Hi, On Thu, Feb 23, 2017 at 06:38:11PM +0100, Enric Balletbo i Serra wrote: > Some of the Toby Churchill devices come with a smart battery and one > AVR XMEGA Microcontroller monitor its state. This patch adds the driver > for this battery monitor.
Sorry for the delay. I'm mostly fine with the driver. You can find a few notes below. > Signed-off-by: Enric Balletbo i Serra <enric.balle...@collabora.com> > --- > drivers/power/supply/Kconfig | 10 + > drivers/power/supply/Makefile | 2 + > drivers/power/supply/xmega16d4_battery.c | 353 > +++++++++++++++++++++++++++++++ > 3 files changed, 365 insertions(+) > create mode 100644 drivers/power/supply/xmega16d4_battery.c > > diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig > index 76806a0..f95f8d5 100644 > --- a/drivers/power/supply/Kconfig > +++ b/drivers/power/supply/Kconfig > @@ -511,4 +511,14 @@ config AXP20X_POWER > This driver provides support for the power supply features of > AXP20x PMIC. > > +config BATTERY_XMEGA16D4 > + tristate "XMEGA16D4 Battery Gauge Driver" > + depends on SPI > + help > + Say Y here to include support for XMEGA16D4 Battery Gauge. The > + driver reports the charge count, and measures the voltage and > + the current. > + > + This adds support for XMEGA16D4 battery. > + > endif # POWER_SUPPLY > diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile > index 36c599d..abae887 100644 > --- a/drivers/power/supply/Makefile > +++ b/drivers/power/supply/Makefile > @@ -72,3 +72,5 @@ obj-$(CONFIG_CHARGER_TPS65090) += tps65090-charger.o > obj-$(CONFIG_CHARGER_TPS65217) += tps65217_charger.o > obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o > obj-$(CONFIG_AXP288_CHARGER) += axp288_charger.o > +obj-$(CONFIG_BATTERY_XMEGA16D4) += xmega16d4_battery.o > + > diff --git a/drivers/power/supply/xmega16d4_battery.c > b/drivers/power/supply/xmega16d4_battery.c > new file mode 100644 > index 0000000..8c6b11a > --- /dev/null > +++ b/drivers/power/supply/xmega16d4_battery.c > @@ -0,0 +1,353 @@ > +/* > + * Battery monitor driver for SL50 Toby Churchill SBS Batteries > + * > + * Copyright (c) 2017, Collabora Ltd. > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/platform_device.h> > +#include <linux/power_supply.h> > +#include <linux/spi/spi.h> > +#include <linux/workqueue.h> > + > +#define SBS_MEMORY_MAP_SIZE 128 > +/* Charging voltage, 2 bytes */ > +#define SBS_CHARGING_VOLTAGE 0x0a > +/* Design voltage, 2 bytes */ > +#define SBS_DESIGN_VOLTAGE 0x0c > +/* Fast charging current, 2 bytes */ > +#define SBS_FAST_CHARGING_CURRENT 0x0e > +/* Max T, Low T, 2 bytes */ > +#define SBS_MAX_LOW_TEMPERATURE 0x10 > +/* Pack capacity, 2 bytes */ > +#define SBS_PACK_CAPACITY 0x12 > +/* Serial number, 2 bytes */ > +#define SBS_SERIAL_NUMBER 0x18 > +/* Manufacturer name, 16 bytes */ > +#define SBS_MANUFACTURER_NAME 0x20 > +/* Model name, 16 bytes */ > +#define SBS_MODEL_NAME 0x30 > +/* Device chemistry, 5 bytes */ > +#define SBS_DEVICE_CHEMISTRY 0x40 > +/* Cycle count, 2 bytes */ > +#define SBS_CYCLE_COUNT 0x50 > +/* Voltage now, 2 bytes */ > +#define SBS_VOLTAGE_NOW 0x70 > +/* Current now, 2 bytes */ > +#define SBS_CURRENT_NOW 0x72 > +/* Battery Status, 2 bytes */ > +#define SBS_BATTERY_STATUS 0x74 > +# define BATTERY_STATUS_CHARGING 0 > +# define BATTERY_STATUS_DISCHARGING BIT(6) > +# define BATTERY_STATUS_FULLY_CHARGED BIT(5) > +/* State of charge in percentage, 1 byte */ > +#define SBS_STATE_OF_CHARGE 0x76 > + > +/* MM SIZE + START(u16) + CHECKSUM(u16) */ > +#define SPI_MSG_LENGTH (SBS_MEMORY_MAP_SIZE + 4) > +#define SPI_MSG_DATA_BP 2 > +/* MSB checksum byte position */ > +#define SPI_MSG_CSUM_BP (2 + SBS_MEMORY_MAP_SIZE) > +#define SPI_MSG_START_TOKEN 0xb00b > + > +struct xmega16d4_battery_data { > + struct spi_device *spi; > + struct power_supply *bat; > + > + struct mutex work_lock; /* protect work data */ > + struct delayed_work bat_work; > + > + u8 map[SBS_MEMORY_MAP_SIZE]; > + > + char model_name[16]; > + char manufacturer_name[16]; > + char serial_number[5]; > + > + int technology; > + int voltage_uV; /* units of uV */ > + int current_uA; /* units of uA */ > + int rated_capacity; /* units of µAh */ > + int cycle_count; > + int rem_capacity; /* percentage */ > + int life_sec; /* units of seconds */ > + int status; /* state of charge */ > +}; > + > +#define MAX_KEYLENGTH 256 > +struct battery_property_map { > + int value; > + char const *key; > +}; > + > +static struct battery_property_map map_technology[] = { > + { POWER_SUPPLY_TECHNOLOGY_NiMH, "NiMH" }, > + { POWER_SUPPLY_TECHNOLOGY_LION, "LION" }, > + { POWER_SUPPLY_TECHNOLOGY_LIPO, "LIPO" }, > + { POWER_SUPPLY_TECHNOLOGY_LiFe, "LiFe" }, > + { POWER_SUPPLY_TECHNOLOGY_NiCd, "NiCd" }, > + { POWER_SUPPLY_TECHNOLOGY_LiMn, "LiMn" }, > + { -1, NULL }, > +}; > + > +static int map_get_value(struct battery_property_map *map, const char *key, > + int def_val) > +{ > + char buf[MAX_KEYLENGTH]; > + int cr; > + > + strncpy(buf, key, MAX_KEYLENGTH); > + buf[MAX_KEYLENGTH - 1] = '\0'; > + > + cr = strnlen(buf, MAX_KEYLENGTH) - 1; > + if (buf[cr] == '\n') > + buf[cr] = '\0'; > + > + while (map->key) { > + if (strncasecmp(map->key, buf, MAX_KEYLENGTH) == 0) > + return map->value; > + map++; > + } > + > + return def_val; > +} > + > +static int xmega16d4_battery_read_status(struct xmega16d4_battery_data *data) > +{ > + int i; > + int csum = 0; > + u8 buf[SBS_MEMORY_MAP_SIZE], technology[5]; > + unsigned int uval; > + int sval; > + struct spi_device *spi = data->spi; > + > + for (i = 0; i < SBS_MEMORY_MAP_SIZE; i++) { > + spi_write(spi, &i, 1); > + spi_read(spi, &buf[i], 1); spi_write_then_read(spi, &i, 1, &buf[i], 1) if (err) complain > + } > + > + print_hex_dump(KERN_DEBUG, ": ", DUMP_PREFIX_OFFSET, 16, 1, > + buf, SBS_MEMORY_MAP_SIZE, false); > + > + /* Calculate the data checksum */ > + for (i = 0; i < SBS_MEMORY_MAP_SIZE - 2; i++) > + csum += buf[i]; > + > + /* Verify the checksum */ > + uval = (buf[SBS_MEMORY_MAP_SIZE - 2] << 8) | > + buf[SBS_MEMORY_MAP_SIZE - 1]; > + if (csum != uval) { > + dev_dbg(&spi->dev, > + "message received with invalid checksum (%d != %d)\n", > + csum, uval); > + return -ENOMSG; dev_dbg? So it happens regularly? > + } > + > + /* Update memory map with the new data */ > + memcpy(data->map, buf, SBS_MEMORY_MAP_SIZE); > + > + strncpy(data->model_name, &data->map[SBS_MODEL_NAME], 