tg3: Add hwmon support for temperature

Some tg3 devices have management firmware that can export sensor data.
Export temperature sensor reading via hwmon sysfs.

[hwmon interface suggested by Ben Hutchings <bhutchings@solarflare.com>]

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: Nithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 150 insertions, 0 deletions

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 26ca36810e72..fce4c1e4dd3f 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -44,6 +44,10 @@
 #include <linux/prefetch.h>
 #include <linux/dma-mapping.h>
 #include <linux/firmware.h>
+#if IS_ENABLED(CONFIG_HWMON)
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#endif
 
 #include <net/checksum.h>
 #include <net/ip.h>
@@ -9481,6 +9485,110 @@ static int tg3_init_hw(struct tg3 *tp, int reset_phy)
         return tg3_reset_hw(tp, reset_phy);
 }
 
+#if IS_ENABLED(CONFIG_HWMON)
+static void tg3_sd_scan_scratchpad(struct tg3 *tp, struct tg3_ocir *ocir)
+{
+        int i;
+
+        for (i = 0; i < TG3_SD_NUM_RECS; i++, ocir++) {
+                u32 off = i * TG3_OCIR_LEN, len = TG3_OCIR_LEN;
+
+                tg3_ape_scratchpad_read(tp, (u32 *) ocir, off, len);
+                off += len;
+
+                if (ocir->signature != TG3_OCIR_SIG_MAGIC ||
+                    !(ocir->version_flags & TG3_OCIR_FLAG_ACTIVE))
+                        memset(ocir, 0, TG3_OCIR_LEN);
+        }
+}
+
+/* sysfs attributes for hwmon */
+static ssize_t tg3_show_temp(struct device *dev,
+                             struct device_attribute *devattr, char *buf)
+{
+        struct pci_dev *pdev = to_pci_dev(dev);
+        struct net_device *netdev = pci_get_drvdata(pdev);
+        struct tg3 *tp = netdev_priv(netdev);
+        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+        u32 temperature;
+
+        spin_lock_bh(&tp->lock);
+        tg3_ape_scratchpad_read(tp, &temperature, attr->index,
+                                sizeof(temperature));
+        spin_unlock_bh(&tp->lock);
+        return sprintf(buf, "%u\n", temperature);
+}
+
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tg3_show_temp, NULL,
+                          TG3_TEMP_SENSOR_OFFSET);
+static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, tg3_show_temp, NULL,
+                          TG3_TEMP_CAUTION_OFFSET);
+static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, tg3_show_temp, NULL,
+                          TG3_TEMP_MAX_OFFSET);
+
+static struct attribute *tg3_attributes[] = {
+        &sensor_dev_attr_temp1_input.dev_attr.attr,
+        &sensor_dev_attr_temp1_crit.dev_attr.attr,
+        &sensor_dev_attr_temp1_max.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group tg3_group = {
+        .attrs = tg3_attributes,
+};
+
+#endif
+
+static void tg3_hwmon_close(struct tg3 *tp)
+{
+#if IS_ENABLED(CONFIG_HWMON)
+        if (tp->hwmon_dev) {
+                hwmon_device_unregister(tp->hwmon_dev);
+                tp->hwmon_dev = NULL;
+                sysfs_remove_group(&tp->pdev->dev.kobj, &tg3_group);
+        }
+#endif
+}
+
+static void tg3_hwmon_open(struct tg3 *tp)
+{
+#if IS_ENABLED(CONFIG_HWMON)
+        int i, err;
+        u32 size = 0;
+        struct pci_dev *pdev = tp->pdev;
+        struct tg3_ocir ocirs[TG3_SD_NUM_RECS];
+
+        tg3_sd_scan_scratchpad(tp, ocirs);
+
+        for (i = 0; i < TG3_SD_NUM_RECS; i++) {
+                if (!ocirs[i].src_data_length)
+                        continue;
+
+                size += ocirs[i].src_hdr_length;
+                size += ocirs[i].src_data_length;
+        }
+
+        if (!size)
+                return;
+
+        /* Register hwmon sysfs hooks */
+        err = sysfs_create_group(&pdev->dev.kobj, &tg3_group);
+        if (err) {
+                dev_err(&pdev->dev, "Cannot create sysfs group, aborting\n");
+                return;
+        }
+
+        tp->hwmon_dev = hwmon_device_register(&pdev->dev);
+        if (IS_ERR(tp->hwmon_dev)) {
+                tp->hwmon_dev = NULL;
+                dev_err(&pdev->dev, "Cannot register hwmon device, aborting\n");
+                sysfs_remove_group(&pdev->dev.kobj, &tg3_group);
+        }
+#endif
+}
+
+
 #define TG3_STAT_ADD32(PSTAT, REG) \
 do {    u32 __val = tr32(REG); \
         (PSTAT)->low += __val; \
@@ -10189,6 +10297,8 @@ static int tg3_open(struct net_device *dev)
 
         tg3_phy_start(tp);
 
+        tg3_hwmon_open(tp);
+
         tg3_full_lock(tp, 0);
 
         tg3_timer_start(tp);
@@ -10238,6 +10348,8 @@ static int tg3_close(struct net_device *dev)
 
         tg3_timer_stop(tp);
 
+        tg3_hwmon_close(tp);
+
         tg3_phy_stop(tp);
 
         tg3_full_lock(tp, 1);
diff --git a/drivers/net/ethernet/broadcom/tg3.h b/drivers/net/ethernet/broadcom/tg3.h
index f8a0d9c0e990..a1b75cd67b9d 100644
--- a/drivers/net/ethernet/broadcom/tg3.h
+++ b/drivers/net/ethernet/broadcom/tg3.h
@@ -2676,6 +2676,40 @@ struct tg3_hw_stats {
         u8                              __reserved4[0xb00-0x9c8];
 };
 
+#define TG3_SD_NUM_RECS                 3
+#define TG3_OCIR_LEN                    (sizeof(struct tg3_ocir))
+#define TG3_OCIR_SIG_MAGIC              0x5253434f
+#define TG3_OCIR_FLAG_ACTIVE            0x00000001
+
+#define TG3_TEMP_CAUTION_OFFSET         0xc8
+#define TG3_TEMP_MAX_OFFSET             0xcc
+#define TG3_TEMP_SENSOR_OFFSET          0xd4
+
+
+struct tg3_ocir {
+        u32                             signature;
+        u16                             version_flags;
+        u16                             refresh_int;
+        u32                             refresh_tmr;
+        u32                             update_tmr;
+        u32                             dst_base_addr;
+        u16                             src_hdr_offset;
+        u16                             src_hdr_length;
+        u16                             src_data_offset;
+        u16                             src_data_length;
+        u16                             dst_hdr_offset;
+        u16                             dst_data_offset;
+        u16                             dst_reg_upd_offset;
+        u16                             dst_sem_offset;
+        u32                             reserved1[2];
+        u32                             port0_flags;
+        u32                             port1_flags;
+        u32                             port2_flags;
+        u32                             port3_flags;
+        u32                             reserved2[1];
+};
+
+
 /* 'mapping' is superfluous as the chip does not write into
  * the tx/rx post rings so we could just fetch it from there.
  * But the cache behavior is better how we are doing it now.
@@ -3211,6 +3245,10 @@ struct tg3 {
         const char                      *fw_needed;
         const struct firmware           *fw;
         u32                             fw_len; /* includes BSS */
+
+#if IS_ENABLED(CONFIG_HWMON)
+        struct device                   *hwmon_dev;
+#endif
 };
 
 #endif /* !(_T3_H) */