[PATCH v3 4/4] power: Add an axp20x-usb-power driver
Krzysztof Kozlowski
k.kozlowski at samsung.com
Sun Jun 28 03:16:14 PDT 2015
W dniu 28.06.2015 o 05:25, Bruno Prémont pisze:
> On Sat, 27 Jun 2015 14:28:40 Krzysztof Kozlowski wrote:
>> W dniu 26.06.2015 o 19:59, Hans de Goede pisze:
>>> This adds a driver for the usb power_supply bits of the axp20x PMICs.
>>>
>>> I initially started writing my own driver, before coming aware of
>>> Bruno Prémont's excellent earlier RFC with a driver for this.
>>>
>>> My driver was lacking CURRENT_MAX and VOLTAGE_MIN support Bruno's
>>> drvier has, so I've copied the code for those from his driver.
>>>
>>> Note that the AC-power-supply and battery charger bits will need separate
>>> drivers. Each one needs its own devictree child-node so that other
>>> devicetree nodes can reference the right power-supply, and thus each one
>>> will get its own mfd-cell / platform_device and platform-driver.
>>>
>>> Cc: Bruno Prémont <bonbons at linux-vserver.org>
>>> Acked-by: Lee Jones <lee.jones at linaro.org>
>>> Signed-off-by: Bruno Prémont <bonbons at linux-vserver.org>
>>> Signed-off-by: Hans de Goede <hdegoede at redhat.com>
>>> ---
>>> Changes in v2:
>>> -Split out the dt-bindings documentation into a separate patch
>>> -Renamed axp20x_read_16bit to axp20x_read_variable_width
>>> -Use better local variable names inside axp20x_read_variable_width
>>> Changes in v3:
>>> -Add Bruno's S-o-b
>>
>> Hi,
>>
>> Two minor comments below, the driver itself looks good.
>>
>>
>>> ---
>>> drivers/power/Kconfig | 7 ++
>>> drivers/power/Makefile | 1 +
>>> drivers/power/axp20x_usb_power.c | 243 +++++++++++++++++++++++++++++++++++++++
>>> include/linux/mfd/axp20x.h | 24 ++++
>>> 4 files changed, 275 insertions(+)
>>> create mode 100644 drivers/power/axp20x_usb_power.c
>>>
>>> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
>>> index 4091fb0..1fee60c 100644
>>> --- a/drivers/power/Kconfig
>>> +++ b/drivers/power/Kconfig
>>> @@ -439,6 +439,13 @@ config BATTERY_RT5033
>>> The fuelgauge calculates and determines the battery state of charge
>>> according to battery open circuit voltage.
>>>
>>> +config AXP20X_POWER
>>> + tristate "AXP20x power supply driver"
>>> + depends on MFD_AXP20X
>>> + help
>>> + This driver provides support for the power supply features of
>>> + AXP20x PMIC.
>>> +
>>> source "drivers/power/reset/Kconfig"
>>>
>>> endif # POWER_SUPPLY
>>> diff --git a/drivers/power/Makefile b/drivers/power/Makefile
>>> index b7b0181..ae0f27d 100644
>>> --- a/drivers/power/Makefile
>>> +++ b/drivers/power/Makefile
>>> @@ -9,6 +9,7 @@ obj-$(CONFIG_GENERIC_ADC_BATTERY) += generic-adc-battery.o
>>>
>>> obj-$(CONFIG_PDA_POWER) += pda_power.o
>>> obj-$(CONFIG_APM_POWER) += apm_power.o
>>> +obj-$(CONFIG_AXP20X_POWER) += axp20x_usb_power.o
>>> obj-$(CONFIG_MAX8925_POWER) += max8925_power.o
>>> obj-$(CONFIG_WM831X_BACKUP) += wm831x_backup.o
>>> obj-$(CONFIG_WM831X_POWER) += wm831x_power.o
>>> diff --git a/drivers/power/axp20x_usb_power.c b/drivers/power/axp20x_usb_power.c
>>> new file mode 100644
>>> index 0000000..09f388e
>>> --- /dev/null
>>> +++ b/drivers/power/axp20x_usb_power.c
>>> @@ -0,0 +1,243 @@
>>> +/*
>>> + * AXP20x PMIC USB power supply status driver
>>> + *
>>> + * Copyright (C) 2015 Hans de Goede <hdegoede at redhat.com>
>>> + * Copyright (C) 2014 Bruno Prémont <bonbons at linux-vserver.org>
>>> + *
>>> + * 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/device.h>
>>> +#include <linux/init.h>
>>> +#include <linux/interrupt.h>
>>> +#include <linux/kernel.h>
>>> +#include <linux/mfd/axp20x.h>
>>> +#include <linux/module.h>
>>> +#include <linux/of.h>
>>> +#include <linux/platform_device.h>
>>> +#include <linux/power_supply.h>
>>> +#include <linux/regmap.h>
>>> +#include <linux/slab.h>
>>> +
>>> +#define DRVNAME "axp20x-usb-power-supply"
>>> +
>>> +#define AXP20X_PWR_STATUS_VBUS_PRESENT BIT(5)
>>> +#define AXP20X_PWR_STATUS_VBUS_USED BIT(4)
>>> +
>>> +#define AXP20X_USB_STATUS_VBUS_VALID BIT(2)
>>> +
>>> +#define AXP20X_VBUS_VHOLD_uV(b) (4000000 + (((b) >> 3) & 7) * 100000)
>>> +#define AXP20X_VBUS_CLIMIT_MASK 3
>>> +#define AXP20X_VBUC_CLIMIT_900mA 0
>>> +#define AXP20X_VBUC_CLIMIT_500mA 1
>>> +#define AXP20X_VBUC_CLIMIT_100mA 2
>>> +#define AXP20X_VBUC_CLIMIT_NONE 3
>>> +
>>> +#define AXP20X_ADC_EN1_VBUS_CURR BIT(2)
>>> +#define AXP20X_ADC_EN1_VBUS_VOLT BIT(3)
>>> +
>>> +#define AXP20X_VBUS_MON_VBUS_VALID BIT(3)
>>> +
>>> +struct axp20x_usb_power {
>>> + struct regmap *regmap;
>>> + struct power_supply *supply;
>>> +};
>>> +
>>> +static irqreturn_t axp20x_usb_power_irq(int irq, void *devid)
>>> +{
>>> + struct axp20x_usb_power *power = devid;
>>> +
>>> + power_supply_changed(power->supply);
>>> +
>>> + return IRQ_HANDLED;
>>> +}
>>> +
>>> +static int axp20x_usb_power_get_property(struct power_supply *psy,
>>> + enum power_supply_property psp, union power_supply_propval *val)
>>> +{
>>> + struct axp20x_usb_power *power = power_supply_get_drvdata(psy);
>>> + unsigned int input, v;
>>> + int r;
>>
>> Here and in probe function - it is strictly personal but I don't like
>> the 'r' variable. I got used to 'err' or 'ret' which are more
>> descriptive to me. 'r' may look like 'resource' for example.
>
> 'ret' might work but doesn't it imply return value for this function
> instead of return value from a called function?
A little, but in this case it is indeed a return value from called
function. 'err' would fine as well.
>
>>> +
>>> + switch (psp) {
>>> + case POWER_SUPPLY_PROP_VOLTAGE_MIN:
>>> + r = regmap_read(power->regmap, AXP20X_VBUS_IPSOUT_MGMT, &v);
>>> + if (r)
>>> + return r;
>>> +
>>> + val->intval = AXP20X_VBUS_VHOLD_uV(v);
>>> + return 0;
>>> + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
>>> + r = axp20x_read_variable_width(power->regmap,
>>> + AXP20X_VBUS_V_ADC_H, 12);
>>> + if (r < 0)
>>> + return r;
>>> +
>>> + val->intval = r * 1700; /* 1 step = 1.7 mV */
>>> + return 0;
>>> + case POWER_SUPPLY_PROP_CURRENT_MAX:
>>> + r = regmap_read(power->regmap, AXP20X_VBUS_IPSOUT_MGMT, &v);
>>> + if (r)
>>> + return r;
>>> +
>>> + switch (v & AXP20X_VBUS_CLIMIT_MASK) {
>>> + case AXP20X_VBUC_CLIMIT_100mA:
>>> + val->intval = 100000;
>>> + break;
>>> + case AXP20X_VBUC_CLIMIT_500mA:
>>> + val->intval = 500000;
>>> + break;
>>> + case AXP20X_VBUC_CLIMIT_900mA:
>>> + val->intval = 900000;
