1 files changed, 156 insertions, 0 deletions

diff --git a/drivers/w1/slaves/w1_ds2781.c b/drivers/w1/slaves/w1_ds2781.c
new file mode 100644
index 000000000..f0d393ae0
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2781.c
@@ -0,0 +1,156 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 1-Wire implementation for the ds2781 chip
+ *
+ * Author: Renata Sayakhova <renata@oktetlabs.ru>
+ *
+ * Based on w1-ds2780 driver
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+
+#include <linux/w1.h>
+
+#include "w1_ds2781.h"
+
+#define W1_FAMILY_DS2781	0x3D
+
+static int w1_ds2781_do_io(struct device *dev, char *buf, int addr,
+			size_t count, int io)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+	if (addr > DS2781_DATA_SIZE || addr < 0)
+		return 0;
+
+	count = min_t(int, count, DS2781_DATA_SIZE - addr);
+
+	if (w1_reset_select_slave(sl) == 0) {
+		if (io) {
+			w1_write_8(sl->master, W1_DS2781_WRITE_DATA);
+			w1_write_8(sl->master, addr);
+			w1_write_block(sl->master, buf, count);
+		} else {
+			w1_write_8(sl->master, W1_DS2781_READ_DATA);
+			w1_write_8(sl->master, addr);
+			count = w1_read_block(sl->master, buf, count);
+		}
+	}
+
+	return count;
+}
+
+int w1_ds2781_io(struct device *dev, char *buf, int addr, size_t count,
+			int io)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+	int ret;
+
+	if (!dev)
+		return -ENODEV;
+
+	mutex_lock(&sl->master->bus_mutex);
+
+	ret = w1_ds2781_do_io(dev, buf, addr, count, io);
+
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL(w1_ds2781_io);
+
+int w1_ds2781_eeprom_cmd(struct device *dev, int addr, int cmd)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+	if (!dev)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+
+	if (w1_reset_select_slave(sl) == 0) {
+		w1_write_8(sl->master, cmd);
+		w1_write_8(sl->master, addr);
+	}
+
+	mutex_unlock(&sl->master->bus_mutex);
+	return 0;
+}
+EXPORT_SYMBOL(w1_ds2781_eeprom_cmd);
+
+static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
+			     struct bin_attribute *bin_attr, char *buf,
+			     loff_t off, size_t count)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	return w1_ds2781_io(dev, buf, off, count, 0);
+}
+
+static BIN_ATTR_RO(w1_slave, DS2781_DATA_SIZE);
+
+static struct bin_attribute *w1_ds2781_bin_attrs[] = {
+	&bin_attr_w1_slave,
+	NULL,
+};
+
+static const struct attribute_group w1_ds2781_group = {
+	.bin_attrs = w1_ds2781_bin_attrs,
+};
+
+static const struct attribute_group *w1_ds2781_groups[] = {
+	&w1_ds2781_group,
+	NULL,
+};
+
+static int w1_ds2781_add_slave(struct w1_slave *sl)
+{
+	int ret;
+	struct platform_device *pdev;
+
+	pdev = platform_device_alloc("ds2781-battery", PLATFORM_DEVID_AUTO);
+	if (!pdev)
+		return -ENOMEM;
+	pdev->dev.parent = &sl->dev;
+
+	ret = platform_device_add(pdev);
+	if (ret)
+		goto pdev_add_failed;
+
+	dev_set_drvdata(&sl->dev, pdev);
+
+	return 0;
+
+pdev_add_failed:
+	platform_device_put(pdev);
+
+	return ret;
+}
+
+static void w1_ds2781_remove_slave(struct w1_slave *sl)
+{
+	struct platform_device *pdev = dev_get_drvdata(&sl->dev);
+
+	platform_device_unregister(pdev);
+}
+
+static const struct w1_family_ops w1_ds2781_fops = {
+	.add_slave    = w1_ds2781_add_slave,
+	.remove_slave = w1_ds2781_remove_slave,
+	.groups       = w1_ds2781_groups,
+};
+
+static struct w1_family w1_ds2781_family = {
+	.fid = W1_FAMILY_DS2781,
+	.fops = &w1_ds2781_fops,
+};
+module_w1_family(w1_ds2781_family);
+
+MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
+MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2781));