From patchwork Mon Nov 18 09:54:31 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tony Chuang X-Patchwork-Id: 11249231 X-Patchwork-Delegate: kvalo@adurom.com 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 DBD1F1393 for ; Mon, 18 Nov 2019 09:54:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C23D52071C for ; Mon, 18 Nov 2019 09:54:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726563AbfKRJyo (ORCPT ); Mon, 18 Nov 2019 04:54:44 -0500 Received: from rtits2.realtek.com ([211.75.126.72]:40037 "EHLO rtits2.realtek.com.tw" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726488AbfKRJyo (ORCPT ); Mon, 18 Nov 2019 04:54:44 -0500 Authenticated-By: X-SpamFilter-By: BOX Solutions SpamTrap 5.62 with qID xAI9scDr018260, This message is accepted by code: ctloc85258 Received: from mail.realtek.com (RTITCASV01.realtek.com.tw[172.21.6.18]) by rtits2.realtek.com.tw (8.15.2/2.57/5.78) with ESMTPS id xAI9scDr018260 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=NOT); Mon, 18 Nov 2019 17:54:38 +0800 Received: from localhost.localdomain (172.21.68.126) by RTITCASV01.realtek.com.tw (172.21.6.18) with Microsoft SMTP Server id 14.3.468.0; Mon, 18 Nov 2019 17:54:38 +0800 From: To: CC: , Subject: [PATCH v2 3/4] rtw88: pci: enable CLKREQ function if host supports it Date: Mon, 18 Nov 2019 17:54:31 +0800 Message-ID: <20191118095432.4507-4-yhchuang@realtek.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191118095432.4507-1-yhchuang@realtek.com> References: <20191118095432.4507-1-yhchuang@realtek.com> MIME-Version: 1.0 X-Originating-IP: [172.21.68.126] Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org From: Yan-Hsuan Chuang By Realtek's design, there are two HW modules associated for CLKREQ, one is responsible to follow the PCIE host settings, and another is to actually working on it. But the module that is actually working on it is default disabled, and driver should enable that module if host and device have successfully sync'ed with each other. The module is default disabled because sometimes the host does not support it, and if there is any incorrect settings (ex. CLKREQ# is not Bi-Direction), device can be lost and disconnected to the host. So driver should first check after host and device are sync'ed, and the host does support the function and set it in configuration space, then driver can turn on the HW module to working on it. Signed-off-by: Yan-Hsuan Chuang Reviewed-by: Chris Chiu --- v1 -> v2 * slightly modify code flow of rtw_dbi_read8() to look cleaner drivers/net/wireless/realtek/rtw88/pci.c | 80 ++++++++++++++++++++++++ drivers/net/wireless/realtek/rtw88/pci.h | 5 ++ 2 files changed, 85 insertions(+) diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c index 6d1aa6f41e84..6e99aad39487 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.c +++ b/drivers/net/wireless/realtek/rtw88/pci.c @@ -1081,6 +1081,30 @@ static void rtw_dbi_write8(struct rtw_dev *rtwdev, u16 addr, u8 data) WARN(flag, "failed to write to DBI register, addr=0x%04x\n", addr); } +static int rtw_dbi_read8(struct rtw_dev *rtwdev, u16 addr, u8 *value) +{ + u16 read_addr = addr & BITS_DBI_ADDR_MASK; + u8 flag; + u8 cnt; + + rtw_write16(rtwdev, REG_DBI_FLAG_V1, read_addr); + rtw_write8(rtwdev, REG_DBI_FLAG_V1 + 2, BIT_DBI_RFLAG >> 16); + + for (cnt = 0; cnt < RTW_PCI_WR_RETRY_CNT; cnt++) { + flag = rtw_read8(rtwdev, REG_DBI_FLAG_V1 + 2); + if (flag == 0) { + read_addr = REG_DBI_RDATA_V1 + (addr & 3); + *value = rtw_read8(rtwdev, read_addr); + return 0; + } + + udelay(10); + } + + WARN(1, "failed to read DBI register, addr=0x%04x\n", addr); + return -EIO; +} + static void rtw_mdio_write(struct rtw_dev *rtwdev, u8 addr, u16 data, bool g1) { u8 page; @@ -1107,6 +1131,60 @@ static void rtw_mdio_write(struct rtw_dev *rtwdev, u8 addr, u16 data, bool g1) WARN(wflag, "failed to write to MDIO register, addr=0x%02x\n", addr); } +static void rtw_pci_clkreq_set(struct rtw_dev *rtwdev, bool enable) +{ + u8 value; + int ret; + + ret = rtw_dbi_read8(rtwdev, RTK_PCIE_LINK_CFG, &value); + if (ret) { + rtw_err(rtwdev, "failed to read CLKREQ_L1, ret=%d", ret); + return; + } + + if (enable) + value |= BIT_CLKREQ_SW_EN; + else + value &= ~BIT_CLKREQ_SW_EN; + + rtw_dbi_write8(rtwdev, RTK_PCIE_LINK_CFG, value); +} + +static void rtw_pci_link_cfg(struct rtw_dev *rtwdev) +{ + struct rtw_pci *rtwpci = (struct rtw_pci *)rtwdev->priv; + struct pci_dev *pdev = rtwpci->pdev; + u16 link_ctrl; + int ret; + + /* Though there is standard PCIE configuration space to set the + * link control register, but by Realtek's design, driver should + * check if host supports CLKREQ/ASPM to enable the HW module. + * + * These functions are implemented by two HW modules associated, + * one is responsible to access PCIE configuration space to + * follow the host settings, and another is in charge of doing + * CLKREQ/ASPM mechanisms, it is default disabled. Because sometimes + * the host does not support it, and due to some reasons or wrong + * settings (ex. CLKREQ# not Bi-Direction), it could lead to device + * loss if HW misbehaves on the link. + * + * Hence it's designed that driver should first check the PCIE + * configuration space is sync'ed and enabled, then driver can turn + * on the other module that is actually working on the mechanism. + */ + ret = pcie_capability_read_word(pdev, PCI_EXP_LNKCTL, &link_ctrl); + if (ret) { + rtw_err(rtwdev, "failed to read PCI cap, ret=%d\n", ret); + return; + } + + if (link_ctrl & PCI_EXP_LNKCTL_CLKREQ_EN) + rtw_pci_clkreq_set(rtwdev, true); + + rtwpci->link_ctrl = link_ctrl; +} + static void rtw_pci_phy_cfg(struct rtw_dev *rtwdev) { struct rtw_chip_info *chip = rtwdev->chip; @@ -1145,6 +1223,8 @@ static void rtw_pci_phy_cfg(struct rtw_dev *rtwdev) else rtw_dbi_write8(rtwdev, offset, value); } + + rtw_pci_link_cfg(rtwdev); } static int rtw_pci_claim(struct rtw_dev *rtwdev, struct pci_dev *pdev) diff --git a/drivers/net/wireless/realtek/rtw88/pci.h b/drivers/net/wireless/realtek/rtw88/pci.h index 50aff49738d4..90efb73c607e 100644 --- a/drivers/net/wireless/realtek/rtw88/pci.h +++ b/drivers/net/wireless/realtek/rtw88/pci.h @@ -20,6 +20,7 @@ #define BIT_RST_TRXDMA_INTF BIT(20) #define BIT_RX_TAG_EN BIT(15) #define REG_DBI_WDATA_V1 0x03E8 +#define REG_DBI_RDATA_V1 0x03EC #define REG_DBI_FLAG_V1 0x03F0 #define BIT_DBI_RFLAG BIT(17) #define BIT_DBI_WFLAG BIT(16) @@ -35,6 +36,9 @@ #define RTW_PCI_MDIO_PG_OFFS_G2 2 #define RTW_PCI_WR_RETRY_CNT 20 +#define RTK_PCIE_LINK_CFG 0x0719 +#define BIT_CLKREQ_SW_EN BIT(4) + #define BIT_PCI_BCNQ_FLAG BIT(4) #define RTK_PCI_TXBD_DESA_BCNQ 0x308 #define RTK_PCI_TXBD_DESA_H2CQ 0x1320 @@ -200,6 +204,7 @@ struct rtw_pci { u16 rx_tag; struct rtw_pci_tx_ring tx_rings[RTK_MAX_TX_QUEUE_NUM]; struct rtw_pci_rx_ring rx_rings[RTK_MAX_RX_QUEUE_NUM]; + u16 link_ctrl; void __iomem *mmap; };