linux/drivers/macintosh/windfarm_smu_sat.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Windfarm PowerMac thermal control.  SMU "satellite" controller sensors.
   4 *
   5 * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
   6 */
   7
   8#include <linux/types.h>
   9#include <linux/errno.h>
  10#include <linux/kernel.h>
  11#include <linux/slab.h>
  12#include <linux/init.h>
  13#include <linux/wait.h>
  14#include <linux/i2c.h>
  15#include <linux/mutex.h>
  16#include <asm/prom.h>
  17#include <asm/smu.h>
  18#include <asm/pmac_low_i2c.h>
  19
  20#include "windfarm.h"
  21
  22#define VERSION "1.0"
  23
  24/* If the cache is older than 800ms we'll refetch it */
  25#define MAX_AGE         msecs_to_jiffies(800)
  26
  27struct wf_sat {
  28        struct kref             ref;
  29        int                     nr;
  30        struct mutex            mutex;
  31        unsigned long           last_read; /* jiffies when cache last updated */
  32        u8                      cache[16];
  33        struct list_head        sensors;
  34        struct i2c_client       *i2c;
  35        struct device_node      *node;
  36};
  37
  38static struct wf_sat *sats[2];
  39
  40struct wf_sat_sensor {
  41        struct list_head        link;
  42        int                     index;
  43        int                     index2;         /* used for power sensors */
  44        int                     shift;
  45        struct wf_sat           *sat;
  46        struct wf_sensor        sens;
  47};
  48
  49#define wf_to_sat(c)    container_of(c, struct wf_sat_sensor, sens)
  50
  51struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
  52                                                  unsigned int *size)
  53{
  54        struct wf_sat *sat;
  55        int err;
  56        unsigned int i, len;
  57        u8 *buf;
  58        u8 data[4];
  59
  60        /* TODO: Add the resulting partition to the device-tree */
  61
  62        if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
  63                return NULL;
  64
  65        err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
  66        if (err) {
  67                printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
  68                return NULL;
  69        }
  70
  71        err = i2c_smbus_read_word_data(sat->i2c, 9);
  72        if (err < 0) {
  73                printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
  74                return NULL;
  75        }
  76        len = err;
  77        if (len == 0) {
  78                printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
  79                return NULL;
  80        }
  81
  82        len = le16_to_cpu(len);
  83        len = (len + 3) & ~3;
  84        buf = kmalloc(len, GFP_KERNEL);
  85        if (buf == NULL)
  86                return NULL;
  87
  88        for (i = 0; i < len; i += 4) {
  89                err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
  90                if (err < 0) {
  91                        printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
  92                               err);
  93                        goto fail;
  94                }
  95                buf[i] = data[1];
  96                buf[i+1] = data[0];
  97                buf[i+2] = data[3];
  98                buf[i+3] = data[2];
  99        }
 100
 101        printk(KERN_DEBUG "sat %d partition %x:", sat_id, id);
 102        print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
 103                       16, 1, buf, len, false);
 104        if (size)
 105                *size = len;
 106        return (struct smu_sdbp_header *) buf;
 107
 108 fail:
 109        kfree(buf);
 110        return NULL;
 111}
 112EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
 113
 114/* refresh the cache */
 115static int wf_sat_read_cache(struct wf_sat *sat)
 116{
 117        int err;
 118
 119        err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
 120        if (err < 0)
 121                return err;
 122        sat->last_read = jiffies;
 123
 124#ifdef LOTSA_DEBUG
 125        {
 126                int i;
 127                printk(KERN_DEBUG "wf_sat_get: data is");
 128                print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
 129                               16, 1, sat->cache, 16, false);
 130        }
 131#endif
 132        return 0;
 133}
 134
 135static int wf_sat_sensor_get(struct wf_sensor *sr, s32 *value)
 136{
 137        struct wf_sat_sensor *sens = wf_to_sat(sr);
 138        struct wf_sat *sat = sens->sat;
 139        int i, err;
 140        s32 val;
 141
 142        if (sat->i2c == NULL)
 143                return -ENODEV;
 144
 145        mutex_lock(&sat->mutex);
 146        if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
 147                err = wf_sat_read_cache(sat);
 148                if (err)
 149                        goto fail;
 150        }
 151
 152        i = sens->index * 2;
 153        val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
 154        if (sens->index2 >= 0) {
 155                i = sens->index2 * 2;
 156                /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
 157                val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
 158        }
 159
 160        *value = val;
 161        err = 0;
 162
 163 fail:
 164        mutex_unlock(&sat->mutex);
 165        return err;
 166}
 167
 168static void wf_sat_release(struct kref *ref)
 169{
 170        struct wf_sat *sat = container_of(ref, struct wf_sat, ref);
 171
 172        if (sat->nr >= 0)
 173                sats[sat->nr] = NULL;
 174        kfree(sat);
 175}
 176
 177static void wf_sat_sensor_release(struct wf_sensor *sr)
 178{
 179        struct wf_sat_sensor *sens = wf_to_sat(sr);
 180        struct wf_sat *sat = sens->sat;
 181
 182        kfree(sens);
 183        kref_put(&sat->ref, wf_sat_release);
 184}
 185
 186static const struct wf_sensor_ops wf_sat_ops = {
 187        .get_value      = wf_sat_sensor_get,
 188        .release        = wf_sat_sensor_release,
 189        .owner          = THIS_MODULE,
 190};
 191
 192static int wf_sat_probe(struct i2c_client *client,
 193                        const struct i2c_device_id *id)
 194{
 195        struct device_node *dev = client->dev.of_node;
 196        struct wf_sat *sat;
 197        struct wf_sat_sensor *sens;
