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

From: Chris Lapa
Date: Mon Jun 13 2016 - 21:51:08 EST


Hi Krzysztof,

Appreciate the feedback, working on the fixups you pointed out now.

I'll ensure I send v3 of the patches to the actual maintainers and not just the list. Still getting my head around the lists mechanics :)

Thanks,
Chris:

On 11/06/2016 12:02 AM, Krzysztof Kozlowski wrote:
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