[PATCH 3/8] Add Advantech EIO Hardware Monitor driver

[Ramiro Oliveira <ramiro.oliveira@advantech.com>]

This driver controls the Hardware Monitor block of the Advantech EIO chip.

Signed-off-by: Ramiro Oliveira <ramiro.oliveira@advantech.com>
---
 MAINTAINERS               |   1 +
 drivers/hwmon/Kconfig     |  10 ++
 drivers/hwmon/Makefile    |   1 +
 drivers/hwmon/eio-hwmon.c | 344 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 356 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 359d4a13f212..fdd39b152f41 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -620,6 +620,7 @@ ADVANTECH EIO DRIVER
 M:	Ramiro Oliveira <ramiro.oliveira@advantech.com>
 S:	Maintained
 F:	drivers/gpio/gpio-eio.c
+F:	drivers/hwmon/eio-hwmon.c
 F:	drivers/mfd/eio_core.c
 F:	include/linux/mfd/eio.h
 
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 157678b821fc..08993b993596 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -2043,6 +2043,16 @@ config SENSORS_DME1737
 	  This driver can also be built as a module. If so, the module
 	  will be called dme1737.
 
+config SENSORS_EIO
+	tristate "Advantech EIO HWMON"
+	depends on MFD_EIO
+	help
+	  If you say yes here you get support for the Advantech EIO
+	  temperature, voltage and fan speed monitoring block.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called eio-hwmon
+
 config SENSORS_EMC1403
 	tristate "SMSC EMC1403/23 thermal sensor"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index eade8e3b1bde..e69f03b41fae 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -72,6 +72,7 @@ obj-$(CONFIG_SENSORS_DME1737)	+= dme1737.o
 obj-$(CONFIG_SENSORS_DRIVETEMP)	+= drivetemp.o
 obj-$(CONFIG_SENSORS_DS620)	+= ds620.o
 obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o
+obj-$(CONFIG_SENSORS_EIO)	+= eio-hwmon.o
 obj-$(CONFIG_SENSORS_EMC1403)	+= emc1403.o
 obj-$(CONFIG_SENSORS_EMC2103)	+= emc2103.o
 obj-$(CONFIG_SENSORS_EMC2305)	+= emc2305.o
diff --git a/drivers/hwmon/eio-hwmon.c b/drivers/hwmon/eio-hwmon.c
new file mode 100644
index 000000000000..164591aa31a7
--- /dev/null
+++ b/drivers/hwmon/eio-hwmon.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * GPIO driver for Advantech EIO embedded controller.
+ *
+ * Copyright (C) 2025 Advantech Corporation. All rights reserved.
+ */
+
+#include <linux/errno.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/eio.h>
+#include <linux/module.h>
+
+#define MAX_DEV 128
+#define MAX_NAME 32
+
+static uint timeout;
+module_param(timeout, uint, 0444);
+MODULE_PARM_DESC(timeout,
+		 "Default pmc command timeout in micro-seconds.\n");
+
+struct eio_hwmon_dev {
+	struct device *mfd;
+};
+
+enum _sen_type {
+	NONE,
+	VOLTAGE,
+	CURRENT,
+	TEMP,
+	PWM,
+	TACHO,
+	FAN,
+	CASEOPEN,
+};
+
+struct eio_key {
+	enum _sen_type type;
+	u8 chan;
+	u8 item;
+	u8 label_idx;
+};
+
+struct eio_attr {
+	struct sensor_device_attribute sda;
+	struct eio_key key;
+};
+
+static struct {
+	u8   cmd;
+	u8   max;
+	signed int shift;
+	char name[32];
+	u8   ctrl[16];
+	u16  multi[16];
+	char item[16][32];
+	char labels[32][32];
+
+} sen_info[] = {
+	{ 0x00, 0, 0, "none" },
+	{ 0x12, 8, 0, "in",
+		{ 0xFF, 0x10, 0x11, 0x12 },
+		{ 1,    10,   10,   10 },
+		{ "label", "input", "max", "min" },
+		{ "5V", "5Vs5", "12V", "12Vs5",
+		  "3V3", "3V3", "5Vsb", "3Vsb",
+		  "Vcmos", "Vbat", "Vdc", "Vstb",
+		  "Vcore_a", "Vcore_b", "", "",
+		  "Voem0", "Voem1", "Voem2", "Voem3"
+		},
+	},
+	{ 0x1a, 2, 0, "curr",
