From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andy Shevchenko Subject: Re: [PATCH] pinctrl: intel: save HOSTSW_OWN register over suspend/resume Date: Tue, 2 Apr 2019 14:58:36 +0300 Message-ID: <20190402115836.GL9224@smile.fi.intel.com> References: <20190327172940.GR3622@lahna.fi.intel.com> <20190328091729.GV9224@smile.fi.intel.com> <20190328123444.GX3622@lahna.fi.intel.com> <20190401074953.GQ3622@lahna.fi.intel.com> <20190401122256.GF9224@smile.fi.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Chris Chiu Cc: Mika Westerberg , Daniel Drake , Heikki Krogerus , Linus Walleij , "open list:PIN CONTROL SUBSYSTEM" , Linux Kernel , Linux Upstreaming Team List-Id: linux-gpio@vger.kernel.org On Tue, Apr 02, 2019 at 02:16:19PM +0800, Chris Chiu wrote: > On Mon, Apr 1, 2019 at 8:23 PM Andy Shevchenko > wrote: > > On Mon, Apr 01, 2019 at 06:41:57PM +0800, Chris Chiu wrote: > Thanks for the comment. My first version did mimic the logic of the interrupt > mask restore but it was based on the DMI quirk. It saves HOSTSW_OWN > for each padgroup and restores them all after resume if DMI info matched. > > What really confused me is how to do this specifically for a requested GPIO > pin. So here's my new proposed patch. Please suggests if there's any better > idea. Thanks. > struct intel_community_context { > u32 *intmask; > + u32 *hostown; This is okay. > }; > +#ifdef CONFIG_PM_SLEEP > +static void intel_save_hostown(struct intel_pinctrl *pctrl, unsigned int pin); > +#endif > + No need for this... > /* Disable TX buffer and enable RX (this will be input) */ > __intel_gpio_set_direction(padcfg0, true); > +#ifdef CONFIG_PM_SLEEP > + intel_save_hostown(pctrl, pin); > +#endif ...and for this. Just save all of them at ->suspend() > for (i = 0; i < pctrl->ncommunities; i++) { > struct intel_community *community = &pctrl->communities[i]; > - u32 *intmask; > + u32 *intmask, *hostown; > > intmask = devm_kcalloc(pctrl->dev, community->ngpps, > sizeof(*intmask), GFP_KERNEL); > @@ -1292,6 +1299,13 @@ static int intel_pinctrl_pm_init(struct > intel_pinctrl *pctrl) > return -ENOMEM; > > communities[i].intmask = intmask; > + > + hostown = devm_kcalloc(pctrl->dev, community->ngpps, > + sizeof(*hostown), GFP_KERNEL); > + if (!hostown) > + return -ENOMEM; > + > + communities[i].hostown= hostown; This is good. > } > +static void intel_save_hostown(struct intel_pinctrl *pctrl, unsigned int pin) > +{ > + const struct intel_community *community; > + const struct intel_padgroup *padgrp; > + int i; > + > + community = intel_get_community(pctrl, pin); > + if (!community) > + return; > + if (!community->hostown_offset) > + return; > + > + padgrp = intel_community_get_padgroup(community, pin); > + if (!padgrp) > + return; > + > + for (i = 0; i < pctrl->ncommunities; i++) { > + const struct intel_community *comm = &pctrl->communities[i]; > + int j; > + > + for (j = 0; j < comm->ngpps; j++) { > + const struct intel_padgroup *pgrp = &comm->gpps[j]; > + > + if (padgrp == pgrp) { > + struct intel_community_context *communities; > + void __iomem *base; > + > + communities = pctrl->context.communities; > + base = community->regs + > community->hostown_offset; > + communities[i].hostown[j] = readl(base + j * 4); > + break; > + } > + } > + } > + return; Useless. > +} This is too complicated. Just add base = community->regs + community->hostown_offset; for (gpp = 0; gpp < community->ngpps; gpp++) communities[i].hostown[gpp] = readl(base + gpp * 4); into ->suspend() loop. > + base = community->regs + community->hostown_offset; > + for (gpp = 0; gpp < community->ngpps; gpp++) { > + if (communities[i].hostown[gpp] && > + communities[i].hostown[gpp] != readl(base > + gpp * 4)) { > + writel(communities[i].hostown[gpp], > base + gpp * 4); > + dev_warn(dev, "hostown changed after resume\n"); > + dev_dbg(dev, "restored hostown %d/%u > %#08x\n", i, gpp, > + readl(base + gpp * 4)); > + } > + } Instead you may need to loop over each pin in the part of the group related to one 32-bit HOSTSW_OWN register (i.e. 8, see PADOWN_*() macros in the driver), check if it's requested and break a loop. If loop index is off-by-one a limit, nothing to do, otherwise restore hostown register. More pedantic approach is to collect the mask inside the loop and apply it. The check function name is gpiochip_is_requested(). (One of Intel's drivers which is using that at ->resume() is drivers/gpio/gpio-lynxpoint.c) P.S. I prefer pedantic approach. The simplification one is showed in order to give you an idea. -- With Best Regards, Andy Shevchenko