drivers/macintosh/windfarm_smu_sat.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Windfarm PowerMac thermal control.  SMU "satellite" controller sensors.
0004  *
0005  * Copyright (C) 2005 Paul Mackerras, IBM Corp. <paulus@samba.org>
0006  */
0007
0008 #include <linux/types.h>
0009 #include <linux/errno.h>
0010 #include <linux/kernel.h>
0011 #include <linux/slab.h>
0012 #include <linux/init.h>
0013 #include <linux/wait.h>
0014 #include <linux/i2c.h>
0015 #include <linux/mutex.h>
0016
0017 #include <asm/smu.h>
0018 #include <asm/pmac_low_i2c.h>
0019
0020 #include "windfarm.h"
0021
0022 #define VERSION "1.0"
0023
0024 /* If the cache is older than 800ms we'll refetch it */
0025 #define MAX_AGE     msecs_to_jiffies(800)
0026
0027 struct wf_sat {
0028     struct kref     ref;
0029     int         nr;
0030     struct mutex        mutex;
0031     unsigned long       last_read; /* jiffies when cache last updated */
0032     u8          cache[16];
0033     struct list_head    sensors;
0034     struct i2c_client   *i2c;
0035     struct device_node  *node;
0036 };
0037
0038 static struct wf_sat *sats[2];
0039
0040 struct wf_sat_sensor {
0041     struct list_head    link;
0042     int         index;
0043     int         index2;     /* used for power sensors */
0044     int         shift;
0045     struct wf_sat       *sat;
0046     struct wf_sensor    sens;
0047 };
0048
0049 #define wf_to_sat(c)    container_of(c, struct wf_sat_sensor, sens)
0050
0051 struct smu_sdbp_header *smu_sat_get_sdb_partition(unsigned int sat_id, int id,
0052                           unsigned int *size)
0053 {
0054     struct wf_sat *sat;
0055     int err;
0056     unsigned int i, len;
0057     u8 *buf;
0058     u8 data[4];
0059
0060     /* TODO: Add the resulting partition to the device-tree */
0061
0062     if (sat_id > 1 || (sat = sats[sat_id]) == NULL)
0063         return NULL;
0064
0065     err = i2c_smbus_write_word_data(sat->i2c, 8, id << 8);
0066     if (err) {
0067         printk(KERN_ERR "smu_sat_get_sdb_part wr error %d\n", err);
0068         return NULL;
0069     }
0070
0071     err = i2c_smbus_read_word_data(sat->i2c, 9);
0072     if (err < 0) {
0073         printk(KERN_ERR "smu_sat_get_sdb_part rd len error\n");
0074         return NULL;
0075     }
0076     len = err;
0077     if (len == 0) {
0078         printk(KERN_ERR "smu_sat_get_sdb_part no partition %x\n", id);
0079         return NULL;
0080     }
0081
0082     len = le16_to_cpu(len);
0083     len = (len + 3) & ~3;
0084     buf = kmalloc(len, GFP_KERNEL);
0085     if (buf == NULL)
0086         return NULL;
0087
0088     for (i = 0; i < len; i += 4) {
0089         err = i2c_smbus_read_i2c_block_data(sat->i2c, 0xa, 4, data);
0090         if (err < 0) {
0091             printk(KERN_ERR "smu_sat_get_sdb_part rd err %d\n",
0092                    err);
0093             goto fail;
0094         }
0095         buf[i] = data[1];
0096         buf[i+1] = data[0];
0097         buf[i+2] = data[3];
0098         buf[i+3] = data[2];
0099     }
0100
0101     printk(KERN_DEBUG "sat %d partition %x:", sat_id, id);
0102     print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
0103                16, 1, buf, len, false);
0104     if (size)
0105         *size = len;
0106     return (struct smu_sdbp_header *) buf;
0107
0108  fail:
0109     kfree(buf);
0110     return NULL;
0111 }
0112 EXPORT_SYMBOL_GPL(smu_sat_get_sdb_partition);
0113
0114 /* refresh the cache */
0115 static int wf_sat_read_cache(struct wf_sat *sat)
0116 {
0117     int err;
0118
0119     err = i2c_smbus_read_i2c_block_data(sat->i2c, 0x3f, 16, sat->cache);
0120     if (err < 0)
0121         return err;
0122     sat->last_read = jiffies;
0123
0124 #ifdef LOTSA_DEBUG
0125     {
0126         int i;
0127         printk(KERN_DEBUG "wf_sat_get: data is");
