From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751178AbeEBCbZ (ORCPT ); Tue, 1 May 2018 22:31:25 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:38432 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750823AbeEBCbX (ORCPT ); Tue, 1 May 2018 22:31:23 -0400 X-UUID: 914cbf84988f4b9795b1de7e2584b0f7-20180502 Message-ID: <1525228271.14792.5.camel@mtkswgap22> Subject: Re: Re: [PATCH v2 15/17] power: reset: mt6323: add a driver for MT6323 power controller From: Sean Wang To: Sebastian Reichel CC: , , , , , , , , , , , , Date: Wed, 2 May 2018 10:31:11 +0800 In-Reply-To: <20180501125628.44nyx25tqsrxkvsl@earth.universe> References: <51d4fbe0d6a22986ddd2df66c9db39aa1eaab74a.1524646231.git.sean.wang@mediatek.com> <20180501125628.44nyx25tqsrxkvsl@earth.universe> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-05-01 at 14:56 +0200, Sebastian Reichel wrote: > Hi, > > On Wed, Apr 25, 2018 at 05:32:41PM +0800, sean.wang@mediatek.com wrote: > > From: Sean Wang > > > > The power device is responsible for externally down or up the power > > of the remote MediaTek SoC through the tiny circuit BBPU inside PMIC RTC. > > > > Though it's a part of RTC device, it would be better to be a standalone > > driver than to be a part of existent RTC driver so as to let us make > > concentration on works about power-controlling topic and to obtain > > improvements while the subsystem power/reset constantly growing. > > I don't understand the above sentence. (I'm fine with adding the > driver) Which I was actually meaning is that taking the poweroff driver as the standalone one and placing it under driver/reset/power seems can simply get a help from its subsystem either for function extension or bugfix in the future. I thought that way is better than just an embedded one somewhere in rtc driver or other drivers. > > Currently, the most basic functionality supported is to just power off > > the system by writing to a special bit field in BBPU register after the > > system has reached pm_poweroff. > > > > Signed-off-by: Sean Wang > > --- > > drivers/power/reset/Kconfig | 10 ++++ > > drivers/power/reset/Makefile | 1 + > > drivers/power/reset/mt6323-poweroff.c | 97 +++++++++++++++++++++++++++++++++++ > > include/linux/mfd/mt6397/rtc.h | 1 + > > 4 files changed, 109 insertions(+) > > create mode 100644 drivers/power/reset/mt6323-poweroff.c > > > > diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig > > index df58fc8..7b49d71 100644 > > --- a/drivers/power/reset/Kconfig > > +++ b/drivers/power/reset/Kconfig > > @@ -128,6 +128,16 @@ config POWER_RESET_LTC2952 > > This driver supports an external powerdown trigger and board power > > down via the LTC2952. Bindings are made in the device tree. > > > > +config POWER_RESET_MT6323 > > + bool "MediaTek MT6323 power-off driver" > > + depends on MFD_MT6397 > > + help > > + The power-off driver is responsible for externally shutdown down > > + the power of a remote MediaTek SoC MT6323 is connected to through > > + controlling a tiny circuit BBPU inside MT6323 RTC. > > + > > + Say Y if you have a board where MT6323 could be found. > > + > > config POWER_RESET_QNAP > > bool "QNAP power-off driver" > > depends on OF_GPIO && PLAT_ORION > > diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile > > index 7778c74..8836172 100644 > > --- a/drivers/power/reset/Makefile > > +++ b/drivers/power/reset/Makefile > > @@ -11,6 +11,7 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o > > obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o > > obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o > > obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o > > +obj-$(CONFIG_POWER_RESET_MT6323) += mt6323-poweroff.o > > obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o > > obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o > > obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o > > diff --git a/drivers/power/reset/mt6323-poweroff.c b/drivers/power/reset/mt6323-poweroff.c > > new file mode 100644 > > index 0000000..c195766 > > --- /dev/null > > +++ b/drivers/power/reset/mt6323-poweroff.c > > @@ -0,0 +1,97 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* > > + * Power off through MediaTek PMIC > > + * > > + * Copyright (C) 2018 MediaTek Inc. > > + * > > + * Author: Sean Wang > > + * > > + */ > > + > > +#include > > +#include > > +#include > > Not needed Will be removed. > > > +#include > > +#include > > +#include > > + > > +struct mt6323_pwrc { > > + struct device *dev; > > + struct regmap *regmap; > > + u32 base; > > +}; > > + > > +static struct mt6323_pwrc *mt_pwrc; > > + > > +static void mt6323_do_pwroff(void) > > +{ > > + struct mt6323_pwrc *pwrc = mt_pwrc; > > + unsigned int val; > > + int ret; > > + > > + regmap_write(pwrc->regmap, pwrc->base + RTC_BBPU, RTC_BBPU_KEY); > > + regmap_write(pwrc->regmap, pwrc->base + RTC_WRTGR, 1); > > + > > + ret = regmap_read_poll_timeout(pwrc->regmap, > > + pwrc->base + RTC_BBPU, val, > > + !(val & RTC_BBPU_CBUSY), > > + MTK_RTC_POLL_DELAY_US, > > + MTK_RTC_POLL_TIMEOUT); > > + if (ret) > > + dev_err(pwrc->dev, "failed to write BBPU: %d\n", ret); > > + > > + /* Wait some time until system down, otherwise, notice with a warn */ > > + mdelay(1000); > > + > > + WARN_ONCE(1, "Unable to power off system\n"); > > +} > > + > > +static int mt6323_pwrc_probe(struct platform_device *pdev) > > +{ > > + struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent); > > + struct mt6323_pwrc *pwrc; > > + struct resource *res; > > + > > + pwrc = devm_kzalloc(&pdev->dev, sizeof(*pwrc), GFP_KERNEL); > > + if (!pwrc) > > + return -ENOMEM; > > + > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > > + pwrc->base = res->start; > > + pwrc->regmap = mt6397_chip->regmap; > > + pwrc->dev = &pdev->dev; > > + mt_pwrc = pwrc; > > + > > + pm_power_off = &mt6323_do_pwroff; > > + > > + return 0; > > +} > > + > > +static int mt6323_pwrc_remove(struct platform_device *pdev) > > +{ > > + if (pm_power_off == &mt6323_do_pwroff) > > + pm_power_off = NULL; > > + > > + return 0; > > +} > > + > > +static const struct of_device_id mt6323_pwrc_dt_match[] = { > > + { .compatible = "mediatek,mt6323-pwrc" }, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(of, mt6323_pwrc_dt_match); > > Don't forget to remove the DT table when you respin the series for > the requested binding changes. > Thanks. This table will be removed in the next version. > > +static struct platform_driver mt6323_pwrc_driver = { > > + .probe = mt6323_pwrc_probe, > > + .remove = mt6323_pwrc_remove, > > + .driver = { > > + .name = "mt6323-pwrc", > > + .of_match_table = mt6323_pwrc_dt_match, > > + }, > > +}; > > + > > +module_platform_driver(mt6323_pwrc_driver); > > + > > +MODULE_DESCRIPTION("Poweroff driver for MT6323 PMIC"); > > +MODULE_AUTHOR("Sean Wang "); > > +MODULE_LICENSE("GPL v2"); > > diff --git a/include/linux/mfd/mt6397/rtc.h b/include/linux/mfd/mt6397/rtc.h > > index 480977c..ac932c9 100644 > > --- a/include/linux/mfd/mt6397/rtc.h > > +++ b/include/linux/mfd/mt6397/rtc.h > > @@ -16,6 +16,7 @@ > > > > #define RTC_BBPU 0x0000 > > #define RTC_BBPU_CBUSY BIT(6) > > +#define RTC_BBPU_KEY (0x43 << 8) > > > > #define RTC_WRTGR 0x003c > > The driver looks fine otherwise. > Thanks. > -- Sebastian > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek