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authorTimur Tabi <timur@freescale.com>2012-02-16 04:25:47 +0400
committerKumar Gala <galak@kernel.crashing.org>2012-03-16 19:46:33 +0400
commit4951896aad0b73a8163eb23d44818993237bc0cf (patch)
tree0e30431ff99cf89620b1bb5864ccd6823a3d400b
parent4a170d0198330b8615778f6f0e265cdaadfd54b4 (diff)
downloadlinux-4951896aad0b73a8163eb23d44818993237bc0cf.tar.xz
powerpc/85xx: p1022ds: disable the NOR flash node if video is enabled
The Freescale P1022 has a unique pin muxing "feature" where the DIU video controller's video signals are muxed with 24 of the local bus address signals. When the DIU is enabled, the bulk of the local bus is disabled, preventing access to memory-mapped devices like NOR flash and the pixis FPGA. Therefore, if the DIU is going to be enabled, then memory-mapped devices on the localbus, like NOR flash, need to be disabled. This also means that the localbus is not a 'simple-bus' any more, so remove that string from the compatible node. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
-rw-r--r--arch/powerpc/boot/dts/fsl/p1022si-post.dtsi6
-rw-r--r--arch/powerpc/platforms/85xx/p1022_ds.c71
2 files changed, 76 insertions, 1 deletions
diff --git a/arch/powerpc/boot/dts/fsl/p1022si-post.dtsi b/arch/powerpc/boot/dts/fsl/p1022si-post.dtsi
index de4521531f62..06216b8c0af5 100644
--- a/arch/powerpc/boot/dts/fsl/p1022si-post.dtsi
+++ b/arch/powerpc/boot/dts/fsl/p1022si-post.dtsi
@@ -35,7 +35,11 @@
&lbc {
#address-cells = <2>;
#size-cells = <1>;
- compatible = "fsl,p1022-elbc", "fsl,elbc", "simple-bus";
+ /*
+ * The localbus on the P1022 is not a simple-bus because of the eLBC
+ * pin muxing when the DIU is enabled.
+ */
+ compatible = "fsl,p1022-elbc", "fsl,elbc";
interrupts = <19 2 0 0>;
};
diff --git a/arch/powerpc/platforms/85xx/p1022_ds.c b/arch/powerpc/platforms/85xx/p1022_ds.c
index 63ba79053960..e211b0d756f0 100644
--- a/arch/powerpc/platforms/85xx/p1022_ds.c
+++ b/arch/powerpc/platforms/85xx/p1022_ds.c
@@ -249,6 +249,49 @@ void __init p1022_ds_pic_init(void)
mpic_init(mpic);
}
+#if defined(CONFIG_FB_FSL_DIU) || defined(CONFIG_FB_FSL_DIU_MODULE)
+
+/*
+ * Disables a node in the device tree.
+ *
+ * This function is called before kmalloc() is available, so the 'new' object
+ * should be allocated in the global area. The easiest way is to do that is
+ * to allocate one static local variable for each call to this function.
+ */
+static void __init disable_one_node(struct device_node *np, struct property *new)
+{
+ struct property *old;
+
+ old = of_find_property(np, new->name, NULL);
+ if (old)
+ prom_update_property(np, new, old);
+ else
+ prom_add_property(np, new);
+}
+
+/* TRUE if there is a "video=fslfb" command-line parameter. */
+static bool fslfb;
+
+/*
+ * Search for a "video=fslfb" command-line parameter, and set 'fslfb' to
+ * true if we find it.
+ *
+ * We need to use early_param() instead of __setup() because the normal
+ * __setup() gets called to late. However, early_param() gets called very
+ * early, before the device tree is unflattened, so all we can do now is set a
+ * global variable. Later on, p1022_ds_setup_arch() will use that variable
+ * to determine if we need to update the device tree.
+ */
+static int __init early_video_setup(char *options)
+{
+ fslfb = (strncmp(options, "fslfb:", 6) == 0);
+
+ return 0;
+}
+early_param("video", early_video_setup);
+
+#endif
+
/*
* Setup the architecture
*/
@@ -286,6 +329,34 @@ static void __init p1022_ds_setup_arch(void)
diu_ops.set_monitor_port = p1022ds_set_monitor_port;
diu_ops.set_pixel_clock = p1022ds_set_pixel_clock;
diu_ops.valid_monitor_port = p1022ds_valid_monitor_port;
+
+ /*
+ * Disable the NOR flash node if there is video=fslfb... command-line
+ * parameter. When the DIU is active, NOR flash is unavailable, so we
+ * have to disable the node before the MTD driver loads.
+ */
+ if (fslfb) {
+ struct device_node *np =
+ of_find_compatible_node(NULL, NULL, "fsl,p1022-elbc");
+
+ if (np) {
+ np = of_find_compatible_node(np, NULL, "cfi-flash");
+ if (np) {
+ static struct property nor_status = {
+ .name = "status",
+ .value = "disabled",
+ .length = sizeof("disabled"),
+ };
+
+ pr_info("p1022ds: disabling %s node",
+ np->full_name);
+ disable_one_node(np, &nor_status);
+ of_node_put(np);
+ }
+ }
+
+ }
+
#endif
mpc85xx_smp_init();