Feature: Fancy DFU on blackpill-f4

src/platforms/common/blackpill-f4/blackpill-f4.c

@@ -45,10 +45,11 @@ volatile uint32_t magic[2] __attribute__((section(".noinit")));
 
 void platform_init(void)
 {
-	/* Enable GPIO peripherals */
+	/* Enable peripherals */
 	rcc_periph_clock_enable(RCC_GPIOA);
 	rcc_periph_clock_enable(RCC_GPIOC);
 	rcc_periph_clock_enable(RCC_GPIOB);
+	rcc_periph_clock_enable(RCC_CRC);
 
 #ifndef BMP_BOOTLOADER
 	/* Blackpill board has a floating button on PA0. Pull it up and use as active-low. */
@@ -73,26 +74,19 @@ void platform_init(void)
 #endif
 	rcc_clock_setup_pll(&rcc_hse_25mhz_3v3[PLATFORM_CLOCK_FREQ]);
 
-	/* Enable peripherals */
-	rcc_periph_clock_enable(RCC_OTGFS);
-	rcc_periph_clock_enable(RCC_CRC);
-
 	/* Set up DM/DP pins. PA9/PA10 are not routed to USB-C. */
 	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO11 | GPIO12);
 	gpio_set_af(GPIOA, GPIO_AF10, GPIO11 | GPIO12);
 
-	GPIOA_OSPEEDR &= 0x3c00000cU;
-	GPIOA_OSPEEDR |= 0x28000008U;
-
 	/* Set up TDI, TDO, TCK and TMS pins */
 	gpio_mode_setup(TDI_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, TDI_PIN);
 	gpio_mode_setup(TDO_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, TDO_PIN);
 	gpio_mode_setup(TCK_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, TCK_PIN);
 	gpio_mode_setup(TMS_PORT, GPIO_MODE_INPUT, GPIO_PUPD_NONE, TMS_PIN);
-	gpio_set_output_options(TDI_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, TDI_PIN);
-	gpio_set_output_options(TDO_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, TDO_PIN);
-	gpio_set_output_options(TCK_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, TCK_PIN);
-	gpio_set_output_options(TMS_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_2MHZ, TMS_PIN);
+	gpio_set_output_options(TDI_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_25MHZ, TDI_PIN);
+	gpio_set_output_options(TDO_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_25MHZ, TDO_PIN);
+	gpio_set_output_options(TCK_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_25MHZ, TCK_PIN);
+	gpio_set_output_options(TMS_PORT, GPIO_OTYPE_PP, GPIO_OSPEED_25MHZ, TMS_PIN);
 
 	/* Set up LED pins */
 	gpio_mode_setup(LED_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_IDLE_RUN | LED_ERROR | LED_BOOTLOADER);
@@ -114,6 +108,9 @@ void platform_init(void)
 	/* https://github.com/libopencm3/libopencm3/pull/1256#issuecomment-779424001 */
 	OTG_FS_GCCFG |= OTG_GCCFG_NOVBUSSENS | OTG_GCCFG_PWRDWN;
 	OTG_FS_GCCFG &= ~(OTG_GCCFG_VBUSBSEN | OTG_GCCFG_VBUSASEN);
+
+	/* By default, do not drive the SWD bus too fast. */
+	platform_max_frequency_set(3000000);
 }
 
 void platform_nrst_set_val(bool assert)

src/platforms/common/blackpill-f4/usbdfu.c

@@ -19,9 +19,10 @@
 
 #include <string.h>
 #include <libopencm3/cm3/systick.h>
+#include <libopencm3/cm3/nvic.h>
+#include <libopencm3/cm3/scb.h>
 #include <libopencm3/stm32/rcc.h>
 #include <libopencm3/stm32/gpio.h>
-#include <libopencm3/cm3/scb.h>
 #include <libopencm3/usb/dwc/otg_fs.h>
 
 #include "usbdfu.h"
@@ -30,6 +31,9 @@
 
 uintptr_t app_address = 0x08004000U;
 volatile uint32_t magic[2] __attribute__((section(".noinit")));
+static uint32_t dfu_activity_counter;
+
+static void sys_tick_init(void);
 
 void dfu_detach(void)
 {
@@ -38,6 +42,7 @@ void dfu_detach(void)
 
 int main(void)
 {
+	/* Enable GPIO peripherals */
 	rcc_periph_clock_enable(RCC_GPIOA);
 
 	/* Blackpill board has a floating button on PA0. Pull it up and use as active-low. */
@@ -53,11 +58,11 @@ int main(void)
 
 	/* Assert blue LED as indicator we are in the bootloader */
 	rcc_periph_clock_enable(RCC_GPIOC);
-	gpio_mode_setup(LED_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_BOOTLOADER);
-	gpio_set(LED_PORT, LED_BOOTLOADER);
+	gpio_mode_setup(LED_PORT, GPIO_MODE_OUTPUT, GPIO_PUPD_NONE, LED_BOOTLOADER | LED_IDLE_RUN);
+	gpio_clear(LED_PORT, LED_BOOTLOADER | LED_IDLE_RUN);
 
-	/* Enable peripherals */
-	rcc_periph_clock_enable(RCC_OTGFS);
+	/* Run heartbeat on blue LED */
+	sys_tick_init();
 
