drivers/macintosh/windfarm_smu_controls.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Windfarm PowerMac thermal control. SMU based controls
   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/completion.h>
  17 #include <asm/prom.h>
  18 #include <asm/machdep.h>
  19 #include <asm/io.h>
  20 #include <asm/sections.h>
  21 #include <asm/smu.h>
  22
  23 #include "windfarm.h"
  24
  25 #define VERSION "0.4"
  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 static int smu_supports_new_fans_ops = 1;
  36
  37 /*
  38  * SMU fans control object
  39  */
  40
  41 static LIST_HEAD(smu_fans);
  42
  43 struct smu_fan_control {
  44         struct list_head        link;
  45         int                     fan_type;       /* 0 = rpm, 1 = pwm */
  46         u32                     reg;            /* index in SMU */
  47         s32                     value;          /* current value */
  48         s32                     min, max;       /* min/max values */
  49         struct wf_control       ctrl;
  50 };
  51 #define to_smu_fan(c) container_of(c, struct smu_fan_control, ctrl)
  52
  53 static int smu_set_fan(int pwm, u8 id, u16 value)
  54 {
  55         struct smu_cmd cmd;
  56         u8 buffer[16];
  57         DECLARE_COMPLETION_ONSTACK(comp);
  58         int rc;
  59
  60         /* Fill SMU command structure */
  61         cmd.cmd = SMU_CMD_FAN_COMMAND;
  62
  63         /* The SMU has an "old" and a "new" way of setting the fan speed
  64          * Unfortunately, I found no reliable way to know which one works
  65          * on a given machine model. After some investigations it appears
  66          * that MacOS X just tries the new one, and if it fails fallbacks
  67          * to the old ones ... Ugh.
  68          */
  69  retry:
  70         if (smu_supports_new_fans_ops) {
  71                 buffer[0] = 0x30;
  72                 buffer[1] = id;
  73                 *((u16 *)(&buffer[2])) = value;
  74                 cmd.data_len = 4;
  75         } else {
  76                 if (id > 7)
  77                         return -EINVAL;
  78                 /* Fill argument buffer */
  79                 memset(buffer, 0, 16);
  80                 buffer[0] = pwm ? 0x10 : 0x00;
  81                 buffer[1] = 0x01 << id;
  82                 *((u16 *)&buffer[2 + id * 2]) = value;
  83                 cmd.data_len = 14;
  84         }
  85
  86         cmd.reply_len = 16;
  87         cmd.data_buf = cmd.reply_buf = buffer;
  88         cmd.status = 0;
  89         cmd.done = smu_done_complete;
  90         cmd.misc = &comp;
  91
  92         rc = smu_queue_cmd(&cmd);
  93         if (rc)
  94                 return rc;
  95         wait_for_completion(&comp);
  96
  97         /* Handle fallback (see comment above) */
  98         if (cmd.status != 0 && smu_supports_new_fans_ops) {
  99                 printk(KERN_WARNING "windfarm: SMU failed new fan command "
 100                        "falling back to old method\n");
 101                 smu_supports_new_fans_ops = 0;
 102                 goto retry;
 103         }
 104
 105         return cmd.status;
 106 }
 107
 108 static void smu_fan_release(struct wf_control *ct)
 109 {
 110         struct smu_fan_control *fct = to_smu_fan(ct);
 111
 112         kfree(fct);
 113 }
 114
 115 static int smu_fan_set(struct wf_control *ct, s32 value)
 116 {
 117         struct smu_fan_control *fct = to_smu_fan(ct);
 118
 119         if (value < fct->min)
 120                 value = fct->min;
 121         if (value > fct->max)
 122                 value = fct->max;
 123         fct->value = value;
 124
 125         return smu_set_fan(fct->fan_type, fct->reg, value);
 126 }
 127
 128 static int smu_fan_get(struct wf_control *ct, s32 *value)
 129 {
 130         struct smu_fan_control *fct = to_smu_fan(ct);
