Certain platforms like TI's J721E allows only 32-bit register accesses.
Add read and write accessor to perform only 32-bit accesses in order to
support platfroms like TI's J721E.
Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
drivers/pci/controller/pcie-cadence.c | 40 +++++++++++++++++++++++++++
drivers/pci/controller/pcie-cadence.h | 2 ++
2 files changed, 42 insertions(+)
diff --git a/drivers/pci/controller/pcie-cadence.c b/drivers/pci/controller/pcie-cadence.c
index cd795f6fc1e2..de5b3b06f2d0 100644
--- a/drivers/pci/controller/pcie-cadence.c
+++ b/drivers/pci/controller/pcie-cadence.c
@@ -7,6 +7,46 @@
#include "pcie-cadence.h"
+u32 cdns_pcie_read32(void __iomem *addr, int size)
+{
+ void __iomem *aligned_addr = PTR_ALIGN_DOWN(addr, 0x4);
+ unsigned int offset = (unsigned long)addr & 0x3;
+ u32 val = readl(aligned_addr);
+
+ if (!IS_ALIGNED((uintptr_t)addr, size)) {
+ pr_err("Invalid Address in function:%s\n", __func__);
+ return 0;
+ }
+
+ if (size > 2)
+ return val;
+
+ return (val >> (8 * offset)) & ((1 << (size * 8)) - 1);
+}
+
+void cdns_pcie_write32(void __iomem *addr, int size, u32 value)
+{
+ void __iomem *aligned_addr = PTR_ALIGN_DOWN(addr, 0x4);
+ unsigned int offset = (unsigned long)addr & 0x3;
+ u32 mask;
+ u32 val;
+
+ if (!IS_ALIGNED((uintptr_t)addr, size)) {
+ pr_err("Invalid Address in function:%s\n", __func__);
+ return;
+ }
+
+ if (size > 2) {
+ writel(value, addr);
+ return;
+ }
+
+ mask = ~(((1 << (size * 8)) - 1) << (offset * 8));
+ val = readl(aligned_addr) & mask;
+ val |= value << (offset * 8);
+ writel(val, aligned_addr);
+}
+
void cdns_pcie_set_outbound_region(struct cdns_pcie *pcie, u8 fn,
u32 r, bool is_io,
u64 cpu_addr, u64 pci_addr, size_t size)
diff --git a/drivers/pci/controller/pcie-cadence.h b/drivers/pci/controller/pcie-cadence.h
index 0134c1b1ad65..d157bf5eabd5 100644
--- a/drivers/pci/controller/pcie-cadence.h
+++ b/drivers/pci/controller/pcie-cadence.h
@@ -406,6 +406,8 @@ void cdns_pcie_reset_outbound_region(struct cdns_pcie *pcie, u32 r);
void cdns_pcie_disable_phy(struct cdns_pcie *pcie);
int cdns_pcie_enable_phy(struct cdns_pcie *pcie);
int cdns_pcie_init_phy(struct device *dev, struct cdns_pcie *pcie);
+u32 cdns_pcie_read32(void __iomem *addr, int size);
+void cdns_pcie_write32(void __iomem *addr, int size, u32 value);
extern const struct dev_pm_ops cdns_pcie_pm_ops;
#endif /* _PCIE_CADENCE_H */
--
2.17.1
