mlxsw: core: Set different thermal polling time based on bus frequency capability

Add low frequency bus capability in order to allow core functionality
separation based on bus type. Driver could run over PCIe, which is
considered as high frequency bus or I2C, which is considered as low
frequency bus. In the last case time setting, for example, for thermal
polling interval, should be increased.

Use different thermal monitoring based on bus type. For I2C bus time is
set to 20 seconds, while for PCIe 1 second polling interval is used.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlxsw/core.h

@@ -344,6 +344,7 @@ struct mlxsw_bus_info {
 	struct mlxsw_fw_rev fw_rev;
 	u8 vsd[MLXSW_CMD_BOARDINFO_VSD_LEN];
 	u8 psid[MLXSW_CMD_BOARDINFO_PSID_LEN];
+	u8 low_frequency;
 };
 
 struct mlxsw_hwmon;

drivers/net/ethernet/mellanox/mlxsw/core_thermal.c

@@ -13,6 +13,7 @@
 #include "core.h"
 
 #define MLXSW_THERMAL_POLL_INT	1000	/* ms */
+#define MLXSW_THERMAL_SLOW_POLL_INT	20000	/* ms */
 #define MLXSW_THERMAL_MAX_TEMP	110000	/* 110C */
 #define MLXSW_THERMAL_MAX_STATE	10
 #define MLXSW_THERMAL_MAX_DUTY	255
@@ -76,6 +77,7 @@ struct mlxsw_thermal {
 	struct mlxsw_core *core;
 	const struct mlxsw_bus_info *bus_info;
 	struct thermal_zone_device *tzdev;
+	int polling_delay;
 	struct thermal_cooling_device *cdevs[MLXSW_MFCR_PWMS_MAX];
 	u8 cooling_levels[MLXSW_THERMAL_MAX_STATE + 1];
 	struct mlxsw_thermal_trip trips[MLXSW_THERMAL_NUM_TRIPS];
@@ -172,7 +174,7 @@ static int mlxsw_thermal_set_mode(struct thermal_zone_device *tzdev,
 	mutex_lock(&tzdev->lock);
 
 	if (mode == THERMAL_DEVICE_ENABLED)
-		tzdev->polling_delay = MLXSW_THERMAL_POLL_INT;
+		tzdev->polling_delay = thermal->polling_delay;
 	else
 		tzdev->polling_delay = 0;
 
@@ -423,13 +425,17 @@ int mlxsw_thermal_init(struct mlxsw_core *core,
 		thermal->cooling_levels[i] = max(MLXSW_THERMAL_SPEED_MIN_LEVEL,
 						 i);
 
+	thermal->polling_delay = bus_info->low_frequency ?
+				 MLXSW_THERMAL_SLOW_POLL_INT :
+				 MLXSW_THERMAL_POLL_INT;
+
 	thermal->tzdev = thermal_zone_device_register("mlxsw",
 						      MLXSW_THERMAL_NUM_TRIPS,
 						      MLXSW_THERMAL_TRIP_MASK,
 						      thermal,
 						      &mlxsw_thermal_ops,
 						      NULL, 0,
-						      MLXSW_THERMAL_POLL_INT);
+						      thermal->polling_delay);
 	if (IS_ERR(thermal->tzdev)) {
 		err = PTR_ERR(thermal->tzdev);
 		dev_err(dev, "Failed to register thermal zone\n");

drivers/net/ethernet/mellanox/mlxsw/i2c.c

@@ -503,6 +503,7 @@ static int mlxsw_i2c_probe(struct i2c_client *client,
 	mlxsw_i2c->bus_info.device_kind = id->name;
 	mlxsw_i2c->bus_info.device_name = client->name;
 	mlxsw_i2c->bus_info.dev = &client->dev;
+	mlxsw_i2c->bus_info.low_frequency = true;
 	mlxsw_i2c->dev = &client->dev;
 
 	err = mlxsw_core_bus_device_register(&mlxsw_i2c->bus_info,