From mboxrd@z Thu Jan 1 00:00:00 1970 From: Faiz Abbas Subject: [PATCH v3 4/6] bus: ti-sysc: Add support for software reset Date: Wed, 6 Jun 2018 11:38:24 +0530 Message-ID: <20180606060826.14671-5-faiz_abbas@ti.com> References: <20180606060826.14671-1-faiz_abbas@ti.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <20180606060826.14671-1-faiz_abbas@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: 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 Cc: robh+dt@kernel.org, bcousson@baylibre.com, tony@atomide.com, paul@pwsan.com, t-kristo@ti.com, faiz_abbas@ti.com, mark.rutland@arm.com List-Id: devicetree@vger.kernel.org Add support for the software reset of a target interconnect module using its sysconfig and sysstatus registers. Signed-off-by: Faiz Abbas --- drivers/bus/ti-sysc.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c index 4a2244419b9b..74d716a7bd6e 100644 --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -22,11 +22,14 @@ #include #include #include +#include #include #include +#define MAX_MODULE_SOFTRESET_WAIT 10000 + static const char * const reg_names[] = { "rev", "sysc", "syss", }; enum sysc_clocks { @@ -74,6 +77,11 @@ 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) { @@ -700,6 +708,26 @@ static void sysc_init_revision_quirks(struct sysc *ddata) } } +static int sysc_reset(struct sysc *ddata) +{ + int offset = ddata->offsets[SYSC_SYSCONFIG]; + int val = sysc_read(ddata, offset); + + val |= (0x1 << ddata->cap->regbits->srst_shift); + sysc_write(ddata, offset, val); + + /* Poll on reset status */ + if (ddata->cfg.quirks & SYSC_QUIRK_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); + } + + return 0; +} + /* At this point the module is configured enough to read the revision */ static int sysc_init_module(struct sysc *ddata) { @@ -716,6 +744,18 @@ static int sysc_init_module(struct sysc *ddata) return 0; } + + if (!(ddata->cfg.quirks & SYSC_QUIRK_NO_RESET_ON_INIT) && + !ddata->legacy_mode) { + 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); -- 2.17.0