[PATCH 3/6] hwmon: sparx5: add LAN969x fan monitoring support
Robert Marko
robert.marko at sartura.hr
Tue Oct 13 05:56:27 PDT 2026
LAN969x contains a tachometer input alongside its Sparx5-compatible
temperature sensor.
Use match data to map and initialize the additional fan controller
register region only for the LAN969x hardware-monitor compatible. Read
the optional pulses-per-revolution property from the fan child and expose
the measured speed through fan1_input.
Leave existing Sparx5 and LAN969x temperature-only device trees
unchanged.
Signed-off-by: Robert Marko <robert.marko at sartura.hr>
---
Documentation/hwmon/sparx5-temp.rst | 8 +++
drivers/hwmon/Kconfig | 7 +-
drivers/hwmon/sparx5-temp.c | 108 +++++++++++++++++++++++++---
3 files changed, 110 insertions(+), 13 deletions(-)
diff --git a/Documentation/hwmon/sparx5-temp.rst b/Documentation/hwmon/sparx5-temp.rst
index 0140809089542..1256d37e1c091 100644
--- a/Documentation/hwmon/sparx5-temp.rst
+++ b/Documentation/hwmon/sparx5-temp.rst
@@ -15,6 +15,9 @@ Supported chips:
Author: Lars Povlsen <lars.povlsen at microchip.com>
+The driver also supports the Microchip LAN969x temperature sensor and fan
+tachometer through the microchip,lan9691-hwmon compatible.
+
Description
-----------
@@ -30,4 +33,9 @@ The following attributes are supported.
======================= ========================================================
temp1_input Die temperature (in millidegree Celsius.)
+fan1_input Fan speed in RPM (LAN969x only).
======================= ========================================================
+
+The tachometer counts pulses over one-second intervals, independently of the
+PWM output. The fan child's pulses-per-revolution property specifies how many
+pulses represent one revolution; it defaults to two.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 18c682e1a4756..01ac166380905 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -649,11 +649,12 @@ config SENSORS_I5K_AMB
will be called i5k_amb.
config SENSORS_SPARX5
- tristate "Sparx5 SoC temperature sensor"
+ tristate "Sparx5 and LAN969x SoC hardware monitoring"
depends on ARCH_SPARX5 || ARCH_LAN969X || COMPILE_TEST
help
- If you say yes here you get support for temperature monitoring
- with the Microchip Sparx5 SoC.
+ If you say yes here you get support for temperature monitoring on
+ Microchip Sparx5 and LAN969x SoCs, as well as fan monitoring on
+ LAN969x SoCs.
This driver can also be built as a module. If so, the module
will be called sparx5-temp.
diff --git a/drivers/hwmon/sparx5-temp.c b/drivers/hwmon/sparx5-temp.c
index 0fd5c147f8167..922c3c33a049a 100644
--- a/drivers/hwmon/sparx5-temp.c
+++ b/drivers/hwmon/sparx5-temp.c
@@ -9,8 +9,11 @@
#include <linux/hwmon.h>
#include <linux/init.h>
#include <linux/io.h>
+#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/platform_device.h>
+#include <linux/property.h>
#define TEMP_CTRL 0
#define TEMP_CFG 4
@@ -20,9 +23,26 @@
#define TEMP_STAT_VALID BIT(12)
#define TEMP_STAT_TEMP GENMASK(11, 0)
+#define FAN_CFG 0
+#define FAN_CFG_GATE_ENA BIT(2)
+#define FAN_CFG_STAT_MODE BIT(0)
+#define FAN_PWM_FREQ 4
+#define FAN_PWM_FREQ_CYCLES GENMASK(27, 16)
+#define FAN_CNT 8
+#define FAN_CNT_DATA GENMASK(15, 0)
+
+#define FAN_TACH_INTERVAL_HZ 100000
+
+struct s5_match_data {
+ bool has_fan;
+};
+
struct s5_hwmon {
void __iomem *base;
+ void __iomem *fan;
struct clk *clk;
+ unsigned long clk_rate;
+ u32 pulses_per_revolution;
};
static void s5_temp_enable(struct s5_hwmon *hwmon)
@@ -37,6 +57,24 @@ static void s5_temp_enable(struct s5_hwmon *hwmon)
writel(val, hwmon->base + TEMP_CFG);
}
+static void s5_fan_enable(struct s5_hwmon *hwmon)
+{
+ u32 cycles, val;
+
+ cycles = DIV_ROUND_CLOSEST(hwmon->clk_rate, FAN_TACH_INTERVAL_HZ);
+ cycles = clamp_val(cycles, 1, FIELD_MAX(FAN_PWM_FREQ_CYCLES));
+
+ val = readl(hwmon->fan + FAN_PWM_FREQ);
+ val &= ~FAN_PWM_FREQ_CYCLES;
+ val |= FIELD_PREP(FAN_PWM_FREQ_CYCLES, cycles);
+ writel(val, hwmon->fan + FAN_PWM_FREQ);
+
+ /* Count all tachometer pulses over one-second intervals. */
+ val = readl(hwmon->fan + FAN_CFG);
+ val &= ~(FAN_CFG_STAT_MODE | FAN_CFG_GATE_ENA);
+ writel(val, hwmon->fan + FAN_CFG);
+}
+
static int s5_read_temp(struct s5_hwmon *hwmon, long *temp)
{
int value;
@@ -62,6 +100,17 @@ static int s5_read_temp(struct s5_hwmon *hwmon, long *temp)
return 0;
}
+static int s5_read_fan(struct s5_hwmon *hwmon, long *val)
+{
+ u32 count;
+
+ count = readl_relaxed(hwmon->fan + FAN_CNT);
+ count = FIELD_GET(FAN_CNT_DATA, count);
+ *val = count * 60 / hwmon->pulses_per_revolution;
+
+ return 0;
+}
+
static int s5_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
@@ -72,6 +121,10 @@ static int s5_read(struct device *dev, enum hwmon_sensor_types type,
if (attr == hwmon_temp_input)
return s5_read_temp(hwmon, val);
break;
+ case hwmon_fan:
+ if (attr == hwmon_fan_input && hwmon->fan)
+ return s5_read_fan(hwmon, val);
+ break;
default:
break;
}
@@ -82,12 +135,15 @@ static int s5_read(struct device *dev, enum hwmon_sensor_types type,
static umode_t s5_is_visible(const void *_data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
- if (type != hwmon_temp)
- return 0;
+ const struct s5_hwmon *hwmon = _data;
- switch (attr) {
- case hwmon_temp_input:
- return 0444;
+ switch (type) {
+ case hwmon_temp:
+ return attr == hwmon_temp_input ? 0444 : 0;
+ case hwmon_fan:
+ if (hwmon->fan && attr == hwmon_fan_input)
+ return 0444;
+ return 0;
default:
return 0;
}
@@ -96,6 +152,7 @@ static umode_t s5_is_visible(const void *_data, enum hwmon_sensor_types type,
static const struct hwmon_channel_info * const s5_info[] = {
HWMON_CHANNEL_INFO(chip, HWMON_C_REGISTER_TZ),
HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT),
NULL
};
@@ -111,10 +168,15 @@ static const struct hwmon_chip_info s5_chip_info = {
static int s5_temp_probe(struct platform_device *pdev)
{
+ const struct s5_match_data *match_data;
+ struct device *dev = &pdev->dev;
struct device *hwmon_dev;
struct s5_hwmon *hwmon;
+ struct device_node *fan_np __free(device_node) = NULL;
- hwmon = devm_kzalloc(&pdev->dev, sizeof(*hwmon), GFP_KERNEL);
+ match_data = device_get_match_data(dev);
+
+ hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
if (!hwmon)
return -ENOMEM;
@@ -122,14 +184,32 @@ static int s5_temp_probe(struct platform_device *pdev)
if (IS_ERR(hwmon->base))
return PTR_ERR(hwmon->base);
- hwmon->clk = devm_clk_get_enabled(&pdev->dev, NULL);
+ if (match_data && match_data->has_fan) {
+ hwmon->fan = devm_platform_ioremap_resource_byname(pdev, "fan");
+ if (IS_ERR(hwmon->fan))
+ return PTR_ERR(hwmon->fan);
+
+ hwmon->pulses_per_revolution = 2;
+ fan_np = of_get_available_child_by_name(dev->of_node, "fan");
+ if (fan_np)
+ of_property_read_u32(fan_np, "pulses-per-revolution",
+ &hwmon->pulses_per_revolution);
+ if (!hwmon->pulses_per_revolution ||
+ hwmon->pulses_per_revolution > 4)
+ return dev_err_probe(dev, -EINVAL,
+ "invalid pulses-per-revolution\n");
+ }
+
+ hwmon->clk = devm_clk_get_enabled(dev, NULL);
if (IS_ERR(hwmon->clk))
return PTR_ERR(hwmon->clk);
+ hwmon->clk_rate = clk_get_rate(hwmon->clk);
s5_temp_enable(hwmon);
+ if (hwmon->fan)
+ s5_fan_enable(hwmon);
- hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev,
- "s5_temp",
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, "s5_temp",
hwmon,
&s5_chip_info,
NULL);
@@ -137,7 +217,15 @@ static int s5_temp_probe(struct platform_device *pdev)
return PTR_ERR_OR_ZERO(hwmon_dev);
}
+static const struct s5_match_data lan969x_match_data = {
+ .has_fan = true,
+};
+
static const struct of_device_id s5_temp_match[] = {
+ {
+ .compatible = "microchip,lan9691-hwmon",
+ .data = &lan969x_match_data,
+ },
{ .compatible = "microchip,sparx5-temp" },
{},
};
@@ -154,5 +242,5 @@ static struct platform_driver s5_temp_driver = {
module_platform_driver(s5_temp_driver);
MODULE_AUTHOR("Lars Povlsen <lars.povlsen at microchip.com>");
-MODULE_DESCRIPTION("Sparx5 SoC temperature sensor driver");
+MODULE_DESCRIPTION("Sparx5 SoC hardware monitoring driver");
MODULE_LICENSE("GPL");
--
2.56.0
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