Re: [PATCH 2/2] power: supply: Add Spreadtrum SC2731 charger support

From: Baolin Wang
Date: Wed Aug 29 2018 - 23:09:03 EST


Hi Krzysztof,

On 29 August 2018 at 22:36, Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
> I'll try one more time... but without HTML from Gmail. Previous mail
> bounced from lists.
>
> On Tue, 28 Aug 2018 at 11:04, Baolin Wang <baolin.wang@xxxxxxxxxx> wrote:
>>
>> This patch adds the SC2731 PMIC switch charger support.
>>
>> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxx>
>> ---
>> drivers/power/supply/Kconfig | 7 +
>> drivers/power/supply/Makefile | 1 +
>> drivers/power/supply/sc2731_charger.c | 451 +++++++++++++++++++++++++++++++++
>> 3 files changed, 459 insertions(+)
>> create mode 100644 drivers/power/supply/sc2731_charger.c
>>
>> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
>> index ff6dab0..f27cf07 100644
>> --- a/drivers/power/supply/Kconfig
>> +++ b/drivers/power/supply/Kconfig
>> @@ -645,4 +645,11 @@ config CHARGER_CROS_USBPD
>> what is connected to USB PD ports from the EC and converts
>> that into power_supply properties.
>>
>> +config CHARGER_SC2731
>> + tristate "Spreadtrum SC2731 charger driver"
>> + depends on MFD_SC27XX_PMIC || COMPILE_TEST
>> + help
>> + Say Y here to enable support for battery charging with SC2731
>> + PMIC chips.
>> +
>> endif # POWER_SUPPLY
>> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
>> index a26b402..767105b 100644
>> --- a/drivers/power/supply/Makefile
>> +++ b/drivers/power/supply/Makefile
>> @@ -85,3 +85,4 @@ 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_CHARGER_CROS_USBPD) += cros_usbpd-charger.o
>> +obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o
>> diff --git a/drivers/power/supply/sc2731_charger.c b/drivers/power/supply/sc2731_charger.c
>> new file mode 100644
>> index 0000000..49ae16a
>> --- /dev/null
>> +++ b/drivers/power/supply/sc2731_charger.c
>> @@ -0,0 +1,451 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (C) 2018 Spreadtrum Communications Inc.
>> +
>> +#include <linux/err.h>
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/power_supply.h>
>> +#include <linux/slab.h>
>
> slab.h includes looks not needed.

Right. will remove it.

>
>> +#include <linux/usb/phy.h>
>> +#include <linux/regmap.h>
>> +#include <linux/extcon.h>
>
> Looks not used.

Will remove it.

>
>> +#include <linux/notifier.h>
>> +#include <linux/of.h>
>> +
>> +/* PMIC global registers definition */
>> +#define SC2731_CHARGE_STATUS 0xedc
>> +#define SC2731_CHARGE_FULL BIT(4)
>> +#define SC2731_MODULE_EN1 0xc0c
>> +#define SC2731_CHARGE_EN BIT(5)
>> +
>> +/* SC2731 switch charger registers definition */
>> +#define SC2731_CHG_CFG0 0x0
>> +#define SC2731_CHG_CFG1 0x4
>> +#define SC2731_CHG_CFG2 0x8
>> +#define SC2731_CHG_CFG3 0xc
>> +#define SC2731_CHG_CFG4 0x10
>> +#define SC2731_CHG_CFG5 0x28
>> +
>> +/* SC2731_CHG_CFG0 register definition */
>> +#define SC2731_PRECHG_RNG_SHIFT 11
>> +#define SC2731_PRECHG_RNG_MASK GENMASK(12, 11)
>> +
>> +#define SC2731_TERMINATION_VOL_MASK GENMASK(2, 1)
>> +#define SC2731_TERMINATION_VOL_SHIFT 1
>> +#define SC2731_TERMINATION_VOL_CAL_MASK GENMASK(8, 3)
>> +#define SC2731_TERMINATION_VOL_CAL_SHIFT 3
>> +#define SC2731_TERMINATION_CUR_MASK GENMASK(2, 0)
>> +
>> +#define SC2731_CC_EN BIT(13)
>> +#define SC2731_CHARGER_PD BIT(0)
>> +
>> +/* SC2731_CHG_CFG1 register definition */
>> +#define SC2731_CUR_MASK GENMASK(5, 0)
>> +
>> +/* SC2731_CHG_CFG5 register definition */
>> +#define SC2731_CUR_LIMIT_SHIFT 8
>> +#define SC2731_CUR_LIMIT_MASK GENMASK(9, 8)
>> +
>> +#define SC2731_CURRENT_LIMIT_100 100
>> +#define SC2731_CURRENT_LIMIT_500 500
>> +#define SC2731_CURRENT_LIMIT_900 900
>> +#define SC2731_CURRENT_LIMIT_2000 2000
>> +
>> +#define SC2731_CURRENT_PRECHG 450
>> +#define SC2731_CURRENT_STEP 50
>
> What units are used for all these currents?

