From 7363cf0581a3e70b3dbd346dec8b7ae652776f80 Mon Sep 17 00:00:00 2001
From: Roger Quadros <rogerq@kernel.org>
Date: Tue, 20 Dec 2022 12:22:03 +0200
Subject: [PATCH] mtd: rawnand: omap_elm: u-boot driver model support

Support u-boot driver model. We still retain
support legacy way of doing things if ELM_BASE
is defined in <asm/arch/hardware.h>

We could completely get rid of that if all
platforms defining ELM_BASE get rid of that definition
and enable CONFIG_SYS_NAND_SELF_INIT and are verified
to work.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Link: https://lore.kernel.org/all/20221220102203.52398-9-rogerq@kernel.org
Link: https://lore.kernel.org/all/CABGWkvrvKiVA_yaDnHJcHEKwc+pEuLdz=i6HQEY0oJQvohCUsw@mail.gmail.com
---
 drivers/mtd/nand/raw/omap_elm.c               | 38 ++++++++++++++++++-
 .../mtd => drivers/mtd/nand/raw}/omap_elm.h   |  6 +++
 drivers/mtd/nand/raw/omap_gpmc.c              | 12 +++++-
 3 files changed, 54 insertions(+), 2 deletions(-)
 rename {include/linux/mtd => drivers/mtd/nand/raw}/omap_elm.h (97%)

diff --git a/drivers/mtd/nand/raw/omap_elm.c b/drivers/mtd/nand/raw/omap_elm.c
index 35c6dd1f1b..56a2c39e4f 100644
--- a/drivers/mtd/nand/raw/omap_elm.c
+++ b/drivers/mtd/nand/raw/omap_elm.c
@@ -15,9 +15,14 @@
 #include <common.h>
 #include <asm/io.h>
 #include <linux/errno.h>
-#include <linux/mtd/omap_elm.h>
 #include <asm/arch/hardware.h>
 
+#include <dm.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+
+#include "omap_elm.h"
+
 #define DRIVER_NAME		"omap-elm"
 #define ELM_DEFAULT_POLY (0)
 
@@ -180,6 +185,7 @@ void elm_reset(void)
 		;
 }
 
+#ifdef ELM_BASE
 /**
  * elm_init - Initialize ELM module
  *
@@ -191,3 +197,33 @@ void elm_init(void)
 	elm_cfg = (struct elm *)ELM_BASE;
 	elm_reset();
 }
+#endif
+
+#if CONFIG_IS_ENABLED(SYS_NAND_SELF_INIT)
+
+static int elm_probe(struct udevice *dev)
+{
+#ifndef ELM_BASE
+	struct resource res;
+
+	dev_read_resource(dev, 0, &res);
+	elm_cfg = devm_ioremap(dev, res.start, resource_size(&res));
+	elm_reset();
+#endif
+
+	return 0;
+}
+
+static const struct udevice_id elm_ids[] = {
+	{ .compatible = "ti,am3352-elm" },
+	{ .compatible = "ti,am64-elm" },
+	{ }
+};
+
+U_BOOT_DRIVER(gpmc_elm) = {
+	.name           = DRIVER_NAME,
+	.id             = UCLASS_MTD,
+	.of_match       = elm_ids,
+	.probe          = elm_probe,
+};
+#endif /* CONFIG_SYS_NAND_SELF_INIT */
diff --git a/include/linux/mtd/omap_elm.h b/drivers/mtd/nand/raw/omap_elm.h
similarity index 97%
rename from include/linux/mtd/omap_elm.h
rename to drivers/mtd/nand/raw/omap_elm.h
index f3db00d55d..a7f7bacb15 100644
--- a/include/linux/mtd/omap_elm.h
+++ b/drivers/mtd/nand/raw/omap_elm.h
@@ -74,6 +74,12 @@ int elm_check_error(u8 *syndrome, enum bch_level bch_type, u32 *error_count,
 		u32 *error_locations);
 int elm_config(enum bch_level level);
 void elm_reset(void);
+#ifdef ELM_BASE
 void elm_init(void);
+#else
+static inline void elm_init(void)
+{
+}
+#endif
 #endif /* __ASSEMBLY__ */
 #endif /* __ASM_ARCH_ELM_H */
diff --git a/drivers/mtd/nand/raw/omap_gpmc.c b/drivers/mtd/nand/raw/omap_gpmc.c
index 4d5f2455df..1a5ed0de31 100644
--- a/drivers/mtd/nand/raw/omap_gpmc.c
+++ b/drivers/mtd/nand/raw/omap_gpmc.c
@@ -20,7 +20,8 @@
 #include <linux/bch.h>
 #include <linux/compiler.h>
 #include <nand.h>
-#include <linux/mtd/omap_elm.h>
+
+#include "omap_elm.h"
 
 #ifndef GPMC_MAX_CS
 #define GPMC_MAX_CS	4
@@ -1249,6 +1250,15 @@ void board_nand_init(void)
 	struct udevice *dev;
 	int ret;
 
+#ifdef CONFIG_NAND_OMAP_ELM
+	ret = uclass_get_device_by_driver(UCLASS_MTD,
+					  DM_DRIVER_GET(gpmc_elm), &dev);
+	if (ret && ret != -ENODEV) {
+		pr_err("%s: Failed to get ELM device: %d\n", __func__, ret);
+		return;
+	}
+#endif
+
 	ret = uclass_get_device_by_driver(UCLASS_MTD,
 					  DM_DRIVER_GET(gpmc_nand), &dev);
 	if (ret && ret != -ENODEV)
-- 
2.39.5