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0001 /*
0002  * Driver for batteries with DS2760 chips inside.
0003  *
0004  * Copyright © 2007 Anton Vorontsov
0005  *         2004-2007 Matt Reimer
0006  *         2004 Szabolcs Gyurko
0007  *
0008  * Use consistent with the GNU GPL is permitted,
0009  * provided that this copyright notice is
0010  * preserved in its entirety in all copies and derived works.
0011  *
0012  * Author:  Anton Vorontsov <cbou@mail.ru>
0013  *      February 2007
0014  *
0015  *      Matt Reimer <mreimer@vpop.net>
0016  *      April 2004, 2005, 2007
0017  *
0018  *      Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
0019  *      September 2004
0020  */
0021 
0022 #include <linux/module.h>
0023 #include <linux/param.h>
0024 #include <linux/jiffies.h>
0025 #include <linux/workqueue.h>
0026 #include <linux/pm.h>
0027 #include <linux/slab.h>
0028 #include <linux/platform_device.h>
0029 #include <linux/power_supply.h>
0030 #include <linux/suspend.h>
0031 #include <linux/w1.h>
0032 #include <linux/of.h>
0033 
0034 static unsigned int cache_time = 1000;
0035 module_param(cache_time, uint, 0644);
0036 MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
0037 
0038 static bool pmod_enabled;
0039 module_param(pmod_enabled, bool, 0644);
0040 MODULE_PARM_DESC(pmod_enabled, "PMOD enable bit");
0041 
0042 static unsigned int rated_capacity;
0043 module_param(rated_capacity, uint, 0644);
0044 MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
0045 
0046 static unsigned int current_accum;
0047 module_param(current_accum, uint, 0644);
0048 MODULE_PARM_DESC(current_accum, "current accumulator value");
0049 
0050 #define W1_FAMILY_DS2760        0x30
0051 
0052 /* Known commands to the DS2760 chip */
0053 #define W1_DS2760_SWAP          0xAA
0054 #define W1_DS2760_READ_DATA     0x69
0055 #define W1_DS2760_WRITE_DATA        0x6C
0056 #define W1_DS2760_COPY_DATA     0x48
0057 #define W1_DS2760_RECALL_DATA       0xB8
0058 #define W1_DS2760_LOCK          0x6A
0059 
0060 /* Number of valid register addresses */
0061 #define DS2760_DATA_SIZE        0x40
0062 
0063 #define DS2760_PROTECTION_REG       0x00
0064 
0065 #define DS2760_STATUS_REG       0x01
0066 #define DS2760_STATUS_IE        (1 << 2)
0067 #define DS2760_STATUS_SWEN      (1 << 3)
0068 #define DS2760_STATUS_RNAOP     (1 << 4)
0069 #define DS2760_STATUS_PMOD      (1 << 5)
0070 
0071 #define DS2760_EEPROM_REG       0x07
0072 #define DS2760_SPECIAL_FEATURE_REG  0x08
0073 #define DS2760_VOLTAGE_MSB      0x0c
0074 #define DS2760_VOLTAGE_LSB      0x0d
0075 #define DS2760_CURRENT_MSB      0x0e
0076 #define DS2760_CURRENT_LSB      0x0f
0077 #define DS2760_CURRENT_ACCUM_MSB    0x10
0078 #define DS2760_CURRENT_ACCUM_LSB    0x11
0079 #define DS2760_TEMP_MSB         0x18
0080 #define DS2760_TEMP_LSB         0x19
0081 #define DS2760_EEPROM_BLOCK0        0x20
0082 #define DS2760_ACTIVE_FULL      0x20
0083 #define DS2760_EEPROM_BLOCK1        0x30
0084 #define DS2760_STATUS_WRITE_REG     0x31
0085 #define DS2760_RATED_CAPACITY       0x32
0086 #define DS2760_CURRENT_OFFSET_BIAS  0x33
0087 #define DS2760_ACTIVE_EMPTY     0x3b
0088 
0089 struct ds2760_device_info {
0090     struct device *dev;
0091 
0092     /* DS2760 data, valid after calling ds2760_battery_read_status() */
0093     unsigned long update_time;  /* jiffies when data read */
0094     char raw[DS2760_DATA_SIZE]; /* raw DS2760 data */
0095     int voltage_raw;        /* units of 4.88 mV */
0096     int voltage_uV;         /* units of µV */
0097     int current_raw;        /* units of 0.625 mA */
0098     int current_uA;         /* units of µA */
0099     int accum_current_raw;      /* units of 0.25 mAh */
0100     int accum_current_uAh;      /* units of µAh */
0101     int temp_raw;           /* units of 0.125 °C */
0102     int temp_C;         /* units of 0.1 °C */
0103     int rated_capacity;     /* units of µAh */
0104     int rem_capacity;       /* percentage */
0105     int full_active_uAh;        /* units of µAh */
0106     int empty_uAh;          /* units of µAh */
0107     int life_sec;           /* units of seconds */
0108     int charge_status;      /* POWER_SUPPLY_STATUS_* */
0109 
