OMAP: mux: Add support for control module split in several partitions

Starting on OMAP4, the pin mux configuration is located in two
different partitions of the control module (CODE_PAD and WKUP_PAD).
The first one is inside the core power domain whereas the second
one is inside the wakeup.
- Add the capability to add any number of partition during board init
time depending of Soc partitioning.
- Add some init flags as well in order to avoid explicit Soc version
check inside the mux core code.
- Add a comment with mux0 mode on top of omap_mux/board/<partition>
if the current mux mode is not the default one.

Thanks to Tony Lindgren <tony@atomide.com> for the following improvements:
- Add omap_mux_get for getting the partition data so platform level
device code can use it.
- Fix the rx51 board code to use the new API.
- Do not store the partition for each mux entry. Look up the partition
for debugfs instead.

Thanks to Dan Murphy <dmurphy@ti.com> for testing on OMAP4 and reporting
a couple of bugs.
Thanks to Anand Gadiyar <gadiyar@ti.com> for testing on OMAP3 zoom and
bug report.

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Murphy Dan <dmurphy@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Anand Gadiyar <gadiyar@ti.com>

arch/arm/mach-omap2/board-rx51-peripherals.c

@@ -293,16 +293,18 @@ static struct omap_board_mux rx51_mmc2_off_mux[] = {
 	{ .reg_offset = OMAP_MUX_TERMINATOR },
 };
 
+static struct omap_mux_partition *partition;
+
 /*
  * Current flows to eMMC when eMMC is off and the data lines are pulled up,
  * so pull them down. N.B. we pull 8 lines because we are using 8 lines.
  */
 static void rx51_mmc2_remux(struct device *dev, int slot, int power_on)
 {
 	if (power_on)
-		omap_mux_write_array(rx51_mmc2_on_mux);
+		omap_mux_write_array(partition, rx51_mmc2_on_mux);
 	else
-		omap_mux_write_array(rx51_mmc2_off_mux);
+		omap_mux_write_array(partition, rx51_mmc2_off_mux);
 }
 
 static struct omap2_hsmmc_info mmc[] __initdata = {
@@ -922,7 +924,11 @@ void __init rx51_peripherals_init(void)
 	rx51_init_wl1251();
 	spi_register_board_info(rx51_peripherals_spi_board_info,
 				ARRAY_SIZE(rx51_peripherals_spi_board_info));
-	omap2_hsmmc_init(mmc);
+
+	partition = omap_mux_get("core");
+	if (partition)
+		omap2_hsmmc_init(mmc);
+
 	platform_device_register(&rx51_charger_device);
 }