 	/* Set up USB Pins and alternate function*/
 	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO11 | GPIO12);
@@ -75,4 +80,46 @@ int main(void)
 
 void dfu_event(void)
 {
+	static bool idle_state = false;
+	/* Ask systick to pause blinking for 1 second */
+	dfu_activity_counter = 10U;
+	/* Toggle-blink it ourself */
+	SET_IDLE_STATE(idle_state);
+	idle_state = !idle_state;
+}
+
+static void sys_tick_init(void)
+{
+	/* Use SysTick at 10Hz to toggle-blink the blue LED at 5 Hz */
+	systick_set_clocksource(STK_CSR_CLKSOURCE_AHB_DIV8);
+	systick_set_reload(rcc_ahb_frequency / 8U / 10U);
+	/* SYSTICK_IRQ with low priority */
+	nvic_set_priority(NVIC_SYSTICK_IRQ, 14U << 4U);
+	systick_interrupt_enable();
+	/* Start the heartbeat timer */
+	systick_counter_enable();
+}
+
+void sys_tick_handler(void)
+{
+	static uint32_t count = 0U;
+	if (dfu_activity_counter > 0U) {
+		dfu_activity_counter--;
+		return;
+	}
+	switch (count) {
+	case 0U:
+		/* Reload downcounter and disable LED */
+		count = 10U;
+		SET_IDLE_STATE(false);
+		break;
+	case 1U:
+		count--;
+		/* Enable LED for 1/10th of cycle */
+		SET_IDLE_STATE(true);
+		break;
+	default:
+		count--;
+		break;
+	}
 }

src/platforms/common/stm32/dfu_f4.c

@@ -17,6 +17,32 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/*
+ * References, ST datasheets:
+ *
+ * DS8626 - STM32F405xx/407xx Rev 9 pg108, Table 40. Flash memory programming
+ *   https://www.st.com/resource/en/datasheet/stm32f407vg.pdf
+ *   (f4discovery:stm32f407vg, 128/1024 KiB;
+ *    hydrabus:stm32f405rg, 128/1024 KiB)
+ *
+ * DS9716 - STM32F401xB/xC Rev 11 pg85, Table 45. Flash memory programming
+ *   https://www.st.com/resource/en/datasheet/stm32f401cb.pdf
+ *   (blackpill-f4:stm32f401cc, 64/256 KiB)
+ *
+ * DS10086 - STM32F401xD/xE Rev 3 pg86, Table 45. Flash memory programming
+ *   https://www.st.com/resource/en/datasheet/stm32f401re.pdf
+ *   (blackpill-f4:stm32f401ce, 96/512 KiB;
+ *    96b_carbon:stm32f401re, 96/512 KiB)
+ *
+ * DS10314 - STM32F411xC/xE Rev 7 pg92, Table 45. Flash memory programming
+ *   https://www.st.com/resource/en/datasheet/stm32f411ce.pdf
+ *   (blackpill-f4:stm32f411ce, 128/512 KiB)
+ *
+ * DS11853 - STM32F722xx/723xx Rev 9 pg138, Table 53. Flash memory programming
+ *   https://www.st.com/resource/en/datasheet/stm32f723ie.pdf
+ *   (stlinkv3:stm32f723ie, 256/512 KiB; and F7 has slightly smaller timings than F4 family)
+ */
+
 #include "general.h"
 #include "usbdfu.h"
 
@@ -41,7 +67,29 @@ static uint32_t sector_addr[] = {
 	0,
 };
 
-static uint16_t sector_erase_time[] = {500, 500, 500, 500, 1100, 2600, 2600, 2600, 2600, 2600, 2600, 2600, 2600};
+/* Sector erase times in milliseconds, typ, for x32 parallelism at 2.7-3.6v */
+typedef enum erase_times_f4 {
+	ERASE_TIME_16KB = 250,   /*  500 * 0.5 */
+	ERASE_TIME_64KB = 550,   /* 1100 * 0.5 */
+	ERASE_TIME_128KB = 1000, /* 2000 * 0.5 */
+} erase_times_f4_e;
+
+static erase_times_f4_e sector_erase_time[] = {
+	ERASE_TIME_16KB,
+	ERASE_TIME_16KB,
+	ERASE_TIME_16KB,
+	ERASE_TIME_16KB,
+	ERASE_TIME_64KB,
+	ERASE_TIME_128KB,
+	ERASE_TIME_128KB,
+	ERASE_TIME_128KB,
+	ERASE_TIME_128KB,
+	ERASE_TIME_128KB,
+	ERASE_TIME_128KB,
+	ERASE_TIME_128KB,
+	ERASE_TIME_128KB,
+};
+
 static uint8_t sector_num = 0xff;
 
 static_assert(ARRAY_LENGTH(sector_erase_time) == ARRAY_LENGTH(sector_addr) - 1U,
@@ -75,20 +123,25 @@ void dfu_flash_program_buffer(const uint32_t baseaddr, const void *const buf, co
 	const uint32_t *const buffer = (const uint32_t *)buf;
 	for (size_t i = 0; i < len; i += 4U)
 		flash_program_word(baseaddr + i, buffer[i >> 2U]);
+
+	/* Call the platform specific dfu event callback. */
+	dfu_event();
 }
 
 uint32_t dfu_poll_timeout(uint8_t cmd, uint32_t addr, uint16_t blocknum)
 {
-	/* Erase for big pages on STM2/4 needs "long" time
-	   Try not to hit USB timeouts*/
+	/*
+	 * Sector erase for big pages of STM32 F2/F4/F7 needs "long" time,
+	 * up to 1-2 seconds. Try not to hit USB timeouts.
+	 */
 	if (blocknum == 0 && cmd == CMD_ERASE) {
 		get_sector_num(addr);
 		if (addr == sector_addr[sector_num])
 			return sector_erase_time[sector_num];
 	}
 
-	/* Programming 256 word with 100 us(max) per word*/
-	return 26U;
+	/* Programming 256 words (32-bit) with 16 us(typ), 100 us(max) per word */
+	return 16U * 1024U / 4U / 1000U;
 }
 
 void dfu_protect(bool enable)