Thread (12 messages) 12 messages, 3 authors, 2015-06-24

Re: [PATCH 2/2] power_supply: Add support for TI BQ25890 charger chip

From: Krzysztof Kozlowski <hidden>
Date: 2015-05-19 08:40:39
Also in: linux-pm, lkml

2015-05-15 23:06 GMT+09:00 Laurentiu Palcu [off-list ref]:
More details about the chip can be found here:
http://www.ti.com/product/bq25890

Signed-off-by: Laurentiu Palcu <redacted>
---
 drivers/power/Kconfig           |   7 +
 drivers/power/Makefile          |   1 +
 drivers/power/bq25890_charger.c | 998 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 1006 insertions(+)
 create mode 100644 drivers/power/bq25890_charger.c
Hi,

Some comments (nothing serious) inline.

(...)
+
+static int bq25890_field_write(struct bq25890_device *bq,
+                              enum bq25890_fields field_id, u8 val)
+{
+       return regmap_field_write(bq->rmap_fields[field_id], val);
+}
+
+static u8 bq25890_find_idx(u32 value, enum bq25890_table_ids id)
+{
+       u8 idx;
+
+       if (id >= TBL_TREG) {
+               const u32 *tbl = bq25890_tables[id].lt.tbl;
+               u32 tbl_size = bq25890_tables[id].lt.size;
+
+               for (idx = 1; idx < tbl_size && tbl[idx] <= value; idx++)
+                       ;
+       } else {
+               const struct bq25890_range *rtbl = &bq25890_tables[id].rt;
+               u8 rtbl_size;
+
+               rtbl_size = (rtbl->max - rtbl->min) / rtbl->step + 1;
+
+               for (idx = 1;
+                    idx < rtbl_size && idx * rtbl->step + rtbl->min <= value;
Could you add parentheses around part of this expression? It is non
obvious to find the comparison statements.
+                    idx++)
+                       ;
+       }
+
+       return idx - 1;
+}
+
+static u32 bq25890_find_val(u8 idx, enum bq25890_table_ids id)
+{
+       const struct bq25890_range *rtbl;
+
+       /* lookup table? */
+       if (id >= TBL_TREG)
+               return bq25890_tables[id].lt.tbl[idx];
+
+       /* range table */
+       rtbl = &bq25890_tables[id].rt;
+
+       return(rtbl->min + idx * rtbl->step);
A nit: space between return and parenthesis would be nice.
+}
+
+enum bq25890_status {
+       STATUS_NOT_CHARGING,
+       STATUS_PRE_CHARGING,
+       STATUS_FAST_CHARGING,
+       STATUS_TERMINATION_DONE,
+};
+
+enum bq25890_chrg_fault {
+       CHRG_FAULT_NORMAL,
+       CHRG_FAULT_INPUT,
+       CHRG_FAULT_THERMAL_SHUTDOWN,
+       CHRG_FAULT_TIMER_EXPIRED,
+};
+
+static int bq25890_power_supply_get_property(struct power_supply *psy,
+                                            enum power_supply_property psp,
+                                            union power_supply_propval *val)
+{
+       int ret;
+       struct bq25890_device *bq = power_supply_get_drvdata(psy);
+       struct bq25890_state state;
+
+       mutex_lock(&bq->lock);
+       state = bq->state;
+       mutex_unlock(&bq->lock);
+
+       switch (psp) {
+       case POWER_SUPPLY_PROP_STATUS:
+               if (!state.online)
+                       val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+               else if (state.chrg_status == STATUS_NOT_CHARGING)
+                       val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+               else if (state.chrg_status == STATUS_PRE_CHARGING ||
+                        state.chrg_status == STATUS_FAST_CHARGING)
+                       val->intval = POWER_SUPPLY_STATUS_CHARGING;
+               else if (state.chrg_status == STATUS_TERMINATION_DONE)
+                       val->intval = POWER_SUPPLY_STATUS_FULL;
+               else
+                       val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+
+               break;
+
+       case POWER_SUPPLY_PROP_MANUFACTURER:
+               val->strval = BQ25890_MANUFACTURER;
+               break;
+
+       case POWER_SUPPLY_PROP_ONLINE:
+               val->intval = state.online;
+               break;
+
+       case POWER_SUPPLY_PROP_HEALTH:
+               if (!state.chrg_fault && !state.bat_fault && !state.boost_fault)
+                       val->intval = POWER_SUPPLY_HEALTH_GOOD;
+               else if (state.bat_fault)
+                       val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
+               else if (state.chrg_fault == CHRG_FAULT_TIMER_EXPIRED)
+                       val->intval = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
+               else if (state.chrg_fault == CHRG_FAULT_THERMAL_SHUTDOWN)
+                       val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
+               else
+                       val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
+               break;
+
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+               ret = bq25890_field_read(bq, F_ICHGR); /* read measured value */
+               if (ret < 0)
+                       return ret;
+
+               /* converted_val = ADC_val * 50mA (table 10.3.19) */
+               val->intval = ret * 50000;
+               break;
+
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX:
+               val->intval = bq25890_tables[TBL_ICHG].rt.max;
+               break;
+
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE:
+               if (!state.online) {
+                       val->intval = 0;
+                       break;
+               }
+
+               ret = bq25890_field_read(bq, F_BATV); /* read measured value */
+               if (ret < 0)
+                       return ret;
+
+               /* converted_val = 2.304V + ADC_val * 20mV (table 10.3.15) */
+               val->intval = 2304000 + ret * 20000;
+               break;
+
+       case POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX:
+               val->intval = bq25890_tables[TBL_VREG].rt.max;
+               break;
+
+       case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
+               val->intval = bq25890_find_val(bq->init_data.iterm, TBL_ITERM);
+               break;
+
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int bq25890_get_chip_state(struct bq25890_device *bq,
+                                 struct bq25890_state *state)
+{
+       int i, ret;
+
+       struct {
+               enum bq25890_fields id;
+               u8 *data;
+       } state_fields[] = {
+               {F_CHG_STAT,    &state->chrg_status},
+               {F_PG_STAT,     &state->online},
+               {F_VSYS_STAT,   &state->vsys_status},
+               {F_BOOST_FAULT, &state->boost_fault},
+               {F_BAT_FAULT,   &state->bat_fault},
+               {F_CHG_FAULT,   &state->chrg_fault}
+       };
+
+       for (i = 0; i < ARRAY_SIZE(state_fields); i++) {
+               ret = bq25890_field_read(bq, state_fields[i].id);
+               if (ret < 0)
+                       return ret;
+
+               *state_fields[i].data = ret;
+       }
+
+       dev_dbg(bq->dev, "S:CHG/PG/VSYS=%d/%d/%d, F:CHG/BOOST/BAT=%d/%d/%d\n",
+               state->chrg_status, state->online, state->vsys_status,
+               state->chrg_fault, state->boost_fault, state->bat_fault);
+
+       return 0;
+}
+
+static bool bq25890_state_changed(struct bq25890_device *bq,
+                                 struct bq25890_state *new_state)
+{
+       struct bq25890_state old_state;
+
+       mutex_lock(&bq->lock);
+       old_state = bq->state;
+       mutex_unlock(&bq->lock);
+
+       return (old_state.chrg_status != new_state->chrg_status ||
+               old_state.chrg_fault != new_state->chrg_fault   ||
+               old_state.online != new_state->online           ||
+               old_state.bat_fault != new_state->bat_fault     ||
+               old_state.boost_fault != new_state->boost_fault ||
+               old_state.vsys_status != new_state->vsys_status);
+}
+
+static void bq25890_handle_state_change(struct bq25890_device *bq,
+                                       struct bq25890_state *new_state)
+{
+       int ret;
+       struct bq25890_state old_state;
+
+       mutex_lock(&bq->lock);
+       old_state = bq->state;
+       mutex_unlock(&bq->lock);
+
+       if (!new_state->online) {                            /* power removed */
+               /* disable ADC */
+               ret = bq25890_field_write(bq, F_CONV_START, 0);
+               if (ret < 0)
+                       goto error;
+       } else if (!old_state.online) {                     /* power inserted */
+               /* enable ADC, to have control of charge current/voltage */
+               ret = bq25890_field_write(bq, F_CONV_START, 1);
+               if (ret < 0)
+                       goto error;
+       }
+
+       return;
+
+error:
+       dev_err(bq->dev, "%s: Error communicating with the chip.\n", __func__);
The __func__ is not needed here, there is only one kind of such message.
+}
+
+static irqreturn_t bq25890_irq_handler_thread(int irq, void *private)
+{
+       struct bq25890_device *bq = private;
+       int ret;
+       struct bq25890_state state;
+
+       ret = bq25890_get_chip_state(bq, &state);
+       if (ret < 0)
+               goto handled;
+
+       if (!bq25890_state_changed(bq, &state))
+               goto handled;
+
+       bq25890_handle_state_change(bq, &state);
+
+       mutex_lock(&bq->lock);
+       bq->state = state;
+       mutex_unlock(&bq->lock);
+
+       power_supply_changed(bq->charger);
+
+handled:
+       return IRQ_HANDLED;
+}
+
+static int bq25890_chip_reset(struct bq25890_device *bq)
+{
+       int ret;
+
+       ret = bq25890_field_write(bq, F_REG_RST, 1);
+       if (ret < 0)
+               return ret;
+
+       do {
+               ret = bq25890_field_read(bq, F_REG_RST);
+               if (ret < 0)
+                       return ret;
+
+               usleep_range(5, 10);
+       } while (ret == 1);
Is it possible to loop here indefinetely?
+
+       return 0;
+}
+
+static int bq25890_hw_init(struct bq25890_device *bq)
+{
+       int ret;
+       int i;
+       struct bq25890_state state;
+
+       const struct {
+               enum bq25890_fields id;
+               u32 value;
+       } init_data[] = {
+               {F_ICHG,         bq->init_data.ichg},
+               {F_VREG,         bq->init_data.vreg},
+               {F_ITERM,        bq->init_data.iterm},
+               {F_IPRECHG,      bq->init_data.iprechg},
+               {F_SYSVMIN,      bq->init_data.sysvmin},
+               {F_BOOSTV,       bq->init_data.boostv},
+               {F_BOOSTI,       bq->init_data.boosti},
+               {F_BOOSTF,       bq->init_data.boostf},
+               {F_EN_ILIM,      bq->init_data.ilim_en},
+               {F_TREG,         bq->init_data.treg}
+       };
+
+       ret = bq25890_chip_reset(bq);
+       if (ret < 0)
+               return ret;
+
+       /* disable watchdog */
+       ret = bq25890_field_write(bq, F_WD, 0);
+       if (ret < 0)
+               return ret;
+
+       /* initialize currents/voltages and other parameters */
+       for (i = 0; i < ARRAY_SIZE(init_data); i++) {
+               ret = bq25890_field_write(bq, init_data[i].id,
+                                         init_data[i].value);
+               if (ret < 0)
+                       return ret;
+       }
+
+       /* Configure ADC for continuous conversions. This does not enable it. */
+       ret = bq25890_field_write(bq, F_CONV_RATE, 1);
+       if (ret < 0)
+               return ret;
+
+       ret = bq25890_get_chip_state(bq, &state);
+       if (ret < 0)
+               return ret;
+
+       mutex_lock(&bq->lock);
+       bq->state = state;
+       mutex_unlock(&bq->lock);
+
+       return 0;
+}
+
+static enum power_supply_property bq25890_power_supply_props[] = {
+       POWER_SUPPLY_PROP_MANUFACTURER,
+       POWER_SUPPLY_PROP_STATUS,
+       POWER_SUPPLY_PROP_ONLINE,
+       POWER_SUPPLY_PROP_HEALTH,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE,
+       POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
+       POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
+};
+
+static char *bq25890_charger_supplied_to[] = {
+       "main-battery",
+};
+
+static const struct power_supply_desc bq25890_power_supply_desc = {
+       .name = "bq25890-charger",
+       .type = POWER_SUPPLY_TYPE_USB,
+       .properties = bq25890_power_supply_props,
+       .num_properties = ARRAY_SIZE(bq25890_power_supply_props),
+       .get_property = bq25890_power_supply_get_property,
+};
+
+static int bq25890_power_supply_init(struct bq25890_device *bq)
+{
+       struct power_supply_config psy_cfg = { .drv_data = bq, };
+
+       psy_cfg.supplied_to = bq25890_charger_supplied_to;
+       psy_cfg.num_supplicants = ARRAY_SIZE(bq25890_charger_supplied_to);
+
+       bq->charger = power_supply_register(bq->dev, &bq25890_power_supply_desc,
+                                           &psy_cfg);
+       if (IS_ERR(bq->charger))
+               return PTR_ERR(bq->charger);
+
+       return 0;
return PTR_ERR_OR_ZERO
+}
+
+static void bq25890_usb_work(struct work_struct *data)
+{
+       int ret;
+       struct bq25890_device *bq =
+                       container_of(data, struct bq25890_device, usb_work);
+
+       switch (bq->usb_event) {
+       case USB_EVENT_ID:
+               /* Enable boost mode */
+               ret = bq25890_field_write(bq, F_OTG_CFG, 1);
+               if (ret < 0)
+                       goto error;
+               break;
+
+       case USB_EVENT_NONE:
+               /* Disable boost mode */
+               ret = bq25890_field_write(bq, F_OTG_CFG, 0);
+               if (ret < 0)
+                       goto error;
+
+               power_supply_changed(bq->charger);
+               break;
+       }
+
+       return;
+
+error:
+       dev_err(bq->dev, "%s - Error switching to boost/charger mode.\n",
+               __func__);
Again the __func__. It shouldn't be here.
