prepare to support more targets

Author: dword1511

Makefile

@@ -9,7 +9,7 @@
 PROGRAM     = stm32-vserprog
 CROSS      ?= arm-none-eabi
 SERIAL     ?= /dev/ttyUSB0
-BOARD      ?= stm32-vserprog-v2
+BOARD      ?= stm32-vserprog-v3
 OBJS        = vserprog.o \
               usbcdc.o \
               spi.o \

README.md

@@ -1,5 +1,5 @@
 # stm32-vserprog:
-## flashrom serprog programmer based on STM32F103 MCU & USB CDC protocol.
+## flashrom serprog programmer based on STM32 MCU & USB CDC protocol.
 **This project deprecates previous [serprog-stm32vcp](https://github.com/dword1511/serprog-stm32vcp) project, which uses STMicro's proprietary firmware library. Most functions are the same.**
 
 * * *
@@ -9,11 +9,11 @@
   * A STM32F103C8T6 MCU, a 8MHz crystal, a 3.3V 1117 LDO, some 0805 capacitors, resistors and LEDs along with dedicated [PCB available on OSH Park](https://oshpark.com/shared_projects/08Rj6sSm)
   * Or some general-purpose STM32F103 development boards, just with minor modifications in the source code to assign correct GPIO for USB D+ pullup and LEDs.
   * Hardware USB2.0 FullSpeed and efficient virtual COM port with USB CDC protocol eliminates the need of USB-to-UART bridges and the headache that comes with them, operates at any baud rates.
-  * *Ironically, you will still have to buy or borrow a USB-to-UART bridge (not RS-232 but TTL level) to program the programmer itself.*
-* Hardware full-duplex SPI with DMA, multiple clock speeds available:
-  * 36MHz *(Default)*
+  * *Ironically, you will still have to buy or borrow a USB-to-UART bridge (not RS-232 but TTL level) to program the programmer itself,* unless you are using a STM32F042 device (support is in progress).
+* Hardware full-duplex SPI with DMA, multiple clock speeds available (default at the one closest to but under 10MHz), e.g. on STM32F103 targets:
+  * 36MHz
   * 18MHz
-  * 9MHz
+  * 9MHz *(Default)*
   * 4.5MHz
   * 2.25MHz
   * 1.125MHz
@@ -45,11 +45,11 @@
 
 1. Clone and compile.
 
-  Simply type:
+  Simply type (change the board name accordingly, for details see the header of the Makefile):
 
    ```bash
    git clone https://github.com/dword1511/stm32-vserprog.git
-   make
+   make BOARD=stm32-vserprog-v2
    ```
 1. Program.
 
@@ -58,7 +58,7 @@
   Then type:
 
    ```bash
-   make flash
+   make BOARD=stm32-vserprog-v2 flash
    ```
 1. Done!
 

boards/stm32-tiny042-v1.h

@@ -0,0 +1,19 @@
+#ifndef __BOARD_H__
+#define __BOARD_H__
+
+#include <stdbool.h>
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+
+#define BOARD_USE_DEBUG_PINS_AS_GPIO false
+
+#define BOARD_RCC_LED                RCC_GPIOA
+#define BOARD_PORT_LED               GPIOA
+#define BOARD_PIN_LED                GPIO14
+#define BOARD_LED_HIGH_IS_BUSY       false /* Only LED, high active, use as idle. */
+
+/* STM32F0x2 has internal USB pullup. */
+
+/* Currently you can only use SPI1, since it has highest clock. */
+
+#endif /* __BOARD_H__ */

boards/stm32-tiny042-v1.mk

@@ -0,0 +1 @@
+stm32f042.mk

boards/stm32f042.mk

@@ -0,0 +1,4 @@
+ARCH_FLAGS = -DSTM32F0 -mthumb -mcpu=cortex-m0 -msoft-float
+LDSCRIPT   = libopencm3/lib/stm32/f0/stm32f04xz6.ld
+LIBOPENCM3 = libopencm3/lib/libopencm3_stm32f0.a
+OPENCM3_MK = lib/stm32/f0

flashrom

@@ -21,44 +21,44 @@ uint32_t spi_setup(uint32_t speed_hz) {
   rcc_periph_clock_enable(RCC_SPI1);
   rcc_periph_clock_enable(RCC_DMA1);
 
