[PATCH 10/14] ARM: OMAP2+: Add function to read GPMC settings from device-tree

[Jon Hunter]

Adds a function to read the various GPMC chip-select settings from
device-tree and store them in the gpmc_settings structure.

Update the GPMC device-tree binding documentation to describe these
options.

Signed-off-by: Jon Hunter <jon-hunter at ti.com>
---
 Documentation/devicetree/bindings/bus/ti-gpmc.txt |   19 ++++++++
 arch/arm/mach-omap2/gpmc.c                        |   50 +++++++++++++++++++++
 arch/arm/mach-omap2/gpmc.h                        |    2 +
 3 files changed, 71 insertions(+)

diff --git a/Documentation/devicetree/bindings/bus/ti-gpmc.txt b/Documentation/devicetree/bindings/bus/ti-gpmc.txt
index 5ddb2e9..a31c32a 100644
--- a/Documentation/devicetree/bindings/bus/ti-gpmc.txt
+++ b/Documentation/devicetree/bindings/bus/ti-gpmc.txt
@@ -65,6 +65,25 @@ The following are only applicable to OMAP3+ and AM335x:
  - gpmc,wr-access
  - gpmc,wr-data-mux-bus
 
+GPMC chip-select settings properties for child nodes. All are optional.
+
+- gpmc,burst-length	Page/burst length. Must be 4, 8 or 16.
+- gpmc,burst-wrap	Enables wrap bursting
+- gpmc,burst-read	Enables read page/burst mode
+- gpmc,burst-write	Enables write page/burst mode
+- gpmc,device-nand	Device is NAND
+- gpmc,device-width	Width of device connected to the GPMC in bytes. The
+			GPMC supports 8-bit and 16-bit devices and so this
+			property must be 1 or 2.
+- gpmc,mux-add-data	Enables address and data multiplexing
+- gpmc,sync-read	Enables synchronous read. Defaults to asynchronous
+			is this is not set.
+- gpmc,sync-write	Enables synchronous writes. Defaults to asynchronous
+			is this is not set.
+- gpmc,wait-pin		Wait-pin used by client. Must be less than
+			"gpmc,num-waitpins".
+- gpmc,wait-on-read	Enables wait monitoring on reads.
+- gpmc,wait-on-write	Enables wait monitoring on writes.
 
 Example for an AM33xx board:
 
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index 7cf3d98..e822d2b 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -1182,6 +1182,56 @@ static struct of_device_id gpmc_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, gpmc_dt_ids);
 
+/**
+ * gpmc_read_settings_dt - read gpmc settings from device-tree
+ * @np:		pointer to device-tree node for a gpmc child device
+ * @p:		pointer to gpmc settings structure
+ *
+ * Reads the GPMC settings for a GPMC child device from device-tree and
+ * stores them in the GPMC settings structure passed. The GPMC settings
+ * structure is initialise to zero by this function and so any previously
+ * stored settings will be clearer.
+ */
+void gpmc_read_settings_dt(struct device_node *np, struct gpmc_settings *p)
+{
+	memset(p, 0, sizeof(struct gpmc_settings));
+
+	if (of_find_property(np, "gpmc,sync-read", NULL))
+		p->sync_read = true;
+	if (of_find_property(np, "gpmc,sync-write", NULL))
+		p->sync_write = true;
+
+	if (!of_property_read_u32(np, "gpmc,burst-length", &p->burst_len)) {
+		if (of_find_property(np, "gpmc,burst-wrap", NULL))
+			p->burst_wrap = true;
+		if (of_find_property(np, "gpmc,burst-read", NULL))
+			p->burst_read = true;
+		if (of_find_property(np, "gpmc,burst-write", NULL))
+			p->burst_write = true;
+		if (!p->burst_read && !p->burst_write)
+			pr_warn("%s: page/burst-length set but not used!\n",
+				__func__);
+	}
+
+	if (!of_property_read_u32(np, "gpmc,wait-pin", &p->wait_pin)) {
+		if (of_find_property(np, "gpmc,wait-on-read", NULL))
+			p->wait_on_read = true;
+		if (of_find_property(np, "gpmc,wait-on-write", NULL))
+			p->wait_on_write = true;
+		if (!p->wait_on_read && !p->wait_on_write)
+			pr_warn("%s: read/write wait monitoring not enabled!\n",
+				__func__);
+	}
+
+	of_property_read_u32(np, "gpmc,device-width", &p->device_width);
+
+	if (of_find_property(np, "gpmc,device-nand", NULL))
+		p->device_nand = true;
+
+	if (of_find_property(np, "gpmc,mux-add-data", NULL))
+		p->mux_add_data = true;
+}
+
 static void __maybe_unused gpmc_read_timings_dt(struct device_node *np,
 						struct gpmc_timings *gpmc_t)
 {
diff --git a/arch/arm/mach-omap2/gpmc.h b/arch/arm/mach-omap2/gpmc.h
index d73fda0..c517eaa 100644
--- a/arch/arm/mach-omap2/gpmc.h
+++ b/arch/arm/mach-omap2/gpmc.h
@@ -230,5 +230,7 @@ extern int gpmc_cs_reserved(int cs);
 extern void omap3_gpmc_save_context(void);
 extern void omap3_gpmc_restore_context(void);
 extern int gpmc_configure(int cmd, int wval);
+extern void gpmc_read_settings_dt(struct device_node *np,
+				  struct gpmc_settings *p);
 
 #endif
-- 
1.7.10.4