mtd: Fix misuses of of_match_ptr()

of_match_ptr() either expands to NULL if !CONFIG_OF, or is transparent
otherwise. There are several drivers using this macro which keep their
of_device_id array enclosed within an #ifdef CONFIG_OF check, these are
considered fine. However, When misused, the of_device_id array pointed
by this macro will produce a warning because it is finally unused when
compiled without OF support.

A number of fixes are possible:
- Always depend on CONFIG_OF, but this will not always work and may
  break boards.
- Enclose the compatible array by #ifdef's, this may save a bit of
  memory but will reduce build coverage.
- Tell the compiler the array may be unused, if this can be avoided,
  let's not do this.
- Just drop the macro, setting the of_device_id array for a non OF
  enabled platform is not an issue, it will just be unused.

The latter solution seems the more appropriate, so let's use it.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Pratyush Yadav <p.yadav@ti.com>
Link: https://lore.kernel.org/linux-mtd/20220127110631.1064705-1-miquel.raynal@bootlin.com

drivers/mtd/devices/mchp23k256.c

@@ -234,7 +234,7 @@ MODULE_DEVICE_TABLE(of, mchp23k256_of_table);
 static struct spi_driver mchp23k256_driver = {
 	.driver = {
 		.name	= "mchp23k256",
-		.of_match_table = of_match_ptr(mchp23k256_of_table),
+		.of_match_table = mchp23k256_of_table,
 	},
 	.probe		= mchp23k256_probe,
 	.remove		= mchp23k256_remove,

drivers/mtd/devices/mchp48l640.c

@@ -362,7 +362,7 @@ MODULE_DEVICE_TABLE(of, mchp48l640_of_table);
 static struct spi_driver mchp48l640_driver = {
 	.driver = {
 		.name	= "mchp48l640",
-		.of_match_table = of_match_ptr(mchp48l640_of_table),
+		.of_match_table = mchp48l640_of_table,
 	},
 	.probe		= mchp48l640_probe,
 	.remove		= mchp48l640_remove,

drivers/mtd/nand/raw/atmel/nand-controller.c

@@ -2648,7 +2648,7 @@ static SIMPLE_DEV_PM_OPS(atmel_nand_controller_pm_ops, NULL,
 static struct platform_driver atmel_nand_controller_driver = {
 	.driver = {
 		.name = "atmel-nand-controller",
-		.of_match_table = of_match_ptr(atmel_nand_controller_of_ids),
+		.of_match_table = atmel_nand_controller_of_ids,
 		.pm = &atmel_nand_controller_pm_ops,
 	},
 	.probe = atmel_nand_controller_probe,

drivers/mtd/nand/raw/atmel/pmecc.c

@@ -1003,7 +1003,7 @@ static int atmel_pmecc_probe(struct platform_device *pdev)
 static struct platform_driver atmel_pmecc_driver = {
 	.driver = {
 		.name = "atmel-pmecc",
-		.of_match_table = of_match_ptr(atmel_pmecc_match),
+		.of_match_table = atmel_pmecc_match,
 	},
 	.probe = atmel_pmecc_probe,
 };

drivers/mtd/nand/raw/ingenic/ingenic_nand_drv.c

@@ -567,7 +567,7 @@ static struct platform_driver ingenic_nand_driver = {
 	.remove		= ingenic_nand_remove,
 	.driver	= {
 		.name	= DRV_NAME,
-		.of_match_table = of_match_ptr(ingenic_nand_dt_match),
+		.of_match_table = ingenic_nand_dt_match,
 	},
 };
 module_platform_driver(ingenic_nand_driver);

drivers/mtd/nand/raw/ingenic/jz4780_bch.c

@@ -260,7 +260,7 @@ static struct platform_driver jz4780_bch_driver = {
 	.probe		= jz4780_bch_probe,
 	.driver	= {
 		.name	= "jz4780-bch",
-		.of_match_table = of_match_ptr(jz4780_bch_dt_match),
+		.of_match_table = jz4780_bch_dt_match,
 	},
 };
 module_platform_driver(jz4780_bch_driver);

drivers/mtd/nand/raw/mtk_ecc.c

@@ -579,7 +579,7 @@ static struct platform_driver mtk_ecc_driver = {
 	.probe  = mtk_ecc_probe,
 	.driver = {
 		.name  = "mtk-ecc",
-		.of_match_table = of_match_ptr(mtk_ecc_dt_match),
+		.of_match_table = mtk_ecc_dt_match,
 #ifdef CONFIG_PM_SLEEP
 		.pm = &mtk_ecc_pm_ops,
 #endif

drivers/mtd/nand/raw/omap2.c

@@ -2298,7 +2298,7 @@ static struct platform_driver omap_nand_driver = {
 	.remove		= omap_nand_remove,
 	.driver		= {
 		.name	= DRIVER_NAME,
-		.of_match_table = of_match_ptr(omap_nand_ids),
+		.of_match_table = omap_nand_ids,
 	},
 };
 

drivers/mtd/nand/raw/renesas-nand-controller.c

@@ -1412,7 +1412,7 @@ MODULE_DEVICE_TABLE(of, rnandc_id_table);
 static struct platform_driver rnandc_driver = {
 	.driver = {
 		.name = "renesas-nandc",
-		.of_match_table = of_match_ptr(rnandc_id_table),
+		.of_match_table = rnandc_id_table,
 	},
 	.probe = rnandc_probe,
 	.remove = rnandc_remove,

drivers/mtd/nand/raw/sh_flctl.c

@@ -1220,7 +1220,7 @@ static struct platform_driver flctl_driver = {
 	.remove		= flctl_remove,
 	.driver = {
 		.name	= "sh_flctl",
-		.of_match_table = of_match_ptr(of_flctl_match),
+		.of_match_table = of_flctl_match,
 	},
 };