Sorry for confusing, and will add comments to explain these macros or
add one postfix âMAâ.

>
>> +
>> +struct sc2731_charger_info {
>> + struct device *dev;
>> + struct regmap *regmap;
>> + struct usb_phy *usb_phy;
>> + struct notifier_block usb_notify;
>> + struct power_supply *psy_usb;
>> + bool charging;
>> + u32 base;
>> +};
>> +
>> +static void sc2731_charger_stop_charge(struct sc2731_charger_info *info)
>> +{
>> + regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> + SC2731_CC_EN, 0);
>> +
>> + regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> + SC2731_CHARGER_PD, SC2731_CHARGER_PD);
>> +}
>> +
>> +static int sc2731_charger_start_charge(struct sc2731_charger_info *info)
>> +{
>> + int ret;
>> +
>> + /* Enable charger constant current mode */
>> + ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> + SC2731_CC_EN, SC2731_CC_EN);
>> + if (ret)
>> + return ret;
>> +
>> + /* Start charging */
>> + return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> + SC2731_CHARGER_PD, 0);
>> +}
>> +
>> +static int sc2731_charger_set_current_limit(struct sc2731_charger_info *info,
>> + u32 limit)
>> +{
>> + u32 val;
>> +
>> + if (limit <= SC2731_CURRENT_LIMIT_100)
>> + val = 0;
>> + else if (limit <= SC2731_CURRENT_LIMIT_500)
>> + val = 3;
>> + else if (limit <= SC2731_CURRENT_LIMIT_900)
>> + val = 2;
>> + else
>> + val = 1;
>> +
>> + return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG5,
>> + SC2731_CUR_LIMIT_MASK,
>> + val << SC2731_CUR_LIMIT_SHIFT);
>> +}
>> +
>> +static int sc2731_charger_set_current(struct sc2731_charger_info *info, u32 cur)
>> +{
>> + u32 val;
>> + int ret;
>> +
>> + if (cur > SC2731_CURRENT_LIMIT_2000)
>> + cur = SC2731_CURRENT_LIMIT_2000;
>> + else if (cur < SC2731_CURRENT_PRECHG)
>> + cur = SC2731_CURRENT_PRECHG;
>> +
>> + /* Calculte the step value, each step is 50 mA */
>
> s/Calculte/Calculate/

Sorry for typos.

>
>> + val = (cur - SC2731_CURRENT_PRECHG) / SC2731_CURRENT_STEP;
>> +
>> + /* Set pre-charge current as 450 mA */
>> + ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> + SC2731_PRECHG_RNG_MASK,
>> + 0x3 << SC2731_PRECHG_RNG_SHIFT);
>> + if (ret)
>> + return ret;
>> +
>> + return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG1,
>> + SC2731_CUR_MASK, val);
>> +}
>> +
>> +static int sc2731_charger_get_status(struct sc2731_charger_info *info)
>> +{
>> + u32 val;
>> + int ret;
>> +
>> + ret = regmap_read(info->regmap, SC2731_CHARGE_STATUS, &val);
>> + if (ret)
>> + return ret;
>> +
>> + if (val & SC2731_CHARGE_FULL)
>> + return POWER_SUPPLY_STATUS_FULL;
>> +
>> + return POWER_SUPPLY_STATUS_CHARGING;
>> +}
>> +
>> +static int sc2731_charger_get_current(struct sc2731_charger_info *info,
>> + u32 *cur)
>> +{
>> + int ret;
>> + u32 val;
>> +
>> + ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG1, &val);
>> + if (ret)
>> + return ret;
>> +
>> + val &= SC2731_CUR_MASK;
>> + *cur = val * SC2731_CURRENT_STEP + SC2731_CURRENT_PRECHG;
>
> One empty line please.

OK.

