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Subject: [v3,2/5] mtd: nand: Qualcomm NAND controller driver
From: Archit Taneja <architt@codeaurora.org>
X-Patchwork-Id: 6927101
Message-Id: <1438578498-32254-3-git-send-email-architt@codeaurora.org>
To: linux-mtd@lists.infradead.org, dehrenberg@google.com,
cernekee@gmail.com, computersforpeace@gmail.com
Cc: linux-arm-msm@vger.kernel.org, agross@codeaurora.org,
sboyd@codeaurora.org, linux-kernel@vger.kernel.org,
Archit Taneja <architt@codeaurora.org>
Date: Mon, 3 Aug 2015 10:38:15 +0530
The Qualcomm NAND controller is found in SoCs like IPQ806x, MSM7xx,
MDM9x15 series.
It exists as a sub block inside the IPs EBI2 (External Bus Interface 2)
and QPIC (Qualcomm Parallel Interface Controller). These IPs provide a
broader interface for external slow peripheral devices such as LCD and
NAND/NOR flash memory or SRAM like interfaces.
We add support for the NAND controller found within EBI2. For the SoCs
of our interest, we only use the NAND controller within EBI2. Therefore,
it's safe for us to assume that the NAND controller is a standalone block
within the SoC.
The controller supports 512B, 2kB, 4kB and 8kB page 8-bit and 16-bit NAND
flash devices. It contains a HW ECC block that supports BCH ECC (4, 8 and
16 bit correction/step) and RS ECC(4 bit correction/step) that covers main
and spare data. The controller contains an internal 512 byte page buffer
to which we read/write via DMA. The EBI2 type NAND controller uses ADM DMA
for register read/write and data transfers. The controller performs page
reads and writes at a codeword/step level of 512 bytes. It can support up
to 2 external chips of different configurations.
The driver prepares register read and write configuration descriptors for
each codeword, followed by data descriptors to read or write data from the
controller's internal buffer. It uses a single ADM DMA channel that we get
via dmaengine API. The controller requires 2 ADM CRCIs for command and
data flow control. These are passed via DT.
The ecc layout used by the controller is syndrome like, but we can't use
the standard syndrome ecc ops because of several reasons. First, the amount
of data bytes covered by ecc isn't same in each step. Second, writing to
free oob space requires us writing to the entire step in which the oob
lies. This forces us to create our own ecc ops.
One more difference is how the controller accesses the bad block marker.
The controller ignores reading the marker when ECC is enabled. ECC needs
to be explicity disabled to read or write to the bad block marker. For
this reason, we use the newly created flag NAND_BBT_ACCESS_BBM_RAW to
read the factory provided bad block markers.
v3:
- Refactor dma functions for maximum reuse
- Use dma_slave_confing on stack
- optimize and clean upempty_page_fixup using memchr_inv
- ensure portability with dma register reads using le32_* funcs
- use NAND_USE_BOUNCE_BUFFER instead of doing it ourselves
- fix handling of return values of dmaengine funcs
- constify wherever possible
- Remove dependency on ADM DMA in Kconfig
- Misc fixes and clean ups
v2:
- Use new BBT flag that allows us to read BBM in raw mode
- reduce memcpy-s in the driver
- some refactor and clean ups because of above changes
Reviewed-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
---
drivers/mtd/nand/Kconfig | 7 +
drivers/mtd/nand/Makefile | 1 +
drivers/mtd/nand/qcom_nandc.c | 1913 +++++++++++++++++++++++++++++++++++++++++
3 files changed, 1921 insertions(+)
create mode 100644 drivers/mtd/nand/qcom_nandc.c
--- a/drivers/mtd/nand/Kconfig
+++ b/drivers/mtd/nand/Kconfig
@@ -530,4 +530,11 @@ config MTD_NAND_HISI504
help
Enables support for NAND controller on Hisilicon SoC Hip04.
+config MTD_NAND_QCOM
+ tristate "Support for NAND on QCOM SoCs"
+ depends on ARCH_QCOM
+ help
+ Enables support for NAND flash chips on SoCs containing the EBI2 NAND
+ controller. This controller is found on IPQ806x SoC.
+
endif # MTD_NAND
--- /dev/null
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -0,0 +1,1918 @@
+/*
+ * Copyright (c) 2015, The Linux Foundation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/module.h>
+#include <linux/mtd/nand.h>
+#include <linux/mtd/partitions.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_mtd.h>
+#include <linux/delay.h>
+
+/* NANDc reg offsets */
+#define NAND_FLASH_CMD 0x00
+#define NAND_ADDR0 0x04
+#define NAND_ADDR1 0x08
+#define NAND_FLASH_CHIP_SELECT 0x0c
+#define NAND_EXEC_CMD 0x10
+#define NAND_FLASH_STATUS 0x14
+#define NAND_BUFFER_STATUS 0x18
+#define NAND_DEV0_CFG0 0x20
+#define NAND_DEV0_CFG1 0x24
+#define NAND_DEV0_ECC_CFG 0x28
+#define NAND_DEV1_ECC_CFG 0x2c
+#define NAND_DEV1_CFG0 0x30
+#define NAND_DEV1_CFG1 0x34
+#define NAND_READ_ID 0x40
+#define NAND_READ_STATUS 0x44
+#define NAND_DEV_CMD0 0xa0
+#define NAND_DEV_CMD1 0xa4
+#define NAND_DEV_CMD2 0xa8
+#define NAND_DEV_CMD_VLD 0xac
+#define SFLASHC_BURST_CFG 0xe0
+#define NAND_ERASED_CW_DETECT_CFG 0xe8
+#define NAND_ERASED_CW_DETECT_STATUS 0xec
+#define NAND_EBI2_ECC_BUF_CFG 0xf0
+#define FLASH_BUF_ACC 0x100
+
+#define NAND_CTRL 0xf00
+#define NAND_VERSION 0xf08
+#define NAND_READ_LOCATION_0 0xf20
+#define NAND_READ_LOCATION_1 0xf24
+
+/* dummy register offsets, used by write_reg_dma */
+#define NAND_DEV_CMD1_RESTORE 0xdead
+#define NAND_DEV_CMD_VLD_RESTORE 0xbeef
+
+/* NAND_FLASH_CMD bits */
+#define PAGE_ACC BIT(4)
+#define LAST_PAGE BIT(5)
+
+/* NAND_FLASH_CHIP_SELECT bits */
+#define NAND_DEV_SEL 0
+#define DM_EN BIT(2)
+
+/* NAND_FLASH_STATUS bits */
+#define FS_OP_ERR BIT(4)
+#define FS_READY_BSY_N BIT(5)
+#define FS_MPU_ERR BIT(8)
+#define FS_DEVICE_STS_ERR BIT(16)
+#define FS_DEVICE_WP BIT(23)
+
+/* NAND_BUFFER_STATUS bits */
+#define BS_UNCORRECTABLE_BIT BIT(8)
+#define BS_CORRECTABLE_ERR_MSK 0x1f
+
+/* NAND_DEVn_CFG0 bits */
+#define DISABLE_STATUS_AFTER_WRITE 4
+#define CW_PER_PAGE 6
+#define UD_SIZE_BYTES 9
+#define ECC_PARITY_SIZE_BYTES_RS 19
+#define SPARE_SIZE_BYTES 23
+#define NUM_ADDR_CYCLES 27
+#define STATUS_BFR_READ 30
+#define SET_RD_MODE_AFTER_STATUS 31
+
+/* NAND_DEVn_CFG0 bits */
+#define DEV0_CFG1_ECC_DISABLE 0
+#define WIDE_FLASH 1
+#define NAND_RECOVERY_CYCLES 2
+#define CS_ACTIVE_BSY 5
+#define BAD_BLOCK_BYTE_NUM 6
+#define BAD_BLOCK_IN_SPARE_AREA 16
+#define WR_RD_BSY_GAP 17
+#define ENABLE_BCH_ECC 27
+
+/* NAND_DEV0_ECC_CFG bits */
+#define ECC_CFG_ECC_DISABLE 0
+#define ECC_SW_RESET 1
+#define ECC_MODE 4
+#define ECC_PARITY_SIZE_BYTES_BCH 8
+#define ECC_NUM_DATA_BYTES 16
+#define ECC_FORCE_CLK_OPEN 30
+
+/* NAND_DEV_CMD1 bits */
+#define READ_ADDR 0
+
+/* NAND_DEV_CMD_VLD bits */
+#define READ_START_VLD 0
+
+/* NAND_EBI2_ECC_BUF_CFG bits */
+#define NUM_STEPS 0
+
+/* NAND_ERASED_CW_DETECT_CFG bits */
+#define ERASED_CW_ECC_MASK 1