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![Marc Ferland](/assets/img/avatar_default.png)
This driver is currently broken, it does not show the in0_input sysfs file and also returns the following message on startup: hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info(). This patch converts the driver and also cleans up the 'read' function. Signed-off-by: Marc Ferland <ferlandm@amotus.ca> Link: https://lore.kernel.org/r/20220712193504.1374656-1-ferlandm@amotus.ca Signed-off-by: Guenter Roeck <linux@roeck-us.net>
209 lines
4.9 KiB
C
209 lines
4.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* mcp3021.c - driver for Microchip MCP3021 and MCP3221
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*
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* Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc.
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* Author: Mingkai Hu <Mingkai.hu@freescale.com>
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* Reworked by Sven Schuchmann <schuchmann@schleissheimer.de>
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* DT support added by Clemens Gruber <clemens.gruber@pqgruber.com>
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*
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* This driver exports the value of analog input voltage to sysfs, the
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* voltage unit is mV. Through the sysfs interface, lm-sensors tool
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* can also display the input voltage.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/hwmon.h>
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#include <linux/slab.h>
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#include <linux/i2c.h>
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#include <linux/err.h>
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#include <linux/device.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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/* Vdd / reference voltage in millivolt */
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#define MCP3021_VDD_REF_MAX 5500
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#define MCP3021_VDD_REF_MIN 2700
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#define MCP3021_VDD_REF_DEFAULT 3300
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/* output format */
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#define MCP3021_SAR_SHIFT 2
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#define MCP3021_SAR_MASK 0x3ff
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#define MCP3021_OUTPUT_RES 10 /* 10-bit resolution */
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#define MCP3221_SAR_SHIFT 0
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#define MCP3221_SAR_MASK 0xfff
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#define MCP3221_OUTPUT_RES 12 /* 12-bit resolution */
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enum chips {
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mcp3021,
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mcp3221
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};
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/*
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* Client data (each client gets its own)
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*/
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struct mcp3021_data {
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struct i2c_client *client;
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u32 vdd; /* supply and reference voltage in millivolt */
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u16 sar_shift;
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u16 sar_mask;
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u8 output_res;
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};
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static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val)
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{
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return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);
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}
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static int mcp3021_read(struct device *dev, enum hwmon_sensor_types type,
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u32 attr, int channel, long *val)
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{
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struct mcp3021_data *data = dev_get_drvdata(dev);
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struct i2c_client *client = data->client;
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__be16 buf;
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u16 reg;
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int ret;
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if (type != hwmon_in)
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return -EOPNOTSUPP;
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ret = i2c_master_recv(client, (char *)&buf, 2);
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if (ret < 0)
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return ret;
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if (ret != 2)
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return -EIO;
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/* The output code of the MCP3021 is transmitted with MSB first. */
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reg = be16_to_cpu(buf);
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/*
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* The ten-bit output code is composed of the lower 4-bit of the
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* first byte and the upper 6-bit of the second byte.
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*/
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reg = (reg >> data->sar_shift) & data->sar_mask;
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*val = volts_from_reg(data, reg);
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return 0;
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}
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static umode_t mcp3021_is_visible(const void *_data,
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enum hwmon_sensor_types type,
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u32 attr, int channel)
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{
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if (type != hwmon_in)
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return 0;
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if (attr != hwmon_in_input)
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return 0;
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return 0444;
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}
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static const struct hwmon_channel_info *mcp3021_info[] = {
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HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
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NULL
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};
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static const struct hwmon_ops mcp3021_hwmon_ops = {
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.is_visible = mcp3021_is_visible,
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.read = mcp3021_read,
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};
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static const struct hwmon_chip_info mcp3021_chip_info = {
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.ops = &mcp3021_hwmon_ops,
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.info = mcp3021_info,
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};
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static const struct i2c_device_id mcp3021_id[];
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static int mcp3021_probe(struct i2c_client *client)
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{
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struct mcp3021_data *data = NULL;
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struct device_node *np = client->dev.of_node;
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struct device *hwmon_dev;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
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return -ENODEV;
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data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data),
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GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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i2c_set_clientdata(client, data);
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if (np) {
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if (!of_property_read_u32(np, "reference-voltage-microvolt",
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&data->vdd))
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data->vdd /= 1000;
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else
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data->vdd = MCP3021_VDD_REF_DEFAULT;
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} else {
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u32 *pdata = dev_get_platdata(&client->dev);
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if (pdata)
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data->vdd = *pdata;
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else
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data->vdd = MCP3021_VDD_REF_DEFAULT;
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}
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switch (i2c_match_id(mcp3021_id, client)->driver_data) {
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case mcp3021:
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data->sar_shift = MCP3021_SAR_SHIFT;
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data->sar_mask = MCP3021_SAR_MASK;
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data->output_res = MCP3021_OUTPUT_RES;
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break;
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case mcp3221:
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data->sar_shift = MCP3221_SAR_SHIFT;
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data->sar_mask = MCP3221_SAR_MASK;
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data->output_res = MCP3221_OUTPUT_RES;
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break;
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}
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data->client = client;
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if (data->vdd > MCP3021_VDD_REF_MAX || data->vdd < MCP3021_VDD_REF_MIN)
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return -EINVAL;
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hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
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client->name,
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data,
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&mcp3021_chip_info,
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NULL);
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return PTR_ERR_OR_ZERO(hwmon_dev);
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}
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static const struct i2c_device_id mcp3021_id[] = {
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{ "mcp3021", mcp3021 },
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{ "mcp3221", mcp3221 },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, mcp3021_id);
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#ifdef CONFIG_OF
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static const struct of_device_id of_mcp3021_match[] = {
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{ .compatible = "microchip,mcp3021", .data = (void *)mcp3021 },
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{ .compatible = "microchip,mcp3221", .data = (void *)mcp3221 },
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{ }
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};
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MODULE_DEVICE_TABLE(of, of_mcp3021_match);
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#endif
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static struct i2c_driver mcp3021_driver = {
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.driver = {
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.name = "mcp3021",
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.of_match_table = of_match_ptr(of_mcp3021_match),
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},
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.probe_new = mcp3021_probe,
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.id_table = mcp3021_id,
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};
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module_i2c_driver(mcp3021_driver);
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MODULE_AUTHOR("Mingkai Hu <Mingkai.hu@freescale.com>");
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MODULE_DESCRIPTION("Microchip MCP3021/MCP3221 driver");
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MODULE_LICENSE("GPL");
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