0128         print_hex_dump(KERN_DEBUG, "  ", DUMP_PREFIX_OFFSET,
0129                    16, 1, sat->cache, 16, false);
0130     }
0131 #endif
0132     return 0;
0133 }
0134
0135 static int wf_sat_sensor_get(struct wf_sensor *sr, s32 *value)
0136 {
0137     struct wf_sat_sensor *sens = wf_to_sat(sr);
0138     struct wf_sat *sat = sens->sat;
0139     int i, err;
0140     s32 val;
0141
0142     if (sat->i2c == NULL)
0143         return -ENODEV;
0144
0145     mutex_lock(&sat->mutex);
0146     if (time_after(jiffies, (sat->last_read + MAX_AGE))) {
0147         err = wf_sat_read_cache(sat);
0148         if (err)
0149             goto fail;
0150     }
0151
0152     i = sens->index * 2;
0153     val = ((sat->cache[i] << 8) + sat->cache[i+1]) << sens->shift;
0154     if (sens->index2 >= 0) {
0155         i = sens->index2 * 2;
0156         /* 4.12 * 8.8 -> 12.20; shift right 4 to get 16.16 */
0157         val = (val * ((sat->cache[i] << 8) + sat->cache[i+1])) >> 4;
0158     }
0159
0160     *value = val;
0161     err = 0;
0162
0163  fail:
0164     mutex_unlock(&sat->mutex);
0165     return err;
0166 }
0167
0168 static void wf_sat_release(struct kref *ref)
0169 {
0170     struct wf_sat *sat = container_of(ref, struct wf_sat, ref);
0171
0172     if (sat->nr >= 0)
0173         sats[sat->nr] = NULL;
0174     kfree(sat);
0175 }
0176
0177 static void wf_sat_sensor_release(struct wf_sensor *sr)
0178 {
0179     struct wf_sat_sensor *sens = wf_to_sat(sr);
0180     struct wf_sat *sat = sens->sat;
0181
0182     kfree(sens);
0183     kref_put(&sat->ref, wf_sat_release);
0184 }
0185
0186 static const struct wf_sensor_ops wf_sat_ops = {
0187     .get_value  = wf_sat_sensor_get,
0188     .release    = wf_sat_sensor_release,
0189     .owner      = THIS_MODULE,
0190 };
0191
0192 static int wf_sat_probe(struct i2c_client *client,
0193             const struct i2c_device_id *id)
0194 {
0195     struct device_node *dev = client->dev.of_node;
0196     struct wf_sat *sat;
0197     struct wf_sat_sensor *sens;
0198     const u32 *reg;
0199     const char *loc;
0200     u8 chip, core;
0201     struct device_node *child;
0202     int shift, cpu, index;
0203     char *name;
0204     int vsens[2], isens[2];
0205
0206     sat = kzalloc(sizeof(struct wf_sat), GFP_KERNEL);
0207     if (sat == NULL)
0208         return -ENOMEM;
0209     sat->nr = -1;
0210     sat->node = of_node_get(dev);
0211     kref_init(&sat->ref);
0212     mutex_init(&sat->mutex);
0213     sat->i2c = client;
0214     INIT_LIST_HEAD(&sat->sensors);
0215     i2c_set_clientdata(client, sat);
0216
0217     vsens[0] = vsens[1] = -1;
0218     isens[0] = isens[1] = -1;
0219     for_each_child_of_node(dev, child) {
0220         reg = of_get_property(child, "reg", NULL);
0221         loc = of_get_property(child, "location", NULL);
0222         if (reg == NULL || loc == NULL)
0223             continue;
0224
0225         /* the cooked sensors are between 0x30 and 0x37 */
0226         if (*reg < 0x30 || *reg > 0x37)
0227             continue;
0228         index = *reg - 0x30;
0229
0230         /* expect location to be CPU [AB][01] ... */
0231         if (strncmp(loc, "CPU ", 4) != 0)
0232             continue;
0233         chip = loc[4] - 'A';
0234         core = loc[5] - '0';
0235         if (chip > 1 || core > 1) {
0236             printk(KERN_ERR "wf_sat_create: don't understand "
0237                    "location %s for %pOF\n", loc, child);
0238             continue;
0239         }
0240         cpu = 2 * chip + core;
0241         if (sat->nr < 0)
0242             sat->nr = chip;
0243         else if (sat->nr != chip) {
0244             printk(KERN_ERR "wf_sat_create: can't cope with "
0245                    "multiple CPU chips on one SAT (%s)\n", loc);
0246             continue;
0247         }
0248
0249         if (of_node_is_type(child, "voltage-sensor")) {
