Re: [PATCH v5 3/4] hwmon: smpro: Add Ampere's Altra smpro-hwmon driver

From: Quan Nguyen
Date: Tue Jul 13 2021 - 19:45:44 EST


On 13/07/2021 22:28, Guenter Roeck wrote:
On 7/12/21 11:00 PM, Quan Nguyen wrote:
This commit adds support for Ampere SMpro hwmon driver. This driver
supports accessing various CPU sensors provided by the SMpro co-processor
including temperature, power, voltages, and current.

Signed-off-by: Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>

For my reference:

Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>

Thanks for the review.
- Quan

---
Changes in v5:
   + Drop ManufacturerID checking when probe as it was checked during
   smpro-mfd probing [Quan]
   + Drop the use of register offset [Quan]
   + Removed the use of compatible string as it is instantiated by
   smpro-mfd driver [Quan]
   + Thanks Guenter for the Reviewed-by in last version, but it was
   not added because there's some changes in this version. Really
   appreciate if you could help again, thank you.

Changes in v4:
   + Returned regmap_read() error code [Guenter]

Changes in v3:
   + Handled negative temperature value [Guenter]
   + Returned -ENODEV if Manufacturer ID is wrong [Guenter]
   + Refactored smpro_read_string() and smpro_temp_read() [Guenter]
   + Removed smpro_write() function [Guenter]
   + Added minor refactor changes [Quan]

Changes in v2:
   + Removed "virtual" sensors [Guenter]
   + Reported SOC_TDP as "Socket TDP" using max attributes [Guenter]
   + Corrected return error code when host is turn off [Guenter]
   + Reported MEM HOT Threshold for all DIMMs as temp*_crit [Guenter]
   + Removed license info as SPDX-License-Identifier existed [Guenter]
   + Added is_visible() support [Guenter]
   + Used HWMON_CHANNEL_INFO() macro and LABEL attributes [Guenter]
   + Made is_valid_id() return boolean [Guenter]
   + Returned -EPROBE_DEFER when smpro reg inaccessible [Guenter]
   + Removed unnecessary error message when dev register fail [Guenter]
   + Removed Socket TDP sensor [Quan]
   + Included sensor type and channel in labels [Quan]
   + Refactorized code to fix checkpatch.pl --strict complaint [Quan]