+}
+
+static int bq25890_usb_notifier(struct notifier_block *nb, unsigned long val,
+                               void *priv)
+{
+       struct bq25890_device *bq =
+                       container_of(nb, struct bq25890_device, usb_nb);
+
+       bq->usb_event = val;
+       schedule_work(&bq->usb_work);
If this shouldn't be executed on exactly this CPU then usage of
system_power_efficient_wq is encouraged.
+
+       return NOTIFY_OK;
+}
+
+static int bq25890_irq_probe(struct bq25890_device *bq)
+{
+       int ret;
+       struct gpio_desc *irq;
+
+       irq = devm_gpiod_get_index(bq->dev, BQ25890_IRQ_PIN, 0);
+       if (IS_ERR(irq)) {
+               dev_err(bq->dev, "could not probe irq pin\n");
+               return PTR_ERR(irq);
+       }
+
+       ret = gpiod_direction_input(irq);
+       if (ret < 0)
+               return ret;
+
+       return gpiod_to_irq(irq);
+}
+
+static int bq25890_fw_read_u32_props(struct bq25890_device *bq)
+{
+       int ret;
+       u32 property;
+       int i;
+       struct bq25890_init_data *init = &bq->init_data;
+       struct {
+               char *name;
+               bool optional;
+               enum bq25890_table_ids tbl_id;
+               u8 *conv_data; /* holds converted value from given property */
+       } props[] = {
+               /* required properties */
+               {"ti,charge-current", false, TBL_ICHG, &init->ichg},
+               {"ti,battery-regulation-voltage", false, TBL_VREG, &init->vreg},
+               {"ti,termination-current", false, TBL_ITERM, &init->iterm},
+               {"ti,precharge-current", false, TBL_ITERM, &init->iprechg},
+               {"ti,minimum-sys-voltage", false, TBL_SYSVMIN, &init->sysvmin},
+               {"ti,boost-voltage", false, TBL_BOOSTV, &init->boostv},
+               {"ti,boost-max-current", false, TBL_BOOSTI, &init->boosti},
+
+               /* optional properties */
+               {"ti,thermal-regulation-threshold", true, TBL_TREG, &init->treg}
+       };
+
+       /* initialize data for optional properties */
+       init->treg = 3; /* 120 degrees Celsius */
+
+       for (i = 0; i < ARRAY_SIZE(props); i++) {
+               ret = device_property_read_u32(bq->dev, props[i].name,
+                                              &property);
+               if (ret < 0) {
+                       if (props[i].optional)
+                               continue;
+
+                       return ret;
+               }
+
+               *props[i].conv_data = bq25890_find_idx(property,
+                                                      props[i].tbl_id);
+       }
+
+       return 0;
+}
+
+static int bq25890_fw_probe(struct bq25890_device *bq)
+{
+       int ret;
+       struct bq25890_init_data *init = &bq->init_data;
+
+       ret = bq25890_fw_read_u32_props(bq);
+       if (ret < 0)
+               return ret;
+
+       init->ilim_en = device_property_read_bool(bq->dev, "ti,use-ilim-pin");
+       init->boostf = device_property_read_bool(bq->dev, "ti,boost-low-freq");
+
+       return 0;
+}
+
+static int bq25890_probe(struct i2c_client *client,
+                        const struct i2c_device_id *id)
+{
+       struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+       struct device *dev = &client->dev;
+       struct bq25890_device *bq;
+       int ret;
+       int i;
+
+       if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
+               dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
+               return -ENODEV;
+       }
+
+       bq = devm_kzalloc(dev, sizeof(*bq), GFP_KERNEL);
+       if (!bq)
+               return -ENOMEM;
+
+       bq->client = client;
+       bq->dev = dev;
+
+       mutex_init(&bq->lock);
+
+       bq->rmap = devm_regmap_init_i2c(client, &bq25890_regmap_config);
+       if (IS_ERR(bq->rmap)) {
+               dev_err(dev, "failed to allocate register map\n");
+               return PTR_ERR(bq->rmap);
+       }
+
+       for (i = 0; i < ARRAY_SIZE(bq25890_reg_fields); i++) {
+               const struct reg_field *reg_fields = bq25890_reg_fields;
+
