discovery-stm32f072: Enable SPI over USB tunnel

Enable master control of SPI2 over USB for testing flashrom's
ability to write to a SPI flash chip attached to the stm32.

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

BRANCH=None
BUG=None
TEST=make buildall -j; write image using flashrom

Change-Id: I7d320acd28a03e91fcd7f7d697be40f69ea7bbdc
Reviewed-on: https://chromium-review.googlesource.com/218741
Reviewed-by: Vic Yang <victoryang@chromium.org>
Commit-Queue: Anton Staaf <robotboy@chromium.org>
Tested-by: Anton Staaf <robotboy@chromium.org>

6 files changed, 81 insertions, 19 deletions

diff --git a/board/discovery-stm32f072/board.h b/board/discovery-stm32f072/board.h
index 1e7d86363e..bb3fdee002 100644
--- a/board/discovery-stm32f072/board.h
+++ b/board/discovery-stm32f072/board.h
@@ -26,15 +26,36 @@
 /* Optional features */
 #define CONFIG_STM_HWTIMER32
 #define CONFIG_HW_CRC
+
+/* USB Configuration */
 #define CONFIG_USB
+#define CONFIG_USB_PID 0x500f
+
+/* USB interface indexes (use define rather than enum to expand them) */
+#define USB_IFACE_STREAM 0
+#define USB_IFACE_GPIO   1
+#define USB_IFACE_SPI    2
+#define USB_IFACE_COUNT  3
+
+/* USB endpoint indexes (use define rather than enum to expand them) */
+#define USB_EP_CONTROL 0
+#define USB_EP_STREAM  1
+#define USB_EP_GPIO    2
+#define USB_EP_SPI     3
+#define USB_EP_COUNT   4
+
+/* Enable control of GPIOs over USB */
 #define CONFIG_USB_GPIO
 
+/* Enable control of SPI over USB */
+#define CONFIG_SPI_MASTER_PORT 2
+#define CONFIG_SPI_CS_GPIO     GPIO_SPI_CS
+
+#define CONFIG_USB_SPI
+
 #undef CONFIG_WATCHDOG_HELP
 #undef CONFIG_LID_SWITCH
 
-/* USB configuration */
-#define CONFIG_USB_PID 0x500f
-
 /*
  * Allow dangerous commands all the time, since we don't have a write protect
  * switch.
@@ -59,16 +80,4 @@ enum usb_strings {
 };
 
 #endif /* !__ASSEMBLER__ */
-
-/* USB interface indexes (use define rather than enum to expand them) */
-#define USB_IFACE_STREAM	0
-#define USB_IFACE_GPIO		1
-#define USB_IFACE_COUNT		2
-
-/* USB endpoint indexes (use define rather than enum to expand them) */
-#define USB_EP_CONTROL		0
-#define USB_EP_STREAM		1
-#define USB_EP_GPIO		2
-#define USB_EP_COUNT		3
-
 #endif /* __BOARD_H */
diff --git a/board/discovery-stm32f072/build.mk b/board/discovery-stm32f072/build.mk
index d8a22a6ad5..7a40d5fc10 100644
--- a/board/discovery-stm32f072/build.mk
+++ b/board/discovery-stm32f072/build.mk
@@ -10,4 +10,4 @@ CHIP:=stm32
 CHIP_FAMILY:=stm32f0
 CHIP_VARIANT:=stm32f07x
 
