linux/drivers/macintosh/windfarm_smu_controls.c
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   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
  35static int smu_supports_new_fans_ops = 1;
  36
  37/*
  38 * SMU fans control object
  39 */
  40
  41static LIST_HEAD(smu_fans);
  42
  43struct 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
  53static 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
 108static 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
 115static 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
 128static 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
 135static 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
 141static 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
 147static 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
 156static 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
 256static 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
 309static 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
 321module_init(smu_controls_init);
 322module_exit(smu_controls_exit);
 323
 324MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
 325MODULE_DESCRIPTION("SMU control objects for PowerMacs thermal control");
 326MODULE_LICENSE("GPL");
 327
 328