On Fri, 26 Jun 2015, Adam Thomson wrote: > Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx> > --- > drivers/power/Kconfig | 10 + > drivers/power/Makefile | 1 + > drivers/power/da9150-fg.c | 589 ++++++++++++++++++++++++++++++++++++++++++ > include/linux/mfd/da9150/fg.h | 10 + > 4 files changed, 610 insertions(+) > create mode 100644 drivers/power/da9150-fg.c > > diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig > index 4091fb0..8054f1a 100644 > --- a/drivers/power/Kconfig > +++ b/drivers/power/Kconfig > @@ -204,6 +204,16 @@ config CHARGER_DA9150 > This driver can also be built as a module. If so, the module will be > called da9150-charger. > > +config FG_DA9150 > + tristate "Dialog Semiconductor DA9150 Fuel Gauge support" > + depends on CHARGER_DA9150 > + help > + Say Y here to enable support for the Fuel-Gauge unit of the DA9150 > + Integrated Charger & Fuel-Gauge IC > + > + This driver can also be built as a module. If so, the module will be > + called da9150-fg. > + > config AXP288_FUEL_GAUGE > tristate "X-Powers AXP288 Fuel Gauge" > depends on MFD_AXP20X && IIO > diff --git a/drivers/power/Makefile b/drivers/power/Makefile > index b7b0181..b421b54 100644 > --- a/drivers/power/Makefile > +++ b/drivers/power/Makefile > @@ -33,6 +33,7 @@ obj-$(CONFIG_BATTERY_BQ27x00) += bq27x00_battery.o > obj-$(CONFIG_BATTERY_DA9030) += da9030_battery.o > obj-$(CONFIG_BATTERY_DA9052) += da9052-battery.o > obj-$(CONFIG_CHARGER_DA9150) += da9150-charger.o > +obj-$(CONFIG_FG_DA9150) += da9150-fg.o > obj-$(CONFIG_BATTERY_MAX17040) += max17040_battery.o > obj-$(CONFIG_BATTERY_MAX17042) += max17042_battery.o > obj-$(CONFIG_BATTERY_Z2) += z2_battery.o > diff --git a/drivers/power/da9150-fg.c b/drivers/power/da9150-fg.c > new file mode 100644 > index 0000000..8dee156 > --- /dev/null > +++ b/drivers/power/da9150-fg.c > @@ -0,0 +1,589 @@ > +/* > + * DA9150 Fuel-Gauge Driver > + * > + * Copyright (c) 2015 Dialog Semiconductor > + * > + * Author: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms of the GNU General Public License as published by the > + * Free Software Foundation; either version 2 of the License, or (at your > + * option) any later version. > + */ > + > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/of.h> > +#include <linux/of_platform.h> > +#include <linux/slab.h> > +#include <linux/interrupt.h> > +#include <linux/delay.h> > +#include <linux/power_supply.h> > +#include <linux/list.h> > +#include <asm/div64.h> > +#include <linux/mfd/da9150/core.h> > +#include <linux/mfd/da9150/registers.h> > +#include <linux/mfd/da9150/fg.h> > + > +/* Core2Wire */ > +#define DA9150_QIF_READ (0x0 << 7) > +#define DA9150_QIF_WRITE (0x1 << 7) > +#define DA9150_QIF_CODE_MASK 0x7F > + > +#define DA9150_QIF_BYTE_SIZE 8 > +#define DA9150_QIF_BYTE_MASK 0xFF > +#define DA9150_QIF_SHORT_SIZE 2 > +#define DA9150_QIF_LONG_SIZE 4 > + > +/* QIF Codes */ > +#define DA9150_QIF_UAVG 6 > +#define DA9150_QIF_UAVG_SIZE DA9150_QIF_LONG_SIZE > +#define DA9150_QIF_IAVG 8 > +#define DA9150_QIF_IAVG_SIZE DA9150_QIF_LONG_SIZE > +#define DA9150_QIF_NTCAVG 12 > +#define DA9150_QIF_NTCAVG_SIZE DA9150_QIF_LONG_SIZE > +#define DA9150_QIF_SHUNT_VAL 36 > +#define DA9150_QIF_SHUNT_VAL_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_SD_GAIN 38 > +#define DA9150_QIF_SD_GAIN_SIZE DA9150_QIF_LONG_SIZE > +#define DA9150_QIF_FCC_MAH 40 > +#define DA9150_QIF_FCC_MAH_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_SOC_PCT 43 > +#define DA9150_QIF_SOC_PCT_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_CHARGE_LIMIT 44 > +#define DA9150_QIF_CHARGE_LIMIT_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_DISCHARGE_LIMIT 45 > +#define DA9150_QIF_DISCHARGE_LIMIT_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_FW_MAIN_VER 118 > +#define DA9150_QIF_FW_MAIN_VER_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_E_FG_STATUS 126 > +#define DA9150_QIF_E_FG_STATUS_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_SYNC 127 > +#define DA9150_QIF_SYNC_SIZE DA9150_QIF_SHORT_SIZE > +#define DA9150_QIF_MAX_CODES 128 > + > +/* QIF Sync Timeout */ > +#define DA9150_QIF_SYNC_TIMEOUT 1000 > +#define DA9150_QIF_SYNC_RETRIES 10 > + > +/* QIF E_FG_STATUS */ > +#define DA9150_FG_IRQ_LOW_SOC_MASK (1 << 0) > +#define DA9150_FG_IRQ_HIGH_SOC_MASK (1 << 1) > + > +/* Private data */ > +struct da9150_fg { > + struct da9150 *da9150; > + struct device *dev; > + > + struct mutex io_lock; > + > + struct power_supply *battery; > + struct delayed_work work; > + u32 interval; > + > + da9150_read_temp_t read_bat_temp; > + void *bat_temp_context; > + > + int warn_soc; > + int crit_soc; > + int soc; > +}; > + > +/* Battery Properties */ > +static u32 da9150_fg_read_attr(struct da9150_fg *fg, u8 code, u8 size) > + > +{ > + u8 buf[size]; > + u8 read_addr; > + u32 res = 0; > + int i; > + > + /* Set QIF code (READ mode) */ > + read_addr = (code & DA9150_QIF_CODE_MASK) | DA9150_QIF_READ; > + > + da9150_read_qif(fg->da9150, read_addr, size, buf); > + for (i = 0; i < size; ++i) > + res |= (buf[i] << (i * DA9150_QIF_BYTE_SIZE)); > + > + return res; > +} > + > +static void da9150_fg_write_attr(struct da9150_fg *fg, u8 code, u8 size, > + u32 val) > + > +{ > + u8 buf[size]; > + u8 write_addr; > + int i; > + > + /* Set QIF code (WRITE mode) */ > + write_addr = (code & DA9150_QIF_CODE_MASK) | DA9150_QIF_WRITE; > + > + for (i = 0; i < size; ++i) { > + buf[i] = (val >> (i * DA9150_QIF_BYTE_SIZE)) & > + DA9150_QIF_BYTE_MASK; > + } > + da9150_write_qif(fg->da9150, write_addr, size, buf); > +} > + > +/* Trigger QIF Sync to update QIF readable data */ > +static void da9150_fg_read_sync_start(struct da9150_fg *fg) > +{ > + int i = 0; > + u32 res = 0; > + > + mutex_lock(&fg->io_lock); > + > + /* Check if QIF sync already requested, and write to sync if not */ > + res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC, > + DA9150_QIF_SYNC_SIZE); > + if (res > 0) > + da9150_fg_write_attr(fg, DA9150_QIF_SYNC, > + DA9150_QIF_SYNC_SIZE, 0); > + > + /* Wait for sync to complete */ > + res = 0; > + while ((res == 0) && (i++ < DA9150_QIF_SYNC_RETRIES)) { > + usleep_range(DA9150_QIF_SYNC_TIMEOUT, > + DA9150_QIF_SYNC_TIMEOUT * 2); > + res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC, > + DA9150_QIF_SYNC_SIZE); > + } > + > + /* Check if sync completed */ > + if (res == 0) > + dev_err(fg->dev, "Failed to perform QIF read sync!\n"); > +} > + > +/* > + * Should always be called after QIF sync read has been performed, and all > + * attributes required have been accessed. > + */ > +static inline void da9150_fg_read_sync_end(struct da9150_fg *fg) > +{ > + mutex_unlock(&fg->io_lock); > +} > + > +/* Wait for QIF Sync, write QIF data and wait for ack */ > +static void da9150_fg_write_attr_sync(struct da9150_fg *fg, u8 code, u8 size, > + u32 val) > +{ > + int i = 0; > + u32 res = 0, sync_val; > + > + mutex_lock(&fg->io_lock); > + > + /* Check if QIF sync already requested */ > + res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC, > + DA9150_QIF_SYNC_SIZE); > + > + /* Wait for an existing sync to complete */ > + while ((res == 0) && (i++ < DA9150_QIF_SYNC_RETRIES)) { > + usleep_range(DA9150_QIF_SYNC_TIMEOUT, > + DA9150_QIF_SYNC_TIMEOUT * 2); > + res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC, > + DA9150_QIF_SYNC_SIZE); > + } > + > + if (res == 0) { > + dev_err(fg->dev, "Timeout waiting for existing QIF sync!\n"); > + mutex_unlock(&fg->io_lock); > + return; > + } > + > + /* Write value for QIF code */ > + da9150_fg_write_attr(fg, code, size, val); > + > + /* Wait for write acknowledgment */ > + i = 0; > + sync_val = res; > + while ((res == sync_val) && (i++ < DA9150_QIF_SYNC_RETRIES)) { > + usleep_range(DA9150_QIF_SYNC_TIMEOUT, > + DA9150_QIF_SYNC_TIMEOUT * 2); > + res = da9150_fg_read_attr(fg, DA9150_QIF_SYNC, > + DA9150_QIF_SYNC_SIZE); > + } > + > + mutex_unlock(&fg->io_lock); > + > + /* Check write was actually successful */ > + if (res != (sync_val + 1)) > + dev_err(fg->dev, "Error performing QIF sync write for code %d\n", > + code); > +} > + > +/* Power Supply attributes */ > +static int da9150_fg_capacity(struct da9150_fg *fg, > + union power_supply_propval *val) > +{ > + da9150_fg_read_sync_start(fg); > + val->intval = da9150_fg_read_attr(fg, DA9150_QIF_SOC_PCT, > + DA9150_QIF_SOC_PCT_SIZE); > + da9150_fg_read_sync_end(fg); > + > + if (val->intval > 100) > + val->intval = 100; > + > + return 0; > +} > + > +static int da9150_fg_current_avg(struct da9150_fg *fg, > + union power_supply_propval *val) > +{ > + u32 iavg, sd_gain, shunt_val; > + u64 div, res; > + > + da9150_fg_read_sync_start(fg); > + iavg = da9150_fg_read_attr(fg, DA9150_QIF_IAVG, > + DA9150_QIF_IAVG_SIZE); > + shunt_val = da9150_fg_read_attr(fg, DA9150_QIF_SHUNT_VAL, > + DA9150_QIF_SHUNT_VAL_SIZE); > + sd_gain = da9150_fg_read_attr(fg, DA9150_QIF_SD_GAIN, > + DA9150_QIF_SD_GAIN_SIZE); > + da9150_fg_read_sync_end(fg); > + > + div = (u64) (sd_gain * shunt_val * 65536ULL); > + do_div(div, 1000000); > + res = (u64) (iavg * 1000000ULL); > + do_div(res, div); > + > + val->intval = (int) res; > + > + return 0; > +} > + > +static int da9150_fg_voltage_avg(struct da9150_fg *fg, > + union power_supply_propval *val) > +{ > + u64 res; > + > + da9150_fg_read_sync_start(fg); > + val->intval = da9150_fg_read_attr(fg, DA9150_QIF_UAVG, > + DA9150_QIF_UAVG_SIZE); > + da9150_fg_read_sync_end(fg); > + > + res = (u64) (val->intval * 186ULL); > + do_div(res, 10000); > + val->intval = (int) res; > + > + return 