logging: add driver for i2c log backend

It's usually used to output FW log to i2c FDTI device connected on ISH boards.

Signed-off-by: Dong Wang <[email protected]>

zephyr/CMakeLists.txt

@@ -39,4 +39,5 @@ if(CONFIG_INTEL_HAL)
       zephyr_library_sources(${BSP_SEDI_SOC_DIR}/sedi_soc.c)
   endif()
 
+  add_subdirectory(subsys/logging/backends)
 endif()

zephyr/Kconfig

@@ -0,0 +1,12 @@
+# Kconfig - Intel HAL Zephyr configuration options
+#
+# Copyright (c) 2024 Intel Corporation.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+menu "Intel HAL Zephyr Configuration"
+
+rsource "subsys/logging/backends/Kconfig.i2c"
+
+endmenu

zephyr/module.yml

@@ -1,3 +1,4 @@
 name: hal_intel
 build:
   cmake: zephyr
+  kconfig: zephyr/Kconfig

zephyr/subsys/logging/backends/CMakeLists.txt

@@ -0,0 +1,8 @@
+# Copyright (c) 2024 Intel Corporation Inc.
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if (CONFIG_LOG)
+  zephyr_sources_ifdef(CONFIG_LOG_BACKEND_I2C log_backend_i2c.c)
+endif()

zephyr/subsys/logging/backends/Kconfig.i2c

@@ -0,0 +1,40 @@
+#
+# Copyright (c) 2024 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+if LOG
+
+config LOG_BACKEND_I2C
+	bool "Enable I2C log backend"
+	depends on I2C_SEDI
+	select LOG_OUTPUT
+	help
+	  When enabled, backend will use I2C for logging.
+
+if LOG_BACKEND_I2C
+
+config LOG_BACKEND_I2C_AUTOSTART
+	bool "Automatically start I2C backend"
+	default y
+	help
+	  When enabled automatically start the I2C logging backend on
+	  application start. When disabled, the application needs to start
+	  the backend manually using log_backend_enable().
+
+backend = I2C
+backend-str = i2c
+source "subsys/logging/Kconfig.template.log_format_config"
+
+config LOG_I2C_MAX_MSG_LEN
+	int "Maximum message length"
+	default 256
+
+config LOG_I2C_DEV_ADDR
+	hex "I2C address of I2C log device"
+	default 0x5E
+
+endif # LOG_BACKEND_I2C
+
+endif # LOG

zephyr/subsys/logging/backends/log_backend_i2c.c

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) 2024 Intel Corporation.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/logging/log_backend.h>
+#include <zephyr/logging/log_core.h>
+#include <zephyr/logging/log_ctrl.h>
+#include <zephyr/logging/log_msg.h>
+#include <zephyr/logging/log_output.h>
+#include <zephyr/logging/log_backend_std.h>
+#include <zephyr/sys/__assert.h>
+#include <sedi_driver_i2c.h>
+
+static uint32_t log_format_current = CONFIG_LOG_BACKEND_I2C_OUTPUT_DEFAULT;
+static uint8_t log_i2c_buf[CONFIG_LOG_I2C_MAX_MSG_LEN];
+static bool panic_mode;
+static uint8_t i2c_bus;
+
+static int log_i2c_char_out(uint8_t *data, size_t length, void *ctx)
+{
+	ARG_UNUSED(ctx);
+
+	__ASSERT_NO_MSG(length > 0 && length <= CONFIG_LOG_I2C_MAX_MSG_LEN);
+
+	sedi_i2c_master_poll_write(i2c_bus, CONFIG_LOG_I2C_DEV_ADDR,
+				data, length, false);
+
+	return length;
+}
+
+LOG_OUTPUT_DEFINE(log_output_i2c, log_i2c_char_out,
+		log_i2c_buf, CONFIG_LOG_I2C_MAX_MSG_LEN);
+
+static void log_i2c_panic(struct log_backend const *const backend)
+{
+	ARG_UNUSED(backend);
+
+	panic_mode = true;
+	sedi_i2c_control(i2c_bus, SEDI_I2C_ABORT_TRANSFER, 0);
+	log_backend_std_panic(&log_output_i2c);
+}
+
+static void log_i2c_dropped(const struct log_backend *const backend,
+		uint32_t cnt)
+{
+	ARG_UNUSED(backend);
+
+	log_backend_std_dropped(&log_output_i2c, cnt);
+}
+
+static void process(const struct log_backend *const backend,
+		union log_msg_generic *msg)
+{
+	uint32_t flags = log_backend_std_get_flags();
+	log_format_func_t log_output_func = log_format_func_t_get(log_format_current);
+
+	log_output_func(&log_output_i2c, &msg->log, flags);
+}
+
+static int format_set(const struct log_backend *const backend, uint32_t log_type)
+{
+	log_format_current = log_type;
+	return 0;
+}
+
+static void log_backend_i2c_init(const struct log_backend *const backend)
+{
+#if DT_HAS_CHOSEN(zephyr_log_i2c)
+	uint32_t cfg = I2C_SPEED_SET(I2C_SPEED_FAST) | I2C_MODE_CONTROLLER;
+	int ret = i2c_configure(DEVICE_DT_GET(DT_CHOSEN(zephyr_log_i2c)), cfg);
+
+	if (ret) {
+		goto disable;
+	}
+
+	i2c_bus = DT_PROP(DT_CHOSEN(zephyr_log_i2c), peripheral_id);
+	panic_mode = false;
+
+	return;
+
+disable:
+#endif
+	/* No specified log i2c device or device not ready */
+	log_backend_disable(backend);
+}
+
+static const struct log_backend_api log_backend_i2c_api = {
+	.process = process,
+	.panic = log_i2c_panic,
+	.init = log_backend_i2c_init,
+	.dropped = IS_ENABLED(CONFIG_LOG_MODE_IMMEDIATE) ? NULL : log_i2c_dropped,
+	.format_set = format_set,
+};
+
+LOG_BACKEND_DEFINE(log_backend_i2c, log_backend_i2c_api,
+		IS_ENABLED(CONFIG_LOG_BACKEND_I2C_AUTOSTART));