Eric Lee / smarc-ti-linux-kernel | Embedian Git Server

Commit 08fe5bc75f8c43042963dee4f33c9c6cb7791b69

Authored by Benjamin Herrenschmidt 2012-04-19 06:16:53 +0800

powerpc/windfarm: Add lm87 sensor

For use by the upcoming windfarm_rm31

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

Showing 1 changed file with 201 additions and 0 deletions Side-by-side Diff

drivers/macintosh/windfarm_lm87_sensor.c

drivers/macintosh/windfarm_lm87_sensor.c

Diff comments View file @ 08fe5bc

	1	+/*
	2	+ * Windfarm PowerMac thermal control. LM87 sensor
	3	+ *
	4	+ * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.
	5	+ *
	6	+ * Released under the term of the GNU GPL v2.
	7	+ *
	8	+ */
	9	+
	10	+#include <linux/types.h>
	11	+#include <linux/errno.h>
	12	+#include <linux/kernel.h>
	13	+#include <linux/delay.h>
	14	+#include <linux/slab.h>
	15	+#include <linux/init.h>
	16	+#include <linux/wait.h>
	17	+#include <linux/i2c.h>
	18	+#include <asm/prom.h>
	19	+#include <asm/machdep.h>
	20	+#include <asm/io.h>
	21	+#include <asm/sections.h>
	22	+#include <asm/pmac_low_i2c.h>
	23	+
	24	+#include "windfarm.h"
	25	+
	26	+#define VERSION "1.0"
	27	+
	28	+#undef DEBUG
	29	+
	30	+#ifdef DEBUG
	31	+#define DBG(args...) printk(args)
	32	+#else
	33	+#define DBG(args...) do { } while(0)
	34	+#endif
	35	+
	36	+struct wf_lm87_sensor {
	37	+ struct i2c_client *i2c;
	38	+ struct wf_sensor sens;
	39	+};
	40	+#define wf_to_lm87(c) container_of(c, struct wf_lm87_sensor, sens)
	41	+
	42	+
	43	+static int wf_lm87_read_reg(struct i2c_client *chip, int reg)
	44	+{
	45	+ int rc, tries = 0;
	46	+ u8 buf;
	47	+
	48	+ for (;;) {
	49	+ /* Set address */
	50	+ buf = (u8)reg;
	51	+ rc = i2c_master_send(chip, &buf, 1);
	52	+ if (rc <= 0)
	53	+ goto error;
	54	+ rc = i2c_master_recv(chip, &buf, 1);
	55	+ if (rc <= 0)
	56	+ goto error;
	57	+ return (int)buf;
	58	+ error:
	59	+ DBG("wf_lm87: Error reading LM87, retrying...\n");
	60	+ if (++tries > 10) {
	61	+ printk(KERN_ERR "wf_lm87: Error reading LM87 !\n");
	62	+ return -EIO;
	63	+ }
	64	+ msleep(10);
	65	+ }
	66	+}
	67	+
	68	+static int wf_lm87_get(struct wf_sensor sr, s32 value)
	69	+{
	70	+ struct wf_lm87_sensor *lm = sr->priv;
	71	+ s32 temp;
	72	+
	73	+ if (lm->i2c == NULL)
	74	+ return -ENODEV;
	75	+
	76	+#define LM87_INT_TEMP 0x27
	77	+
	78	+ /* Read temperature register */
	79	+ temp = wf_lm87_read_reg(lm->i2c, LM87_INT_TEMP);
	80	+ if (temp < 0)
	81	+ return temp;
	82	+ *value = temp << 16;
	83	+
	84	+ return 0;
	85	+}
	86	+
	87	+static void wf_lm87_release(struct wf_sensor *sr)
	88	+{
	89	+ struct wf_lm87_sensor *lm = wf_to_lm87(sr);
	90	+
	91	+ kfree(lm);
	92	+}
	93	+
	94	+static struct wf_sensor_ops wf_lm87_ops = {
	95	+ .get_value = wf_lm87_get,
	96	+ .release = wf_lm87_release,
	97	+ .owner = THIS_MODULE,
	98	+};
	99	+
