Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752240AbdLHRPf (ORCPT ); Fri, 8 Dec 2017 12:15:35 -0500 Received: from mail.free-electrons.com ([62.4.15.54]:48758 "EHLO mail.free-electrons.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750910AbdLHRPe (ORCPT ); Fri, 8 Dec 2017 12:15:34 -0500 Date: Fri, 8 Dec 2017 18:15:22 +0100 From: Alexandre Belloni To: Sebastian Reichel Cc: Ralf Baechle , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH v2 08/13] power: reset: Add a driver for the Microsemi Ocelot reset Message-ID: <20171208171522.GC15660@piout.net> References: <20171208154618.20105-1-alexandre.belloni@free-electrons.com> <20171208154618.20105-9-alexandre.belloni@free-electrons.com> <20171208170755.n6eqgn2jkjh4rbo5@earth> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171208170755.n6eqgn2jkjh4rbo5@earth> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5454 Lines: 160 On 08/12/2017 at 18:07:55 +0100, Sebastian Reichel wrote: > Hi, > > On Fri, Dec 08, 2017 at 04:46:13PM +0100, Alexandre Belloni wrote: > > The Microsemi Ocelot SoC has a register allowing to reset the MIPS core. > > Unfortunately, the syscon-reboot driver can't be used directly (but almost) > > as the reset control may be disabled using another register. > > > > Cc: Sebastian Reichel > > Cc: linux-pm@vger.kernel.org > > Signed-off-by: Alexandre Belloni > > Is it safe to apply this and the DT binding patch (once it has Rob's > Ack-by) via the power-supply tree? > Absolutely, and I think this is the best plan. > Reviewed-by: Sebastian Reichel > > -- Sebastian > > > drivers/power/reset/Kconfig | 7 ++++ > > drivers/power/reset/Makefile | 1 + > > drivers/power/reset/ocelot-reset.c | 86 ++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 94 insertions(+) > > create mode 100644 drivers/power/reset/ocelot-reset.c > > > > diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig > > index ca0de1a78e85..2372f8e1040d 100644 > > --- a/drivers/power/reset/Kconfig > > +++ b/drivers/power/reset/Kconfig > > @@ -113,6 +113,13 @@ config POWER_RESET_MSM > > help > > Power off and restart support for Qualcomm boards. > > > > +config POWER_RESET_OCELOT_RESET > > + bool "Microsemi Ocelot reset driver" > > + depends on MSCC_OCELOT || COMPILE_TEST > > + select MFD_SYSCON > > + help > > + This driver supports restart for Microsemi Ocelot SoC. > > + > > config POWER_RESET_PIIX4_POWEROFF > > tristate "Intel PIIX4 power-off driver" > > depends on PCI > > diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile > > index aeb65edb17b7..df9d92291c67 100644 > > --- a/drivers/power/reset/Makefile > > +++ b/drivers/power/reset/Makefile > > @@ -12,6 +12,7 @@ obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o > > obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o > > obj-$(CONFIG_POWER_RESET_IMX) += imx-snvs-poweroff.o > > obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o > > +obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o > > obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o > > obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o > > obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o > > diff --git a/drivers/power/reset/ocelot-reset.c b/drivers/power/reset/ocelot-reset.c > > new file mode 100644 > > index 000000000000..1fb14bf17191 > > --- /dev/null > > +++ b/drivers/power/reset/ocelot-reset.c > > @@ -0,0 +1,86 @@ > > +// SPDX-License-Identifier: (GPL-2.0 OR MIT) > > +/* > > + * Microsemi MIPS SoC reset driver > > + * > > + * License: Dual MIT/GPL > > + * Copyright (c) 2017 Microsemi Corporation > > + */ > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +struct ocelot_reset_context { > > + struct regmap *chip_regs; > > + struct regmap *cpu_ctrl; > > + struct notifier_block restart_handler; > > +}; > > + > > +#define ICPU_CFG_CPU_SYSTEM_CTRL_RESET 0x20 > > +#define CORE_RST_PROTECT BIT(2) > > + > > +#define CHIP_REGS_SOFT_RST 0x8 > > +#define SOFT_CHIP_RST BIT(0) > > + > > +static int ocelot_restart_handle(struct notifier_block *this, > > + unsigned long mode, void *cmd) > > +{ > > + struct ocelot_reset_context *ctx = container_of(this, struct > > + ocelot_reset_context, > > + restart_handler); > > + > > + /* Make sure the core is not protected from reset */ > > + regmap_update_bits(ctx->cpu_ctrl, ICPU_CFG_CPU_SYSTEM_CTRL_RESET, > > + CORE_RST_PROTECT, 0); > > + > > + regmap_write(ctx->chip_regs, CHIP_REGS_SOFT_RST, SOFT_CHIP_RST); > > + > > + pr_emerg("Unable to restart system\n"); > > + return NOTIFY_DONE; > > +} > > + > > +static int ocelot_reset_probe(struct platform_device *pdev) > > +{ > > + struct ocelot_reset_context *ctx; > > + struct device *dev = &pdev->dev; > > + int err; > > + > > + ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); > > + if (!ctx) > > + return -ENOMEM; > > + > > + ctx->chip_regs = syscon_node_to_regmap(of_get_parent(dev->of_node)); > > + if (IS_ERR(ctx->chip_regs)) > > + return PTR_ERR(ctx->chip_regs); > > + > > + ctx->cpu_ctrl = syscon_regmap_lookup_by_compatible("mscc,ocelot-cpu-syscon"); > > + if (IS_ERR(ctx->cpu_ctrl)) > > + return PTR_ERR(ctx->cpu_ctrl); > > + > > + ctx->restart_handler.notifier_call = ocelot_restart_handle; > > + ctx->restart_handler.priority = 192; > > + err = register_restart_handler(&ctx->restart_handler); > > + if (err) > > + dev_err(dev, "can't register restart notifier (err=%d)\n", err); > > + > > + return err; > > +} > > + > > +static const struct of_device_id ocelot_reset_of_match[] = { > > + { .compatible = "mscc,ocelot-chip-reset" }, > > + {} > > +}; > > + > > +static struct platform_driver ocelot_reset_driver = { > > + .probe = ocelot_reset_probe, > > + .driver = { > > + .name = "ocelot-chip-reset", > > + .of_match_table = ocelot_reset_of_match, > > + }, > > +}; > > +builtin_platform_driver(ocelot_reset_driver); > > -- > > 2.15.1 > > -- Alexandre Belloni, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com