+ * @strength: number of correctable bits per ECC step.
+ */
+struct jz4780_bch_params {
+	int size;
+	int bytes;
+	int strength;
+};
+
+int jz4780_bch_calculate(struct jz4780_bch *bch,
+				struct jz4780_bch_params *params,
+				const u8 *buf, u8 *ecc_code);
+int jz4780_bch_correct(struct jz4780_bch *bch,
+			      struct jz4780_bch_params *params, u8 *buf,
+			      u8 *ecc_code);
+
+void jz4780_bch_release(struct jz4780_bch *bch);
+struct jz4780_bch *of_jz4780_bch_get(struct device_node *np);
+
+#endif /* __DRIVERS_MTD_NAND_JZ4780_BCH_H__ */
diff --git a/drivers/mtd/nand/jz4780_nand.c b/drivers/mtd/nand/jz4780_nand.c
new file mode 100644
index 0000000..d8ea35e
--- /dev/null
+++ b/drivers/mtd/nand/jz4780_nand.c
@@ -0,0 +1,422 @@
+/*
+ * JZ4780 NAND driver
+ *
+ * Copyright (c) 2015 Imagination Technologies
+ * Author: Alex Smith <alex.smith@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of_mtd.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+
+#include <linux/jz4780-nemc.h>
+
+#include "jz4780_bch.h"
+
+#define DRV_NAME	"jz4780-nand"
+
+#define OFFSET_DATA	0x00000000
+#define OFFSET_CMD	0x00400000
+#define OFFSET_ADDR	0x00800000
+
+/* Command delay when there is no R/B pin. */
+#define RB_DELAY_US	100
+
+struct jz4780_nand_cs {
+	unsigned int bank;
+	void __iomem *base;
+};
+
+struct jz4780_nand_controller {
+	struct device *dev;
+	struct jz4780_bch *bch;
+	struct nand_hw_control controller;
+	unsigned int num_banks;
+	struct list_head chips;
+	int selected;
+	struct jz4780_nand_cs cs[];
+};
+
+struct jz4780_nand_chip {
+	struct nand_chip chip;
+	struct list_head chip_list;
+
+	struct nand_ecclayout ecclayout;
+
+	struct gpio_desc *busy_gpio;
+	struct gpio_desc *wp_gpio;
+	unsigned int reading: 1;
+};
+
+static inline struct jz4780_nand_chip *to_jz4780_nand_chip(struct mtd_info *mtd)
+{
+	return container_of(mtd_to_nand(mtd), struct jz4780_nand_chip, chip);
+}
+
+static inline struct jz4780_nand_controller *to_jz4780_nand_controller(struct nand_hw_control *ctrl)
+{
+	return container_of(ctrl, struct jz4780_nand_controller, controller);
+}
+
+static void jz4780_nand_select_chip(struct mtd_info *mtd, int chipnr)
+{
+	struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
+	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
+	struct jz4780_nand_cs *cs;
+
+	/* Ensure the currently selected chip is deasserted. */
+	if (chipnr == -1 && nfc->selected >= 0) {
+		cs = &nfc->cs[nfc->selected];
+		jz4780_nemc_assert(nfc->dev, cs->bank, false);
+	}
+
+	nfc->selected = chipnr;
+}
+
+static void jz4780_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
+				 unsigned int ctrl)
+{
+	struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
+	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
+	struct jz4780_nand_cs *cs;
+
+	if (WARN_ON(nfc->selected < 0))
+		return;
+
+	cs = &nfc->cs[nfc->selected];
+
+	jz4780_nemc_assert(nfc->dev, cs->bank, ctrl & NAND_NCE);
+
+	if (cmd == NAND_CMD_NONE)
+		return;
+
+	if (ctrl & NAND_ALE)
+		writeb(cmd, cs->base + OFFSET_ADDR);
+	else if (ctrl & NAND_CLE)
+		writeb(cmd, cs->base + OFFSET_CMD);
+}
+
+static int jz4780_nand_dev_ready(struct mtd_info *mtd)
+{
+	struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
+
+	return !gpiod_get_value_cansleep(nand->busy_gpio);
+}
+
+static void jz4780_nand_ecc_hwctl(struct mtd_info *mtd, int mode)
+{
+	struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
+
+	nand->reading = (mode == NAND_ECC_READ);
+}
+
+static int jz4780_nand_ecc_calculate(struct mtd_info *mtd, const u8 *dat,
+				     u8 *ecc_code)
+{
+	struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
+	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
+	struct jz4780_bch_params params;
+
+	/*
+	 * Don't need to generate the ECC when reading, BCH does it for us as
+	 * part of decoding/correction.
+	 */
+	if (nand->reading)
+		return 0;
+
+	params.size = nand->chip.ecc.size;
+	params.bytes = nand->chip.ecc.bytes;
+	params.strength = nand->chip.ecc.strength;
+
+	return jz4780_bch_calculate(nfc->bch, &params, dat, ecc_code);
+}
+
+static int jz4780_nand_ecc_correct(struct mtd_info *mtd, u8 *dat,
+				   u8 *read_ecc, u8 *calc_ecc)
+{
+	struct jz4780_nand_chip *nand = to_jz4780_nand_chip(mtd);
+	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(nand->chip.controller);
+	struct jz4780_bch_params params;
+
+	params.size = nand->chip.ecc.size;
+	params.bytes = nand->chip.ecc.bytes;
+	params.strength = nand->chip.ecc.strength;
+
+	return jz4780_bch_correct(nfc->bch, &params, dat, read_ecc);
+}
+
+static int jz4780_nand_init_ecc(struct jz4780_nand_chip *nand, struct device *dev)
+{
+	struct nand_chip *chip = &nand->chip;
+	struct mtd_info *mtd = nand_to_mtd(chip);
+	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(chip->controller);
+	struct nand_ecclayout *layout = &nand->ecclayout;
+	u32 start, i;
+
+	chip->ecc.bytes = fls((1 + 8) * chip->ecc.size)	*
+				(chip->ecc.strength / 8);
+
+	if (nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
+		chip->ecc.hwctl = jz4780_nand_ecc_hwctl;
+		chip->ecc.calculate = jz4780_nand_ecc_calculate;
+		chip->ecc.correct = jz4780_nand_ecc_correct;
+	} else if (!nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
+		dev_err(dev, "HW BCH selected, but BCH controller not found\n");
+		return -ENODEV;
+	}
+
+	if (chip->ecc.mode == NAND_ECC_HW_SYNDROME) {
+		dev_err(dev, "ECC HW syndrome not supported\n");
+		return -EINVAL;
+	}
+
+	if (chip->ecc.mode != NAND_ECC_NONE)
+		dev_info(dev, "using %s (strength %d, size %d, bytes %d)\n",
+			(nfc->bch) ? "hardware BCH" : "software ECC",
+			chip->ecc.strength, chip->ecc.size, chip->ecc.bytes);
+	else
+		dev_info(dev, "not using ECC\n");
+
+	/* The NAND core will generate the ECC layout. */
+	if (chip->ecc.mode == NAND_ECC_SOFT || chip->ecc.mode == NAND_ECC_SOFT_BCH)
+		return 0;
+
+	/* Generate ECC layout. ECC codes are right aligned in the OOB area. */
+	layout->eccbytes = mtd->writesize / chip->ecc.size * chip->ecc.bytes;
+
+	if (layout->eccbytes > mtd->oobsize - 2) {
+		dev_err(dev,
+			"invalid ECC config: required %d ECC bytes, but only %d are available",
+			layout->eccbytes, mtd->oobsize - 2);
+		return -EINVAL;
+	}
+
+	start = mtd->oobsize - layout->eccbytes;
+	for (i = 0; i < layout->eccbytes; i++)
+		layout->eccpos[i] = start + i;
+
+	layout->oobfree[0].offset = 2;
+	layout->oobfree[0].length = mtd->oobsize - layout->eccbytes - 2;
+
+	chip->ecc.layout = layout;
+	return 0;
+}
+
+static int jz4780_nand_init_chip(struct platform_device *pdev,
+				struct jz4780_nand_controller *nfc,
+				struct device_node *np,
+				unsigned int chipnr)
+{
+	struct device *dev = &pdev->dev;
+	struct jz4780_nand_chip *nand;
+	struct jz4780_nand_cs *cs;
+	struct resource *res;
+	struct nand_chip *chip;
+	struct mtd_info *mtd;
+	const __be32 *reg;
+	int ret = 0;
+
+	cs = &nfc->cs[chipnr];
+
+	reg = of_get_property(np, "reg", NULL);
+	if (!reg)
+		return -EINVAL;
+
+	cs->bank = be32_to_cpu(*reg);
+
+	jz4780_nemc_set_type(nfc->dev, cs->bank, JZ4780_NEMC_BANK_NAND);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, chipnr);
+	cs->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cs->base))
+		return PTR_ERR(cs->base);
+
+	nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
+	if (!nand)
+		return -ENOMEM;
+
+	nand->busy_gpio = devm_gpiod_get_optional(dev, "rb", GPIOD_IN);
+
+	if (IS_ERR(nand->busy_gpio)) {
+		ret = PTR_ERR(nand->busy_gpio);
+		dev_err(dev, "failed to request busy GPIO: %d\n", ret);
+		return ret;
+	} else if (nand->busy_gpio) {
+		nand->chip.dev_ready = jz4780_nand_dev_ready;
+	}
+
+	nand->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_LOW);
+
+	if (IS_ERR(nand->wp_gpio)) {
+		ret = PTR_ERR(nand->wp_gpio);
+		dev_err(dev, "failed to request WP GPIO: %d\n", ret);
+		return ret;
+	}
+
+	chip = &nand->chip;
+	mtd = nand_to_mtd(chip);
+	mtd->priv = chip;
+	mtd->owner = THIS_MODULE;
+	mtd->name = DRV_NAME;
+	mtd->dev.parent = dev;
+
+	chip->IO_ADDR_R = cs->base + OFFSET_DATA;
+	chip->IO_ADDR_W = cs->base + OFFSET_DATA;
+	chip->chip_delay = RB_DELAY_US;
+	chip->options = NAND_NO_SUBPAGE_WRITE;
+	chip->select_chip = jz4780_nand_select_chip;
+	chip->cmd_ctrl = jz4780_nand_cmd_ctrl;
+	chip->ecc.mode = NAND_ECC_HW;
+	chip->controller = &nfc->controller;
+	nand_set_flash_node(chip, np);
+
+	ret = nand_scan_ident(mtd, 1, NULL);
+	if (ret)
+		return ret;
+
+	ret = jz4780_nand_init_ecc(nand, dev);
+	if (ret)
+		return ret;
+
+	ret = nand_scan_tail(mtd);
+	if (ret)
+		return ret;
+
+	ret = mtd_device_register(mtd, NULL, 0);
+	if (ret) {
+		nand_release(mtd);
+		return ret;
+	}
+
+	list_add_tail(&nand->chip_list, &nfc->chips);
+
+	return 0;
+}
+
+static void jz4780_nand_cleanup_chips(struct jz4780_nand_controller *nfc)
+{
+	struct jz4780_nand_chip *chip;
+
+	while (!list_empty(&nfc->chips)) {
+		chip = list_first_entry(&nfc->chips, struct jz4780_nand_chip, chip_list);
+		nand_release(nand_to_mtd(&chip->chip));
+		list_del(&chip->chip_list);
+	}
+}
+
+static int jz4780_nand_init_chips(struct jz4780_nand_controller *nfc,
+				  struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np;
+	int i = 0;
+	int ret;
+	int num_chips = of_get_child_count(dev->of_node);
+
+	if (num_chips > nfc->num_banks) {
+		dev_err(dev, "found %d chips but only %d banks\n", num_chips, nfc->num_banks);
+		return -EINVAL;
+	}
+
+	for_each_child_of_node(dev->of_node, np) {
+		ret = jz4780_nand_init_chip(pdev, nfc, np, i);
+		if (ret) {
+			jz4780_nand_cleanup_chips(nfc);
+			return ret;
+		}
+
+		i++;
+	}
+
+	return 0;
+}
+
+static int jz4780_nand_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	unsigned int num_banks;
+	struct jz4780_nand_controller *nfc;
+	int ret;
+
+	num_banks = jz4780_nemc_num_banks(dev);
+	if (num_banks == 0) {
+		dev_err(dev, "no banks found\n");
+		return -ENODEV;
+	}
+
+	nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
+	if (!nfc)
+		return -ENOMEM;
+
+	/*
+	 * Check for BCH HW before we call nand_scan_ident, to prevent us from
+	 * having to call it again if the BCH driver returns -EPROBE_DEFER.
+	 */
+	nfc->bch = of_jz4780_bch_get(dev->of_node);
+	if (IS_ERR(nfc->bch))
+		return PTR_ERR(nfc->bch);
+
+	nfc->dev = dev;
+	nfc->num_banks = num_banks;
+
+	spin_lock_init(&nfc->controller.lock);
+	INIT_LIST_HEAD(&nfc->chips);
+	init_waitqueue_head(&nfc->controller.wq);
+
+	ret = jz4780_nand_init_chips(nfc, pdev);
+	if (ret)
+		if (nfc->bch)
+			jz4780_bch_release(nfc->bch);
+		return ret;
+
+	platform_set_drvdata(pdev, nfc);
+	return 0;
+}
+
+static int jz4780_nand_remove(struct platform_device *pdev)
+{
+	struct jz4780_nand_controller *nfc = platform_get_drvdata(pdev);
+
+	if (nfc->bch)
+		jz4780_bch_release(nfc->bch);
+
+	jz4780_nand_cleanup_chips(nfc);
+
+	return 0;
+}
+
+static const struct of_device_id jz4780_nand_dt_match[] = {
+	{ .compatible = "ingenic,jz4780-nand" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
+
+static struct platform_driver jz4780_nand_driver = {
+	.probe		= jz4780_nand_probe,
+	.remove		= jz4780_nand_remove,
+	.driver	= {
+		.name	= DRV_NAME,
+		.of_match_table = of_match_ptr(jz4780_nand_dt_match),
+	},
+};
+module_platform_driver(jz4780_nand_driver);
+
+MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
+MODULE_AUTHOR("Harvey Hunt <harvey.hunt@imgtec.com>");
+MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
+MODULE_LICENSE("GPL v2");
-- 
2.6.4

[PATCH v11 3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes

[Harvey Hunt]

From: Alex Smith <alex.smith@imgtec.com>

Add device tree nodes for the NEMC and BCH to the JZ4780 device tree,
and make use of them in the Ci20 device tree to add a node for the
board's NAND.

Note that since the pinctrl driver is not yet upstream, this includes
neither pin configuration nor busy/write-protect GPIO pins for the
NAND. Use of the NAND relies on the boot loader to have left the pins
configured in a usable state, which should be the case when booted
from the NAND.

Signed-off-by: Alex Smith <alex.smith@imgtec.com>
Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mtd@lists.infradead.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Cc: robh@kernel.org
Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
---
v10 -> v11:
 - Added Boris Brezillon's Reviewed-By.

v9 -> v10:
 - No change.

v8 -> v9:
 - Represent the partition table as a subnode of a NAND chip. 

v7 -> v8:
 - Describe the NAND chips as children nodes of the NAND controller.
 - Remove ingenic, prefix from ECC settings.
 - Renamed some ECC settings.

v6 -> v7:
 - Add nand-ecc-mode to DT.
 - Add nand-on-flash-bbt to DT.

v4 -> v5:
 - New patch adding DT nodes for the NAND so that the driver can be
   tested.

 arch/mips/boot/dts/ingenic/ci20.dts    | 63 ++++++++++++++++++++++++++++++++++
 arch/mips/boot/dts/ingenic/jz4780.dtsi | 26 ++++++++++++++
 2 files changed, 89 insertions(+)

diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
index 9fcb9e7..782258c 100644
--- a/arch/mips/boot/dts/ingenic/ci20.dts
+++ b/arch/mips/boot/dts/ingenic/ci20.dts
@@ -42,3 +42,66 @@
 &uart4 {
 	status = "okay";
 };
+
+&nemc {
+	status = "okay";
+
+	nandc: nand-controller@1 {
+		compatible = "ingenic,jz4780-nand";
+		reg = <1 0 0x1000000>;
+
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		ingenic,bch-controller = <&bch>;
+
+		ingenic,nemc-tAS = <10>;
+		ingenic,nemc-tAH = <5>;
+		ingenic,nemc-tBP = <10>;
+		ingenic,nemc-tAW = <15>;
+		ingenic,nemc-tSTRV = <100>;
+
+		nand@1 {
+			reg = <1>;
+
+			nand-ecc-step-size = <1024>;
+			nand-ecc-strength = <24>;
+			nand-ecc-mode = "hw";
+			nand-on-flash-bbt;
+
+			partitions {
+				#address-cells = <2>;
+				#size-cells = <2>;
+
+				partition@0 {
+					label = "u-boot-spl";
+					reg = <0x0 0x0 0x0 0x800000>;
+				};
+
+				partition@0x800000 {
+					label = "u-boot";
+					reg = <0x0 0x800000 0x0 0x200000>;
+				};
+
+				partition@0xa00000 {
+					label = "u-boot-env";
+					reg = <0x0 0xa00000 0x0 0x200000>;
+				};
+
+				partition@0xc00000 {
+					label = "boot";
+					reg = <0x0 0xc00000 0x0 0x4000000>;
+				};
+
+				partition@0x8c00000 {
+					label = "system";
+					reg = <0x0 0x4c00000 0x1 0xfb400000>;
+				};
+			};
+		};
+	};
+};
+
+&bch {
+	status = "okay";
+};
diff --git a/arch/mips/boot/dts/ingenic/jz4780.dtsi b/arch/mips/boot/dts/ingenic/jz4780.dtsi
index 65389f6..b868b42 100644
--- a/arch/mips/boot/dts/ingenic/jz4780.dtsi
+++ b/arch/mips/boot/dts/ingenic/jz4780.dtsi
@@ -108,4 +108,30 @@
 
