[PATCH v4 5/7] PCI: dwc: all: Modify dbi accessors to access data of 4/2/1 bytes

[Kishon Vijay Abraham I]

Previously dbi accessors can be used to access data of size 4
bytes. But there might be situations (like accessing
MSI_MESSAGE_CONTROL in order to set/get the number of required
MSI interrupts in EP mode) where dbi accessors must
be used to access data of size 2. This is in preparation for
adding endpoint mode support to designware driver.

Cc: Jingoo Han <jingoohan1@xxxxxxxxx>
Cc: Joao Pinto <Joao.Pinto@xxxxxxxxxxxx>
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
 drivers/pci/dwc/pci-exynos.c      | 16 ++++++++--------
 drivers/pci/dwc/pcie-designware.c | 34 ++++++++++++++++++++++++----------
 drivers/pci/dwc/pcie-designware.h | 20 +++++++++++---------
 3 files changed, 43 insertions(+), 27 deletions(-)

diff --git a/drivers/pci/dwc/pci-exynos.c b/drivers/pci/dwc/pci-exynos.c
index a0d40f74b88d..37d6d2b7378f 100644
--- a/drivers/pci/dwc/pci-exynos.c
+++ b/drivers/pci/dwc/pci-exynos.c
@@ -521,25 +521,25 @@ static void exynos_pcie_enable_interrupts(struct exynos_pcie *ep)
 		exynos_pcie_msi_init(ep);
 }
 
-static u32 exynos_pcie_readl_dbi(struct dw_pcie *pci, void __iomem *base,
-				 u32 reg)
+static u32 exynos_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base,
+				u32 reg, size_t size)
 {
 	struct exynos_pcie *ep = to_exynos_pcie(pci);
 	u32 val;
 
 	exynos_pcie_sideband_dbi_r_mode(ep, true);
-	val = readl(base + reg);
+	dw_pcie_read(base + reg, size, &val);
 	exynos_pcie_sideband_dbi_r_mode(ep, false);
 	return val;
 }
 
-static void exynos_pcie_writel_dbi(struct dw_pcie *pci, void __iomem *base,
-				   u32 reg, u32 val)
+static void exynos_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base,
+				  u32 reg, size_t size, u32 val)
 {
 	struct exynos_pcie *ep = to_exynos_pcie(pci);
 
 	exynos_pcie_sideband_dbi_w_mode(ep, true);
-	writel(val, base + reg);
+	dw_pcie_write(base + reg, size, val);
 	exynos_pcie_sideband_dbi_w_mode(ep, false);
 }
 
@@ -646,8 +646,8 @@ static int __init exynos_add_pcie_port(struct exynos_pcie *ep,
 }
 
 static const struct dw_pcie_ops dw_pcie_ops = {
-	.readl_dbi = exynos_pcie_readl_dbi,
-	.writel_dbi = exynos_pcie_writel_dbi,
+	.read_dbi = exynos_pcie_read_dbi,
+	.write_dbi = exynos_pcie_write_dbi,
 	.link_up = exynos_pcie_link_up,
 };
 
diff --git a/drivers/pci/dwc/pcie-designware.c b/drivers/pci/dwc/pcie-designware.c
index ea403e2240cf..734acac1926d 100644
--- a/drivers/pci/dwc/pcie-designware.c
+++ b/drivers/pci/dwc/pcie-designware.c
@@ -61,21 +61,35 @@ int dw_pcie_write(void __iomem *addr, int size, u32 val)
 	return PCIBIOS_SUCCESSFUL;
 }
 
-u32 __dw_pcie_readl_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg)
+u32 __dw_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
+		       size_t size)
 {
-	if (pci->ops->readl_dbi)
-		return pci->ops->readl_dbi(pci, base, reg);
+	int ret;
+	u32 val;
+
+	if (pci->ops->read_dbi)
+		return pci->ops->read_dbi(pci, base, reg, size);
 
-	return readl(base + reg);
+	ret = dw_pcie_read(base + reg, size, &val);
+	if (ret)
+		dev_err(pci->dev, "read DBI address failed\n");
+
+	return val;
 }
 
-void __dw_pcie_writel_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
-			  u32 val)
+void __dw_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
+			 size_t size, u32 val)
 {
-	if (pci->ops->writel_dbi)
-		pci->ops->writel_dbi(pci, base, reg, val);
-	else
-		writel(val, base + reg);
+	int ret;
+
+	if (pci->ops->write_dbi) {
+		pci->ops->write_dbi(pci, base, reg, size, val);
+		return;
+	}
+
+	ret = dw_pcie_write(base + reg, size, val);
+	if (ret)
+		dev_err(pci->dev, "write DBI address failed\n");
 }
 
 static u32 dw_pcie_readl_unroll(struct dw_pcie *pci, u32 index, u32 reg)
diff --git a/drivers/pci/dwc/pcie-designware.h b/drivers/pci/dwc/pcie-designware.h
index e97fc4ce7d49..bfaf2b850a88 100644
--- a/drivers/pci/dwc/pcie-designware.h
+++ b/drivers/pci/dwc/pcie-designware.h
@@ -144,9 +144,10 @@ struct pcie_port {
 
 struct dw_pcie_ops {
 	u64	(*cpu_addr_fixup)(u64 cpu_addr);
-	u32	(*readl_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg);
-	void	(*writel_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
-			      u32 val);
+	u32	(*read_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
+			    size_t size);
+	void	(*write_dbi)(struct dw_pcie *pcie, void __iomem *base, u32 reg,
+			     size_t size, u32 val);
 	int	(*link_up)(struct dw_pcie *pcie);
 };
 
@@ -164,9 +165,10 @@ struct dw_pcie {
 int dw_pcie_read(void __iomem *addr, int size, u32 *val);
 int dw_pcie_write(void __iomem *addr, int size, u32 val);
 
-u32 __dw_pcie_readl_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg);
-void __dw_pcie_writel_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
-			  u32 val);
+u32 __dw_pcie_read_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
+		       size_t size);
+void __dw_pcie_write_dbi(struct dw_pcie *pci, void __iomem *base, u32 reg,
+			 size_t size, u32 val);
 int dw_pcie_link_up(struct dw_pcie *pci);
 int dw_pcie_wait_for_link(struct dw_pcie *pci);
 void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index,
@@ -174,14 +176,14 @@ void dw_pcie_prog_outbound_atu(struct dw_pcie *pci, int index,
 			       u32 size);
 void dw_pcie_setup(struct dw_pcie *pci);
 
-static inline dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val)
+static inline void dw_pcie_writel_dbi(struct dw_pcie *pci, u32 reg, u32 val)
 {
-	__dw_pcie_writel_dbi(pci, pci->dbi_base, reg, val);
+	__dw_pcie_write_dbi(pci, pci->dbi_base, reg, 0x4, val);
 }
 
 static inline u32 dw_pcie_readl_dbi(struct dw_pcie *pci, u32 reg)
 {
-	return  __dw_pcie_readl_dbi(pci, pci->dbi_base, reg);
+	return __dw_pcie_read_dbi(pci, pci->dbi_base, reg, 0x4);
 }
 
 #ifdef CONFIG_PCIE_DW_HOST
-- 
2.11.0