>>> + break;
>>> + case AXP20X_VBUC_CLIMIT_NONE:
>>> + val->intval = -1;
>>> + break;
>>> + }
>>> + return 0;
>>> + case POWER_SUPPLY_PROP_CURRENT_NOW:
>>> + r = axp20x_read_variable_width(power->regmap,
>>> + AXP20X_VBUS_I_ADC_H, 12);
>>> + if (r < 0)
>>> + return r;
>>> +
>>> + val->intval = r * 375; /* 1 step = 0.375 mA */
>>> + return 0;
>>> + default:
>>> + break;
>>> + }
>>> +
>>> + /* All the properties below need the input-status reg value */
>>> + r = regmap_read(power->regmap, AXP20X_PWR_INPUT_STATUS, &input);
>>> + if (r)
>>> + return r;
>>> +
>>> + switch (psp) {
>>> + case POWER_SUPPLY_PROP_HEALTH:
>>> + if (!(input & AXP20X_PWR_STATUS_VBUS_PRESENT)) {
>>> + val->intval = POWER_SUPPLY_HEALTH_UNKNOWN;
>>> + break;
>>> + }
>>> +
>>> + r = regmap_read(power->regmap, AXP20X_USB_OTG_STATUS, &v);
>>> + if (r)
>>> + return r;
>>> +
>>> + if (!(v & AXP20X_USB_STATUS_VBUS_VALID)) {
>>> + val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
>>> + break;
>>> + }
>>> +
>>> + val->intval = POWER_SUPPLY_HEALTH_GOOD;
>>> + break;
>>> + case POWER_SUPPLY_PROP_PRESENT:
>>> + val->intval = !!(input & AXP20X_PWR_STATUS_VBUS_PRESENT);
>>> + break;
>>> + case POWER_SUPPLY_PROP_ONLINE:
>>> + val->intval = !!(input & AXP20X_PWR_STATUS_VBUS_USED);
>>> + break;
>>> + default:
>>> + return -EINVAL;
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static enum power_supply_property axp20x_usb_power_properties[] = {
>>> + POWER_SUPPLY_PROP_HEALTH,
>>> + POWER_SUPPLY_PROP_PRESENT,
>>> + POWER_SUPPLY_PROP_ONLINE,
>>> + POWER_SUPPLY_PROP_VOLTAGE_MIN,
>>> + POWER_SUPPLY_PROP_VOLTAGE_NOW,
>>> + POWER_SUPPLY_PROP_CURRENT_MAX,
>>> + POWER_SUPPLY_PROP_CURRENT_NOW,
>>> +};
>>> +
>>> +static const struct power_supply_desc axp20x_usb_power_desc = {
>>> + .name = "axp20x-usb",
>>> + .type = POWER_SUPPLY_TYPE_USB,
>>> + .properties = axp20x_usb_power_properties,
>>> + .num_properties = ARRAY_SIZE(axp20x_usb_power_properties),
>>> + .get_property = axp20x_usb_power_get_property,
>>> +};
>>> +
>>> +static int axp20x_usb_power_probe(struct platform_device *pdev)
>>> +{
>>> + struct axp20x_dev *axp20x = dev_get_drvdata(pdev->dev.parent);
>>> + struct power_supply_config psy_cfg = {};
>>> + struct axp20x_usb_power *power;
>>> + static const char * const irq_names[] = { "VBUS_PLUGIN",
>>> + "VBUS_REMOVAL", "VBUS_VALID", "VBUS_NOT_VALID" };
>>> + int i, irq, r;
>>> +
>>> + if (!of_device_is_available(pdev->dev.of_node))
>>> + return -ENODEV;
>>> +
>>> + power = devm_kzalloc(&pdev->dev, sizeof(*power), GFP_KERNEL);
>>> + if (!power)
>>> + return -ENOMEM;
>>> +
>>> + power->regmap = axp20x->regmap;
>>> +
>>> + /* Enable vbus valid checking */
>>> + r = regmap_update_bits(power->regmap, AXP20X_VBUS_MON,
>>> + AXP20X_VBUS_MON_VBUS_VALID, AXP20X_VBUS_MON_VBUS_VALID);
>>> + if (r)
>>> + return r;
>>> +
>>> + /* Enable vbus voltage and current measurement */
>>> + r = regmap_update_bits(power->regmap, AXP20X_ADC_EN1,
>>> + AXP20X_ADC_EN1_VBUS_CURR | AXP20X_ADC_EN1_VBUS_VOLT,
>>> + AXP20X_ADC_EN1_VBUS_CURR | AXP20X_ADC_EN1_VBUS_VOLT);
>>> + if (r)
>>> + return r;
>>> +
>>> + psy_cfg.of_node = pdev->dev.of_node;
>>> + psy_cfg.drv_data = power;
>>> +
