From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tero Kristo Subject: [PATCHv2 03/11] soc: ti: omap-prm: poll for reset complete during de-assert Date: Wed, 28 Aug 2019 10:19:33 +0300 Message-ID: <20190828071941.32378-4-t-kristo@ti.com> References: <20190828071941.32378-1-t-kristo@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190828071941.32378-1-t-kristo@ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: ssantosh@kernel.org, linux-arm-kernel@lists.infradead.org, linux-omap@vger.kernel.org, robh+dt@kernel.org, p.zabel@pengutronix.de Cc: tony@atomide.com, devicetree@vger.kernel.org List-Id: linux-omap@vger.kernel.org Poll for reset completion status during de-assertion of reset, otherwise the IP in question might be accessed before it has left reset properly. Signed-off-by: Tero Kristo --- drivers/soc/ti/omap_prm.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/drivers/soc/ti/omap_prm.c b/drivers/soc/ti/omap_prm.c index fd5c431f8736..afeb70761b27 100644 --- a/drivers/soc/ti/omap_prm.c +++ b/drivers/soc/ti/omap_prm.c @@ -127,6 +127,7 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, u32 v; int st_bit; bool has_rstst; + int timeout = 0; if (!_is_valid_reset(reset, id)) return -EINVAL; @@ -153,6 +154,25 @@ static int omap_reset_deassert(struct reset_controller_dev *rcdev, v &= ~(1 << id); writel_relaxed(v, reset->prm->base + reset->prm->data->rstctrl); + if (!has_rstst) + return 0; + + /* wait for the status to be set */ + while (1) { + v = readl_relaxed(reset->prm->base + reset->prm->data->rstst); + v &= 1 << st_bit; + if (v) + break; + timeout++; + if (timeout > OMAP_RESET_MAX_WAIT) { + pr_err("%s: timedout waiting for %s:%lu\n", __func__, + dev_name(rcdev->dev), id); + return -EBUSY; + } + + udelay(1); + } + return 0; } -- 2.17.1 -- Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki