[PATCH net-next v3 3/3] net: phy: bcm54140: add hwmon support

From: Michael Walle
Date: Mon Apr 20 2020 - 14:21:34 EST


The PHY supports monitoring its die temperature as well as two analog
voltages. Add support for it.

Signed-off-by: Michael Walle <michael@xxxxxxxx>
Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
---
changes since v2:
- fixed messed up #if IS_ENABLED(CONFIG_HWMON) fences
- removed channel parameter from bcm54140_hwmon_read_temp()

changes since v1:
- add IS_ENABLED(CONFIG_HWMON) guards
- clamp values before conversion
- add mutex alarm_lock
- use mdiobus_get_phy()
- make CONFIG_BCM54140_PHY depend on HWMON (or disabled altogether)
- add BCM54140_HWMON_IN_xx(ch) macros

Btw. is it possible to rely on the compiler to strip away unused
function calls. For exmaple, instead of using the
#if IS_ENABLED(CONFIG_HWMON) guards, one could use the following:

if (IS_ENABLED(CONFIG_HWMON))
if (!bcm54140_is_pkg_init(phydev)) {
ret = bcm54140_phy_probe_once(phydev);
if (ret)
return ret;
}
}

This will then optimize away the devm_hwmon_device_register() call.

Documentation/hwmon/bcm54140.rst | 45 ++++
Documentation/hwmon/index.rst | 1 +
drivers/net/phy/Kconfig | 1 +
drivers/net/phy/bcm54140.c | 396 +++++++++++++++++++++++++++++++
4 files changed, 443 insertions(+)
create mode 100644 Documentation/hwmon/bcm54140.rst

diff --git a/Documentation/hwmon/bcm54140.rst b/Documentation/hwmon/bcm54140.rst
new file mode 100644
index 000000000000..bc6ea4b45966
--- /dev/null
+++ b/Documentation/hwmon/bcm54140.rst
@@ -0,0 +1,45 @@
+.. SPDX-License-Identifier: GPL-2.0-only
+
+Broadcom BCM54140 Quad SGMII/QSGMII PHY
+=======================================
+
+Supported chips:
+
+ * Broadcom BCM54140
+
+ Datasheet: not public
+
+Author: Michael Walle <michael@xxxxxxxx>
+
+Description
+-----------
+
+The Broadcom BCM54140 is a Quad SGMII/QSGMII PHY which supports monitoring
+its die temperature as well as two analog voltages.
+
+The AVDDL is a 1.0V analogue voltage, the AVDDH is a 3.3V analogue voltage.
+Both voltages and the temperature are measured in a round-robin fashion.
+
+Sysfs entries
+-------------
+
+The following attributes are supported.
+
+======================= ========================================================
+in0_label "AVDDL"
+in0_input Measured AVDDL voltage.
+in0_min Minimum AVDDL voltage.
+in0_max Maximum AVDDL voltage.
+in0_alarm AVDDL voltage alarm.
+
+in1_label "AVDDH"
+in1_input Measured AVDDH voltage.
+in1_min Minimum AVDDH voltage.
+in1_max Maximum AVDDH voltage.
+in1_alarm AVDDH voltage alarm.
+
+temp1_input Die temperature.
+temp1_min Minimum die temperature.
+temp1_max Maximum die temperature.
+temp1_alarm Die temperature alarm.
+======================= ========================================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index f022583f96f6..19ad0846736d 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -42,6 +42,7 @@ Hardware Monitoring Kernel Drivers
asb100
asc7621
aspeed-pwm-tacho
+ bcm54140
bel-pfe
coretemp
da9052
diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index cb7936b577de..bacfee41b564 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -349,6 +349,7 @@ config BROADCOM_PHY
config BCM54140_PHY
tristate "Broadcom BCM54140 PHY"
depends on PHYLIB
+ depends on HWMON || HWMON=n
select BCM_NET_PHYLIB
help
Support the Broadcom BCM54140 Quad SGMII/QSGMII PHY.
diff --git a/drivers/net/phy/bcm54140.c b/drivers/net/phy/bcm54140.c
index 0eeb60de67f8..aa854477e06a 100644
--- a/drivers/net/phy/bcm54140.c
+++ b/drivers/net/phy/bcm54140.c
@@ -6,6 +6,7 @@