-  /* SPI1 is on APB2 which runs at 72MHz. Assume f = f_PCLK / 2 = 36MHz (whereas datasheet says 16MHz max but reference manual has no such word). */
+  /* SPI1 is on APB2 which runs at 72MHz. Assume f = f_PCLK / 2 = 36MHz (whereas datasheet says 18MHz max but reference manual has no such word). */
   /* Lowest available */
   clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_256;
-  relspd = 281250;
+  relspd = rcc_apb2_frequency / 256;
 
-  if(speed_hz >= 562500) {
+  if(speed_hz >= rcc_apb2_frequency / 128) {
     clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_128;
-    relspd = 562500;
+    relspd = rcc_apb2_frequency / 128;
   }
 
-  if(speed_hz >= 1125000) {
+  if(speed_hz >= rcc_apb2_frequency / 64) {
     clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_64;
-    relspd = 1125000;
+    relspd = rcc_apb2_frequency / 64;
   }
 
-  if(speed_hz >= 2250000) {
+  if(speed_hz >= rcc_apb2_frequency / 32) {
     clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_32;
-    relspd = 2250000;
+    relspd = rcc_apb2_frequency / 32;
   }
 
-  if(speed_hz >= 4500000) {
+  if(speed_hz >= rcc_apb2_frequency / 16) {
     clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_16;
-    relspd = 4500000;
+    relspd = rcc_apb2_frequency / 16;
   }
 
-  if(speed_hz >= 9000000) {
+  if(speed_hz >= rcc_apb2_frequency / 8) {
     clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_8;
-    relspd = 9000000;
+    relspd = rcc_apb2_frequency / 8;
   }
 
-  if(speed_hz >= 18000000) {
+  if(speed_hz >= rcc_apb2_frequency / 4) {
     clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_4;
-    relspd = 18000000;
+    relspd = rcc_apb2_frequency / 4;
   }
 
-  if(speed_hz >= 36000000) {
+  if(speed_hz >= rcc_apb2_frequency / 2) {
     clkdiv = SPI_CR1_BAUDRATE_FPCLK_DIV_2;
-    relspd = 36000000;
+    relspd = rcc_apb2_frequency / 2;
   }
 
   /* Configure GPIOs: SS = PA4, SCK = PA5, MISO = PA6, MOSI = PA7 */

libopencm3

@@ -6,7 +6,7 @@
 
 #include <libopencm3/stm32/gpio.h>
 
-#define SPI_DEFAULT_CLOCK 36000000
+#define SPI_DEFAULT_CLOCK 10000000
 
 #define SPI_SELECT()   gpio_clear(GPIOA, GPIO_SPI1_NSS)
 #define SPI_UNSELECT() gpio_set(GPIOA, GPIO_SPI1_NSS)

spi.c

@@ -231,28 +231,91 @@ void handle_command(unsigned char command) {
   LED_IDLE();
 }
 