  drivers/hwmon/Kconfig       |   8 +
  drivers/hwmon/Makefile      |   1 +
  drivers/hwmon/smpro-hwmon.c | 463 ++++++++++++++++++++++++++++++++++++
  3 files changed, 472 insertions(+)
  create mode 100644 drivers/hwmon/smpro-hwmon.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index e3675377bc5d..903c5ef79a5a 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -67,6 +67,14 @@ config SENSORS_ABITUGURU3
        This driver can also be built as a module. If so, the module
        will be called abituguru3.
+config SENSORS_SMPRO
+    tristate "Ampere's Altra SMpro hardware monitoring driver"
+    depends on MFD_SMPRO
+    help
+      If you say yes here you get support for the thermal, voltage,
+      current and power sensors of Ampere's Altra processor family SoC
+      with SMpro co-processor.
+
  config SENSORS_AD7314
      tristate "Analog Devices AD7314 and compatibles"
      depends on SPI
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index d712c61c1f5e..9de5cd9911b0 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -175,6 +175,7 @@ obj-$(CONFIG_SENSORS_SHT4x)    += sht4x.o
  obj-$(CONFIG_SENSORS_SHTC1)    += shtc1.o
  obj-$(CONFIG_SENSORS_SIS5595)    += sis5595.o
  obj-$(CONFIG_SENSORS_SMM665)    += smm665.o
+obj-$(CONFIG_SENSORS_SMPRO)    += smpro-hwmon.o
  obj-$(CONFIG_SENSORS_SMSC47B397)+= smsc47b397.o
  obj-$(CONFIG_SENSORS_SMSC47M1)    += smsc47m1.o
  obj-$(CONFIG_SENSORS_SMSC47M192)+= smsc47m192.o
diff --git a/drivers/hwmon/smpro-hwmon.c b/drivers/hwmon/smpro-hwmon.c
new file mode 100644
index 000000000000..b01ceea33ddd
--- /dev/null
+++ b/drivers/hwmon/smpro-hwmon.c
@@ -0,0 +1,463 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Ampere Computing SoC's SMPro Hardware Monitoring Driver
+ *
+ * Copyright (c) 2021, Ampere Computing LLC
+ */
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+/* Logical Power Sensor Registers */
+#define SOC_TEMP        0x10
+#define SOC_VRD_TEMP        0x11
+#define DIMM_VRD_TEMP        0x12
+#define CORE_VRD_TEMP        0x13
+#define CH0_DIMM_TEMP        0x14
+#define CH1_DIMM_TEMP        0x15
+#define CH2_DIMM_TEMP        0x16
+#define CH3_DIMM_TEMP        0x17
+#define CH4_DIMM_TEMP        0x18
+#define CH5_DIMM_TEMP        0x19
+#define CH6_DIMM_TEMP        0x1A
+#define CH7_DIMM_TEMP        0x1B
+#define RCA_VRD_TEMP        0x1C
+
+#define CORE_VRD_PWR        0x20
+#define SOC_PWR            0x21
+#define DIMM_VRD1_PWR        0x22
+#define DIMM_VRD2_PWR        0x23
+#define CORE_VRD_PWR_MW        0x26
+#define SOC_PWR_MW        0x27
+#define DIMM_VRD1_PWR_MW    0x28
+#define DIMM_VRD2_PWR_MW    0x29
+#define RCA_VRD_PWR        0x2A
+#define RCA_VRD_PWR_MW        0x2B
+
+#define MEM_HOT_THRESHOLD    0x32
+#define SOC_VR_HOT_THRESHOLD    0x33
+#define CORE_VRD_VOLT        0x34
+#define SOC_VRD_VOLT        0x35
+#define DIMM_VRD1_VOLT        0x36
+#define DIMM_VRD2_VOLT        0x37
+#define RCA_VRD_VOLT        0x38
+
+#define CORE_VRD_CURR        0x39
+#define SOC_VRD_CURR        0x3A
+#define DIMM_VRD1_CURR        0x3B
+#define DIMM_VRD2_CURR        0x3C
+#define RCA_VRD_CURR        0x3D
+
+struct smpro_hwmon {
+    struct regmap *regmap;
+};
+
+struct smpro_sensor {
+    const u8 reg;
+    const u8 reg_ext;
+    const char *label;
+};
+
+static const struct smpro_sensor temperature[] = {
+    {
+        .reg = SOC_TEMP,
+        .label = "temp1 SoC"
+    },
+    {
+        .reg = SOC_VRD_TEMP,
+        .reg_ext = SOC_VR_HOT_THRESHOLD,
+        .label = "temp2 SoC VRD"
+    },
+    {
+        .reg = DIMM_VRD_TEMP,
+        .label = "temp3 DIMM VRD"
+    },
+    {
+        .reg = CORE_VRD_TEMP,
+        .label = "temp4 CORE VRD"
+    },
+    {
+        .reg = CH0_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp5 CH0 DIMM"
+    },
+    {
+        .reg = CH1_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp6 CH1 DIMM"
+    },
+    {
+        .reg = CH2_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp7 CH2 DIMM"
+    },
+    {
+        .reg = CH3_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp8 CH3 DIMM"
+    },
+    {
+        .reg = CH4_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp9 CH4 DIMM"
+    },
+    {
+        .reg = CH5_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp10 CH5 DIMM"
+    },
+    {
+        .reg = CH6_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp11 CH6 DIMM"