 198        const u32 *reg;
 199        const char *loc;
 200        u8 chip, core;
 201        struct device_node *child;
 202        int shift, cpu, index;
 203        char *name;
 204        int vsens[2], isens[2];
 205
 206        sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
 207        if (sat == NULL)
 208                return -ENOMEM;
 209        sat->nr = -1;
 210        sat->node = of_node_get(dev);
 211        kref_init(&sat->ref);
 212        mutex_init(&sat->mutex);
 213        sat->i2c = client;
 214        INIT_LIST_HEAD(&sat->sensors);
 215        i2c_set_clientdata(client, sat);
 216
 217        vsens[0] = vsens[1] = -1;
 218        isens[0] = isens[1] = -1;
 219        child = NULL;
 220        while ((child = of_get_next_child(dev, child)) != NULL) {
 221                reg = of_get_property(child, "reg", NULL);
 222                loc = of_get_property(child, "location", NULL);
 223                if (reg == NULL || loc == NULL)
 224                        continue;
 225
 226                /* the cooked sensors are between 0x30 and 0x37 */
 227                if (*reg < 0x30 || *reg > 0x37)
 228                        continue;
 229                index = *reg - 0x30;
 230
 231                /* expect location to be CPU [AB][01] ... */
 232                if (strncmp(loc, "CPU ", 4) != 0)
 233                        continue;
 234                chip = loc[4] - 'A';
 235                core = loc[5] - '0';
 236                if (chip > 1 || core > 1) {
 237                        printk(KERN_ERR "wf_sat_create: don't understand "
 238                               "location %s for %pOF\n", loc, child);
 239                        continue;
 240                }
 241                cpu = 2 * chip + core;
 242                if (sat->nr < 0)
 243                        sat->nr = chip;
 244                else if (sat->nr != chip) {
 245                        printk(KERN_ERR "wf_sat_create: can't cope with "
 246                               "multiple CPU chips on one SAT (%s)\n", loc);
 247                        continue;
 248                }
 249
 250                if (of_node_is_type(child, "voltage-sensor")) {
 251                        name = "cpu-voltage";
 252                        shift = 4;
 253                        vsens[core] = index;
 254                } else if (of_node_is_type(child, "current-sensor")) {
 255                        name = "cpu-current";
 256                        shift = 8;
 257                        isens[core] = index;
 258                } else if (of_node_is_type(child, "temp-sensor")) {
 259                        name = "cpu-temp";
 260                        shift = 10;
 261                } else
 262                        continue;       /* hmmm shouldn't happen */
 263
 264                /* the +16 is enough for "cpu-voltage-n" */
 265                sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 266                if (sens == NULL) {
 267                        printk(KERN_ERR "wf_sat_create: couldn't create "
 268                               "%s sensor %d (no memory)\n", name, cpu);
 269                        continue;
 270                }
 271                sens->index = index;
 272                sens->index2 = -1;
 273                sens->shift = shift;
 274                sens->sat = sat;
 275                sens->sens.ops = &wf_sat_ops;
 276                sens->sens.name = (char *) (sens + 1);
 277                snprintf((char *)sens->sens.name, 16, "%s-%d", name, cpu);
 278
 279                if (wf_register_sensor(&sens->sens))
 280                        kfree(sens);
 281                else {
 282                        list_add(&sens->link, &sat->sensors);
 283                        kref_get(&sat->ref);
 284                }
 285        }
 286
 287        /* make the power sensors */
 288        for (core = 0; core < 2; ++core) {
 289                if (vsens[core] < 0 || isens[core] < 0)
 290                        continue;
 291                cpu = 2 * sat->nr + core;
 292                sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
 293                if (sens == NULL) {
 294                        printk(KERN_ERR "wf_sat_create: couldn't create power "
 295                               "sensor %d (no memory)\n", cpu);
 296                        continue;
 297                }
 298                sens->index = vsens[core];
 299                sens->index2 = isens[core];
 300                sens->shift = 0;
 301                sens->sat = sat;
 302                sens->sens.ops = &wf_sat_ops;
 303                sens->sens.name = (char *) (sens + 1);
 304                snprintf((char *)sens->sens.name, 16, "cpu-power-%d", cpu);
 305
 306                if (wf_register_sensor(&sens->sens))
 307                        kfree(sens);
 308                else {
 309                        list_add(&sens->link, &sat->sensors);
 310                        kref_get(&sat->ref);
 311                }
 312        }
 313
 314        if (sat->nr >= 0)
 315                sats[sat->nr] = sat;
 316
 317        return 0;
 318}
 319
 320static int wf_sat_remove(struct i2c_client *client)
 321{
 322        struct wf_sat *sat = i2c_get_clientdata(client);
 323        struct wf_sat_sensor *sens;
 324
 325        /* release sensors */
 326        while(!list_empty(&sat->sensors)) {
 327                sens = list_first_entry(&sat->sensors,
 328                                        struct wf_sat_sensor, link);
 329                list_del(&sens->link);
 330                wf_unregister_sensor(&sens->sens);
 331        }
 332        sat->i2c = NULL;
 333        kref_put(&sat->ref, wf_sat_release);
 334
 335        return 0;
 336}
 337
 338static const struct i2c_device_id wf_sat_id[] = {
 339        { "MAC,smu-sat", 0 },
 340        { }
 341};
 342MODULE_DEVICE_TABLE(i2c, wf_sat_id);
 343
 344static struct i2c_driver wf_sat_driver = {
 345        .driver = {
 346                .name           = "wf_smu_sat",
 347        },
 348        .probe          = wf_sat_probe,
 349        .remove         = wf_sat_remove,
 350        .id_table       = wf_sat_id,
 351};
 352
 353module_i2c_driver(wf_sat_driver);
 354
 355MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
 356MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
 357MODULE_LICENSE("GPL");
 358