console: ipm_console: Add console over IPM

Add console over Inter Processor Mailboxes (IPM).
This is useful for AMP processors like ADSP found on up_squared board.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>

drivers/console/CMakeLists.txt

@@ -5,6 +5,7 @@ zephyr_sources_ifdef(CONFIG_RAM_CONSOLE ram_console.c)
 zephyr_sources_ifdef(CONFIG_RTT_CONSOLE rtt_console.c)
 zephyr_sources_ifdef(CONFIG_IPM_CONSOLE_RECEIVER ipm_console_receiver.c)
 zephyr_sources_ifdef(CONFIG_IPM_CONSOLE_SENDER ipm_console_sender.c)
+zephyr_sources_ifdef(CONFIG_IPM_CONSOLE ipm_console.c)
 zephyr_sources_ifdef(CONFIG_UART_MCUMGR uart_mcumgr.c)
 zephyr_sources_ifdef(CONFIG_UART_PIPE uart_pipe.c)
 zephyr_sources_ifdef(CONFIG_XTENSA_SIM_CONSOLE xtensa_sim_console.c)

drivers/console/Kconfig

@@ -168,6 +168,36 @@ config IPM_CONSOLE_STACK_SIZE
 	  thread to print out incoming messages from the remote CPU. Specify the
 	  stack size for these threads here.
 
+config IPM_CONSOLE
+	bool "Inter-processor Mailbox console"
+	depends on IPM
+	select CONSOLE_HAS_DRIVER
+	help
+	  Enable console over Inter-processor Mailbox.
+
+config IPM_CONSOLE_ON_DEV_NAME
+	string "IPM device name used by console"
+	default "IPM_0"
+	depends on IPM_CONSOLE
+	help
+	  IPM device name used by IPM console driver.
+
+config IPM_CONSOLE_LINE_BUF_LEN
+	int "IPM console line buffer length"
+	default 128
+	depends on IPM_CONSOLE
+	help
+	  IPM console line buffer length specify amount of the buffer
+	  where characters are stored before sending the whole line.
+
+config IPM_CONSOLE_IMMEDIATE
+	bool "Immediate logging over IPM"
+	default y
+	depends on IPM_CONSOLE
+	help
+	  When enabled console output is processed in the context of the call. Output
+	  is blocked until read by the Host.
+
 config UART_PIPE
 	bool "Enable pipe UART driver"
 	select UART_INTERRUPT_DRIVEN

drivers/console/ipm_console.c

@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2020 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <kernel.h>
+#include <device.h>
+#include <init.h>
+#include <drivers/ipm.h>
+
+#include <logging/log.h>
+LOG_MODULE_REGISTER(ipm_console, CONFIG_IPM_LOG_LEVEL);
+
+struct device *ipm_dev;
+
+static int console_out(int c)
+{
+	static char buf[CONFIG_IPM_CONSOLE_LINE_BUF_LEN];
+	static size_t len;
+	int ret;
+
+	if (c != '\n' && len < sizeof(buf)) {
+		buf[len++] = c;
+		return c;
+	}
+
+	ret = ipm_send(ipm_dev, 1, len, buf, len);
+	if (ret) {
+		LOG_ERR("Error sending character %c over IPM, ret %d", c, ret);
+	}
+
+	memset(buf, 0, sizeof(buf));
+	len = 0;
+
+	/* After buffer is full start a new one */
+	if (c != '\n') {
+		buf[len++] = c;
+	}
+
+	return c;
+}
+
+#if defined(CONFIG_STDOUT_CONSOLE)
+extern void __stdout_hook_install(int (*hook)(int));
+#else
+#define __stdout_hook_install(x)	\
+	do {    /* nothing */		\
+	} while ((0))
+#endif
+
+#if defined(CONFIG_PRINTK)
+extern void __printk_hook_install(int (*fn)(int));
+#else
+#define __printk_hook_install(x)	\
+	do {    /* nothing */		\
+	} while ((0))
+#endif
+
+/* Install printk/stdout hooks */
+static void ipm_console_hook_install(void)
+{
+	__stdout_hook_install(console_out);
+	__printk_hook_install(console_out);
+}
+
+static int ipm_console_init(struct device *dev)
+{
+	ARG_UNUSED(dev);
+
+	LOG_DBG("IPM console initialization");
+
+	ipm_dev = device_get_binding(CONFIG_IPM_CONSOLE_ON_DEV_NAME);
+	if (!ipm_dev) {
+		LOG_ERR("Cannot get %s", CONFIG_IPM_CONSOLE_ON_DEV_NAME);
+		return -ENODEV;
+	}
+
+	if (ipm_max_id_val_get(ipm_dev) < CONFIG_IPM_CONSOLE_LINE_BUF_LEN) {
+		LOG_ERR("IPM driver does not support buffer length %d",
+			CONFIG_IPM_CONSOLE_LINE_BUF_LEN);
+		return -ENOTSUP;
+	}
+
+	ipm_console_hook_install();
+
+	return 0;
+}
+
+/* Need to be initialized after IPM */
+SYS_INIT(ipm_console_init, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT);