1 files changed, 141 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_max6690_sensor.c b/drivers/macintosh/windfarm_max6690_sensor.c
new file mode 100644
index 000000000..c0d404ebc
--- /dev/null
+++ b/drivers/macintosh/windfarm_max6690_sensor.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Windfarm PowerMac thermal control.  MAX6690 sensor.
+ *
+ * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
+ */
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+
+#include <asm/pmac_low_i2c.h>
+
+#include "windfarm.h"
+
+#define VERSION "1.0"
+
+/* This currently only exports the external temperature sensor,
+   since that's all the control loops need. */
+
+/* Some MAX6690 register numbers */
+#define MAX6690_INTERNAL_TEMP	0
+#define MAX6690_EXTERNAL_TEMP	1
+
+struct wf_6690_sensor {
+	struct i2c_client	*i2c;
+	struct wf_sensor	sens;
+};
+
+#define wf_to_6690(x)	container_of((x), struct wf_6690_sensor, sens)
+
+static int wf_max6690_get(struct wf_sensor *sr, s32 *value)
+{
+	struct wf_6690_sensor *max = wf_to_6690(sr);
+	s32 data;
+
+	if (max->i2c == NULL)
+		return -ENODEV;
+
+	/* chip gets initialized by firmware */
+	data = i2c_smbus_read_byte_data(max->i2c, MAX6690_EXTERNAL_TEMP);
+	if (data < 0)
+		return data;
+	*value = data << 16;
+	return 0;
+}
+
+static void wf_max6690_release(struct wf_sensor *sr)
+{
+	struct wf_6690_sensor *max = wf_to_6690(sr);
+
+	kfree(max);
+}
+
+static const struct wf_sensor_ops wf_max6690_ops = {
+	.get_value	= wf_max6690_get,
+	.release	= wf_max6690_release,
+	.owner		= THIS_MODULE,
+};
+
+static int wf_max6690_probe(struct i2c_client *client,
+			    const struct i2c_device_id *id)
+{
+	const char *name, *loc;
+	struct wf_6690_sensor *max;
+	int rc;
+
+	loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);
+	if (!loc) {
+		dev_warn(&client->dev, "Missing hwsensor-location property!\n");
+		return -ENXIO;
+	}
+
+	/*
+	 * We only expose the external temperature register for
+	 * now as this is all we need for our control loops
+	 */
+	if (!strcmp(loc, "BACKSIDE") || !strcmp(loc, "SYS CTRLR AMBIENT"))
+		name = "backside-temp";
+	else if (!strcmp(loc, "NB Ambient"))
+		name = "north-bridge-temp";
+	else if (!strcmp(loc, "GPU Ambient"))
+		name = "gpu-temp";
+	else
+		return -ENXIO;
+
+	max = kzalloc(sizeof(struct wf_6690_sensor), GFP_KERNEL);
+	if (max == NULL) {
+		printk(KERN_ERR "windfarm: Couldn't create MAX6690 sensor: "
+		       "no memory\n");
+		return -ENOMEM;
+	}
+
+	max->i2c = client;
+	max->sens.name = name;
+	max->sens.ops = &wf_max6690_ops;
+	i2c_set_clientdata(client, max);
+
+	rc = wf_register_sensor(&max->sens);
+	if (rc)
+		kfree(max);
+	return rc;
+}
+
+static void wf_max6690_remove(struct i2c_client *client)
+{
+	struct wf_6690_sensor *max = i2c_get_clientdata(client);
+
+	max->i2c = NULL;
+	wf_unregister_sensor(&max->sens);
+}
+
+static const struct i2c_device_id wf_max6690_id[] = {
+	{ "MAC,max6690", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, wf_max6690_id);
+
+static const struct of_device_id wf_max6690_of_id[] = {
+	{ .compatible = "max6690", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, wf_max6690_of_id);
+
+static struct i2c_driver wf_max6690_driver = {
+	.driver = {
+		.name		= "wf_max6690",
+		.of_match_table = wf_max6690_of_id,
+	},
+	.probe		= wf_max6690_probe,
+	.remove		= wf_max6690_remove,
+	.id_table	= wf_max6690_id,
+};
+
+module_i2c_driver(wf_max6690_driver);
+
+MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
+MODULE_DESCRIPTION("MAX6690 sensor objects for PowerMac thermal control");
+MODULE_LICENSE("GPL");