discovery-stm32f072: Blink the LEDs

This just makes the LEDs blink continually, because I have a
development board sitting on my desk and I like to see it doing
something.

You can still force the GPIOs on and off using the tool in
extra/usb_gpio/.

BUG=none
BRANCH=none
TEST=make buildall

Try it:

  sudo make BOARD=discovery-stm32f072 flash

The LEDs blink.

Force them on and off with:

  cd extra/usb_gpio
  make
  ./usb_gpio write -1 0
  ./usb_gpio write 0 -1
  ./usb_gpio write 2 0
  ./usb_gpio write 4 2

To resume blinking, use

  ./usb_gpio write 0 0

Change-Id: Iadbe7436c02de5b6eae81885d95bad154ca3692c
Signed-off-by: Bill Richardson <wfrichar@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/274131
Reviewed-by: Anton Staaf <robotboy@chromium.org>

4 files changed, 30 insertions, 5 deletions

diff --git a/board/discovery-stm32f072/board.c b/board/discovery-stm32f072/board.c
index c6a9b3c8a3..8303aa6a27 100644
--- a/board/discovery-stm32f072/board.c
+++ b/board/discovery-stm32f072/board.c
@@ -39,10 +39,22 @@ static enum gpio_signal const usb_gpio_list[] = {
 	GPIO_LED_R,
 };
 
+/*
+ * This instantiates struct usb_gpio_config const usb_gpio, plus several other
+ * variables, all named something beginning with usb_gpio_
+ */
 USB_GPIO_CONFIG(usb_gpio,
 		usb_gpio_list,
 		USB_IFACE_GPIO,
-		USB_EP_GPIO)
+		USB_EP_GPIO);
+
+void usb_gpio_tick(void)
+{
+	if (usb_gpio.state->set_mask || usb_gpio.state->clear_mask)
+		return;
+	button_event(0);
+}
+DECLARE_HOOK(HOOK_TICK, usb_gpio_tick, HOOK_PRIO_DEFAULT);
 
 const void *const usb_strings[] = {
 	[USB_STR_DESC]         = usb_string_desc,
diff --git a/chip/stm32/usb_gpio.c b/chip/stm32/usb_gpio.c
index 027ddadaae..43cda832a8 100644
--- a/chip/stm32/usb_gpio.c
+++ b/chip/stm32/usb_gpio.c
@@ -39,6 +39,9 @@ void usb_gpio_rx(struct usb_gpio_config const *config)
 			        (uint32_t)(config->rx_ram[3]) << 16);
 	uint32_t ignore_mask = set_mask & clear_mask;
 
+	config->state->set_mask = set_mask;
+	config->state->clear_mask = clear_mask;
+
 	if ((btable_ep[config->endpoint].rx_count & 0x3ff) ==
 	    USB_GPIO_RX_PACKET_SIZE) {
 		for (i = 0; i < config->num_gpios; ++i, mask <<= 1) {
diff --git a/chip/stm32/usb_gpio.h b/chip/stm32/usb_gpio.h
index 2027df9d21..56f3d72c57 100644
--- a/chip/stm32/usb_gpio.h
+++ b/chip/stm32/usb_gpio.h
@@ -10,12 +10,19 @@
 #include "compile_time_macros.h"
 #include "usb.h"
 
+struct usb_gpio_state {
+	uint32_t set_mask;
+	uint32_t clear_mask;
+};
+
 /*
  * Compile time Per-USB gpio configuration stored in flash.  Instances of this
  * structure are provided by the user of the USB gpio.  This structure binds
  * together all information required to operate a USB gpio.
  */
 struct usb_gpio_config {
+	struct usb_gpio_state *state;
+
 	/*
 	 * Endpoint index, and pointers to the USB packet RAM buffers.
 	 */
@@ -55,6 +62,7 @@ struct usb_gpio_config {
 	static usb_uint CONCAT2(NAME, _ep_rx_buffer)[USB_GPIO_RX_PACKET_SIZE / 2] __usb_ram;	\
 	static usb_uint CONCAT2(NAME, _ep_tx_buffer)[USB_GPIO_TX_PACKET_SIZE / 2] __usb_ram;	\
 	struct usb_gpio_config const NAME = {				\
+		.state     = &((struct usb_gpio_state){}),		\
 		.endpoint  = ENDPOINT,					\
 		.rx_ram    = CONCAT2(NAME, _ep_rx_buffer),		\
 		.tx_ram    = CONCAT2(NAME, _ep_tx_buffer),		\
@@ -106,7 +114,8 @@ struct usb_gpio_config {
 	USB_DECLARE_EP(ENDPOINT,					\
 		       CONCAT2(NAME, _ep_tx),				\
 		       CONCAT2(NAME, _ep_rx),				\
-		       CONCAT2(NAME, _ep_reset));
+		       CONCAT2(NAME, _ep_reset))
+
 
 /*
  * These functions are used by the trampoline functions defined above to
diff --git a/extra/usb_gpio/usb_gpio.c b/extra/usb_gpio/usb_gpio.c
index 6c6d464963..70cf4a81c2 100644
--- a/extra/usb_gpio/usb_gpio.c
+++ b/extra/usb_gpio/usb_gpio.c
@@ -109,8 +109,9 @@ int main(int argc, char **argv)
 {
 	libusb_context       *context;
 	libusb_device_handle *device;
-	uint16_t              vendor_id  = 0x18d1;
-	uint16_t              product_id = 0x500f;
+	uint16_t              vendor_id  = 0x18d1; /* Google */
+	uint16_t              product_id = 0x500f; /* discovery-stm32f072 */
+	int                   interface = 1;	   /* gpio interface */
 
 	if (!(argc == 2 && strcmp(argv[1], "read")  == 0) &&
 	    !(argc == 4 && strcmp(argv[1], "write") == 0)) {
@@ -134,7 +135,7 @@ int main(int argc, char **argv)
 	}
 
 	CHECK(libusb_set_auto_detach_kernel_driver(device, 1));
-	CHECK(libusb_claim_interface(device, 0));
+	CHECK(libusb_claim_interface(device, interface));
 
 	if (argc == 2 && strcmp(argv[1], "read") == 0) {
 		uint32_t mask;