2014-06-17 04:01:00

by George Cherian

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Subject: [PATCH 0/2] Add devicetree support for extcon-gpio

This serires adds devicetree support for extcon-gpio driver.

Patch 1 - Addreses minor cleanups
Patch 2 - Adds devicetree support for esxtcon-gpio driver.

George Cherian (2):
extcon: gpio: Minor cleanups
extcon: gpio: Add dt support for the driver.

.../devicetree/bindings/extcon/extcon-gpio.txt | 34 +++++++++++++++++++
drivers/extcon/extcon-gpio.c | 39 +++++++++++++++++++---
include/linux/extcon/extcon-gpio.h | 4 ++-
3 files changed, 71 insertions(+), 6 deletions(-)
create mode 100644 Documentation/devicetree/bindings/extcon/extcon-gpio.txt

--
1.8.3.1


2014-06-17 04:01:03

by George Cherian

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Subject: [PATCH 1/2] extcon: gpio: Minor cleanups

Minor Cleanups
- Order the include files in alphabetical order.
- Fix description of state_off in extcon_gpio.h
- Add a descrition for check_on_resume in extcon_gpio.h

Signed-off-by: George Cherian <[email protected]>
---
drivers/extcon/extcon-gpio.c | 10 +++++-----
include/linux/extcon/extcon-gpio.h | 4 +++-
2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
index 645b283..6c268b4 100644
--- a/drivers/extcon/extcon-gpio.c
+++ b/drivers/extcon/extcon-gpio.c
@@ -20,16 +20,16 @@
*
*/

-#include <linux/module.h>
-#include <linux/kernel.h>
+#include <linux/extcon.h>
+#include <linux/extcon/extcon-gpio.h>
+#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
-#include <linux/gpio.h>
-#include <linux/extcon.h>
-#include <linux/extcon/extcon-gpio.h>

struct gpio_extcon_data {
struct extcon_dev *edev;
diff --git a/include/linux/extcon/extcon-gpio.h b/include/linux/extcon/extcon-gpio.h
index 8900fdf..0b17ad4 100644
--- a/include/linux/extcon/extcon-gpio.h
+++ b/include/linux/extcon/extcon-gpio.h
@@ -34,8 +34,10 @@
* @irq_flags: IRQ Flags (e.g., IRQF_TRIGGER_LOW).
* @state_on: print_state is overriden with state_on if attached.
* If NULL, default method of extcon class is used.
- * @state_off: print_state is overriden with state_on if detached.
+ * @state_off: print_state is overriden with state_off if detached.
* If NUll, default method of extcon class is used.
+ * @check_on_resume: Boolean describing whether to check the state of gpio
+ * while resuming from sleep.
*
* Note that in order for state_on or state_off to be valid, both state_on
* and state_off should be not NULL. If at least one of them is NULL,
--
1.8.3.1

2014-06-17 04:01:11

by George Cherian

[permalink] [raw]
Subject: [PATCH 2/2] extcon: gpio: Add dt support for the driver.

Add device tree support to extcon-gpio driver.
Add devicetree binding documentation

Signed-off-by: George Cherian <[email protected]>
---
.../devicetree/bindings/extcon/extcon-gpio.txt | 34 ++++++++++++++++++++++
drivers/extcon/extcon-gpio.c | 29 ++++++++++++++++++
2 files changed, 63 insertions(+)
create mode 100644 Documentation/devicetree/bindings/extcon/extcon-gpio.txt

diff --git a/Documentation/devicetree/bindings/extcon/extcon-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
new file mode 100644
index 0000000..80b791b
--- /dev/null
+++ b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
@@ -0,0 +1,34 @@
+GPIO based EXTCON
+
+EXTCON GPIO
+-----------
+
+Required Properties:
+ - compatible: should be:
+ * "ti,extcon-gpio"
+ - gpios: specifies the gpio pin used.
+ - debounce: Debounce time for GPIO IRQ in ms
+ - irq-flags: IRQ flag to be used ( eg: IRQ_TYPE_EDGE_FALLING)
+
+Optional Properties:
+ - gpio-active-low: Property describing whether gpio active state is 1 or 0
+ If defined , low state of gpio means active.
+ - check-on-resume: Property describing whether to check the gpio state
+ while resuming from SLEEP.
+ - state-on: print_state is overriden with state_on string if provided.
+ If NULL, default method of extcon class is used.
+ - state_off: print_state is overriden with state_off string if provided.
+ If NUll, default method of extcon class is used.
+
+Eg:
+
+ extcon1: am43_usbid_extcon1 {
+ compatible = "ti,extcon-gpio";
+ gpios = <&gpio3 12 GPIO_ACTIVE_HIGH>;
+ gpio-active-low;
+ debounce = <20>;
+ irq-flags = <IRQ_TYPE_EDGE_FALLING>;
+ state-on = "USB ID FLOAT";
+ state-off = "USB ID GND";
+
+ };
diff --git a/drivers/extcon/extcon-gpio.c b/drivers/extcon/extcon-gpio.c
index 6c268b4..14d999d 100644
--- a/drivers/extcon/extcon-gpio.c
+++ b/drivers/extcon/extcon-gpio.c
@@ -27,6 +27,7 @@
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
+#include <linux/of_gpio.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
@@ -83,12 +84,34 @@ static ssize_t extcon_gpio_print_state(struct extcon_dev *edev, char *buf)

static int gpio_extcon_probe(struct platform_device *pdev)
{
+ struct device_node *np = pdev->dev.of_node;
struct gpio_extcon_platform_data *pdata = dev_get_platdata(&pdev->dev);
struct gpio_extcon_data *extcon_data;
int ret;

+ if (np) {
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ pdata->gpio = of_get_gpio(np, 0);
+ if (!gpio_is_valid(pdata->gpio))
+ return -EPROBE_DEFER;
+
+ pdata->name = np->name;
+ pdata->gpio_active_low = of_property_read_bool(np,
+ "gpio-active-low");
+ pdata->check_on_resume = of_property_read_bool(np,
+ "check-on-resume");
+ of_property_read_u32(np, "debounce", (u32 *)&pdata->debounce);
+ of_property_read_u32(np, "irq-flags", (u32 *)&pdata->irq_flags);
+ of_property_read_string(np, "state-on", &pdata->state_on);
+ of_property_read_string(np, "state-off", &pdata->state_off);
+ }
+
if (!pdata)
return -EBUSY;
+
if (!pdata->irq_flags) {
dev_err(&pdev->dev, "IRQ flag is not specified.\n");
return -EINVAL;
@@ -177,6 +200,11 @@ static int gpio_extcon_resume(struct device *dev)

static SIMPLE_DEV_PM_OPS(gpio_extcon_pm_ops, NULL, gpio_extcon_resume);

+static struct of_device_id of_extcon_gpio_match_tbl[] = {
+ { .compatible = "ti,extcon-gpio", },
+ { /* end */ }
+};
+
static struct platform_driver gpio_extcon_driver = {
.probe = gpio_extcon_probe,
.remove = gpio_extcon_remove,
@@ -184,6 +212,7 @@ static struct platform_driver gpio_extcon_driver = {
.name = "extcon-gpio",
.owner = THIS_MODULE,
.pm = &gpio_extcon_pm_ops,
+ .of_match_table = of_extcon_gpio_match_tbl,
},
};

--
1.8.3.1

2014-06-17 15:58:24

by Mark Rutland

[permalink] [raw]
Subject: Re: [PATCH 2/2] extcon: gpio: Add dt support for the driver.

On Tue, Jun 17, 2014 at 04:58:20AM +0100, George Cherian wrote:
> Add device tree support to extcon-gpio driver.
> Add devicetree binding documentation
>
> Signed-off-by: George Cherian <[email protected]>
> ---
> .../devicetree/bindings/extcon/extcon-gpio.txt | 34 ++++++++++++++++++++++
> drivers/extcon/extcon-gpio.c | 29 ++++++++++++++++++
> 2 files changed, 63 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/extcon/extcon-gpio.txt
>
> diff --git a/Documentation/devicetree/bindings/extcon/extcon-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
> new file mode 100644
> index 0000000..80b791b
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
> @@ -0,0 +1,34 @@
> +GPIO based EXTCON
> +
> +EXTCON GPIO
> +-----------
> +
> +Required Properties:
> + - compatible: should be:
> + * "ti,extcon-gpio"
> + - gpios: specifies the gpio pin used.
> + - debounce: Debounce time for GPIO IRQ in ms
> + - irq-flags: IRQ flag to be used ( eg: IRQ_TYPE_EDGE_FALLING)

This looks distinctly odd. Why do you need this here?

