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@xxxxxx>
---
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
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