0250             name = "cpu-voltage";
0251             shift = 4;
0252             vsens[core] = index;
0253         } else if (of_node_is_type(child, "current-sensor")) {
0254             name = "cpu-current";
0255             shift = 8;
0256             isens[core] = index;
0257         } else if (of_node_is_type(child, "temp-sensor")) {
0258             name = "cpu-temp";
0259             shift = 10;
0260         } else
0261             continue;   /* hmmm shouldn't happen */
0262
0263         /* the +16 is enough for "cpu-voltage-n" */
0264         sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
0265         if (sens == NULL) {
0266             printk(KERN_ERR "wf_sat_create: couldn't create "
0267                    "%s sensor %d (no memory)\n", name, cpu);
0268             continue;
0269         }
0270         sens->index = index;
0271         sens->index2 = -1;
0272         sens->shift = shift;
0273         sens->sat = sat;
0274         sens->sens.ops = &wf_sat_ops;
0275         sens->sens.name = (char *) (sens + 1);
0276         snprintf((char *)sens->sens.name, 16, "%s-%d", name, cpu);
0277
0278         if (wf_register_sensor(&sens->sens))
0279             kfree(sens);
0280         else {
0281             list_add(&sens->link, &sat->sensors);
0282             kref_get(&sat->ref);
0283         }
0284     }
0285
0286     /* make the power sensors */
0287     for (core = 0; core < 2; ++core) {
0288         if (vsens[core] < 0 || isens[core] < 0)
0289             continue;
0290         cpu = 2 * sat->nr + core;
0291         sens = kzalloc(sizeof(struct wf_sat_sensor) + 16, GFP_KERNEL);
0292         if (sens == NULL) {
0293             printk(KERN_ERR "wf_sat_create: couldn't create power "
0294                    "sensor %d (no memory)\n", cpu);
0295             continue;
0296         }
0297         sens->index = vsens[core];
0298         sens->index2 = isens[core];
0299         sens->shift = 0;
0300         sens->sat = sat;
0301         sens->sens.ops = &wf_sat_ops;
0302         sens->sens.name = (char *) (sens + 1);
0303         snprintf((char *)sens->sens.name, 16, "cpu-power-%d", cpu);
0304
0305         if (wf_register_sensor(&sens->sens))
0306             kfree(sens);
0307         else {
0308             list_add(&sens->link, &sat->sensors);
0309             kref_get(&sat->ref);
0310         }
0311     }
0312
0313     if (sat->nr >= 0)
0314         sats[sat->nr] = sat;
0315
0316     return 0;
0317 }
0318
0319 static int wf_sat_remove(struct i2c_client *client)
0320 {
0321     struct wf_sat *sat = i2c_get_clientdata(client);
0322     struct wf_sat_sensor *sens;
0323
0324     /* release sensors */
0325     while(!list_empty(&sat->sensors)) {
0326         sens = list_first_entry(&sat->sensors,
0327                     struct wf_sat_sensor, link);
0328         list_del(&sens->link);
0329         wf_unregister_sensor(&sens->sens);
0330     }
0331     sat->i2c = NULL;
0332     kref_put(&sat->ref, wf_sat_release);
0333
0334     return 0;
0335 }
0336
0337 static const struct i2c_device_id wf_sat_id[] = {
0338     { "MAC,smu-sat", 0 },
0339     { }
0340 };
0341 MODULE_DEVICE_TABLE(i2c, wf_sat_id);
0342
0343 static const struct of_device_id wf_sat_of_id[] = {
0344     { .compatible = "smu-sat", },
0345     { }
0346 };
0347 MODULE_DEVICE_TABLE(of, wf_sat_of_id);
0348
0349 static struct i2c_driver wf_sat_driver = {
0350     .driver = {
0351         .name       = "wf_smu_sat",
0352         .of_match_table = wf_sat_of_id,
0353     },
0354     .probe      = wf_sat_probe,
0355     .remove     = wf_sat_remove,
0356     .id_table   = wf_sat_id,
0357 };
0358
0359 module_i2c_driver(wf_sat_driver);
0360
0361 MODULE_AUTHOR("Paul Mackerras <paulus@samba.org>");
0362 MODULE_DESCRIPTION("SMU satellite sensors for PowerMac thermal control");
0363 MODULE_LICENSE("GPL");