Re: [PATCH v2 2/3] drivers: hwmon: Add W83773G driver

From: Guenter Roeck
Date: Tue Nov 07 2017 - 09:33:50 EST

On 11/07/2017 12:27 AM, Lei YU wrote:
Nuvoton W83773G is a hardware monitor IC providing one local
temperature and two remote temperature sensors.

Signed-off-by: Lei YU <mine260309@xxxxxxxxx>
---
v2:
- Rewrite the driver using regmap
- Add offset and update_interval
---
drivers/hwmon/Kconfig | 10 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/w83773g.c | 281 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 292 insertions(+)
create mode 100644 drivers/hwmon/w83773g.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index d654314..11c6248 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1710,6 +1710,16 @@ config SENSORS_VT8231
This driver can also be built as a module. If so, the module
will be called vt8231.
+config SENSORS_W83773G
+ tristate "Nuvoton W83773G"
+ depends on I2C
+ help
+ If you say yes here you get support for the Nuvoton W83773G hardware
+ monitoring chip.
+
+ This driver can also be built as a module. If so, the module
+ will be called w83773g.
+
config SENSORS_W83781D
tristate "Winbond W83781D, W83782D, W83783S, Asus AS99127F"
depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index c84d978..0649ad8 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_SENSORS_ATK0110) += asus_atk0110.o
# asb100, then w83781d go first, as they can override other drivers' addresses.
obj-$(CONFIG_SENSORS_ASB100) += asb100.o
obj-$(CONFIG_SENSORS_W83627HF) += w83627hf.o
+obj-$(CONFIG_SENSORS_W83773G) += w83773g.o
obj-$(CONFIG_SENSORS_W83792D) += w83792d.o
obj-$(CONFIG_SENSORS_W83793) += w83793.o
obj-$(CONFIG_SENSORS_W83795) += w83795.o
diff --git a/drivers/hwmon/w83773g.c b/drivers/hwmon/w83773g.c
new file mode 100644
index 0000000..d352bac
--- /dev/null
+++ b/drivers/hwmon/w83773g.c
@@ -0,0 +1,281 @@
+/*
+ * Copyright (C) 2017 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Driver for the Nuvoton W83773G SMBus temperature sensor IC.
+ * Supported models: W83773G
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = { 0x4c, 0x4d, I2C_CLIENT_END };
+
+/* The W83773 registers */
+#define W83773_CONVERSION_RATE_REG_READ 0x04
+#define W83773_CONVERSION_RATE_REG_WRITE 0x0A
+#define W83773_MANUFACTURER_ID_REG 0xFE
+#define W83773_LOCAL_TEMP 0x00
+
+static const u8 W83773_STATUS[2] = { 0x02, 0x17 };
+
+static const u8 W83773_TEMP_LSB[2] = { 0x10, 0x25 };
+static const u8 W83773_TEMP_MSB[2] = { 0x01, 0x24 };
+
+static const u8 W83773_OFFSET_LSB[2] = { 0x12, 0x16 };
+static const u8 W83773_OFFSET_MSB[2] = { 0x11, 0x15 };
+
+
+/* this is the number of sensors in the device */
+static const struct i2c_device_id w83773_id[] = {
+ { "w83773g" },
+ { }
+};
+
+MODULE_DEVICE_TABLE(i2c, w83773_id);
+
+static const struct of_device_id w83773_of_match[] = {
+ {
+ .compatible = "nuvoton,w83773g"
+ },
+ { },
+};
+MODULE_DEVICE_TABLE(of, w83773_of_match);
+
+static inline int temp_of_local(s8 reg)
+{
+ return reg * 1000;
+}
+
+static inline int temp_of_remote(s8 hb, u8 lb)
+{
+ return (hb << 3 | lb >> 5) * 125;
+}
+
+static ssize_t show_local_temp(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(regmap, sda->index, &regval);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", temp_of_local(regval));
+}
+
+static ssize_t show_remote_temp(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int regval_high;
+ unsigned int regval_low;
+ int ret;
+
+ ret = regmap_read(regmap, W83773_TEMP_MSB[sda->index], &regval_high);
+ ret |= regmap_read(regmap, W83773_TEMP_LSB[sda->index], &regval_low);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", temp_of_remote(regval_high, regval_low));
+}
+
+static ssize_t show_status(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(regmap, W83773_STATUS[sda->index], &regval);
+
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", (u8)regval & 0x04 >> 2);
+}
+
+static ssize_t show_offset(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int regval_high;
+ unsigned int regval_low;
+ int ret;
+
+ ret = regmap_read(regmap, W83773_OFFSET_MSB[sda->index], &regval_high);
+ ret |= regmap_read(regmap, W83773_OFFSET_LSB[sda->index], &regval_low);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%d\n", temp_of_remote(regval_high, regval_low));
+}
+
+static ssize_t set_offset(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
+ struct regmap *regmap = dev_get_drvdata(dev);
+ long val;
+ int ret;
+ int err;
+ u8 high_byte;
+ u8 low_byte;
+
+ err = kstrtol(buf, 10, &val);
+ if (err)
+ return err;
+
+ val = clamp_val(val, -127825, 127825);
+ /* offset value equals to (high_byte << 3 | low_byte >> 5) * 125 */
+ val /= 125;
+ high_byte = val >> 3;
+ low_byte = (val & 0x07) << 5;
+
+ ret = regmap_write(regmap, W83773_OFFSET_MSB[sda->index], high_byte);
+ ret |= regmap_write(regmap, W83773_OFFSET_LSB[sda->index], low_byte);

