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authorDmitry Osipenko <digetx@gmail.com>2020-12-28 18:49:16 +0300
committerKrzysztof Kozlowski <krzk@kernel.org>2021-01-05 20:00:09 +0300
commit281462e593483350d8072a118c6e072c550a80fa (patch)
treeaedb622d4b8e73213c869eae85999fe03cced566 /drivers/memory
parent5c8fe583cce542aa0b84adc939ce85293de36e5e (diff)
downloadlinux-281462e593483350d8072a118c6e072c550a80fa.tar.xz
memory: tegra124-emc: Make driver modular
Add modularization support to the Tegra124 EMC driver, which now can be compiled as a loadable kernel module. Note that EMC clock must be registered at clk-init time, otherwise PLLM will be disabled as unused clock at boot time if EMC driver is compiled as a module. Hence add a prepare/complete callbacks. similarly to what is done for the Tegra20/30 EMC drivers. Tested-by: Nicolas Chauvet <kwizart@gmail.com> Signed-off-by: Dmitry Osipenko <digetx@gmail.com> Link: https://lore.kernel.org/r/20201228154920.18846-2-digetx@gmail.com Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Diffstat (limited to 'drivers/memory')
-rw-r--r--drivers/memory/tegra/Kconfig3
-rw-r--r--drivers/memory/tegra/tegra124-emc.c31
2 files changed, 23 insertions, 11 deletions
diff --git a/drivers/memory/tegra/Kconfig b/drivers/memory/tegra/Kconfig
index ca7077a06f4c..f5b451403c58 100644
--- a/drivers/memory/tegra/Kconfig
+++ b/drivers/memory/tegra/Kconfig
@@ -32,9 +32,10 @@ config TEGRA30_EMC
external memory.
config TEGRA124_EMC
- bool "NVIDIA Tegra124 External Memory Controller driver"
+ tristate "NVIDIA Tegra124 External Memory Controller driver"
default y
depends on TEGRA_MC && ARCH_TEGRA_124_SOC
+ select TEGRA124_CLK_EMC
help
This driver is for the External Memory Controller (EMC) found on
Tegra124 chips. The EMC controls the external DRAM on the board.
diff --git a/drivers/memory/tegra/tegra124-emc.c b/drivers/memory/tegra/tegra124-emc.c
index ee8ee39e98ed..edfbf6d6d357 100644
--- a/drivers/memory/tegra/tegra124-emc.c
+++ b/drivers/memory/tegra/tegra124-emc.c
@@ -9,16 +9,17 @@
#include <linux/clk-provider.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
+#include <linux/clk/tegra.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/io.h>
+#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/sort.h>
#include <linux/string.h>
-#include <soc/tegra/emc.h>
#include <soc/tegra/fuse.h>
#include <soc/tegra/mc.h>
@@ -562,8 +563,8 @@ static struct emc_timing *tegra_emc_find_timing(struct tegra_emc *emc,
return timing;
}
-int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
- unsigned long rate)
+static int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
+ unsigned long rate)
{
struct emc_timing *timing = tegra_emc_find_timing(emc, rate);
struct emc_timing *last = &emc->last_timing;
@@ -790,8 +791,8 @@ int tegra_emc_prepare_timing_change(struct tegra_emc *emc,
return 0;
}
-void tegra_emc_complete_timing_change(struct tegra_emc *emc,
- unsigned long rate)
+static void tegra_emc_complete_timing_change(struct tegra_emc *emc,
+ unsigned long rate)
{
struct emc_timing *timing = tegra_emc_find_timing(emc, rate);
struct emc_timing *last = &emc->last_timing;
@@ -987,6 +988,7 @@ static const struct of_device_id tegra_emc_of_match[] = {
{ .compatible = "nvidia,tegra132-emc" },
{}
};
+MODULE_DEVICE_TABLE(of, tegra_emc_of_match);
static struct device_node *
tegra_emc_find_node_by_ram_code(struct device_node *node, u32 ram_code)
@@ -1226,9 +1228,19 @@ static int tegra_emc_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, emc);
+ tegra124_clk_set_emc_callbacks(tegra_emc_prepare_timing_change,
+ tegra_emc_complete_timing_change);
+
if (IS_ENABLED(CONFIG_DEBUG_FS))
emc_debugfs_init(&pdev->dev, 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;
};
@@ -1240,9 +1252,8 @@ static struct platform_driver tegra_emc_driver = {
.suppress_bind_attrs = true,
},
};
+module_platform_driver(tegra_emc_driver);
-static int tegra_emc_init(void)
-{
- return platform_driver_register(&tegra_emc_driver);
-}
-subsys_initcall(tegra_emc_init);
+MODULE_AUTHOR("Mikko Perttunen <mperttunen@nvidia.com>");
+MODULE_DESCRIPTION("NVIDIA Tegra124 EMC driver");
+MODULE_LICENSE("GPL v2");