[PATCH 3/4] nvmem: mtk-efuse: replace driver with a generic MMIO one

["Rafał Miłecki" <zajec5@gmail.com>]

From: Rafał Miłecki <rafal@milecki.pl>

Mediatek EFUSE uses a simple MMIO that can be handled with a generic
driver. Replace this driver to avoid code duplication.

Keep Kconfig symbol for a release or two to help with "make oldconfig".

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
 drivers/nvmem/Kconfig     |  7 ++-
 drivers/nvmem/Makefile    |  2 -
 drivers/nvmem/mmio.c      |  3 ++
 drivers/nvmem/mtk-efuse.c | 97 ---------------------------------------
 4 files changed, 6 insertions(+), 103 deletions(-)
 delete mode 100644 drivers/nvmem/mtk-efuse.c

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index 9eb5e93f0455..4d652c7382a6 100644
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -184,12 +184,11 @@ config NVMEM_MTK_EFUSE
 	tristate "Mediatek SoCs EFUSE support"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
 	depends on HAS_IOMEM
+	select NVMEM_MMIO
 	help
-	  This is a driver to access hardware related data like sensor
-	  calibration, HDMI impedance etc.
+	  This driver has been replaced by a generic MMIO implementation.
 
-	  This driver can also be built as a module. If so, the module
-	  will be called efuse-mtk.
+	  Update your config as this symbol will be dropped in the next release.
 
 config NVMEM_MXS_OCOTP
 	tristate "Freescale MXS On-Chip OTP Memory Support"
diff --git a/drivers/nvmem/Makefile b/drivers/nvmem/Makefile
index 2f2bed7cdf24..7a8e29ea408e 100644
--- a/drivers/nvmem/Makefile
+++ b/drivers/nvmem/Makefile
@@ -38,8 +38,6 @@ obj-$(CONFIG_NVMEM_MICROCHIP_OTPC)	+= nvmem-microchip-otpc.o
 nvmem-microchip-otpc-y			:= microchip-otpc.o
 obj-$(CONFIG_NVMEM_MMIO)		+= nvmem-mmio.o
 nvmem-mmio-y				:= mmio.o
-obj-$(CONFIG_NVMEM_MTK_EFUSE)		+= nvmem_mtk-efuse.o
-nvmem_mtk-efuse-y			:= mtk-efuse.o
 obj-$(CONFIG_NVMEM_MXS_OCOTP)		+= nvmem-mxs-ocotp.o
 nvmem-mxs-ocotp-y			:= mxs-ocotp.o
 obj-$(CONFIG_NVMEM_NINTENDO_OTP)	+= nvmem-nintendo-otp.o
diff --git a/drivers/nvmem/mmio.c b/drivers/nvmem/mmio.c
index 19c8880dc675..253ade72e0c3 100644
--- a/drivers/nvmem/mmio.c
+++ b/drivers/nvmem/mmio.c
@@ -57,6 +57,9 @@ static int mmio_nvmem_probe(struct platform_device *pdev)
 
 static const struct of_device_id mmio_nvmem_of_match_table[] = {
 	{ .compatible = "mmio-nvmem", },
+	/* Custom bindings that were introduced before the mmio one */
+	{ .compatible = "mediatek,mt8173-efuse", },
+	{ .compatible = "mediatek,efuse", },
 	{},
 };
 
diff --git a/drivers/nvmem/mtk-efuse.c b/drivers/nvmem/mtk-efuse.c
deleted file mode 100644
index a08e0aedd21c..000000000000
--- a/drivers/nvmem/mtk-efuse.c
+++ /dev/null
@@ -1,97 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (c) 2015 MediaTek Inc.
- * Author: Andrew-CT Chen <andrew-ct.chen@mediatek.com>
- */
-
-#include <linux/device.h>
-#include <linux/module.h>
-#include <linux/mod_devicetable.h>
-#include <linux/io.h>
-#include <linux/nvmem-provider.h>
-#include <linux/platform_device.h>
-
-struct mtk_efuse_priv {
-	void __iomem *base;
-};
-
-static int mtk_reg_read(void *context,
-			unsigned int reg, void *_val, size_t bytes)
-{
-	struct mtk_efuse_priv *priv = context;
-	void __iomem *addr = priv->base + reg;
-	u8 *val = _val;
-	int i;
-
-	for (i = 0; i < bytes; i++, val++)
-		*val = readb(addr + i);
-
-	return 0;
-}
-
-static int mtk_efuse_probe(struct platform_device *pdev)
-{
-	struct device *dev = &pdev->dev;
-	struct resource *res;
-	struct nvmem_device *nvmem;
-	struct nvmem_config econfig = {};
-	struct mtk_efuse_priv *priv;
-
-	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
-
-	priv->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
-	if (IS_ERR(priv->base))
-		return PTR_ERR(priv->base);
-
-	econfig.stride = 1;
-	econfig.word_size = 1;
-	econfig.reg_read = mtk_reg_read;
-	econfig.size = resource_size(res);
-	econfig.priv = priv;
-	econfig.dev = dev;
-	nvmem = devm_nvmem_register(dev, &econfig);
-
-	return PTR_ERR_OR_ZERO(nvmem);
-}
-
-static const struct of_device_id mtk_efuse_of_match[] = {
-	{ .compatible = "mediatek,mt8173-efuse",},
-	{ .compatible = "mediatek,efuse",},
-	{/* sentinel */},
-};
-MODULE_DEVICE_TABLE(of, mtk_efuse_of_match);
-
-static struct platform_driver mtk_efuse_driver = {
-	.probe = mtk_efuse_probe,
-	.driver = {
-		.name = "mediatek,efuse",
-		.of_match_table = mtk_efuse_of_match,
-	},
-};
-
-static int __init mtk_efuse_init(void)
-{
-	int ret;
-
-	ret = platform_driver_register(&mtk_efuse_driver);
-	if (ret) {
-		pr_err("Failed to register efuse driver\n");
-		return ret;
-	}
-
-	return 0;
-}
-
-static void __exit mtk_efuse_exit(void)
-{
-	return platform_driver_unregister(&mtk_efuse_driver);
-}
-
-subsys_initcall(mtk_efuse_init);
-module_exit(mtk_efuse_exit);
-
-MODULE_AUTHOR("Andrew-CT Chen <andrew-ct.chen@mediatek.com>");
-MODULE_DESCRIPTION("Mediatek EFUSE driver");
-MODULE_LICENSE("GPL v2");
-- 
2.34.1