[PATCH 3/3] k10temp: Add power sensor for family 19h

[Naveen Krishna Chatradhi <nchatrad@amd.com>]

On newer Fam19h server line of AMD processors a new channel
is created to report and manage socket power limits.

This patch creates hwmon_power sensor to report current power,
power cap and max power cap of the socket.
While at it, update the k10temp documentation

Tested-by: suma hegde <suma.hegde@amd.com>
Signed-off-by: Naveen Krishna Chatradhi <nchatrad@amd.com>
Cc: Guenter Roeck <linux@roeck-us.net>
---
 Documentation/hwmon/k10temp.rst |  18 ++++++
 drivers/hwmon/k10temp.c         | 106 ++++++++++++++++++++++++++++++++
 2 files changed, 124 insertions(+)

diff --git a/Documentation/hwmon/k10temp.rst b/Documentation/hwmon/k10temp.rst
index 91b99adc6c48..d5a78a7b6ca5 100644
--- a/Documentation/hwmon/k10temp.rst
+++ b/Documentation/hwmon/k10temp.rst
@@ -132,3 +132,21 @@ On Family 17h and Family 18h CPUs, additional temperature sensors may report
 Core Complex Die (CCD) temperatures. Up to 8 such temperatures are reported
 as temp{3..10}_input, labeled Tccd{1..8}. Actual support depends on the CPU
 variant.
+
+On Family 19h server line of CPUs, additionally driver may report socket
+current power consumption with power cap and power cap max. This requires the
+HSMP support exported in the amd_nb module.
+
+The power1_cap can be set to any value, SMU FW will limit the maximum cap to
+the value reported by power1_cap_max entry. The SMU FW may not take any action
+if the power1_cap is set to a value lesser than the minimum socket consumption.
+
+The following attributes may be reported.
+
+================ ===== ========================================================
+Name             Perm  Description
+================ ===== ========================================================
+power1_input     RO    Socket current Power consumed
+power1_cap       RW    Socket Power limit can be set between 0 and power1_cap_max
+power1_cap_max   RO    Maximum powerlimit calculated and reported by the SMU FW
+================ ===== ========================================================
diff --git a/drivers/hwmon/k10temp.c b/drivers/hwmon/k10temp.c
index 3618a924e78e..b993fdd94979 100644
--- a/drivers/hwmon/k10temp.c
+++ b/drivers/hwmon/k10temp.c
@@ -105,6 +105,9 @@ struct k10temp_data {
 	u32 show_temp;
 	bool is_zen;
 	u32 ccd_offset;
+	bool show_power;
+	char pwr_label[20];
+	u32 power_cap_max;
 };
 
 #define TCTL_BIT	0
@@ -197,10 +200,14 @@ static int k10temp_read_labels(struct device *dev,
 			       enum hwmon_sensor_types type,
 			       u32 attr, int channel, const char **str)
 {
+	struct k10temp_data *data = dev_get_drvdata(dev);
 	switch (type) {
 	case hwmon_temp:
 		*str = k10temp_temp_label[channel];
 		break;
+	case hwmon_power:
+		*str = data->pwr_label;
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -254,12 +261,43 @@ static int k10temp_read_temp(struct device *dev, u32 attr, int channel,
 	return 0;
 }
 
+static int k10temp_read_power(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct k10temp_data *data = dev_get_drvdata(dev);
+	struct hsmp_message msg = { 0 };
+	int err;
+
+	switch (attr) {
+	case hwmon_power_input:
+		msg.msg_id = HSMP_GET_SOCKET_POWER;
+		break;
+	case hwmon_power_cap:
+		msg.msg_id = HSMP_GET_SOCKET_POWER_LIMIT;
+		break;
+	case hwmon_power_cap_max:
+		/* power_cap_max does not change dynamically, hence return the cached value */
+		*val = data->power_cap_max * 1000;
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+	msg.response_sz = 1;
+	err = hsmp_send_message(amd_pci_dev_to_node_id(data->pdev), &msg);
+	if (!err)
+		/* power metric is reported in micro watts. hence multiply by 1000 */
+		*val = msg.response[0] * 1000;
+
+	return err;
+}
+
 static int k10temp_read(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long *val)
 {
 	switch (type) {
 	case hwmon_temp:
 		return k10temp_read_temp(dev, attr, channel, val);
+	case hwmon_power:
+		return k10temp_read_power(dev, attr, channel, val);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -308,12 +346,45 @@ static umode_t k10temp_is_visible(const void *_data,
 			return 0;
 		}
 		break;
+	case hwmon_power:
+		switch (attr) {
+		case hwmon_power_input:
+		case hwmon_power_cap_max:
+		case hwmon_power_label:
+			/* Show power attributes only if show_power is available */
+			if (data->show_power)
+				break;
+			return 0;
+		case hwmon_power_cap:
+			if (data->show_power)
+				return 0644;
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
 	default:
 		return 0;
 	}
 	return 0444;
 }
 
+static int k10temp_write(struct device *dev, enum hwmon_sensor_types type,
+			 u32 attr, int channel, long val)
+{
+	struct hsmp_message msg = { 0 };
+	struct k10temp_data *data = dev_get_drvdata(dev);
+
+	if (type == hwmon_power && attr == hwmon_power_cap) {
+		msg.response_sz = 1;
+		msg.num_args	= 1;
+		msg.msg_id	= HSMP_SET_SOCKET_POWER_LIMIT;
+		msg.args[0]	= val / 1000;
+		return hsmp_send_message(amd_pci_dev_to_node_id(data->pdev), &msg);
+	}
+	return -EOPNOTSUPP;
+}
+
 static bool has_erratum_319(struct pci_dev *pdev)
 {
 	u32 pkg_type, reg_dram_cfg;
@@ -362,6 +433,9 @@ static const struct hwmon_channel_info *k10temp_info[] = {
 			   HWMON_T_INPUT | HWMON_T_LABEL,
 			   HWMON_T_INPUT | HWMON_T_LABEL,
 			   HWMON_T_INPUT | HWMON_T_LABEL),
+	HWMON_CHANNEL_INFO(power,
+			   HWMON_P_INPUT | HWMON_P_LABEL |
+			   HWMON_P_CAP | HWMON_P_CAP_MAX),
 	NULL
 };
 
@@ -369,6 +443,7 @@ static const struct hwmon_ops k10temp_hwmon_ops = {
 	.is_visible = k10temp_is_visible,
 	.read = k10temp_read,
 	.read_string = k10temp_read_labels,
+	.write = k10temp_write,
 };
 
 static const struct hwmon_chip_info k10temp_chip_info = {
@@ -390,6 +465,32 @@ static void k10temp_get_ccd_support(struct pci_dev *pdev,
 	}
 }
 
+static int k10temp_get_max_power(struct k10temp_data *data)
+{
+	int err;
+	struct hsmp_message msg = { 0 };
+
+	msg.msg_id = HSMP_GET_SOCKET_POWER_LIMIT_MAX;
+	msg.response_sz = 1;
+	err = hsmp_send_message(amd_pci_dev_to_node_id(data->pdev), &msg);
+	if (!err)
+		data->power_cap_max = msg.response[0];
+	return err;
+}
+
+static void check_power_support(struct k10temp_data *data)
+{
+	/* HSMP support is required to obtain power metrics */
+	if (!amd_nb_has_feature(AMD_NB_HSMP))
+		return;
+
+	if (k10temp_get_max_power(data))
+		return;
+
+	sprintf(data->pwr_label, "socket%d_pwr", amd_pci_dev_to_node_id(data->pdev));
+	data->show_power = true;
+}
+
 static int k10temp_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	int unreliable = has_erratum_319(pdev);
@@ -448,6 +549,11 @@ static int k10temp_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 		switch (boot_cpu_data.x86_model) {
 		case 0x0 ... 0x1:	/* Zen3 SP3/TR */
+		case 0x30 ... 0x31:
+			check_power_support(data);
+			data->ccd_offset = 0x154;
+			k10temp_get_ccd_support(pdev, data, 8);
+			break;
 		case 0x21:		/* Zen3 Ryzen Desktop */
 		case 0x50 ... 0x5f:	/* Green Sardine */
 			data->ccd_offset = 0x154;
-- 
2.17.1