[PATCH v6 2/5] drivers: sysreset: Add sysreset op that can take arguments

[Varadarajan Narayanan]

Add a 'request_arg' op to struct sysreset_ops to enable sysreset drivers
to receive arguments given to the 'reset' command. Process the
request_arg() op before the usual request() op.

Reviewed-by: Casey Connolly <casey.connolly at linaro.org>
Reviewed-by: Sumit Garg <sumit.garg at oss.qualcomm.com>
Signed-off-by: Varadarajan Narayanan <varadarajan.narayanan at oss.qualcomm.com>
---
v6: Wrap this functionality inside CONFIG_SYSRESET_CMD_RESET_ARGS
---
 drivers/sysreset/Kconfig           |  8 +++++++
 drivers/sysreset/sysreset-uclass.c | 37 ++++++++++++++++++++++++++++++
 include/sysreset.h                 | 18 +++++++++++++++
 3 files changed, 63 insertions(+)

diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig
index 0181f6cd581..6fb0ca81dc6 100644
--- a/drivers/sysreset/Kconfig
+++ b/drivers/sysreset/Kconfig
@@ -49,6 +49,14 @@ config SYSRESET_CMD_RESET
 	help
 	  Enable sysreset implementation of the reset command.
 
+config SYSRESET_CMD_RESET_ARGS
+	bool "Enable reset command to take arguments"
+	help
+	  Pass on the arguments received by the 'reset' command to the
+	  sysreset driver(s). The sysreset driver(s) may make use of the
+	  additional arguments for implementing arch/board specific
+	  functionality.
+
 if CMD_POWEROFF
 
 config SYSRESET_CMD_POWEROFF
diff --git a/drivers/sysreset/sysreset-uclass.c b/drivers/sysreset/sysreset-uclass.c
index 536ac727142..f25e09e9cd0 100644
--- a/drivers/sysreset/sysreset-uclass.c
+++ b/drivers/sysreset/sysreset-uclass.c
@@ -32,6 +32,18 @@ int sysreset_request(struct udevice *dev, enum sysreset_t type)
 	return ops->request(dev, type);
 }
 
+#if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_ARGS)
+int sysreset_request_arg(struct udevice *dev, int argc, char * const argv[])
+{
+	struct sysreset_ops *ops = sysreset_get_ops(dev);
+
+	if (!ops->request_arg)
+		return -ENOSYS;
+
+	return ops->request_arg(dev, argc, argv);
+}
+#endif /* CONFIG_SYSRESET_CMD_RESET_ARGS */
+
 int sysreset_get_status(struct udevice *dev, char *buf, int size)
 {
 	struct sysreset_ops *ops = sysreset_get_ops(dev);
@@ -71,6 +83,26 @@ int sysreset_walk(enum sysreset_t type)
 	return ret;
 }
 
+#if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_ARGS)
+int sysreset_walk_arg(int argc, char * const argv[])
+{
+	struct udevice *dev;
+	int ret = -ENOSYS;
+
+	while (ret != -EINPROGRESS && ret != -EPROTONOSUPPORT) {
+		for (uclass_first_device(UCLASS_SYSRESET, &dev);
+		     dev;
+		     uclass_next_device(&dev)) {
+			ret = sysreset_request_arg(dev, argc, argv);
+			if (ret == -EINPROGRESS || ret == -EPROTONOSUPPORT)
+				break;
+		}
+	}
+
+	return ret;
+}
+#endif /* CONFIG_SYSRESET_CMD_RESET_ARGS */
+
 int sysreset_get_last_walk(void)
 {
 	struct udevice *dev;
@@ -132,6 +164,11 @@ int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	printf("resetting ...\n");
 	mdelay(100);
 
+#if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET_ARGS)
+	if (argc > 1 && sysreset_walk_arg(argc, argv) == -EINPROGRESS)
+		return 0;
+#endif
+
 	sysreset_walk_halt(reset_type);
 
 	return 0;
diff --git a/include/sysreset.h b/include/sysreset.h
index ff20abdeed3..d1cc9ebc542 100644
--- a/include/sysreset.h
+++ b/include/sysreset.h
@@ -43,6 +43,24 @@ struct sysreset_ops {
 	 * (in which case this method will not actually return)
 	 */
 	int (*request)(struct udevice *dev, enum sysreset_t type);
+
+	/**
+	 * @request_arg: Reset handler implementations that might need to process
+	 *		 arguments given to the 'reset' command.
+	 *
+	 * Note that this function may return before the reset takes effect.
+	 *
+	 * @dev:	Device to be used for system reset
+	 * @argc:	No. of items in @argv
+	 * @argv:	Arguments given to 'reset' command
+	 * Return:
+	 * -EINPROGRESS		if the reset has started and will complete soon
+	 * -EPROTONOSUPPORT	if not supported by this device
+	 * 0			if the reset has already happened
+	 * (in which case this method will not actually return)
+	 */
+	int (*request_arg)(struct udevice *dev, int argc, char * const argv[]);
+
 	/**
 	 * @get_status:	get printable reset status information
 	 *
-- 
2.34.1