 		status = "disabled";
 	};
+
+	nemc: nemc@13410000 {
+		compatible = "ingenic,jz4780-nemc";
+		reg = <0x13410000 0x10000>;
+		#address-cells = <2>;
+		#size-cells = <1>;
+		ranges = <1 0 0x1b000000 0x1000000
+			  2 0 0x1a000000 0x1000000
+			  3 0 0x19000000 0x1000000
+			  4 0 0x18000000 0x1000000
+			  5 0 0x17000000 0x1000000
+			  6 0 0x16000000 0x1000000>;
+
+		clocks = <&cgu JZ4780_CLK_NEMC>;
+
+		status = "disabled";
+	};
+
+	bch: bch@134d0000 {
+		compatible = "ingenic,jz4780-bch";
+		reg = <0x134d0000 0x10000>;
+
+		clocks = <&cgu JZ4780_CLK_BCH>;
+
+		status = "disabled";
+	};
 };
-- 
2.6.4

Re: [PATCH v11 2/3] mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs

[Brian Norris]

Hi Harvey,

On Mon, Jan 04, 2016 at 12:34:43PM +0000, Harvey Hunt wrote:
> From: Alex Smith <alex.smith@imgtec.com>
> 
> Add a driver for NAND devices connected to the NEMC on JZ4780 SoCs, as
> well as the hardware BCH controller. DMA is not currently implemented.
> 
> While older 47xx SoCs also have a BCH controller, they are incompatible
> with the one in the 4780 due to differing register/bit positions, which
> would make implementing a common driver for them quite messy.
> 
> Signed-off-by: Alex Smith <alex.smith@imgtec.com>
> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Brian Norris <computersforpeace@gmail.com>
> Cc: linux-mtd@lists.infradead.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
[...]

>  drivers/mtd/nand/Kconfig       |   7 +
>  drivers/mtd/nand/Makefile      |   1 +
>  drivers/mtd/nand/jz4780_bch.c  | 380 +++++++++++++++++++++++++++++++++++++
>  drivers/mtd/nand/jz4780_bch.h  |  43 +++++
>  drivers/mtd/nand/jz4780_nand.c | 422 +++++++++++++++++++++++++++++++++++++++++
>  5 files changed, 853 insertions(+)
>  create mode 100644 drivers/mtd/nand/jz4780_bch.c
>  create mode 100644 drivers/mtd/nand/jz4780_bch.h
>  create mode 100644 drivers/mtd/nand/jz4780_nand.c
> 
> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
> index 2896640..b742adc 100644
> --- a/drivers/mtd/nand/Kconfig
> +++ b/drivers/mtd/nand/Kconfig
> @@ -519,6 +519,13 @@ config MTD_NAND_JZ4740
>  	help
>  		Enables support for NAND Flash on JZ4740 SoC based boards.
>  
> +config MTD_NAND_JZ4780
> +	tristate "Support for NAND on JZ4780 SoC"
> +	depends on MACH_JZ4780 && JZ4780_NEMC
> +	help
> +	  Enables support for NAND Flash connected to the NEMC on JZ4780 SoC
> +	  based boards, using the BCH controller for hardware error correction.
> +
>  config MTD_NAND_FSMC
>  	tristate "Support for NAND on ST Micros FSMC"
>  	depends on PLAT_SPEAR || ARCH_NOMADIK || ARCH_U8500 || MACH_U300
> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
> index 2c7f014..9e36233 100644
> --- a/drivers/mtd/nand/Makefile
> +++ b/drivers/mtd/nand/Makefile
> @@ -49,6 +49,7 @@ obj-$(CONFIG_MTD_NAND_MPC5121_NFC)	+= mpc5121_nfc.o
>  obj-$(CONFIG_MTD_NAND_VF610_NFC)	+= vf610_nfc.o
>  obj-$(CONFIG_MTD_NAND_RICOH)		+= r852.o
>  obj-$(CONFIG_MTD_NAND_JZ4740)		+= jz4740_nand.o
> +obj-$(CONFIG_MTD_NAND_JZ4780)		+= jz4780_nand.o jz4780_bch.o
>  obj-$(CONFIG_MTD_NAND_GPMI_NAND)	+= gpmi-nand/
>  obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
>  obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
> diff --git a/drivers/mtd/nand/jz4780_bch.c b/drivers/mtd/nand/jz4780_bch.c
> new file mode 100644
> index 0000000..53b2c06
> --- /dev/null
> +++ b/drivers/mtd/nand/jz4780_bch.c
> @@ -0,0 +1,380 @@

[...]

> +/**
> + * of_jz4780_bch_get() - get the BCH controller from a DT node
> + * @of_node: the node that contains a bch-controller property.
> + *
> + * Get the bch-controller property from the given device tree
> + * node and pass it to jz4780_bch_get to do the work.
> + *
> + * Return: a pointer to jz4780_bch, errors are encoded into the pointer.
> + * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
> + */
> +struct jz4780_bch *of_jz4780_bch_get(struct device_node *of_node)
> +{
> +	struct jz4780_bch *bch = NULL;
> +	struct device_node *np;
> +
> +	np = of_parse_phandle(of_node, "ingenic,bch-controller", 0);
> +
> +	if (np) {
> +		bch = jz4780_bch_get(np);
> +		of_node_put(np);
> +	}
> +	return bch;
> +}

Don't you need to EXPORT_SYMBOL() this one?

[...]

> diff --git a/drivers/mtd/nand/jz4780_bch.h b/drivers/mtd/nand/jz4780_bch.h
> new file mode 100644
> index 0000000..bf471808
> --- /dev/null
> +++ b/drivers/mtd/nand/jz4780_bch.h
> @@ -0,0 +1,43 @@
> +/*
> + * JZ4780 BCH controller
> + *
> + * Copyright (c) 2015 Imagination Technologies
> + * Author: Alex Smith <alex.smith@imgtec.com>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published
> + * by the Free Software Foundation.
> + */
> +
> +#ifndef __DRIVERS_MTD_NAND_JZ4780_BCH_H__
> +#define __DRIVERS_MTD_NAND_JZ4780_BCH_H__
> +
> +#include <linux/types.h>
> +
> +struct device;
> +struct device_node;
> +struct jz4780_bch;
> +
> +/**
> + * struct jz4780_bch_params - BCH parameters
> + * @size: data bytes per ECC step.
> + * @bytes: ECC bytes per step.
> + * @strength: number of correctable bits per ECC step.
> + */
> +struct jz4780_bch_params {
> +	int size;
> +	int bytes;
> +	int strength;
> +};
> +
> +int jz4780_bch_calculate(struct jz4780_bch *bch,
> +				struct jz4780_bch_params *params,
> +				const u8 *buf, u8 *ecc_code);
> +int jz4780_bch_correct(struct jz4780_bch *bch,
> +			      struct jz4780_bch_params *params, u8 *buf,
> +			      u8 *ecc_code);
> +
> +void jz4780_bch_release(struct jz4780_bch *bch);
> +struct jz4780_bch *of_jz4780_bch_get(struct device_node *np);
> +
> +#endif /* __DRIVERS_MTD_NAND_JZ4780_BCH_H__ */
> diff --git a/drivers/mtd/nand/jz4780_nand.c b/drivers/mtd/nand/jz4780_nand.c
> new file mode 100644
> index 0000000..d8ea35e
> --- /dev/null
> +++ b/drivers/mtd/nand/jz4780_nand.c
> @@ -0,0 +1,422 @@

[...]

