[PATCH 09/13] nvmem: add command to list nvmem devices

[Ahmad Fatoum]

When doing development around nvmem devices, it can be useful to list
which ones exist. Add a command to facilitate this. It can be extended
in future as the need arises (e.g.export cells into the environment?).

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 commands/Kconfig               |  7 +++++++
 commands/Makefile              |  1 +
 commands/nvmem.c               | 24 ++++++++++++++++++++++++
 drivers/nvmem/core.c           |  9 +++++++++
 include/linux/nvmem-consumer.h |  2 ++
 5 files changed, 43 insertions(+)
 create mode 100644 commands/nvmem.c

diff --git a/commands/Kconfig b/commands/Kconfig
index 5ae3cb3dd145..7bb36d6e417e 100644
--- a/commands/Kconfig
+++ b/commands/Kconfig
@@ -206,6 +206,13 @@ config CMD_REGULATOR
 	  the regulator command lists the currently registered regulators and
 	  their current state.
 
+config CMD_NVMEM
+	bool
+	depends on NVMEM
+	prompt "nvmem command"
+	help
+	  the nvmem command lists the currently registered nvmem devices.
+
 config CMD_LSPCI
 	bool
 	depends on PCI
diff --git a/commands/Makefile b/commands/Makefile
index 4b45d266fd56..ba5ea19eb202 100644
--- a/commands/Makefile
+++ b/commands/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_CMD_SAVEENV)	+= saveenv.o
 obj-$(CONFIG_CMD_LOADENV)	+= loadenv.o
 obj-$(CONFIG_CMD_NAND)		+= nand.o
 obj-$(CONFIG_CMD_NANDTEST)	+= nandtest.o
+obj-$(CONFIG_CMD_NVMEM)		+= nvmem.o
 obj-$(CONFIG_CMD_MEMTEST)	+= memtest.o
 obj-$(CONFIG_CMD_MEMTESTER)	+= memtester/
 obj-$(CONFIG_CMD_TRUE)		+= true.o
diff --git a/commands/nvmem.c b/commands/nvmem.c
new file mode 100644
index 000000000000..a0e3d092e3cf
--- /dev/null
+++ b/commands/nvmem.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+// SPDX-FileCopyrightText: © 2021 Ahmad Fatoum, Pengutronix
+
+#include <common.h>
+#include <command.h>
+#include <linux/nvmem-consumer.h>
+
+static int do_nvmem(int argc, char *argv[])
+{
+	nvmem_devices_print();
+
+	return 0;
+}
+
+BAREBOX_CMD_HELP_START(nvmem)
+BAREBOX_CMD_HELP_TEXT("Usage: nvmem")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(nvmem)
+	.cmd		= do_nvmem,
+	BAREBOX_CMD_DESC("list nvmem devices")
+	BAREBOX_CMD_GROUP(CMD_GRP_HWMANIP)
+	BAREBOX_CMD_HELP(cmd_nvmem_help)
+BAREBOX_CMD_END
diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index c060e627db4f..ae9c965c25e2 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -49,6 +49,15 @@ struct nvmem_cell {
 static LIST_HEAD(nvmem_cells);
 static LIST_HEAD(nvmem_devs);
 
+void nvmem_devices_print(void)
+{
+	struct nvmem_device *dev;
+
+	list_for_each_entry(dev, &nvmem_devs, node) {
+		printf("%s\n", dev_name(&dev->dev));
+	}
+}
+
 static ssize_t nvmem_cdev_read(struct cdev *cdev, void *buf, size_t count,
 			       loff_t offset, unsigned long flags)
 {
diff --git a/include/linux/nvmem-consumer.h b/include/linux/nvmem-consumer.h
index 5f44cf00cdff..b979f23372a6 100644
--- a/include/linux/nvmem-consumer.h
+++ b/include/linux/nvmem-consumer.h
@@ -49,6 +49,8 @@ ssize_t nvmem_device_cell_read(struct nvmem_device *nvmem,
 int nvmem_device_cell_write(struct nvmem_device *nvmem,
 			    struct nvmem_cell_info *info, void *buf);
 
+void nvmem_devices_print(void);
+
 #else
 
 static inline struct nvmem_cell *nvmem_cell_get(struct device_d *dev,
-- 
2.29.2