Hi Hans,
On Sat, Mar 25, 2017 at 02:55:50PM +0100, Hans de Goede wrote:
> Add a driver for the Cherry Trail Whiskey Cove PMIC Fuel Gauge.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
The driver looks fine to me. I think it would be nice to use
regmap for accessing the device, though. Its capability to
dump registers in debugfs is often useful, especially for
reverse engineered drivers.
Also I assume, that you made sure the reported values are correctly
scaled to uV/uA and not mV/mA? Just asking, since people regularly
get this wrong and your scaling looks suspiciously small.
-- Sebastian
> ---
> Changes in v2:
> -There was no v2, it is skipped to the version in sync with the rest of
> the patch-set
> Changes in v3:
> -Change into a stand-alone power_supply battery driver instead of being a
> provider of extra properties for another battery driver
> -Rename Kconfig symbol from CHT_WC_FUEL_GAUGE to BATTERY_INTEL_CHT_WC
> ---
> drivers/power/supply/Kconfig | 9 +
> drivers/power/supply/Makefile | 1 +
> drivers/power/supply/cht_wc_fuel_gauge.c | 319 +++++++++++++++++++++++++++++++
> 3 files changed, 329 insertions(+)
> create mode 100644 drivers/power/supply/cht_wc_fuel_gauge.c
>
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index fd93110..350d86a 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -538,4 +538,13 @@ config AXP20X_POWER
> This driver provides support for the power supply features of
> AXP20x PMIC.
>
> +config BATTERY_INTEL_CHT_WC
> + tristate "Intel Cherry Trail Whiskey Cove PMIC Fuel Gauge"
> + depends on INTEL_SOC_PMIC_CHTWC
> + help
> + This adds support for the battery fuel gauge found in the Intel
> + Cherry Trail Whiskey Cove PMIC. This driver allows monitoring
> + of the charge level of the battery on Intel Cherry Trail systems
> + with a Whiskey Cove PMIC.
> +
> endif # POWER_SUPPLY
> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> index 3789a2c..46dca5c 100644
> --- a/drivers/power/supply/Makefile
> +++ b/drivers/power/supply/Makefile
> @@ -74,3 +74,4 @@ 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_INTEL_CHT_WC) += cht_wc_fuel_gauge.o
> diff --git a/drivers/power/supply/cht_wc_fuel_gauge.c b/drivers/power/supply/cht_wc_fuel_gauge.c
> new file mode 100644
> index 0000000..0db83ad
> --- /dev/null
> +++ b/drivers/power/supply/cht_wc_fuel_gauge.c
> @@ -0,0 +1,319 @@
> +/*
> + * Intel Cherry Trail Whiskey Cove Fuel Gauge driver
> + * Copyright (C) 2017 Hans de Goede <hdegoede@xxxxxxxxxx>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that 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.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/delay.h>
> +#include <linux/extcon.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/mfd/intel_soc_pmic.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/power_supply.h>
> +#include <linux/slab.h>
> +#include <linux/workqueue.h>
> +
> +#define FG_CHARGE_NOW 0x05
> +#define FG_VOLTAGE_NOW 0x09
> +#define FG_CURRENT_NOW 0x0a
> +#define FG_CURRENT_AVG 0x0b
> +#define FG_CHARGE_FULL 0x10
> +#define FG_CHARGE_DESIGN 0x18
> +#define FG_VOLTAGE_AVG 0x19
> +#define FG_VOLTAGE_OCV 0x1b /* Only updated during charging */
> +
> +#define PMIC_CHGRSTATUS 0x1a
> +#define PMIC_CHGRSTATUS_NOT_CHARGING BIT(0)
> +
> +#define CHT_WC_FG_PTYPE 4
> +
> +static const unsigned int charger_cable_ids[] = {
> + EXTCON_CHG_USB_SDP, EXTCON_CHG_USB_CDP,
> + EXTCON_CHG_USB_DCP, EXTCON_CHG_USB_ACA
> +};
> +
> +struct cht_wc_fg_data {
> + struct device *dev;
> + /*
> + * The ACPI _CRS table contains info for 4 clients, 1 for the charger-
> + * manager part of the pmic and 3 for the actual fuel-gauge (which has
> + * 3 i2c addresses) note we use only 1 fg address/client.
