Benjamin Herrenschmidt | 75722d3 | 2005-11-07 16:08:17 +1100 | [diff] [blame] | 1 | /* |
| 2 | * Windfarm PowerMac thermal control. LM75 sensor |
| 3 | * |
| 4 | * (c) Copyright 2005 Benjamin Herrenschmidt, IBM Corp. |
| 5 | * <benh@kernel.crashing.org> |
| 6 | * |
| 7 | * Released under the term of the GNU GPL v2. |
| 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 <linux/i2c-dev.h> |
| 19 | #include <asm/prom.h> |
| 20 | #include <asm/machdep.h> |
| 21 | #include <asm/io.h> |
| 22 | #include <asm/system.h> |
| 23 | #include <asm/sections.h> |
| 24 | |
| 25 | #include "windfarm.h" |
| 26 | |
| 27 | #define VERSION "0.1" |
| 28 | |
| 29 | #undef DEBUG |
| 30 | |
| 31 | #ifdef DEBUG |
| 32 | #define DBG(args...) printk(args) |
| 33 | #else |
| 34 | #define DBG(args...) do { } while(0) |
| 35 | #endif |
| 36 | |
| 37 | struct wf_lm75_sensor { |
| 38 | int ds1775 : 1; |
| 39 | int inited : 1; |
| 40 | struct i2c_client i2c; |
| 41 | struct wf_sensor sens; |
| 42 | }; |
| 43 | #define wf_to_lm75(c) container_of(c, struct wf_lm75_sensor, sens) |
| 44 | #define i2c_to_lm75(c) container_of(c, struct wf_lm75_sensor, i2c) |
| 45 | |
| 46 | static int wf_lm75_attach(struct i2c_adapter *adapter); |
| 47 | static int wf_lm75_detach(struct i2c_client *client); |
| 48 | |
| 49 | static struct i2c_driver wf_lm75_driver = { |
Laurent Riffard | a33ca23 | 2005-11-26 20:40:34 +0100 | [diff] [blame] | 50 | .driver = { |
Laurent Riffard | a33ca23 | 2005-11-26 20:40:34 +0100 | [diff] [blame] | 51 | .name = "wf_lm75", |
| 52 | }, |
Benjamin Herrenschmidt | 75722d3 | 2005-11-07 16:08:17 +1100 | [diff] [blame] | 53 | .attach_adapter = wf_lm75_attach, |
| 54 | .detach_client = wf_lm75_detach, |
| 55 | }; |
| 56 | |
| 57 | static int wf_lm75_get(struct wf_sensor *sr, s32 *value) |
| 58 | { |
| 59 | struct wf_lm75_sensor *lm = wf_to_lm75(sr); |
| 60 | s32 data; |
| 61 | |
| 62 | if (lm->i2c.adapter == NULL) |
| 63 | return -ENODEV; |
| 64 | |
| 65 | /* Init chip if necessary */ |
| 66 | if (!lm->inited) { |
| 67 | u8 cfg_new, cfg = (u8)i2c_smbus_read_byte_data(&lm->i2c, 1); |
| 68 | |
| 69 | DBG("wf_lm75: Initializing %s, cfg was: %02x\n", |
| 70 | sr->name, cfg); |
| 71 | |
| 72 | /* clear shutdown bit, keep other settings as left by |
| 73 | * the firmware for now |
| 74 | */ |
| 75 | cfg_new = cfg & ~0x01; |
| 76 | i2c_smbus_write_byte_data(&lm->i2c, 1, cfg_new); |
| 77 | lm->inited = 1; |
| 78 | |
| 79 | /* If we just powered it up, let's wait 200 ms */ |
| 80 | msleep(200); |
| 81 | } |
| 82 | |
| 83 | /* Read temperature register */ |
| 84 | data = (s32)le16_to_cpu(i2c_smbus_read_word_data(&lm->i2c, 0)); |
| 85 | data <<= 8; |
| 86 | *value = data; |
| 87 | |
| 88 | return 0; |
| 89 | } |
| 90 | |
| 91 | static void wf_lm75_release(struct wf_sensor *sr) |
| 92 | { |
| 93 | struct wf_lm75_sensor *lm = wf_to_lm75(sr); |
| 94 | |
| 95 | /* check if client is registered and detach from i2c */ |
| 96 | if (lm->i2c.adapter) { |
| 97 | i2c_detach_client(&lm->i2c); |
| 98 | lm->i2c.adapter = NULL; |
| 99 | } |
| 100 | |
| 101 | kfree(lm); |
| 102 | } |
| 103 | |
| 104 | static struct wf_sensor_ops wf_lm75_ops = { |
| 105 | .get_value = wf_lm75_get, |
| 106 | .release = wf_lm75_release, |
| 107 | .owner = THIS_MODULE, |
| 108 | }; |
| 109 | |
| 110 | static struct wf_lm75_sensor *wf_lm75_create(struct i2c_adapter *adapter, |
| 111 | u8 addr, int ds1775, |
| 112 | const char *loc) |
| 113 | { |
| 114 | struct wf_lm75_sensor *lm; |
| 115 | |
| 116 | DBG("wf_lm75: creating %s device at address 0x%02x\n", |
| 117 | ds1775 ? "ds1775" : "lm75", addr); |
| 118 | |
| 119 | lm = kmalloc(sizeof(struct wf_lm75_sensor), GFP_KERNEL); |
| 120 | if (lm == NULL) |
| 121 | return NULL; |
| 122 | memset(lm, 0, sizeof(struct wf_lm75_sensor)); |
| 123 | |
| 124 | /* Usual rant about sensor names not beeing very consistent in |
| 125 | * the device-tree, oh well ... |
| 126 | * Add more entries below as you deal with more setups |
| 127 | */ |
| 128 | if (!strcmp(loc, "Hard drive") || !strcmp(loc, "DRIVE BAY")) |
| 129 | lm->sens.name = "hd-temp"; |
| 130 | else |
| 131 | goto fail; |
| 132 | |
| 133 | lm->inited = 0; |
| 134 | lm->sens.ops = &wf_lm75_ops; |
| 135 | lm->ds1775 = ds1775; |
| 136 | lm->i2c.addr = (addr >> 1) & 0x7f; |
| 137 | lm->i2c.adapter = adapter; |
| 138 | lm->i2c.driver = &wf_lm75_driver; |
| 139 | strncpy(lm->i2c.name, lm->sens.name, I2C_NAME_SIZE-1); |
| 140 | |
| 141 | if (i2c_attach_client(&lm->i2c)) { |
| 142 | printk(KERN_ERR "windfarm: failed to attach %s %s to i2c\n", |
| 143 | ds1775 ? "ds1775" : "lm75", lm->i2c.name); |
| 144 | goto fail; |
| 145 | } |
| 146 | |
| 147 | if (wf_register_sensor(&lm->sens)) { |
| 148 | i2c_detach_client(&lm->i2c); |
| 149 | goto fail; |
| 150 | } |
| 151 | |
| 152 | return lm; |
| 153 | fail: |
| 154 | kfree(lm); |
| 155 | return NULL; |
| 156 | } |
| 157 | |
| 158 | static int wf_lm75_attach(struct i2c_adapter *adapter) |
| 159 | { |
| 160 | u8 bus_id; |
| 161 | struct device_node *smu, *bus, *dev; |
| 162 | |
| 163 | /* We currently only deal with LM75's hanging off the SMU |
| 164 | * i2c busses. If we extend that driver to other/older |
| 165 | * machines, we should split this function into SMU-i2c, |
| 166 | * keywest-i2c, PMU-i2c, ... |
| 167 | */ |
| 168 | |
| 169 | DBG("wf_lm75: adapter %s detected\n", adapter->name); |
| 170 | |
| 171 | if (strncmp(adapter->name, "smu-i2c-", 8) != 0) |
| 172 | return 0; |
| 173 | smu = of_find_node_by_type(NULL, "smu"); |
| 174 | if (smu == NULL) |
| 175 | return 0; |
| 176 | |
| 177 | /* Look for the bus in the device-tree */ |
| 178 | bus_id = (u8)simple_strtoul(adapter->name + 8, NULL, 16); |
| 179 | |
| 180 | DBG("wf_lm75: bus ID is %x\n", bus_id); |
| 181 | |
| 182 | /* Look for sensors subdir */ |
| 183 | for (bus = NULL; |
| 184 | (bus = of_get_next_child(smu, bus)) != NULL;) { |
| 185 | u32 *reg; |
| 186 | |
| 187 | if (strcmp(bus->name, "i2c")) |
| 188 | continue; |
| 189 | reg = (u32 *)get_property(bus, "reg", NULL); |
| 190 | if (reg == NULL) |
| 191 | continue; |
| 192 | if (bus_id == *reg) |
| 193 | break; |
| 194 | } |
| 195 | of_node_put(smu); |
| 196 | if (bus == NULL) { |
| 197 | printk(KERN_WARNING "windfarm: SMU i2c bus 0x%x not found" |
| 198 | " in device-tree !\n", bus_id); |
| 199 | return 0; |
| 200 | } |
| 201 | |
| 202 | DBG("wf_lm75: bus found, looking for device...\n"); |
| 203 | |
| 204 | /* Now look for lm75(s) in there */ |
| 205 | for (dev = NULL; |
| 206 | (dev = of_get_next_child(bus, dev)) != NULL;) { |
| 207 | const char *loc = |
| 208 | get_property(dev, "hwsensor-location", NULL); |
| 209 | u32 *reg = (u32 *)get_property(dev, "reg", NULL); |
| 210 | DBG(" dev: %s... (loc: %p, reg: %p)\n", dev->name, loc, reg); |
| 211 | if (loc == NULL || reg == NULL) |
| 212 | continue; |
| 213 | /* real lm75 */ |
| 214 | if (device_is_compatible(dev, "lm75")) |
| 215 | wf_lm75_create(adapter, *reg, 0, loc); |
| 216 | /* ds1775 (compatible, better resolution */ |
| 217 | else if (device_is_compatible(dev, "ds1775")) |
| 218 | wf_lm75_create(adapter, *reg, 1, loc); |
| 219 | } |
| 220 | |
| 221 | of_node_put(bus); |
| 222 | |
| 223 | return 0; |
| 224 | } |
| 225 | |
| 226 | static int wf_lm75_detach(struct i2c_client *client) |
| 227 | { |
| 228 | struct wf_lm75_sensor *lm = i2c_to_lm75(client); |
| 229 | |
| 230 | DBG("wf_lm75: i2c detatch called for %s\n", lm->sens.name); |
| 231 | |
| 232 | /* Mark client detached */ |
| 233 | lm->i2c.adapter = NULL; |
| 234 | |
| 235 | /* release sensor */ |
| 236 | wf_unregister_sensor(&lm->sens); |
| 237 | |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | static int __init wf_lm75_sensor_init(void) |
| 242 | { |
| 243 | int rc; |
| 244 | |
| 245 | rc = i2c_add_driver(&wf_lm75_driver); |
| 246 | if (rc < 0) |
| 247 | return rc; |
| 248 | return 0; |
| 249 | } |
| 250 | |
| 251 | static void __exit wf_lm75_sensor_exit(void) |
| 252 | { |
| 253 | i2c_del_driver(&wf_lm75_driver); |
| 254 | } |
| 255 | |
| 256 | |
| 257 | module_init(wf_lm75_sensor_init); |
| 258 | module_exit(wf_lm75_sensor_exit); |
| 259 | |
| 260 | MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); |
| 261 | MODULE_DESCRIPTION("LM75 sensor objects for PowerMacs thermal control"); |
| 262 | MODULE_LICENSE("GPL"); |
| 263 | |