0110     int full_counter;
0111     struct power_supply *bat;
0112     struct power_supply_desc bat_desc;
0113     struct workqueue_struct *monitor_wqueue;
0114     struct delayed_work monitor_work;
0115     struct delayed_work set_charged_work;
0116     struct notifier_block pm_notifier;
0117 };
0118 
0119 static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
0120             int io)
0121 {
0122     struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
0123 
0124     if (!dev)
0125         return 0;
0126 
0127     mutex_lock(&sl->master->bus_mutex);
0128 
0129     if (addr > DS2760_DATA_SIZE || addr < 0) {
0130         count = 0;
0131         goto out;
0132     }
0133     if (addr + count > DS2760_DATA_SIZE)
0134         count = DS2760_DATA_SIZE - addr;
0135 
0136     if (!w1_reset_select_slave(sl)) {
0137         if (!io) {
0138             w1_write_8(sl->master, W1_DS2760_READ_DATA);
0139             w1_write_8(sl->master, addr);
0140             count = w1_read_block(sl->master, buf, count);
0141         } else {
0142             w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
0143             w1_write_8(sl->master, addr);
0144             w1_write_block(sl->master, buf, count);
0145             /* XXX w1_write_block returns void, not n_written */
0146         }
0147     }
0148 
0149 out:
0150     mutex_unlock(&sl->master->bus_mutex);
0151 
0152     return count;
0153 }
0154 
0155 static int w1_ds2760_read(struct device *dev,
0156               char *buf, int addr,
0157               size_t count)
0158 {
0159     return w1_ds2760_io(dev, buf, addr, count, 0);
0160 }
0161 
0162 static int w1_ds2760_write(struct device *dev,
0163                char *buf,
0164                int addr, size_t count)
0165 {
0166     return w1_ds2760_io(dev, buf, addr, count, 1);
0167 }
0168 
0169 static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
0170 {
0171     struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
0172 
0173     if (!dev)
0174         return -EINVAL;
0175 
0176     mutex_lock(&sl->master->bus_mutex);
0177 
0178     if (w1_reset_select_slave(sl) == 0) {
0179         w1_write_8(sl->master, cmd);
0180         w1_write_8(sl->master, addr);
0181     }
0182 
0183     mutex_unlock(&sl->master->bus_mutex);
0184     return 0;
0185 }
0186 
0187 static int w1_ds2760_store_eeprom(struct device *dev, int addr)
0188 {
0189     return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
0190 }
0191 
0192 static int w1_ds2760_recall_eeprom(struct device *dev, int addr)
0193 {
0194     return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
0195 }
0196 
0197 static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,
0198                  struct bin_attribute *bin_attr, char *buf,
0199                  loff_t off, size_t count)
0200 {
0201     struct device *dev = kobj_to_dev(kobj);
0202     return w1_ds2760_read(dev, buf, off, count);
0203 }
0204 
0205 static BIN_ATTR_RO(w1_slave, DS2760_DATA_SIZE);
0206 
0207 static struct bin_attribute *w1_ds2760_bin_attrs[] = {
0208     &bin_attr_w1_slave,
0209     NULL,
0210 };
0211 
0212 static const struct attribute_group w1_ds2760_group = {
0213     .bin_attrs = w1_ds2760_bin_attrs,
0214 };
0215 
0216 static const struct attribute_group *w1_ds2760_groups[] = {
0217     &w1_ds2760_group,
0218     NULL,
0219 };
0220 /* Some batteries have their rated capacity stored a N * 10 mAh, while
0221  * others use an index into this table. */
0222 static int rated_capacities[] = {
0223     0,
0224     920,    /* Samsung */
0225     920,    /* BYD */
0226     920,    /* Lishen */
0227     920,    /* NEC */
0228     1440,   /* Samsung */
0229     1440,   /* BYD */
0230 #ifdef CONFIG_MACH_H4700
0231     1800,   /* HP iPAQ hx4700 3.7V 1800mAh (359113-001) */
0232 #else
0233     1440,   /* Lishen */
0234 #endif
0235     1440,   /* NEC */
0236     2880,   /* Samsung */
0237     2880,   /* BYD */
0238     2880,   /* Lishen */
0239     2880,   /* NEC */
0240 #ifdef CONFIG_MACH_H4700
0241     0,
0242     3600,   /* HP iPAQ hx4700 3.7V 3600mAh (359114-001) */
0243 #endif
0244 };
0245 
0246 /* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
0247  * temp is in Celsius */
0248 static int battery_interpolate(int array[], int temp)
0249 {
0250     int index, dt;
0251 
0252     if (temp <= 0)
0253         return array[0];
0254     if (temp >= 40)
0255         return array[4];
0256 
0257     index = temp / 10;
0258     dt    = temp % 10;
0259 
0260     return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
0261 }
0262 
0263 static int ds2760_battery_read_status(struct ds2760_device_info *di)
0264 {
0265     int ret, i, start, count, scale[5];
0266 
0267     if (di->update_time && time_before(jiffies, di->update_time +
0268                        msecs_to_jiffies(cache_time)))
0269         return 0;
0270 
0271     /* The first time we read the entire contents of SRAM/EEPROM,
0272      * but after that we just read the interesting bits that change. */
0273     if (di->update_time == 0) {
0274         start = 0;
0275         count = DS2760_DATA_SIZE;
0276     } else {
0277         start = DS2760_VOLTAGE_MSB;
0278         count = DS2760_TEMP_LSB - start + 1;
0279     }
0280 
0281     ret = w1_ds2760_read(di->dev, di->raw + start, start, count);
0282     if (ret != count) {
0283         dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
0284              di->dev);
0285         return 1;
0286     }
0287 
0288     di->update_time = jiffies;
0289 
0290     /* DS2760 reports voltage in units of 4.88mV, but the battery class
0291      * reports in units of uV, so convert by multiplying by 4880. */
0292     di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
0293               (di->raw[DS2760_VOLTAGE_LSB] >> 5);
0294     di->voltage_uV = di->voltage_raw * 4880;
0295 
0296     /* DS2760 reports current in signed units of 0.625mA, but the battery
0297      * class reports in units of µA, so convert by multiplying by 625. */
0298     di->current_raw =
0299         (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
0300               (di->raw[DS2760_CURRENT_LSB] >> 3);
0301     di->current_uA = di->current_raw * 625;
0302 
0303     /* DS2760 reports accumulated current in signed units of 0.25mAh. */
0304     di->accum_current_raw =
0305         (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
0306                di->raw[DS2760_CURRENT_ACCUM_LSB];
0307     di->accum_current_uAh = di->accum_current_raw * 250;
0308 
0309     /* DS2760 reports temperature in signed units of 0.125°C, but the
0310      * battery class reports in units of 1/10 °C, so we convert by
0311      * multiplying by .125 * 10 = 1.25. */
0312     di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
0313                      (di->raw[DS2760_TEMP_LSB] >> 5);
0314     di->temp_C = di->temp_raw + (di->temp_raw / 4);
0315 
0316     /* At least some battery monitors (e.g. HP iPAQ) store the battery's
0317      * maximum rated capacity. */
0318     if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
0319         di->rated_capacity = rated_capacities[
0320             (unsigned int)di->raw[DS2760_RATED_CAPACITY]];
0321     else
0322         di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
0323 
0324     di->rated_capacity *= 1000; /* convert to µAh */
0325 
0326     /* Calculate the full level at the present temperature. */
0327     di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
0328                   di->raw[DS2760_ACTIVE_FULL + 1];
0329 
0330     /* If the full_active_uAh value is not given, fall back to the rated
0331      * capacity. This is likely to happen when chips are not part of the
0332      * battery pack and is therefore not bootstrapped. */
0333     if (di->full_active_uAh == 0)
0334         di->full_active_uAh = di->rated_capacity / 1000L;
0335 
0336     scale[0] = di->full_active_uAh;
0337     for (i = 1; i < 5; i++)
0338         scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 1 + i];
0339 
0340     di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
0341     di->full_active_uAh *= 1000; /* convert to µAh */
0342 
0343     /* Calculate the empty level at the present temperature. */
0344     scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
0345     for (i = 3; i >= 0; i--)
0346         scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
0347 