+		{ 0xFF, 0x10, 0x11, 0x12 },
+		{ 1,    10,   10,   10 },
+		{ "label", "input", "max", "min" },
+		{ "dc", "oem0" },
+	},
+	{ 0x10, 4, -2731, "temp",
+		{ 0xFF, 0x10, 0x11, 0x12, 0x21, 0x41 },
+		{ 1,    100,  100,  100,  100,  100 },
+		{ "label", "input", "max", "min", "crit", "emergency" },
+		{ "cpu0", "cpu1", "cpu2", "cpu3",
+		  "sys0", "sys1", "sys2", "sys3",
+		  "aux0", "aux1", "aux2", "aux3",
+		  "dimm0", "dimm1", "dimm2", "dimm3",
+		  "pch", "gpu", "", "",
+		  "", "", "", "",
+		  "", "", "", "",
+		  "oem0", "oem1", "oem", "oem3" },
+	},
+	{ 0x14, 0, 0, "pwm",
+		{ 0xFF, 0x11, 0x12 },
+		{ 1, 1, 1 },
+		{ "label", "polarity", "freq" },
+		{ "pwm0", "pwm0", "pwm0", "pwm0" },
+	},
+	{ 0x16, 2, 0, "tacho",
+		{ 0xFF, 0x10 },
+		{ 1, 1 },
+		{ "label", "input"},
+		{ "cpu0", "cpu1", "cpu2", "cpu3",
+		  "sys0", "sys1", "sys2", "sys3",
+		  "", "", "", "", "", "", "", "",
+		  "", "", "", "", "", "", "", "",
+		  "", "", "", "",
+		  "oem0", "oem1", "oem2", "oem3"
+		},
+	},
+	{ 0x24, 4, 0, "fan",
+		{ 0xFF, 0x1A },
+		{ 1, 1 },
+		{ "label", "input"},
+		{ "cpu0", "cpu1", "cpu2", "cpu3",
+		  "sys0", "sys1", "sys2", "sys3",
+		  "", "", "", "", "", "", "", "",
+		  "", "", "", "", "", "", "", "",
+		  "", "", "", "",
+		  "oem0", "oem1", "oem2", "oem3",
+		},
+	},
+	{ 0x28, 1, 0, "intrusion",
+		{ 0xFF, 0x02 },
+		{ 1, 1 },
+		{ "label", "input" },
+		{ "case_open" }
+	}
+};
+
+static struct {
+	enum _sen_type type;
+	u8   ctrl;
+	int  size;
+	bool write;
+
+} ctrl_para[] = {
+	{ NONE,     0x00, 0, false },
+
+	{ VOLTAGE,  0x00, 1, false }, { VOLTAGE,  0x01, 1, false },
+	{ VOLTAGE,  0x10, 2, false }, { VOLTAGE,  0x11, 2, false },
+	{ VOLTAGE,  0x12, 2, false },
+
+	{ CURRENT,  0x00, 1, false }, { CURRENT,  0x01, 1, false },
+	{ CURRENT,  0x10, 2, false }, { CURRENT,  0x11, 2, false },
+	{ CURRENT,  0x12, 2, false },
+
+	{ TEMP,	    0x00, 2, false }, { TEMP,	  0x01, 1, false },
+	{ TEMP,     0x04, 1, false }, { TEMP,	  0x10, 2, false },
+	{ TEMP,     0x11, 2, false }, { TEMP,	  0x12, 2, false },
+	{ TEMP,     0x21, 2, false }, { TEMP,	  0x41, 2, false },
+
+	{ PWM,      0x00, 1, false }, { PWM,	  0x10, 1, true  },
+	{ PWM,      0x11, 1, true  }, { PWM,	  0x12, 4, true  },
+
+	{ TACHO,    0x00, 1, false }, { TACHO,	  0x01, 1, false },
+	{ TACHO,    0x10, 4, true  },
+
+	{ FAN,      0x00, 1, false }, { FAN,	  0x01, 1, false },
+	{ FAN,      0x03, 1, true  }, { FAN,	  0x1A, 2, false },
+
+	{ CASEOPEN, 0x00, 1, false }, { CASEOPEN, 0x02, 1, true  },
+};
+
+static int para_idx(enum _sen_type type, u8 ctrl)
+{
+	int i;
+
+	for (i = 1 ; i < ARRAY_SIZE(ctrl_para) ; i++)
+		if (type == ctrl_para[i].type &&
+		    ctrl == ctrl_para[i].ctrl)
+			return i;
+
+	return 0;
+}
+
+static int pmc_read(struct device *mfd, enum _sen_type type, u8 dev_id, u8 ctrl, void *data)
+{
+	int idx = para_idx(type, ctrl);
+	int ret = 0;
+
+	if (idx == 0)
+		return -EINVAL;
+
+	if (WARN_ON(!data))
+		return -EINVAL;
+
+	struct pmc_op op = {
+		 .cmd       = sen_info[type].cmd | EIO_FLAG_PMC_READ,
+		 .control   = ctrl,
+		 .device_id = dev_id,
+		 .size	    = ctrl_para[idx].size,
+		 .payload   = (u8 *)data,
+		 .timeout   = timeout,
+	};
+
+	ret = eio_core_pmc_operation(mfd, &op);
+	return ret;
+}
+
+static ssize_t eio_show(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct eio_hwmon_dev *eio_hwmon = dev_get_drvdata(dev);
+	struct eio_attr *eio_attr =
+		container_of(attr, struct eio_attr, sda.dev_attr);