0; > +} > + > +static int da9150_fg_charge_full(struct da9150_fg *fg, > + union power_supply_propval *val) > +{ > + da9150_fg_read_sync_start(fg); > + val->intval = da9150_fg_read_attr(fg, DA9150_QIF_FCC_MAH, > + DA9150_QIF_FCC_MAH_SIZE); > + da9150_fg_read_sync_end(fg); > + > + val->intval = val->intval * 1000; > + > + return 0; > +} > + > +static int da9150_fg_temp(struct da9150_fg *fg, > + union power_supply_propval *val) > +{ > + if (!fg->read_bat_temp) { > + da9150_fg_read_sync_start(fg); > + val->intval = da9150_fg_read_attr(fg, DA9150_QIF_NTCAVG, > + DA9150_QIF_NTCAVG_SIZE); > + da9150_fg_read_sync_end(fg); > + > + val->intval = (val->intval * 10) / 1048576; > + } else { > + val->intval = fg->read_bat_temp(fg->bat_temp_context); > + } > + > + return 0; > +} > + > +static enum power_supply_property da9150_fg_props[] = { > + POWER_SUPPLY_PROP_CAPACITY, > + POWER_SUPPLY_PROP_CURRENT_AVG, > + POWER_SUPPLY_PROP_VOLTAGE_AVG, > + POWER_SUPPLY_PROP_CHARGE_FULL, > + POWER_SUPPLY_PROP_TEMP, > +}; > + > +static int da9150_fg_get_prop(struct power_supply *psy, > + enum power_supply_property psp, > + union power_supply_propval *val) > +{ > + struct da9150_fg *fg = dev_get_drvdata(psy->dev.parent); > + int ret; > + > + switch (psp) { > + case POWER_SUPPLY_PROP_CAPACITY: > + ret = da9150_fg_capacity(fg, val); > + break; > + case POWER_SUPPLY_PROP_CURRENT_AVG: > + ret = da9150_fg_current_avg(fg, val); > + break; > + case POWER_SUPPLY_PROP_VOLTAGE_AVG: > + ret = da9150_fg_voltage_avg(fg, val); > + break; > + case POWER_SUPPLY_PROP_CHARGE_FULL: > + ret = da9150_fg_charge_full(fg, val); > + break; > + case POWER_SUPPLY_PROP_TEMP: > + ret = da9150_fg_temp(fg, val); > + break; > + default: > + ret = -EINVAL; > + break; > + } > + > + return ret; > +} > + > +/* Repeated SOC check */ > +static bool da9150_fg_soc_changed(struct da9150_fg *fg) > +{ > + union power_supply_propval val; > + > + da9150_fg_capacity(fg, &val); > + if (val.intval != fg->soc) { > + fg->soc = val.intval; > + return true; > + } > + > + return false; > +} > + > +static void da9150_fg_work(struct work_struct *work) > +{ > + struct da9150_fg *fg = container_of(work, struct da9150_fg, work.work); > + > + /* Report if SOC has changed */ > + if (da9150_fg_soc_changed(fg)) > + power_supply_changed(fg->battery); > + > + schedule_delayed_work(&fg->work, msecs_to_jiffies(fg->interval)); > +} > + > +/* Register external function to give battery temperature */ > +void da9150_fg_register_temp_cb(struct power_supply *psy, da9150_read_temp_t cb, > + void *cb_context) > +{ > + struct da9150_fg *fg = dev_get_drvdata(psy->dev.parent); > + > + fg->read_bat_temp = cb; > + fg->bat_temp_context = cb_context; > +} > +EXPORT_SYMBOL_GPL(da9150_fg_register_temp_cb); > + > +/* SOC level event configuration */ > +static void da9150_fg_soc_event_config(struct da9150_fg *fg) > +{ > + int soc; > + > + da9150_fg_read_sync_start(fg); > + soc = da9150_fg_read_attr(fg, DA9150_QIF_SOC_PCT, > + DA9150_QIF_SOC_PCT_SIZE); > + da9150_fg_read_sync_end(fg); > + > + if (soc > fg->warn_soc) { > + /* If SOC > warn level, set discharge warn level event */ > + da9150_fg_write_attr_sync(fg, DA9150_QIF_DISCHARGE_LIMIT, > + DA9150_QIF_DISCHARGE_LIMIT_SIZE, > + fg->warn_soc + 1); > + } else if ((soc <= fg->warn_soc) && (soc > fg->crit_soc)) { > + /* > + * If SOC <= warn level, set discharge crit level event, > + * and set charge warn level event. > + */ > + da9150_fg_write_attr_sync(fg, DA9150_QIF_DISCHARGE_LIMIT, > + DA9150_QIF_DISCHARGE_LIMIT_SIZE, > + fg->crit_soc + 1); > + > + da9150_fg_write_attr_sync(fg, DA9150_QIF_CHARGE_LIMIT, > + DA9150_QIF_CHARGE_LIMIT_SIZE, > + fg->warn_soc); > + } else if (soc <= fg->crit_soc) { > + /* If SOC <= crit level, set charge crit level event */ > + da9150_fg_write_attr_sync(fg, DA9150_QIF_CHARGE_LIMIT, > + DA9150_QIF_CHARGE_LIMIT_SIZE, > + fg->crit_soc); > + } > +} > + > +static irqreturn_t da9150_fg_irq(int irq, void *data) > +{ > + struct da9150_fg *fg = data; > + u32 e_fg_status; > + > + /* Read FG IRQ status info */ > + e_fg_status = da9150_fg_read_attr(fg, DA9150_QIF_E_FG_STATUS, > + DA9150_QIF_E_FG_STATUS_SIZE); > + > + /* Handle warning/critical threhold events */ > + if ((DA9150_FG_IRQ_LOW_SOC_MASK | DA9150_FG_IRQ_HIGH_SOC_MASK) & > + e_fg_status) > + da9150_fg_soc_event_config(fg); > + > + /* Clear any FG IRQs */ > + da9150_fg_write_attr(fg, DA9150_QIF_E_FG_STATUS, > + DA9150_QIF_E_FG_STATUS_SIZE, e_fg_status); > + > + return IRQ_HANDLED; > +} > + > +static struct da9150_fg_pdata *da9150_fg_dt_pdata(struct device *dev) > +{ > + struct device_node *fg_node = dev->of_node; > + struct da9150_fg_pdata *pdata; > + > + pdata = devm_kzalloc(dev, sizeof(struct da9150_fg_pdata), GFP_KERNEL); > + if (!pdata) > + return NULL; > + > + of_property_read_u32(fg_node, "dlg,update-interval", > + &pdata->update_interval); > + of_property_read_u8(fg_node, "dlg,warn-soc-level", > + &pdata->warn_soc_lvl); > + of_property_read_u8(fg_node, "dlg,crit-soc-level", > + &pdata->crit_soc_lvl); > + > + return pdata; > +} > + > +static const struct power_supply_desc fg_desc = { > + .name = "da9150-fg", > + .type = POWER_SUPPLY_TYPE_BATTERY, > + .properties = da9150_fg_props, > + .num_properties = ARRAY_SIZE(da9150_fg_props), > + .get_property = da9150_fg_get_prop, > +}; > + > +static int da9150_fg_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct da9150 *da9150 = dev_get_drvdata(dev->parent); > + struct da9150_fg_pdata *fg_pdata = dev_get_platdata(dev); > + struct da9150_fg *fg; > + int ver, irq, ret; > + > + fg = devm_kzalloc(dev, sizeof(*fg), GFP_KERNEL); > + if (fg == NULL) > + return -ENOMEM; > + > + platform_set_drvdata(pdev, fg); > + fg->da9150 = da9150; > + fg->dev = dev; > + > + mutex_init(&fg->io_lock); > + > + /* Enable QIF */ > + da9150_set_bits(da9150, DA9150_CORE2WIRE_CTRL_A, DA9150_FG_QIF_EN_MASK, > + DA9150_FG_QIF_EN_MASK); > + > + fg->battery = power_supply_register(dev, &fg_desc, NULL); > + if (IS_ERR(fg->battery)) { > + ret = PTR_ERR(fg->battery); > + return ret; > + } > + > + ver = da9150_fg_read_attr(fg, DA9150_QIF_FW_MAIN_VER, > + DA9150_QIF_FW_MAIN_VER_SIZE); > + dev_info(dev, "Version: 0x%x\n", ver); > + > + /* Handle DT data if provided */ > + if (dev->of_node) { > + fg_pdata = da9150_fg_dt_pdata(dev); > + dev->platform_data = fg_pdata; > + } > + > + /* Handle any pdata provided */ > + if (fg_pdata) { > + fg->interval = fg_pdata->update_interval; > + > + if (fg_pdata->warn_soc_lvl > 100) > + dev_warn(dev, "Invalid SOC warning level provided, Ignoring"); > + else > + fg->warn_soc = fg_pdata->warn_soc_lvl; > + > + if ((fg_pdata->crit_soc_lvl > 100) || > + (fg_pdata->crit_soc_lvl >= fg_pdata->warn_soc_lvl)) > + dev_warn(dev, "Invalid SOC critical level provided, Ignoring"); > + else > + fg->crit_soc = fg_pdata->crit_soc_lvl; > + > + > + } > + > + /* Configure initial SOC level events */ > + da9150_fg_soc_event_config(fg); > + > + /* > + * If an interval period has been provided then setup repeating > + * work for reporting data updates. > + */ > + if (fg->interval) { > + INIT_DELAYED_WORK(&fg->work, da9150_fg_work); > + schedule_delayed_work(&fg->work, > + msecs_to_jiffies(fg->interval)); > + } > + > + /* Register IRQ */ > + irq = platform_get_irq_byname(pdev, "FG"); > + ret = request_threaded_irq(irq, NULL, da9150_fg_irq, IRQF_ONESHOT, "FG", > + fg); > + if (ret) > + goto irq_fail; > + > + return ret; > + > +irq_fail: > + cancel_delayed_work(&fg->work); > + power_supply_unregister(fg->battery); > + > + return ret; > +} > + > +static int da9150_fg_remove(struct platform_device *pdev) > +{ > + struct da9150_fg *fg = platform_get_drvdata(pdev); > + int irq; > + > + irq = platform_get_irq_byname(pdev, "FG"); > + free_irq(irq, fg); > + > + if (fg->interval) > + cancel_delayed_work(&fg->work); > + > + power_supply_unregister(fg->battery); > + > + return 0; > +} > + > +static int da9150_fg_resume(struct platform_device *pdev) > +{ > + struct da9150_fg *fg = platform_get_drvdata(pdev); > + > + /* > + * Trigger SOC check to happen now so as to indicate any value change > + * since last check before suspend. > + */ > + if (fg->interval) > + flush_delayed_work(&fg->work); > + > + return 0; > +} > + > +static struct platform_driver da9150_fg_driver = { > + .driver = { > + .name = "da9150-fuelgauge", > + }, > + .probe = da9150_fg_probe, > + .remove = da9150_fg_remove, > + .resume = da9150_fg_resume, > +}; > + > +module_platform_driver(da9150_fg_driver); > + > +MODULE_DESCRIPTION("Fuel-Gauge Driver for DA9150"); > +MODULE_AUTHOR("Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx>"); > +MODULE_LICENSE("GPL"); > diff --git a/include/linux/mfd/da9150/fg.h b/include/linux/mfd/da9150/fg.h > index 0ff52ab..2cff203 100644 > --- a/include/linux/mfd/da9150/fg.h > +++ b/include/linux/mfd/da9150/fg.h > @@ -26,4 +26,14 @@ struct da9150_fg_pdata { > u8 crit_soc_lvl; /* % value */ > }; > > +/* > + * Function template to provide battery temperature. Should provide > + * 0.1 degrees C resolution return values. > + */ > +typedef int (*da9150_read_temp_t)(void *context); > + > +/* Register temp callback function */ > +void da9150_fg_register_temp_cb(struct power_supply *psy, da9150_read_temp_t cb, > + void *cb_context); > + > #endif /* __DA9150_FG_H */ I still don't get why you think pointers are better than just calling the function directly. Can the *fn() ever point to different functions? -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html