16); > + > + strncpy(data->manufacturer_name, &data->map[SBS_MANUFACTURER_NAME], > + 16); > + > + strncpy(technology, &data->map[SBS_DEVICE_CHEMISTRY], 5); > + > + uval = (u16)((data->map[SBS_SERIAL_NUMBER + 1] << 8) | > + data->map[SBS_SERIAL_NUMBER]); > + snprintf(data->serial_number, ARRAY_SIZE(data->serial_number), "%04d", > + uval); > + > + data->technology = map_get_value(map_technology, technology, > + POWER_SUPPLY_TECHNOLOGY_UNKNOWN); > + > + data->voltage_uV = (u16)((data->map[SBS_VOLTAGE_NOW + 1] << 8) | > + data->map[SBS_VOLTAGE_NOW]); > + data->voltage_uV *= 1000; /* convert from mV to uV */ > + > + sval = (s16)((data->map[SBS_CURRENT_NOW + 1] << 8) | > + data->map[SBS_CURRENT_NOW]); > + data->current_uA = sval; > + data->current_uA *= 1000; /* convert from mA to uA */ > + > + data->rated_capacity = (u16)((data->map[SBS_PACK_CAPACITY + 1] << 8) | > + data->map[SBS_PACK_CAPACITY]); > + data->rated_capacity *= 1000; /* convert from mAh to uAh */ > + > + uval = (u16)((data->map[SBS_BATTERY_STATUS + 1] << 8) | > + data->map[SBS_BATTERY_STATUS]); > + if (uval == BATTERY_STATUS_CHARGING) > + data->status = POWER_SUPPLY_STATUS_CHARGING; > + else if (uval == BATTERY_STATUS_DISCHARGING) > + data->status = POWER_SUPPLY_STATUS_DISCHARGING; > + else if (uval == BATTERY_STATUS_FULLY_CHARGED) > + data->status = POWER_SUPPLY_STATUS_FULL; > + else > + data->status = POWER_SUPPLY_STATUS_UNKNOWN; > + > + data->cycle_count = (u16)((data->map[SBS_CYCLE_COUNT + 1] << 8) | > + data->map[SBS_CYCLE_COUNT]); > + > + data->rem_capacity = data->map[SBS_STATE_OF_CHARGE]; > + > + uval = (data->rem_capacity * (data->rated_capacity / 1000)) / 100; > + if (data->current_uA) > + data->life_sec = (3600l * uval) / (data->current_uA / 1000); looks like the driver would benefit from regmap. > + return 0; > +} > + > +static void xmega16d4_battery_work(struct work_struct *work) > +{ > + struct xmega16d4_battery_data *data = container_of(work, > + struct xmega16d4_battery_data, bat_work.work); > + > + /* Update values */ > + mutex_lock(&data->work_lock); > + xmega16d4_battery_read_status(data); > + mutex_unlock(&data->work_lock); > + > + schedule_delayed_work(&data->bat_work, HZ * 60); > +} > + > +static int xmega16d4_battery_get_property(struct power_supply *psy, > + enum power_supply_property psp, > + union power_supply_propval *val) > +{ > + struct xmega16d4_battery_data *data = power_supply_get_drvdata(psy); > + > + switch (psp) { > + case POWER_SUPPLY_PROP_STATUS: > + val->intval = data->status; > + break; > + case POWER_SUPPLY_PROP_VOLTAGE_NOW: > + val->intval = data->voltage_uV; > + break; > + case POWER_SUPPLY_PROP_CURRENT_NOW: > + val->intval = data->current_uA; > + break; > + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN: > + val->intval = data->rated_capacity; > + break; > + case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW: > + val->intval = data->life_sec; > + break; > + case POWER_SUPPLY_PROP_CAPACITY: > + val->intval = data->rem_capacity; > + break; > + case POWER_SUPPLY_PROP_TECHNOLOGY: > + val->intval = data->technology; > + break; > + case POWER_SUPPLY_PROP_MODEL_NAME: > + val->strval = data->model_name; > + break; > + case