+	const struct eio_key *eio_key = &eio_attr->key;
+	int ret;
+	u8 data[2];
+	u32 temp_val;
+	signed int final_val;
+
+	switch (eio_key->item) {
+	case 0:
+		return sysfs_emit(buf, "%s\n",
+				  sen_info[eio_key->type].labels[eio_key->label_idx]);
+
+	default:
+		ret = pmc_read(eio_hwmon->mfd, eio_key->type, eio_key->chan,
+			       sen_info[eio_key->type].ctrl[eio_key->item],
+			       &data);
+		if (ret)
+			return ret;
+
+		temp_val = data[0] | data[1] << 8;
+
+		final_val = (signed int)temp_val + (signed int)(sen_info[eio_key->type].shift);
+		final_val = final_val * (signed int)sen_info[eio_key->type].multi[eio_key->item];
+
+		return sysfs_emit(buf, "%d\n", final_val);
+	}
+
+	return -EINVAL;
+}
+
+static char devname[MAX_DEV][MAX_NAME];
+static struct eio_attr devattrs[MAX_DEV];
+static struct attribute *attrs[MAX_DEV];
+
+static struct attribute_group group = {
+	.attrs = attrs,
+};
+
+static const struct attribute_group *groups[] = {
+	&group,
+	NULL
+};
+
+static int hwmon_init(struct device *mfd, struct eio_hwmon_dev *eio_hwmon)
+{
+	enum _sen_type type;
+	u8 i, j, data[16];
+	int sum = 0;
+	int ret;
+
+	for (type = VOLTAGE ; type <= CASEOPEN ; type++) {
+		int cnt = 1;
+
+		for (i = 0 ; i < sen_info[type].max ; i++) {
+			if (pmc_read(mfd, type, i, 0x00, data) ||
+			    (data[0] & 0x01) == 0)
+				continue;
+
+			memset(data, 0, sizeof(data));
+			ret = pmc_read(mfd, type, i, 0x01, data);
+			if (ret != 0 && ret != -EINVAL) {
+				dev_info(mfd, "read type id error\n");
+				continue;
+			}
+
+			for (j = 0 ; j < ARRAY_SIZE(sen_info->item) ; j++) {
+				struct eio_attr *eio_attr;
+
+				if (sen_info[type].item[j][0] == 0)
+					continue;
+
+				eio_attr = &devattrs[sum];
+
+				eio_attr->key.type      = type;
+				eio_attr->key.chan      = i;
+				eio_attr->key.item      = j;
+				eio_attr->key.label_idx = data[0];
+
+				snprintf(devname[sum], sizeof(devname[sum]),
+					 "%s%d_%s", sen_info[type].name, cnt,
+					 sen_info[type].item[j]);
+
+				eio_attr->sda.dev_attr.attr.name = devname[sum];
+				eio_attr->sda.dev_attr.attr.mode = 0444;
+				eio_attr->sda.dev_attr.show      = eio_show;
+
+				attrs[sum] = &eio_attr->sda.dev_attr.attr;
+
+				if (++sum >= MAX_DEV)
+					break;
+			}
+			cnt++;
+		}
+	}
+
+	return sum;
+}
+
+static int hwmon_probe(struct platform_device *pdev)
+{
+	struct device *dev =  &pdev->dev;
+	struct eio_hwmon_dev *eio_hwmon;
+	struct eio_dev *eio_dev = dev_get_drvdata(dev->parent);
+	struct device *hwmon;
+
+	if (!eio_dev) {
+		dev_err(dev, "Error contact eio_core\n");
+		return -ENODEV;
+	}
+
+	eio_hwmon = devm_kzalloc(dev, sizeof(*eio_hwmon), GFP_KERNEL);
+	if (!eio_hwmon)
+		return -ENOMEM;
+
+	eio_hwmon->mfd = dev->parent;
+	platform_set_drvdata(pdev, eio_hwmon);
+
+	if (hwmon_init(dev->parent, eio_hwmon) <= 0)
+		return -ENODEV;
+
+	hwmon =	devm_hwmon_device_register_with_groups(dev, KBUILD_MODNAME,
+						       eio_hwmon,
+						       groups);
+	return PTR_ERR_OR_ZERO(hwmon);
+}
+
+static struct platform_driver eio_hwmon_driver = {
+	.probe  = hwmon_probe,
+	.driver = {
+		.name = "eio_hwmon",
+	},
+};
+
+module_platform_driver(eio_hwmon_driver);
+
+MODULE_AUTHOR("Wenkai Chung <wenkai.chung@advantech.com.tw>");
+MODULE_AUTHOR("Ramiro Oliveira <ramiro.oliveira@advantech.com>");
+MODULE_DESCRIPTION("Hardware monitor driver for Advantech EIO embedded controller");
+MODULE_LICENSE("GPL");
+

-- 
2.43.0