From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 771A6C3A5A3 for ; Tue, 27 Aug 2019 14:13:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 49673217F5 for ; Tue, 27 Aug 2019 14:13:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566915210; bh=pl2trC3SUKLOMkiq8cJFVya7N1BiXPCf1NJhGvJLSMw=; h=From:To:Cc:Subject:Date:List-ID:From; b=dLyQmSiHTwzyy/nULtvcTVJxj9se58jmgvfMP5hs2rtkBVkdJDQ9xlS6+DGu29CyW bar/ppKLIHqWxO4sel/SvafO9yGKyDGEcRQILCJipgQeoQ5FkwaKS7ZFjrEZuvs/DH wDmNo7z4DK16mWBdv+MNUiJwFRlafJgxGQtOec8Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730101AbfH0ON3 (ORCPT ); Tue, 27 Aug 2019 10:13:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:39316 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729159AbfH0ON3 (ORCPT ); Tue, 27 Aug 2019 10:13:29 -0400 Received: from localhost.localdomain (cpe-70-114-128-244.austin.res.rr.com [70.114.128.244]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4CB52214DA; Tue, 27 Aug 2019 14:13:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566915208; bh=pl2trC3SUKLOMkiq8cJFVya7N1BiXPCf1NJhGvJLSMw=; h=From:To:Cc:Subject:Date:From; b=NBcLeWKjodp6DLvUNoe/GG4H9KDx7NsTp+DJ7tH/ydWrFedw9eck+AcxxEJbK+nDk uEikpV6cGeBlB14TQPMBjzRXXPL1ki0eVbmOTI9WmOyFlsMkkN/C6O5dfciw4m7/qw vVhaq7mVFhCnlTK277nOfy12FBpandzq+VL1mXY8= From: Dinh Nguyen To: linux-kernel@vger.kernel.org Cc: dinguyen@kernel.org, devicetree@vger.kernel.org, robh@kernel.org, linux@armlinux.org.uk, frowand.list@gmail.com, keescook@chromium.org, anton@enomsg.org, ccross@android.com, tony.luck@intel.com, daniel.thompson@linaro.org, linus.walleij@linaro.org, manivannan.sadhasivam@linaro.org, linux-arm-kernel@lists.infradead.org, p.zabel@pengutronix.de Subject: [PATCHv6] drivers/amba: add reset control to amba bus probe Date: Tue, 27 Aug 2019 09:11:53 -0500 Message-Id: <20190827141153.20254-1-dinguyen@kernel.org> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The primecell controller on some SoCs, i.e. SoCFPGA, is held in reset by default. Until recently, the DMA controller was brought out of reset by the bootloader(i.e. U-Boot). But a recent change in U-Boot, the peripherals that are not used are held in reset and are left to Linux to bring them out of reset. Add a mechanism for getting the reset property and de-assert the primecell module from reset if found. This is a not a hard fail if the reset properti is not present in the device tree node, so the driver will continue to probe. Because there are different variants of the controller that may have multiple reset signals, the code will find all reset(s) specified and de-assert them. Signed-off-by: Dinh Nguyen Reviewed-by: Rob Herring --- v6: remove the need to reset_control_get_count as of_reset_control_array_get_optional_shared is already doing that v5: use of_reset_control_array_get_optional_shared() v4: cleaned up indentation in loop fix up a few checkpatch warnings add Reviewed-by: v3: add a reset_control_put() add error handling v2: move reset control to bus code find all reset properties and de-assert them --- drivers/amba/bus.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 100e798a5c82..f39f075abff9 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -18,6 +18,7 @@ #include #include #include +#include #include @@ -401,6 +402,19 @@ static int amba_device_try_add(struct amba_device *dev, struct resource *parent) ret = amba_get_enable_pclk(dev); if (ret == 0) { u32 pid, cid; + struct reset_control *rstc; + + /* + * Find reset control(s) of the amba bus and de-assert them. + */ + rstc = of_reset_control_array_get_optional_shared(dev->dev.of_node); + if (IS_ERR(rstc)) { + if (PTR_ERR(rstc) != -EPROBE_DEFER) + dev_err(&dev->dev, "Can't get amba reset!\n"); + return PTR_ERR(rstc); + } + reset_control_deassert(rstc); + reset_control_put(rstc); /* * Read pid and cid based on size of resource -- 2.20.0