Add support for Nucleo l4r5

flake.nix

@@ -51,7 +51,7 @@
 
           arm-pkgs = builtins.attrValues {
             libopencm3 = pkgs.callPackage ./libopencm3.nix {
-              targets = [ "stm32/f2" "stm32/f4" "stm32/f7" ];
+              targets = [ "stm32/f2" "stm32/f4" "stm32/f7" "stm32/l4" ];
             };
 
             mbed-os = pkgs.callPackage ./mbed-os.nix {

hal/devices.data

@@ -3,3 +3,7 @@ stm32f407vg stm32f4 ROM=1024K RAM=128K
 stm32f4 END ROM_OFF=0x08000000 RAM_OFF=0x20000000 CPU=cortex-m4 FPU=hard-fpv4-sp-d16
 stm32f767zi stm32f7 ROM=2048K RAM=384K
 stm32f7 END ROM_OFF=0x08000000 RAM_OFF=0x20010000 CPU=cortex-m7 FPU=hard-fpv5-sp-d16
+
+# Device otherwise missing from OpenCM3
+stm32l4r5zi stm32l4 ROM=2048K RAM=256K RAM3=384K
+stm32l4 END ROM_OFF=0x08000000 RAM_OFF=0x20000000 RAM2_OFF=0x10000000 RAM3_OFF=0x20040000 CPU=cortex-m4 FPU=hard-fpv4-sp-d16

hal/hal-opencm3.c

@@ -55,6 +55,30 @@ const struct rcc_clock_scale benchmarkclock = {
 #define SERIAL_PINS (GPIO8 | GPIO9)
 #define STM32
 