> +Optional Properties:
> + - gpio-active-low: Property describing whether gpio active state is 1 or 0
> + If defined , low state of gpio means active.

Surely this is defined in the gpio flags?

> + - check-on-resume: Property describing whether to check the gpio state
> + while resuming from SLEEP.

Does this need to be in DT? Surely we could jsut always check this?

> + - state-on: print_state is overriden with state_on string if provided.
> + If NULL, default method of extcon class is used.
> + - state_off: print_state is overriden with state_off string if provided.
> + If NUll, default method of extcon class is used.

This means nothing from a HW perspective. This describes linux internal
details.

[...]

> + of_property_read_u32(np, "debounce", (u32 *)&pdata->debounce);
> + of_property_read_u32(np, "irq-flags", (u32 *)&pdata->irq_flags);

If you need theses casts, the code is broken.

These functions can only read into a u32. If you pass a smaller type
you'll trash aribtrary memory locations, and if you pass a larger type
this is broken for BE.

Mark.

2014-06-19 03:31:20

by George Cherian

[permalink] [raw]
Subject: Re: [PATCH 2/2] extcon: gpio: Add dt support for the driver.

On 6/17/2014 9:27 PM, Mark Rutland wrote:
> On Tue, Jun 17, 2014 at 04:58:20AM +0100, George Cherian wrote:
>> Add device tree support to extcon-gpio driver.
>> Add devicetree binding documentation
>>
>> Signed-off-by: George Cherian <[email protected]>
>> ---
>> .../devicetree/bindings/extcon/extcon-gpio.txt | 34 ++++++++++++++++++++++
>> drivers/extcon/extcon-gpio.c | 29 ++++++++++++++++++
>> 2 files changed, 63 insertions(+)
>> create mode 100644 Documentation/devicetree/bindings/extcon/extcon-gpio.txt
>>
>> diff --git a/Documentation/devicetree/bindings/extcon/extcon-gpio.txt b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
>> new file mode 100644
>> index 0000000..80b791b
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/extcon/extcon-gpio.txt
>> @@ -0,0 +1,34 @@
>> +GPIO based EXTCON
>> +
>> +EXTCON GPIO
>> +-----------
>> +
>> +Required Properties:
>> + - compatible: should be:
>> + * "ti,extcon-gpio"
>> + - gpios: specifies the gpio pin used.
>> + - debounce: Debounce time for GPIO IRQ in ms
>> + - irq-flags: IRQ flag to be used ( eg: IRQ_TYPE_EDGE_FALLING)
> This looks distinctly odd. Why do you need this here?
The driver takes this as part of platform data. It never continues
operation if
an invalid irq-flag is supplied. Also these can be used for different SoC's
whose GPIO's might support IRQ_TYPE_EDGE_FALLING/RISING.
Now since this is based on gpio we cant up front give a seperate
"interrupts = " property, since we dont know the gpio-pin irq number.

Chanwoo any comments?
>
>> +Optional Properties:
>> + - gpio-active-low: Property describing whether gpio active state is 1 or 0
>> + If defined , low state of gpio means active.
> Surely this is defined in the gpio flags?

Yes, I will make necessary changes.
>
>> + - check-on-resume: Property describing whether to check the gpio state
>> + while resuming from SLEEP.
> Does this need to be in DT? Surely we could jsut always check this?
okay. For my use-case I dont need this.
Chanwoo, any comments?
>> + - state-on: print_state is overriden with state_on string if provided.
>> + If NULL, default method of extcon class is used.
>> + - state_off: print_state is overriden with state_off string if provided.
>> + If NUll, default method of extcon class is used.
> This means nothing from a HW perspective. This describes linux internal
> details.
You mean to say this should not be part of dt?

> [...]
>
>> + of_property_read_u32(np, "debounce", (u32 *)&pdata->debounce);
>> + of_property_read_u32(np, "irq-flags", (u32 *)&pdata->irq_flags);
> If you need theses casts, the code is broken.
I dont need this, will remove in v2.
>
> These functions can only read into a u32. If you pass a smaller type
> you'll trash aribtrary memory locations, and if you pass a larger type
> this is broken for BE.
true.
> Mark.


--
-George