[PATCH v8 03/10] misc: amd-sbi: Move hwmon device sensor as separate entity

Akshay Gupta
2025-04-11T13:32:00Z

- Move hwmon device sensor to misc as only power is reported through
hwmon sensor.

Reviewed-by: Naveen Krishna Chatradhi <naveenkrishna.chatradhi@amd.com>
Signed-off-by: Akshay Gupta <akshay.gupta@amd.com>
---
Changes since v7:
- Address Arnd review comment, adding new Kconfig symbol for hwmon enablement

Changes since v6:
- Fix "Missing a blank line after declarations" warning

Changes since v5:
- Patch rebased

Changes since v4:
New patch: Patch split from v4 patch 1/9
- Update Copyright year to 2025

drivers/misc/amd-sbi/Kconfig | 10 ++-
drivers/misc/amd-sbi/Makefile | 3 +-
drivers/misc/amd-sbi/rmi-core.h | 8 ++
drivers/misc/amd-sbi/rmi-hwmon.c | 121 +++++++++++++++++++++++++++++++
drivers/misc/amd-sbi/rmi-i2c.c | 104 +-------------------------
5 files changed, 142 insertions(+), 104 deletions(-)
create mode 100644 drivers/misc/amd-sbi/rmi-hwmon.c

diff --git a/drivers/misc/amd-sbi/Kconfig b/drivers/misc/amd-sbi/Kconfig
index 0c8981f97f25..4840831c84ca 100644
--- a/drivers/misc/amd-sbi/Kconfig
+++ b/drivers/misc/amd-sbi/Kconfig
@@ -2,9 +2,17 @@
config AMD_SBRMI_I2C
tristate "AMD side band RMI support"
depends on I2C
- depends on HWMON
help
Side band RMI over I2C support for AMD out of band management.

This driver can also be built as a module. If so, the module will
be called sbrmi-i2c.
+
+config AMD_SBRMI_HWMON
+ bool "SBRMI hardware monitoring"
+ depends on AMD_SBRMI_I2C && HWMON
+ depends on !(AMD_SBRMI_I2C=y && HWMON=m)
+ help
+ This provides support for RMI device hardware monitoring. If enabled,
+ a hardware monitoring device will be created for each socket in
+ the system.
diff --git a/drivers/misc/amd-sbi/Makefile b/drivers/misc/amd-sbi/Makefile
index 7cd8e0a1aa5d..38eaaa651fd9 100644
--- a/drivers/misc/amd-sbi/Makefile
+++ b/drivers/misc/amd-sbi/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
-sbrmi-i2c-objs := rmi-i2c.o rmi-core.o
+sbrmi-i2c-objs += rmi-i2c.o rmi-core.o
+sbrmi-i2c-$(CONFIG_AMD_SBRMI_HWMON) += rmi-hwmon.o
obj-$(CONFIG_AMD_SBRMI_I2C) += sbrmi-i2c.o
diff --git a/drivers/misc/amd-sbi/rmi-core.h b/drivers/misc/amd-sbi/rmi-core.h
index 8e30a43ec714..977ee05af6a6 100644
--- a/drivers/misc/amd-sbi/rmi-core.h
+++ b/drivers/misc/amd-sbi/rmi-core.h
@@ -60,4 +60,12 @@ struct sbrmi_mailbox_msg {
};

int rmi_mailbox_xfer(struct sbrmi_data *data, struct sbrmi_mailbox_msg *msg);
+#ifdef CONFIG_AMD_SBRMI_HWMON
+int create_hwmon_sensor_device(struct device *dev, struct sbrmi_data *data);
+#else
+static inline int create_hwmon_sensor_device(struct device *dev, struct sbrmi_data *data)
+{
+ return 0;
+}
+#endif
#endif /*_SBRMI_CORE_H_*/
diff --git a/drivers/misc/amd-sbi/rmi-hwmon.c b/drivers/misc/amd-sbi/rmi-hwmon.c
new file mode 100644
index 000000000000..720e800db1f0
--- /dev/null
+++ b/drivers/misc/amd-sbi/rmi-hwmon.c
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * rmi-hwmon.c - hwmon sensor support for side band RMI
+ *
+ * Copyright (C) 2025 Advanced Micro Devices, Inc.
+ */
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include "rmi-core.h"
+
+/* Do not allow setting negative power limit */
+#define SBRMI_PWR_MIN 0
+
+static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long *val)
+{
+ struct sbrmi_data *data = dev_get_drvdata(dev);
+ struct sbrmi_mailbox_msg msg = { 0 };
+ int ret;
+
+ if (!data)
+ return -ENODEV;
+
+ if (type != hwmon_power)
+ return -EINVAL;
+
+ msg.read = true;
+ switch (attr) {
+ case hwmon_power_input:
+ msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION;
+ ret = rmi_mailbox_xfer(data, &msg);
+ break;
+ case hwmon_power_cap:
+ msg.cmd = SBRMI_READ_PKG_PWR_LIMIT;
+ ret = rmi_mailbox_xfer(data, &msg);
+ break;
+ case hwmon_power_cap_max:
+ msg.data_out = data->pwr_limit_max;
+ ret = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+ if (ret < 0)
+ return ret;
+ /* hwmon power attributes are in microWatt */
+ *val = (long)msg.data_out * 1000;
+ return ret;
+}
+
+static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type,
+ u32 attr, int channel, long val)
+{
+ struct sbrmi_data *data = dev_get_drvdata(dev);
+ struct sbrmi_mailbox_msg msg = { 0 };
+
+ if (!data)
+ return -ENODEV;
+
+ if (type != hwmon_power && attr != hwmon_power_cap)
+ return -EINVAL;
+ /*
+ * hwmon power attributes are in microWatt
+ * mailbox read/write is in mWatt
+ */
+ val /= 1000;
+
+ val = clamp_val(val, SBRMI_PWR_MIN, data->pwr_limit_max);
+
+ msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT;
+ msg.data_in = val;
+ msg.read = false;
+
+ return rmi_mailbox_xfer(data, &msg);
+}
+
+static umode_t sbrmi_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ switch (type) {
+ case hwmon_power:
+ switch (attr) {
+ case hwmon_power_input:
+ case hwmon_power_cap_max:
+ return 0444;
+ case hwmon_power_cap:
+ return 0644;
+ }
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+static const struct hwmon_channel_info * const sbrmi_info[] = {
+ HWMON_CHANNEL_INFO(power,
+ HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX),
+ NULL
+};
+
+static const struct hwmon_ops sbrmi_hwmon_ops = {
+ .is_visible = sbrmi_is_visible,
+ .read = sbrmi_read,
+ .write = sbrmi_write,
+};
+
+static const struct hwmon_chip_info sbrmi_chip_info = {
+ .ops = &sbrmi_hwmon_ops,
+ .info = sbrmi_info,
+};
+
+int create_hwmon_sensor_device(struct device *dev, struct sbrmi_data *data)
+{
+ struct device *hwmon_dev;
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, "sbrmi", data,
+ &sbrmi_chip_info, NULL);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
diff --git a/drivers/misc/amd-sbi/rmi-i2c.c b/drivers/misc/amd-sbi/rmi-i2c.c
index 6412f00eb381..9ad4c8093399 100644
--- a/drivers/misc/amd-sbi/rmi-i2c.c
+++ b/drivers/misc/amd-sbi/rmi-i2c.c
@@ -8,7 +8,6 @@

