rpi_pico: Add hwinfo support

boards/arm/rpi_pico/doc/index.rst

@@ -60,6 +60,9 @@ hardware features:
    * - I2C
      - :kconfig:option:`CONFIG_I2C`
      - :dtcompatible:`rpi,pico-i2c`
+   * - HWINFO
+     - :kconfig:option:`CONFIG_HWINFO`
+     - N/A
 
 Programming and Debugging
 *************************

boards/arm/rpi_pico/rpi_pico.yaml

@@ -12,3 +12,4 @@ supported:
   - uart
   - gpio
   - i2c
+  - hwinfo

cmake/compiler/compiler_flags_template.cmake

@@ -108,3 +108,6 @@ set_property(TARGET compiler-cpp PROPERTY no_threadsafe_statics)
 
 # Required ASM flags when compiling
 set_property(TARGET asm PROPERTY required)
+
+# Compiler flag for disabling pointer arithmetic warnings
+set_compiler_property(PROPERTY warning_no_pointer_arithmetic)

cmake/compiler/gcc/compiler_flags.cmake

@@ -189,3 +189,6 @@ set_property(TARGET asm PROPERTY required "-xassembler-with-cpp")
 if (NOT COMPILER STREQUAL "xcc")
 set_compiler_property(PROPERTY diagnostic -fdiagnostics-color=always)
 endif()
+
+# Compiler flag for disabling pointer arithmetic warnings
+set_compiler_property(PROPERTY warning_no_pointer_arithmetic "-Wno-pointer-arith")

drivers/hwinfo/CMakeLists.txt

@@ -16,6 +16,7 @@ zephyr_library_sources_ifdef(CONFIG_HWINFO_MCUX_SRC    hwinfo_mcux_src.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_MCUX_SYSCON hwinfo_mcux_syscon.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_NRF         hwinfo_nrf.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_PSOC6       hwinfo_psoc6.c)
+zephyr_library_sources_ifdef(CONFIG_HWINFO_RPI_PICO    hwinfo_rpi_pico.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_SAM_RSTC    hwinfo_sam_rstc.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_SAM         hwinfo_sam.c)
 zephyr_library_sources_ifdef(CONFIG_HWINFO_SAM0        hwinfo_sam0.c)

drivers/hwinfo/Kconfig

@@ -70,6 +70,14 @@ config HWINFO_IMXRT
 	help
 	  Enable NXP i.mx RT hwinfo driver.
 
+config HWINFO_RPI_PICO
+	bool "Raspberry Pi Pico hwinfo driver"
+	default y
+	depends on SOC_SERIES_RP2XXX
+	select PICOSDK_USE_FLASH
+	help
+	  Enable Raspberry Pi Pico hwinfo driver.
+
 config HWINFO_SAM_RSTC
 	bool "Atmel SAM reset cause"
 	default y

drivers/hwinfo/hwinfo_rpi_pico.c

@@ -0,0 +1,74 @@
+/*
+ * Copyright (c) 2022 Yonatan Schachter
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <string.h>
+#include <drivers/hwinfo.h>
+#include <hardware/flash.h>
+#include <hardware/structs/vreg_and_chip_reset.h>
+
+#define FLASH_RUID_DATA_BYTES 8
+
+#define HAD_RUN_BIT BIT(VREG_AND_CHIP_RESET_CHIP_RESET_HAD_RUN_LSB)
+#define HAD_PSM_RESTART_BIT BIT(VREG_AND_CHIP_RESET_CHIP_RESET_HAD_PSM_RESTART_LSB)
+#define HAD_POR_BIT BIT(VREG_AND_CHIP_RESET_CHIP_RESET_HAD_POR_LSB)
+
+ssize_t z_impl_hwinfo_get_device_id(uint8_t *buffer, size_t length)
+{
+	uint8_t id[FLASH_RUID_DATA_BYTES];
+	uint32_t key;
+
+	/*
+	 * flash_get_unique_id temporarily disables XIP to query the
+	 * flash for its ID. If the CPU is interrupted while XIP is
+	 * disabled, it will halt. Therefore, interrupts must be disabled
+	 * before fetching the ID.
+	 */
+	key = irq_lock();
+	flash_get_unique_id(id);
+	irq_unlock(key);
+
+	if (length > sizeof(id)) {
+		length = sizeof(id);
+	}
+	memcpy(buffer, id, length);
+
+	return length;
+}
+
+int z_impl_hwinfo_get_reset_cause(uint32_t *cause)
+{
+	uint32_t flags = 0;
+	uint32_t reset_register = vreg_and_chip_reset_hw->chip_reset;
+
+	if (reset_register & HAD_POR_BIT) {
+		flags |= RESET_POR;
+	}
+
+	if (reset_register & HAD_RUN_BIT) {
+		flags |= RESET_PIN;
+	}
+
+	if (reset_register & HAD_PSM_RESTART_BIT) {
+		flags |= RESET_DEBUG;
+	}
+
+	*cause = flags;
+	return 0;
+}
+
+int z_impl_hwinfo_clear_reset_cause(void)
+{
+	/* The reset register can't be modified, nothing to do. */
+
+	return -ENOSYS;
+}
+
+int z_impl_hwinfo_get_supported_reset_cause(uint32_t *supported)
+{
+	*supported = RESET_PIN | RESET_DEBUG | RESET_POR;
+
+	return 0;
+}