+               bq->rmap_fields[i] = devm_regmap_field_alloc(dev, bq->rmap,
+                                                            reg_fields[i]);
+               if (IS_ERR(bq->rmap_fields[i])) {
+                       dev_err(dev, "cannot allocate regmap field\n");
+                       return PTR_ERR(bq->rmap_fields[i]);
+               }
+       }
+
+       i2c_set_clientdata(client, bq);
+
+       bq->chip_id = bq25890_field_read(bq, F_PN);
+       if (bq->chip_id < 0) {
+               dev_err(dev, "Cannot read chip ID.\n");
+               return ret;
+       }
+
+       if (bq->chip_id != BQ25890_ID) {
+               dev_err(dev, "Chip with ID=%d, not supported!\n", bq->chip_id);
+               return -ENODEV;
+       }
+
+       if (!dev->platform_data) {
+               ret = bq25890_fw_probe(bq);
+               if (ret < 0) {
+                       dev_err(dev, "Cannot read device properties.\n");
+                       return ret;
+               }
+       } else {
+               return -ENODEV;
+       }
+
+       ret = bq25890_hw_init(bq);
+       if (ret < 0) {
+               dev_err(dev, "Cannot initialize the chip.\n");
+               return ret;
+       }
+
+       if (client->irq <= 0)
+               client->irq = bq25890_irq_probe(bq);
+
+       if (client->irq < 0) {
+               dev_err(dev, "no irq resource found\n");
A nit: stick to one convention - capitilize first letter of error message.
+               return client->irq;
+       }
+
+       /* OTG reporting */
+       bq->usb_phy = devm_usb_get_phy(dev, USB_PHY_TYPE_USB2);
+       if (!IS_ERR_OR_NULL(bq->usb_phy)) {
+               INIT_WORK(&bq->usb_work, bq25890_usb_work);
+               bq->usb_nb.notifier_call = bq25890_usb_notifier;
+               usb_register_notifier(bq->usb_phy, &bq->usb_nb);
+       }
+
+       ret = devm_request_threaded_irq(dev, client->irq, NULL,
+                                       bq25890_irq_handler_thread,
+                                       IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+                                       BQ25890_IRQ_PIN, bq);
+       if (ret)
+               goto irq_fail;
+
+       ret = bq25890_power_supply_init(bq);
+       if (ret < 0) {
+               dev_err(dev, "Failed to register power supply\n");
+               goto irq_fail;
+       }
+
+       return 0;
+
+irq_fail:
+       if (!IS_ERR_OR_NULL(bq->usb_phy))
+               usb_unregister_notifier(bq->usb_phy, &bq->usb_nb);
+
+       return ret;
+}
+
+static int bq25890_remove(struct i2c_client *client)
+{
+       struct bq25890_device *bq = i2c_get_clientdata(client);
+
+       if (!IS_ERR_OR_NULL(bq->usb_phy))
+               usb_unregister_notifier(bq->usb_phy, &bq->usb_nb);
+
+       power_supply_unregister(bq->charger);
I would prefer cleaning in reversed order of probe, so first would be
power_supply_unregister(). I think this is expected in usual case.
Often when I encounter such code I wonder - is this non-standard order
of cleanup is important?
+
+       /* reset all registers to default values */
+       bq25890_chip_reset(bq);
+
+       return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int bq25890_suspend(struct device *dev)
+{
+       struct bq25890_device *bq = dev_get_drvdata(dev);
+
+       /*
+        * If charger is removed, while in suspend, make sure ADC is diabled
+        * since it consumes slightly more power.
+        */
+       return bq25890_field_write(bq, F_CONV_START, 0);
+}
+
+static int bq25890_resume(struct device *dev)
+{
+       int ret;
+       struct bq25890_state state;
+       struct bq25890_device *bq = dev_get_drvdata(dev);
+
+       ret = bq25890_get_chip_state(bq, &state);
+       if (ret < 0)
+               return ret;
+
+       mutex_lock(&bq->lock);
+       bq->state = state;
+       mutex_unlock(&bq->lock);
+
+       /* Re-enable ADC only if charger is plugged in. */
+       if (bq->state.online) {
Shouldn't you be here accessing local variable state?

Best regards,
Krzysztof
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