regmap-mmio: Use native endianness for read/write

The regmap API has an endianness setting for formatting reads and writes.
This can be set by the usual DT "little-endian" and "big-endian" properties.
To work properly the associated regmap_bus needs to read/write in native
endian.

The "syscon" DT device binding creates an mmio-based regmap_bus which
performs all reads/writes as little-endian. These values are then converted
again by regmap, which means that all of the MIPS BCM boards (which are
big-endian) have been declared as "little-endian" to get regmap to convert
them back to big-endian.

Modify regmap-mmio to use the native-endian functions __raw_read*() and
__raw_write*() instead of the little-endian functions read*() and
write*().

Modify the big-endian MIPS BCM boards to use what will now be the correct
endianness instead of pretending that the devices are little-endian.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Mark Brown <broonie@kernel.org>

arch/mips/boot/dts/brcm/bcm6328.dtsi

@@ -73,7 +73,6 @@ uart0: serial@10000100 {
 		timer: timer@10000040 {
 			compatible = "syscon";
 			reg = <0x10000040 0x2c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7125.dtsi

@@ -98,7 +98,6 @@ upg_irq0_intc: upg_irq0_intc@406780 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7125-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x60c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7346.dtsi

@@ -118,7 +118,6 @@ upg_aon_irq0_intc: upg_aon_irq0_intc@408b80 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7346-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x51c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7358.dtsi

@@ -112,7 +112,6 @@ upg_aon_irq0_intc: upg_aon_irq0_intc@408b80 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7358-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x51c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7360.dtsi

@@ -112,7 +112,6 @@ upg_aon_irq0_intc: upg_aon_irq0_intc@408b80 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7360-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x51c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7362.dtsi

@@ -118,7 +118,6 @@ upg_aon_irq0_intc: upg_aon_irq0_intc@408b80 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7362-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x51c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7420.dtsi

@@ -99,7 +99,6 @@ upg_irq0_intc: upg_irq0_intc@406780 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7420-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x60c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7425.dtsi

@@ -100,7 +100,6 @@ upg_irq0_intc: upg_irq0_intc@406780 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7425-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x51c>;
-			little-endian;
 		};
 
 		reboot {

arch/mips/boot/dts/brcm/bcm7435.dtsi

@@ -114,7 +114,6 @@ upg_irq0_intc: upg_irq0_intc@406780 {
 		sun_top_ctrl: syscon@404000 {
 			compatible = "brcm,bcm7425-sun-top-ctrl", "syscon";
 			reg = <0x404000 0x51c>;
-			little-endian;
 		};
 
 		reboot {

drivers/base/regmap/regmap-mmio.c

@@ -106,17 +106,17 @@ static int regmap_mmio_gather_write(void *context,
 	while (val_size) {
 		switch (ctx->val_bytes) {
 		case 1:
-			writeb(*(u8 *)val, ctx->regs + offset);
+			__raw_writeb(*(u8 *)val, ctx->regs + offset);
 			break;
 		case 2:
-			writew(*(u16 *)val, ctx->regs + offset);
+			__raw_writew(*(u16 *)val, ctx->regs + offset);
 			break;
 		case 4:
-			writel(*(u32 *)val, ctx->regs + offset);
+			__raw_writel(*(u32 *)val, ctx->regs + offset);
 			break;
 #ifdef CONFIG_64BIT
 		case 8:
-			writeq(*(u64 *)val, ctx->regs + offset);
+			__raw_writeq(*(u64 *)val, ctx->regs + offset);
 			break;
 #endif
 		default:
@@ -166,17 +166,17 @@ static int regmap_mmio_read(void *context,
 	while (val_size) {
 		switch (ctx->val_bytes) {
 		case 1:
-			*(u8 *)val = readb(ctx->regs + offset);
+			*(u8 *)val = __raw_readb(ctx->regs + offset);
 			break;
 		case 2:
-			*(u16 *)val = readw(ctx->regs + offset);
+			*(u16 *)val = __raw_readw(ctx->regs + offset);
 			break;
 		case 4:
-			*(u32 *)val = readl(ctx->regs + offset);
+			*(u32 *)val = __raw_readl(ctx->regs + offset);
 			break;
 #ifdef CONFIG_64BIT
 		case 8:
-			*(u64 *)val = readq(ctx->regs + offset);
+			*(u64 *)val = __raw_readq(ctx->regs + offset);
 			break;
 #endif
 		default: