From patchwork Sun Mar 15 13:43:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aisheng Dong X-Patchwork-Id: 11439063 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0096C1668 for ; Sun, 15 Mar 2020 13:50:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DF3F920663 for ; Sun, 15 Mar 2020 13:50:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727779AbgCONux (ORCPT ); Sun, 15 Mar 2020 09:50:53 -0400 Received: from inva021.nxp.com ([92.121.34.21]:57578 "EHLO inva021.nxp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727498AbgCONux (ORCPT ); Sun, 15 Mar 2020 09:50:53 -0400 Received: from inva021.nxp.com (localhost [127.0.0.1]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id B3D20200257; Sun, 15 Mar 2020 14:50:51 +0100 (CET) Received: from invc005.ap-rdc01.nxp.com (invc005.ap-rdc01.nxp.com [165.114.16.14]) by inva021.eu-rdc02.nxp.com (Postfix) with ESMTP id E50B120059B; Sun, 15 Mar 2020 14:50:46 +0100 (CET) Received: from localhost.localdomain (shlinux2.ap.freescale.net [10.192.224.44]) by invc005.ap-rdc01.nxp.com (Postfix) with ESMTP id 33471402AE; Sun, 15 Mar 2020 21:50:40 +0800 (SGT) From: Dong Aisheng To: linux-clk@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, sboyd@kernel.org, mturquette@baylibre.com, shawnguo@kernel.org, fabio.estevam@nxp.com, linux-imx@nxp.com, kernel@pengutronix.de, Dong Aisheng Subject: [PATCH V6 11/12] clk: imx: lpcg: add suspend/resume support Date: Sun, 15 Mar 2020 21:43:55 +0800 Message-Id: <1584279836-29825-12-git-send-email-aisheng.dong@nxp.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1584279836-29825-1-git-send-email-aisheng.dong@nxp.com> References: <1584279836-29825-1-git-send-email-aisheng.dong@nxp.com> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org LPCG clock state may be lost when it's power domain is completely off during system suspend/resume and we need save and restore the state properly. Signed-off-by: Dong Aisheng Reviewed-by: Stephen Boyd --- ChangeLog: v5: * make suspend/resume function static * improve code comments v4: no changes v3: new patch --- drivers/clk/imx/clk-imx8qxp-lpcg.c | 1 + drivers/clk/imx/clk-lpcg-scu.c | 37 ++++++++++++++++++++++++++++++ drivers/clk/imx/clk-scu.h | 1 + 3 files changed, 39 insertions(+) diff --git a/drivers/clk/imx/clk-imx8qxp-lpcg.c b/drivers/clk/imx/clk-imx8qxp-lpcg.c index 3385de76f6c7..4d4a3a65bcec 100644 --- a/drivers/clk/imx/clk-imx8qxp-lpcg.c +++ b/drivers/clk/imx/clk-imx8qxp-lpcg.c @@ -364,6 +364,7 @@ static struct platform_driver imx8qxp_lpcg_clk_driver = { .driver = { .name = "imx8qxp-lpcg-clk", .of_match_table = imx8qxp_lpcg_match, + .pm = &imx_clk_lpcg_scu_pm_ops, .suppress_bind_attrs = true, }, .probe = imx8qxp_lpcg_clk_probe, diff --git a/drivers/clk/imx/clk-lpcg-scu.c b/drivers/clk/imx/clk-lpcg-scu.c index 2242e5047a0e..5bd8af371059 100644 --- a/drivers/clk/imx/clk-lpcg-scu.c +++ b/drivers/clk/imx/clk-lpcg-scu.c @@ -33,6 +33,9 @@ struct clk_lpcg_scu { void __iomem *reg; u8 bit_idx; bool hw_gate; + + /* for state save&restore */ + u32 state; }; #define to_clk_lpcg_scu(_hw) container_of(_hw, struct clk_lpcg_scu, hw) @@ -112,6 +115,9 @@ struct clk_hw *__imx_clk_lpcg_scu(struct device *dev, const char *name, hw = ERR_PTR(ret); } + if (dev) + dev_set_drvdata(dev, clk); + return hw; } @@ -122,3 +128,34 @@ void imx_clk_lpcg_scu_unregister(struct clk_hw *hw) clk_hw_unregister(&clk->hw); kfree(clk); } + +static int __maybe_unused imx_clk_lpcg_scu_suspend(struct device *dev) +{ + struct clk_lpcg_scu *clk = dev_get_drvdata(dev); + + clk->state = readl_relaxed(clk->reg); + dev_dbg(dev, "save lpcg state 0x%x\n", clk->state); + + return 0; +} + +static int __maybe_unused imx_clk_lpcg_scu_resume(struct device *dev) +{ + struct clk_lpcg_scu *clk = dev_get_drvdata(dev); + + /* + * FIXME: Sometimes writes don't work unless the CPU issues + * them twice + */ + + writel(clk->state, clk->reg); + writel(clk->state, clk->reg); + dev_dbg(dev, "restore lpcg state 0x%x\n", clk->state); + + return 0; +} + +const struct dev_pm_ops imx_clk_lpcg_scu_pm_ops = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(imx_clk_lpcg_scu_suspend, + imx_clk_lpcg_scu_resume) +}; diff --git a/drivers/clk/imx/clk-scu.h b/drivers/clk/imx/clk-scu.h index 6b29713a71d2..b1dfdaf0734e 100644 --- a/drivers/clk/imx/clk-scu.h +++ b/drivers/clk/imx/clk-scu.h @@ -11,6 +11,7 @@ #include extern struct list_head imx_scu_clks[]; +extern const struct dev_pm_ops imx_clk_lpcg_scu_pm_ops; int imx_clk_scu_init(struct device_node *np); struct clk_hw *imx_scu_of_clk_src_get(struct of_phandle_args *clkspec,