Re: [PATCH-v4 1/3] mfd: 88pm800: Add device tree support

Krzysztof Kozlowski
2015-06-26T06:35:29Z

2015-06-26 14:59 GMT+09:00 Vaibhav Hiremath <vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>:
>
>
> On Friday 26 June 2015 11:23 AM, Yi Zhang wrote:
>>
>> On Thu, Jun 25, 2015 at 08:57:49PM +0530, Vaibhav Hiremath wrote:
>>>
>>>
>>>
>>> On Thursday 25 June 2015 08:18 PM, Lee Jones wrote:
>>>>
>>>> On Thu, 25 Jun 2015, Vaibhav Hiremath wrote:
>>>>>
>>>>> On Thursday 25 June 2015 03:49 PM, Lee Jones wrote:
>>>>>>
>>>>>> On Thu, 25 Jun 2015, Vaibhav Hiremath wrote:
>>>>>>
>>>>>>> Add DT support to the 88pm800 driver, along with compatible
>>>>>>> field for it's sub-devices (rtc, onkey and regulator)
>>>>>>>
>>>>>>> Signed-off-by: Chao Xie <chao.xie-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
>>>>>>> Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
>>>>>>> ---
>>>>>>> drivers/mfd/88pm800.c | 23 +++++++++++++++++++++++
>>>>>>> 1 file changed, 23 insertions(+)
>>>>>>>
>>>>>>> diff --git a/drivers/mfd/88pm800.c b/drivers/mfd/88pm800.c
>>>>>>> index 841717a..40fd014 100644
>>>>>>> --- a/drivers/mfd/88pm800.c
>>>>>>> +++ b/drivers/mfd/88pm800.c
>>>>>>> @@ -27,6 +27,7 @@
>>>>>>> #include <linux/mfd/core.h>
>>>>>>> #include <linux/mfd/88pm80x.h>
>>>>>>> #include <linux/slab.h>
>>>>>>> +#include <linux/of_device.h>
>>>>>>>
>>>>>>> /* Interrupt Registers */
>>>>>>> #define PM800_INT_STATUS1 (0x05)
>>>>>>> @@ -121,6 +122,11 @@ static const struct i2c_device_id
>>>>>>> pm80x_id_table[] = {
>>>>>>> };
>>>>>>> MODULE_DEVICE_TABLE(i2c, pm80x_id_table);
>>>>>>>
>>>>>>> +static const struct of_device_id pm80x_of_match_table[] = {
>>>>>>> + { .compatible = "marvell,88pm800", },
>>>>>>> + {},
>>>>>>> +};
>>>>>>> +
>>>>>>> static struct resource rtc_resources[] = {
>>>>>>> {
>>>>>>> .name = "88pm80x-rtc",
>>>>>>> @@ -133,6 +139,7 @@ static struct resource rtc_resources[] = {
>>>>>>> static struct mfd_cell rtc_devs[] = {
>>>>>>> {
>>>>>>> .name = "88pm80x-rtc",
>>>>>>> + .of_compatible = "marvell,88pm80x-rtc",
>>>>>>> .num_resources = ARRAY_SIZE(rtc_resources),
>>>>>>> .resources = &rtc_resources[0],
>>>>>>> .id = -1,
>>>>>>> @@ -151,6 +158,7 @@ static struct resource onkey_resources[] = {
>>>>>>> static const struct mfd_cell onkey_devs[] = {
>>>>>>> {
>>>>>>> .name = "88pm80x-onkey",
>>>>>>> + .of_compatible = "marvell,88pm80x-onkey",
>>>>>>> .num_resources = 1,
>>>>>>> .resources = &onkey_resources[0],
>>>>>>> .id = -1,
>>>>>>> @@ -160,6 +168,7 @@ static const struct mfd_cell onkey_devs[] = {
>>>>>>> static const struct mfd_cell regulator_devs[] = {
>>>>>>> {
>>>>>>> .name = "88pm80x-regulator",
>>>>>>> + .of_compatible = "marvell,88pm80x-regulator",
>>>>>>> .id = -1,
>>>>>>> },
>>>>>>> };
>>>>>>> @@ -544,8 +553,21 @@ static int pm800_probe(struct i2c_client
>>>>>>> *client,
>>>>>>> int ret = 0;
>>>>>>> struct pm80x_chip *chip;
>>>>>>> struct pm80x_platform_data *pdata =
>>>>>>> dev_get_platdata(&client->dev);
>>>>>>> + struct device_node *np = client->dev.of_node;
>>>>>>> struct pm80x_subchip *subchip;
>>>>>>>
>>>>>>> + if (!pdata && !np) {
>>>>>>> + dev_err(&client->dev,
>>>>>>> + "pm80x requires platform data or of_node\n");
>>>>>>> + return -EINVAL;
>>>>>>> + }
>>>>>>> +
>>>>>>> + if (!pdata) {
>>>>>>> + pdata = devm_kzalloc(&client->dev, sizeof(*pdata),
>>>>>>> GFP_KERNEL);
>>>>>>> + if (!pdata)
>>>>>>> + return -ENOMEM;
>>>>>>> + }
>>>>>>
>>>>>>
>>>>>> Why have you allocated data for pdata, then done nothing with it?
>>>>>>
>>>>>
>>>>> Not in this patch, but subsequent patches would use it.
>>>>
>>>>
>>>> Only provide it when you start using it please.
>>>>
>>>
>>> I will take back my earlier comment of "not using in this patch, but
>>> subsequent patches".
>>>
>>> pdata is being used, couple of places in the driver,
>>>
>>>
>>> @line-751
>>>
>>> ret = device_800_init(chip, pdata);
>>> if (ret) {
>>> dev_err(chip->dev, "Failed to initialize 88pm800
>>> devices\n");
>>> goto err_device_init;
>>> }
>>>
>>> if (pdata && pdata->plat_config)
>>> pdata->plat_config(chip, pdata);
>>
>>
>> this plat_config() is used in legacy non-device-tree code, it's used
>> to implement fixup for chip or board level, it exists in
>> the board configuration file
>>
>> just curious, do you think we still need to keep it?
>> considering device-tree has been used. thanks;
>>
>
> I do not see it anywhere in mainline kernel tree, is it part of some
> internal tree?
>
> If we know that it is being used, then lets not remove it now.

There aren't many board files in mainline but still downstream may use
it. Do you know who could be the downstream for this device?

Best regards,
Krzysztof