From patchwork Tue Apr 20 06:17:22 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: 12213377 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=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 3DEB3C43461 for ; Tue, 20 Apr 2021 06:17:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1A98F613C4 for ; Tue, 20 Apr 2021 06:17:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230105AbhDTGSZ (ORCPT ); Tue, 20 Apr 2021 02:18:25 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:53803 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S230134AbhDTGSY (ORCPT ); Tue, 20 Apr 2021 02:18:24 -0400 X-UUID: 926c04b1837d403ba9d3a3d2fdad25a0-20210420 X-UUID: 926c04b1837d403ba9d3a3d2fdad25a0-20210420 Received: from mtkexhb02.mediatek.inc [(172.21.101.103)] by mailgw01.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 1976152000; Tue, 20 Apr 2021 14:17:48 +0800 Received: from mtkcas10.mediatek.inc (172.21.101.39) by mtkmbs05n2.mediatek.inc (172.21.101.140) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Tue, 20 Apr 2021 14:17:47 +0800 Received: from localhost.localdomain (10.17.3.153) by mtkcas10.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 20 Apr 2021 14:17:45 +0800 From: Jianjun Wang To: Bjorn Helgaas , Rob Herring , Marc Zyngier , Lorenzo Pieralisi , Ryder Lee CC: Philipp Zabel , Matthias Brugger , , , , , , Jianjun Wang , , , , , , , , Krzysztof Wilczyski , =?utf-8?q?Pali_Roh=C3=A1r?= Subject: [PATCH v10 6/7] PCI: mediatek-gen3: Add system PM support Date: Tue, 20 Apr 2021 14:17:22 +0800 Message-ID: <20210420061723.989-7-jianjun.wang@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20210420061723.989-1-jianjun.wang@mediatek.com> References: <20210420061723.989-1-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 and resume hooks for the MediaTek Gen3 PCIe controller. When the system suspends, trigger the PCIe link to enter the L2 state and pull down the PERST# pin, gating the clocks of the MAC layer, and then power-off the physical layer to provide power-saving. When the system resumes, 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 | 113 ++++++++++++++++++++ 1 file changed, 113 insertions(+) diff --git a/drivers/pci/controller/pcie-mediatek-gen3.c b/drivers/pci/controller/pcie-mediatek-gen3.c index ee1b51207d11..20165e4a75b2 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 @@ -95,10 +101,12 @@ * struct mtk_msi_set - MSI information for each set * @base: IO mapped register base * @msg_addr: MSI message address + * @saved_irq_state: IRQ enable state saved at suspend time */ struct mtk_msi_set { void __iomem *base; phys_addr_t msg_addr; + u32 saved_irq_state; }; /** @@ -112,6 +120,7 @@ struct mtk_msi_set { * @clks: PCIe clocks * @num_clks: PCIe clocks count for this port * @irq: PCIe controller interrupt number + * @saved_irq_state: IRQ enable state saved at suspend time * @irq_lock: lock protecting IRQ register access * @intx_domain: legacy INTx IRQ domain * @msi_domain: MSI IRQ domain @@ -131,6 +140,7 @@ struct mtk_pcie_port { int num_clks; int irq; + u32 saved_irq_state; raw_spinlock_t irq_lock; struct irq_domain *intx_domain; struct irq_domain *msi_domain; @@ -894,6 +904,108 @@ static int mtk_pcie_remove(struct platform_device *pdev) return 0; } +static void __maybe_unused mtk_pcie_irq_save(struct mtk_pcie_port *port) +{ + int i; + + raw_spin_lock(&port->irq_lock); + + port->saved_irq_state = readl_relaxed(port->base + PCIE_INT_ENABLE_REG); + + for (i = 0; i < PCIE_MSI_SET_NUM; i++) { + struct mtk_msi_set *msi_set = &port->msi_sets[i]; + + msi_set->saved_irq_state = readl_relaxed(msi_set->base + + PCIE_MSI_SET_ENABLE_OFFSET); + } + + raw_spin_unlock(&port->irq_lock); +} + +static void __maybe_unused mtk_pcie_irq_restore(struct mtk_pcie_port *port) +{ + int i; + + raw_spin_lock(&port->irq_lock); + + writel_relaxed(port->saved_irq_state, port->base + PCIE_INT_ENABLE_REG); + + for (i = 0; i < PCIE_MSI_SET_NUM; i++) { + struct mtk_msi_set *msi_set = &port->msi_sets[i]; + + writel_relaxed(msi_set->saved_irq_state, + msi_set->base + PCIE_MSI_SET_ENABLE_OFFSET); + } + + raw_spin_unlock(&port->irq_lock); +} + +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, "cannot 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, "entered L2 states successfully"); + + mtk_pcie_irq_save(port); + mtk_pcie_power_down(port); + + return 0; +} + +static int __maybe_unused mtk_pcie_resume_noirq(struct device *dev) +{ + struct mtk_pcie_port *port = dev_get_drvdata(dev); + int err; + + err = mtk_pcie_power_up(port); + if (err) + return err; + + err = mtk_pcie_startup_port(port); + if (err) { + mtk_pcie_power_down(port); + return err; + } + + mtk_pcie_irq_restore(port); + + 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" }, {}, @@ -905,6 +1017,7 @@ static struct platform_driver mtk_pcie_driver = { .driver = { .name = "mtk-pcie", .of_match_table = mtk_pcie_of_match, + .pm = &mtk_pcie_pm_ops, }, };