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From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Date: Mon, 26 Feb 2024 17:07:26 +0530
Subject: [PATCH v3 1/5] PCI: dwc: Refactor dw_pcie_edma_find_chip() API
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Message-Id: <20240226-dw-hdma-v3-1-cfcb8171fc24@linaro.org>
References: <20240226-dw-hdma-v3-0-cfcb8171fc24@linaro.org>
In-Reply-To: <20240226-dw-hdma-v3-0-cfcb8171fc24@linaro.org>
To: Jingoo Han <jingoohan1@gmail.com>, 
 Gustavo Pimentel <gustavo.pimentel@synopsys.com>, 
 Lorenzo Pieralisi <lpieralisi@kernel.org>, 
 =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= <kw@linux.com>, 
 Rob Herring <robh@kernel.org>, Bjorn Helgaas <bhelgaas@google.com>, 
 Marek Vasut <marek.vasut+renesas@gmail.com>, 
 Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>, 
 Kishon Vijay Abraham I <kishon@kernel.org>
Cc: Serge Semin <fancer.lancer@gmail.com>, linux-pci@vger.kernel.org, 
 linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org, 
 linux-arm-msm@vger.kernel.org, mhi@lists.linux.dev, 
 Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

In order to add support for Hyper DMA (HDMA), let's refactor the existing
dw_pcie_edma_find_chip() API by moving the common code to separate
functions.

No functional change.

Suggested-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/pci/controller/dwc/pcie-designware.c | 52 +++++++++++++++++++++-------
 1 file changed, 39 insertions(+), 13 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
index 250cf7f40b85..193fcd86cf93 100644
--- a/drivers/pci/controller/dwc/pcie-designware.c
+++ b/drivers/pci/controller/dwc/pcie-designware.c
@@ -880,7 +880,17 @@ static struct dw_edma_plat_ops dw_pcie_edma_ops = {
 	.irq_vector = dw_pcie_edma_irq_vector,
 };
 
-static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
+static void dw_pcie_edma_init_data(struct dw_pcie *pci)
+{
+	pci->edma.dev = pci->dev;
+
+	if (!pci->edma.ops)
+		pci->edma.ops = &dw_pcie_edma_ops;
+
+	pci->edma.flags |= DW_EDMA_CHIP_LOCAL;
+}
+
+static int dw_pcie_edma_find_mf(struct dw_pcie *pci)
 {
 	u32 val;
 
@@ -900,24 +910,27 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
 	else
 		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
 
-	if (val == 0xFFFFFFFF && pci->edma.reg_base) {
-		pci->edma.mf = EDMA_MF_EDMA_UNROLL;
-
-		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
-	} else if (val != 0xFFFFFFFF) {
-		pci->edma.mf = EDMA_MF_EDMA_LEGACY;
+	/* Set default mapping format here and update it below if needed */
+	pci->edma.mf = EDMA_MF_EDMA_LEGACY;
 
+	if (val == 0xFFFFFFFF && pci->edma.reg_base)
+		pci->edma.mf = EDMA_MF_EDMA_UNROLL;
+	else if (val != 0xFFFFFFFF)
 		pci->edma.reg_base = pci->dbi_base + PCIE_DMA_VIEWPORT_BASE;
-	} else {
+	else
 		return -ENODEV;
-	}
 
-	pci->edma.dev = pci->dev;
+	return 0;
+}
 
-	if (!pci->edma.ops)
-		pci->edma.ops = &dw_pcie_edma_ops;
+static int dw_pcie_edma_find_channels(struct dw_pcie *pci)
+{
+	u32 val;
 
-	pci->edma.flags |= DW_EDMA_CHIP_LOCAL;
+	if (pci->edma.mf == EDMA_MF_EDMA_LEGACY)
+		val = dw_pcie_readl_dbi(pci, PCIE_DMA_VIEWPORT_BASE + PCIE_DMA_CTRL);
+	else
+		val = dw_pcie_readl_dma(pci, PCIE_DMA_CTRL);
 
 	pci->edma.ll_wr_cnt = FIELD_GET(PCIE_DMA_NUM_WR_CHAN, val);
 	pci->edma.ll_rd_cnt = FIELD_GET(PCIE_DMA_NUM_RD_CHAN, val);
@@ -930,6 +943,19 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
 	return 0;
 }
 
+static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
+{
+	int ret;
+
+	dw_pcie_edma_init_data(pci);
+
+	ret = dw_pcie_edma_find_mf(pci);
+	if (ret)
+		return ret;
+
+	return dw_pcie_edma_find_channels(pci);
+}
+
 static int dw_pcie_edma_irq_verify(struct dw_pcie *pci)
 {
 	struct platform_device *pdev = to_platform_device(pci->dev);

-- 
2.25.1