> +static int jz4780_nand_init_ecc(struct jz4780_nand_chip *nand, struct device *dev)
> +{
> +	struct nand_chip *chip = &nand->chip;
> +	struct mtd_info *mtd = nand_to_mtd(chip);
> +	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(chip->controller);
> +	struct nand_ecclayout *layout = &nand->ecclayout;
> +	u32 start, i;
> +
> +	chip->ecc.bytes = fls((1 + 8) * chip->ecc.size)	*
> +				(chip->ecc.strength / 8);
> +
> +	if (nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
> +		chip->ecc.hwctl = jz4780_nand_ecc_hwctl;
> +		chip->ecc.calculate = jz4780_nand_ecc_calculate;
> +		chip->ecc.correct = jz4780_nand_ecc_correct;
> +	} else if (!nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
> +		dev_err(dev, "HW BCH selected, but BCH controller not found\n");
> +		return -ENODEV;
> +	}
> +
> +	if (chip->ecc.mode == NAND_ECC_HW_SYNDROME) {
> +		dev_err(dev, "ECC HW syndrome not supported\n");
> +		return -EINVAL;
> +	}
> +
> +	if (chip->ecc.mode != NAND_ECC_NONE)
> +		dev_info(dev, "using %s (strength %d, size %d, bytes %d)\n",
> +			(nfc->bch) ? "hardware BCH" : "software ECC",
> +			chip->ecc.strength, chip->ecc.size, chip->ecc.bytes);
> +	else
> +		dev_info(dev, "not using ECC\n");

Almost seems like all the above would be clearer as a switch/case
statement.

> +
> +	/* The NAND core will generate the ECC layout. */
> +	if (chip->ecc.mode == NAND_ECC_SOFT || chip->ecc.mode == NAND_ECC_SOFT_BCH)
> +		return 0;
> +
> +	/* Generate ECC layout. ECC codes are right aligned in the OOB area. */
> +	layout->eccbytes = mtd->writesize / chip->ecc.size * chip->ecc.bytes;
> +
> +	if (layout->eccbytes > mtd->oobsize - 2) {
> +		dev_err(dev,
> +			"invalid ECC config: required %d ECC bytes, but only %d are available",
> +			layout->eccbytes, mtd->oobsize - 2);
> +		return -EINVAL;
> +	}
> +
> +	start = mtd->oobsize - layout->eccbytes;
> +	for (i = 0; i < layout->eccbytes; i++)
> +		layout->eccpos[i] = start + i;
> +
> +	layout->oobfree[0].offset = 2;
> +	layout->oobfree[0].length = mtd->oobsize - layout->eccbytes - 2;
> +
> +	chip->ecc.layout = layout;
> +	return 0;
> +}
> +
> +static int jz4780_nand_init_chip(struct platform_device *pdev,
> +				struct jz4780_nand_controller *nfc,
> +				struct device_node *np,
> +				unsigned int chipnr)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct jz4780_nand_chip *nand;
> +	struct jz4780_nand_cs *cs;
> +	struct resource *res;
> +	struct nand_chip *chip;
> +	struct mtd_info *mtd;
> +	const __be32 *reg;
> +	int ret = 0;
> +
> +	cs = &nfc->cs[chipnr];
> +
> +	reg = of_get_property(np, "reg", NULL);
> +	if (!reg)
> +		return -EINVAL;
> +
> +	cs->bank = be32_to_cpu(*reg);

Seems like you could use of_property_read_u32(). Not a big deal though.

> +
> +	jz4780_nemc_set_type(nfc->dev, cs->bank, JZ4780_NEMC_BANK_NAND);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, chipnr);
> +	cs->base = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(cs->base))
> +		return PTR_ERR(cs->base);
> +
> +	nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
> +	if (!nand)
> +		return -ENOMEM;
> +
> +	nand->busy_gpio = devm_gpiod_get_optional(dev, "rb", GPIOD_IN);
> +
> +	if (IS_ERR(nand->busy_gpio)) {
> +		ret = PTR_ERR(nand->busy_gpio);
> +		dev_err(dev, "failed to request busy GPIO: %d\n", ret);
> +		return ret;
> +	} else if (nand->busy_gpio) {
> +		nand->chip.dev_ready = jz4780_nand_dev_ready;
> +	}
> +
> +	nand->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_LOW);
> +
> +	if (IS_ERR(nand->wp_gpio)) {
> +		ret = PTR_ERR(nand->wp_gpio);
> +		dev_err(dev, "failed to request WP GPIO: %d\n", ret);
> +		return ret;
> +	}
> +
> +	chip = &nand->chip;
> +	mtd = nand_to_mtd(chip);
> +	mtd->priv = chip;
> +	mtd->owner = THIS_MODULE;

You don't need this line any more.

> +	mtd->name = DRV_NAME;

Looks like you have made some effort to support multiple chips. It'd be
a shame to name them all the same... Maybe use devm_kasprintf() to
construct a unique name for each chip?

> +	mtd->dev.parent = dev;
> +
> +	chip->IO_ADDR_R = cs->base + OFFSET_DATA;
> +	chip->IO_ADDR_W = cs->base + OFFSET_DATA;
> +	chip->chip_delay = RB_DELAY_US;
> +	chip->options = NAND_NO_SUBPAGE_WRITE;
> +	chip->select_chip = jz4780_nand_select_chip;
> +	chip->cmd_ctrl = jz4780_nand_cmd_ctrl;
> +	chip->ecc.mode = NAND_ECC_HW;
> +	chip->controller = &nfc->controller;
> +	nand_set_flash_node(chip, np);
> +
> +	ret = nand_scan_ident(mtd, 1, NULL);
> +	if (ret)
> +		return ret;
> +
> +	ret = jz4780_nand_init_ecc(nand, dev);
> +	if (ret)
> +		return ret;
> +
> +	ret = nand_scan_tail(mtd);
> +	if (ret)
> +		return ret;
> +
> +	ret = mtd_device_register(mtd, NULL, 0);
> +	if (ret) {
> +		nand_release(mtd);
> +		return ret;
> +	}
> +
> +	list_add_tail(&nand->chip_list, &nfc->chips);
> +
> +	return 0;
> +}
> +
> +static void jz4780_nand_cleanup_chips(struct jz4780_nand_controller *nfc)
> +{
> +	struct jz4780_nand_chip *chip;
> +
> +	while (!list_empty(&nfc->chips)) {
> +		chip = list_first_entry(&nfc->chips, struct jz4780_nand_chip, chip_list);
> +		nand_release(nand_to_mtd(&chip->chip));
> +		list_del(&chip->chip_list);
> +	}
> +}
> +
> +static int jz4780_nand_init_chips(struct jz4780_nand_controller *nfc,
> +				  struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np;
> +	int i = 0;
> +	int ret;
> +	int num_chips = of_get_child_count(dev->of_node);
> +
> +	if (num_chips > nfc->num_banks) {
> +		dev_err(dev, "found %d chips but only %d banks\n", num_chips, nfc->num_banks);
> +		return -EINVAL;
> +	}
> +
> +	for_each_child_of_node(dev->of_node, np) {
> +		ret = jz4780_nand_init_chip(pdev, nfc, np, i);
> +		if (ret) {
> +			jz4780_nand_cleanup_chips(nfc);
> +			return ret;
> +		}
> +
> +		i++;
> +	}
> +
> +	return 0;
> +}
> +
> +static int jz4780_nand_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	unsigned int num_banks;
> +	struct jz4780_nand_controller *nfc;
> +	int ret;
> +
> +	num_banks = jz4780_nemc_num_banks(dev);
> +	if (num_banks == 0) {
> +		dev_err(dev, "no banks found\n");
> +		return -ENODEV;
> +	}
> +
> +	nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
> +	if (!nfc)
> +		return -ENOMEM;
> +
> +	/*
> +	 * Check for BCH HW before we call nand_scan_ident, to prevent us from
> +	 * having to call it again if the BCH driver returns -EPROBE_DEFER.
> +	 */
> +	nfc->bch = of_jz4780_bch_get(dev->of_node);
> +	if (IS_ERR(nfc->bch))
> +		return PTR_ERR(nfc->bch);
> +
> +	nfc->dev = dev;
> +	nfc->num_banks = num_banks;
> +
> +	spin_lock_init(&nfc->controller.lock);
> +	INIT_LIST_HEAD(&nfc->chips);
> +	init_waitqueue_head(&nfc->controller.wq);
> +
> +	ret = jz4780_nand_init_chips(nfc, pdev);
> +	if (ret)
> +		if (nfc->bch)
> +			jz4780_bch_release(nfc->bch);
> +		return ret;

coccinelle and smatch notice that you got the bracing wrong here,
causing the rest of this function to be unreachable:

drivers/mtd/nand/jz4780_nand.c:383:2-32: code aligned with following code on line 385 [coccinelle]
drivers/mtd/nand/jz4780_nand.c:385 jz4780_nand_probe() warn: curly braces intended? [smatch]
drivers/mtd/nand/jz4780_nand.c:387 jz4780_nand_probe() info: ignoring unreachable code. [smatch]
drivers/mtd/nand/jz4780_nand.c:387 jz4780_nand_probe() warn: inconsistent indenting [smatch]

You'd only notice that when you remove the device though.

