[PATCH V3] PCI: tegra: Fix building Tegra194 PCIe driver

[Jon Hunter <jonathanh@nvidia.com>]

Commit 7f100744749e ("PCI: tegra: Add Tegra194 MCFG quirks for ECAM
errata") caused a few build regressions for the Tegra194 PCIe driver
which are:

1. The Tegra194 PCIe driver can no longer be built as a module. This
   was caused by removing the Makefile entry to build the pcie-tegra.c
   based upon the CONFIG_PCIE_TEGRA194 option. Therefore, restore this
   so that we can build the driver as a module.
2. 7f100744749e ("PCI: tegra: Add Tegra194 MCFG quirks for ECAM
   errata") added "#ifdef CONFIG_PCIE_TEGRA194" around the native
   driver. But if we set CONFIG_PCIE_TEGRA194=m to build the driver as a
   module, autoconf.h contains "#define CONFIG_PCIE_TEGRA194_MODULE 1"
   (not "#define CONFIG_PCIE_TEGRA194 1"), so the #ifdef excludes the
   driver. Instead, use "IS_ENABLED(CONFIG_PCIE_TEGRA194)", which checks
   for either CONFIG_PCIE_TEGRA194 or CONFIG_PCIE_TEGRA194_MODULE.
3. The below build warnings that are seen with particular kernel
   configurations. Fix these by moving these structure definitions to
   within the necessary guards.

  drivers/pci/controller/dwc/pcie-tegra194.c:259:18: warning:
  	‘event_cntr_data_offset’ defined but not used [-Wunused-const-variable=]
  drivers/pci/controller/dwc/pcie-tegra194.c:250:18: warning:
  	‘event_cntr_ctrl_offset’ defined but not used [-Wunused-const-variable=]
  drivers/pci/controller/dwc/pcie-tegra194.c:243:27: warning:
  	‘pcie_gen_freq’ defined but not used [-Wunused-const-variable=]

Fixes: 7f100744749e ("PCI: tegra: Add Tegra194 MCFG quirks for ECAM errata")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
---
Changes since V2:
- Update the commit message per Bjorn's feedback
- Moved the structure definitions within the necessary guards as opposed
  to wrapping the existing defintions with the appropriate guards.

Changes since V1:
- Added fixes tag
- Fixed 'defined but not used' compiler warnings

 drivers/pci/controller/dwc/Makefile        |  1 +
 drivers/pci/controller/dwc/pcie-tegra194.c | 51 +++++++++++-----------
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/pci/controller/dwc/Makefile b/drivers/pci/controller/dwc/Makefile
index eca805c1a023..f0d1e2d8c022 100644
--- a/drivers/pci/controller/dwc/Makefile
+++ b/drivers/pci/controller/dwc/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_PCIE_UNIPHIER_EP) += pcie-uniphier-ep.o
 # depending on whether ACPI, the DT driver, or both are enabled.
 
 obj-$(CONFIG_PCIE_AL) += pcie-al.o
+obj-$(CONFIG_PCIE_TEGRA194) += pcie-tegra194.o
 obj-$(CONFIG_PCI_HISI) += pcie-hisi.o
 
 ifdef CONFIG_ACPI
diff --git a/drivers/pci/controller/dwc/pcie-tegra194.c b/drivers/pci/controller/dwc/pcie-tegra194.c
index b19775ab134e..9b3758ea1cba 100644
--- a/drivers/pci/controller/dwc/pcie-tegra194.c
+++ b/drivers/pci/controller/dwc/pcie-tegra194.c
@@ -240,31 +240,6 @@
 #define EP_STATE_DISABLED	0
 #define EP_STATE_ENABLED	1
 
-static const unsigned int pcie_gen_freq[] = {
-	GEN1_CORE_CLK_FREQ,
-	GEN2_CORE_CLK_FREQ,
-	GEN3_CORE_CLK_FREQ,
-	GEN4_CORE_CLK_FREQ
-};
-
-static const u32 event_cntr_ctrl_offset[] = {
-	0x1d8,
-	0x1a8,
-	0x1a8,
-	0x1a8,
-	0x1c4,
-	0x1d8
-};
-
-static const u32 event_cntr_data_offset[] = {
-	0x1dc,
-	0x1ac,
-	0x1ac,
-	0x1ac,
-	0x1c8,
-	0x1dc
-};
-
 struct tegra_pcie_dw {
 	struct device *dev;
 	struct resource *appl_res;
@@ -409,7 +384,13 @@ const struct pci_ecam_ops tegra194_pcie_ops = {
 };
 #endif /* defined(CONFIG_ACPI) && defined(CONFIG_PCI_QUIRKS) */
 
-#ifdef CONFIG_PCIE_TEGRA194
+#if IS_ENABLED(CONFIG_PCIE_TEGRA194)
+static const unsigned int pcie_gen_freq[] = {
+	GEN1_CORE_CLK_FREQ,
+	GEN2_CORE_CLK_FREQ,
+	GEN3_CORE_CLK_FREQ,
+	GEN4_CORE_CLK_FREQ
+};
 
 static inline struct tegra_pcie_dw *to_tegra_pcie(struct dw_pcie *pci)
 {
@@ -694,6 +675,24 @@ static struct pci_ops tegra_pci_ops = {
 };
 
 #if defined(CONFIG_PCIEASPM)
+static const u32 event_cntr_ctrl_offset[] = {
+	0x1d8,
+	0x1a8,
+	0x1a8,
+	0x1a8,
+	0x1c4,
+	0x1d8
+};
+
+static const u32 event_cntr_data_offset[] = {
+	0x1dc,
+	0x1ac,
+	0x1ac,
+	0x1ac,
+	0x1c8,
+	0x1dc
+};
+
 static void disable_aspm_l11(struct tegra_pcie_dw *pcie)
 {
 	u32 val;
-- 
2.25.1