+#ifdef GD32F103
+void rcc_clock_setup_in_hse_12mhz_out_120mhz(void) {
+  /* Enable internal high-speed oscillator. */
+  rcc_osc_on(RCC_HSI);
+  rcc_wait_for_osc_ready(RCC_HSI);
+
+  /* Select HSI as SYSCLK source. */
+  rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSICLK);
+
+  /* Enable external high-speed oscillator 12MHz. */
+  rcc_osc_on(RCC_HSE);
+  rcc_wait_for_osc_ready(RCC_HSE);
+  rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_HSECLK);
+
+  /*
+   * Set prescalers for AHB, ADC, ABP1, ABP2.
+   * Do this before touching the PLL (TODO: why?).
+   */
+  rcc_set_hpre(RCC_CFGR_HPRE_SYSCLK_NODIV);      /* Set. 120MHz Max. 108MHz */
+  RCC_CFGR = (RCC_CFGR & ~RCC_CFGR_ADCPRE) | ((uint32_t)0x10004000); /* ADC Set. 12MHz  Max. 14MHz  */
+  rcc_set_ppre1(RCC_CFGR_PPRE1_HCLK_DIV2);       /* Set. 60MHz  Max. 54MHz  */
+  rcc_set_ppre2(RCC_CFGR_PPRE2_HCLK_NODIV);      /* Set. 120MHz Max. 108MHz */
+  RCC_CFGR |= ((uint32_t)0x00800000);            /* USB Set. 48MHz  Max. 48MHz  */
+
+  /* GD32 has 0-wait-state flash */
+  flash_set_ws(FLASH_ACR_LATENCY_0WS);
+
+  /*
+   * Set the PLL multiplication factor to 10.
+   * 12MHz (external) * 10 (multiplier) = 120MHz
+   */
+  rcc_set_pll_multiplication_factor(RCC_CFGR_PLLMUL_PLL_CLK_MUL10);
+
+  /* Select HSE as PLL source. */
+  rcc_set_pll_source(RCC_CFGR_PLLSRC_HSE_CLK);
+
+  /*
+   * External frequency undivided before entering PLL
+   * (only valid/needed for HSE).
+   */
+  rcc_set_pllxtpre(RCC_CFGR_PLLXTPRE_HSE_CLK);
+
+  /* Enable PLL oscillator and wait for it to stabilize. */
+  rcc_osc_on(RCC_PLL);
+  rcc_wait_for_osc_ready(RCC_PLL);
+
+  /* Select PLL as SYSCLK source. */
+  rcc_set_sysclk_source(RCC_CFGR_SW_SYSCLKSEL_PLLCLK);
+
+  /* Set the peripheral clock frequencies used */
+  rcc_ahb_frequency  = 120000000;
+  rcc_apb1_frequency = 60000000;
+  rcc_apb2_frequency = 120000000;
+}
+#endif /* GD32F103 */
+
 int main(void) {
   uint32_t i;
 
   rcc_periph_clock_enable(BOARD_RCC_LED);
   LED_ENABLE();
   LED_BUSY();
 
+#ifdef GD32F103
+  rcc_clock_setup_in_hse_12mhz_out_120mhz();
+#else
   rcc_clock_setup_in_hse_8mhz_out_72mhz();
+#endif /* GD32F103 */
+
   rcc_periph_clock_enable(RCC_GPIOA); /* For USB */
   rcc_periph_clock_enable(BOARD_RCC_USB_PULLUP);
   rcc_periph_clock_enable(RCC_AFIO); /* For SPI */
 #if BOARD_USE_DEBUG_PINS_AS_GPIO
   gpio_primary_remap(AFIO_MAPR_SWJ_CFG_JTAG_OFF_SW_OFF, AFIO_MAPR_TIM2_REMAP_FULL_REMAP);
 #endif
 
-  /* Setup PB3 to pull up the D+ high. */
+#ifndef STM32F0
+  /* Setup GPIO to pull up the D+ high. */
   gpio_set_mode(BOARD_PORT_USB_PULLUP, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, BOARD_PIN_USB_PULLUP);
 #if BOARD_USB_HIGH_IS_PULLUP
   gpio_set(BOARD_PORT_USB_PULLUP, BOARD_PIN_USB_PULLUP);
 #else
   gpio_clear(BOARD_PORT_USB_PULLUP, BOARD_PIN_USB_PULLUP);
-#endif
+#endif /* BOARD_USB_HIGH_IS_PULLUP */
+#endif /* STM32F0 */
 
   usbcdc_init();
   spi_setup(SPI_DEFAULT_CLOCK);