nand: oxnas_nand: remove obsolete raw nand driver

Due to lack of maintenance and stall of development for a few years now,
and since no new features will ever be added upstream, remove support
for OX810 and OX820 nand.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20230630-topic-oxnas-upstream-remove-v2-5-fb6ab3dea87c@linaro.org

drivers/mtd/nand/raw/Kconfig

@@ -204,13 +204,6 @@ config MTD_NAND_BCM47XXNFLASH
 	  registered by bcma as platform devices. This enables driver for
 	  NAND flash memories. For now only BCM4706 is supported.
 
-config MTD_NAND_OXNAS
-	tristate "Oxford Semiconductor NAND controller"
-	depends on ARCH_OXNAS || COMPILE_TEST
-	depends on HAS_IOMEM
-	help
-	  This enables the NAND flash controller on Oxford Semiconductor SoCs.
-
 config MTD_NAND_MPC5121_NFC
 	tristate "MPC5121 NAND controller"
 	depends on PPC_MPC512x

drivers/mtd/nand/raw/Makefile

@@ -26,7 +26,6 @@ obj-$(CONFIG_MTD_NAND_MARVELL)		+= marvell_nand.o
 obj-$(CONFIG_MTD_NAND_PLATFORM)		+= plat_nand.o
 obj-$(CONFIG_MTD_NAND_PASEMI)		+= pasemi_nand.o
 obj-$(CONFIG_MTD_NAND_ORION)		+= orion_nand.o
-obj-$(CONFIG_MTD_NAND_OXNAS)		+= oxnas_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_ELBC)		+= fsl_elbc_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_IFC)		+= fsl_ifc_nand.o
 obj-$(CONFIG_MTD_NAND_FSL_UPM)		+= fsl_upm.o

