^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * mcp3021.c - driver for Microchip MCP3021 and MCP3221
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Author: Mingkai Hu <Mingkai.hu@freescale.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Reworked by Sven Schuchmann <schuchmann@schleissheimer.de>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * DT support added by Clemens Gruber <clemens.gruber@pqgruber.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * This driver export the value of analog input voltage to sysfs, the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * voltage unit is mV. Through the sysfs interface, lm-sensors tool
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * can also display the input voltage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/hwmon.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/i2c.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/err.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/of.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/of_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /* Vdd / reference voltage in millivolt */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #define MCP3021_VDD_REF_MAX 5500
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #define MCP3021_VDD_REF_MIN 2700
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #define MCP3021_VDD_REF_DEFAULT 3300
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) /* output format */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #define MCP3021_SAR_SHIFT 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #define MCP3021_SAR_MASK 0x3ff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #define MCP3021_OUTPUT_RES 10 /* 10-bit resolution */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) #define MCP3221_SAR_SHIFT 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) #define MCP3221_SAR_MASK 0xfff
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #define MCP3221_OUTPUT_RES 12 /* 12-bit resolution */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) enum chips {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) mcp3021,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) mcp3221
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * Client data (each client gets its own)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) struct mcp3021_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) struct device *hwmon_dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) u32 vdd; /* supply and reference voltage in millivolt */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) u16 sar_shift;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) u16 sar_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) u8 output_res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) static int mcp3021_read16(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) struct mcp3021_data *data = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) u16 reg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) __be16 buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) ret = i2c_master_recv(client, (char *)&buf, 2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) if (ret != 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) /* The output code of the MCP3021 is transmitted with MSB first. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) reg = be16_to_cpu(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) * The ten-bit output code is composed of the lower 4-bit of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) * first byte and the upper 6-bit of the second byte.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) reg = (reg >> data->sar_shift) & data->sar_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) return reg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) static ssize_t in0_input_show(struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) struct device_attribute *attr, char *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) struct i2c_client *client = to_i2c_client(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) struct mcp3021_data *data = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) int reg, in_input;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) reg = mcp3021_read16(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (reg < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) return reg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) in_input = volts_from_reg(data, reg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return sprintf(buf, "%d\n", in_input);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) static DEVICE_ATTR_RO(in0_input);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static const struct i2c_device_id mcp3021_id[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) static int mcp3021_probe(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) struct mcp3021_data *data = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) struct device_node *np = client->dev.of_node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) if (!data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) i2c_set_clientdata(client, data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) if (np) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (!of_property_read_u32(np, "reference-voltage-microvolt",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) &data->vdd))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) data->vdd /= 1000;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) data->vdd = MCP3021_VDD_REF_DEFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) u32 *pdata = dev_get_platdata(&client->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) if (pdata)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) data->vdd = *pdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) data->vdd = MCP3021_VDD_REF_DEFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) switch (i2c_match_id(mcp3021_id, client)->driver_data) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) case mcp3021:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) data->sar_shift = MCP3021_SAR_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) data->sar_mask = MCP3021_SAR_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) data->output_res = MCP3021_OUTPUT_RES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) case mcp3221:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) data->sar_shift = MCP3221_SAR_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) data->sar_mask = MCP3221_SAR_MASK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) data->output_res = MCP3221_OUTPUT_RES;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) if (data->vdd > MCP3021_VDD_REF_MAX || data->vdd < MCP3021_VDD_REF_MIN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) data->hwmon_dev = hwmon_device_register(&client->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) if (IS_ERR(data->hwmon_dev)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) err = PTR_ERR(data->hwmon_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) goto exit_remove;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) exit_remove:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) static int mcp3021_remove(struct i2c_client *client)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) struct mcp3021_data *data = i2c_get_clientdata(client);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) hwmon_device_unregister(data->hwmon_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) static const struct i2c_device_id mcp3021_id[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) { "mcp3021", mcp3021 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) { "mcp3221", mcp3221 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) MODULE_DEVICE_TABLE(i2c, mcp3021_id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) #ifdef CONFIG_OF
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) static const struct of_device_id of_mcp3021_match[] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) { .compatible = "microchip,mcp3021", .data = (void *)mcp3021 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) { .compatible = "microchip,mcp3221", .data = (void *)mcp3221 },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) { }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) MODULE_DEVICE_TABLE(of, of_mcp3021_match);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) static struct i2c_driver mcp3021_driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) .driver = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) .name = "mcp3021",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) .of_match_table = of_match_ptr(of_mcp3021_match),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) },
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) .probe_new = mcp3021_probe,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) .remove = mcp3021_remove,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) .id_table = mcp3021_id,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) module_i2c_driver(mcp3021_driver);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) MODULE_AUTHOR("Mingkai Hu <Mingkai.hu@freescale.com>");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) MODULE_DESCRIPTION("Microchip MCP3021/MCP3221 driver");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) MODULE_LICENSE("GPL");
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags