w1/slaves/w1_ds2780.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * 1-Wire implementation for the ds2780 chip
0004  *
0005  * Copyright (C) 2010 Indesign, LLC
0006  *
0007  * Author: Clifton Barnes <cabarnes@indesign-llc.com>
0008  *
0009  * Based on w1-ds2760 driver
0010  */
0011
0012 #include <linux/kernel.h>
0013 #include <linux/module.h>
0014 #include <linux/device.h>
0015 #include <linux/types.h>
0016 #include <linux/platform_device.h>
0017 #include <linux/mutex.h>
0018 #include <linux/idr.h>
0019
0020 #include <linux/w1.h>
0021
0022 #include "w1_ds2780.h"
0023
0024 #define W1_FAMILY_DS2780    0x32
0025
0026 static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,
0027             size_t count, int io)
0028 {
0029     struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
0030
0031     if (addr > DS2780_DATA_SIZE || addr < 0)
0032         return 0;
0033
0034     count = min_t(int, count, DS2780_DATA_SIZE - addr);
0035
0036     if (w1_reset_select_slave(sl) == 0) {
0037         if (io) {
0038             w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
0039             w1_write_8(sl->master, addr);
0040             w1_write_block(sl->master, buf, count);
0041         } else {
0042             w1_write_8(sl->master, W1_DS2780_READ_DATA);
0043             w1_write_8(sl->master, addr);
0044             count = w1_read_block(sl->master, buf, count);
0045         }
0046     }
0047
0048     return count;
0049 }
0050
0051 int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
0052             int io)
0053 {
0054     struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
0055     int ret;
0056
0057     if (!dev)
0058         return -ENODEV;
0059
0060     mutex_lock(&sl->master->bus_mutex);
0061
0062     ret = w1_ds2780_do_io(dev, buf, addr, count, io);
0063
0064     mutex_unlock(&sl->master->bus_mutex);
0065
0066     return ret;
0067 }
0068 EXPORT_SYMBOL(w1_ds2780_io);
0069
0070 int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
0071 {
0072     struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
0073
0074     if (!dev)
0075         return -EINVAL;
0076
0077     mutex_lock(&sl->master->bus_mutex);
0078
0079     if (w1_reset_select_slave(sl) == 0) {
0080         w1_write_8(sl->master, cmd);
0081         w1_write_8(sl->master, addr);
0082     }
0083
0084     mutex_unlock(&sl->master->bus_mutex);
0085     return 0;
0086 }
0087 EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
0088
0089 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
0090                  struct bin_attribute *bin_attr, char *buf,
0091                  loff_t off, size_t count)
0092 {
0093     struct device *dev = kobj_to_dev(kobj);
0094     return w1_ds2780_io(dev, buf, off, count, 0);
0095 }
0096
0097 static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
0098
0099 static struct bin_attribute *w1_ds2780_bin_attrs[] = {
0100     &bin_attr_w1_slave,
0101     NULL,
0102 };
0103
0104 static const struct attribute_group w1_ds2780_group = {
0105     .bin_attrs = w1_ds2780_bin_attrs,
0106 };
0107
0108 static const struct attribute_group *w1_ds2780_groups[] = {
0109     &w1_ds2780_group,
0110     NULL,
0111 };
0112
0113 static int w1_ds2780_add_slave(struct w1_slave *sl)
0114 {
0115     int ret;
0116     struct platform_device *pdev;
0117
0118     pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO);
0119     if (!pdev)
0120         return -ENOMEM;
0121     pdev->dev.parent = &sl->dev;
0122
0123     ret = platform_device_add(pdev);
0124     if (ret)
0125         goto pdev_add_failed;
0126
0127     dev_set_drvdata(&sl->dev, pdev);
0128
0129     return 0;
0130
0131 pdev_add_failed:
0132     platform_device_put(pdev);
0133
0134     return ret;
0135 }
0136
0137 static void w1_ds2780_remove_slave(struct w1_slave *sl)
0138 {
0139     struct platform_device *pdev = dev_get_drvdata(&sl->dev);
0140
0141     platform_device_unregister(pdev);
0142 }
0143
0144 static const struct w1_family_ops w1_ds2780_fops = {
0145     .add_slave    = w1_ds2780_add_slave,
0146     .remove_slave = w1_ds2780_remove_slave,
0147     .groups       = w1_ds2780_groups,
0148 };
0149
0150 static struct w1_family w1_ds2780_family = {
0151     .fid = W1_FAMILY_DS2780,
0152     .fops = &w1_ds2780_fops,
0153 };
0154 module_w1_family(w1_ds2780_family);
0155
0156 MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
0157 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
0158 MODULE_LICENSE("GPL");
0159 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));