memory: tegra20-emc: Make driver modular

Add modularization support to the Tegra20 EMC driver, which now can be
compiled as a loadable kernel module.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/r/20201104164923.21238-34-digetx@gmail.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index b38e525..ff42674 100644 (file)
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -9,7 +9,7 @@ config TEGRA_MC
          NVIDIA Tegra SoCs.
 
 config TEGRA20_EMC
-       bool "NVIDIA Tegra20 External Memory Controller driver"
+       tristate "NVIDIA Tegra20 External Memory Controller driver"
        default y
        depends on ARCH_TEGRA_2x_SOC
        help

diff --git a/drivers/memory/tegra/tegra20-emc.c b/drivers/memory/tegra/tegra20-emc.c
index c9fe58a..88619e3 100644 (file)
--- a/drivers/memory/tegra/tegra20-emc.c
+++ b/drivers/memory/tegra/tegra20-emc.c
@@ -721,6 +721,13 @@ static int tegra_emc_probe(struct platform_device *pdev)
        platform_set_drvdata(pdev, emc);
        tegra_emc_debugfs_init(emc);
 
+       /*
+        * Don't allow the kernel module to be unloaded. Unloading adds some
+        * extra complexity which doesn't really worth the effort in a case of
+        * this driver.
+        */
+       try_module_get(THIS_MODULE);
+
        return 0;
 
 unset_cb:
@@ -733,6 +740,7 @@ static const struct of_device_id tegra_emc_of_match[] = {
        { .compatible = "nvidia,tegra20-emc", },
        {},
 };
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
 
 static struct platform_driver tegra_emc_driver = {
        .probe = tegra_emc_probe,
@@ -742,9 +750,8 @@ static struct platform_driver tegra_emc_driver = {
                .suppress_bind_attrs = true,
        },
 };
+module_platform_driver(tegra_emc_driver);
 
-static int __init tegra_emc_init(void)
-{
-       return platform_driver_register(&tegra_emc_driver);
-}
-subsys_initcall(tegra_emc_init);
+MODULE_AUTHOR("Dmitry Osipenko <digetx@gmail.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra20 EMC driver");
+MODULE_LICENSE("GPL v2");