-board-y=board.o echo.o
+board-y=board.o echo.o spi.o
diff --git a/board/discovery-stm32f072/ec.tasklist b/board/discovery-stm32f072/ec.tasklist
index ae6b6c06e7..73f7aa6835 100644
--- a/board/discovery-stm32f072/ec.tasklist
+++ b/board/discovery-stm32f072/ec.tasklist
@@ -17,6 +17,7 @@
  * 's' is the stack size in bytes; must be a multiple of 8
  */
 #define CONFIG_TASK_LIST \
-	TASK_ALWAYS(HOOKS, hook_task, NULL, TASK_STACK_SIZE) \
-	TASK_ALWAYS(CONSOLE, console_task, NULL, TASK_STACK_SIZE)\
-	TASK_ALWAYS(ECHO, echo_task, NULL, TASK_STACK_SIZE)
+	TASK_ALWAYS(HOOKS,   hook_task,    NULL, TASK_STACK_SIZE) \
+	TASK_ALWAYS(CONSOLE, console_task, NULL, TASK_STACK_SIZE) \
+	TASK_ALWAYS(USB_SPI, usb_spi_task, NULL, TASK_STACK_SIZE) \
+	TASK_ALWAYS(ECHO,    echo_task,    NULL, TASK_STACK_SIZE)
diff --git a/board/discovery-stm32f072/gpio.inc b/board/discovery-stm32f072/gpio.inc
index 0d7586f5ae..8c368c20b1 100644
--- a/board/discovery-stm32f072/gpio.inc
+++ b/board/discovery-stm32f072/gpio.inc
@@ -14,6 +14,13 @@ GPIO(LED_D, C, 7, GPIO_OUT_LOW, NULL)
 GPIO(LED_L, C, 8, GPIO_OUT_LOW, NULL)
 GPIO(LED_R, C, 9, GPIO_OUT_LOW, NULL)
 
+/* Flash SPI interface */
+GPIO(SPI_WP,   C,  3, GPIO_OUT_HIGH, NULL)
+GPIO(SPI_HOLD, C,  4, GPIO_OUT_HIGH, NULL)
+GPIO(SPI_CS,   B, 12, GPIO_OUT_HIGH, NULL)
+
+ALTERNATE(B, 0xE000, 0, MODULE_SPI_MASTER, 0)
+
 /* Unimplemented signals which we need to emulate for now */
 UNIMPLEMENTED(ENTERING_RW)
 UNIMPLEMENTED(WP_L)
diff --git a/board/discovery-stm32f072/spi.c b/board/discovery-stm32f072/spi.c
new file mode 100644
index 0000000000..225592f20a
--- /dev/null
+++ b/board/discovery-stm32f072/spi.c
@@ -0,0 +1,44 @@
+/* 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.
+ */
+#include "common.h"
+#include "gpio.h"
+#include "registers.h"
+#include "spi.h"
+#include "task.h"
+#include "usb_spi.h"
+
+void usb_spi_ready(struct usb_spi_config const *config)
+{
+	task_wake(TASK_ID_USB_SPI);
+}
+
+USB_SPI_CONFIG(usb_spi, USB_IFACE_SPI, USB_EP_SPI, usb_spi_ready)
+
+void usb_spi_task(void)
+{
+	/* Remap SPI2 to DMA channels 6 and 7 */
+	STM32_SYSCFG_CFGR1 |= (1 << 24);
+
+	gpio_config_module(MODULE_SPI_MASTER, 1);
+
+	/* Set all four SPI pins to high speed */
+	STM32_GPIO_OSPEEDR(GPIO_B) |= 0xff000000;
+
+	/* Enable clocks to SPI2 module */
+	STM32_RCC_APB1ENR |= STM32_RCC_PB1_SPI2;
+
+	/* Reset SPI2 */
+	STM32_RCC_APB1RSTR |= STM32_RCC_PB1_SPI2;
+	STM32_RCC_APB1RSTR &= ~STM32_RCC_PB1_SPI2;
+
+	spi_enable(1);
+
+	while (1) {
+		task_wait_event(-1);
+
+		while (usb_spi_service_request(&usb_spi))
+			;
+	}
+}
diff --git a/include/module_id.h b/include/module_id.h
index 55b05be8b3..9708e6ce90 100644
--- a/include/module_id.h
+++ b/include/module_id.h
@@ -35,6 +35,7 @@ enum module_id {
 	MODULE_PWM_KBLIGHT,
 	MODULE_PWM_LED,
 	MODULE_SPI,
+	MODULE_SPI_MASTER,
 	MODULE_SWITCH,
 	MODULE_SYSTEM,
 	MODULE_TASK,