1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Windfarm PowerMac thermal control. LM75 sensor 4 * 5 * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. 6 * <benh@kernel.crashing.org> 7 */ 8 9 #include <linux/types.h> 10 #include <linux/errno.h> 11 #include <linux/kernel.h> 12 #include <linux/delay.h> 13 #include <linux/slab.h> 14 #include <linux/init.h> 15 #include <linux/wait.h> 16 #include <linux/i2c.h> 17 #include <linux/of_device.h> 18 #include <asm/machdep.h> 19 #include <asm/io.h> 20 #include <asm/sections.h> 21 #include <asm/pmac_low_i2c.h> 22 23 #include "windfarm.h" 24 25 #define VERSION "1.0" 26 27 #undef DEBUG 28 29 #ifdef DEBUG 30 #define DBG(args...) printk(args) 31 #else 32 #define DBG(args...) do { } while(0) 33 #endif 34 35 struct wf_lm75_sensor { 36 unsigned int ds1775 : 1; 37 unsigned int inited : 1; 38 struct i2c_client *i2c; 39 struct wf_sensor sens; 40 }; 41 #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens) 42 43 static int wf_lm75_get(struct wf_sensor *sr, s32 *value) 44 { 45 struct wf_lm75_sensor *lm = wf_to_lm75(sr); 46 s32 data; 47 48 if (lm->i2c == NULL) 49 return -ENODEV; 50 51 /* Init chip if necessary */ 52 if (!lm->inited) { 53 u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(lm->i2c, 1); 54 55 DBG("wf_lm75: Initializing %s, cfg was: %02x\n", 56 sr->name, cfg); 57 58 /* clear shutdown bit, keep other settings as left by 59 * the firmware for now 60 */ 61 cfg_new = cfg & ~0x01; 62 i2c_smbus_write_byte_data(lm->i2c, 1, cfg_new); 63 lm->inited = 1; 64 65 /* If we just powered it up, let's wait 200 ms */ 66 msleep(200); 67 } 68 69 /* Read temperature register */ 70 data = (s32)le16_to_cpu(i2c_smbus_read_word_data(lm->i2c, 0)); 71 data <<= 8; 72 *value = data; 73 74 return 0; 75 } 76 77 static void wf_lm75_release(struct wf_sensor *sr) 78 { 79 struct wf_lm75_sensor *lm = wf_to_lm75(sr); 80 81 kfree(lm); 82 } 83 84 static const struct wf_sensor_ops wf_lm75_ops = { 85 .get_value = wf_lm75_get, 86 .release = wf_lm75_release, 87 .owner = THIS_MODULE, 88 }; 89 90 static int wf_lm75_probe(struct i2c_client *client) 91 { 92 const struct i2c_device_id *id = i2c_client_get_device_id(client); 93 struct wf_lm75_sensor *lm; 94 int rc, ds1775; 95 const char *name, *loc; 96 97 if (id) 98 ds1775 = id->driver_data; 99 else 100 ds1775 = !!of_device_get_match_data(&client->dev); 101 102 DBG("wf_lm75: creating %s device at address 0x%02x\n", 103 ds1775 ? "ds1775" : "lm75", client->addr); 104 105 loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL); 106 if (!loc) { 107 dev_warn(&client->dev, "Missing hwsensor-location property!\n"); 108 return -ENXIO; 109 } 110 111 /* Usual rant about sensor names not beeing very consistent in 112 * the device-tree, oh well ... 113 * Add more entries below as you deal with more setups 114 */ 115 if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) 116 name = "hd-temp"; 117 else if (!strcmp(loc, "Incoming Air Temp")) 118 name = "incoming-air-temp"; 119 else if (!strcmp(loc, "ODD Temp")) 120 name = "optical-drive-temp"; 121 else if (!strcmp(loc, "HD Temp")) 122 name = "hard-drive-temp"; 123 else if (!strcmp(loc, "PCI SLOTS")) 124 name = "slots-temp"; 125 else if (!strcmp(loc, "CPU A INLET")) 126 name = "cpu-inlet-temp-0"; 127 else if (!strcmp(loc, "CPU B INLET")) 128 name = "cpu-inlet-temp-1"; 129 else 130 return -ENXIO; 131 132 133 lm = kzalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); 134 if (lm == NULL) 135 return -ENODEV; 136 137 lm->inited = 0; 138 lm->ds1775 = ds1775; 139 lm->i2c = client; 140 lm->sens.name = name; 141 lm->sens.ops = &wf_lm75_ops; 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 void wf_lm75_remove(struct i2c_client *client) 151 { 152 struct wf_lm75_sensor *lm = i2c_get_clientdata(client); 153 154 /* Mark client detached */ 155 lm->i2c = NULL; 156 157 /* release sensor */ 158 wf_unregister_sensor(&lm->sens); 159 } 160 161 static const struct i2c_device_id wf_lm75_id[] = { 162 { "MAC,lm75", 0 }, 163 { "MAC,ds1775", 1 }, 164 { } 165 }; 166 MODULE_DEVICE_TABLE(i2c, wf_lm75_id); 167 168 static const struct of_device_id wf_lm75_of_id[] = { 169 { .compatible = "lm75", .data = (void *)0}, 170 { .compatible = "ds1775", .data = (void *)1 }, 171 { } 172 }; 173 MODULE_DEVICE_TABLE(of, wf_lm75_of_id); 174 175 static struct i2c_driver wf_lm75_driver = { 176 .driver = { 177 .name = "wf_lm75", 178 .of_match_table = wf_lm75_of_id, 179 }, 180 .probe = wf_lm75_probe, 181 .remove = wf_lm75_remove, 182 .id_table = wf_lm75_id, 183 }; 184 185 module_i2c_driver(wf_lm75_driver); 186 187 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 188 MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); 189 MODULE_LICENSE("GPL"); 190 191