157 lines
3.4 KiB
C
157 lines
3.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* 1-Wire implementation for the ds2781 chip
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*
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* Author: Renata Sayakhova <renata@oktetlabs.ru>
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*
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* Based on w1-ds2780 driver
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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/device.h>
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#include <linux/types.h>
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#include <linux/platform_device.h>
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#include <linux/mutex.h>
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#include <linux/w1.h>
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#include "w1_ds2781.h"
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#define W1_FAMILY_DS2781 0x3D
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static int w1_ds2781_do_io(struct device *dev, char *buf, int addr,
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size_t count, int io)
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{
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struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
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if (addr > DS2781_DATA_SIZE || addr < 0)
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return 0;
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count = min_t(int, count, DS2781_DATA_SIZE - addr);
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if (w1_reset_select_slave(sl) == 0) {
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if (io) {
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w1_write_8(sl->master, W1_DS2781_WRITE_DATA);
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w1_write_8(sl->master, addr);
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w1_write_block(sl->master, buf, count);
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} else {
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w1_write_8(sl->master, W1_DS2781_READ_DATA);
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w1_write_8(sl->master, addr);
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count = w1_read_block(sl->master, buf, count);
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}
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}
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return count;
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}
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int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
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int io)
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{
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struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
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int ret;
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if (!dev)
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return -ENODEV;
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mutex_lock(&sl->master->bus_mutex);
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ret = w1_ds2781_do_io(dev, buf, addr, count, io);
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mutex_unlock(&sl->master->bus_mutex);
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return ret;
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}
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EXPORT_SYMBOL(w1_ds2781_io);
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int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
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{
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struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
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if (!dev)
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return -EINVAL;
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mutex_lock(&sl->master->bus_mutex);
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if (w1_reset_select_slave(sl) == 0) {
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w1_write_8(sl->master, cmd);
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w1_write_8(sl->master, addr);
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}
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mutex_unlock(&sl->master->bus_mutex);
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return 0;
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}
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EXPORT_SYMBOL(w1_ds2781_eeprom_cmd);
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static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr, char *buf,
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loff_t off, size_t count)
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{
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struct device *dev = kobj_to_dev(kobj);
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return w1_ds2781_io(dev, buf, off, count, 0);
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}
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static BIN_ATTR_RO(w1_slave, DS2781_DATA_SIZE);
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static struct bin_attribute *w1_ds2781_bin_attrs[] = {
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&bin_attr_w1_slave,
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NULL,
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};
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static const struct attribute_group w1_ds2781_group = {
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.bin_attrs = w1_ds2781_bin_attrs,
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};
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static const struct attribute_group *w1_ds2781_groups[] = {
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&w1_ds2781_group,
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NULL,
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};
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static int w1_ds2781_add_slave(struct w1_slave *sl)
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{
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int ret;
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struct platform_device *pdev;
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pdev = platform_device_alloc("ds2781-battery", PLATFORM_DEVID_AUTO);
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if (!pdev)
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return -ENOMEM;
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pdev->dev.parent = &sl->dev;
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ret = platform_device_add(pdev);
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if (ret)
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goto pdev_add_failed;
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dev_set_drvdata(&sl->dev, pdev);
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return 0;
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pdev_add_failed:
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platform_device_put(pdev);
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return ret;
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}
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static void w1_ds2781_remove_slave(struct w1_slave *sl)
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{
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struct platform_device *pdev = dev_get_drvdata(&sl->dev);
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platform_device_unregister(pdev);
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}
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static const struct w1_family_ops w1_ds2781_fops = {
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.add_slave = w1_ds2781_add_slave,
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.remove_slave = w1_ds2781_remove_slave,
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.groups = w1_ds2781_groups,
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};
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static struct w1_family w1_ds2781_family = {
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.fid = W1_FAMILY_DS2781,
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.fops = &w1_ds2781_fops,
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};
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module_w1_family(w1_ds2781_family);
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MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
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MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2781));
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