Re: [PATCH 1/2] max8903: adds support for initiation via device tree.

From: Chris Lapa
Date: Fri Jun 10 2016 - 01:35:55 EST


Hi Krzysztof,

Thanks for the review. I'm working on those changes now.

However just so I know for the future. Why no error checking on devm_kzalloc() result? Looking through the source for devm_kzalloc() it looks like NULL isn't caught anywhere else.

Thanks,
Chris

On 9/06/2016 8:35 PM, Krzysztof Kozlowski wrote:
Hi,

Thanks for your contribution. Few comments below:

On Thu, Jun 2, 2016 at 8:44 AM, <chris@xxxxxxxxxxx> 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>
---
.../devicetree/bindings/power/max8903-charger.txt | 28 ++
drivers/power/max8903_charger.c | 281 ++++++++++++++++-----
2 files changed, 250 insertions(+), 59 deletions(-)
create mode 100644 Documentation/devicetree/bindings/power/max8903-charger.txt

Please put the bindings documentation in separate, first patch.


diff --git a/Documentation/devicetree/bindings/power/max8903-charger.txt b/Documentation/devicetree/bindings/power/max8903-charger.txt
new file mode 100644
index 0000000..7207731
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/max8903-charger.txt
@@ -0,0 +1,28 @@
+Maxim Semiconductor MAX8903 Battery Charger bindings
+
+Required properties:
+- compatible: "max8903-charger" for MAX8903 Battery Charger

Needs a 'maxim,' prefix.

+- dc_valid:
+ - dok: DC power OK pin
+- usb_valid:
+ - uok: USB power OK pin

I don't understand the explanation of them - dok/uok. What do you want
to say here?

+
+Optional properties:
+- cen: Charge enable pin
+- chg: Charger status pin
+- flt: Fault pin
+- dcm: Current limit mode setting (DC or USB)
+- usus: USB suspend pin

Each gpio should be suffixed with '-gpios' (see
Documentation/devicetree/bindings/gpio/gpio.txt).

+
+
+Example:
+
+ max8903-charger {
+ compatible = "max8903-charger";
+ dok = <&gpio2 3 GPIO_ACTIVE_LOW>;
+ flt = <&gpio2 2 GPIO_ACTIVE_LOW>;
+ chg = <&gpio3 15 GPIO_ACTIVE_LOW>;
+ cen = <&gpio2 5 GPIO_ACTIVE_LOW>;
+ dc_valid;
+ status = "okay";
+ };
diff --git a/drivers/power/max8903_charger.c b/drivers/power/max8903_charger.c
index 17876ca..1989c10 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;
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;
@@ -179,34 +183,135 @@ 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;
+ }

Run a scripts/checkpatch.pl. In general the {} are not needed for
single statements.

+
+ pdata = devm_kzalloc(dev, sizeof(struct max8903_pdata),
+ GFP_KERNEL);
+ if (!pdata) {
+ return pdata;

ditto

+ }
+
+ 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", 0);
+ if (!gpio_is_valid(pdata->cen)) {
+ pdata->cen = 0;
+ }
+
+ pdata->chg = of_get_named_gpio(of_node, "chg", 0);
+ if (!gpio_is_valid(pdata->chg)) {
+ pdata->chg = 0;
+ }
+
+ pdata->flt = of_get_named_gpio(of_node, "flt", 0);
+ if (!gpio_is_valid(pdata->flt)) {
+ pdata->flt = 0;
+ }
+
+ pdata->usus = of_get_named_gpio(of_node, "usus", 0);
+ if (!gpio_is_valid(pdata->usus)) {
+ pdata->usus = 0;
+ }
+
+ pdata->dcm = of_get_named_gpio(of_node, "dcm", 0);
+ if (!gpio_is_valid(pdata->dcm)) {
+ pdata->dcm = 0;
+ }
+
+ pdata->dok = of_get_named_gpio(of_node, "dok", 0);
+ if (!gpio_is_valid(pdata->dok)) {
+ pdata->dok = 0;
+ }
+
+ pdata->uok = of_get_named_gpio(of_node, "uok", 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");

In a separate patch - you can get rid of error message.

I didn't perform a thorough review. First fix some easy ones. :)

Best regards,
Krzysztof