drivers/mtd/nand/raw/oxnas_nand.c

-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Oxford Semiconductor OXNAS NAND driver
-
- * Copyright (C) 2016 Neil Armstrong <narmstrong@baylibre.com>
- * Heavily based on plat_nand.c :
- * Author: Vitaly Wool <vitalywool@gmail.com>
- * Copyright (C) 2013 Ma Haijun <mahaijuns@gmail.com>
- * Copyright (C) 2012 John Crispin <blogic@openwrt.org>
- */
-
-#include <linux/err.h>
-#include <linux/io.h>
-#include <linux/module.h>
-#include <linux/platform_device.h>
-#include <linux/slab.h>
-#include <linux/clk.h>
-#include <linux/reset.h>
-#include <linux/mtd/mtd.h>
-#include <linux/mtd/rawnand.h>
-#include <linux/mtd/partitions.h>
-#include <linux/of.h>
-
-/* Nand commands */
-#define OXNAS_NAND_CMD_ALE		BIT(18)
-#define OXNAS_NAND_CMD_CLE		BIT(19)
-
-#define OXNAS_NAND_MAX_CHIPS	1
-
-struct oxnas_nand_ctrl {
-	struct nand_controller base;
-	void __iomem *io_base;
-	struct clk *clk;
-	struct nand_chip *chips[OXNAS_NAND_MAX_CHIPS];
-	unsigned int nchips;
-};
-
-static uint8_t oxnas_nand_read_byte(struct nand_chip *chip)
-{
-	struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
-
-	return readb(oxnas->io_base);
-}
-
-static void oxnas_nand_read_buf(struct nand_chip *chip, u8 *buf, int len)
-{
-	struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
-
-	ioread8_rep(oxnas->io_base, buf, len);
-}
-
-static void oxnas_nand_write_buf(struct nand_chip *chip, const u8 *buf,
-				 int len)
-{
-	struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
-
-	iowrite8_rep(oxnas->io_base, buf, len);
-}
-
-/* Single CS command control */
-static void oxnas_nand_cmd_ctrl(struct nand_chip *chip, int cmd,
-				unsigned int ctrl)
-{
-	struct oxnas_nand_ctrl *oxnas = nand_get_controller_data(chip);
-
-	if (ctrl & NAND_CLE)
-		writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_CLE);
-	else if (ctrl & NAND_ALE)
-		writeb(cmd, oxnas->io_base + OXNAS_NAND_CMD_ALE);
-}
-
-/*
- * Probe for the NAND device.
- */
-static int oxnas_nand_probe(struct platform_device *pdev)
-{
-	struct device_node *np = pdev->dev.of_node;
-	struct device_node *nand_np;
-	struct oxnas_nand_ctrl *oxnas;
-	struct nand_chip *chip;
-	struct mtd_info *mtd;
-	int count = 0;
-	int err = 0;
-	int i;
-
-	/* Allocate memory for the device structure (and zero it) */
-	oxnas = devm_kzalloc(&pdev->dev, sizeof(*oxnas),
-			     GFP_KERNEL);
-	if (!oxnas)
-		return -ENOMEM;
-
-	nand_controller_init(&oxnas->base);
-
-	oxnas->io_base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(oxnas->io_base))
-		return PTR_ERR(oxnas->io_base);
-
-	oxnas->clk = devm_clk_get(&pdev->dev, NULL);
-	if (IS_ERR(oxnas->clk))
-		oxnas->clk = NULL;
-
-	/* Only a single chip node is supported */
-	count = of_get_child_count(np);
-	if (count > 1)
-		return -EINVAL;
-
-	err = clk_prepare_enable(oxnas->clk);
-	if (err)
-		return err;
-
-	device_reset_optional(&pdev->dev);
-
-	for_each_child_of_node(np, nand_np) {
-		chip = devm_kzalloc(&pdev->dev, sizeof(struct nand_chip),
-				    GFP_KERNEL);
-		if (!chip) {
-			err = -ENOMEM;
-			goto err_release_child;
-		}
-
-		chip->controller = &oxnas->base;
-
-		nand_set_flash_node(chip, nand_np);
-		nand_set_controller_data(chip, oxnas);
-
-		mtd = nand_to_mtd(chip);
-		mtd->dev.parent = &pdev->dev;
-		mtd->priv = chip;
-
-		chip->legacy.cmd_ctrl = oxnas_nand_cmd_ctrl;
-		chip->legacy.read_buf = oxnas_nand_read_buf;
-		chip->legacy.read_byte = oxnas_nand_read_byte;
-		chip->legacy.write_buf = oxnas_nand_write_buf;
-		chip->legacy.chip_delay = 30;
-
-		/* Scan to find existence of the device */
-		err = nand_scan(chip, 1);
-		if (err)
-			goto err_release_child;
-
-		err = mtd_device_register(mtd, NULL, 0);
-		if (err)
-			goto err_cleanup_nand;
-
-		oxnas->chips[oxnas->nchips++] = chip;
-	}
-
-	/* Exit if no chips found */
-	if (!oxnas->nchips) {
-		err = -ENODEV;
-		goto err_clk_unprepare;
-	}
-
-	platform_set_drvdata(pdev, oxnas);
-
-	return 0;
-
-err_cleanup_nand:
-	nand_cleanup(chip);
-err_release_child:
-	of_node_put(nand_np);
-
-	for (i = 0; i < oxnas->nchips; i++) {
-		chip = oxnas->chips[i];
-		WARN_ON(mtd_device_unregister(nand_to_mtd(chip)));
-		nand_cleanup(chip);
-	}
-
-err_clk_unprepare:
-	clk_disable_unprepare(oxnas->clk);
-	return err;
-}
-
-static void oxnas_nand_remove(struct platform_device *pdev)
-{
-	struct oxnas_nand_ctrl *oxnas = platform_get_drvdata(pdev);
-	struct nand_chip *chip;
-	int i;
-
-	for (i = 0; i < oxnas->nchips; i++) {
-		chip = oxnas->chips[i];
-		WARN_ON(mtd_device_unregister(nand_to_mtd(chip)));
-		nand_cleanup(chip);
-	}
-
-	clk_disable_unprepare(oxnas->clk);
-}
-
-static const struct of_device_id oxnas_nand_match[] = {
-	{ .compatible = "oxsemi,ox820-nand" },
-	{},
-};
-MODULE_DEVICE_TABLE(of, oxnas_nand_match);
-
-static struct platform_driver oxnas_nand_driver = {
-	.probe	= oxnas_nand_probe,
-	.remove_new = oxnas_nand_remove,
-	.driver	= {
-		.name		= "oxnas_nand",
-		.of_match_table = oxnas_nand_match,
-	},
-};
-
-module_platform_driver(oxnas_nand_driver);
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
-MODULE_DESCRIPTION("Oxnas NAND driver");
-MODULE_ALIAS("platform:oxnas_nand");