#include <linux/delay.h>
#include <linux/err.h>
-#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
@@ -16,9 +15,6 @@
#include <linux/of.h>
#include "rmi-core.h"

-/* Do not allow setting negative power limit */
-#define SBRMI_PWR_MIN 0
-
static int sbrmi_enable_alert(struct i2c_client *client)
{
int ctrl;
@@ -40,100 +36,6 @@ static int sbrmi_enable_alert(struct i2c_client *client)
return 0;
}

-static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type,
- u32 attr, int channel, long *val)
-{
- struct sbrmi_data *data = dev_get_drvdata(dev);
- struct sbrmi_mailbox_msg msg = { 0 };
- int ret;
-
- if (type != hwmon_power)
- return -EINVAL;
-
- msg.read = true;
- switch (attr) {
- case hwmon_power_input:
- msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION;
- ret = rmi_mailbox_xfer(data, &msg);
- break;
- case hwmon_power_cap:
- msg.cmd = SBRMI_READ_PKG_PWR_LIMIT;
- ret = rmi_mailbox_xfer(data, &msg);
- break;
- case hwmon_power_cap_max:
- msg.data_out = data->pwr_limit_max;
- ret = 0;
- break;
- default:
- return -EINVAL;
- }
- if (ret < 0)
- return ret;
- /* hwmon power attributes are in microWatt */
- *val = (long)msg.data_out * 1000;
- return ret;
-}
-
-static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type,
- u32 attr, int channel, long val)
-{
- struct sbrmi_data *data = dev_get_drvdata(dev);
- struct sbrmi_mailbox_msg msg = { 0 };
-
- if (type != hwmon_power && attr != hwmon_power_cap)
- return -EINVAL;
- /*
- * hwmon power attributes are in microWatt
- * mailbox read/write is in mWatt
- */
- val /= 1000;
-
- val = clamp_val(val, SBRMI_PWR_MIN, data->pwr_limit_max);
-
- msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT;
- msg.data_in = val;
- msg.read = false;
-
- return rmi_mailbox_xfer(data, &msg);
-}
-
-static umode_t sbrmi_is_visible(const void *data,
- enum hwmon_sensor_types type,
- u32 attr, int channel)
-{
- switch (type) {
- case hwmon_power:
- switch (attr) {
- case hwmon_power_input:
- case hwmon_power_cap_max:
- return 0444;
- case hwmon_power_cap:
- return 0644;
- }
- break;
- default:
- break;
- }
- return 0;
-}
-
-static const struct hwmon_channel_info * const sbrmi_info[] = {
- HWMON_CHANNEL_INFO(power,
- HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX),
- NULL
-};
-
-static const struct hwmon_ops sbrmi_hwmon_ops = {
- .is_visible = sbrmi_is_visible,
- .read = sbrmi_read,
- .write = sbrmi_write,
-};
-
-static const struct hwmon_chip_info sbrmi_chip_info = {
- .ops = &sbrmi_hwmon_ops,
- .info = sbrmi_info,
-};
-
static int sbrmi_get_max_pwr_limit(struct sbrmi_data *data)
{
struct sbrmi_mailbox_msg msg = { 0 };
@@ -152,7 +54,6 @@ static int sbrmi_get_max_pwr_limit(struct sbrmi_data *data)
static int sbrmi_i2c_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
- struct device *hwmon_dev;
struct sbrmi_data *data;
int ret;

@@ -173,9 +74,8 @@ static int sbrmi_i2c_probe(struct i2c_client *client)
if (ret < 0)
return ret;

- hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
- &sbrmi_chip_info, NULL);
- return PTR_ERR_OR_ZERO(hwmon_dev);
+ dev_set_drvdata(dev, data);
+ return create_hwmon_sensor_device(dev, data);
}

static const struct i2c_device_id sbrmi_id[] = {
--
2.25.1