>
>> + return 0;
>> +}
>> +
>> +static int sc2731_charger_get_current_limit(struct sc2731_charger_info *info,
>> + u32 *cur)
>> +{
>> + int ret;
>> + u32 val;
>> +
>> + ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG5, &val);
>> + if (ret)
>> + return ret;
>> +
>> + val = (val & SC2731_CUR_LIMIT_MASK) >> SC2731_CUR_LIMIT_SHIFT;
>> +
>> + switch (val) {
>> + case 0:
>> + *cur = SC2731_CURRENT_LIMIT_100;
>> + break;
>> +
>> + case 1:
>> + *cur = SC2731_CURRENT_LIMIT_2000;
>> + break;
>> +
>> + case 2:
>> + *cur = SC2731_CURRENT_LIMIT_900;
>> + break;
>> +
>> + case 3:
>> + *cur = SC2731_CURRENT_LIMIT_500;
>> + break;
>> +
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int
>> +sc2731_charger_usb_set_property(struct power_supply *psy,
>> + enum power_supply_property psp,
>> + const union power_supply_propval *val)
>> +{
>> + struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
>> + int ret;
>> +
>> + switch (psp) {
>> + case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>> + ret = sc2731_charger_set_current(info, val->intval);
>> + if (ret < 0)
>> + dev_warn(info->dev, "set charge current failed\n");
>> + break;
>> + case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
>> + ret = sc2731_charger_set_current_limit(info, val->intval);
>> + if (ret < 0)
>> + dev_warn(info->dev, "set input current limit failed\n");
>> + break;
>> + default:
>> + ret = -EINVAL;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static int sc2731_charger_usb_get_property(struct power_supply *psy,
>> + enum power_supply_property psp,
>> + union power_supply_propval *val)
>> +{
>> + struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
>> + u32 cur;
>> + int ret;
>> +
>> + switch (psp) {
>> + case POWER_SUPPLY_PROP_STATUS:
>> + if (info->charging)
>> + val->intval = sc2731_charger_get_status(info);
>> + else
>> + val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>> + if (!info->charging) {
>> + val->intval = 0;
>> + break;
>> + }
>> +
>> + ret = sc2731_charger_get_current(info, &cur);
>> + if (ret)
>> + return ret;
>> +
>> + val->intval = cur;
>> + break;
>> +
>> + case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
>> + if (!info->charging) {
>> + val->intval = 0;
>> + break;
>> + }
>> +
>> + ret = sc2731_charger_get_current_limit(info, &cur);
>> + if (ret)
>> + return ret;
>> +
>> + val->intval = cur;
>> + break;
>> +
>> + default:
>> + return -EINVAL;
>> + }
>> +
>> + return 0;
>> +}
>> +
>> +static int sc2731_charger_property_is_writeable(struct power_supply *psy,
>> + enum power_supply_property psp)
>> +{
>> + int ret;
>> +
>> + switch (psp) {
>> + case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>> + case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
>> + ret = 1;
>> + break;
>> + default:
>> + ret = 0;
>> + }
>> +
>> + return ret;
>> +}
>> +
>> +static enum power_supply_property sc2731_usb_props[] = {
>> + POWER_SUPPLY_PROP_STATUS,
>> + POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
>> + POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
>> +};
>> +
>> +static const struct power_supply_desc sc2731_charger_desc = {
>> + .name = "sc2731_charger",
>> + .type = POWER_SUPPLY_TYPE_USB,
>> + .properties = sc2731_usb_props,
>> + .num_properties = ARRAY_SIZE(sc2731_usb_props),
>> + .get_property = sc2731_charger_usb_get_property,
>> + .set_property = sc2731_charger_usb_set_property,
>> + .property_is_writeable = sc2731_charger_property_is_writeable,
>> +};
>> +
>> +static int sc2731_charger_usb_change(struct notifier_block *nb,
>> + unsigned long limit, void *data)
>> +{
>> + struct sc2731_charger_info *info =
>> + container_of(nb, struct sc2731_charger_info, usb_notify);
>> + int ret;
>> +
>> + /* set current limitation and start to charge */
>> + if (limit > 0) {
>> + ret = sc2731_charger_set_current_limit(info, limit);
>> + if (ret)
>> + return ret;
>> +
>> + ret = sc2731_charger_set_current(info, limit);
>> + if (ret)
>> + return ret;
>> +
>> + ret = sc2731_charger_start_charge(info);
>> + if (ret)
>> + return ret;
>> +
>> + info->charging = true;
>> + return 0;
>> + }
>> +
>> + /* Stop charging */
>> + sc2731_charger_stop_charge(info);
>> + info->charging = false;
>
> Here and in other places (get_property) you depend on information from
> USB phy. But maybe your device already provides information whether it
> is charging or not. It should be more accurate.

Make sense. Will think about this issue.

>
>> +
>> + return 0;
>> +}
>> +
>> +static int sc2731_charger_hw_init(struct sc2731_charger_info *info)
>> +{
>> + int ret;
>> +
>> + /* Enable charger module */
>> + ret = regmap_update_bits(info->regmap, SC2731_MODULE_EN1,
>> + SC2731_CHARGE_EN, SC2731_CHARGE_EN);
>> + if (ret)
>> + return ret;
>> +
>> + /* Set default charge termination current to 120 mA */
>> + ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG2,
>> + SC2731_TERMINATION_CUR_MASK, 0x2);
>
> Looks like DeviceTree property.

OK.

>
>> + if (ret)
>> + goto error;
>> +
>> + /* Set default charge termination voltage to 4.35V */
>
> Looks like DeviceTree property.

OK. Thanks for your comments.


--
Baolin Wang
Best Regards