PCI: dwc: Move link handling into common code

All the DWC drivers do link setup and checks at roughly the same time.
Let's use the existing .start_link() hook (currently only used in EP
mode) and move the link handling to the core code.

The behavior for a link down was inconsistent as some drivers would fail
probe in that case while others succeed. Let's standardize this to
succeed as there are usecases where devices (and the link) appear later
even without hotplug. For example, a reconfigured FPGA device.

Link: https://lore.kernel.org/r/20201105211159.1814485-11-robh@kernel.org
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Richard Zhu <hongxing.zhu@nxp.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Pengutronix Kernel Team <kernel@pengutronix.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP Linux Team <linux-imx@nxp.com>
Cc: Murali Karicheri <m-karicheri2@ti.com>
Cc: Yue Wang <yue.wang@Amlogic.com>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Neil Armstrong <narmstrong@baylibre.com>
Cc: Jerome Brunet <jbrunet@baylibre.com>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Cc: Xiaowei Song <songxiaowei@hisilicon.com>
Cc: Binghui Wang <wangbinghui@hisilicon.com>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Stanimir Varbanov <svarbanov@mm-sol.com>
Cc: Pratyush Anand <pratyush.anand@gmail.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: linux-omap@vger.kernel.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-amlogic@lists.infradead.org
Cc: linux-arm-kernel@axis.com
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-tegra@vger.kernel.org

1 files changed, 20 insertions, 26 deletions

diff --git a/drivers/pci/controller/dwc/pcie-spear13xx.c b/drivers/pci/controller/dwc/pcie-spear13xx.c
index 800c34a60a33..ebbaa06fc8ab 100644
--- a/drivers/pci/controller/dwc/pcie-spear13xx.c
+++ b/drivers/pci/controller/dwc/pcie-spear13xx.c
@@ -66,32 +66,10 @@ struct pcie_app_reg {
 
 #define to_spear13xx_pcie(x)	dev_get_drvdata((x)->dev)
 
-static int spear13xx_pcie_establish_link(struct spear13xx_pcie *spear13xx_pcie)
+static int spear13xx_pcie_start_link(struct dw_pcie *pci)
 {
-	struct dw_pcie *pci = spear13xx_pcie->pci;
-	struct pcie_port *pp = &pci->pp;
+	struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pci);
 	struct pcie_app_reg *app_reg = spear13xx_pcie->app_base;
-	u32 val;
-	u32 exp_cap_off = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
-
-	if (dw_pcie_link_up(pci)) {
-		dev_err(pci->dev, "link already up\n");
-		return 0;
-	}
-
-	dw_pcie_setup_rc(pp);
-
-	/*
-	 * this controller support only 128 bytes read size, however its
-	 * default value in capability register is 512 bytes. So force
-	 * it to 128 here.
-	 */
-	val = dw_pcie_readw_dbi(pci, exp_cap_off + PCI_EXP_DEVCTL);
-	val &= ~PCI_EXP_DEVCTL_READRQ;
-	dw_pcie_writew_dbi(pci, exp_cap_off + PCI_EXP_DEVCTL, val);
-
-	dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, 0x104A);
-	dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, 0xCD80);
 
 	/* enable ltssm */
 	writel(DEVICE_TYPE_RC | (1 << MISCTRL_EN_ID)
@@ -99,7 +77,7 @@ static int spear13xx_pcie_establish_link(struct spear13xx_pcie *spear13xx_pcie)
 			| ((u32)1 << REG_TRANSLATION_ENABLE),
 			&app_reg->app_ctrl_0);
 
-	return dw_pcie_wait_for_link(pci);
+	return 0;
 }
 
 static irqreturn_t spear13xx_pcie_irq_handler(int irq, void *arg)
@@ -151,10 +129,25 @@ static int spear13xx_pcie_host_init(struct pcie_port *pp)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct spear13xx_pcie *spear13xx_pcie = to_spear13xx_pcie(pci);
+	u32 exp_cap_off = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP);
+	u32 val;
 
 	spear13xx_pcie->app_base = pci->dbi_base + 0x2000;
 
-	spear13xx_pcie_establish_link(spear13xx_pcie);
+	dw_pcie_setup_rc(pp);
+
+	/*
+	 * this controller support only 128 bytes read size, however its
+	 * default value in capability register is 512 bytes. So force
+	 * it to 128 here.
+	 */
+	val = dw_pcie_readw_dbi(pci, exp_cap_off + PCI_EXP_DEVCTL);
+	val &= ~PCI_EXP_DEVCTL_READRQ;
+	dw_pcie_writew_dbi(pci, exp_cap_off + PCI_EXP_DEVCTL, val);
+
+	dw_pcie_writew_dbi(pci, PCI_VENDOR_ID, 0x104A);
+	dw_pcie_writew_dbi(pci, PCI_DEVICE_ID, 0xCD80);
+
 	spear13xx_pcie_enable_interrupts(spear13xx_pcie);
 
 	return 0;
@@ -198,6 +191,7 @@ static int spear13xx_add_pcie_port(struct spear13xx_pcie *spear13xx_pcie,
 
 static const struct dw_pcie_ops dw_pcie_ops = {
 	.link_up = spear13xx_pcie_link_up,
+	.start_link = spear13xx_pcie_start_link,
 };
 
 static int spear13xx_pcie_probe(struct platform_device *pdev)