Re: [PATCH v2 2/4] max8903: adds support for initiation via device tree.

From: Krzysztof Kozlowski
Date: Fri Jun 10 2016 - 10:03:12 EST


On 06/10/2016 02:32 PM, Chris Lapa wrote:
> From: Chris Lapa <chris@xxxxxxxxxxx>
>
> This commit also adds requesting gpio's via devm_gpio_request() to ensure
> the gpio is available for usage by the driver.
>
> Signed-off-by: Chris Lapa <chris@xxxxxxxxxxx>
> ---
> drivers/power/max8903_charger.c | 288 +++++++++++++++++++++++++++++++---------
> 1 file changed, 225 insertions(+), 63 deletions(-)
>
> diff --git a/drivers/power/max8903_charger.c b/drivers/power/max8903_charger.c
> index 17876ca..d7544c8 100644
> --- a/drivers/power/max8903_charger.c
> +++ b/drivers/power/max8903_charger.c
> @@ -23,13 +23,16 @@
> #include <linux/gpio.h>
> #include <linux/interrupt.h>
> #include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/of_gpio.h>
> #include <linux/slab.h>
> #include <linux/power_supply.h>
> #include <linux/platform_device.h>
> #include <linux/power/max8903_charger.h>
>
> struct max8903_data {
> - struct max8903_pdata pdata;
> + struct max8903_pdata *pdata;

Please split the conversion to '*pdata' to separate patch. It obfuscates
a lot the patch so it is difficult to find the DT changes.

> struct device *dev;
> struct power_supply *psy;
> struct power_supply_desc psy_desc;
> @@ -53,8 +56,8 @@ static int max8903_get_property(struct power_supply *psy,
> switch (psp) {
> case POWER_SUPPLY_PROP_STATUS:
> val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
> - if (data->pdata.chg) {
> - if (gpio_get_value(data->pdata.chg) == 0)
> + if (data->pdata->chg) {
> + if (gpio_get_value(data->pdata->chg) == 0)
> val->intval = POWER_SUPPLY_STATUS_CHARGING;
> else if (data->usb_in || data->ta_in)
> val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> @@ -75,13 +78,14 @@ static int max8903_get_property(struct power_supply *psy,
> default:
> return -EINVAL;
> }
> +
> return 0;
> }
>
> static irqreturn_t max8903_dcin(int irq, void *_data)
> {
> struct max8903_data *data = _data;
> - struct max8903_pdata *pdata = &data->pdata;
> + struct max8903_pdata *pdata = data->pdata;
> bool ta_in;
> enum power_supply_type old_type;
>
> @@ -122,7 +126,7 @@ static irqreturn_t max8903_dcin(int irq, void *_data)
> static irqreturn_t max8903_usbin(int irq, void *_data)
> {
> struct max8903_data *data = _data;
> - struct max8903_pdata *pdata = &data->pdata;
> + struct max8903_pdata *pdata = data->pdata;
> bool usb_in;
> enum power_supply_type old_type;
>
> @@ -161,7 +165,7 @@ static irqreturn_t max8903_usbin(int irq, void *_data)
> static irqreturn_t max8903_fault(int irq, void *_data)
> {
> struct max8903_data *data = _data;
> - struct max8903_pdata *pdata = &data->pdata;
> + struct max8903_pdata *pdata = data->pdata;
> bool fault;
>
> fault = gpio_get_value(pdata->flt) ? false : true;
> @@ -179,38 +183,132 @@ static irqreturn_t max8903_fault(int irq, void *_data)
> return IRQ_HANDLED;
> }
>
> +static struct max8903_pdata *max8903_parse_dt_data(
> + struct device *dev)
> +{
> + struct device_node *of_node = dev->of_node;
> + struct max8903_pdata *pdata = NULL;
> +
> + if (!of_node)
> + return pdata;
> +

Unnecessary blank line.

Just "return NULL", it is easier to read such code (no need to double
check if pdata was initialized or not).

> +
> + pdata = devm_kzalloc(dev, sizeof(struct max8903_pdata),

sizeof(*pdata)

> + GFP_KERNEL);
> + if (!pdata)
> + return pdata;

Ditto, return NULL.

