1 files changed, 128 insertions, 0 deletions
diff --git a/drivers/power/supply/bq27xxx_battery_hdq.c b/drivers/power/supply/bq27xxx_battery_hdq.c
new file mode 100644
index 000000000..922759ab2
--- /dev/null
+++ b/drivers/power/supply/bq27xxx_battery_hdq.c
@@ -0,0 +1,128 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * BQ27xxx battery monitor HDQ/1-wire driver
+ *
+ * Copyright (C) 2007-2017 Texas Instruments Incorporated - https://www.ti.com/
+ *
+ */
+
+#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/power/bq27xxx_battery.h>
+
+#include <linux/w1.h>
+
+#define W1_FAMILY_BQ27000	0x01
+
+#define HDQ_CMD_READ	(0 << 7)
+#define HDQ_CMD_WRITE	(1 << 7)
+
+static int F_ID;
+module_param(F_ID, int, S_IRUSR);
+MODULE_PARM_DESC(F_ID, "1-wire slave FID for BQ27xxx device");
+
+static int w1_bq27000_read(struct w1_slave *sl, unsigned int reg)
+{
+	u8 val;
+
+	mutex_lock(&sl->master->bus_mutex);
+	w1_write_8(sl->master, HDQ_CMD_READ | reg);
+	val = w1_read_8(sl->master);
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return val;
+}
+
+static int bq27xxx_battery_hdq_read(struct bq27xxx_device_info *di, u8 reg,
+				    bool single)
+{
+	struct w1_slave *sl = dev_to_w1_slave(di->dev);
+	unsigned int timeout = 3;
+	int upper, lower;
+	int temp;
+
+	if (!single) {
+		/*
+		 * Make sure the value has not changed in between reading the
+		 * lower and the upper part
+		 */
+		upper = w1_bq27000_read(sl, reg + 1);
+		do {
+			temp = upper;
+			if (upper < 0)
+				return upper;
+
+			lower = w1_bq27000_read(sl, reg);
+			if (lower < 0)
+				return lower;
+
+			upper = w1_bq27000_read(sl, reg + 1);
+		} while (temp != upper && --timeout);
+
+		if (timeout == 0)
+			return -EIO;
+
+		return (upper << 8) | lower;
+	}
+
+	return w1_bq27000_read(sl, reg);
+}
+
+static int bq27xxx_battery_hdq_add_slave(struct w1_slave *sl)
+{
+	struct bq27xxx_device_info *di;
+
+	di = devm_kzalloc(&sl->dev, sizeof(*di), GFP_KERNEL);
+	if (!di)
+		return -ENOMEM;
+
+	dev_set_drvdata(&sl->dev, di);
+
+	di->dev = &sl->dev;
+	di->chip = BQ27000;
+	di->name = "bq27000-battery";
+	di->bus.read = bq27xxx_battery_hdq_read;
+
+	return bq27xxx_battery_setup(di);
+}
+
+static void bq27xxx_battery_hdq_remove_slave(struct w1_slave *sl)
+{
+	struct bq27xxx_device_info *di = dev_get_drvdata(&sl->dev);
+
+	bq27xxx_battery_teardown(di);
+}
+
+static const struct w1_family_ops bq27xxx_battery_hdq_fops = {
+	.add_slave	= bq27xxx_battery_hdq_add_slave,
+	.remove_slave	= bq27xxx_battery_hdq_remove_slave,
+};
+
+static struct w1_family bq27xxx_battery_hdq_family = {
+	.fid = W1_FAMILY_BQ27000,
+	.fops = &bq27xxx_battery_hdq_fops,
+};
+
+static int __init bq27xxx_battery_hdq_init(void)
+{
+	if (F_ID)
+		bq27xxx_battery_hdq_family.fid = F_ID;
+
+	return w1_register_family(&bq27xxx_battery_hdq_family);
+}
+module_init(bq27xxx_battery_hdq_init);
+
+static void __exit bq27xxx_battery_hdq_exit(void)
+{
+	w1_unregister_family(&bq27xxx_battery_hdq_family);
+}
+module_exit(bq27xxx_battery_hdq_exit);
+
+MODULE_AUTHOR("Texas Instruments Ltd");
+MODULE_DESCRIPTION("BQ27xxx battery monitor HDQ/1-wire driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_BQ27000));