+    },
+    {
+        .reg = CH7_DIMM_TEMP,
+        .reg_ext = MEM_HOT_THRESHOLD,
+        .label = "temp12 CH7 DIMM"
+    },
+    {
+        .reg = RCA_VRD_TEMP,
+        .label = "temp13 RCA VRD"
+    },
+};
+
+static const struct smpro_sensor voltage[] = {
+    {
+        .reg = CORE_VRD_VOLT,
+        .label = "vout0 CORE VRD"
+    },
+    {
+        .reg = SOC_VRD_VOLT,
+        .label = "vout1 SoC VRD"
+    },
+    {
+        .reg = DIMM_VRD1_VOLT,
+        .label = "vout2 DIMM VRD1"
+    },
+    {
+        .reg = DIMM_VRD2_VOLT,
+        .label = "vout3 DIMM VRD2"
+    },
+    {
+        .reg = RCA_VRD_VOLT,
+        .label = "vout4 RCA VRD"
+    },
+};
+
+static const struct smpro_sensor curr_sensor[] = {
+    {
+        .reg = CORE_VRD_CURR,
+        .label = "iout1 CORE VRD"
+    },
+    {
+        .reg = SOC_VRD_CURR,
+        .label = "iout2 SoC VRD"
+    },
+    {
+        .reg = DIMM_VRD1_CURR,
+        .label = "iout3 DIMM VRD1"
+    },
+    {
+        .reg = DIMM_VRD2_CURR,
+        .label = "iout4 DIMM VRD2"
+    },
+    {
+        .reg = RCA_VRD_CURR,
+        .label = "iout5 RCA VRD"
+    },
+};
+
+static const struct smpro_sensor power[] = {
+    {
+        .reg = CORE_VRD_PWR,
+        .reg_ext = CORE_VRD_PWR_MW,
+        .label = "power1 CORE VRD"
+    },
+    {
+        .reg = SOC_PWR,
+        .reg_ext = SOC_PWR_MW,
+        .label = "power2 SoC"
+    },
+    {
+        .reg = DIMM_VRD1_PWR,
+        .reg_ext = DIMM_VRD1_PWR_MW,
+        .label = "power3 DIMM VRD1"
+    },
+    {
+        .reg = DIMM_VRD2_PWR,
+        .reg_ext = DIMM_VRD2_PWR_MW,
+        .label = "power4 DIMM VRD2"
+    },
+    {
+        .reg = RCA_VRD_PWR,
+        .reg_ext = RCA_VRD_PWR_MW,
+        .label = "power5 RCA VRD"
+    },
+};
+
+static int smpro_read_temp(struct device *dev, u32 attr, int channel, long *val)
+{
+    struct smpro_hwmon *hwmon = dev_get_drvdata(dev);
+    unsigned int value;
+    int ret;
+
+    switch (attr) {
+    case hwmon_temp_input:
+        ret = regmap_read(hwmon->regmap, temperature[channel].reg, &value);
+        if (ret)
+            return ret;
+        break;
+    case hwmon_temp_crit:
+        ret = regmap_read(hwmon->regmap, temperature[channel].reg_ext, &value);
+        if (ret)
+            return ret;
+        break;
+    default:
+        return -EOPNOTSUPP;
+    }
+
+    *val = sign_extend32(value, 8) * 1000;
+    return 0;
+}
+
+static int smpro_read_in(struct device *dev, u32 attr, int channel, long *val)
+{
+    struct smpro_hwmon *hwmon = dev_get_drvdata(dev);
+    unsigned int value;
+    int ret;
+
+    switch (attr) {
+    case hwmon_in_input:
+        ret = regmap_read(hwmon->regmap, voltage[channel].reg, &value);
+        if (ret < 0)
+            return ret;
+        /* 15-bit value in 1mV */
+        *val = value & 0x7fff;
+        return 0;
+    default:
+        return -EOPNOTSUPP;
+    }
+}
+
+static int smpro_read_curr(struct device *dev, u32 attr, int channel, long *val)
+{
+    struct smpro_hwmon *hwmon = dev_get_drvdata(dev);
+    unsigned int value;
+    int ret;
+
+    switch (attr) {
+    case hwmon_curr_input:
+        ret = regmap_read(hwmon->regmap, curr_sensor[channel].reg, &value);
+        if (ret < 0)
+            return ret;
+        /* Scale reported by the hardware is 1mA */
+        *val = value & 0x7fff;
+        return 0;
+    default:
+        return -EOPNOTSUPP;
+    }
+}
+
+static int smpro_read_power(struct device *dev, u32 attr, int channel, long *val_pwr)
+{
+    struct smpro_hwmon *hwmon = dev_get_drvdata(dev);
+    unsigned int val = 0, val_mw = 0;
+    int ret;
+
+    switch (attr) {
+    case hwmon_power_input:
+        ret = regmap_read(hwmon->regmap, power[channel].reg, &val);
+        if (ret)
+            return ret;
+
+        ret = regmap_read(hwmon->regmap, power[channel].reg_ext, &val_mw);
+        if (ret)
+            return ret;
+
+        *val_pwr = val * 1000000 + val_mw * 1000;
+        return 0;
+
+    default:
+        return -EOPNOTSUPP;
+    }
+}
+
+static int smpro_read(struct device *dev, enum hwmon_sensor_types type,
+              u32 attr, int channel, long *val)
+{
+    switch (type) {
+    case hwmon_temp:
+        return smpro_read_temp(dev, attr, channel, val);
+    case hwmon_in:
+        return smpro_read_in(dev, attr, channel, val);