> +
> +	platform_set_drvdata(pdev, nfc);
> +	return 0;
> +}
> +
> +static int jz4780_nand_remove(struct platform_device *pdev)
> +{
> +	struct jz4780_nand_controller *nfc = platform_get_drvdata(pdev);
> +
> +	if (nfc->bch)
> +		jz4780_bch_release(nfc->bch);
> +
> +	jz4780_nand_cleanup_chips(nfc);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id jz4780_nand_dt_match[] = {
> +	{ .compatible = "ingenic,jz4780-nand" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
> +
> +static struct platform_driver jz4780_nand_driver = {
> +	.probe		= jz4780_nand_probe,
> +	.remove		= jz4780_nand_remove,
> +	.driver	= {
> +		.name	= DRV_NAME,
> +		.of_match_table = of_match_ptr(jz4780_nand_dt_match),
> +	},
> +};
> +module_platform_driver(jz4780_nand_driver);
> +
> +MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
> +MODULE_AUTHOR("Harvey Hunt <harvey.hunt@imgtec.com>");
> +MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
> +MODULE_LICENSE("GPL v2");

I'd be OK taking this patch with the following appended diff squashed
in. Thoughts?

Brian

diff --git a/drivers/mtd/nand/jz4780_bch.c b/drivers/mtd/nand/jz4780_bch.c
index 53b2c06af5dc..5954fbfa29e9 100644
--- a/drivers/mtd/nand/jz4780_bch.c
+++ b/drivers/mtd/nand/jz4780_bch.c
@@ -314,6 +314,7 @@ struct jz4780_bch *of_jz4780_bch_get(struct device_node *of_node)
 	}
 	return bch;
 }
+EXPORT_SYMBOL(of_jz4780_bch_get);
 
 /**
  * jz4780_bch_release() - release the BCH controller device
diff --git a/drivers/mtd/nand/jz4780_nand.c b/drivers/mtd/nand/jz4780_nand.c
index d8ea35ed1007..17eb9f264187 100644
--- a/drivers/mtd/nand/jz4780_nand.c
+++ b/drivers/mtd/nand/jz4780_nand.c
@@ -271,8 +271,10 @@ static int jz4780_nand_init_chip(struct platform_device *pdev,
 	chip = &nand->chip;
 	mtd = nand_to_mtd(chip);
 	mtd->priv = chip;
-	mtd->owner = THIS_MODULE;
-	mtd->name = DRV_NAME;
+	mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s.%d", dev_name(dev),
+				   cs->bank);
+	if (!mtd->name)
+		return -ENOMEM;
 	mtd->dev.parent = dev;
 
 	chip->IO_ADDR_R = cs->base + OFFSET_DATA;
@@ -379,10 +381,11 @@ static int jz4780_nand_probe(struct platform_device *pdev)
 	init_waitqueue_head(&nfc->controller.wq);
 
 	ret = jz4780_nand_init_chips(nfc, pdev);
-	if (ret)
+	if (ret) {
 		if (nfc->bch)
 			jz4780_bch_release(nfc->bch);
 		return ret;
+	}
 
 	platform_set_drvdata(pdev, nfc);
 	return 0;

Re: [PATCH v11 1/3] dt-bindings: binding for jz4780-{nand,bch}

[Brian Norris]

On Mon, Jan 04, 2016 at 12:34:42PM +0000, Harvey Hunt wrote:
> From: Alex Smith <alex.smith@imgtec.com>
> 
> Add DT bindings for NAND devices connected to the NEMC on JZ4780 SoCs,
> as well as the hardware BCH controller, used by the jz4780_{nand,bch}
> drivers.
> 
> Signed-off-by: Alex Smith <alex.smith@imgtec.com>
> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
> Cc: David Woodhouse <dwmw2@infradead.org>
> Cc: Brian Norris <computersforpeace@gmail.com>
> Cc: linux-mtd@lists.infradead.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: robh@kernel.org
> Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
> Acked-by: Rob Herring <robh@kernel.org>
> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> ---
> v10 -> v11:
>  - Added Boris Brezillon's Reviewed-By.

Applied just patch 1 for now. I had some small comments on patch 2. And
you need to send patch 3 to linux-mips and the MIPS maintainer.

Brian

Re: [PATCH v11 3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes

[Brian Norris]

On Mon, Jan 04, 2016 at 12:34:44PM +0000, Harvey Hunt wrote:
> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
> index 9fcb9e7..782258c 100644
> --- a/arch/mips/boot/dts/ingenic/ci20.dts
> +++ b/arch/mips/boot/dts/ingenic/ci20.dts

As I noted on patch 1, you need to send this to linux-mips + Ralf.

> @@ -42,3 +42,66 @@
>  &uart4 {
>  	status = "okay";
>  };
> +
> +&nemc {
> +	status = "okay";
> +
> +	nandc: nand-controller@1 {
> +		compatible = "ingenic,jz4780-nand";
> +		reg = <1 0 0x1000000>;
> +
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		ingenic,bch-controller = <&bch>;
> +
> +		ingenic,nemc-tAS = <10>;
> +		ingenic,nemc-tAH = <5>;
> +		ingenic,nemc-tBP = <10>;
> +		ingenic,nemc-tAW = <15>;
> +		ingenic,nemc-tSTRV = <100>;
> +
> +		nand@1 {
> +			reg = <1>;
> +
> +			nand-ecc-step-size = <1024>;
> +			nand-ecc-strength = <24>;
> +			nand-ecc-mode = "hw";
> +			nand-on-flash-bbt;
> +
> +			partitions {
> +				#address-cells = <2>;
> +				#size-cells = <2>;

This binding was updated, so you need:

				compatible = "fixed-partitions";

Brian

> +
> +				partition@0 {
> +					label = "u-boot-spl";
> +					reg = <0x0 0x0 0x0 0x800000>;
> +				};
> +
> +				partition@0x800000 {
> +					label = "u-boot";
> +					reg = <0x0 0x800000 0x0 0x200000>;
> +				};
> +
> +				partition@0xa00000 {
> +					label = "u-boot-env";
> +					reg = <0x0 0xa00000 0x0 0x200000>;
> +				};
> +
> +				partition@0xc00000 {
> +					label = "boot";
> +					reg = <0x0 0xc00000 0x0 0x4000000>;
> +				};
> +
> +				partition@0x8c00000 {
> +					label = "system";
> +					reg = <0x0 0x4c00000 0x1 0xfb400000>;
> +				};
> +			};
> +		};
> +	};
> +};
> +
> +&bch {
> +	status = "okay";
> +};

Brian

Re: [PATCH v11 3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes

[Harvey Hunt]

Hi Brian,

On 07/01/16 01:29, Brian Norris wrote:
> On Mon, Jan 04, 2016 at 12:34:44PM +0000, Harvey Hunt wrote:
>> diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
>> index 9fcb9e7..782258c 100644
>> --- a/arch/mips/boot/dts/ingenic/ci20.dts
>> +++ b/arch/mips/boot/dts/ingenic/ci20.dts
>
> As I noted on patch 1, you need to send this to linux-mips + Ralf.

I forgot to CC Ralf on this version, but he took v9 (no change between 
v9 and v11) through linux-mips as can be seen here: 
http://patchwork.linux-mips.org/patch/11695/

>
>> @@ -42,3 +42,66 @@
>>   &uart4 {
>>   	status = "okay";
>>   };
>> +
>> +&nemc {
>> +	status = "okay";
>> +
>> +	nandc: nand-controller@1 {
>> +		compatible = "ingenic,jz4780-nand";
>> +		reg = <1 0 0x1000000>;
>> +
>> +		#address-cells = <1>;
>> +		#size-cells = <0>;
>> +
>> +		ingenic,bch-controller = <&bch>;
>> +
>> +		ingenic,nemc-tAS = <10>;
>> +		ingenic,nemc-tAH = <5>;
>> +		ingenic,nemc-tBP = <10>;
>> +		ingenic,nemc-tAW = <15>;
>> +		ingenic,nemc-tSTRV = <100>;
>> +
>> +		nand@1 {
>> +			reg = <1>;
>> +
>> +			nand-ecc-step-size = <1024>;
>> +			nand-ecc-strength = <24>;
>> +			nand-ecc-mode = "hw";
>> +			nand-on-flash-bbt;
>> +
>> +			partitions {
>> +				#address-cells = <2>;
>> +				#size-cells = <2>;
>
> This binding was updated, so you need:
>
> 				compatible = "fixed-partitions";

This has been fixed in mips-linux here: 
http://patchwork.linux-mips.org/patch/11914/

Thanks,

Harvey

>
> Brian
>
>> +
>> +				partition@0 {
>> +					label = "u-boot-spl";
>> +					reg = <0x0 0x0 0x0 0x800000>;
>> +				};
>> +
>> +				partition@0x800000 {
>> +					label = "u-boot";
>> +					reg = <0x0 0x800000 0x0 0x200000>;
>> +				};
>> +
>> +				partition@0xa00000 {
>> +					label = "u-boot-env";
>> +					reg = <0x0 0xa00000 0x0 0x200000>;
>> +				};
>> +
>> +				partition@0xc00000 {
>> +					label = "boot";
>> +					reg = <0x0 0xc00000 0x0 0x4000000>;
>> +				};
>> +
>> +				partition@0x8c00000 {
>> +					label = "system";
>> +					reg = <0x0 0x4c00000 0x1 0xfb400000>;
>> +				};
>> +			};
>> +		};
>> +	};
>> +};
>> +
>> +&bch {
>> +	status = "okay";
>> +};
>
> Brian
>

