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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Windfarm PowerMac thermal control. AD7417 sensors4 *5 * Copyright 2012 Benjamin Herrenschmidt, IBM Corp.6 */7 8#include <linux/types.h>9#include <linux/errno.h>10#include <linux/kernel.h>11#include <linux/delay.h>12#include <linux/slab.h>13#include <linux/init.h>14#include <linux/wait.h>15#include <linux/i2c.h>16 17#include <asm/machdep.h>18#include <asm/io.h>19#include <asm/sections.h>20 21#include "windfarm.h"22#include "windfarm_mpu.h"23 24#define VERSION "1.0"25 26struct wf_ad7417_priv {27 struct kref ref;28 struct i2c_client *i2c;29 u8 config;30 u8 cpu;31 const struct mpu_data *mpu;32 struct wf_sensor sensors[5];33 struct mutex lock;34};35 36static int wf_ad7417_temp_get(struct wf_sensor *sr, s32 *value)37{38 struct wf_ad7417_priv *pv = sr->priv;39 u8 buf[2];40 s16 raw;41 int rc;42 43 *value = 0;44 mutex_lock(&pv->lock);45 46 /* Read temp register */47 buf[0] = 0;48 rc = i2c_master_send(pv->i2c, buf, 1);49 if (rc < 0)50 goto error;51 rc = i2c_master_recv(pv->i2c, buf, 2);52 if (rc < 0)53 goto error;54 55 /* Read a a 16-bit signed value */56 raw = be16_to_cpup((__le16 *)buf);57 58 /* Convert 8.8-bit to 16.16 fixed point */59 *value = ((s32)raw) << 8;60 61 mutex_unlock(&pv->lock);62 return 0;63 64error:65 mutex_unlock(&pv->lock);66 return -1;67}68 69/*70 * Scaling factors for the AD7417 ADC converters (except71 * for the CPU diode which is obtained from the EEPROM).72 * Those values are obtained from the property list of73 * the darwin driver74 */75#define ADC_12V_CURRENT_SCALE 0x0320 /* _AD2 */76#define ADC_CPU_VOLTAGE_SCALE 0x00a0 /* _AD3 */77#define ADC_CPU_CURRENT_SCALE 0x1f40 /* _AD4 */78 79static void wf_ad7417_adc_convert(struct wf_ad7417_priv *pv,80 int chan, s32 raw, s32 *value)81{82 switch(chan) {83 case 1: /* Diode */84 *value = (raw * (s32)pv->mpu->mdiode +85 ((s32)pv->mpu->bdiode << 12)) >> 2;86 break;87 case 2: /* 12v current */88 *value = raw * ADC_12V_CURRENT_SCALE;89 break;90 case 3: /* core voltage */91 *value = raw * ADC_CPU_VOLTAGE_SCALE;92 break;93 case 4: /* core current */94 *value = raw * ADC_CPU_CURRENT_SCALE;95 break;96 }97}98 99static int wf_ad7417_adc_get(struct wf_sensor *sr, s32 *value)100{101 struct wf_ad7417_priv *pv = sr->priv;102 int chan = sr - pv->sensors;103 int i, rc;104 u8 buf[2];105 u16 raw;106 107 *value = 0;108 mutex_lock(&pv->lock);109 for (i = 0; i < 10; i++) {110 /* Set channel */111 buf[0] = 1;112 buf[1] = (pv->config & 0x1f) | (chan << 5);113 rc = i2c_master_send(pv->i2c, buf, 2);114 if (rc < 0)115 goto error;116 117 /* Wait for conversion */118 msleep(1);119 120 /* Switch to data register */121 buf[0] = 4;122 rc = i2c_master_send(pv->i2c, buf, 1);123 if (rc < 0)124 goto error;125 126 /* Read result */127 rc = i2c_master_recv(pv->i2c, buf, 2);128 if (rc < 0)129 goto error;130 131 /* Read a a 16-bit signed value */132 raw = be16_to_cpup((__le16 *)buf) >> 6;133 wf_ad7417_adc_convert(pv, chan, raw, value);134 135 dev_vdbg(&pv->i2c->dev, "ADC chan %d [%s]"136 " raw value: 0x%x, conv to: 0x%08x\n",137 chan, sr->name, raw, *value);138 139 mutex_unlock(&pv->lock);140 return 0;141 142 error:143 dev_dbg(&pv->i2c->dev,144 "Error reading ADC, try %d...\n", i);145 if (i < 9)146 msleep(10);147 }148 mutex_unlock(&pv->lock);149 return -1;150}151 152static void wf_ad7417_release(struct kref *ref)153{154 struct wf_ad7417_priv *pv = container_of(ref,155 struct wf_ad7417_priv, ref);156 kfree(pv);157}158 159static void wf_ad7417_sensor_release(struct wf_sensor *sr)160{161 struct wf_ad7417_priv *pv = sr->priv;162 163 kfree(sr->name);164 kref_put(&pv->ref, wf_ad7417_release);165}166 167static const struct wf_sensor_ops wf_ad7417_temp_ops = {168 .get_value = wf_ad7417_temp_get,169 .release = wf_ad7417_sensor_release,170 .owner = THIS_MODULE,171};172 173static const struct wf_sensor_ops wf_ad7417_adc_ops = {174 .get_value = wf_ad7417_adc_get,175 .release = wf_ad7417_sensor_release,176 .owner = THIS_MODULE,177};178 179static void wf_ad7417_add_sensor(struct wf_ad7417_priv *pv,180 int index, const char *name,181 const struct wf_sensor_ops *ops)182{183 pv->sensors[index].name = kasprintf(GFP_KERNEL, "%s-%d", name, pv->cpu);184 