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From:   Yong Wu <yong.wu@mediatek.com>
To:     Joerg Roedel <joro@8bytes.org>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        Will Deacon <will@kernel.org>
CC:     Robin Murphy <robin.murphy@arm.com>,
        Tomasz Figa <tfiga@chromium.org>,
        <linux-mediatek@lists.infradead.org>,
        <srv_heupstream@mediatek.com>, <linux-kernel@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <iommu@lists.linux-foundation.org>,
        Krzysztof Kozlowski <krzk@kernel.org>, <yong.wu@mediatek.com>,
        <youlin.pei@mediatek.com>, Nicolas Boichat <drinkcat@chromium.org>,
        <anan.sun@mediatek.com>, <chao.hao@mediatek.com>
Subject: [PATCH v2 2/2] iommu/mediatek: Allow building as module
Date:   Fri, 26 Mar 2021 11:23:37 +0800
Message-ID: <20210326032337.24578-2-yong.wu@mediatek.com>
In-Reply-To: <20210326032337.24578-1-yong.wu@mediatek.com>
References: <20210326032337.24578-1-yong.wu@mediatek.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The IOMMU in many SoC depends on the MM clocks and power-domain which
are device_initcall normally, thus the subsys_init here is not helpful.
This patch switches it to module_platform_driver which also allow the
driver built as module.

Correspondingly switch the config to tristate, and update the
iommu_ops's owner.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/Kconfig     |  2 +-
 drivers/iommu/mtk_iommu.c | 17 +++++------------
 2 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index bc93da48bed0..74f3e15edc14 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -349,7 +349,7 @@ config S390_AP_IOMMU
 	  is not implemented as it is not necessary for VFIO.
 
 config MTK_IOMMU
-	bool "MTK IOMMU Support"
+	tristate "MediaTek IOMMU Support"
 	depends on ARCH_MEDIATEK || COMPILE_TEST
 	select ARM_DMA_USE_IOMMU
 	select IOMMU_API
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 6ecc007f07cd..75375935f301 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -17,6 +17,7 @@
 #include <linux/iopoll.h>
 #include <linux/list.h>
 #include <linux/mfd/syscon.h>
+#include <linux/module.h>
 #include <linux/of_address.h>
 #include <linux/of_iommu.h>
 #include <linux/of_irq.h>
@@ -683,6 +684,7 @@ static const struct iommu_ops mtk_iommu_ops = {
 	.get_resv_regions = mtk_iommu_get_resv_regions,
 	.put_resv_regions = generic_iommu_put_resv_regions,
 	.pgsize_bitmap	= SZ_4K | SZ_64K | SZ_1M | SZ_16M,
+	.owner		= THIS_MODULE,
 };
 
 static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
@@ -1079,16 +1081,7 @@ static struct platform_driver mtk_iommu_driver = {
 		.pm = &mtk_iommu_pm_ops,
 	}
 };
+module_platform_driver(mtk_iommu_driver);
 
-static int __init mtk_iommu_init(void)
-{
-	int ret;
-
-	ret = platform_driver_register(&mtk_iommu_driver);
-	if (ret != 0)
-		pr_err("Failed to register MTK IOMMU driver\n");
-
-	return ret;
-}
-
-subsys_initcall(mtk_iommu_init)
+MODULE_DESCRIPTION("IOMMU API for MediaTek M4U implementations");
+MODULE_LICENSE("GPL v2");
-- 
2.18.0