#include <linux/bitfield.h>
#include <linux/brcmphy.h>
+#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/phy.h>

@@ -50,6 +51,69 @@
#define BCM54140_RDB_TOP_IMR_PORT1 BIT(5)
#define BCM54140_RDB_TOP_IMR_PORT2 BIT(6)
#define BCM54140_RDB_TOP_IMR_PORT3 BIT(7)
+#define BCM54140_RDB_MON_CTRL 0x831 /* monitor control */
+#define BCM54140_RDB_MON_CTRL_V_MODE BIT(3) /* voltage mode */
+#define BCM54140_RDB_MON_CTRL_SEL_MASK GENMASK(2, 1)
+#define BCM54140_RDB_MON_CTRL_SEL_TEMP 0 /* meassure temperature */
+#define BCM54140_RDB_MON_CTRL_SEL_1V0 1 /* meassure AVDDL 1.0V */
+#define BCM54140_RDB_MON_CTRL_SEL_3V3 2 /* meassure AVDDH 3.3V */
+#define BCM54140_RDB_MON_CTRL_SEL_RR 3 /* meassure all round-robin */
+#define BCM54140_RDB_MON_CTRL_PWR_DOWN BIT(0) /* power-down monitor */
+#define BCM54140_RDB_MON_TEMP_VAL 0x832 /* temperature value */
+#define BCM54140_RDB_MON_TEMP_MAX 0x833 /* temperature high thresh */
+#define BCM54140_RDB_MON_TEMP_MIN 0x834 /* temperature low thresh */
+#define BCM54140_RDB_MON_TEMP_DATA_MASK GENMASK(9, 0)
+#define BCM54140_RDB_MON_1V0_VAL 0x835 /* AVDDL 1.0V value */
+#define BCM54140_RDB_MON_1V0_MAX 0x836 /* AVDDL 1.0V high thresh */
+#define BCM54140_RDB_MON_1V0_MIN 0x837 /* AVDDL 1.0V low thresh */
+#define BCM54140_RDB_MON_1V0_DATA_MASK GENMASK(10, 0)
+#define BCM54140_RDB_MON_3V3_VAL 0x838 /* AVDDH 3.3V value */
+#define BCM54140_RDB_MON_3V3_MAX 0x839 /* AVDDH 3.3V high thresh */
+#define BCM54140_RDB_MON_3V3_MIN 0x83a /* AVDDH 3.3V low thresh */
+#define BCM54140_RDB_MON_3V3_DATA_MASK GENMASK(11, 0)
+#define BCM54140_RDB_MON_ISR 0x83b /* interrupt status */
+#define BCM54140_RDB_MON_ISR_3V3 BIT(2) /* AVDDH 3.3V alarm */
+#define BCM54140_RDB_MON_ISR_1V0 BIT(1) /* AVDDL 1.0V alarm */
+#define BCM54140_RDB_MON_ISR_TEMP BIT(0) /* temperature alarm */
+
+/* According to the datasheet the formula is:
+ * T = 413.35 - (0.49055 * bits[9:0])
+ */
+#define BCM54140_HWMON_TO_TEMP(v) (413350L - (v) * 491)
+#define BCM54140_HWMON_FROM_TEMP(v) DIV_ROUND_CLOSEST_ULL(413350L - (v), 491)
+
+/* According to the datasheet the formula is:
+ * U = bits[11:0] / 1024 * 220 / 0.2
+ *
+ * Normalized:
+ * U = bits[11:0] / 4096 * 2514
+ */
+#define BCM54140_HWMON_TO_IN_1V0(v) ((v) * 2514 >> 11)
+#define BCM54140_HWMON_FROM_IN_1V0(v) DIV_ROUND_CLOSEST_ULL(((v) << 11), 2514)
+
+/* According to the datasheet the formula is:
+ * U = bits[10:0] / 1024 * 880 / 0.7
+ *
+ * Normalized:
+ * U = bits[10:0] / 2048 * 4400
+ */
+#define BCM54140_HWMON_TO_IN_3V3(v) ((v) * 4400 >> 12)
+#define BCM54140_HWMON_FROM_IN_3V3(v) DIV_ROUND_CLOSEST_ULL(((v) << 12), 4400)
+
+#define BCM54140_HWMON_TO_IN(ch, v) ((ch) ? BCM54140_HWMON_TO_IN_3V3(v) \
+ : BCM54140_HWMON_TO_IN_1V0(v))
+#define BCM54140_HWMON_FROM_IN(ch, v) ((ch) ? BCM54140_HWMON_FROM_IN_3V3(v) \
+ : BCM54140_HWMON_FROM_IN_1V0(v))
+#define BCM54140_HWMON_IN_MASK(ch) ((ch) ? BCM54140_RDB_MON_3V3_DATA_MASK \
+ : BCM54140_RDB_MON_1V0_DATA_MASK)
+#define BCM54140_HWMON_IN_VAL_REG(ch) ((ch) ? BCM54140_RDB_MON_3V3_VAL \
+ : BCM54140_RDB_MON_1V0_VAL)
+#define BCM54140_HWMON_IN_MIN_REG(ch) ((ch) ? BCM54140_RDB_MON_3V3_MIN \
+ : BCM54140_RDB_MON_1V0_MIN)
+#define BCM54140_HWMON_IN_MAX_REG(ch) ((ch) ? BCM54140_RDB_MON_3V3_MAX \
+ : BCM54140_RDB_MON_1V0_MAX)
+#define BCM54140_HWMON_IN_ALARM_BIT(ch) ((ch) ? BCM54140_RDB_MON_ISR_3V3 \
+ : BCM54140_RDB_MON_ISR_1V0)

#define BCM54140_DEFAULT_DOWNSHIFT 5
#define BCM54140_MAX_DOWNSHIFT 9
@@ -57,8 +121,328 @@
struct bcm54140_priv {
int port;
int base_addr;
+#if IS_ENABLED(CONFIG_HWMON)
+ bool pkg_init;
+ /* protect the alarm bits */
+ struct mutex alarm_lock;
+ u16 alarm;
+#endif
};

+#if IS_ENABLED(CONFIG_HWMON)
+static umode_t bcm54140_hwmon_is_visible(const void *data,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ switch (type) {
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_min:
+ case hwmon_in_max:
+ return 0644;
+ case hwmon_in_label:
+ case hwmon_in_input:
+ case hwmon_in_alarm:
+ return 0444;
+ default:
+ return 0;
+ }
+ case hwmon_temp:
+ switch (attr) {
+ case hwmon_temp_min:
+ case hwmon_temp_max:
+ return 0644;
+ case hwmon_temp_input:
+ case hwmon_temp_alarm:
+ return 0444;
+ default:
+ return 0;
+ }
+ default:
+ return 0;
+ }
+}
+
+static int bcm54140_hwmon_read_alarm(struct device *dev, unsigned int bit,
+ long *val)
+{
+ struct phy_device *phydev = dev_get_drvdata(dev);
+ struct bcm54140_priv *priv = phydev->priv;
+ int tmp, ret = 0;
+
+ mutex_lock(&priv->alarm_lock);
+
+ /* latch any alarm bits */
+ tmp = bcm_phy_read_rdb(phydev, BCM54140_RDB_MON_ISR);
+ if (tmp < 0) {
+ ret = tmp;
+ goto out;
+ }
+ priv->alarm |= tmp;
+
+ *val = !!(priv->alarm & bit);
+ priv->alarm &= ~bit;
+
+out:
+ mutex_unlock(&priv->alarm_lock);
+ return ret;
+}
+
+static int bcm54140_hwmon_read_temp(struct device *dev, u32 attr, long *val)
+{
+ struct phy_device *phydev = dev_get_drvdata(dev);
+ u16 reg, tmp;
+
+ switch (attr) {
+ case hwmon_temp_input:
+ reg = BCM54140_RDB_MON_TEMP_VAL;
+ break;
+ case hwmon_temp_min:
+ reg = BCM54140_RDB_MON_TEMP_MIN;
+ break;
+ case hwmon_temp_max:
+ reg = BCM54140_RDB_MON_TEMP_MAX;
+ break;
+ case hwmon_temp_alarm:
+ return bcm54140_hwmon_read_alarm(dev,
+ BCM54140_RDB_MON_ISR_TEMP,
+ val);
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ tmp = bcm_phy_read_rdb(phydev, reg);
+ if (tmp < 0)
+ return tmp;
+
+ *val = BCM54140_HWMON_TO_TEMP(tmp & BCM54140_RDB_MON_TEMP_DATA_MASK);
+
+ return 0;
+}
+
+static int bcm54140_hwmon_read_in(struct device *dev, u32 attr,
+ int channel, long *val)
+{
+ struct phy_device *phydev = dev_get_drvdata(dev);
+ u16 bit, reg, tmp;
+
+ switch (attr) {
+ case hwmon_in_input:
+ reg = BCM54140_HWMON_IN_VAL_REG(channel);
+ break;
+ case hwmon_in_min:
+ reg = BCM54140_HWMON_IN_MIN_REG(channel);
+ break;
+ case hwmon_in_max:
+ reg = BCM54140_HWMON_IN_MAX_REG(channel);
+ break;
+ case hwmon_in_alarm:
+ bit = BCM54140_HWMON_IN_ALARM_BIT(channel);
