memory: omap-gpmc: Allow building as a module

Allow OMAP_GPMC to be built as a module.

When building this driver as a module, the symbol
'of_default_bus_match_table' will not be found as it is not being
exported.

The of_match_node() call is redundant anyways as
of_platform_default_populate() already takes care of matching with
'of_default_bus_match_table'. So get rid of that call. This will also
resolve the module build failure.

Move compatible match table to the end where it is usually expected.
Signed-off-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20220426082611.24427-3-rogerq@kernel.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

drivers/memory/Kconfig

@@ -103,7 +103,7 @@ config TI_EMIF
 	  temperature changes
 
 config OMAP_GPMC
-	bool "Texas Instruments OMAP SoC GPMC driver"
+	tristate "Texas Instruments OMAP SoC GPMC driver"
 	depends on OF_ADDRESS
 	select GPIOLIB
 	help

drivers/memory/omap-gpmc.c

@@ -12,6 +12,7 @@
 #include <linux/cpu_pm.h>
 #include <linux/irq.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/init.h>
 #include <linux/err.h>
 #include <linux/clk.h>
@@ -1889,16 +1890,6 @@ int gpmc_cs_program_settings(int cs, struct gpmc_settings *p)
 }
 
 #ifdef CONFIG_OF
-static const struct of_device_id gpmc_dt_ids[] = {
-	{ .compatible = "ti,omap2420-gpmc" },
-	{ .compatible = "ti,omap2430-gpmc" },
-	{ .compatible = "ti,omap3430-gpmc" },	/* omap3430 & omap3630 */
-	{ .compatible = "ti,omap4430-gpmc" },	/* omap4430 & omap4460 & omap543x */
-	{ .compatible = "ti,am3352-gpmc" },	/* am335x devices */
-	{ .compatible = "ti,am64-gpmc" },
-	{ }
-};
-
 static void gpmc_cs_set_name(int cs, const char *name)
 {
 	struct gpmc_cs_data *gpmc = &gpmc_cs[cs];
@@ -2257,8 +2248,6 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
 	if (!of_platform_device_create(child, NULL, &pdev->dev))
 		goto err_child_fail;
 
-	/* is child a common bus? */
-	if (of_match_node(of_default_bus_match_table, child))
 	/* create children and other common bus children */
 	if (of_platform_default_populate(child, NULL, &pdev->dev))
 		goto err_child_fail;
@@ -2278,6 +2267,8 @@ static int gpmc_probe_generic_child(struct platform_device *pdev,
 	return ret;
 }
 
+static const struct of_device_id gpmc_dt_ids[];
+
 static int gpmc_probe_dt(struct platform_device *pdev)
 {
 	int ret;
@@ -2644,6 +2635,19 @@ static int gpmc_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(gpmc_pm_ops, gpmc_suspend, gpmc_resume);
 
+#ifdef CONFIG_OF
+static const struct of_device_id gpmc_dt_ids[] = {
+	{ .compatible = "ti,omap2420-gpmc" },
+	{ .compatible = "ti,omap2430-gpmc" },
+	{ .compatible = "ti,omap3430-gpmc" },	/* omap3430 & omap3630 */
+	{ .compatible = "ti,omap4430-gpmc" },	/* omap4430 & omap4460 & omap543x */
+	{ .compatible = "ti,am3352-gpmc" },	/* am335x devices */
+	{ .compatible = "ti,am64-gpmc" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, gpmc_dt_ids);
+#endif
+
 static struct platform_driver gpmc_driver = {
 	.probe		= gpmc_probe,
 	.remove		= gpmc_remove,
@@ -2654,8 +2658,7 @@ static struct platform_driver gpmc_driver = {
 	},
 };
 
-static __init int gpmc_init(void)
-{
-	return platform_driver_register(&gpmc_driver);
-}
-postcore_initcall(gpmc_init);
+module_platform_driver(gpmc_driver);
+
+MODULE_DESCRIPTION("Texas Instruments GPMC driver");
+MODULE_LICENSE("GPL");