+    case hwmon_power:
+        return smpro_read_power(dev, attr, channel, val);
+    case hwmon_curr:
+        return smpro_read_curr(dev, attr, channel, val);
+    default:
+        return -EOPNOTSUPP;
+    }
+}
+
+static int smpro_read_string(struct device *dev, enum hwmon_sensor_types type,
+                 u32 attr, int channel, const char **str)
+{
+    switch (type) {
+    case hwmon_temp:
+        switch (attr) {
+        case hwmon_temp_label:
+            *str = temperature[channel].label;
+            return 0;
+        default:
+            break;
+        }
+        break;
+
+    case hwmon_in:
+        switch (attr) {
+        case hwmon_in_label:
+            *str = voltage[channel].label;
+            return 0;
+        default:
+            break;
+        }
+        break;
+
+    case hwmon_curr:
+        switch (attr) {
+        case hwmon_curr_label:
+            *str = curr_sensor[channel].label;
+            return 0;
+        default:
+            break;
+        }
+        break;
+
+    case hwmon_power:
+        switch (attr) {
+        case hwmon_power_label:
+            *str = power[channel].label;
+            return 0;
+        default:
+            break;
+        }
+        break;
+    default:
+        break;
+    }
+
+    return -EOPNOTSUPP;
+}
+
+static umode_t smpro_is_visible(const void *data, enum hwmon_sensor_types type,
+                u32 attr, int channel)
+{
+    const struct smpro_hwmon *hwmon = data;
+    unsigned int value;
+    int ret;
+
+    switch (type) {
+    case hwmon_temp:
+        switch (attr) {
+        case hwmon_temp_input:
+        case hwmon_temp_label:
+        case hwmon_temp_crit:
+            ret = regmap_read(hwmon->regmap, temperature[channel].reg, &value);
+            if (ret || value == 0xFFFF)
+                return 0;
+        break;
+        }
+    default:
+        break;
+    }
+
+    return 0444;
+}
+
+static const struct hwmon_channel_info *smpro_info[] = {
+    HWMON_CHANNEL_INFO(temp,
+               HWMON_T_INPUT | HWMON_T_LABEL,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL,
+               HWMON_T_INPUT | HWMON_T_LABEL,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_CRIT,
+               HWMON_T_INPUT | HWMON_T_LABEL),
+    HWMON_CHANNEL_INFO(in,
+               HWMON_I_INPUT | HWMON_I_LABEL,
+               HWMON_I_INPUT | HWMON_I_LABEL,
+               HWMON_I_INPUT | HWMON_I_LABEL,
+               HWMON_I_INPUT | HWMON_I_LABEL,
+               HWMON_I_INPUT | HWMON_I_LABEL),
+    HWMON_CHANNEL_INFO(power,
+               HWMON_P_INPUT | HWMON_P_LABEL,
+               HWMON_P_INPUT | HWMON_P_LABEL,
+               HWMON_P_INPUT | HWMON_P_LABEL,
+               HWMON_P_INPUT | HWMON_P_LABEL,
+               HWMON_P_INPUT | HWMON_P_LABEL),
+    HWMON_CHANNEL_INFO(curr,
+               HWMON_C_INPUT | HWMON_C_LABEL,
+               HWMON_C_INPUT | HWMON_C_LABEL,
+               HWMON_C_INPUT | HWMON_C_LABEL,
+               HWMON_C_INPUT | HWMON_C_LABEL,
+               HWMON_C_INPUT | HWMON_C_LABEL),
+    NULL
+};
+
+static const struct hwmon_ops smpro_hwmon_ops = {
+    .is_visible = smpro_is_visible,
+    .read = smpro_read,
+    .read_string = smpro_read_string,
+};
+
+static const struct hwmon_chip_info smpro_chip_info = {
+    .ops = &smpro_hwmon_ops,
+    .info = smpro_info,
+};
+
+static int smpro_hwmon_probe(struct platform_device *pdev)
+{
+    struct smpro_hwmon *hwmon;
+    struct device *hwmon_dev;
+
+    hwmon = devm_kzalloc(&pdev->dev, sizeof(struct smpro_hwmon), GFP_KERNEL);
+    if (!hwmon)
+        return -ENOMEM;
+
+    hwmon->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+    if (!hwmon->regmap)
+        return -ENODEV;
+
+    hwmon_dev = devm_hwmon_device_register_with_info(&pdev->dev, "smpro_hwmon",
+                             hwmon, &smpro_chip_info, NULL);
+
+    return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static struct platform_driver smpro_hwmon_driver = {
+    .probe        = smpro_hwmon_probe,
+    .driver = {
+        .name    = "smpro-hwmon",
+    },
+};
+
+module_platform_driver(smpro_hwmon_driver);
+
+MODULE_AUTHOR("Thu Nguyen <thu@xxxxxxxxxxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Quan Nguyen <quan@xxxxxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Ampere Altra SMPro hwmon driver");
+MODULE_LICENSE("GPL v2");