0348     di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
0349     di->empty_uAh *= 1000; /* convert to µAh */
0350 
0351     if (di->full_active_uAh == di->empty_uAh)
0352         di->rem_capacity = 0;
0353     else
0354         /* From Maxim Application Note 131: remaining capacity =
0355          * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
0356         di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
0357                     (di->full_active_uAh - di->empty_uAh);
0358 
0359     if (di->rem_capacity < 0)
0360         di->rem_capacity = 0;
0361     if (di->rem_capacity > 100)
0362         di->rem_capacity = 100;
0363 
0364     if (di->current_uA < -100L)
0365         di->life_sec = -((di->accum_current_uAh - di->empty_uAh) * 36L)
0366                     / (di->current_uA / 100L);
0367     else
0368         di->life_sec = 0;
0369 
0370     return 0;
0371 }
0372 
0373 static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
0374                          unsigned int acr_val)
0375 {
0376     unsigned char acr[2];
0377 
0378     /* acr is in units of 0.25 mAh */
0379     acr_val *= 4L;
0380     acr_val /= 1000;
0381 
0382     acr[0] = acr_val >> 8;
0383     acr[1] = acr_val & 0xff;
0384 
0385     if (w1_ds2760_write(di->dev, acr, DS2760_CURRENT_ACCUM_MSB, 2) < 2)
0386         dev_warn(di->dev, "ACR write failed\n");
0387 }
0388 
0389 static void ds2760_battery_update_status(struct ds2760_device_info *di)
0390 {
0391     int old_charge_status = di->charge_status;
0392 
0393     ds2760_battery_read_status(di);
0394 
0395     if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
0396         di->full_counter = 0;
0397 
0398     if (power_supply_am_i_supplied(di->bat)) {
0399         if (di->current_uA > 10000) {
0400             di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
0401             di->full_counter = 0;
0402         } else if (di->current_uA < -5000) {
0403             if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
0404                 dev_notice(di->dev, "not enough power to "
0405                        "charge\n");
0406             di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
0407             di->full_counter = 0;
0408         } else if (di->current_uA < 10000 &&
0409                 di->charge_status != POWER_SUPPLY_STATUS_FULL) {
0410 
0411             /* Don't consider the battery to be full unless
0412              * we've seen the current < 10 mA at least two
0413              * consecutive times. */
0414 
0415             di->full_counter++;
0416 
0417             if (di->full_counter < 2) {
0418                 di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
0419             } else {
0420                 di->charge_status = POWER_SUPPLY_STATUS_FULL;
0421                 ds2760_battery_set_current_accum(di,
0422                         di->full_active_uAh);
0423             }
0424         }
0425     } else {
0426         di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
0427         di->full_counter = 0;
0428     }
0429 
0430     if (di->charge_status != old_charge_status)
0431         power_supply_changed(di->bat);
0432 }
0433 
0434 static void ds2760_battery_write_status(struct ds2760_device_info *di,
0435                     char status)
0436 {
0437     if (status == di->raw[DS2760_STATUS_REG])
0438         return;
0439 
0440     w1_ds2760_write(di->dev, &status, DS2760_STATUS_WRITE_REG, 1);
0441     w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
0442     w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
0443 }
0444 
0445 static void ds2760_battery_write_rated_capacity(struct ds2760_device_info *di,
0446                         unsigned char rated_capacity)
0447 {
0448     if (rated_capacity == di->raw[DS2760_RATED_CAPACITY])
0449         return;
0450 
0451     w1_ds2760_write(di->dev, &rated_capacity, DS2760_RATED_CAPACITY, 1);
0452     w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
0453     w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
0454 }
0455 
0456 static void ds2760_battery_write_active_full(struct ds2760_device_info *di,
0457                          int active_full)
0458 {
0459     unsigned char tmp[2] = {