Re: [PATCH v11 2/3] mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs

[Harvey Hunt]

Hi Brian,

On 07/01/16 01:15, Brian Norris wrote:
> Hi Harvey,
>
> On Mon, Jan 04, 2016 at 12:34:43PM +0000, Harvey Hunt wrote:
>> From: Alex Smith <alex.smith@imgtec.com>
>>
>> Add a driver for NAND devices connected to the NEMC on JZ4780 SoCs, as
>> well as the hardware BCH controller. DMA is not currently implemented.
>>
>> While older 47xx SoCs also have a BCH controller, they are incompatible
>> with the one in the 4780 due to differing register/bit positions, which
>> would make implementing a common driver for them quite messy.
>>
>> Signed-off-by: Alex Smith <alex.smith@imgtec.com>
>> Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
>> Cc: David Woodhouse <dwmw2@infradead.org>
>> Cc: Brian Norris <computersforpeace@gmail.com>
>> Cc: linux-mtd@lists.infradead.org
>> Cc: linux-kernel@vger.kernel.org
>> Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
>> Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
>> ---
> [...]
>
>>   drivers/mtd/nand/Kconfig       |   7 +
>>   drivers/mtd/nand/Makefile      |   1 +
>>   drivers/mtd/nand/jz4780_bch.c  | 380 +++++++++++++++++++++++++++++++++++++
>>   drivers/mtd/nand/jz4780_bch.h  |  43 +++++
>>   drivers/mtd/nand/jz4780_nand.c | 422 +++++++++++++++++++++++++++++++++++++++++
>>   5 files changed, 853 insertions(+)
>>   create mode 100644 drivers/mtd/nand/jz4780_bch.c
>>   create mode 100644 drivers/mtd/nand/jz4780_bch.h
>>   create mode 100644 drivers/mtd/nand/jz4780_nand.c
>>
>> diff --git a/drivers/mtd/nand/Kconfig b/drivers/mtd/nand/Kconfig
>> index 2896640..b742adc 100644
>> --- a/drivers/mtd/nand/Kconfig
>> +++ b/drivers/mtd/nand/Kconfig
>> @@ -519,6 +519,13 @@ config MTD_NAND_JZ4740
>>   	help
>>   		Enables support for NAND Flash on JZ4740 SoC based boards.
>>
>> +config MTD_NAND_JZ4780
>> +	tristate "Support for NAND on JZ4780 SoC"
>> +	depends on MACH_JZ4780 && JZ4780_NEMC
>> +	help
>> +	  Enables support for NAND Flash connected to the NEMC on JZ4780 SoC
>> +	  based boards, using the BCH controller for hardware error correction.
>> +
>>   config MTD_NAND_FSMC
>>   	tristate "Support for NAND on ST Micros FSMC"
>>   	depends on PLAT_SPEAR || ARCH_NOMADIK || ARCH_U8500 || MACH_U300
>> diff --git a/drivers/mtd/nand/Makefile b/drivers/mtd/nand/Makefile
>> index 2c7f014..9e36233 100644
>> --- a/drivers/mtd/nand/Makefile
>> +++ b/drivers/mtd/nand/Makefile
>> @@ -49,6 +49,7 @@ obj-$(CONFIG_MTD_NAND_MPC5121_NFC)	+= mpc5121_nfc.o
>>   obj-$(CONFIG_MTD_NAND_VF610_NFC)	+= vf610_nfc.o
>>   obj-$(CONFIG_MTD_NAND_RICOH)		+= r852.o
>>   obj-$(CONFIG_MTD_NAND_JZ4740)		+= jz4740_nand.o
>> +obj-$(CONFIG_MTD_NAND_JZ4780)		+= jz4780_nand.o jz4780_bch.o
>>   obj-$(CONFIG_MTD_NAND_GPMI_NAND)	+= gpmi-nand/
>>   obj-$(CONFIG_MTD_NAND_XWAY)		+= xway_nand.o
>>   obj-$(CONFIG_MTD_NAND_BCM47XXNFLASH)	+= bcm47xxnflash/
>> diff --git a/drivers/mtd/nand/jz4780_bch.c b/drivers/mtd/nand/jz4780_bch.c
>> new file mode 100644
>> index 0000000..53b2c06
>> --- /dev/null
>> +++ b/drivers/mtd/nand/jz4780_bch.c
>> @@ -0,0 +1,380 @@
>
> [...]
>
>> +/**
>> + * of_jz4780_bch_get() - get the BCH controller from a DT node
>> + * @of_node: the node that contains a bch-controller property.
>> + *
>> + * Get the bch-controller property from the given device tree
>> + * node and pass it to jz4780_bch_get to do the work.
>> + *
>> + * Return: a pointer to jz4780_bch, errors are encoded into the pointer.
>> + * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
>> + */
>> +struct jz4780_bch *of_jz4780_bch_get(struct device_node *of_node)
>> +{
>> +	struct jz4780_bch *bch = NULL;
>> +	struct device_node *np;
>> +
>> +	np = of_parse_phandle(of_node, "ingenic,bch-controller", 0);
>> +
>> +	if (np) {
>> +		bch = jz4780_bch_get(np);
>> +		of_node_put(np);
>> +	}
>> +	return bch;
>> +}
>
> Don't you need to EXPORT_SYMBOL() this one?
>
> [...]

Correct, I missed that.

>
>> diff --git a/drivers/mtd/nand/jz4780_bch.h b/drivers/mtd/nand/jz4780_bch.h
>> new file mode 100644
>> index 0000000..bf471808
>> --- /dev/null
>> +++ b/drivers/mtd/nand/jz4780_bch.h
>> @@ -0,0 +1,43 @@
>> +/*
>> + * JZ4780 BCH controller
>> + *
>> + * Copyright (c) 2015 Imagination Technologies
>> + * Author: Alex Smith <alex.smith@imgtec.com>
>> + *
>> + * This program is free software; you can redistribute it and/or modify it
>> + * under the terms of the GNU General Public License version 2 as published
>> + * by the Free Software Foundation.
>> + */
>> +
>> +#ifndef __DRIVERS_MTD_NAND_JZ4780_BCH_H__
>> +#define __DRIVERS_MTD_NAND_JZ4780_BCH_H__
>> +
>> +#include <linux/types.h>
>> +
>> +struct device;
>> +struct device_node;
>> +struct jz4780_bch;
>> +
>> +/**
>> + * struct jz4780_bch_params - BCH parameters
>> + * @size: data bytes per ECC step.
>> + * @bytes: ECC bytes per step.
>> + * @strength: number of correctable bits per ECC step.
>> + */
>> +struct jz4780_bch_params {
>> +	int size;
>> +	int bytes;
>> +	int strength;
>> +};
>> +
>> +int jz4780_bch_calculate(struct jz4780_bch *bch,
>> +				struct jz4780_bch_params *params,
>> +				const u8 *buf, u8 *ecc_code);
>> +int jz4780_bch_correct(struct jz4780_bch *bch,
>> +			      struct jz4780_bch_params *params, u8 *buf,
>> +			      u8 *ecc_code);
>> +
>> +void jz4780_bch_release(struct jz4780_bch *bch);
>> +struct jz4780_bch *of_jz4780_bch_get(struct device_node *np);
>> +
>> +#endif /* __DRIVERS_MTD_NAND_JZ4780_BCH_H__ */
>> diff --git a/drivers/mtd/nand/jz4780_nand.c b/drivers/mtd/nand/jz4780_nand.c
>> new file mode 100644
>> index 0000000..d8ea35e
>> --- /dev/null
>> +++ b/drivers/mtd/nand/jz4780_nand.c
>> @@ -0,0 +1,422 @@
>
> [...]
>
>> +static int jz4780_nand_init_ecc(struct jz4780_nand_chip *nand, struct device *dev)
>> +{
>> +	struct nand_chip *chip = &nand->chip;
>> +	struct mtd_info *mtd = nand_to_mtd(chip);
>> +	struct jz4780_nand_controller *nfc = to_jz4780_nand_controller(chip->controller);
>> +	struct nand_ecclayout *layout = &nand->ecclayout;
>> +	u32 start, i;
>> +
>> +	chip->ecc.bytes = fls((1 + 8) * chip->ecc.size)	*
>> +				(chip->ecc.strength / 8);
>> +
>> +	if (nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
>> +		chip->ecc.hwctl = jz4780_nand_ecc_hwctl;
>> +		chip->ecc.calculate = jz4780_nand_ecc_calculate;
>> +		chip->ecc.correct = jz4780_nand_ecc_correct;
>> +	} else if (!nfc->bch && chip->ecc.mode == NAND_ECC_HW) {
>> +		dev_err(dev, "HW BCH selected, but BCH controller not found\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	if (chip->ecc.mode == NAND_ECC_HW_SYNDROME) {
>> +		dev_err(dev, "ECC HW syndrome not supported\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (chip->ecc.mode != NAND_ECC_NONE)
>> +		dev_info(dev, "using %s (strength %d, size %d, bytes %d)\n",
>> +			(nfc->bch) ? "hardware BCH" : "software ECC",
>> +			chip->ecc.strength, chip->ecc.size, chip->ecc.bytes);
>> +	else
>> +		dev_info(dev, "not using ECC\n");
>
> Almost seems like all the above would be clearer as a switch/case
> statement.