+#elif defined(STM32L4R5ZI)
+#include <libopencm3/stm32/rcc.h>
+#include <libopencm3/stm32/gpio.h>
+#include <libopencm3/stm32/usart.h>
+#include <libopencm3/stm32/flash.h>
+#include <libopencm3/stm32/rng.h>
+#include <libopencm3/stm32/pwr.h>
+
+#define SERIAL_GPIO GPIOG
+#define SERIAL_USART LPUART1
+#define SERIAL_PINS (GPIO8 | GPIO7)
+#define NUCLEO_L4R5_BOARD
+
+/* Patched function for newer PLL not yet supported by opencm3 */
+void _rcc_set_main_pll(uint32_t source, uint32_t pllm, uint32_t plln, uint32_t pllp,
+                       uint32_t pllq, uint32_t pllr) {
+    RCC_PLLCFGR = (RCC_PLLCFGR_PLLM(pllm) << RCC_PLLCFGR_PLLM_SHIFT) |
+                  (plln << RCC_PLLCFGR_PLLN_SHIFT) |
+                  ((pllp & 0x1Fu) << 27u) | /* NEWER PLLP */
+                  (source << RCC_PLLCFGR_PLLSRC_SHIFT) |
+                  (pllq << RCC_PLLCFGR_PLLQ_SHIFT) |
+                  (pllr << RCC_PLLCFGR_PLLR_SHIFT) | RCC_PLLCFGR_PLLREN;
+}
+
 #else
 #error Unsupported libopencm3 board
 #endif
@@ -156,6 +180,69 @@ static void clock_setup(enum clock_mode clock) {
     # else
 # error Unsupported STM32F2 Board
     # endif
+    #elif defined(NUCLEO_L4R5_BOARD)
+    rcc_periph_clock_enable(RCC_PWR);
+    rcc_periph_clock_enable(RCC_SYSCFG);
+    pwr_set_vos_scale(PWR_SCALE1);
+    /* The L4R5ZI chip also needs the R1MODE bit in PWR_CR5 register set, but
+       OpenCM3 doesn't support this yet. But luckily the default value for the bit
+       is 1. */
+    switch (clock) {
+    case CLOCK_BENCHMARK:
+        /* Benchmark straight from the HSI16 without prescaling */
+        rcc_osc_on(RCC_HSI16);
+        rcc_wait_for_osc_ready(RCC_HSI16);
+        rcc_ahb_frequency = 20000000;
+        rcc_apb1_frequency = 20000000;
+        rcc_apb2_frequency = 20000000;
+        _clock_freq = 20000000;
+        rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
+        rcc_set_ppre1(RCC_CFGR_PPRE_NODIV);
+        rcc_set_ppre2(RCC_CFGR_PPRE_NODIV);
+        rcc_osc_off(RCC_PLL);
+        while (rcc_is_osc_ready(RCC_PLL));
+        /* Configure the PLL oscillator (use CUBEMX tool -> scale HSI16 to 20MHz). */
+        _rcc_set_main_pll(RCC_PLLCFGR_PLLSRC_HSI16, 1, 10, 2, RCC_PLLCFGR_PLLQ_DIV2, RCC_PLLCFGR_PLLR_DIV8);
+        /* Enable PLL oscillator and wait for it to stabilize. */
+        rcc_osc_on(RCC_PLL);
+        flash_dcache_enable();
+        flash_icache_enable();
+        flash_set_ws(FLASH_ACR_LATENCY_0WS);
+        flash_prefetch_enable();
+        rcc_set_sysclk_source(RCC_CFGR_SW_PLL);
+        rcc_wait_for_sysclk_status(RCC_PLL);
+        break;
+    case CLOCK_FAST:
+    default:
+        rcc_osc_on(RCC_HSI16);
+        rcc_wait_for_osc_ready(RCC_HSI16);
+        rcc_ahb_frequency = 120000000;
+        rcc_apb1_frequency = 120000000;
+        rcc_apb2_frequency = 120000000;
+        _clock_freq = 120000000;
+        rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
+        rcc_set_ppre1(RCC_CFGR_PPRE_NODIV);
+        rcc_set_ppre2(RCC_CFGR_PPRE_NODIV);
+        rcc_osc_off(RCC_PLL);
+        while (rcc_is_osc_ready(RCC_PLL));
+        /* Configure the PLL oscillator (use CUBEMX tool -> scale HSI16 to 120MHz). */
+        _rcc_set_main_pll(RCC_PLLCFGR_PLLSRC_HSI16, 1, 15, 2, RCC_PLLCFGR_PLLQ_DIV2, RCC_PLLCFGR_PLLR_DIV2);
+        /* Enable PLL oscillator and wait for it to stabilize. */
+        rcc_osc_on(RCC_PLL);
+        rcc_wait_for_osc_ready(RCC_PLL);
+        flash_dcache_enable();
+        flash_icache_enable();
+        flash_set_ws(0x05);
+        flash_prefetch_enable();
+        rcc_set_sysclk_source(RCC_CFGR_SW_PLL);
+        rcc_wait_for_sysclk_status(RCC_PLL);
+        break;
+    }
+    rcc_osc_on(RCC_HSI48); /* HSI48 must always be on for RNG */
+    rcc_wait_for_osc_ready(RCC_HSI48);
+    rcc_periph_clock_enable(RCC_RNG);
+    rcc_set_clock48_source(RCC_CCIPR_CLK48SEL_HSI48);
+    rng_enable();
     #else
 #error Unsupported platform
     #endif
@@ -171,6 +258,23 @@ void usart_setup() {
     #elif defined(NUCLEO_BOARD)
     rcc_periph_clock_enable(RCC_GPIOA);
     rcc_periph_clock_enable(RCC_USART2);
+    #elif defined(NUCLEO_L4R5_BOARD)
+    rcc_periph_clock_enable(RCC_GPIOG);
+    rcc_periph_clock_enable(RCC_LPUART1);
+
+    PWR_CR2 |= PWR_CR2_IOSV;
+    gpio_set_output_options(SERIAL_GPIO, GPIO_OTYPE_PP, GPIO_OSPEED_100MHZ, SERIAL_PINS);
+    gpio_set_af(SERIAL_GPIO, GPIO_AF8, SERIAL_PINS);
+    gpio_mode_setup(SERIAL_GPIO, GPIO_MODE_AF, GPIO_PUPD_NONE, SERIAL_PINS);
+    usart_set_baudrate(SERIAL_USART, SERIAL_BAUD);
+    usart_set_databits(SERIAL_USART, 8);
+    usart_set_stopbits(SERIAL_USART, USART_STOPBITS_1);
+    usart_set_mode(SERIAL_USART, USART_MODE_TX_RX);
+    usart_set_parity(SERIAL_USART, USART_PARITY_NONE);
+    usart_set_flow_control(SERIAL_USART, USART_FLOWCONTROL_NONE);
+    usart_disable_rx_interrupt(SERIAL_USART);
+    usart_disable_tx_interrupt(SERIAL_USART);
+    usart_enable(SERIAL_USART);
     #else
 #error Unsupported platform
     #endif

hal/nucleo_l4r5.cfg

@@ -0,0 +1,11 @@
+# SPDX-License-Identifier: Apache-2.0 or CC0-1.0
+
+# This is for STM32L4R5 Nucleo Dev Boards.
+source [find interface/stlink-dap.cfg]
+
+transport select dapdirect_swd
+
+source [find target/stm32l4x.cfg]
+
+# use hardware reset (srst seems to be problematic)
+reset_config trst_only

mk/nucleo-l4r5zi.mk

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: Apache-2.0 or CC0-1.0
+DEVICE=stm32l4r5zi
+OPENCM3_TARGET=lib/stm32/l4
+override DEVICES_DATA := hal/devices.data
+
+include mk/opencm3.mk

scripts/tests

@@ -116,6 +116,7 @@ class PLATFORM(Enum):
     MPS2_AN500 = 4
     NUCLEO_F207ZG = 5
     MPS2_AN385 = 6
+    NUCLEO_L4R5ZI = 7
 
     def __str__(self):
         return self.name.lower().replace("_", "-")
@@ -153,6 +154,9 @@ platform_map = RecursiveNamespace(
         f"{PLATFORM.MPS2_AN386}": {},
         f"{PLATFORM.MPS2_AN385}": {},
         f"{PLATFORM.MPS2_AN500}": {},
+        f"{PLATFORM.NUCLEO_L4R5ZI}": {
+            "openocd_cfg": f"{ROOT}/hal/nucleo_l4r5.cfg",
+        },
     }
 )