pv->sensors[index].priv = pv;185 pv->sensors[index].ops = ops;186 if (!wf_register_sensor(&pv->sensors[index]))187 kref_get(&pv->ref);188}189 190static void wf_ad7417_init_chip(struct wf_ad7417_priv *pv)191{192 int rc;193 u8 buf[2];194 u8 config = 0;195 196 /*197 * Read ADC the configuration register and cache it. We198 * also make sure Config2 contains proper values, I've seen199 * cases where we got stale grabage in there, thus preventing200 * proper reading of conv. values201 */202 203 /* Clear Config2 */204 buf[0] = 5;205 buf[1] = 0;206 i2c_master_send(pv->i2c, buf, 2);207 208 /* Read & cache Config1 */209 buf[0] = 1;210 rc = i2c_master_send(pv->i2c, buf, 1);211 if (rc > 0) {212 rc = i2c_master_recv(pv->i2c, buf, 1);213 if (rc > 0) {214 config = buf[0];215 216 dev_dbg(&pv->i2c->dev, "ADC config reg: %02x\n",217 config);218 219 /* Disable shutdown mode */220 config &= 0xfe;221 buf[0] = 1;222 buf[1] = config;223 rc = i2c_master_send(pv->i2c, buf, 2);224 }225 }226 if (rc <= 0)227 dev_err(&pv->i2c->dev, "Error reading ADC config\n");228 229 pv->config = config;230}231 232static int wf_ad7417_probe(struct i2c_client *client)233{234 struct wf_ad7417_priv *pv;235 const struct mpu_data *mpu;236 const char *loc;237 int cpu_nr;238 239 loc = of_get_property(client->dev.of_node, "hwsensor-location", NULL);240 if (!loc) {241 dev_warn(&client->dev, "Missing hwsensor-location property!\n");242 return -ENXIO;243 }244 245 /*246 * Identify which CPU we belong to by looking at the first entry247 * in the hwsensor-location list248 */249 if (!strncmp(loc, "CPU A", 5))250 cpu_nr = 0;251 else if (!strncmp(loc, "CPU B", 5))252 cpu_nr = 1;253 else {254 pr_err("wf_ad7417: Can't identify location %s\n", loc);255 return -ENXIO;256 }257 mpu = wf_get_mpu(cpu_nr);258 if (!mpu) {259 dev_err(&client->dev, "Failed to retrieve MPU data\n");260 return -ENXIO;261 }262 263 pv = kzalloc(sizeof(struct wf_ad7417_priv), GFP_KERNEL);264 if (pv == NULL)265 return -ENODEV;266 267 kref_init(&pv->ref);268 mutex_init(&pv->lock);269 pv->i2c = client;270 pv->cpu = cpu_nr;271 pv->mpu = mpu;272 dev_set_drvdata(&client->dev, pv);273 274 /* Initialize the chip */275 wf_ad7417_init_chip(pv);276 277 /*278 * We cannot rely on Apple device-tree giving us child279 * node with the names of the individual sensors so we280 * just hard code what we know about them281 */282 wf_ad7417_add_sensor(pv, 0, "cpu-amb-temp", &wf_ad7417_temp_ops);283 wf_ad7417_add_sensor(pv, 1, "cpu-diode-temp", &wf_ad7417_adc_ops);284 wf_ad7417_add_sensor(pv, 2, "cpu-12v-current", &wf_ad7417_adc_ops);285 wf_ad7417_add_sensor(pv, 3, "cpu-voltage", &wf_ad7417_adc_ops);286 wf_ad7417_add_sensor(pv, 4, "cpu-current", &wf_ad7417_adc_ops);287 288 return 0;289}290 291static void wf_ad7417_remove(struct i2c_client *client)292{293 struct wf_ad7417_priv *pv = dev_get_drvdata(&client->dev);294 int i;295 296 /* Mark client detached */297 pv->i2c = NULL;298 299 /* Release sensor */300 for (i = 0; i < 5; i++)301 wf_unregister_sensor(&pv->sensors[i]);302 303 kref_put(&pv->ref, wf_ad7417_release);304}305 306static const struct i2c_device_id wf_ad7417_id[] = {307 { "MAC,ad7417" },308 { }309};310MODULE_DEVICE_TABLE(i2c, wf_ad7417_id);311 312static const struct of_device_id wf_ad7417_of_id[] = {313 { .compatible = "ad7417", },314 { }315};316MODULE_DEVICE_TABLE(of, wf_ad7417_of_id);317 318static struct i2c_driver wf_ad7417_driver = {319 .driver = {320 .name = "wf_ad7417",321 .of_match_table = wf_ad7417_of_id,322 },323 .probe = wf_ad7417_probe,324 .remove = wf_ad7417_remove,325 .id_table = wf_ad7417_id,326};327 328static int wf_ad7417_init(void)329{330 /* This is only supported on these machines */331 if (!of_machine_is_compatible("PowerMac7,2") &&332 !of_machine_is_compatible("PowerMac7,3") &&333 !of_machine_is_compatible("RackMac3,1"))334 return -ENODEV;335 336 return i2c_add_driver(&wf_ad7417_driver);337}338 339static void wf_ad7417_exit(void)340{341 i2c_del_driver(&wf_ad7417_driver);342}343 344module_init(wf_ad7417_init);345module_exit(wf_ad7417_exit);346 347MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");348MODULE_DESCRIPTION("ad7417 sensor driver for PowerMacs");349MODULE_LICENSE("GPL");350 351