+ return bcm54140_hwmon_read_alarm(dev, bit, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ tmp = bcm_phy_read_rdb(phydev, reg);
+ if (tmp < 0)
+ return tmp;
+
+ tmp &= BCM54140_HWMON_IN_MASK(channel);
+ *val = BCM54140_HWMON_TO_IN(channel, tmp);
+
+ return 0;
+}
+
+static int bcm54140_hwmon_read(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel, long *val)
+{
+ switch (type) {
+ case hwmon_temp:
+ return bcm54140_hwmon_read_temp(dev, attr, val);
+ case hwmon_in:
+ return bcm54140_hwmon_read_in(dev, attr, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static const char *const bcm54140_hwmon_in_labels[] = {
+ "AVDDL",
+ "AVDDH",
+};
+
+static int bcm54140_hwmon_read_string(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel, const char **str)
+{
+ switch (type) {
+ case hwmon_in:
+ switch (attr) {
+ case hwmon_in_label:
+ *str = bcm54140_hwmon_in_labels[channel];
+ return 0;
+ default:
+ return -EOPNOTSUPP;
+ }
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static int bcm54140_hwmon_write_temp(struct device *dev, u32 attr,
+ int channel, long val)
+{
+ struct phy_device *phydev = dev_get_drvdata(dev);
+ u16 mask = BCM54140_RDB_MON_TEMP_DATA_MASK;
+ u16 reg;
+
+ val = clamp_val(val, BCM54140_HWMON_TO_TEMP(mask),
+ BCM54140_HWMON_TO_TEMP(0));
+
+ switch (attr) {
+ case hwmon_temp_min:
+ reg = BCM54140_RDB_MON_TEMP_MIN;
+ break;
+ case hwmon_temp_max:
+ reg = BCM54140_RDB_MON_TEMP_MAX;
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return bcm_phy_modify_rdb(phydev, reg, mask,
+ BCM54140_HWMON_FROM_TEMP(val));
+}
+
+static int bcm54140_hwmon_write_in(struct device *dev, u32 attr,
+ int channel, long val)
+{
+ struct phy_device *phydev = dev_get_drvdata(dev);
+ u16 mask = BCM54140_HWMON_IN_MASK(channel);
+ u16 reg;
+
+ val = clamp_val(val, 0, BCM54140_HWMON_TO_IN(channel, mask));
+
+ switch (attr) {
+ case hwmon_in_min:
+ reg = BCM54140_HWMON_IN_MIN_REG(channel);
+ break;
+ case hwmon_in_max:
+ reg = BCM54140_HWMON_IN_MAX_REG(channel);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return bcm_phy_modify_rdb(phydev, reg, mask,
+ BCM54140_HWMON_FROM_IN(channel, val));
+}
+
+static int bcm54140_hwmon_write(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel, long val)
+{
+ switch (type) {
+ case hwmon_temp:
+ return bcm54140_hwmon_write_temp(dev, attr, channel, val);
+ case hwmon_in:
+ return bcm54140_hwmon_write_in(dev, attr, channel, val);
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+
+static const struct hwmon_channel_info *bcm54140_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(temp,
+ HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