POWER_SUPPLY_PROP_MANUFACTURER: > + val->strval = data->manufacturer_name; > + break; > + case POWER_SUPPLY_PROP_SERIAL_NUMBER: > + val->strval = data->serial_number; > + break; > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > +static enum power_supply_property xmega16d4_battery_props[] = { > + POWER_SUPPLY_PROP_STATUS, > + POWER_SUPPLY_PROP_VOLTAGE_NOW, > + POWER_SUPPLY_PROP_CURRENT_NOW, > + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN, > + POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW, > + POWER_SUPPLY_PROP_CAPACITY, > + POWER_SUPPLY_PROP_TECHNOLOGY, > + /* Properties of type `const char *' */ > + POWER_SUPPLY_PROP_MODEL_NAME, > + POWER_SUPPLY_PROP_MANUFACTURER, > + POWER_SUPPLY_PROP_SERIAL_NUMBER, > +}; > + > +static const struct power_supply_desc xmega16d4_battery_desc = { > + .name = "battery-monitor", > + .type = POWER_SUPPLY_TYPE_BATTERY, > + .properties = xmega16d4_battery_props, > + .num_properties = ARRAY_SIZE(xmega16d4_battery_props), > + .get_property = xmega16d4_battery_get_property, > +}; > + > +static int xmega16d4_battery_probe(struct spi_device *spi) > +{ > + struct xmega16d4_battery_data *data; > + struct power_supply_config psy_cfg = {}; > + > + data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->spi = spi; > + psy_cfg.of_node = spi->dev.of_node; > + psy_cfg.drv_data = data; > + > + mutex_init(&data->work_lock); > + > + INIT_DELAYED_WORK(&data->bat_work, xmega16d4_battery_work); > + > + spi_set_drvdata(spi, data); > + > + /* Get initial status */ > + if (xmega16d4_battery_read_status(data)) > + return -ENODEV; > + > + data->bat = devm_power_supply_register(&spi->dev, > + &xmega16d4_battery_desc, > + &psy_cfg); > + if (IS_ERR(data->bat)) > + return PTR_ERR(data->bat); > + > + schedule_delayed_work(&data->bat_work, 0); > + > + return 0; > +} > + > +static int xmega16d4_battery_remove(struct spi_device *spi) > +{ > + struct xmega16d4_battery_data *data = spi_get_drvdata(spi); > + > + cancel_delayed_work_sync(&data->bat_work); > + > + return 0; > +} > + > +static const struct of_device_id xmega16d4_battery_of_match[] = { > + { .compatible = "tcl,xmega16d4-battery", }, > + { /* sentinel */ }, > +}; > + > +static struct spi_driver xmega16d4_battery_driver = { > + .driver = { > + .name = "xmega16d4-battery", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(xmega16d4_battery_of_match), Either put xmega16d4_battery_of_match inside of #ifdef CONFIG_OF or drop of_match_ptr. Otherwise there will be an unused warning for the CONFIG_OF=n case. > + }, > + .probe = xmega16d4_battery_probe, > + .remove = xmega16d4_battery_remove, > +}; > +module_spi_driver(xmega16d4_battery_driver); > + > +MODULE_ALIAS("spi:xmega16d4-battery"); > + > +MODULE_LICENSE("GPL v2"); > +MODULE_AUTHOR("Enric Balletbo Serra <enric.balle...@collabora.com>"); > +MODULE_DESCRIPTION("xmega16d4 battery monitor driver"); Otherwise the driver looks fine. I'm a bit worried about the name, though. xmega16d4 is just a microcontroller. This driver is more about its firmware. I think something like "toby-churchill-battery-monitor" would be better. -- Sebastian
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