oak: enable HW charge ramping

refer to commit 75f740fa, enabling the option on oak too.

BUG=none
BRANCH=none
TEST=plug in CDP, SDP, DCP, type-C, and PD charger. Make sure
we ramp to a reasonable value for the correct suppliers.
Make sure we don't ramp for type-C and PD chargers.

Signed-off-by: Ben Lok <ben.lok@mediatek.com>
Change-Id: I9c6a0726e9cb23af59d5841c63a81897ae624998
Reviewed-on: https://chromium-review.googlesource.com/314436
Reviewed-by: Alec Berg <alecaberg@chromium.org>

board/oak/board.c

@@ -290,6 +290,40 @@ void board_set_charge_limit(int charge_ma)
 					   CONFIG_CHARGER_INPUT_CURRENT));
 }
 
+/**
+ * Return whether ramping is allowed for given supplier
+ */
+int board_is_ramp_allowed(int supplier)
+{
+	/* Don't allow ramping in RO when write protected */
+	if (system_get_image_copy() != SYSTEM_IMAGE_RW
+	    && system_is_locked())
+		return 0;
+	else
+		return supplier == CHARGE_SUPPLIER_BC12_DCP ||
+		       supplier == CHARGE_SUPPLIER_BC12_SDP ||
+		       supplier == CHARGE_SUPPLIER_BC12_CDP ||
+		       supplier == CHARGE_SUPPLIER_PROPRIETARY;
+}
+
+/**
+ * Return the maximum allowed input current
+ */
+int board_get_ramp_current_limit(int supplier, int sup_curr)
+{
+	switch (supplier) {
+	case CHARGE_SUPPLIER_BC12_DCP:
+		return 2000;
+	case CHARGE_SUPPLIER_BC12_SDP:
+		return 1000;
+	case CHARGE_SUPPLIER_BC12_CDP:
+	case CHARGE_SUPPLIER_PROPRIETARY:
+		return sup_curr;
+	default:
+		return 500;
+	}
+}
+
 static void hpd_irq_deferred(void)
 {
 	gpio_set_level(GPIO_USB_DP_HPD, 1);

board/oak/board.h

@@ -18,6 +18,7 @@
 #define CONFIG_BATTERY_PRESENT_GPIO GPIO_BAT_PRESENT_L
 #define CONFIG_BATTERY_SMART
 #define CONFIG_CHARGE_MANAGER
+#define CONFIG_CHARGE_RAMP_HW
 #define CONFIG_CHARGER
 
 #define CONFIG_CHARGER_INPUT_CURRENT 512