include/drivers/hwinfo.h

@@ -63,7 +63,7 @@ extern "C" {
  * @param length  Max length of the buffer.
  *
  * @retval size of the device ID copied.
- * @retval -ENOTSUP if there is no implementation for the particular device.
+ * @retval -ENOSYS if there is no implementation for the particular device.
  * @retval any negative value on driver specific errors.
  */
 __syscall ssize_t hwinfo_get_device_id(uint8_t *buffer, size_t length);
@@ -87,7 +87,7 @@ ssize_t z_impl_hwinfo_get_device_id(uint8_t *buffer, size_t length);
  * `hwinfo_clear_reset_cause` has been called.
  *
  * @retval zero if successful.
- * @retval -ENOTSUP if there is no implementation for the particular device.
+ * @retval -ENOSYS if there is no implementation for the particular device.
  * @retval any negative value on driver specific errors.
  */
 __syscall int hwinfo_get_reset_cause(uint32_t *cause);
@@ -100,7 +100,7 @@ int z_impl_hwinfo_get_reset_cause(uint32_t *cause);
  * Clears reset cause flags.
  *
  * @retval zero if successful.
- * @retval -ENOTSUP if there is no implementation for the particular device.
+ * @retval -ENOSYS if there is no implementation for the particular device.
  * @retval any negative value on driver specific errors.
  */
 __syscall int hwinfo_clear_reset_cause(void);
@@ -115,7 +115,7 @@ int z_impl_hwinfo_clear_reset_cause(void);
  * Retrieves all `reset_cause` flags that are supported by this device.
  *
  * @retval zero if successful.
- * @retval -ENOTSUP if there is no implementation for the particular device.
+ * @retval -ENOSYS if there is no implementation for the particular device.
  * @retval any negative value on driver specific errors.
  */
 __syscall int hwinfo_get_supported_reset_cause(uint32_t *supported);

modules/hal_rpi_pico/CMakeLists.txt

@@ -50,6 +50,7 @@ if(CONFIG_HAS_RPI_PICO)
     ${rp2_common_dir}/hardware_xosc/xosc.c
     ${rp2_common_dir}/hardware_watchdog/watchdog.c
     ${rp2_common_dir}/pico_platform/platform.c
+    ${rp2_common_dir}/pico_bootrom/bootrom.c
   )
 
   zephyr_include_directories(
@@ -62,6 +63,7 @@ if(CONFIG_HAS_RPI_PICO)
     ${rp2_common_dir}/hardware_sync/include
     ${rp2_common_dir}/hardware_timer/include
     ${rp2_common_dir}/hardware_resets/include
+    ${rp2_common_dir}/pico_bootrom/include
     ${rp2040_dir}/hardware_regs/include
     ${rp2040_dir}/hardware_structs/include
     ${common_dir}/pico_base/include
@@ -78,4 +80,21 @@ if(CONFIG_HAS_RPI_PICO)
           ${rp2_common_dir}/hardware_uart/uart.c)
   zephyr_include_directories_ifdef(CONFIG_PICOSDK_USE_UART
           ${rp2_common_dir}/hardware_uart/include)
+
+  zephyr_library_sources_ifdef(CONFIG_PICOSDK_USE_FLASH
+          ${rp2_common_dir}/hardware_flash/flash.c)
+  zephyr_include_directories_ifdef(CONFIG_PICOSDK_USE_FLASH
+          ${rp2_common_dir}/hardware_flash/include)
+
+  # Some flash driver functions must be executed from the RAM.
+  # Originally pico-sdk places them in the RW data section, so this
+  # implementation does the same.
+  zephyr_linker_sources_ifdef(CONFIG_PICOSDK_USE_FLASH RWDATA timecritical.ld)
+
+  # A function in flash.c adds 1 to a function pointer, causing a warning
+  set_source_files_properties(
+    ${rp2_common_dir}/hardware_flash/flash.c
+    PROPERTIES
+    COMPILE_FLAGS $<TARGET_PROPERTY:compiler,warning_no_pointer_arithmetic>
+  )
 endif()

modules/hal_rpi_pico/Kconfig

@@ -13,3 +13,8 @@ config PICOSDK_USE_GPIO
 	bool
 	help
 	  Use the GPIO driver from pico-sdk
+
+config PICOSDK_USE_FLASH
+	bool
+	help
+	  Use the flash driver from pico-sdk

modules/hal_rpi_pico/pico/config_autogen.h

@@ -35,4 +35,11 @@
 #define __always_inline ALWAYS_INLINE
 #endif /* __always_inline */
 
+/* Two definitions required for the flash driver */
+#define __STRING(x) #x
+
+#ifndef __noinline
+#define __noinline __attribute__((noinline))
+#endif
+
 #endif

modules/hal_rpi_pico/timecritical.ld

@@ -0,0 +1 @@
+*(.time_critical*)