On Fri, Aug 04, 2023 at 05:23:36PM +0530, Saranya Gopal wrote:
> Add support for UCSI commands through the following debugfs:
> # /sys/kernel/debug/usb/ucsi/$UCSI_DEVICE/command
> # /sys/kernel/debug/usb/ucsi/$UCSI_DEVICE/response
>
> Eg: To execute UCSI GetCapabilities:
> # echo 0x6 > /sys/kernel/debug/usb/ucsi/<ucsi device>/command
> Then read the result,
> # cat /sys/kernel/debug/usb/ucsi/<ucsi device>/response
> 0x02000320000000020000ff0400000445
>
> UCSI command will be written into the command file and the
> response for the command can be viewed under the response file.
>
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Signed-off-by: Saranya Gopal <saranya.gopal@xxxxxxxxx>
> Co-developed-by: Rajaram Regupathy <rajaram.regupathy@xxxxxxxxx>
> Signed-off-by: Rajaram Regupathy <rajaram.regupathy@xxxxxxxxx>
> ---
> drivers/usb/typec/ucsi/Kconfig | 1 +
> drivers/usb/typec/ucsi/Makefile | 2 +
> drivers/usb/typec/ucsi/debugfs.c | 102 +++++++++++++++++++++++++++++++
> drivers/usb/typec/ucsi/debugfs.h | 47 ++++++++++++++
> drivers/usb/typec/ucsi/ucsi.c | 15 +++++
> drivers/usb/typec/ucsi/ucsi.h | 2 +
> 6 files changed, 169 insertions(+)
> create mode 100644 drivers/usb/typec/ucsi/debugfs.c
> create mode 100644 drivers/usb/typec/ucsi/debugfs.h
>
> diff --git a/drivers/usb/typec/ucsi/Kconfig b/drivers/usb/typec/ucsi/Kconfig
> index b3bb0191987e..bdcb1764cfae 100644
> --- a/drivers/usb/typec/ucsi/Kconfig
> +++ b/drivers/usb/typec/ucsi/Kconfig
> @@ -4,6 +4,7 @@ config TYPEC_UCSI
> tristate "USB Type-C Connector System Software Interface driver"
> depends on !CPU_BIG_ENDIAN
> depends on USB_ROLE_SWITCH || !USB_ROLE_SWITCH
> + select USB_COMMON if DEBUG_FS
> help
> USB Type-C Connector System Software Interface (UCSI) is a
> specification for an interface that allows the operating system to
> diff --git a/drivers/usb/typec/ucsi/Makefile b/drivers/usb/typec/ucsi/Makefile
> index 77f09e136956..b4679f94696b 100644
> --- a/drivers/usb/typec/ucsi/Makefile
> +++ b/drivers/usb/typec/ucsi/Makefile
> @@ -5,6 +5,8 @@ obj-$(CONFIG_TYPEC_UCSI) += typec_ucsi.o
>
> typec_ucsi-y := ucsi.o
>
> +typec_ucsi-$(CONFIG_DEBUG_FS) += debugfs.o
> +
> typec_ucsi-$(CONFIG_TRACING) += trace.o
>
> ifneq ($(CONFIG_POWER_SUPPLY),)
> diff --git a/drivers/usb/typec/ucsi/debugfs.c b/drivers/usb/typec/ucsi/debugfs.c
> new file mode 100644
> index 000000000000..2bb74ff007fc
> --- /dev/null
> +++ b/drivers/usb/typec/ucsi/debugfs.c
> @@ -0,0 +1,102 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * UCSI debugfs interface
> + *
> + * Copyright (C) 2023 Intel Corporation
> + *
> + * Authors: Rajaram Regupathy <rajaram.regupathy@xxxxxxxxx>
> + * Gopal Saranya <saranya.gopal@xxxxxxxxx>
> + */
> +#include <linux/debugfs.h>
> +#include <linux/slab.h>
> +#include <linux/string.h>
> +#include <linux/types.h>
> +#include <linux/usb.h>
> +
> +#include <asm/errno.h>
> +
> +#include "debugfs.h"
> +#include "ucsi.h"
> +
> +static struct dentry *ucsi_debugfs_root;
> +
> +static int ucsi_cmd(void *data, u64 val)
> +{
> + struct ucsi *ucsi = data;
> + int ret;
> +
> + memset(&ucsi->debugfs->response, 0, sizeof(ucsi->debugfs->response));
> + ucsi->debugfs->status = 0;
> +
> + switch (UCSI_COMMAND(val)) {
> + case UCSI_SET_UOM:
> + case UCSI_SET_UOR:
> + case UCSI_SET_PDR:
> + case UCSI_CONNECTOR_RESET:
> + ret = ucsi_send_command(ucsi, val, NULL, 0);
> + break;
> + case UCSI_GET_CAPABILITY:
> + case UCSI_GET_CONNECTOR_CAPABILITY:
> + case UCSI_GET_ALTERNATE_MODES:
> + case UCSI_GET_CURRENT_CAM:
> + case UCSI_GET_PDOS:
> + case UCSI_GET_CABLE_PROPERTY:
> + case UCSI_GET_CONNECTOR_STATUS:
> + ret = ucsi_send_command(ucsi, val,
> + &ucsi->debugfs->response,
> + sizeof(ucsi->debugfs->response));
> + break;
> + default:
> + ret = -EOPNOTSUPP;
> + }
> +
> + if (ret < 0) {
> + ucsi->debugfs->status = ret;
> + return ret;
> + }
> +
> + return 0;
> +}
> +DEFINE_DEBUGFS_ATTRIBUTE(ucsi_cmd_fops, NULL, ucsi_cmd, "0x%llx\n");
> +
> +static int ucsi_resp_show(struct seq_file *s, void *not_used)
> +{
> + struct ucsi *ucsi = s->private;
> +
> + if (ucsi->debugfs->status)
> + return ucsi->debugfs->status;
> +
> + seq_printf(s, "0x%016llx%016llx\n", ucsi->debugfs->response.high,
> + ucsi->debugfs->response.low);
> + return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(ucsi_resp);
> +
> +int ucsi_debugfs_register(struct ucsi *ucsi)
> +{
> + ucsi->debugfs = kzalloc(sizeof(*ucsi->debugfs), GFP_KERNEL);
> + if (!ucsi->debugfs)
> + return -ENOMEM;
It's good to catch this, but it doesn't matter if it happens, just
return, no need to do anything different if this fails.
> +
> + ucsi->debugfs->dentry = debugfs_create_dir(dev_name(ucsi->dev), ucsi_debugfs_root);
> + debugfs_create_file("command", 0200, ucsi->debugfs->dentry, ucsi, &ucsi_cmd_fops);
> + debugfs_create_file("response", 0400, ucsi->debugfs->dentry, ucsi, &ucsi_resp_fops);
> + return 0;
> +}
> +
> +void ucsi_debugfs_unregister(struct ucsi *ucsi)
> +{
> + debugfs_remove_recursive(ucsi->debugfs->dentry);
> + kfree(ucsi->debugfs);
> +}
> +
> +int ucsi_debugfs_init(void)
> +{
> + ucsi_debugfs_root = debugfs_create_dir("ucsi", usb_debug_root);
> + return 0;
This can't fail, so no need to return an int, right?
thanks,
greg k-h
