ARM: OMAP2+: Add device-tree support for NOR flash
NOR flash is not currently supported when booting with device-tree
on OMAP2+ devices. Add support to detect and configure NOR devices
when booting with device-tree.
Add documentation for the TI GPMC NOR binding.
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index ab658eb..c7bf6dd 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -26,6 +26,7 @@
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/of.h>
+#include <linux/of_address.h>
#include <linux/of_mtd.h>
#include <linux/of_device.h>
#include <linux/mtd/nand.h>
@@ -499,6 +500,37 @@
return r;
}
+/**
+ * gpmc_cs_remap - remaps a chip-select physical base address
+ * @cs: chip-select to remap
+ * @base: physical base address to re-map chip-select to
+ *
+ * Re-maps a chip-select to a new physical base address specified by
+ * "base". Returns 0 on success and appropriate negative error code
+ * on failure.
+ */
+static int gpmc_cs_remap(int cs, u32 base)
+{
+ int ret;
+ u32 old_base, size;
+
+ if (cs > GPMC_CS_NUM)
+ return -ENODEV;
+ gpmc_cs_get_memconf(cs, &old_base, &size);
+ if (base == old_base)
+ return 0;
+ gpmc_cs_disable_mem(cs);
+ ret = gpmc_cs_delete_mem(cs);
+ if (ret < 0)
+ return ret;
+ ret = gpmc_cs_insert_mem(cs, base, size);
+ if (ret < 0)
+ return ret;
+ gpmc_cs_enable_mem(cs, base, size);
+
+ return 0;
+}
+
int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
{
struct resource *res = &gpmc_cs_mem[cs];
@@ -1386,6 +1418,80 @@
}
#endif
+/**
+ * gpmc_probe_nor_child - configures the gpmc for a nor device
+ * @pdev: pointer to gpmc platform device
+ * @child: pointer to device-tree node for nor device
+ *
+ * Allocates and configures a GPMC chip-select for a NOR flash device.
+ * Returns 0 on success and appropriate negative error code on failure.
+ */
+static int gpmc_probe_nor_child(struct platform_device *pdev,
+ struct device_node *child)
+{
+ struct gpmc_settings gpmc_s;
+ struct gpmc_timings gpmc_t;
+ struct resource res;
+ unsigned long base;
+ int ret, cs;
+
+ if (of_property_read_u32(child, "reg", &cs) < 0) {
+ dev_err(&pdev->dev, "%s has no 'reg' property\n",
+ child->full_name);
+ return -ENODEV;
+ }
+
+ if (of_address_to_resource(child, 0, &res) < 0) {
+ dev_err(&pdev->dev, "%s has malformed 'reg' property\n",
+ child->full_name);
+ return -ENODEV;
+ }
+
+ ret = gpmc_cs_request(cs, resource_size(&res), &base);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "cannot request GPMC CS %d\n", cs);
+ return ret;
+ }
+
+ /*
+ * FIXME: gpmc_cs_request() will map the CS to an arbitary
+ * location in the gpmc address space. When booting with
+ * device-tree we want the NOR flash to be mapped to the
+ * location specified in the device-tree blob. So remap the
+ * CS to this location. Once DT migration is complete should
+ * just make gpmc_cs_request() map a specific address.
+ */
+ ret = gpmc_cs_remap(cs, res.start);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "cannot remap GPMC CS %d to 0x%x\n",
+ cs, res.start);
+ goto err;
+ }
+
+ gpmc_read_settings_dt(child, &gpmc_s);
+
+ ret = of_property_read_u32(child, "bank-width", &gpmc_s.device_width);
+ if (ret < 0)
+ goto err;
+
+ ret = gpmc_cs_program_settings(cs, &gpmc_s);
+ if (ret < 0)
+ goto err;
+
+ gpmc_read_timings_dt(child, &gpmc_t);
+ gpmc_cs_set_timings(cs, &gpmc_t);
+
+ if (of_platform_device_create(child, NULL, &pdev->dev))
+ return 0;
+
+ dev_err(&pdev->dev, "failed to create gpmc child %s\n", child->name);
+
+err:
+ gpmc_cs_free(cs);
+
+ return ret;
+}
+
static int gpmc_probe_dt(struct platform_device *pdev)
{
int ret;
@@ -1418,6 +1524,15 @@
return ret;
}
}
+
+ for_each_node_by_name(child, "nor") {
+ ret = gpmc_probe_nor_child(pdev, child);
+ if (ret < 0) {
+ of_node_put(child);
+ return ret;
+ }
+ }
+
return 0;
}
#else