Changed orange-fork

vendor/periph.io/x/host/v3/allwinner/address.go

@@ -0,0 +1,102 @@
+package allwinner
+
+import (
+	"errors"
+	"os"
+	"path"
+	"regexp"
+	"strconv"
+	"strings"
+)
+
+// getBaseAddress queries the virtual file system to retrieve the base address
+// of the GPIO registers for GPIO pins in groups PA to PI.
+//
+// Defaults to 0x01C20800 as per datasheet if it could not query the file
+// system.
+func getBaseAddress() (uint64, error) {
+	driverDir := "/sys/bus/platform/drivers"
+	if IsH6() {
+		return getBaseAddressForH6CPU(driverDir)
+	}
+	return getDefaultBaseAddress(driverDir), nil
+}
+
+func getDefaultBaseAddress(driverDir string) uint64 {
+	base := uint64(0x01C20800)
+	link, err := os.Readlink(path.Join(driverDir, "sun50i-pinctrl/driver"))
+	if err != nil {
+		return base
+	}
+	parts := strings.SplitN(path.Base(link), ".", 2)
+	if len(parts) != 2 {
+		return base
+	}
+	base2, err := strconv.ParseUint(parts[0], 16, 64)
+	if err != nil {
+		return base
+	}
+	return base2
+}
+
+func getBaseAddressForH6CPU(driverDir string) (uint64, error) {
+	items, err := os.ReadDir(driverDir)
+	if err != nil {
+		return 0, err
+	}
+	return getBaseAddressFromDirItemsForH6CPU(driverDir, items)
+}
+
+func getBaseAddressFromDirItemsForH6CPU(root string, items []os.DirEntry) (uint64, error) {
+	for _, item := range items {
+		if ret, ok := getBaseAddressFromDirItemForH6CPU(root, item); ok {
+			return ret, nil
+		}
+
+	}
+	return 0, errors.New("file with base address not found")
+}
+
+func getBaseAddressFromDirItemForH6CPU(root string, item os.DirEntry) (uint64, bool) {
+	if !item.IsDir() {
+		return 0, false
+	}
+
+	if matched, _ := regexp.MatchString(`^sun50i-h6\d*-pinctrl$`, item.Name()); !matched {
+		return 0, false
+	}
+
+	return extractBaseAddressFromDriverDirForH6CPU(path.Join(root, item.Name()))
+}
+
+func extractBaseAddressFromDriverDirForH6CPU(dir string) (uint64, bool) {
+	if fileInfo, err := os.Stat(dir); err != nil || !fileInfo.IsDir() {
+		return 0, false
+	}
+	items, err := os.ReadDir(dir)
+	if err != nil {
+		return 0, false
+	}
+	for _, item := range items {
+		if address, ok := extractBaseAddress(item); ok {
+			return address, ok
+		}
+	}
+	return 0, false
+}
+
+func extractBaseAddress(item os.DirEntry) (uint64, bool) {
+	if item.IsDir() {
+		return 0, false
+	}
+	if !strings.HasSuffix(item.Name(), ".pinctrl") {
+		return 0, false
+	}
+	prefix := item.Name()[:len(item.Name())-len(".pinctrl")]
+	if address, err := strconv.ParseUint(prefix, 16, 64); err != nil {
+		return 0, false
+	} else {
+		return address, true
+	}
+
+}