Commit 09ce6b20 authored by Michael Walle's avatar Michael Walle Committed by Jakub Kicinski
Browse files

net: phy: mxl-gpy: add temperature sensor 



The GPY115 and GPY2xx PHYs contain an integrated temperature sensor. It
accuracy is +/- 5°C. Add support for it.

Signed-off-by: default avatarMichael Walle <michael@walle.cc>
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarAndrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220622141716.3517645-1-michael@walle.cc


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5dc48684

drivers/net/phy/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -221,6 +221,8 @@ 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.

drivers/net/phy/mxl-gpy.c

+106 −0
Original line number Diff line number Diff line
@@ -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");