diff options
Diffstat (limited to 'drivers/macintosh/windfarm_lm87_sensor.c')
| -rw-r--r-- | drivers/macintosh/windfarm_lm87_sensor.c | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/drivers/macintosh/windfarm_lm87_sensor.c b/drivers/macintosh/windfarm_lm87_sensor.c new file mode 100644 index 000000000..40d254633 --- /dev/null +++ b/drivers/macintosh/windfarm_lm87_sensor.c @@ -0,0 +1,202 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Windfarm PowerMac thermal control. LM87 sensor + * + * Copyright 2012 Benjamin Herrenschmidt, IBM Corp. + */ + +#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/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 const 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 + */ + for_each_child_of_node(client->dev.of_node, np) { + if (!of_node_name_eq(np, "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_warn("wf_lm87: Unsupported sensor %pOF\n", + client->dev.of_node); + 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 void wf_lm87_remove(struct i2c_client *client) +{ + struct wf_lm87_sensor *lm = i2c_get_clientdata(client); + + /* Mark client detached */ + lm->i2c = NULL; + + /* release sensor */ + wf_unregister_sensor(&lm->sens); +} + +static const struct i2c_device_id wf_lm87_id[] = { + { "MAC,lm87cimt", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, wf_lm87_id); + +static const struct of_device_id wf_lm87_of_id[] = { + { .compatible = "lm87cimt", }, + { } +}; +MODULE_DEVICE_TABLE(of, wf_lm87_of_id); + +static struct i2c_driver wf_lm87_driver = { + .driver = { + .name = "wf_lm87", + .of_match_table = wf_lm87_of_id, + }, + .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"); + |