I agree.

>
>> +
>> +	/* The NAND core will generate the ECC layout. */
>> +	if (chip->ecc.mode == NAND_ECC_SOFT || chip->ecc.mode == NAND_ECC_SOFT_BCH)
>> +		return 0;
>> +
>> +	/* Generate ECC layout. ECC codes are right aligned in the OOB area. */
>> +	layout->eccbytes = mtd->writesize / chip->ecc.size * chip->ecc.bytes;
>> +
>> +	if (layout->eccbytes > mtd->oobsize - 2) {
>> +		dev_err(dev,
>> +			"invalid ECC config: required %d ECC bytes, but only %d are available",
>> +			layout->eccbytes, mtd->oobsize - 2);
>> +		return -EINVAL;
>> +	}
>> +
>> +	start = mtd->oobsize - layout->eccbytes;
>> +	for (i = 0; i < layout->eccbytes; i++)
>> +		layout->eccpos[i] = start + i;
>> +
>> +	layout->oobfree[0].offset = 2;
>> +	layout->oobfree[0].length = mtd->oobsize - layout->eccbytes - 2;
>> +
>> +	chip->ecc.layout = layout;
>> +	return 0;
>> +}
>> +
>> +static int jz4780_nand_init_chip(struct platform_device *pdev,
>> +				struct jz4780_nand_controller *nfc,
>> +				struct device_node *np,
>> +				unsigned int chipnr)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct jz4780_nand_chip *nand;
>> +	struct jz4780_nand_cs *cs;
>> +	struct resource *res;
>> +	struct nand_chip *chip;
>> +	struct mtd_info *mtd;
>> +	const __be32 *reg;
>> +	int ret = 0;
>> +
>> +	cs = &nfc->cs[chipnr];
>> +
>> +	reg = of_get_property(np, "reg", NULL);
>> +	if (!reg)
>> +		return -EINVAL;
>> +
>> +	cs->bank = be32_to_cpu(*reg);
>
> Seems like you could use of_property_read_u32(). Not a big deal though.

Ack.

>> +
>> +	jz4780_nemc_set_type(nfc->dev, cs->bank, JZ4780_NEMC_BANK_NAND);
>> +
>> +	res = platform_get_resource(pdev, IORESOURCE_MEM, chipnr);
>> +	cs->base = devm_ioremap_resource(dev, res);
>> +	if (IS_ERR(cs->base))
>> +		return PTR_ERR(cs->base);
>> +
>> +	nand = devm_kzalloc(dev, sizeof(*nand), GFP_KERNEL);
>> +	if (!nand)
>> +		return -ENOMEM;
>> +
>> +	nand->busy_gpio = devm_gpiod_get_optional(dev, "rb", GPIOD_IN);
>> +
>> +	if (IS_ERR(nand->busy_gpio)) {
>> +		ret = PTR_ERR(nand->busy_gpio);
>> +		dev_err(dev, "failed to request busy GPIO: %d\n", ret);
>> +		return ret;
>> +	} else if (nand->busy_gpio) {
>> +		nand->chip.dev_ready = jz4780_nand_dev_ready;
>> +	}
>> +
>> +	nand->wp_gpio = devm_gpiod_get_optional(dev, "wp", GPIOD_OUT_LOW);
>> +
>> +	if (IS_ERR(nand->wp_gpio)) {
>> +		ret = PTR_ERR(nand->wp_gpio);
>> +		dev_err(dev, "failed to request WP GPIO: %d\n", ret);
>> +		return ret;
>> +	}
>> +
>> +	chip = &nand->chip;
>> +	mtd = nand_to_mtd(chip);
>> +	mtd->priv = chip;
>> +	mtd->owner = THIS_MODULE;
>
> You don't need this line any more.

Okay.

>
>> +	mtd->name = DRV_NAME;
>
> Looks like you have made some effort to support multiple chips. It'd be
> a shame to name them all the same... Maybe use devm_kasprintf() to
> construct a unique name for each chip?

You're right.

>
>> +	mtd->dev.parent = dev;
>> +
>> +	chip->IO_ADDR_R = cs->base + OFFSET_DATA;
>> +	chip->IO_ADDR_W = cs->base + OFFSET_DATA;
>> +	chip->chip_delay = RB_DELAY_US;
>> +	chip->options = NAND_NO_SUBPAGE_WRITE;
>> +	chip->select_chip = jz4780_nand_select_chip;
>> +	chip->cmd_ctrl = jz4780_nand_cmd_ctrl;
>> +	chip->ecc.mode = NAND_ECC_HW;
>> +	chip->controller = &nfc->controller;
>> +	nand_set_flash_node(chip, np);
>> +
>> +	ret = nand_scan_ident(mtd, 1, NULL);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = jz4780_nand_init_ecc(nand, dev);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = nand_scan_tail(mtd);
>> +	if (ret)
>> +		return ret;
>> +
>> +	ret = mtd_device_register(mtd, NULL, 0);
>> +	if (ret) {
>> +		nand_release(mtd);
>> +		return ret;
>> +	}
>> +
>> +	list_add_tail(&nand->chip_list, &nfc->chips);
>> +
>> +	return 0;
>> +}
>> +
>> +static void jz4780_nand_cleanup_chips(struct jz4780_nand_controller *nfc)
>> +{
>> +	struct jz4780_nand_chip *chip;
>> +
>> +	while (!list_empty(&nfc->chips)) {
>> +		chip = list_first_entry(&nfc->chips, struct jz4780_nand_chip, chip_list);
>> +		nand_release(nand_to_mtd(&chip->chip));
>> +		list_del(&chip->chip_list);
>> +	}
>> +}
>> +
>> +static int jz4780_nand_init_chips(struct jz4780_nand_controller *nfc,
>> +				  struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *np;
>> +	int i = 0;
>> +	int ret;
>> +	int num_chips = of_get_child_count(dev->of_node);
>> +
>> +	if (num_chips > nfc->num_banks) {
>> +		dev_err(dev, "found %d chips but only %d banks\n", num_chips, nfc->num_banks);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for_each_child_of_node(dev->of_node, np) {
>> +		ret = jz4780_nand_init_chip(pdev, nfc, np, i);
>> +		if (ret) {
>> +			jz4780_nand_cleanup_chips(nfc);
>> +			return ret;
>> +		}
>> +
>> +		i++;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int jz4780_nand_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	unsigned int num_banks;
>> +	struct jz4780_nand_controller *nfc;
>> +	int ret;
>> +
>> +	num_banks = jz4780_nemc_num_banks(dev);
>> +	if (num_banks == 0) {
>> +		dev_err(dev, "no banks found\n");
>> +		return -ENODEV;
>> +	}
>> +
>> +	nfc = devm_kzalloc(dev, sizeof(*nfc) + (sizeof(nfc->cs[0]) * num_banks), GFP_KERNEL);
>> +	if (!nfc)
>> +		return -ENOMEM;
>> +
>> +	/*
>> +	 * Check for BCH HW before we call nand_scan_ident, to prevent us from
>> +	 * having to call it again if the BCH driver returns -EPROBE_DEFER.
>> +	 */
>> +	nfc->bch = of_jz4780_bch_get(dev->of_node);
>> +	if (IS_ERR(nfc->bch))
>> +		return PTR_ERR(nfc->bch);
>> +
>> +	nfc->dev = dev;
>> +	nfc->num_banks = num_banks;
>> +
>> +	spin_lock_init(&nfc->controller.lock);
>> +	INIT_LIST_HEAD(&nfc->chips);
>> +	init_waitqueue_head(&nfc->controller.wq);
>> +
>> +	ret = jz4780_nand_init_chips(nfc, pdev);
>> +	if (ret)
>> +		if (nfc->bch)
>> +			jz4780_bch_release(nfc->bch);
>> +		return ret;
>
> coccinelle and smatch notice that you got the bracing wrong here,
> causing the rest of this function to be unreachable:
>
> drivers/mtd/nand/jz4780_nand.c:383:2-32: code aligned with following code on line 385 [coccinelle]
> drivers/mtd/nand/jz4780_nand.c:385 jz4780_nand_probe() warn: curly braces intended? [smatch]
> drivers/mtd/nand/jz4780_nand.c:387 jz4780_nand_probe() info: ignoring unreachable code. [smatch]
> drivers/mtd/nand/jz4780_nand.c:387 jz4780_nand_probe() warn: inconsistent indenting [smatch]
>
> You'd only notice that when you remove the device though.

