From patchwork Wed Feb 24 06:11:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?Smlhbmp1biBXYW5nICjnjovlu7rlhpsp?= X-Patchwork-Id: 1443718 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pci-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Dllws40vPz9sVV for ; Wed, 24 Feb 2021 17:13:49 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234126AbhBXGNf (ORCPT ); Wed, 24 Feb 2021 01:13:35 -0500 Received: from mailgw02.mediatek.com ([210.61.82.184]:34615 "EHLO mailgw02.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S230234AbhBXGNU (ORCPT ); Wed, 24 Feb 2021 01:13:20 -0500 X-UUID: 0070d911e420495ba96d4b23f3a67225-20210224 X-UUID: 0070d911e420495ba96d4b23f3a67225-20210224 Received: from mtkcas11.mediatek.inc [(172.21.101.40)] by mailgw02.mediatek.com (envelope-from ) (Cellopoint E-mail Firewall v4.1.14 Build 0819 with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1529753573; Wed, 24 Feb 2021 14:12:35 +0800 Received: from mtkcas07.mediatek.inc (172.21.101.84) by mtkmbs05n2.mediatek.inc (172.21.101.140) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 24 Feb 2021 14:12:34 +0800 Received: from localhost.localdomain (10.17.3.153) by mtkcas07.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 24 Feb 2021 14:12:33 +0800 From: Jianjun Wang To: Bjorn Helgaas , Rob Herring , , Lorenzo Pieralisi , Ryder Lee CC: Philipp Zabel , Matthias Brugger , , , , , , Sj Huang , Jianjun Wang , , , , , , , Subject: [v8,6/7] PCI: mediatek-gen3: Add system PM support Date: Wed, 24 Feb 2021 14:11:31 +0800 Message-ID: <20210224061132.26526-7-jianjun.wang@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20210224061132.26526-1-jianjun.wang@mediatek.com> References: <20210224061132.26526-1-jianjun.wang@mediatek.com> MIME-Version: 1.0 X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Add suspend_noirq and resume_noirq callback functions to implement PM system suspend hooks for MediaTek Gen3 PCIe controller. When system suspend, trigger the PCIe link to L2 state and pull down the PERST# pin, gating the clocks of MAC layer and power off the physical layer for the sake of power saving. When system resum, the PCIe link should be re-established and the related control register values should be restored. Signed-off-by: Jianjun Wang Acked-by: Ryder Lee --- drivers/pci/controller/pcie-mediatek-gen3.c | 84 +++++++++++++++++++++ 1 file changed, 84 insertions(+) diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c index fde9de591888..fd13540d37fe 100644 --- a/drivers/pci/controller/pcie-mediatek-gen3.c +++ b/drivers/pci/controller/pcie-mediatek-gen3.c @@ -45,6 +45,9 @@ #define PCIE_PE_RSTB BIT(3) #define PCIE_LTSSM_STATUS_REG 0x150 +#define PCIE_LTSSM_STATE_MASK GENMASK(28, 24) +#define PCIE_LTSSM_STATE(val) ((val & PCIE_LTSSM_STATE_MASK) >> 24) +#define PCIE_LTSSM_STATE_L2_IDLE 0x14 #define PCIE_LINK_STATUS_REG 0x154 #define PCIE_PORT_LINKUP BIT(8) @@ -73,6 +76,9 @@ #define PCIE_MSI_SET_ADDR_HI_BASE 0xc80 #define PCIE_MSI_SET_ADDR_HI_OFFSET 0x04 +#define PCIE_ICMD_PM_REG 0x198 +#define PCIE_TURN_OFF_LINK BIT(4) + #define PCIE_TRANS_TABLE_BASE_REG 0x800 #define PCIE_ATR_SRC_ADDR_MSB_OFFSET 0x4 #define PCIE_ATR_TRSL_ADDR_LSB_OFFSET 0x8 @@ -892,6 +898,83 @@ static int mtk_pcie_remove(struct platform_device *pdev) return 0; } +static int __maybe_unused mtk_pcie_turn_off_link(struct mtk_pcie_port *port) +{ + u32 val; + + val = readl_relaxed(port->base + PCIE_ICMD_PM_REG); + val |= PCIE_TURN_OFF_LINK; + writel_relaxed(val, port->base + PCIE_ICMD_PM_REG); + + /* Check the link is L2 */ + return readl_poll_timeout(port->base + PCIE_LTSSM_STATUS_REG, val, + (PCIE_LTSSM_STATE(val) == + PCIE_LTSSM_STATE_L2_IDLE), 20, + 50 * USEC_PER_MSEC); +} + +static int __maybe_unused mtk_pcie_suspend_noirq(struct device *dev) +{ + struct mtk_pcie_port *port = dev_get_drvdata(dev); + int err; + u32 val; + + /* Trigger link to L2 state */ + err = mtk_pcie_turn_off_link(port); + if (err) { + dev_err(port->dev, "can not enter L2 state\n"); + return err; + } + + /* Pull down the PERST# pin */ + val = readl_relaxed(port->base + PCIE_RST_CTRL_REG); + val |= PCIE_PE_RSTB; + writel_relaxed(val, port->base + PCIE_RST_CTRL_REG); + + dev_dbg(port->dev, "enter L2 state success"); + + clk_bulk_disable_unprepare(port->num_clks, port->clks); + + reset_control_assert(port->mac_reset); + + phy_power_off(port->phy); + reset_control_assert(port->phy_reset); + + return 0; +} + +static int __maybe_unused mtk_pcie_resume_noirq(struct device *dev) +{ + struct mtk_pcie_port *port = dev_get_drvdata(dev); + int err; + + reset_control_deassert(port->phy_reset); + phy_power_on(port->phy); + + reset_control_deassert(port->mac_reset); + + err = clk_bulk_prepare_enable(port->num_clks, port->clks); + if (err) { + dev_dbg(dev, "failed to enable PCIe clocks\n"); + return err; + } + + err = mtk_pcie_startup_port(port); + if (err) { + dev_err(port->dev, "resume failed\n"); + return err; + } + + dev_dbg(port->dev, "resume done\n"); + + return 0; +} + +static const struct dev_pm_ops mtk_pcie_pm_ops = { + SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(mtk_pcie_suspend_noirq, + mtk_pcie_resume_noirq) +}; + static const struct of_device_id mtk_pcie_of_match[] = { { .compatible = "mediatek,mt8192-pcie" }, {}, @@ -903,6 +986,7 @@ static struct platform_driver mtk_pcie_driver = { .driver = { .name = "mtk-pcie", .of_match_table = mtk_pcie_of_match, + .pm = &mtk_pcie_pm_ops, }, };