 131         *value = fct->value; /* todo: read from SMU */
 132         return 0;
 133 }
 134
 135 static s32 smu_fan_min(struct wf_control *ct)
 136 {
 137         struct smu_fan_control *fct = to_smu_fan(ct);
 138         return fct->min;
 139 }
 140
 141 static s32 smu_fan_max(struct wf_control *ct)
 142 {
 143         struct smu_fan_control *fct = to_smu_fan(ct);
 144         return fct->max;
 145 }
 146
 147 static const struct wf_control_ops smu_fan_ops = {
 148         .set_value      = smu_fan_set,
 149         .get_value      = smu_fan_get,
 150         .get_min        = smu_fan_min,
 151         .get_max        = smu_fan_max,
 152         .release        = smu_fan_release,
 153         .owner          = THIS_MODULE,
 154 };
 155
 156 static struct smu_fan_control *smu_fan_create(struct device_node *node,
 157                                               int pwm_fan)
 158 {
 159         struct smu_fan_control *fct;
 160         const s32 *v;
 161         const u32 *reg;
 162         const char *l;
 163
 164         fct = kmalloc(sizeof(struct smu_fan_control), GFP_KERNEL);
 165         if (fct == NULL)
 166                 return NULL;
 167         fct->ctrl.ops = &smu_fan_ops;
 168         l = of_get_property(node, "location", NULL);
 169         if (l == NULL)
 170                 goto fail;
 171
 172         fct->fan_type = pwm_fan;
 173         fct->ctrl.type = pwm_fan ? WF_CONTROL_PWM_FAN : WF_CONTROL_RPM_FAN;
 174
 175         /* We use the name & location here the same way we do for SMU sensors,
 176          * see the comment in windfarm_smu_sensors.c. The locations are a bit
 177          * less consistent here between the iMac and the desktop models, but
 178          * that is good enough for our needs for now at least.
 179          *
 180          * One problem though is that Apple seem to be inconsistent with case
 181          * and the kernel doesn't have strcasecmp =P
 182          */
 183
 184         fct->ctrl.name = NULL;
 185
 186         /* Names used on desktop models */
 187         if (!strcmp(l, "Rear Fan 0") || !strcmp(l, "Rear Fan") ||
 188             !strcmp(l, "Rear fan 0") || !strcmp(l, "Rear fan") ||
 189             !strcmp(l, "CPU A EXHAUST"))
 190                 fct->ctrl.name = "cpu-rear-fan-0";
 191         else if (!strcmp(l, "Rear Fan 1") || !strcmp(l, "Rear fan 1") ||
 192                  !strcmp(l, "CPU B EXHAUST"))
 193                 fct->ctrl.name = "cpu-rear-fan-1";
 194         else if (!strcmp(l, "Front Fan 0") || !strcmp(l, "Front Fan") ||
 195                  !strcmp(l, "Front fan 0") || !strcmp(l, "Front fan") ||
 196                  !strcmp(l, "CPU A INTAKE"))
 197                 fct->ctrl.name = "cpu-front-fan-0";
 198         else if (!strcmp(l, "Front Fan 1") || !strcmp(l, "Front fan 1") ||
 199                  !strcmp(l, "CPU B INTAKE"))
 200                 fct->ctrl.name = "cpu-front-fan-1";
 201         else if (!strcmp(l, "CPU A PUMP"))
 202                 fct->ctrl.name = "cpu-pump-0";
 203         else if (!strcmp(l, "CPU B PUMP"))
 204                 fct->ctrl.name = "cpu-pump-1";
 205         else if (!strcmp(l, "Slots Fan") || !strcmp(l, "Slots fan") ||
 206                  !strcmp(l, "EXPANSION SLOTS INTAKE"))
 207                 fct->ctrl.name = "slots-fan";
 208         else if (!strcmp(l, "Drive Bay") || !strcmp(l, "Drive bay") ||
 209                  !strcmp(l, "DRIVE BAY A INTAKE"))
 210                 fct->ctrl.name = "drive-bay-fan";
 211         else if (!strcmp(l, "BACKSIDE"))
 212                 fct->ctrl.name = "backside-fan";
 213
 214         /* Names used on iMac models */
 215         if (!strcmp(l, "System Fan") || !strcmp(l, "System fan"))
 216                 fct->ctrl.name = "system-fan";
 217         else if (!strcmp(l, "CPU Fan") || !strcmp(l, "CPU fan"))
