USB: Add support for board specific connect/disconnect

Previously the usb driver used #ifs to select a mechanism to
enable and disable the DP pullup.  This doesn't scale well,
especially when the knowledge of how to do this is not known
to the chip specific code, but instead is board specific (as
it is with the STM32F373).

This change uses the build systems ability to build chip family
specific files per build to select the appropriate behavior.
And on the STM32F3 family of parts it just calls out to a board
specific pair of connect/disconnect functions.

Signed-off-by: Anton Staaf <robotboy@chromium.org>

BRANCH=None
BUG=None
TEST=make buildall -j
     Enable console on ryu_p2 and discovery-stm32f072 board
     Verify that it works on both

Change-Id: I976e02fbc7acbb0f85817d7295b26ee9ecab0711
Reviewed-on: https://chromium-review.googlesource.com/229040
Tested-by: Anton Staaf <robotboy@chromium.org>
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
Commit-Queue: Anton Staaf <robotboy@chromium.org>

6 files changed, 79 insertions, 32 deletions

diff --git a/chip/stm32/build.mk b/chip/stm32/build.mk
index 57b711f094..75f97fb7b2 100644
--- a/chip/stm32/build.mk
+++ b/chip/stm32/build.mk
@@ -45,7 +45,7 @@ chip-$(CHIP_FAMILY_STM32F0)+=flash-f.o
 chip-$(CHIP_FAMILY_STM32F3)+=flash-f.o
 chip-$(CONFIG_ADC)+=adc-$(CHIP_FAMILY).o
 chip-$(CONFIG_PWM)+=pwm.o
-chip-$(CONFIG_USB)+=usb.o usb_endpoints.o
+chip-$(CONFIG_USB)+=usb.o usb-$(CHIP_FAMILY).o usb_endpoints.o
 chip-$(CONFIG_USB_CONSOLE)+=usb_console.o
 chip-$(CONFIG_USB_GPIO)+=usb_gpio.o
 chip-$(CONFIG_USB_HID)+=usb_hid.o
diff --git a/chip/stm32/usb-stm32f0.c b/chip/stm32/usb-stm32f0.c
new file mode 100644
index 0000000000..1805c74e5e
--- /dev/null
+++ b/chip/stm32/usb-stm32f0.c
@@ -0,0 +1,20 @@
+/* Copyright (c) 2014 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.
+ *
+ * STM32F0 Family specific USB functionality
+ */
+
+#include "registers.h"
+#include "usb_api.h"
+
+void usb_connect(void)
+{
+	STM32_USB_BCDR |= (1 << 15) /* DPPU */;
+}
+
+void usb_disconnect(void)
+{
+	/* disable pull-up on DP to disconnect */
+	STM32_USB_BCDR &= ~(1 << 15) /* DPPU */;
+}
diff --git a/chip/stm32/usb-stm32f3.c b/chip/stm32/usb-stm32f3.c
new file mode 100644
index 0000000000..ceab410da0
--- /dev/null
+++ b/chip/stm32/usb-stm32f3.c
@@ -0,0 +1,20 @@
+/* Copyright (c) 2014 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.
+ *
+ * STM32F3 Family specific USB functionality
+ */
+
+#include "usb-stm32f3.h"
+
+#include "usb_api.h"
+
+void usb_connect(void)
+{
+	usb_board_connect();
+}
+
+void usb_disconnect(void)
+{
+	usb_board_connect();
+}
diff --git a/chip/stm32/usb-stm32f3.h b/chip/stm32/usb-stm32f3.h
new file mode 100644
index 0000000000..cf4590fa11
--- /dev/null
+++ b/chip/stm32/usb-stm32f3.h
@@ -0,0 +1,17 @@
+/* Copyright (c) 2014 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.
+ *
+ * STM32F3 Family specific USB functionality
+ */
+
+/*
+ * A device that uses an STM32F3 part will need to define these two functions
+ * which are used to connect and disconnect the device from the USB bus.  This
+ * is usually accomplished by enabling a pullup on the DP USB line.  The pullup
+ * should be enabled by default so that the STM32 will enumerate correctly in
+ * DFU mode (which doesn't know how to enable the DP pullup, so it assumes that
+ * the pullup is always there).
+ */
+void usb_board_connect(void);
+void usb_board_disconnect(void);
diff --git a/chip/stm32/usb-stm32l.c b/chip/stm32/usb-stm32l.c
new file mode 100644
index 0000000000..c5d58257cb
--- /dev/null
+++ b/chip/stm32/usb-stm32l.c
@@ -0,0 +1,20 @@
+/* Copyright (c) 2014 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.
+ *
+ * STM32L Family specific USB functionality
+ */
+
+#include "registers.h"
+#include "usb_api.h"
+
+void usb_connect(void)
+{
+	STM32_SYSCFG_PMC |= 1;
+}
+
+void usb_disconnect(void)
+{
+	/* disable pull-up on DP to disconnect */
+	STM32_SYSCFG_PMC &= ~1;
+}
diff --git a/chip/stm32/usb.c b/chip/stm32/usb.c
index 18193d4ffa..425b768632 100644
--- a/chip/stm32/usb.c
+++ b/chip/stm32/usb.c
@@ -303,40 +303,10 @@ void usb_init(void)
 }
 DECLARE_HOOK(HOOK_INIT, usb_init, HOOK_PRIO_DEFAULT);
 
-void usb_disconnect(void)
-{
-	/* disable pull-up on DP to disconnect */
-#ifdef CHIP_VARIANT_STM32L15X
-	STM32_SYSCFG_PMC &= ~1;
-#elif defined(CHIP_FAMILY_STM32F0)
-	STM32_USB_BCDR &= ~(1 << 15) /* DPPU */;
-#else
-#warn "usb disconnect not implemented for this chip family"
-#endif
-}
-
-void usb_connect(void)
-{
-	/* enable pull-up on DP to connect */
-#ifdef CHIP_VARIANT_STM32L15X
-	STM32_SYSCFG_PMC |= 1;
-#elif defined(CHIP_FAMILY_STM32F0)
-	STM32_USB_BCDR |= (1 << 15) /* DPPU */;
-#else
-#warn "usb connect not implemented for this chip family"
-#endif
-}
-
 void usb_release(void)
 {
 	/* signal disconnect to host */
-#ifdef CHIP_VARIANT_STM32L15X
-	STM32_SYSCFG_PMC &= ~1;
-#elif defined(CHIP_FAMILY_STM32F0)
-	STM32_USB_BCDR &= ~(1 << 15) /* DPPU */;
-#else
-	/* hardwired or regular GPIO on other platforms */
-#endif
+	usb_disconnect();
 
 	/* power down USB */
 	STM32_USB_CNTR = 0;