Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754575AbbFBKTH (ORCPT ); Tue, 2 Jun 2015 06:19:07 -0400 Received: from mail-pa0-f47.google.com ([209.85.220.47]:35226 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752845AbbFBKS7 (ORCPT ); Tue, 2 Jun 2015 06:18:59 -0400 Message-ID: <556D82FE.4010102@linaro.org> Date: Tue, 02 Jun 2015 15:48:38 +0530 From: Vaibhav Hiremath User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: Lee Jones CC: linux-arm-kernel@lists.infradead.org, robh+dt@kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, sameo@linux.intel.com, a.zummo@towertech.it, alexandre.belloni@free-electrons.com, Chao Xie Subject: Re: [PATCH 4/4] mfd: 88pm800: allocate pdata->rtc if not allocated earlier References: <1432937962-4537-1-git-send-email-vaibhav.hiremath@linaro.org> <1432937962-4537-5-git-send-email-vaibhav.hiremath@linaro.org> <20150601082200.GC3329@x1> <556D3A14.6050505@linaro.org> <20150602074004.GH3329@x1> <556D71F6.4030608@linaro.org> <20150602093323.GI3329@x1> <556D7C32.9080806@linaro.org> <20150602100739.GK3329@x1> In-Reply-To: <20150602100739.GK3329@x1> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4896 Lines: 130 On Tuesday 02 June 2015 03:37 PM, Lee Jones wrote: > On Tue, 02 Jun 2015, Vaibhav Hiremath wrote: >> On Tuesday 02 June 2015 03:03 PM, Lee Jones wrote: >>> On Tue, 02 Jun 2015, Vaibhav Hiremath wrote: >>>> On Tuesday 02 June 2015 01:10 PM, Lee Jones wrote: >>>>> On Tue, 02 Jun 2015, Vaibhav Hiremath wrote: >>>>>> On Monday 01 June 2015 01:52 PM, Lee Jones wrote: >>>>>>> On Sat, 30 May 2015, Vaibhav Hiremath wrote: >>>>>>> >>>>>>>> RTC in pmic 88PM800 can run even the core is powered off, and user >>>>>>>> can set alarm in RTC. When the alarm is timed out, the PMIC will power up >>>>>>>> the core, and the whole system will boot up. And during PMIC driver probe, >>>>>>>> it will read some register to find out whether this boot is caused by RTC >>>>>>>> timeout or not, and pass on this information to the RTC driver. >>>>>>>> >>>>>>>> So we need rtc platform data to be existed in PMIC driver to pass this >>>>>>>> information. >>>>>>>> >>>>>>>> Signed-off-by: Chao Xie >>>>>>>> Signed-off-by: Vaibhav Hiremath >>>>>>>> --- >>>>>>>> drivers/mfd/88pm800.c | 19 +++++++++++++++++++ >>>>>>>> 1 file changed, 19 insertions(+) >>>>>>>> >>>>>>>> diff --git a/drivers/mfd/88pm800.c b/drivers/mfd/88pm800.c >>>>>>>> index 8ea4467..34546a1 100644 >>>>>>>> --- a/drivers/mfd/88pm800.c >>>>>>>> +++ b/drivers/mfd/88pm800.c >>>>>>>> @@ -586,6 +586,25 @@ static int pm800_probe(struct i2c_client *client, >>>>>>>> return ret; >>>>>>>> } >>>>>>>> >>>>>>>> + /* >>>>>>>> + * RTC in pmic can run even the core is powered off, and user can set >>>>>>>> + * alarm in RTC. When the alarm is time out, the PMIC will power up >>>>>>>> + * the core, and the whole system will boot up. When PMIC driver is >>>>>>>> + * probed, it will read out some register to find out whether this >>>>>>>> + * boot is caused by RTC timeout or not, and it need pass this >>>>>>>> + * information to RTC driver. >>>>>>>> + * So we need rtc platform data to be existed to pass this information. >>>>>>>> + */ >>>>>>>> + if (!pdata->rtc) { >>>>>>>> + pdata->rtc = devm_kzalloc(&client->dev, >>>>>>>> + sizeof(*(pdata->rtc)), GFP_KERNEL); >>>>>>>> + if (!pdata->rtc) { >>>>>>>> + dev_err(&client->dev, >>>>>>>> + "failed to allocate memory for rtc\n"); >>>>>>>> + return -ENOMEM; >>>>>>>> + } >>>>>>>> + } >>>>>>>> + >>>>>>> >>>>>>> Where is this memory first used? >>>>>>> >>>>>> >>>>>> In the same file, look for field "rtc_wakeup". >>>>>> >>>>>> FYI, >>>>>> >>>>>> This field is used in two files, >>>>>> >>>>>> drivers/mfd/88pm800.c >>>>>> and >>>>>> drivers/rtc/rtc-88pm800.c [sets the "platform_data" field] >>>>> >>>>> Then were is the platform_data field subsequently used? >>>> >>>> Currently not used, but it is for future use, where we would be >>>> interested to know that the wakeup is really from reset or RTC wakeup. >>> >>> Well it was introduced 3 years ago, so the chances of it being "used >>> in the future" are probably pretty low. Unless of course, you are >>> planning on submitting that code. In which case, you can add this >>> patch to that set and I can re-review it then. >>> >>>>> Looking at the RTC platform data declaration I see: >>>>> >>>>> struct pm80x_rtc_pdata { >>>>> int vrtc; >>>>> int rtc_wakeup; >>>>> }; >>>>> >>>>> Is 'vrtc' even used? If so, where? >>>> >>>> No, it is not. >>> >>> So either submit a patch-set that makes use of them, or let me know >>> that you're not going to do that and I'll remove it altogether. >>> Likewise for rtc_wakeup. >>> >> >> I am ok with vrtc field, we can remove it. > > Okay, I will do so, thanks. > >> But, >> I would recommend _not_ to remove rtc_wakeup, as it may not be used >> immediately, but still have logical significance. >> >> Consuming rtc_wakeup in the code is dependant on overall power >> management support, which is always long pole for development. As you >> would have seen, we have just started with baseport for pxa1928 and I >> am starting on upstreaming driver part. >> >> >> From hardware perspective, this is important feature, where it indicate >> whether the boot was triggered by reset assertion or by RTC wakeup. So >> as of now from driver perspective I feel no harm to have one field for >> this. >> >> Finally, its your call. I will let you decide. >> The field can be added later when it actually gets consumed. > > I will not remove the wake-up field. Equally, I will not accept code > which allocates memory for it whilst it is not being used. > Not an issue. As I said, it can be added later when we actually consume it. Thanks, Vaibhav -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/