lucid: add support to detect BC1.2 suppliers

Use built-in USB periperal to detect BC1.2 suppliers and update the
charge manager.

BUG=chrome-os-partner:48658
BRANCH=None
TEST=manual for lucid. Use a samus as the supplier, and insert the
charger into Lucid. Verify that it identifies it as SDP. Use a wall
charger and verify that Lucid identifies it as DCP.

Change-Id: I7842e9f75874f727837df5bfc28690662caf821c
Signed-off-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/329236
Reviewed-by: Shawn N <shawnn@chromium.org>

3 files changed, 65 insertions, 0 deletions

diff --git a/chip/stm32/build.mk b/chip/stm32/build.mk
index 53b48b6ab5..6878c76065 100644
--- a/chip/stm32/build.mk
+++ b/chip/stm32/build.mk
@@ -50,6 +50,7 @@ chip-$(CHIP_FAMILY_STM32F0)+=flash-f.o
 chip-$(CHIP_FAMILY_STM32F3)+=flash-f.o
 endif
 chip-$(CONFIG_ADC)+=adc-$(CHIP_FAMILY).o
+chip-$(CONFIG_STM32_CHARGER_DETECT)+=charger_detect.o
 chip-$(CONFIG_DEBUG_PRINTF)+=debug_printf.o
 chip-$(CONFIG_PWM)+=pwm.o
 chip-$(CONFIG_USB)+=usb.o usb-$(CHIP_FAMILY).o usb_endpoints.o
diff --git a/chip/stm32/charger_detect.c b/chip/stm32/charger_detect.c
new file mode 100644
index 0000000000..b32b9f3ac0
--- /dev/null
+++ b/chip/stm32/charger_detect.c
@@ -0,0 +1,55 @@
+/* Copyright 2016 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+/* Detect what adapter is connected */
+
+#include "charge_manager.h"
+#include "hooks.h"
+#include "registers.h"
+#include "timer.h"
+
+static void enable_usb(void)
+{
+	/* Enable USB device clock. */
+	STM32_RCC_APB1ENR |= STM32_RCC_PB1_USB;
+}
+DECLARE_HOOK(HOOK_INIT, enable_usb, HOOK_PRIO_DEFAULT);
+
+static void disable_usb(void)
+{
+	/* Disable USB device clock. */
+	STM32_RCC_APB1ENR &= ~STM32_RCC_PB1_USB;
+}
+DECLARE_HOOK(HOOK_SYSJUMP, disable_usb, HOOK_PRIO_DEFAULT);
+
+static uint16_t detect_type(uint16_t det_type)
+{
+	STM32_USB_BCDR &= 0;
+	usleep(1);
+	STM32_USB_BCDR |= (STM32_USB_BCDR_BCDEN | det_type);
+	usleep(1);
+	STM32_USB_BCDR &= ~(STM32_USB_BCDR_BCDEN | det_type);
+	return STM32_USB_BCDR;
+}
+
+
+int charger_detect_get_device_type(void)
+{
+	uint16_t pdet_result;
+
+	if (!(detect_type(STM32_USB_BCDR_DCDEN) & STM32_USB_BCDR_DCDET))
+		return CHARGE_SUPPLIER_PD;
+
+	pdet_result = detect_type(STM32_USB_BCDR_PDEN);
+	/* TODO: add support for detecting proprietary chargers. */
+	if (pdet_result & STM32_USB_BCDR_PDET) {
+		if (detect_type(STM32_USB_BCDR_SDEN) & STM32_USB_BCDR_SDET)
+			return CHARGE_SUPPLIER_BC12_DCP;
+		else
+			return CHARGE_SUPPLIER_BC12_CDP;
+	} else if (pdet_result & STM32_USB_BCDR_PS2DET)
+		return CHARGE_SUPPLIER_PROPRIETARY;
+	else
+		return CHARGE_SUPPLIER_BC12_SDP;
+}
diff --git a/chip/stm32/registers.h b/chip/stm32/registers.h
index 57fb2a9ec0..283fd44498 100644
--- a/chip/stm32/registers.h
+++ b/chip/stm32/registers.h
@@ -1327,6 +1327,15 @@ typedef volatile struct stm32_dma_regs stm32_dma_regs_t;
 #define STM32_USB_LPMCSR           REG16(STM32_USB_FS_BASE + 0x54)
 #define STM32_USB_BCDR             REG16(STM32_USB_FS_BASE + 0x58)
 
+#define STM32_USB_BCDR_BCDEN	    (1 << 0)
+#define STM32_USB_BCDR_DCDEN	    (1 << 1)
+#define STM32_USB_BCDR_PDEN	    (1 << 2)
+#define STM32_USB_BCDR_SDEN	    (1 << 3)
+#define STM32_USB_BCDR_DCDET	    (1 << 4)
+#define STM32_USB_BCDR_PDET	    (1 << 5)
+#define STM32_USB_BCDR_SDET	    (1 << 6)
+#define STM32_USB_BCDR_PS2DET	    (1 << 7)
+
 #define EP_MASK     0x0F0F
 #define EP_TX_DTOG  0x0040
 #define EP_TX_MASK  0x0030