> +
> + if (of_get_property(of_node, "dc_valid", NULL))
> + pdata->dc_valid = true;
> +
> + if (of_get_property(of_node, "usb_valid", NULL))
> + pdata->usb_valid = true;
> +
> + pdata->cen = of_get_named_gpio(of_node, "cen-gpios", 0);
> + if (!gpio_is_valid(pdata->cen))
> + pdata->cen = 0;

0 could be a valid GPIO so probably you want:
pdata->cen = -EINVAL;

> +
> + pdata->chg = of_get_named_gpio(of_node, "chg-gpios", 0);
> + if (!gpio_is_valid(pdata->chg))
> + pdata->chg = 0;
> +
> + pdata->flt = of_get_named_gpio(of_node, "flt-gpios", 0);
> + if (!gpio_is_valid(pdata->flt))
> + pdata->flt = 0;
> +
> + pdata->usus = of_get_named_gpio(of_node, "usus-gpios", 0);
> + if (!gpio_is_valid(pdata->usus))
> + pdata->usus = 0;
> +
> + pdata->dcm = of_get_named_gpio(of_node, "dcm-gpios", 0);
> + if (!gpio_is_valid(pdata->dcm))
> + pdata->dcm = 0;
> +
> + pdata->dok = of_get_named_gpio(of_node, "dok-gpios", 0);
> + if (!gpio_is_valid(pdata->dok))
> + pdata->dok = 0;
> +
> + pdata->uok = of_get_named_gpio(of_node, "uok-gpios", 0);
> + if (!gpio_is_valid(pdata->uok))
> + pdata->uok = 0;
> +
> + return pdata;
> +}
> +
> static int max8903_probe(struct platform_device *pdev)
> {
> - struct max8903_data *data;
> + struct max8903_data *charger;
> struct device *dev = &pdev->dev;
> - struct max8903_pdata *pdata = pdev->dev.platform_data;
> struct power_supply_config psy_cfg = {};
> int ret = 0;
> int gpio;
> int ta_in = 0;
> int usb_in = 0;
>
> - data = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
> - if (data == NULL) {
> + charger = devm_kzalloc(dev, sizeof(struct max8903_data), GFP_KERNEL);
> + if (charger == NULL) {
> dev_err(dev, "Cannot allocate memory.\n");
> return -ENOMEM;
> }
> - memcpy(&data->pdata, pdata, sizeof(struct max8903_pdata));
> - data->dev = dev;
> - platform_set_drvdata(pdev, data);
>
> - if (pdata->dc_valid == false && pdata->usb_valid == false) {
> + charger->pdata = pdev->dev.platform_data;
> + if (IS_ENABLED(CONFIG_OF) && !charger->pdata && dev->of_node) {
> + charger->pdata = max8903_parse_dt_data(dev);
> + if (!charger->pdata)
> + return -EINVAL;
> + }
> +
> + charger->dev = dev;
> +
> + platform_set_drvdata(pdev, charger);
> +
> + charger->fault = false;
> + charger->ta_in = ta_in;
> + charger->usb_in = usb_in;
> +
> + charger->psy_desc.name = "max8903_charger";
> + charger->psy_desc.type = (ta_in) ? POWER_SUPPLY_TYPE_MAINS :
> + ((usb_in) ? POWER_SUPPLY_TYPE_USB :
> + POWER_SUPPLY_TYPE_BATTERY);
> + charger->psy_desc.get_property = max8903_get_property;
> + charger->psy_desc.properties = max8903_charger_props;
> + charger->psy_desc.num_properties = ARRAY_SIZE(max8903_charger_props);
> +
> + if (charger->pdata->dc_valid == false &&
> + charger->pdata->usb_valid == false) {
> dev_err(dev, "No valid power sources.\n");
> return -EINVAL;
> }
>
> - if (pdata->dc_valid) {
> - if (pdata->dok && gpio_is_valid(pdata->dok) &&
> - pdata->dcm && gpio_is_valid(pdata->dcm)) {
> - gpio = pdata->dok; /* PULL_UPed Interrupt */
> + if (charger->pdata->dc_valid) {
> + if (charger->pdata->dok &&
> + gpio_is_valid(charger->pdata->dok) &&
> + charger->pdata->dcm &&
> + gpio_is_valid(charger->pdata->dcm)) {
> + ret = devm_gpio_request(dev,
> + charger->pdata->dok,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for dok: %d err %d\n",
> + charger->pdata->dok, ret);
> + return -EINVAL;
> + }
> +
> + ret = devm_gpio_request(dev,
> + charger->pdata->dcm,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for dcm: %d err %d\n",
> + charger->pdata->dcm, ret);
> + return -EINVAL;
> + }
> +
> + gpio = charger->pdata->dok; /* PULL_UPed Interrupt */
> ta_in = gpio_get_value(gpio) ? 0 : 1;
>
> - gpio = pdata->dcm; /* Output */