I forgot to run coccinelle on this version of the patchset - I was still 
in Christmas holiday mode ;-)

>
>> +
>> +	platform_set_drvdata(pdev, nfc);
>> +	return 0;
>> +}
>> +
>> +static int jz4780_nand_remove(struct platform_device *pdev)
>> +{
>> +	struct jz4780_nand_controller *nfc = platform_get_drvdata(pdev);
>> +
>> +	if (nfc->bch)
>> +		jz4780_bch_release(nfc->bch);
>> +
>> +	jz4780_nand_cleanup_chips(nfc);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id jz4780_nand_dt_match[] = {
>> +	{ .compatible = "ingenic,jz4780-nand" },
>> +	{},
>> +};
>> +MODULE_DEVICE_TABLE(of, jz4780_nand_dt_match);
>> +
>> +static struct platform_driver jz4780_nand_driver = {
>> +	.probe		= jz4780_nand_probe,
>> +	.remove		= jz4780_nand_remove,
>> +	.driver	= {
>> +		.name	= DRV_NAME,
>> +		.of_match_table = of_match_ptr(jz4780_nand_dt_match),
>> +	},
>> +};
>> +module_platform_driver(jz4780_nand_driver);
>> +
>> +MODULE_AUTHOR("Alex Smith <alex@alex-smith.me.uk>");
>> +MODULE_AUTHOR("Harvey Hunt <harvey.hunt@imgtec.com>");
>> +MODULE_DESCRIPTION("Ingenic JZ4780 NAND driver");
>> +MODULE_LICENSE("GPL v2");
>
> I'd be OK taking this patch with the following appended diff squashed
> in. Thoughts?

It'd be great if you could do that.

Thanks,

Harvey

>
> Brian
>
> diff --git a/drivers/mtd/nand/jz4780_bch.c b/drivers/mtd/nand/jz4780_bch.c
> index 53b2c06af5dc..5954fbfa29e9 100644
> --- a/drivers/mtd/nand/jz4780_bch.c
> +++ b/drivers/mtd/nand/jz4780_bch.c
> @@ -314,6 +314,7 @@ struct jz4780_bch *of_jz4780_bch_get(struct device_node *of_node)
>   	}
>   	return bch;
>   }
> +EXPORT_SYMBOL(of_jz4780_bch_get);
>
>   /**
>    * jz4780_bch_release() - release the BCH controller device
> diff --git a/drivers/mtd/nand/jz4780_nand.c b/drivers/mtd/nand/jz4780_nand.c
> index d8ea35ed1007..17eb9f264187 100644
> --- a/drivers/mtd/nand/jz4780_nand.c
> +++ b/drivers/mtd/nand/jz4780_nand.c
> @@ -271,8 +271,10 @@ static int jz4780_nand_init_chip(struct platform_device *pdev,
>   	chip = &nand->chip;
>   	mtd = nand_to_mtd(chip);
>   	mtd->priv = chip;
> -	mtd->owner = THIS_MODULE;
> -	mtd->name = DRV_NAME;
> +	mtd->name = devm_kasprintf(dev, GFP_KERNEL, "%s.%d", dev_name(dev),
> +				   cs->bank);
> +	if (!mtd->name)
> +		return -ENOMEM;
>   	mtd->dev.parent = dev;
>
>   	chip->IO_ADDR_R = cs->base + OFFSET_DATA;
> @@ -379,10 +381,11 @@ static int jz4780_nand_probe(struct platform_device *pdev)
>   	init_waitqueue_head(&nfc->controller.wq);
>
>   	ret = jz4780_nand_init_chips(nfc, pdev);
> -	if (ret)
> +	if (ret) {
>   		if (nfc->bch)
>   			jz4780_bch_release(nfc->bch);
>   		return ret;
> +	}
>
>   	platform_set_drvdata(pdev, nfc);
>   	return 0;
>

Re: [PATCH v11 3/3] MIPS: dts: jz4780/ci20: Add NEMC, BCH and NAND device tree nodes

[Brian Norris]

Hi Harvey + Ralf,

On Thu, Jan 07, 2016 at 09:40:13AM +0000, Harvey Hunt wrote:
> On 07/01/16 01:29, Brian Norris wrote:
> >On Mon, Jan 04, 2016 at 12:34:44PM +0000, Harvey Hunt wrote:
> >>diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts
> >>index 9fcb9e7..782258c 100644
> >>--- a/arch/mips/boot/dts/ingenic/ci20.dts
> >>+++ b/arch/mips/boot/dts/ingenic/ci20.dts
> >
> >As I noted on patch 1, you need to send this to linux-mips + Ralf.
> 
> I forgot to CC Ralf on this version, but he took v9 (no change
> between v9 and v11) through linux-mips as can be seen here:
> http://patchwork.linux-mips.org/patch/11695/

OK.

> >>@@ -42,3 +42,66 @@
> >>  &uart4 {
> >>  	status = "okay";
> >>  };
> >>+
> >>+&nemc {
> >>+	status = "okay";
> >>+
> >>+	nandc: nand-controller@1 {
> >>+		compatible = "ingenic,jz4780-nand";
> >>+		reg = <1 0 0x1000000>;
> >>+
> >>+		#address-cells = <1>;
> >>+		#size-cells = <0>;
> >>+
> >>+		ingenic,bch-controller = <&bch>;
> >>+
> >>+		ingenic,nemc-tAS = <10>;
> >>+		ingenic,nemc-tAH = <5>;
> >>+		ingenic,nemc-tBP = <10>;
> >>+		ingenic,nemc-tAW = <15>;
> >>+		ingenic,nemc-tSTRV = <100>;
> >>+
> >>+		nand@1 {
> >>+			reg = <1>;
> >>+
> >>+			nand-ecc-step-size = <1024>;
> >>+			nand-ecc-strength = <24>;
> >>+			nand-ecc-mode = "hw";
> >>+			nand-on-flash-bbt;
> >>+
> >>+			partitions {
> >>+				#address-cells = <2>;
> >>+				#size-cells = <2>;
> >
> >This binding was updated, so you need:
> >
> >				compatible = "fixed-partitions";
> 
> This has been fixed in mips-linux here:
> http://patchwork.linux-mips.org/patch/11914/

Ralf: it looks like you applied the DTS changes twice, essentially.
Might want to fix that:

[From arch/mips/boot/dts/ingenic/ci20.dts]
...
&nemc {
	...
	nandc: nand-controller@1 {
		...
		nand@1 {
			...
			partitions {
				compatible = "fixed-partitions";
				...
			};
		};
	};
};

&bch {
	status = "okay";
};

&nemc {
	...
	nandc: nand-controller@1 {
		...
		nand@1 {
			...
			partitions {
				...
			};
		};
	};
};

&bch {
	status = "okay";
};


Brian

Re: [PATCH v11 2/3] mtd: nand: jz4780: driver for NAND devices on JZ4780 SoCs

[Brian Norris]

On Thu, Jan 07, 2016 at 09:44:46AM +0000, Harvey Hunt wrote:
> On 07/01/16 01:15, Brian Norris wrote:
> >On Mon, Jan 04, 2016 at 12:34:43PM +0000, Harvey Hunt wrote:
> >>From: Alex Smith <alex.smith@imgtec.com>
> >>
> >>Add a driver for NAND devices connected to the NEMC on JZ4780 SoCs, as
> >>well as the hardware BCH controller. DMA is not currently implemented.
> >>
> >>While older 47xx SoCs also have a BCH controller, they are incompatible
> >>with the one in the 4780 due to differing register/bit positions, which
> >>would make implementing a common driver for them quite messy.
> >>
> >>Signed-off-by: Alex Smith <alex.smith@imgtec.com>
> >>Cc: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
> >>Cc: David Woodhouse <dwmw2@infradead.org>
> >>Cc: Brian Norris <computersforpeace@gmail.com>
> >>Cc: linux-mtd@lists.infradead.org
> >>Cc: linux-kernel@vger.kernel.org
> >>Signed-off-by: Harvey Hunt <harvey.hunt@imgtec.com>
> >>Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
> >>---

[...]

> >I'd be OK taking this patch with the following appended diff squashed
> >in. Thoughts?
> 
> It'd be great if you could do that.

OK, squashed and applied to l2-mtd.git

Thanks,
Brian