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[23.128.96.18]) by mx.google.com with ESMTP id o3si2903594eja.202.2020.05.27.18.58.35; Wed, 27 May 2020 18:58:58 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726914AbgE1B4U (ORCPT + 99 others); Wed, 27 May 2020 21:56:20 -0400 Received: from mail-io1-f68.google.com ([209.85.166.68]:42501 "EHLO mail-io1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725849AbgE1B4U (ORCPT ); Wed, 27 May 2020 21:56:20 -0400 Received: by mail-io1-f68.google.com with SMTP id d5so18796261ios.9; Wed, 27 May 2020 18:56:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=vfVnDrSq58NuSUbJV6oCnXeF8igJvtjoYDR7txMoucI=; b=VcwpsdGUWCz0rmZ+d1lj9WfZ3sS7d8TymolJGbG8h/nthXmYXLnVkeZLItIwdStv4g 4IxfkqEjuX2Zd8z/XyzS+0kirz3qtfiSVMSexpikMhyCo6tij8vFdXoxuIo2YnKlcZ8m 9A3f4+sHKEpv2MTETtE0q3B4NpuR+xIyJBHrsFTFIPNbeXgZyRMGHJUW2UGLWm1+iNSa Xm8CVdxaw0W86XgcJWA+1/5nWl65mt+fatZuPJIiDQvDqjYT5JyPWxsd1I/m1QzgTdJ4 aPG72i0xfz0oNrCulhyyQGWf6xgqzgQtj/rxmv+Ku8vWxBu2qhFBZcVihkR/9TX+JsFk gvSw== X-Gm-Message-State: AOAM531wux+aZYaB1qCMZ+dvsaFV0VvQV0uTfuVubdbT9f1o5OKYHp7L 4JtxIpAeSRQzTi3N9e8EFg== X-Received: by 2002:a05:6638:a50:: with SMTP id 16mr443081jap.71.1590630977260; Wed, 27 May 2020 18:56:17 -0700 (PDT) Received: from xps15 ([64.188.179.252]) by smtp.gmail.com with ESMTPSA id r68sm2438424ilb.37.2020.05.27.18.56.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 May 2020 18:56:16 -0700 (PDT) Received: (nullmailer pid 3201004 invoked by uid 1000); Thu, 28 May 2020 01:56:15 -0000 Date: Wed, 27 May 2020 19:56:15 -0600 From: Rob Herring To: Sebastian Reichel Cc: Sebastian Reichel , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@collabora.com Subject: Re: [PATCHv1 1/2] power: supply: gpio-charger: add charge-current-limit feature Message-ID: <20200528015615.GA3176121@bogus> References: <20200513115601.360642-1-sebastian.reichel@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200513115601.360642-1-sebastian.reichel@collabora.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, May 13, 2020 at 01:56:00PM +0200, Sebastian Reichel wrote: > Add new charge-current-limit feature to gpio-charger. This also > makes the online status GPIO optional, since hardware might only > expose the charge-current-limit feature and there is no good reason > to have it mandatory now that different GPIOs are supported. > > Signed-off-by: Sebastian Reichel > --- > .../bindings/power/supply/gpio-charger.txt | 11 +- > drivers/power/supply/gpio-charger.c | 176 ++++++++++++++++-- > 2 files changed, 174 insertions(+), 13 deletions(-) > > diff --git a/Documentation/devicetree/bindings/power/supply/gpio-charger.txt b/Documentation/devicetree/bindings/power/supply/gpio-charger.txt > index 0fb33b2c62a6..dbfd29029f69 100644 > --- a/Documentation/devicetree/bindings/power/supply/gpio-charger.txt > +++ b/Documentation/devicetree/bindings/power/supply/gpio-charger.txt > @@ -2,8 +2,6 @@ gpio-charger > > Required properties : > - compatible : "gpio-charger" > - - gpios : GPIO indicating the charger presence. > - See GPIO binding in bindings/gpio/gpio.txt . > - charger-type : power supply type, one of > unknown > battery > @@ -15,7 +13,13 @@ Required properties : > usb-aca (USB accessory charger adapter) > > Optional properties: > + - gpios : GPIO indicating the charger presence. > + See GPIO binding in bindings/gpio/gpio.txt . > - charge-status-gpios: GPIO indicating whether a battery is charging. > + - charge-current-limit-gpios: Output GPIOs specifiers for limiting the charge current > + - charge-current-limit-mapping: List of touples with current in uA and a GPIO bitmap (in this order). > + The GPIOs are encoded in the same order as specified in charge-current-limit-gpios. TBC, index 0 GPIO is bit 0? > + The touples must be provided in descending order of the current limit. tuples Wrap at 80 columns. > > Example: > > @@ -24,6 +28,9 @@ Example: > charger-type = "usb-sdp"; > gpios = <&gpd 28 GPIO_ACTIVE_LOW>; > charge-status-gpios = <&gpc 27 GPIO_ACTIVE_LOW>; > + > + charge-current-limit-gpios = <&gpioA 11 GPIO_ACTIVE_HIGH>, <&gpioA 12 GPIO_ACTIVE_HIGH>; > + charge-current-limit-mapping = <2500000 0x00>, <700000 0x01>, <0 0x02>; > }; > > battery { > diff --git a/drivers/power/supply/gpio-charger.c b/drivers/power/supply/gpio-charger.c > index 1b959c7f8b0e..4a5eac7cc36c 100644 > --- a/drivers/power/supply/gpio-charger.c > +++ b/drivers/power/supply/gpio-charger.c > @@ -18,7 +18,13 @@ > > #include > > +struct gpio_mapping { > + u32 limit_ua; > + u32 gpiodata; > +} __packed; > + > struct gpio_charger { > + struct device *dev; > unsigned int irq; > unsigned int charge_status_irq; > bool wakeup_enabled; > @@ -27,6 +33,11 @@ struct gpio_charger { > struct power_supply_desc charger_desc; > struct gpio_desc *gpiod; > struct gpio_desc *charge_status; > + > + struct gpio_descs *current_limit_gpios; > + struct gpio_mapping *current_limit_map; > + u32 current_limit_map_size; > + u32 charge_current_limit; > }; > > static irqreturn_t gpio_charger_irq(int irq, void *devid) > @@ -43,6 +54,35 @@ static inline struct gpio_charger *psy_to_gpio_charger(struct power_supply *psy) > return power_supply_get_drvdata(psy); > } > > +static int set_charge_current_limit(struct gpio_charger *gpio_charger, int val) > +{ > + struct gpio_mapping mapping; > + int ndescs = gpio_charger->current_limit_gpios->ndescs; > + struct gpio_desc **gpios = gpio_charger->current_limit_gpios->desc; > + int i; > + > + if (!gpio_charger->current_limit_map_size) > + return -EINVAL; > + > + for (i = 0; i < gpio_charger->current_limit_map_size; i++) { > + if (gpio_charger->current_limit_map[i].limit_ua <= val) > + break; > + } > + mapping = gpio_charger->current_limit_map[i]; > + > + for (i = 0; i < ndescs; i++) { > + bool val = (mapping.gpiodata >> i) & 1; > + gpiod_set_value_cansleep(gpios[ndescs-i-1], val); > + } > + > + gpio_charger->charge_current_limit = mapping.limit_ua; > + > + dev_dbg(gpio_charger->dev, "set charge current limit to %d (requested: %d)\n", > + gpio_charger->charge_current_limit, val); > + > + return 0; > +} > + > static int gpio_charger_get_property(struct power_supply *psy, > enum power_supply_property psp, union power_supply_propval *val) > { > @@ -58,6 +98,9 @@ static int gpio_charger_get_property(struct power_supply *psy, > else > val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; > break; > + case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX: > + val->intval = gpio_charger->charge_current_limit; > + break; > default: > return -EINVAL; > } > @@ -65,6 +108,34 @@ static int gpio_charger_get_property(struct power_supply *psy, > return 0; > } > > +static int gpio_charger_set_property(struct power_supply *psy, > + enum power_supply_property psp, const union power_supply_propval *val) > +{ > + struct gpio_charger *gpio_charger = psy_to_gpio_charger(psy); > + > + switch (psp) { > + case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX: > + return set_charge_current_limit(gpio_charger, val->intval); > + default: > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int gpio_charger_property_is_writeable(struct power_supply *psy, > + enum power_supply_property psp) > +{ > + switch (psp) { > + case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX: > + return 1; > + default: > + break; > + } > + > + return 0; > +} > + > static enum power_supply_type gpio_charger_get_type(struct device *dev) > { > const char *chargetype; > @@ -112,9 +183,70 @@ static int gpio_charger_get_irq(struct device *dev, void *dev_id, > return irq; > } > > +static int init_charge_current_limit(struct device *dev, > + struct gpio_charger *gpio_charger) > +{ > + int i, len; > + u32 cur_limit = U32_MAX; > + > + gpio_charger->current_limit_gpios = devm_gpiod_get_array_optional(dev, > + "charge-current-limit", GPIOD_OUT_LOW); > + if (IS_ERR(gpio_charger->current_limit_gpios)) { > + dev_err(dev, "error getting current-limit GPIOs\n"); > + return PTR_ERR(gpio_charger->current_limit_gpios); > + } > + > + if (!gpio_charger->current_limit_gpios) > + return 0; > + > + len = device_property_read_u32_array(dev, "charge-current-limit-mapping", > + NULL, 0); > + if (len < 0) > + return len; > + > + if (len % 2) { > + dev_err(dev, "invalid charge-current-limit-mapping length\n"); > + return -EINVAL; > + } > + > + gpio_charger->current_limit_map = devm_kmalloc_array(dev, > + len / 2, sizeof(*gpio_charger->current_limit_map), GFP_KERNEL); > + if (!gpio_charger->current_limit_map) > + return -ENOMEM; > + > + gpio_charger->current_limit_map_size = len / 2; > + > + len = device_property_read_u32_array(dev, "charge-current-limit-mapping", > + (u32*) gpio_charger->current_limit_map, len); > + if (len < 0) > + return len; > + > + for (i=0; i < gpio_charger->current_limit_map_size; i++) { > + if (gpio_charger->current_limit_map[i].limit_ua > cur_limit) { > + dev_err(dev, "invalid charge-current-limit-mapping\n"); > + return -EINVAL; > + } > + > + cur_limit = gpio_charger->current_limit_map[i].limit_ua; > + } > + > + /* default to smallest current limitation for safety reasons */ > + len = gpio_charger->current_limit_map_size - 1; > + set_charge_current_limit(gpio_charger, > + gpio_charger->current_limit_map[len].limit_ua); > + > + return 0; > +} > + > +/* > + * The entries will be overwritten by driver's probe routine depending > + * on the available features. This list ensures, that the array is big > + * enough for all optional features. > + */ > static enum power_supply_property gpio_charger_properties[] = { > POWER_SUPPLY_PROP_ONLINE, > - POWER_SUPPLY_PROP_STATUS /* Must always be last in the array. */ > + POWER_SUPPLY_PROP_STATUS, > + POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX, > }; > > static int gpio_charger_probe(struct platform_device *pdev) > @@ -128,6 +260,7 @@ static int gpio_charger_probe(struct platform_device *pdev) > int charge_status_irq; > unsigned long flags; > int ret; > + int num_props = 0; > > if (!pdata && !dev->of_node) { > dev_err(dev, "No platform data\n"); > @@ -137,18 +270,19 @@ static int gpio_charger_probe(struct platform_device *pdev) > gpio_charger = devm_kzalloc(dev, sizeof(*gpio_charger), GFP_KERNEL); > if (!gpio_charger) > return -ENOMEM; > + gpio_charger->dev = dev; > > /* > * This will fetch a GPIO descriptor from device tree, ACPI or > * boardfile descriptor tables. It's good to try this first. > */ > - gpio_charger->gpiod = devm_gpiod_get(dev, NULL, GPIOD_IN); > + gpio_charger->gpiod = devm_gpiod_get_optional(dev, NULL, GPIOD_IN); > > /* > * If this fails and we're not using device tree, try the > * legacy platform data method. > */ > - if (IS_ERR(gpio_charger->gpiod) && !dev->of_node) { > + if (!gpio_charger->gpiod && !dev->of_node) { > /* Non-DT: use legacy GPIO numbers */ > if (!gpio_is_valid(pdata->gpio)) { > dev_err(dev, "Invalid gpio pin in pdata\n"); > @@ -173,18 +307,38 @@ static int gpio_charger_probe(struct platform_device *pdev) > return PTR_ERR(gpio_charger->gpiod); > } > > + if (gpio_charger->gpiod && > + num_props < ARRAY_SIZE(gpio_charger_properties)) { > + gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_ONLINE; > + num_props++; > + } > + > charge_status = devm_gpiod_get_optional(dev, "charge-status", GPIOD_IN); > - gpio_charger->charge_status = charge_status; > - if (IS_ERR(gpio_charger->charge_status)) > - return PTR_ERR(gpio_charger->charge_status); > + if (IS_ERR(charge_status)) > + return PTR_ERR(charge_status); > + if (charge_status && num_props < ARRAY_SIZE(gpio_charger_properties)) { > + gpio_charger->charge_status = charge_status; > + gpio_charger_properties[num_props] = POWER_SUPPLY_PROP_STATUS; > + num_props++; > + } > + > + ret = init_charge_current_limit(dev, gpio_charger); > + if (ret < 0) > + return ret; > + if (gpio_charger->current_limit_map && > + num_props < ARRAY_SIZE(gpio_charger_properties)) { > + gpio_charger_properties[num_props] = > + POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT_MAX; > + num_props++; > + } > > charger_desc = &gpio_charger->charger_desc; > charger_desc->properties = gpio_charger_properties; > - charger_desc->num_properties = ARRAY_SIZE(gpio_charger_properties); > - /* Remove POWER_SUPPLY_PROP_STATUS from the supported properties. */ > - if (!gpio_charger->charge_status) > - charger_desc->num_properties -= 1; > + charger_desc->num_properties = num_props; > charger_desc->get_property = gpio_charger_get_property; > + charger_desc->set_property = gpio_charger_set_property; > + charger_desc->property_is_writeable = > + gpio_charger_property_is_writeable; > > psy_cfg.of_node = dev->of_node; > psy_cfg.drv_data = gpio_charger; > @@ -269,6 +423,6 @@ static struct platform_driver gpio_charger_driver = { > module_platform_driver(gpio_charger_driver); > > MODULE_AUTHOR("Lars-Peter Clausen "); > -MODULE_DESCRIPTION("Driver for chargers which report their online status through a GPIO"); > +MODULE_DESCRIPTION("Driver for chargers only communicating via GPIO(s)"); > MODULE_LICENSE("GPL"); > MODULE_ALIAS("platform:gpio-charger"); > -- > 2.26.2 >