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-rw-r--r--drivers/macintosh/windfarm_max6690_sensor.c141
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");