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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-04-18 22:16:53 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-04-30 15:37:21 +1000
commit08fe5bc75f8c43042963dee4f33c9c6cb7791b69 (patch)
tree6978a34f299c5b87d60f884c3083b248ffd666f1 /drivers/macintosh
parent850dc32168a9efad1e5fff885eb80db730ca6aa9 (diff)
downloadlinux-08fe5bc75f8c43042963dee4f33c9c6cb7791b69.tar.gz
powerpc/windfarm: Add lm87 sensor
For use by the upcoming windfarm_rm31 Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'drivers/macintosh')
-rw-r--r--drivers/macintosh/windfarm_lm87_sensor.c201
1 files changed, 201 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_lm87_sensor.c b/drivers/macintosh/windfarm_lm87_sensor.c
new file mode 100644
index 00000000000..c071aab79dd
--- /dev/null
+++ b/drivers/macintosh/windfarm_lm87_sensor.c
@@ -0,0 +1,201 @@
+/*
+ * Windfarm PowerMac thermal control. LM87 sensor
+ *
+ * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
+ *
+ * Released under the term of the GNU GPL v2.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/wait.h>
+#include <linux/i2c.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/io.h>
+#include <asm/sections.h>
+#include <asm/pmac_low_i2c.h>
+
+#include "windfarm.h"
+
+#define VERSION "1.0"
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(args...) printk(args)
+#else
+#define DBG(args...) do { } while(0)
+#endif
+
+struct wf_lm87_sensor {
+ struct i2c_client *i2c;
+ struct wf_sensor sens;
+};
+#define wf_to_lm87(c) container_of(c, struct wf_lm87_sensor, sens)
+
+
+static int wf_lm87_read_reg(struct i2c_client *chip, int reg)
+{
+ int rc, tries = 0;
+ u8 buf;
+
+ for (;;) {
+ /* Set address */
+ buf = (u8)reg;
+ rc = i2c_master_send(chip, &buf, 1);
+ if (rc <= 0)
+ goto error;
+ rc = i2c_master_recv(chip, &buf, 1);
+ if (rc <= 0)
+ goto error;
+ return (int)buf;
+ error:
+ DBG("wf_lm87: Error reading LM87, retrying...\n");
+ if (++tries > 10) {
+ printk(KERN_ERR "wf_lm87: Error reading LM87 !\n");
+ return -EIO;
+ }
+ msleep(10);
+ }
+}
+
+static int wf_lm87_get(struct wf_sensor *sr, s32 *value)
+{
+ struct wf_lm87_sensor *lm = sr->priv;
+ s32 temp;
+
+ if (lm->i2c == NULL)
+ return -ENODEV;
+
+#define LM87_INT_TEMP 0x27
+
+ /* Read temperature register */
+ temp = wf_lm87_read_reg(lm->i2c, LM87_INT_TEMP);
+ if (temp < 0)
+ return temp;
+ *value = temp << 16;
+
+ return 0;
+}
+
+static void wf_lm87_release(struct wf_sensor *sr)
+{
+ struct wf_lm87_sensor *lm = wf_to_lm87(sr);
+
+ kfree(lm);
+}
+
+static struct wf_sensor_ops wf_lm87_ops = {
+ .get_value = wf_lm87_get,
+ .release = wf_lm87_release,
+ .owner = THIS_MODULE,
+};
+
+static int wf_lm87_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct wf_lm87_sensor *lm;
+ const char *name = NULL, *loc;
+ struct device_node *np = NULL;
+ int rc;
+
+ /*
+ * The lm87 contains a whole pile of sensors, additionally,
+ * the Xserve G5 has several lm87's. However, for now we only
+ * care about the internal temperature sensor
+ */
+ while ((np = of_get_next_child(client->dev.of_node, np)) != NULL) {
+ if (strcmp(np->name, "int-temp"))
+ continue;
+ loc = of_get_property(np, "location", NULL);
+ if (!loc)
+ continue;
+ if (strstr(loc, "DIMM"))
+ name = "dimms-temp";
+ else if (strstr(loc, "Processors"))
+ name = "between-cpus-temp";
+ if (name) {
+ of_node_put(np);
+ break;
+ }
+ }
+ if (!name) {
+ pr_warning("wf_lm87: Unsupported sensor %s\n",
+ client->dev.of_node->full_name);
+ return -ENODEV;
+ }
+
+ lm = kzalloc(sizeof(struct wf_lm87_sensor), GFP_KERNEL);
+ if (lm == NULL)
+ return -ENODEV;
+
+ lm->i2c = client;
+ lm->sens.name = name;
+ lm->sens.ops = &wf_lm87_ops;
+ lm->sens.priv = lm;
+ i2c_set_clientdata(client, lm);
+
+ rc = wf_register_sensor(&lm->sens);
+ if (rc)
+ kfree(lm);
+ return rc;
+}
+
+static int wf_lm87_remove(struct i2c_client *client)
+{
+ struct wf_lm87_sensor *lm = i2c_get_clientdata(client);
+
+ DBG("wf_lm87: i2c detatch called for %s\n", lm->sens.name);
+
+ /* Mark client detached */
+ lm->i2c = NULL;
+
+ /* release sensor */
+ wf_unregister_sensor(&lm->sens);
+
+ return 0;
+}
+
+static const struct i2c_device_id wf_lm87_id[] = {
+ { "MAC,lm87cimt", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, wf_lm87_id);
+
+static struct i2c_driver wf_lm87_driver = {
+ .driver = {
+ .name = "wf_lm87",
+ },
+ .probe = wf_lm87_probe,
+ .remove = wf_lm87_remove,
+ .id_table = wf_lm87_id,
+};
+
+static int __init wf_lm87_sensor_init(void)
+{
+ /* We only support this on the Xserve */
+ if (!of_machine_is_compatible("RackMac3,1"))
+ return -ENODEV;
+
+ return i2c_add_driver(&wf_lm87_driver);
+}
+
+static void __exit wf_lm87_sensor_exit(void)
+{
+ i2c_del_driver(&wf_lm87_driver);
+}
+
+
+module_init(wf_lm87_sensor_init);
+module_exit(wf_lm87_sensor_exit);
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("LM87 sensor objects for PowerMacs thermal control");
+MODULE_LICENSE("GPL");
+