[PATCH v5 05/36] memory: tegra30-emc: Make driver modular

Dmitry Osipenko
2020-08-14T00:07:21Z

This patch adds modularization support to the Tegra30 EMC driver. Driver
now can be compiled as a loadable kernel module.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/memory/tegra/Kconfig | 2 +-
drivers/memory/tegra/mc.c | 3 +++
drivers/memory/tegra/tegra30-emc.c | 17 ++++++++++++-----
3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index 7e0e1ef87763..bd453de9d446 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -18,7 +18,7 @@ config TEGRA20_EMC
external memory.

config TEGRA30_EMC
- bool "NVIDIA Tegra30 External Memory Controller driver"
+ tristate "NVIDIA Tegra30 External Memory Controller driver"
default y
depends on TEGRA_MC && ARCH_TEGRA_3x_SOC
help
diff --git a/drivers/memory/tegra/mc.c b/drivers/memory/tegra/mc.c
index ec8403557ed4..772aa021b5f6 100644
--- a/drivers/memory/tegra/mc.c
+++ b/drivers/memory/tegra/mc.c
@@ -6,6 +6,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
+#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -298,6 +299,7 @@ int tegra_mc_write_emem_configuration(struct tegra_mc *mc, unsigned long rate)

return 0;
}
+EXPORT_SYMBOL_GPL(tegra_mc_write_emem_configuration);

unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)
{
@@ -309,6 +311,7 @@ unsigned int tegra_mc_get_emem_device_count(struct tegra_mc *mc)

return dram_count;
}
+EXPORT_SYMBOL_GPL(tegra_mc_get_emem_device_count);

static int load_one_timing(struct tegra_mc *mc,
struct tegra_mc_timing *timing,
diff --git a/drivers/memory/tegra/tegra30-emc.c b/drivers/memory/tegra/tegra30-emc.c
index e448a55cb812..f3082964cfb6 100644
--- a/drivers/memory/tegra/tegra30-emc.c
+++ b/drivers/memory/tegra/tegra30-emc.c
@@ -1343,6 +1343,13 @@ 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:
@@ -1393,6 +1400,7 @@ static const struct of_device_id tegra_emc_of_match[] = {
{ .compatible = "nvidia,tegra30-emc", },
{},
};
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);

static struct platform_driver tegra_emc_driver = {
.probe = tegra_emc_probe,
@@ -1403,9 +1411,8 @@ 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 Tegra30 EMC driver");
+MODULE_LICENSE("GPL v2");
--
2.27.0