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Add SMI NAND driver
Signed-off-by: Luke Wren <wren6991@gmail.com>
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Diff for: ‎Documentation/devicetree/bindings/mtd/brcm,bcm2835-smi-nand.txt

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* BCM2835 SMI NAND flash
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This driver is a shim between the BCM2835 SMI driver (SMI is a peripheral for
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talking to parallel register interfaces) and Linux's MTD layer.
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Required properties:
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- compatible: "brcm,bcm2835-smi-nand"
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- status: "okay"
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Optional properties:
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- partition@n, where n is an integer from a consecutive sequence starting at 0
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- Difficult to store partition table on NAND device - normally put it
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in the source code, kernel bootparams, or device tree (the best way!)
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- Sub-properties:
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- label: the partition name, as shown by mtdinfo /dev/mtd*
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- reg: the size and offset of this partition.
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- (optional) read-only: an empty property flagging as read only
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Example:
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nand: flash@0 {
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compatible = "brcm,bcm2835-smi-nand";
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status = "okay";
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partition@0 {
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label = "stage2";
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// 128k
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reg = <0 0x20000>;
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read-only;
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};
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partition@1 {
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label = "firmware";
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// 16M
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reg = <0x20000 0x1000000>;
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read-only;
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};
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partition@2 {
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label = "root";
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// 2G
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reg = <0x1020000 0x80000000>;
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};
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};

Diff for: ‎drivers/mtd/nand/Kconfig

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@@ -40,6 +40,13 @@ config MTD_SM_COMMON
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tristate
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default n
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config MTD_NAND_BCM2835_SMI
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tristate "Use Broadcom's Secondary Memory Interface as a NAND controller (BCM283x)"
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depends on BCM2835_SMI
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default m
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help
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Uses the BCM2835's SMI peripheral as a NAND controller.
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config MTD_NAND_DENALI
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tristate
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Diff for: ‎drivers/mtd/nand/Makefile

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@@ -14,6 +14,7 @@ obj-$(CONFIG_MTD_NAND_DENALI) += denali.o
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obj-$(CONFIG_MTD_NAND_DENALI_PCI) += denali_pci.o
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obj-$(CONFIG_MTD_NAND_DENALI_DT) += denali_dt.o
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obj-$(CONFIG_MTD_NAND_AU1550) += au1550nd.o
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obj-$(CONFIG_MTD_NAND_BCM2835_SMI) += bcm2835_smi_nand.o
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obj-$(CONFIG_MTD_NAND_BF5XX) += bf5xx_nand.o
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obj-$(CONFIG_MTD_NAND_S3C2410) += s3c2410.o
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obj-$(CONFIG_MTD_NAND_TANGO) += tango_nand.o

