From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756268AbbCMALQ (ORCPT ); Thu, 12 Mar 2015 20:11:16 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:64824 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753519AbbCMALG (ORCPT ); Thu, 12 Mar 2015 20:11:06 -0400 X-AuditID: cbfee690-f79ab6d0000046f7-c4-55022b16ae42 Message-id: <55022B16.7070408@samsung.com> Date: Fri, 13 Mar 2015 09:11:02 +0900 From: Chanwoo Choi User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-version: 1.0 To: Maxime Coquelin Cc: u.kleine-koenig@pengutronix.de, afaerber@suse.de, geert@linux-m68k.org, Rob Herring , Philipp Zabel , Linus Walleij , Arnd Bergmann , stefan@agner.ch, pmeerw@pmeerw.net, pebolle@tiscali.nl, Jonathan Corbet , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Russell King , Daniel Lezcano , Thomas Gleixner , Greg Kroah-Hartman , Jiri Slaby , Andrew Morton , "David S. Miller" , Mauro Carvalho Chehab , Joe Perches , Antti Palosaari , Tejun Heo , Will Deacon , Nikolay Borisov , Rusty Russell , Kees Cook , Michal Marek , linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-gpio@vger.kernel.org, linux-serial@vger.kernel.org, linux-arch@vger.kernel.org, linux-api@vger.kernel.org Subject: Re: [PATCH v3 06/15] drivers: reset: Add STM32 reset driver References: <1426197361-19290-1-git-send-email-maxime.coquelin@st.com> <1426197361-19290-7-git-send-email-maxime.coquelin@st.com> In-reply-to: <1426197361-19290-7-git-send-email-maxime.coquelin@st.com> Content-type: text/plain; charset=ISO-8859-1 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA02SbUhTYRTHe+597r1zZd1M7WkilRGJvZimdaL3D9ENCoIwog/VsotWamPX YlEfpFmapWmW1ZyWWix1Jk3pZZjOzcpIp7GyF3Namr0XYr41rbZG4LffOZz///wPHBnt52IU sn1JyaI6SZkQwsqx0T9KvTBwPhWzeLRpJWhNEugrjSyMnXvIQY8lDcGQ9gcLhf3BoG9JxXCl wc7A2a9FDPS+vk+BtqSSBfvnUgT5nd0Y+l1mBppOJ8L5UQMFVUPpLKSbBzCYutsYKDp5DUPV lVEEDrOehaaSTA7aHb5w/cVTCsp7NVA4VsFAam0rBZ2DOg46nI0Ysi9WYCh+3USDy+xOdOJ+ Awev8lrdRjfTOKgyXaDhl+EBgvacXASf+hrx2lChZMhJC8ZCIxJStWdYwfXrHBLyU55iwZGV SQnVpa8o4Z6ugxNKDT9ZwTZQhAVT2SlWeNNWwwrf7XZOaLzkwoLVlo6EugIjtyVoh3zlXjFh 32FRHb56tzze2ZXBqd7M09izfrMp6MKsDCSTET6K1HVOzkA+bgwkrc5KNgPJZX78dUQsI83U /xlry0xvvxiRavN75C2+IDJ4R8t51L58GGm8XE17GPNzyduubsrDrLtf9/El6+EAfhspvfgM e+enkuFcJ/Ys8OfDybBW4/GkeZucvBj+8087jV9PnpQVc95lWkQe2/X/jHz4DcRSP8Z4mOYX kLoTeayXZ5Iq4zfaIyB8lpzUtxdw3kQ8Gcy1Yu85wcRkob0nzyD1N17ibBSoG5dJN85WN872 KqLLUICoilVJe+LUUYskZaJ0KCluUezBRBNy/+ST373Zd5HTssKKeBkKmeSrGZgQ48coD0tH Eq0o2p0ih1YExB50v3FS8q6IJUsjIToqeknksuVLQ6b7flGMbPXj45TJ4gFRVInqXepDCaJk RZTMR5GCDI6pN6cc+7Cjrf5AWb9te3D+9MijI7bKh7dWt9b6D1r69Bt9gvpDN9fste98EF2+ e05sh3VKUCcbUZH257ZBdbLGf6fiXYXUx2yaHbC/ZWszvU6jKjjt+KFpvqap7up5Pls1Mb55 z6rwvNCc2w3T4tHxM/cy9WsftfSErbk1VNs7qSsES/HKiDBaLSn/ApcZGDaOAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrGJsWRmVeSWpSXmKPExsVy+t9jAV0xbaZQg8l7DCyaNxVbzFm/hs3i 