> + gpio = charger->pdata->dcm; /* Output */
> gpio_set_value(gpio, ta_in);
> } else {
> dev_err(dev, "When DC is wired, DOK and DCM should"
> @@ -218,19 +316,39 @@ static int max8903_probe(struct platform_device *pdev)
> return -EINVAL;
> }
> } else {
> - if (pdata->dcm) {
> - if (gpio_is_valid(pdata->dcm))
> - gpio_set_value(pdata->dcm, 0);
> - else {
> + if (charger->pdata->dcm) {
> + if (gpio_is_valid(charger->pdata->dcm)) {
> + ret = devm_gpio_request(dev,
> + charger->pdata->dcm,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for dcm: %d err %d\n",
> + charger->pdata->dcm, ret);
> + return -EINVAL;
> + }
> +
> + gpio_set_value(charger->pdata->dcm, 0);
> + } else {
> dev_err(dev, "Invalid pin: dcm.\n");
> return -EINVAL;
> }
> }
> }
>
> - if (pdata->usb_valid) {
> - if (pdata->uok && gpio_is_valid(pdata->uok)) {
> - gpio = pdata->uok;
> + if (charger->pdata->usb_valid) {
> + if (gpio_is_valid(charger->pdata->uok)) {
> + ret = devm_gpio_request(dev,
> + charger->pdata->uok,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for uok: %d err %d\n",
> + charger->pdata->uok, ret);
> + return -EINVAL;
> + }
> +
> + gpio = charger->pdata->uok;
> usb_in = gpio_get_value(gpio) ? 0 : 1;
> } else {
> dev_err(dev, "When USB is wired, UOK should be wired."
> @@ -239,91 +357,128 @@ static int max8903_probe(struct platform_device *pdev)
> }
> }
>
> - if (pdata->cen) {
> - if (gpio_is_valid(pdata->cen)) {
> - gpio_set_value(pdata->cen, (ta_in || usb_in) ? 0 : 1);
> + if (charger->pdata->cen) {
> + if (gpio_is_valid(charger->pdata->cen)) {
> + ret = devm_gpio_request(dev,
> + charger->pdata->cen,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for cen: %d err %d\n",
> + charger->pdata->cen, ret);
> + return -EINVAL;
> + }
> +
> + gpio_set_value(charger->pdata->cen,
> + (ta_in || usb_in) ? 0 : 1);
> } else {
> dev_err(dev, "Invalid pin: cen.\n");
> return -EINVAL;
> }
> }
>
> - if (pdata->chg) {
> - if (!gpio_is_valid(pdata->chg)) {
> + if (charger->pdata->chg) {
> + if (gpio_is_valid(charger->pdata->chg)) {
> + ret = devm_gpio_request(dev,
> + charger->pdata->chg,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for chg: %d err %d\n",
> + charger->pdata->chg, ret);
> + return -EINVAL;
> + }
> + } else {
> dev_err(dev, "Invalid pin: chg.\n");
> return -EINVAL;
> }
> }
>
> - if (pdata->flt) {
> - if (!gpio_is_valid(pdata->flt)) {
> + if (charger->pdata->flt) {
> + if (gpio_is_valid(charger->pdata->flt)) {
> + ret = devm_gpio_request(dev,
> + charger->pdata->flt,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for flt: %d err %d\n",
> + charger->pdata->flt, ret);
> + return -EINVAL;
> + }
> + } else {
> dev_err(dev, "Invalid pin: flt.\n");
> return -EINVAL;
> }
> }
>
> - if (pdata->usus) {
> - if (!gpio_is_valid(pdata->usus)) {
> + if (charger->pdata->usus) {
> + if (gpio_is_valid(charger->pdata->usus)) {
> + ret = devm_gpio_request(dev,
> + charger->pdata->usus,
> + charger->psy_desc.name);
> + if (ret) {
> + dev_err(dev,
> + "Failed GPIO request for usus: %d err %d\n",
> + charger->pdata->usus, ret);
> + return -EINVAL;
> + }
> + } else {
> dev_err(dev, "Invalid pin: usus.\n");
> return -EINVAL;
> }
> }
>
> - data->fault = false;
> - data->ta_in = ta_in;
> - data->usb_in = usb_in;
> + psy_cfg.supplied_to = NULL;
> + psy_cfg.num_supplicants = 0;

Why? This is already set to 0. Additionally this does not look needded
for conversion to DT. Please split out all unrelated changes to separate
patches. It could be organized as:
patch #1: Document DT bindings.
patch #2: Some fix needed.
patch #3: Some other cleanup
patch #4: Store pointer to pdata instead of copying it
patch #5: Add support for Device Tree

Best regards,
Krzysztof