The GPY115 and GPY2xx PHYs contain an integrated temperature sensor. It
accuracy is +/- 5°C. Add support for it.
Signed-off-by: Michael Walle <michael@xxxxxxxx>
---
drivers/net/phy/Kconfig | 2 +
drivers/net/phy/mxl-gpy.c | 106 ++++++++++++++++++++++++++++++++++++++
2 files changed, 108 insertions(+)
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 9fee639ee5c8..09fa17796d4d 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -216,6 +216,8 @@ config MARVELL_88X2222_PHY
config MAXLINEAR_GPHY
tristate "Maxlinear Ethernet PHYs"
+ select POLYNOMIAL if HWMON
+ depends on HWMON || HWMON=n
help
Support for the Maxlinear GPY115, GPY211, GPY212, GPY215,
GPY241, GPY245 PHYs.
diff --git a/drivers/net/phy/mxl-gpy.c b/drivers/net/phy/mxl-gpy.c
index 6c4da2f9e90a..5b99acf44337 100644
--- a/drivers/net/phy/mxl-gpy.c
+++ b/drivers/net/phy/mxl-gpy.c
@@ -8,7 +8,9 @@
#include <linux/module.h>
#include <linux/bitfield.h>
+#include <linux/hwmon.h>
#include <linux/phy.h>
+#include <linux/polynomial.h>
#include <linux/netdevice.h>
/* PHY ID */
@@ -64,6 +66,10 @@
#define VSPEC1_SGMII_ANEN_ANRS (VSPEC1_SGMII_CTRL_ANEN | \
VSPEC1_SGMII_CTRL_ANRS)
+/* Temperature sensor */
+#define VPSPEC1_TEMP_STA 0x0E
+#define VPSPEC1_TEMP_STA_DATA GENMASK(9, 0)
+
/* WoL */
#define VPSPEC2_WOL_CTL 0x0E06
#define VPSPEC2_WOL_AD01 0x0E08
@@ -80,6 +86,102 @@ static const struct {
{9, 0x73},
};
+#if IS_ENABLED(CONFIG_HWMON)
+/* The original translation formulae of the temperature (in degrees of Celsius)
+ * are as follows:
+ *
+ * T = -2.5761e-11*(N^4) + 9.7332e-8*(N^3) + -1.9165e-4*(N^2) +
+ * 3.0762e-1*(N^1) + -5.2156e1
+ *
+ * where [-52.156, 137.961]C and N = [0, 1023].
+ *
+ * They must be accordingly altered to be suitable for the integer arithmetics.
+ * The technique is called 'factor redistribution', which just makes sure the
+ * multiplications and divisions are made so to have a result of the operations
+ * within the integer numbers limit. In addition we need to translate the
+ * formulae to accept millidegrees of Celsius. Here what it looks like after
+ * the alterations:
+ *
+ * T = -25761e-12*(N^4) + 97332e-9*(N^3) + -191650e-6*(N^2) +
+ * 307620e-3*(N^1) + -52156
+ *
+ * where T = [-52156, 137961]mC and N = [0, 1023].
+ */
+static const struct polynomial poly_N_to_temp = {
+ .terms = {
+ {4, -25761, 1000, 1},
+ {3, 97332, 1000, 1},
+ {2, -191650, 1000, 1},
+ {1, 307620, 1000, 1},
+ {0, -52156, 1, 1}
+ }
+};
+
+static int gpy_hwmon_read(struct device *dev,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel, long *value)
+{
+ struct phy_device *phydev = dev_get_drvdata(dev);
+ int ret;
+
+ ret = phy_read_mmd(phydev, MDIO_MMD_VEND1, VPSPEC1_TEMP_STA);
+ if (ret < 0)
+ return ret;
+ if (!ret)
+ return -ENODATA;
+
+ *value = polynomial_calc(&poly_N_to_temp,
+ FIELD_GET(VPSPEC1_TEMP_STA_DATA, ret));
+
+ return 0;
+}
+
+static umode_t gpy_hwmon_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ return 0444;
+}
+
+static const struct hwmon_channel_info *gpy_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ NULL
+};
+
+static const struct hwmon_ops gpy_hwmon_hwmon_ops = {
+ .is_visible = gpy_hwmon_is_visible,
+ .read = gpy_hwmon_read,
+};
+
+static const struct hwmon_chip_info gpy_hwmon_chip_info = {
+ .ops = &gpy_hwmon_hwmon_ops,
+ .info = gpy_hwmon_info,
+};
+
+static int gpy_hwmon_register(struct phy_device *phydev)
+{
+ struct device *dev = &phydev->mdio.dev;
+ struct device *hwmon_dev;
+ char *hwmon_name;
+
+ hwmon_name = devm_hwmon_sanitize_name(dev, dev_name(dev));
+ if (IS_ERR(hwmon_name))
+ return PTR_ERR(hwmon_name);
+
+ hwmon_dev = devm_hwmon_device_register_with_info(dev, hwmon_name,
+ phydev,
+ &gpy_hwmon_chip_info,
+ NULL);
+
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+#else
+static int gpy_hwmon_register(struct phy_device *phydev)
+{
+ return 0;
+}
+#endif
+
static int gpy_config_init(struct phy_device *phydev)
{
int ret;
@@ -109,6 +211,10 @@ static int gpy_probe(struct phy_device *phydev)
if (ret < 0)
return ret;
+ ret = gpy_hwmon_register(phydev);
+ if (ret)
+ return ret;
+
phydev_info(phydev, "Firmware Version: 0x%04X (%s)\n", ret,
(ret & PHY_FWV_REL_MASK) ? "release" : "test");
--
2.30.2