	100	+static int wf_lm87_probe(struct i2c_client *client,
	101	+ const struct i2c_device_id *id)
	102	+{
	103	+ struct wf_lm87_sensor *lm;
	104	+ const char name = NULL, loc;
	105	+ struct device_node *np = NULL;
	106	+ int rc;
	107	+
	108	+ /*
	109	+ * The lm87 contains a whole pile of sensors, additionally,
	110	+ * the Xserve G5 has several lm87's. However, for now we only
	111	+ * care about the internal temperature sensor
	112	+ */
	113	+ while ((np = of_get_next_child(client->dev.of_node, np)) != NULL) {
	114	+ if (strcmp(np->name, "int-temp"))
	115	+ continue;
	116	+ loc = of_get_property(np, "location", NULL);
	117	+ if (!loc)
	118	+ continue;
	119	+ if (strstr(loc, "DIMM"))
	120	+ name = "dimms-temp";
	121	+ else if (strstr(loc, "Processors"))
	122	+ name = "between-cpus-temp";
	123	+ if (name) {
	124	+ of_node_put(np);
	125	+ break;
	126	+ }
	127	+ }
	128	+ if (!name) {
	129	+ pr_warning("wf_lm87: Unsupported sensor %s\n",
	130	+ client->dev.of_node->full_name);
	131	+ return -ENODEV;
	132	+ }
	133	+
	134	+ lm = kzalloc(sizeof(struct wf_lm87_sensor), GFP_KERNEL);
	135	+ if (lm == NULL)
	136	+ return -ENODEV;
	137	+
	138	+ lm->i2c = client;
	139	+ lm->sens.name = name;
	140	+ lm->sens.ops = &wf_lm87_ops;
	141	+ lm->sens.priv = lm;
	142	+ i2c_set_clientdata(client, lm);
	143	+
	144	+ rc = wf_register_sensor(&lm->sens);
	145	+ if (rc)
	146	+ kfree(lm);
	147	+ return rc;
	148	+}
	149	+
	150	+static int wf_lm87_remove(struct i2c_client *client)
	151	+{
	152	+ struct wf_lm87_sensor *lm = i2c_get_clientdata(client);
	153	+
	154	+ DBG("wf_lm87: i2c detatch called for %s\n", lm->sens.name);
	155	+
	156	+ /* Mark client detached */
	157	+ lm->i2c = NULL;
	158	+
	159	+ /* release sensor */
	160	+ wf_unregister_sensor(&lm->sens);
	161	+
	162	+ return 0;
	163	+}
	164	+
	165	+static const struct i2c_device_id wf_lm87_id[] = {
	166	+ { "MAC,lm87cimt", 0 },
	167	+ { }
	168	+};
	169	+MODULE_DEVICE_TABLE(i2c, wf_lm87_id);
	170	+
	171	+static struct i2c_driver wf_lm87_driver = {
	172	+ .driver = {
	173	+ .name = "wf_lm87",
	174	+ },
	175	+ .probe = wf_lm87_probe,
	176	+ .remove = wf_lm87_remove,
	177	+ .id_table = wf_lm87_id,
	178	+};
	179	+
	180	+static int __init wf_lm87_sensor_init(void)
	181	+{
	182	+ /* We only support this on the Xserve */
	183	+ if (!of_machine_is_compatible("RackMac3,1"))
	184	+ return -ENODEV;
	185	+
	186	+ return i2c_add_driver(&wf_lm87_driver);
	187	+}
	188	+
	189	+static void __exit wf_lm87_sensor_exit(void)
	190	+{
	191	+ i2c_del_driver(&wf_lm87_driver);
	192	+}
	193	+
	194	+
	195	+module_init(wf_lm87_sensor_init);
	196	+module_exit(wf_lm87_sensor_exit);
	197	+
	198	+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
	199	+MODULE_DESCRIPTION("LM87 sensor objects for PowerMacs thermal control");
	200	+MODULE_LICENSE("GPL");