> + */
> + struct i2c_client *pmic_client;
> + struct i2c_client *fg_client;
> + struct extcon_dev *extcon;
> + struct power_supply *battery;
> + struct work_struct changed_work;
> + struct notifier_block extcon_nb;
> +};
> +
> +static int cht_wc_fg_read(struct cht_wc_fg_data *fg, u8 reg,
> + union power_supply_propval *val, int scale,
> + int sign_extend)
> +{
> + int ret;
> +
> + ret = i2c_smbus_read_word_data(fg->fg_client, reg);
> + if (ret < 0)
> + return ret;
> +
> + if (sign_extend)
> + ret = sign_extend32(ret, 15);
> +
> + val->intval = ret * scale;
> +
> + return 0;
> +}
> +
> +static int cht_wc_fg_get_status(struct cht_wc_fg_data *fg,
> + union power_supply_propval *val)
> +{
> + int i, ret;
> + bool vbus_present = false;
> +
> + for (i = 0; i < ARRAY_SIZE(charger_cable_ids); i++) {
> + if (extcon_get_state(fg->extcon, charger_cable_ids[i]) > 0) {
> + vbus_present = true;
> + break;
> + }
> + }
> +
> + if (!vbus_present) {
> + val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
> + return 0;
> + }
> +
> + ret = i2c_smbus_read_byte_data(fg->pmic_client, PMIC_CHGRSTATUS);
> + if (ret < 0)
> + return ret;
> +
> + /* Not charging while we have Vbus means the battery is full */
> + if (ret & PMIC_CHGRSTATUS_NOT_CHARGING)
> + val->intval = POWER_SUPPLY_STATUS_FULL;
> + else
> + val->intval = POWER_SUPPLY_STATUS_CHARGING;
> +
> + return 0;
> +}
> +
> +static int cht_wc_fg_get_property(struct power_supply *psy,
> + enum power_supply_property prop, union power_supply_propval *val)
> +{
> + struct cht_wc_fg_data *fg = power_supply_get_drvdata(psy);
> + int ret = 0;
> +
> + switch (prop) {
> + case POWER_SUPPLY_PROP_STATUS:
> + ret = cht_wc_fg_get_status(fg, val);
> + break;
> + case POWER_SUPPLY_PROP_PRESENT:
> + val->intval = 1;
> + break;
> + case POWER_SUPPLY_PROP_TECHNOLOGY:
> + val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> + ret = cht_wc_fg_read(fg, FG_VOLTAGE_NOW, val, 75, 0);
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_AVG:
> + ret = cht_wc_fg_read(fg, FG_VOLTAGE_AVG, val, 75, 0);
> + break;
> + case POWER_SUPPLY_PROP_VOLTAGE_OCV:
> + ret = cht_wc_fg_read(fg, FG_VOLTAGE_OCV, val, 75, 0);
> + break;
> + case POWER_SUPPLY_PROP_CURRENT_NOW:
> + ret = cht_wc_fg_read(fg, FG_CURRENT_NOW, val, 150, 1);
> + break;
> + case POWER_SUPPLY_PROP_CURRENT_AVG:
> + ret = cht_wc_fg_read(fg, FG_CURRENT_AVG, val, 150, 1);
> + break;
> + case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
> + ret = cht_wc_fg_read(fg, FG_CHARGE_DESIGN, val, 500, 0);
> + break;
> + case POWER_SUPPLY_PROP_CHARGE_FULL:
> + ret = cht_wc_fg_read(fg, FG_CHARGE_FULL, val, 500, 0);
> + break;
> + case POWER_SUPPLY_PROP_CHARGE_NOW:
> + ret = cht_wc_fg_read(fg, FG_CHARGE_NOW, val, 500, 0);
> + break;
> + case POWER_SUPPLY_PROP_SCOPE:
> + val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
> + break;
> + default:
> + ret = -ENODATA;
> + }
> +
> + return ret;
> +}
> +
> +static void cht_wc_fg_external_power_changed(struct power_supply *psy)
> +{
> + struct cht_wc_fg_data *fg = power_supply_get_drvdata(psy);
> +
> + schedule_work(&fg->changed_work);
> +}
> +
> +static enum power_supply_property cht_wc_fg_properties[] = {
> + POWER_SUPPLY_PROP_STATUS,
> + POWER_SUPPLY_PROP_PRESENT,
> + POWER_SUPPLY_PROP_TECHNOLOGY,
> + POWER_SUPPLY_PROP_VOLTAGE_NOW,
> + POWER_SUPPLY_PROP_VOLTAGE_AVG,
> + POWER_SUPPLY_PROP_VOLTAGE_OCV,
> + POWER_SUPPLY_PROP_CURRENT_NOW,
> + POWER_SUPPLY_PROP_CURRENT_AVG,
> + POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
> + POWER_SUPPLY_PROP_CHARGE_FULL,
> + POWER_SUPPLY_PROP_CHARGE_NOW,
> + POWER_SUPPLY_PROP_SCOPE,
> +};
> +
> +static const struct power_supply_desc bat_desc = {
> + /* Matches charger.supplied_to for external_power_changed callback */
> + .name = "main-battery",
> + .type = POWER_SUPPLY_TYPE_BATTERY,
