[PATCH 1/2] mtd: move code reading DT specified part probes to the common place

[Rafał Miłecki]

From: Rafał Miłecki <rafal at milecki.pl>

Handling (creating) partitions for flash devices requires using a proper
driver that will read partition table (out of somewhere). We can't
simply try all existing drivers one by one, so MTD subsystem allows
drivers to specify a list of applicable part probes.

So far physmap_of was the only driver with support for linux,part-probe
DT property. Other ones had list or probes hardcoded which wasn't making
them really flexible. It prevented using common flash drivers on
platforms that required some specific partition table access.

This commit moves support for mentioned DT property to the common place
so it can be reused by other drivers.

Signed-off-by: Rafał Miłecki <rafal at milecki.pl>
---
This patch is based on top of
[PATCH] mtd: physmap_of: use OF helpers for reading strings
---
 drivers/mtd/maps/physmap_of.c | 39 ++++++---------------------------------
 drivers/of/Kconfig            |  6 ++++++
 drivers/of/Makefile           |  1 +
 drivers/of/of_mtd.c           | 30 ++++++++++++++++++++++++++++++
 include/linux/of_mtd.h        | 25 +++++++++++++++++++++++++
 5 files changed, 68 insertions(+), 33 deletions(-)
 create mode 100644 drivers/of/of_mtd.c
 create mode 100644 include/linux/of_mtd.h

diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index 62fa6836f218..fa54c07eb118 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -22,6 +22,7 @@
 #include <linux/mtd/concat.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_mtd.h>
 #include <linux/of_platform.h>
 #include <linux/slab.h>
 #include "physmap_of_gemini.h"
@@ -114,33 +115,6 @@ static struct mtd_info *obsolete_probe(struct platform_device *dev,
 static const char * const part_probe_types_def[] = {
 	"cmdlinepart", "RedBoot", "ofpart", "ofoldpart", NULL };
 
-static const char * const *of_get_probes(struct device_node *dp)
-{
-	const char **res;
-	int count;
-
-	count = of_property_count_strings(dp, "linux,part-probe");
-	if (count < 0)
-		return part_probe_types_def;
-
-	res = kzalloc((count + 1) * sizeof(*res), GFP_KERNEL);
-	if (!res)
-		return NULL;
-
-	count = of_property_read_string_array(dp, "linux,part-probe", res,
-					      count);
-	if (count < 0)
-		return NULL;
-
-	return res;
-}
-
-static void of_free_probes(const char * const *probes)
-{
-	if (probes != part_probe_types_def)
-		kfree(probes);
-}
-
 static const struct of_device_id of_flash_match[];
 static int of_flash_probe(struct platform_device *dev)
 {
@@ -310,14 +284,13 @@ static int of_flash_probe(struct platform_device *dev)
 
 	info->cmtd->dev.parent = &dev->dev;
 	mtd_set_of_node(info->cmtd, dp);
-	part_probe_types = of_get_probes(dp);
-	if (!part_probe_types) {
-		err = -ENOMEM;
-		goto err_out;
-	}
+	part_probe_types = of_mtd_get_probes(dp);
+	if (!part_probe_types)
+		part_probe_types = part_probe_types_def;
 	mtd_device_parse_register(info->cmtd, part_probe_types, NULL,
 			NULL, 0);
-	of_free_probes(part_probe_types);
+	if (part_probe_types != part_probe_types_def)
+		of_mtd_free_probes(part_probe_types);
 
 	kfree(mtd_list);
 
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index ba7b034b2b91..18ac835a1ce4 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -78,6 +78,12 @@ config OF_MDIO
 	help
 	  OpenFirmware MDIO bus (Ethernet PHY) accessors
 
+config OF_MTD
+	def_tristate MTD
+	depends on MTD
+	help
+	  OpenFirmware MTD accessors
+
 config OF_PCI
 	def_tristate PCI
 	depends on PCI
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index d7efd9d458aa..965c2a691337 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -8,6 +8,7 @@ obj-$(CONFIG_OF_IRQ)    += irq.o
 obj-$(CONFIG_OF_NET)	+= of_net.o
 obj-$(CONFIG_OF_UNITTEST) += unittest.o
 obj-$(CONFIG_OF_MDIO)	+= of_mdio.o
+obj-$(CONFIG_OF_MTD)	+= of_mtd.o
 obj-$(CONFIG_OF_PCI)	+= of_pci.o
 obj-$(CONFIG_OF_PCI_IRQ)  += of_pci_irq.o
 obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o
diff --git a/drivers/of/of_mtd.c b/drivers/of/of_mtd.c
new file mode 100644
index 000000000000..ff851d7742d5
--- /dev/null
+++ b/drivers/of/of_mtd.c
@@ -0,0 +1,30 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/of.h>
+#include <linux/of_mtd.h>
+
+const char * const *of_mtd_get_probes(struct device_node *np)
+{
+	const char **res;
+	int count;
+
+	count = of_property_count_strings(np, "linux,part-probe");
+	if (count < 0)
+		return NULL;
+
+	res = kzalloc((count + 1) * sizeof(*res), GFP_KERNEL);
+	if (!res)
+		return NULL;
+
+	count = of_property_read_string_array(np, "linux,part-probe", res,
+					      count);
+	if (count < 0)
+		return NULL;
+
+	return res;
+}
+EXPORT_SYMBOL(of_mtd_get_probes);
diff --git a/include/linux/of_mtd.h b/include/linux/of_mtd.h
new file mode 100644
index 000000000000..d55f4aa684c5
--- /dev/null
+++ b/include/linux/of_mtd.h
@@ -0,0 +1,25 @@
+#ifndef __OF_MTD_H
+#define __OF_MTD_H
+
+#include <linux/slab.h>
+
+struct device_node;
+
+#ifdef CONFIG_OF_MTD
+const char * const *of_mtd_get_probes(struct device_node *np);
+static inline void of_mtd_free_probes(const char * const *probes)
+{
+	kfree(probes);
+}
+#else
+const char * const *of_mtd_get_probes(struct device_node *np)
+{
+	return NULL;
+}
+
+static inline void of_mtd_free_probes(const char * const *probes)
+{
+}
+#endif
+
+#endif
-- 
2.11.0