pmic:pfuze implement pmic_mode_init

This patch is to implement pmic_mode_init function, and add prototype
in header file.

This function is to set switching mode for pmic buck regulators to
improve system efficiency.

Mode:
OFF: The regulator is switched off and the output voltage is discharged.
PFM: In this mode, the regulator is always in PFM mode, which
     is useful at light loads for optimized efficiency.
PWM: In this mode, the regulator is always in PWM mode operation
     regardless of load conditions.
APS: In this mode, the regulator moves automatically between
     pulse skipping mode and PWM mode depending on load conditions.

Signed-off-by: Peng Fan <Peng.Fan@freescale.com>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

board/freescale/common/pfuze.c

@@ -5,9 +5,47 @@
  */
 
 #include <common.h>
+#include <errno.h>
 #include <power/pmic.h>
 #include <power/pfuze100_pmic.h>
 
+int pfuze_mode_init(struct pmic *p, u32 mode)
+{
+	unsigned char offset, i, switch_num;
+	u32 id, ret;
+
+	pmic_reg_read(p, PFUZE100_DEVICEID, &id);
+	id = id & 0xf;
+
+	if (id == 0) {
+		switch_num = 6;
+		offset = PFUZE100_SW1CMODE;
+	} else if (id == 1) {
+		switch_num = 4;
+		offset = PFUZE100_SW2MODE;
+	} else {
+		printf("Not supported, id=%d\n", id);
+		return -EINVAL;
+	}
+
+	ret = pmic_reg_write(p, PFUZE100_SW1ABMODE, mode);
+	if (ret < 0) {
+		printf("Set SW1AB mode error!\n");
+		return ret;
+	}
+
+	for (i = 0; i < switch_num - 1; i++) {
+		ret = pmic_reg_write(p, offset + i * SWITCH_SIZE, mode);
+		if (ret < 0) {
+			printf("Set switch 0x%x mode error!\n",
+			       offset + i * SWITCH_SIZE);
+			return ret;
+		}
+	}
+
+	return ret;
+}
+
 struct pmic *pfuze_common_init(unsigned char i2cbus)
 {
 	struct pmic *p;

board/freescale/common/pfuze.h

@@ -8,5 +8,6 @@
 #define __PFUZE_BOARD_HELPER__
 
 struct pmic *pfuze_common_init(unsigned char i2cbus);
+int pfuze_mode_init(struct pmic *p, u32 mode);
 
 #endif