Diff for: ‎drivers/mtd/nand/bcm2835_smi_nand.c

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/**
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* NAND flash driver for Broadcom Secondary Memory Interface
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*
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* Written by Luke Wren <luke@raspberrypi.org>
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* Copyright (c) 2015, Raspberry Pi (Trading) Ltd.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions, and the following disclaimer,
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* without modification.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The names of the above-listed copyright holders may not be used
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* to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* ALTERNATIVELY, this software may be distributed under the terms of the
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* GNU General Public License ("GPL") version 2, as published by the Free
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* Software Foundation.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
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* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/mtd/rawnand.h>
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#include <linux/mtd/partitions.h>
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#include <linux/broadcom/bcm2835_smi.h>
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#define DEVICE_NAME "bcm2835-smi-nand"
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#define DRIVER_NAME "smi-nand-bcm2835"
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struct bcm2835_smi_nand_host {
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struct bcm2835_smi_instance *smi_inst;
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struct nand_chip nand_chip;
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struct mtd_info mtd;
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struct device *dev;
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};
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/****************************************************************************
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*
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* NAND functionality implementation
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*
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****************************************************************************/
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#define SMI_NAND_CLE_PIN 0x01
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#define SMI_NAND_ALE_PIN 0x02
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static inline void bcm2835_smi_nand_cmd_ctrl(struct mtd_info *mtd, int cmd,
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unsigned int ctrl)
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{
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uint32_t cmd32 = cmd;
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uint32_t addr = ~(SMI_NAND_CLE_PIN | SMI_NAND_ALE_PIN);
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struct bcm2835_smi_nand_host *host = dev_get_drvdata(mtd->dev.parent);
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struct bcm2835_smi_instance *inst = host->smi_inst;
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if (ctrl & NAND_CLE)
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addr |= SMI_NAND_CLE_PIN;
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if (ctrl & NAND_ALE)
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addr |= SMI_NAND_ALE_PIN;
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/* Lower ALL the CS pins! */
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if (ctrl & NAND_NCE)
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addr &= (SMI_NAND_CLE_PIN | SMI_NAND_ALE_PIN);
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bcm2835_smi_set_address(inst, addr);
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if (cmd != NAND_CMD_NONE)
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bcm2835_smi_write_buf(inst, &cmd32, 1);
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}
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static inline uint8_t bcm2835_smi_nand_read_byte(struct mtd_info *mtd)
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{
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uint8_t byte;
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struct bcm2835_smi_nand_host *host = dev_get_drvdata(mtd->dev.parent);
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struct bcm2835_smi_instance *inst = host->smi_inst;
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bcm2835_smi_read_buf(inst, &byte, 1);
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return byte;
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}
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static inline void bcm2835_smi_nand_write_byte(struct mtd_info *mtd,
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uint8_t byte)
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{
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struct bcm2835_smi_nand_host *host = dev_get_drvdata(mtd->dev.parent);
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struct bcm2835_smi_instance *inst = host->smi_inst;
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bcm2835_smi_write_buf(inst, &byte, 1);
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}
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static inline void bcm2835_smi_nand_write_buf(struct mtd_info *mtd,
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const uint8_t *buf, int len)
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{
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struct bcm2835_smi_nand_host *host = dev_get_drvdata(mtd->dev.parent);
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struct bcm2835_smi_instance *inst = host->smi_inst;
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bcm2835_smi_write_buf(inst, buf, len);
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}
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static inline void bcm2835_smi_nand_read_buf(struct mtd_info *mtd,
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uint8_t *buf, int len)
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{
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struct bcm2835_smi_nand_host *host = dev_get_drvdata(mtd->dev.parent);
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struct bcm2835_smi_instance *inst = host->smi_inst;
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bcm2835_smi_read_buf(inst, buf, len);
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}
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/****************************************************************************
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*
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* Probe and remove functions
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*
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***************************************************************************/
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static int bcm2835_smi_nand_probe(struct platform_device *pdev)
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{
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struct bcm2835_smi_nand_host *host;
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struct nand_chip *this;
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struct mtd_info *mtd;
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struct device *dev = &pdev->dev;
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struct device_node *node = dev->of_node, *smi_node;
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struct mtd_part_parser_data ppdata;
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struct smi_settings *smi_settings;
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struct bcm2835_smi_instance *smi_inst;
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int ret = -ENXIO;
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if (!node) {
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dev_err(dev, "No device tree node supplied!");
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return -EINVAL;
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}
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smi_node = of_parse_phandle(node, "smi_handle", 0);
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/* Request use of SMI peripheral: */
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smi_inst = bcm2835_smi_get(smi_node);
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if (!smi_inst) {
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dev_err(dev, "Could not register with SMI.");
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return -EPROBE_DEFER;
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}
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/* Set SMI timing and bus width */
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smi_settings = bcm2835_smi_get_settings_from_regs(smi_inst);
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smi_settings->data_width = SMI_WIDTH_8BIT;
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smi_settings->read_setup_time = 2;
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smi_settings->read_hold_time = 1;
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smi_settings->read_pace_time = 1;
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smi_settings->read_strobe_time = 3;
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smi_settings->write_setup_time = 2;
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smi_settings->write_hold_time = 1;
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smi_settings->write_pace_time = 1;
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smi_settings->write_strobe_time = 3;
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bcm2835_smi_set_regs_from_settings(smi_inst);
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host = devm_kzalloc(dev, sizeof(struct bcm2835_smi_nand_host),
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GFP_KERNEL);
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if (!host)
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return -ENOMEM;
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host->dev = dev;
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host->smi_inst = smi_inst;
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platform_set_drvdata(pdev, host);
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/* Link the structures together */
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this = &host->nand_chip;
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mtd = &host->mtd;
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mtd->priv = this;
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mtd->owner = THIS_MODULE;
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mtd->dev.parent = dev;
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mtd->name = DRIVER_NAME;
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/* 20 us command delay time... */
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this->chip_delay = 20;
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this->priv = host;
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this->cmd_ctrl = bcm2835_smi_nand_cmd_ctrl;
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this->read_byte = bcm2835_smi_nand_read_byte;
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this->write_byte = bcm2835_smi_nand_write_byte;
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this->write_buf = bcm2835_smi_nand_write_buf;
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this->read_buf = bcm2835_smi_nand_read_buf;
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this->ecc.mode = NAND_ECC_SOFT;
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/* Should never be accessed directly: */
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this->IO_ADDR_R = (void *)0xdeadbeef;
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this->IO_ADDR_W = (void *)0xdeadbeef;
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/* First scan to find the device and get the page size */
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if (nand_scan_ident(mtd, 1, NULL))
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return -ENXIO;
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/* Second phase scan */
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if (nand_scan_tail(mtd))
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return -ENXIO;
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ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
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if (!ret)
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return 0;
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nand_release(mtd);
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return -EINVAL;
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}
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static int bcm2835_smi_nand_remove(struct platform_device *pdev)
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{
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struct bcm2835_smi_nand_host *host = platform_get_drvdata(pdev);
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nand_release(&host->mtd);
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return 0;
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}
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/****************************************************************************
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*
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* Register the driver with device tree
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*
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***************************************************************************/
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static const struct of_device_id bcm2835_smi_nand_of_match[] = {
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{.compatible = "brcm,bcm2835-smi-nand",},
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{ /* sentinel */ }
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};
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MODULE_DEVICE_TABLE(of, bcm2835_smi_nand_of_match);
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static struct platform_driver bcm2835_smi_nand_driver = {
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.probe = bcm2835_smi_nand_probe,
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.remove = bcm2835_smi_nand_remove,
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.driver = {
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.name = DRIVER_NAME,
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.owner = THIS_MODULE,
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.of_match_table = bcm2835_smi_nand_of_match,
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},
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};
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module_platform_driver(bcm2835_smi_nand_driver);
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MODULE_ALIAS("platform:smi-nand-bcm2835");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION
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("Driver for NAND chips using Broadcom Secondary Memory Interface");
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MODULE_AUTHOR("Luke Wren <luke@raspberrypi.org>");

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