OMAP3: control/PM: move padconf save code to mach-omap2/control.c

Move the padconf save code from pm34xx.c to the System Control Module
code in mach-omap2/control.c.  This is part of the general push to
move direct register access from middle-layer core code to low-level
core code, so the middle-layer code can be abstracted to work on
multiple platforms and cleaned up.

In the medium-to-long term, this code should be called by the mux
layer code, not the PM idle code.  This is because, according to the
TRM, saving the padconf only needs to be done when the padconf
changes[1].

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Tony Lindgren <tony@atomide.com>
Tested-by: Rajendra Nayak <rnayak@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>

1. OMAP34xx Multimedia Device Silicon Revision 3.1.x [Rev. ZH] [SWPU222H]
   Section 4.11.4 "Device Off-Mode Sequences"

1 files changed, 31 insertions, 0 deletions

diff --git a/arch/arm/mach-omap2/control.c b/arch/arm/mach-omap2/control.c
index 61101e8..6952794 100644
--- a/arch/arm/mach-omap2/control.c
+++ b/arch/arm/mach-omap2/control.c
@@ -26,6 +26,10 @@
 #include "pm.h"
 #include "control.h"
 
+/* Used by omap3_ctrl_save_padconf() */
+#define START_PADCONF_SAVE		0x2
+#define PADCONF_SAVE_DONE		0x1
+
 static void __iomem *omap2_ctrl_base;
 static void __iomem *omap4_ctrl_pad_base;
 
@@ -530,4 +534,31 @@ void omap3630_ctrl_disable_rta(void)
 	omap_ctrl_writel(OMAP36XX_RTA_DISABLE, OMAP36XX_CONTROL_MEM_RTA_CTRL);
 }
 
+/**
+ * omap3_ctrl_save_padconf - save padconf registers to scratchpad RAM
+ *
+ * Tell the SCM to start saving the padconf registers, then wait for
+ * the process to complete.  Returns 0 unconditionally, although it
+ * should also eventually be able to return -ETIMEDOUT, if the save
+ * does not complete.
+ *
+ * XXX This function is missing a timeout.  What should it be?
+ */
+int omap3_ctrl_save_padconf(void)
+{
+	u32 cpo;
+
+	/* Save the padconf registers */
+	cpo = omap_ctrl_readl(OMAP343X_CONTROL_PADCONF_OFF);
+	cpo |= START_PADCONF_SAVE;
+	omap_ctrl_writel(cpo, OMAP343X_CONTROL_PADCONF_OFF);
+
+	/* wait for the save to complete */
+	while (!(omap_ctrl_readl(OMAP343X_CONTROL_GENERAL_PURPOSE_STATUS)
+		 & PADCONF_SAVE_DONE))
+		udelay(1);
+
+	return 0;
+}
+
 #endif /* CONFIG_ARCH_OMAP3 && CONFIG_PM */