0460         active_full >> 8,
0461         active_full & 0xff
0462     };
0463 
0464     if (tmp[0] == di->raw[DS2760_ACTIVE_FULL] &&
0465         tmp[1] == di->raw[DS2760_ACTIVE_FULL + 1])
0466         return;
0467 
0468     w1_ds2760_write(di->dev, tmp, DS2760_ACTIVE_FULL, sizeof(tmp));
0469     w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK0);
0470     w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK0);
0471 
0472     /* Write to the di->raw[] buffer directly - the DS2760_ACTIVE_FULL
0473      * values won't be read back by ds2760_battery_read_status() */
0474     di->raw[DS2760_ACTIVE_FULL] = tmp[0];
0475     di->raw[DS2760_ACTIVE_FULL + 1] = tmp[1];
0476 }
0477 
0478 static void ds2760_battery_work(struct work_struct *work)
0479 {
0480     struct ds2760_device_info *di = container_of(work,
0481         struct ds2760_device_info, monitor_work.work);
0482     const int interval = HZ * 60;
0483 
0484     dev_dbg(di->dev, "%s\n", __func__);
0485 
0486     ds2760_battery_update_status(di);
0487     queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
0488 }
0489 
0490 static void ds2760_battery_external_power_changed(struct power_supply *psy)
0491 {
0492     struct ds2760_device_info *di = power_supply_get_drvdata(psy);
0493 
0494     dev_dbg(di->dev, "%s\n", __func__);
0495 
0496     mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
0497 }
0498 
0499 
0500 static void ds2760_battery_set_charged_work(struct work_struct *work)
0501 {
0502     char bias;
0503     struct ds2760_device_info *di = container_of(work,
0504         struct ds2760_device_info, set_charged_work.work);
0505 
0506     dev_dbg(di->dev, "%s\n", __func__);
0507 
0508     ds2760_battery_read_status(di);
0509 
0510     /* When we get notified by external circuitry that the battery is
0511      * considered fully charged now, we know that there is no current
0512      * flow any more. However, the ds2760's internal current meter is
0513      * too inaccurate to rely on - spec say something ~15% failure.
0514      * Hence, we use the current offset bias register to compensate
0515      * that error.
0516      */
0517 
0518     if (!power_supply_am_i_supplied(di->bat))
0519         return;
0520 
0521     bias = (signed char) di->current_raw +
0522         (signed char) di->raw[DS2760_CURRENT_OFFSET_BIAS];
0523 
0524     dev_dbg(di->dev, "%s: bias = %d\n", __func__, bias);
0525 
0526     w1_ds2760_write(di->dev, &bias, DS2760_CURRENT_OFFSET_BIAS, 1);
0527     w1_ds2760_store_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
0528     w1_ds2760_recall_eeprom(di->dev, DS2760_EEPROM_BLOCK1);
0529 
0530     /* Write to the di->raw[] buffer directly - the CURRENT_OFFSET_BIAS
0531      * value won't be read back by ds2760_battery_read_status() */
0532     di->raw[DS2760_CURRENT_OFFSET_BIAS] = bias;
0533 }
0534 
0535 static void ds2760_battery_set_charged(struct power_supply *psy)
0536 {
0537     struct ds2760_device_info *di = power_supply_get_drvdata(psy);
0538 
0539     /* postpone the actual work by 20 secs. This is for debouncing GPIO
0540      * signals and to let the current value settle. See AN4188. */
0541     mod_delayed_work(di->monitor_wqueue, &di->set_charged_work, HZ * 20);
0542 }
0543 
0544 static int ds2760_battery_get_property(struct power_supply *psy,
0545                        enum power_supply_property psp,
0546                        union power_supply_propval *val)
0547 {
0548     struct ds2760_device_info *di = power_supply_get_drvdata(psy);
0549 
0550     switch (psp) {
0551     case POWER_SUPPLY_PROP_STATUS:
0552         val->intval = di->charge_status;
0553         return 0;
0554     default:
0555         break;
0556     }
0557 
0558     ds2760_battery_read_status(di);
0559 
0560     switch (psp) {
0561     case POWER_SUPPLY_PROP_VOLTAGE_NOW:
0562         val->intval = di->voltage_uV;
0563         break;
0564     case POWER_SUPPLY_PROP_CURRENT_NOW:
0565         val->intval = di->current_uA;
0566         break;
0567     case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
0568         val->intval = di->rated_capacity;
0569         break;
0570     case POWER_SUPPLY_PROP_CHARGE_FULL:
