| // 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 int 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); |
| |
| return 0; |
| } |
| |
| 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"); |
| |