76Rj7BZPDrQzWnxvfs9mMe+zrMWc8y0sFvOPnGO16H+zkNXi2a29TBbNi9ezWZx7tZLRYvb9 xywWn3/vYrU4051rMeXPciaLzd872Cw6dn1lsdj0+BqrxcK2JSwWm+f/YbS4vGsOm8WZxb3s Frcv81osvX6RyWL1swqLeX/Xslq07LvAZHH/2yx2i7v3TrBYTJi+lsVi0a0zzBa/dwFd1Lr3 CLvFzWkXgAata2e32LxpKrPFr+VHGS1uT5zMaPHy4wkWBw2Pxd/vMXusmbeG0aOluYfN4/ev SYwesxsusnhc7utl8tiy8iaTx85Zd9k9Vi7/wuZx+OtCFo9NqzrZPO5c28Pm8e7cOXaPEzN+ s3gcOtzB6LF/7hr2AOmoBkabjNTElNQihdS85PyUzLx0WyXv4HjneFMzA0NdQ0sLcyWFvMTc VFslF58AXbfMHGD4KimUJeaUAoUCEouLlfTtME0IDXHTtYBpjND1DQmC6zEyQAMJaxgz7j3o Yi+4o15xru8fWwPjVIUuRg4OCQETiUPn5bsYOYFMMYkL99azdTFycQgJLGKU2LLrKSOE85pR 4tv2ZnaQKl4BLYkTM7cwg9gsAqoSDx88ZgKx2YDi+1/cYAOxRQXCJFZOv8ICUS8o8WPyPRaQ ZSIC+hI/mitAZjILHOaSuP7jP1ivsICrxOlVi9ghljUzSpw8NwdsEKeAu8SBg39ZQWxmAR2J /a3T2CBseYnNa94yT2AUmIVkxywkZbOQlC1gZF7FKJpakFxQnJSea6RXnJhbXJqXrpecn7uJ EZyGn0nvYFzVYHGIUYCDUYmH98J3hlAh1sSy4srcQ4wSHMxKIrz/TzKGCvGmJFZWpRblxxeV 5qQWH2I0BQbBRGYp0eR8YI7IK4k3NDYxM7I0Mje0MDI2VxLnVbJvCxESSE8sSc1OTS1ILYLp Y+LglGpg5Hr+lff5tcxPC2ZL7Xs6Oa7rveCEuFUHOpq+V0kxXJp9Kc39O5PzsThX36R4C4vT /0tkFX5svJwvKqCx9Wd/oemj4FfmETZLRO4GWuTUNn2uztEwS2bkD03Oqt0+We1HEpe9CX9U Qt05o5Oex6wurGsUqj4onS+t8/eG97SljFbVMhdz2J8qsRRnJBpqMRcVJwIAku+6EdkDAAA= DLP-Filter: Pass X-MTR: 20000000000000000@CPGS X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Maxime, On 03/13/2015 06:55 AM, Maxime Coquelin wrote: > From: Maxime Coquelin > > The STM32 MCUs family IP can be reset by accessing some shared registers. > > The specificity is that some reset lines are used by the timers. > At timer initialization time, the timer has to be reset, that's why > we cannot use a regular driver. > > Signed-off-by: Maxime Coquelin > --- > drivers/reset/Makefile | 1 + > drivers/reset/reset-stm32.c | 125 ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 126 insertions(+) > create mode 100644 drivers/reset/reset-stm32.c > > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile > index 157d421..aed12d1 100644 > --- a/drivers/reset/Makefile > +++ b/drivers/reset/Makefile > @@ -1,5 +1,6 @@ > obj-$(CONFIG_RESET_CONTROLLER) += core.o > obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o > obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o > +obj-$(CONFIG_ARCH_STM32) += reset-stm32.o > obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o > obj-$(CONFIG_ARCH_STI) += sti/ > diff --git a/drivers/reset/reset-stm32.c b/drivers/reset/reset-stm32.c > new file mode 100644 > index 0000000..0d389b1 > --- /dev/null > +++ b/drivers/reset/reset-stm32.c > @@ -0,0 +1,125 @@ > +/* > + * Copyright (C) Maxime Coquelin 2015 > + * Author: Maxime Coquelin > + * License terms: GNU General Public License (GPL), version 2 > + * > + * Heavily based on sunxi driver from Maxime Ripard. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +struct stm32_reset_data { > + spinlock_t lock; > + void __iomem *membase; > + struct reset_controller_dev rcdev; > +}; > + > +static int stm32_reset_assert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct stm32_reset_data *data = container_of(rcdev, > + struct stm32_reset_data, > + rcdev); > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + unsigned long flags; > + u32 reg; > + > + spin_lock_irqsave(&data->lock, flags); > + > + reg = readl_relaxed(data->membase + (bank * 4)); > + writel_relaxed(reg | BIT(offset), data->membase + (bank * 4)); > + > + spin_unlock_irqrestore(&data->lock, flags); > + > + return 0; > +} > + > +static int stm32_reset_deassert(struct reset_controller_dev *rcdev, > + unsigned long id) > +{ > + struct stm32_reset_data *data = container_of(rcdev, > + struct stm32_reset_data, > + rcdev); > + int bank = id / BITS_PER_LONG; > + int offset = id % BITS_PER_LONG; > + unsigned long flags; > + u32 reg; > + > + spin_lock_irqsave(&data->lock, flags); > + > + reg = readl_relaxed(data->membase + (bank * 4)); > + writel_relaxed(reg & ~BIT(offset), data->membase + (bank * 4)); > + > + spin_unlock_irqrestore(&data->lock, flags); > + > + return 0; > +} > + > +static struct reset_control_ops stm32_reset_ops = { > + .assert = stm32_reset_assert, > + .deassert = stm32_reset_deassert, > +}; > + > +static const struct of_device_id stm32_reset_dt_ids[] = { > + { .compatible = "st,stm32-rcc", }, > + { /* sentinel */ }, > +}; > +MODULE_DEVICE_TABLE(of, sstm32_reset_dt_ids); > + > +static int stm32_reset_probe(struct platform_device *pdev) > +{ > + struct stm32_reset_data *data; > + struct resource *res; > + > + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + data->membase = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(data->membase)) > + return PTR_ERR(data->membase); > + > + spin_lock_init(&data->lock); > + > + data->rcdev.owner = THIS_MODULE; > + data->rcdev.nr_resets = resource_size(res) * 8; > + data->rcdev.ops = &stm32_reset_ops; > + data->rcdev.of_node = pdev->dev.of_node; > + > + return reset_controller_register(&data->rcdev); > +} > + > +static int stm32_reset_remove(struct platform_device *pdev) > +{ > + struct stm32_reset_data *data = platform_get_drvdata(pdev); > + > + reset_controller_unregister(&data->rcdev); > + > + return 0; > +} > + > +static struct platform_driver stm32_reset_driver = { > + .probe = stm32_reset_probe, > + .remove = stm32_reset_remove, > + .driver = { > + .name = "stm32-rcc-reset", > + .of_match_table = stm32_reset_dt_ids, > + }, > +}; > +module_platform_driver(stm32_reset_driver); > + > +MODULE_AUTHOR("Maxime Coquelin "); > +MODULE_DESCRIPTION("STM32 MCUs Reset Controller Driver"); > +MODULE_LICENSE("GPL"); > + > Last blank line is un-necessary. When I applied this patch for test, "new blank line at EOF" happen. Thanks, Chanwoo Choi