0571         val->intval = di->full_active_uAh;
0572         break;
0573     case POWER_SUPPLY_PROP_CHARGE_EMPTY:
0574         val->intval = di->empty_uAh;
0575         break;
0576     case POWER_SUPPLY_PROP_CHARGE_NOW:
0577         val->intval = di->accum_current_uAh;
0578         break;
0579     case POWER_SUPPLY_PROP_TEMP:
0580         val->intval = di->temp_C;
0581         break;
0582     case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
0583         val->intval = di->life_sec;
0584         break;
0585     case POWER_SUPPLY_PROP_CAPACITY:
0586         val->intval = di->rem_capacity;
0587         break;
0588     default:
0589         return -EINVAL;
0590     }
0591 
0592     return 0;
0593 }
0594 
0595 static int ds2760_battery_set_property(struct power_supply *psy,
0596                        enum power_supply_property psp,
0597                        const union power_supply_propval *val)
0598 {
0599     struct ds2760_device_info *di = power_supply_get_drvdata(psy);
0600 
0601     switch (psp) {
0602     case POWER_SUPPLY_PROP_CHARGE_FULL:
0603         /* the interface counts in uAh, convert the value */
0604         ds2760_battery_write_active_full(di, val->intval / 1000L);
0605         break;
0606 
0607     case POWER_SUPPLY_PROP_CHARGE_NOW:
0608         /* ds2760_battery_set_current_accum() does the conversion */
0609         ds2760_battery_set_current_accum(di, val->intval);
0610         break;
0611 
0612     default:
0613         return -EPERM;
0614     }
0615 
0616     return 0;
0617 }
0618 
0619 static int ds2760_battery_property_is_writeable(struct power_supply *psy,
0620                         enum power_supply_property psp)
0621 {
0622     switch (psp) {
0623     case POWER_SUPPLY_PROP_CHARGE_FULL:
0624     case POWER_SUPPLY_PROP_CHARGE_NOW:
0625         return 1;
0626 
0627     default:
0628         break;
0629     }
0630 
0631     return 0;
0632 }
0633 
0634 static enum power_supply_property ds2760_battery_props[] = {
0635     POWER_SUPPLY_PROP_STATUS,
0636     POWER_SUPPLY_PROP_VOLTAGE_NOW,
0637     POWER_SUPPLY_PROP_CURRENT_NOW,
0638     POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
0639     POWER_SUPPLY_PROP_CHARGE_FULL,
0640     POWER_SUPPLY_PROP_CHARGE_EMPTY,
0641     POWER_SUPPLY_PROP_CHARGE_NOW,
0642     POWER_SUPPLY_PROP_TEMP,
0643     POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
0644     POWER_SUPPLY_PROP_CAPACITY,
0645 };
0646 
0647 static int ds2760_pm_notifier(struct notifier_block *notifier,
0648                   unsigned long pm_event,
0649                   void *unused)
0650 {
0651     struct ds2760_device_info *di =
0652         container_of(notifier, struct ds2760_device_info, pm_notifier);
0653 
0654     switch (pm_event) {
0655     case PM_HIBERNATION_PREPARE:
0656     case PM_SUSPEND_PREPARE:
0657         di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
0658         break;
0659 
0660     case PM_POST_RESTORE:
0661     case PM_POST_HIBERNATION:
0662     case PM_POST_SUSPEND:
0663         di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
0664         power_supply_changed(di->bat);
0665         mod_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
0666 
0667         break;
0668 
0669     case PM_RESTORE_PREPARE:
0670     default:
0671         break;
0672     }
0673 
0674     return NOTIFY_DONE;
0675 }
0676 
0677 static int w1_ds2760_add_slave(struct w1_slave *sl)
0678 {
0679     struct power_supply_config psy_cfg = {};
0680     struct ds2760_device_info *di;
0681     struct device *dev = &sl->dev;
0682     int retval = 0;
0683     char name[32];
0684     char status;
0685 
0686     di = devm_kzalloc(dev, sizeof(*di), GFP_KERNEL);
0687     if (!di) {
0688         retval = -ENOMEM;
0689         goto di_alloc_failed;
0690     }
0691 
0692     snprintf(name, sizeof(name), "ds2760-battery.%d", dev->id);
0693 
0694     di->dev             = dev;
0695     di->bat_desc.name       = name;
0696     di->bat_desc.type       = POWER_SUPPLY_TYPE_BATTERY;
0697     di->bat_desc.properties     = ds2760_battery_props;
0698     di->bat_desc.num_properties = ARRAY_SIZE(ds2760_battery_props);
0699     di->bat_desc.get_property   = ds2760_battery_get_property;
0700     di->bat_desc.set_property   = ds2760_battery_set_property;
0701     di->bat_desc.property_is_writeable =
0702                   ds2760_battery_property_is_writeable;
0703     di->bat_desc.set_charged    = ds2760_battery_set_charged;
0704     di->bat_desc.external_power_changed =
0705                   ds2760_battery_external_power_changed;
0706 
0707     psy_cfg.drv_data = di;
0708 
0709     if (dev->of_node) {
0710         u32 tmp;
0711 
0712         psy_cfg.of_node = dev->of_node;
0713 
0714         if (!of_property_read_bool(dev->of_node, "maxim,pmod-enabled"))
0715             pmod_enabled = true;
0716 
0717         if (!of_property_read_u32(dev->of_node,
0718                       "maxim,cache-time-ms", &tmp))
0719             cache_time = tmp;
0720 
0721         if (!of_property_read_u32(dev->of_node,
0722                       "rated-capacity-microamp-hours",
0723                       &tmp))
0724             rated_capacity = tmp / 10; /* property is in mAh */
0725     }
0726 
0727     di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
0728 
0729     sl->family_data = di;
0730 
0731     /* enable sleep mode feature */
0732     ds2760_battery_read_status(di);
0733     status = di->raw[DS2760_STATUS_REG];
0734     if (pmod_enabled)
0735         status |= DS2760_STATUS_PMOD;
0736     else
0737         status &= ~DS2760_STATUS_PMOD;
0738 
0739     ds2760_battery_write_status(di, status);
0740 
0741     /* set rated capacity from module param or device tree */
0742     if (rated_capacity)
0743         ds2760_battery_write_rated_capacity(di, rated_capacity);
0744 
0745     /* set current accumulator if given as parameter.
0746      * this should only be done for bootstrapping the value */
0747     if (current_accum)
0748         ds2760_battery_set_current_accum(di, current_accum);
0749 
0750     di->bat = power_supply_register(dev, &di->bat_desc, &psy_cfg);
0751     if (IS_ERR(di->bat)) {
0752         dev_err(di->dev, "failed to register battery\n");
0753         retval = PTR_ERR(di->bat);
0754         goto batt_failed;
0755     }
0756 
0757     INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
0758     INIT_DELAYED_WORK(&di->set_charged_work,
0759               ds2760_battery_set_charged_work);
0760     di->monitor_wqueue = alloc_ordered_workqueue(name, WQ_MEM_RECLAIM);
0761     if (!di->monitor_wqueue) {
0762         retval = -ESRCH;
0763         goto workqueue_failed;
0764     }
0765     queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
0766 
0767     di->pm_notifier.notifier_call = ds2760_pm_notifier;
0768     register_pm_notifier(&di->pm_notifier);
0769 
0770     goto success;
0771 
0772 workqueue_failed:
0773     power_supply_unregister(di->bat);
0774 batt_failed:
0775 di_alloc_failed:
0776 success:
0777     return retval;
0778 }
0779 
0780 static void w1_ds2760_remove_slave(struct w1_slave *sl)
0781 {
0782     struct ds2760_device_info *di = sl->family_data;
0783 
0784     unregister_pm_notifier(&di->pm_notifier);
0785     cancel_delayed_work_sync(&di->monitor_work);
0786     cancel_delayed_work_sync(&di->set_charged_work);
0787     destroy_workqueue(di->monitor_wqueue);
0788     power_supply_unregister(di->bat);
0789 }
0790 
0791 #ifdef CONFIG_OF
0792 static const struct of_device_id w1_ds2760_of_ids[] = {
0793     { .compatible = "maxim,ds2760" },
0794     {}
0795 };
0796 #endif
0797 
0798 static const struct w1_family_ops w1_ds2760_fops = {
0799     .add_slave  = w1_ds2760_add_slave,
0800     .remove_slave   = w1_ds2760_remove_slave,
0801     .groups     = w1_ds2760_groups,
0802 };
0803 
0804 static struct w1_family w1_ds2760_family = {
0805     .fid        = W1_FAMILY_DS2760,
0806     .fops       = &w1_ds2760_fops,
0807     .of_match_table = of_match_ptr(w1_ds2760_of_ids),
0808 };
0809 module_w1_family(w1_ds2760_family);
0810 
0811 MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
0812           "Matt Reimer <mreimer@vpop.net>, "
0813           "Anton Vorontsov <cbou@mail.ru>");
0814 MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
0815 MODULE_LICENSE("GPL");
0816 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2760));
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