On Wed, Jun 22, 2022 at 04:17:16PM +0200, Michael Walle wrote:
> 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>
Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> 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
>