Please don't do that. The errors, if any, might be different, messing up
the error return.

+
+ if (ret < 0)
+ return ret;
+ return count;
+}
+
+static ssize_t show_update_interval(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned int regval;
+ int ret;
+
+ ret = regmap_read(regmap, W83773_CONVERSION_RATE_REG_READ, &regval);
+ if (ret < 0)
+ return ret;
+
+ return sprintf(buf, "%u\n", 16000 >> regval);
+}
+
+static ssize_t set_update_interval(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct regmap *regmap = dev_get_drvdata(dev);
+ unsigned long val;
+ int ret;
+ int err, rate;
+
+ err = kstrtoul(buf, 10, &val);
+ if (err)
+ return err;
+
+ /*
+ * For valid rates, interval can be calculated as
+ * interval = (1 << (8 - rate)) * 62.5;
+ * Rounded rate is therefore
+ * rate = 8 - __fls(interval * 8 / (62.5 * 7));
+ * Use clamp_val() to avoid overflows, and to ensure valid input
+ * for __fls.
+ */
+ val = clamp_val(val, 62, 16000) * 10;
+ rate = 8 - __fls((val * 8 / (625 * 7)));
+ ret = regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, rate);
+ if (ret < 0)
+ return ret;
+ return count;
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, 0444, show_local_temp, NULL,
+ W83773_LOCAL_TEMP);
+static SENSOR_DEVICE_ATTR(temp2_input, 0444, show_remote_temp, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_fault, 0444, show_status, NULL, 0);
+static SENSOR_DEVICE_ATTR(temp2_offset, 0644, show_offset, set_offset, 0);
+static SENSOR_DEVICE_ATTR(temp3_input, 0444, show_remote_temp, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp3_fault, 0444, show_status, NULL, 1);
+static SENSOR_DEVICE_ATTR(temp3_offset, 0644, show_offset, set_offset, 1);
+static DEVICE_ATTR(update_interval, 0644, show_update_interval,
+ set_update_interval);
+
+static struct attribute *w83773g_attrs[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ &sensor_dev_attr_temp2_input.dev_attr.attr,
+ &sensor_dev_attr_temp2_fault.dev_attr.attr,
+ &sensor_dev_attr_temp2_offset.dev_attr.attr,
+ &sensor_dev_attr_temp3_input.dev_attr.attr,
+ &sensor_dev_attr_temp3_fault.dev_attr.attr,
+ &sensor_dev_attr_temp3_offset.dev_attr.attr,
+ &dev_attr_update_interval.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(w83773g);
+
+static const struct regmap_config w83773g_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+};
+
+static int w83773_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+
+ struct device *dev = &client->dev;
+ struct device *hwmon_dev;
+ struct regmap *regmap;
+ int ret;
+
+ regmap = devm_regmap_init_i2c(client, &w83773g_regmap_config);
+ if (IS_ERR(regmap)) {
+ dev_err(dev, "failed to allocate register map\n");
+ return PTR_ERR(regmap);
+ }
+
+ /* Set the conversion rate to 2 Hz */
+ ret = regmap_write(regmap, W83773_CONVERSION_RATE_REG_WRITE, 0x05);
+ if (ret < 0) {
+ dev_err(&client->dev, "error writing config rate register\n");
+ return ret;
+ }
+
+ i2c_set_clientdata(client, regmap);
+ hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+ regmap, w83773g_groups);

You lost me here. Why did you stop using the new API ?

Guenter

+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static struct i2c_driver w83773_driver = {
+ .class = I2C_CLASS_HWMON,
+ .driver = {
+ .name = "w83773g",
+ .of_match_table = of_match_ptr(w83773_of_match),
+ },
+ .probe = w83773_probe,
+ .id_table = w83773_id,
+ .address_list = normal_i2c,
+};
+
+module_i2c_driver(w83773_driver);
+
+MODULE_AUTHOR("Lei YU <mine260309@xxxxxxxxx>");
+MODULE_DESCRIPTION("W83773G temperature sensor driver");
+MODULE_LICENSE("GPL");