>>> + power->supply = devm_power_supply_register(&pdev->dev,
>>> + &axp20x_usb_power_desc, &psy_cfg);
>>> + if (IS_ERR(power->supply))
>>> + return PTR_ERR(power->supply);
>>> +
>>> + /* Request irqs after registering, as irqs may trigger immediately */
>>> + for (i = 0; i < ARRAY_SIZE(irq_names); i++) {
>>> + irq = platform_get_irq_byname(pdev, irq_names[i]);
>>> + if (irq < 0) {
>>> + dev_warn(&pdev->dev, "No IRQ for %s: %d\n",
>>> + irq_names[i], irq);
>>> + continue;
>>> + }
>>> + irq = regmap_irq_get_virq(axp20x->regmap_irqc, irq);
>>> + r = devm_request_any_context_irq(&pdev->dev, irq,
>>> + axp20x_usb_power_irq, 0, DRVNAME, power);
>>> + if (r < 0)
>>> + dev_warn(&pdev->dev, "Error requesting %s IRQ: %d\n",
>>> + irq_names[i], r);
>>> + }
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static const struct of_device_id axp20x_usb_power_match[] = {
>>> + { .compatible = "x-powers,axp202-usb-power-supply" },
>>> + { }
>>> +};
>>> +MODULE_DEVICE_TABLE(of, axp20x_usb_power_match);
>>> +
>>> +static struct platform_driver axp20x_usb_power_driver = {
>>> + .probe = axp20x_usb_power_probe,
>>> + .driver = {
>>> + .name = DRVNAME,
>>> + .of_match_table = axp20x_usb_power_match,
>>> + },
>>> +};
>>> +
>>> +module_platform_driver(axp20x_usb_power_driver);
>>> +
>>> +MODULE_AUTHOR("Hans de Goede <hdegoede at redhat.com>");
>>> +MODULE_DESCRIPTION("AXP20x PMIC USB power supply status driver");
>>> +MODULE_LICENSE("GPL");
>>> diff --git a/include/linux/mfd/axp20x.h b/include/linux/mfd/axp20x.h
>>> index 6d8b39a..8ec996e 100644
>>> --- a/include/linux/mfd/axp20x.h
>>> +++ b/include/linux/mfd/axp20x.h
>>> @@ -11,6 +11,8 @@
>>> #ifndef __LINUX_MFD_AXP20X_H
>>> #define __LINUX_MFD_AXP20X_H
>>>
>>> +#include <linux/regmap.h>
>>> +
>>> enum {
>>> AXP202_ID = 0,
>>> AXP209_ID,
>>> @@ -372,4 +374,26 @@ struct axp288_extcon_pdata {
>>> struct gpio_desc *gpio_mux_cntl;
>>> };
>>>
>>> +/* generic helper function for reading 9-16 bit wide regs */
>>> +static inline int axp20x_read_variable_width(struct regmap *regmap,
>>> + unsigned int reg, unsigned int width)
>>> +{
>>> + unsigned int reg_val, result;
>>> + int err;
>>> +
>>> + err = regmap_read(regmap, reg, ®_val);
>>> + if (err)
>>> + return err;
>>> +
>>> + result = reg_val << (width - 8);
>>> +
>>> + err = regmap_read(regmap, reg + 1, ®_val);
>>> + if (err)
>>> + return err;
>>> +
>>> + result |= reg_val;
>>> +
>>> + return result;
>>> +}
>>> +
>>> #endif /* __LINUX_MFD_AXP20X_H */
>>
>> Is this static inline function used outside of
>> drivers/power/axp20x_usb_power.c? Looks like it isn't, but maybe you
>> have a plan for it? If not, then it shouldn't be in header file.
>
> See comments for first iteration of this patch:
> | | This is only used twice and only in one file.
> | |
> | | Do you know of any other uses of this call that will be upstreamed
> | | shortly?
> |
> | Yes I plan to write drivers for the other 3 power_supply class
> | cells (ac-power, battery-charger, rtc-bat-charger) in the axp209,
> | and most of those need the same helper which I why I put it here.
Thanks for explanation.
Best regards,
Krzysztof
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