+ HWMON_T_ALARM),
+ HWMON_CHANNEL_INFO(in,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX |
+ HWMON_I_ALARM | HWMON_I_LABEL,
+ HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX |
+ HWMON_I_ALARM | HWMON_I_LABEL),
+ NULL
+};
+
+static const struct hwmon_ops bcm54140_hwmon_ops = {
+ .is_visible = bcm54140_hwmon_is_visible,
+ .read = bcm54140_hwmon_read,
+ .read_string = bcm54140_hwmon_read_string,
+ .write = bcm54140_hwmon_write,
+};
+
+static const struct hwmon_chip_info bcm54140_chip_info = {
+ .ops = &bcm54140_hwmon_ops,
+ .info = bcm54140_hwmon_info,
+};
+
+static int bcm54140_enable_monitoring(struct phy_device *phydev)
+{
+ u16 mask, set;
+
+ /* 3.3V voltage mode */
+ set = BCM54140_RDB_MON_CTRL_V_MODE;
+
+ /* select round-robin */
+ mask = BCM54140_RDB_MON_CTRL_SEL_MASK;
+ set |= FIELD_PREP(BCM54140_RDB_MON_CTRL_SEL_MASK,
+ BCM54140_RDB_MON_CTRL_SEL_RR);
+
+ /* remove power-down bit */
+ mask |= BCM54140_RDB_MON_CTRL_PWR_DOWN;
+
+ return bcm_phy_modify_rdb(phydev, BCM54140_RDB_MON_CTRL, mask, set);
+}
+
+/* Check if one PHY has already done the init of the parts common to all PHYs
+ * in the Quad PHY package.
+ */
+static bool bcm54140_is_pkg_init(struct phy_device *phydev)
+{
+ struct bcm54140_priv *priv = phydev->priv;
+ struct mii_bus *bus = phydev->mdio.bus;
+ int base_addr = priv->base_addr;
+ struct phy_device *phy;
+ int i;
+
+ /* Quad PHY */
+ for (i = 0; i < 4; i++) {
+ phy = mdiobus_get_phy(bus, base_addr + i);
+ if (!phy)
+ continue;
+
+ if ((phy->phy_id & phydev->drv->phy_id_mask) !=
+ (phydev->drv->phy_id & phydev->drv->phy_id_mask))
+ continue;
+
+ priv = phy->priv;
+
+ if (priv && priv->pkg_init)
+ return true;
+ }
+
+ return false;
+}
+
+static int bcm54140_probe_once(struct phy_device *phydev)
+{
+ struct device *hwmon;
+ int ret;
+
+ /* enable hardware monitoring */
+ ret = bcm54140_enable_monitoring(phydev);
+ if (ret)
+ return ret;
+
+ hwmon = devm_hwmon_device_register_with_info(&phydev->mdio.dev,
+ "BCM54140", phydev,
+ &bcm54140_chip_info,
+ NULL);
+ return PTR_ERR_OR_ZERO(hwmon);
+}
+#endif
+
static int bcm54140_base_read_rdb(struct phy_device *phydev, u16 rdb)
{
struct bcm54140_priv *priv = phydev->priv;
@@ -222,6 +606,18 @@ static int bcm54140_probe(struct phy_device *phydev)
if (ret)
return ret;

+#if IS_ENABLED(CONFIG_HWMON)
+ mutex_init(&priv->alarm_lock);
+
+ if (!bcm54140_is_pkg_init(phydev)) {
+ ret = bcm54140_probe_once(phydev);
+ if (ret)
+ return ret;
+ }
+
+ priv->pkg_init = true;
+#endif
+
phydev_dbg(phydev, "probed (port %d, base PHY address %d)\n",
priv->port, priv->base_addr);

--
2.20.1