> + .properties = cht_wc_fg_properties,
> + .num_properties = ARRAY_SIZE(cht_wc_fg_properties),
> + .get_property = cht_wc_fg_get_property,
> + .external_power_changed = cht_wc_fg_external_power_changed,
> +};
> +
> +static void cht_wc_fg_changed_work(struct work_struct *work)
> +{
> + struct cht_wc_fg_data *fg =
> + container_of(work, struct cht_wc_fg_data, changed_work);
> +
> + /* Wait a bit to allow the fuel-gauge to also detect the new status */
> + msleep(200);
> +
> + power_supply_changed(fg->battery);
> +}
> +
> +static int cht_wc_fg_extcon_event(struct notifier_block *nb,
> + unsigned long event, void *param)
> +{
> + struct cht_wc_fg_data *fg =
> + container_of(nb, struct cht_wc_fg_data, extcon_nb);
> +
> + schedule_work(&fg->changed_work);
> +
> + return NOTIFY_OK;
> +}
> +
> +static int cht_wc_fg_probe(struct i2c_client *client,
> + const struct i2c_device_id *i2c_id)
> +{
> + struct device *dev = &client->dev;
> + struct power_supply_config bat_cfg = {};
> + struct cht_wc_fg_data *fg;
> + acpi_status status;
> + unsigned long long ptyp;
> + int ret;
> +
> + status = acpi_evaluate_integer(ACPI_HANDLE(dev), "PTYP", NULL, &ptyp);
> + if (ACPI_FAILURE(status)) {
> + dev_err(dev, "Failed to get PTYPE\n");
> + return -ENODEV;
> + }
> +
> + /*
> + * The same ACPI HID is used with different PMICs check PTYP to
> + * ensure that we are dealing with a Whiskey Cove PMIC.
> + */
> + if (ptyp != CHT_WC_FG_PTYPE)
> + return -ENODEV;
> +
> + fg = devm_kzalloc(dev, sizeof(*fg), GFP_KERNEL);
> + if (!fg)
> + return -ENOMEM;
> +
> + fg->dev = dev;
> + fg->pmic_client = client;
> + INIT_WORK(&fg->changed_work, cht_wc_fg_changed_work);
> +
> + /*
> + * We use the Whiskey Cove PMIC's pwrsrc detection block to see
> + * if we are charging or not. We could access the pwrsrc regs
> + * ourselves, but that requires re-implementing the extcon code,
> + * so we just use the extcon interface.
> + */
> + fg->extcon = extcon_get_extcon_dev("cht_wcove_pwrsrc");
> + if (!fg->extcon)
> + return -EPROBE_DEFER;
> +
> + /*
> + * The current resource settings table for the fuel gauge contains
> + * multiple i2c devices on 2 different i2c-busses.
> + */
> + fg->fg_client = i2c_acpi_new_device(dev, 1);
> + if (!fg->fg_client)
> + return -EPROBE_DEFER;
> +
> + bat_cfg.drv_data = fg;
> + fg->battery = devm_power_supply_register(dev, &bat_desc, &bat_cfg);
> + if (IS_ERR(fg->battery)) {
> + i2c_unregister_device(fg->fg_client);
> + return PTR_ERR(fg->battery);
> + }
> +
> + fg->extcon_nb.notifier_call = cht_wc_fg_extcon_event;
> + ret = devm_extcon_register_notifier(dev, fg->extcon, -1,
> + &fg->extcon_nb);
> + if (ret) {
> + i2c_unregister_device(fg->fg_client);
> + return ret;
> + }
> +
> + i2c_set_clientdata(client, fg);
> +
> + return 0;
> +}
> +
> +static int cht_wc_fg_remove(struct i2c_client *i2c)
> +{
> + struct cht_wc_fg_data *fg = i2c_get_clientdata(i2c);
> +
> + i2c_unregister_device(fg->fg_client);
> +
> + return 0;
> +}
> +
> +static const struct i2c_device_id cht_wc_fg_i2c_id[] = {
> + { }
> +};
> +MODULE_DEVICE_TABLE(i2c, cht_wc_fg_i2c_id);
> +
> +static const struct acpi_device_id cht_wc_fg_acpi_ids[] = {
> + { "INT33FE", },
> + { }
> +};
> +MODULE_DEVICE_TABLE(acpi, cht_wc_fg_acpi_ids);
> +
> +static struct i2c_driver cht_wc_fg_driver = {
> + .driver = {
> + .name = "CHT Whiskey Cove PMIC Fuel Gauge",
> + .acpi_match_table = ACPI_PTR(cht_wc_fg_acpi_ids),
> + },
> + .probe = cht_wc_fg_probe,
> + .remove = cht_wc_fg_remove,
> + .id_table = cht_wc_fg_i2c_id,
> + .irq_index = 1,
> +};
> +
> +module_i2c_driver(cht_wc_fg_driver);
> +
> +MODULE_DESCRIPTION("Intel CHT Whiskey Cove PMIC Fuel Gauge driver");
> +MODULE_AUTHOR("Hans de Goede <hdegoede@xxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
> --
> 2.9.3
>
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