 218                 fct->ctrl.name = "cpu-fan";
 219         else if (!strcmp(l, "Hard Drive") || !strcmp(l, "Hard drive"))
 220                 fct->ctrl.name = "drive-bay-fan";
 221         else if (!strcmp(l, "HDD Fan")) /* seen on iMac G5 iSight */
 222                 fct->ctrl.name = "hard-drive-fan";
 223         else if (!strcmp(l, "ODD Fan")) /* same */
 224                 fct->ctrl.name = "optical-drive-fan";
 225
 226         /* Unrecognized fan, bail out */
 227         if (fct->ctrl.name == NULL)
 228                 goto fail;
 229
 230         /* Get min & max values*/
 231         v = of_get_property(node, "min-value", NULL);
 232         if (v == NULL)
 233                 goto fail;
 234         fct->min = *v;
 235         v = of_get_property(node, "max-value", NULL);
 236         if (v == NULL)
 237                 goto fail;
 238         fct->max = *v;
 239
 240         /* Get "reg" value */
 241         reg = of_get_property(node, "reg", NULL);
 242         if (reg == NULL)
 243                 goto fail;
 244         fct->reg = *reg;
 245
 246         if (wf_register_control(&fct->ctrl))
 247                 goto fail;
 248
 249         return fct;
 250  fail:
 251         kfree(fct);
 252         return NULL;
 253 }
 254
 255
 256 static int __init smu_controls_init(void)
 257 {
 258         struct device_node *smu, *fans, *fan;
 259
 260         if (!smu_present())
 261                 return -ENODEV;
 262
 263         smu = of_find_node_by_type(NULL, "smu");
 264         if (smu == NULL)
 265                 return -ENODEV;
 266
 267         /* Look for RPM fans */
 268         for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
 269                 if (of_node_name_eq(fans, "rpm-fans") ||
 270                     of_device_is_compatible(fans, "smu-rpm-fans"))
 271                         break;
 272         for (fan = NULL;
 273              fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
 274                 struct smu_fan_control *fct;
 275
 276                 fct = smu_fan_create(fan, 0);
 277                 if (fct == NULL) {
 278                         printk(KERN_WARNING "windfarm: Failed to create SMU "
 279                                "RPM fan %pOFn\n", fan);
 280                         continue;
 281                 }
 282                 list_add(&fct->link, &smu_fans);
 283         }
 284         of_node_put(fans);
 285
 286
 287         /* Look for PWM fans */
 288         for (fans = NULL; (fans = of_get_next_child(smu, fans)) != NULL;)
 289                 if (of_node_name_eq(fans, "pwm-fans"))
 290                         break;
 291         for (fan = NULL;
 292              fans && (fan = of_get_next_child(fans, fan)) != NULL;) {
 293                 struct smu_fan_control *fct;
 294
 295                 fct = smu_fan_create(fan, 1);
 296                 if (fct == NULL) {
 297                         printk(KERN_WARNING "windfarm: Failed to create SMU "
 298                                "PWM fan %pOFn\n", fan);
 299                         continue;
 300                 }
 301                 list_add(&fct->link, &smu_fans);
 302         }
 303         of_node_put(fans);
 304         of_node_put(smu);
 305
 306         return 0;
 307 }
 308
 309 static void __exit smu_controls_exit(void)
 310 {
 311         struct smu_fan_control *fct;
 312
 313         while (!list_empty(&smu_fans)) {
 314                 fct = list_entry(smu_fans.next, struct smu_fan_control, link);
 315                 list_del(&fct->link);
 316                 wf_unregister_control(&fct->ctrl);
 317         }
 318 }
 319
 320
 321 module_init(smu_controls_init);
 322 module_exit(smu_controls_exit);
 323
 324 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 325 MODULE_DESCRIPTION("SMU control objects for PowerMacs thermal control");
 326 MODULE_LICENSE("GPL");
 327