From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH v5 4/6] bus: ti-sysc: Add support for software reset Date: Tue, 10 Jul 2018 04:42:48 -0700 Message-ID: <20180710114248.GI99251@atomide.com> References: <20180709164841.14182-1-faiz_abbas@ti.com> <20180709164841.14182-5-faiz_abbas@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20180709164841.14182-5-faiz_abbas@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Faiz Abbas Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-clk@vger.kernel.org, robh+dt@kernel.org, bcousson@baylibre.com, paul@pwsan.com, t-kristo@ti.com, mark.rutland@arm.com, sboyd@kernel.org List-Id: devicetree@vger.kernel.org Hi, * Faiz Abbas [180709 16:50]: > Add support for the software reset of a target interconnect > module using its sysconfig and sysstatus registers. ... > --- a/drivers/bus/ti-sysc.c > +++ b/drivers/bus/ti-sysc.c ... > +static int sysc_reset(struct sysc *ddata) > +{ > + int offset = ddata->offsets[SYSC_SYSCONFIG]; > + int val = sysc_read(ddata, offset); Testing with omap4 sysc dts data I noticed we already have modules where there is only rev register and no SYSC_SYSCONFIG. So not using legacy mode. The above offset with -ENODEV value will not work :) I added some more checks and moved them to the reset function. Updated patch below for reference, I've pushed out new branches omap-for-v4.19/ti-sysc-v2 and omap-for-v4.19/dt-mcan-v2. I've also updated my for-next branch. Regards, Tony 8< ----------- >>From tony Mon Sep 17 00:00:00 2001 From: Faiz Abbas Date: Mon, 9 Jul 2018 22:18:39 +0530 Subject: [PATCH] bus: ti-sysc: Add support for software reset Add support for the software reset of a target interconnect module using its sysconfig and sysstatus registers. Signed-off-by: Faiz Abbas [tony@atomide.com: updated to check if sysconfig exists] Signed-off-by: Tony Lindgren --- drivers/bus/ti-sysc.c | 46 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -23,11 +23,14 @@ #include #include #include +#include #include #include +#define MAX_MODULE_SOFTRESET_WAIT 10000 + static const char * const reg_names[] = { "rev", "sysc", "syss", }; enum sysc_clocks { @@ -88,6 +91,11 @@ struct sysc { struct delayed_work idle_work; }; +void sysc_write(struct sysc *ddata, int offset, u32 value) +{ + writel_relaxed(value, ddata->module_va + offset); +} + static u32 sysc_read(struct sysc *ddata, int offset) { if (ddata->cfg.quirks & SYSC_QUIRK_16BIT) { @@ -943,6 +951,36 @@ static void sysc_init_revision_quirks(struct sysc *ddata) } } +static int sysc_reset(struct sysc *ddata) +{ + int offset = ddata->offsets[SYSC_SYSCONFIG]; + int val; + + if (ddata->legacy_mode || offset < 0 || + ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT) + return 0; + + /* + * Currently only support reset status in sysstatus. + * Warn and return error in all other cases + */ + if (!ddata->cfg.syss_mask) { + dev_err(ddata->dev, "No ti,syss-mask. Reset failed\n"); + return -EINVAL; + } + + val = sysc_read(ddata, offset); + val |= (0x1 << ddata->cap->regbits->srst_shift); + sysc_write(ddata, offset, val); + + /* Poll on reset status */ + offset = ddata->offsets[SYSC_SYSSTATUS]; + + return readl_poll_timeout(ddata->module_va + offset, val, + (val & ddata->cfg.syss_mask) == 0x0, + 100, MAX_MODULE_SOFTRESET_WAIT); +} + /* At this point the module is configured enough to read the revision */ static int sysc_init_module(struct sysc *ddata) { @@ -960,6 +998,14 @@ static int sysc_init_module(struct sysc *ddata) return 0; } + error = sysc_reset(ddata); + if (error) { + dev_err(ddata->dev, "Reset failed with %d\n", error); + pm_runtime_put_sync(ddata->dev); + + return error; + } + ddata->revision = sysc_read_revision(ddata); pm_runtime_put_sync(ddata->dev); -- 2.17.1