[PATCH 04/10] x86, olpc: Use a correct version when making up a battery node

[Lubomir Rintel]

The XO-1 and XO-1.5 batteries apparently differ in an ability to report
ambient temperature. We need to use a different compatible string for the
XO-1.5 battery.

Previously olpc_dt_fixup() used the presence od the battery node's
compatible property to decide whether the DT is up to date. Now we need
to look for a particular value in the compatible string, to decide

Signed-off-by: Lubomir Rintel <lkund...@v3.sk>
Acked-by: Pavel Machek <pa...@ucw.cz>

---
Changes since v5:
- Split the "x86, olpc: Don't split string literals when fixing up the DT"
  and "x86, olpc: trivial code move in DT fixup" parts off from this
- Clarify some comments

Changes since v1:
- Avoid splitting string literals

 arch/x86/platform/olpc/olpc_dt.c | 64 +++++++++++++++++++++++++-------
 1 file changed, 50 insertions(+), 14 deletions(-)

diff --git a/arch/x86/platform/olpc/olpc_dt.c b/arch/x86/platform/olpc/olpc_dt.c
index adf98b5623c0..1728f8992850 100644
--- a/arch/x86/platform/olpc/olpc_dt.c
+++ b/arch/x86/platform/olpc/olpc_dt.c
@@ -217,10 +217,28 @@ static u32 __init olpc_dt_get_board_revision(void)
        return be32_to_cpu(rev);
 }
 
+int olpc_dt_compatible_match(phandle node, const char *compat)
+{
+       char buf[64];
+       int plen;
+       char *p;
+       int len;
+
+       plen = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf));
+       if (plen <= 0)
+               return 0;
+
+       len = strlen(compat);
+       for (p = buf; p < buf + plen; p += strlen(p) + 1) {
+               if (strcmp(p, compat) == 0)
+                       return 1;
+       }
+
+       return 0;
+}
+
 void __init olpc_dt_fixup(void)
 {
-       int r;
-       char buf[64];
        phandle node;
        u32 board_rev;
 
@@ -228,22 +246,30 @@ void __init olpc_dt_fixup(void)
        if (!node)
                return;
 
-       /*
-        * If the battery node has a compatible property, we are running a new
-        * enough firmware and don't have fixups to make.
-        */
-       r = olpc_dt_getproperty(node, "compatible", buf, sizeof(buf));
-       if (r > 0)
-               return;
-
-       pr_info("PROM DT: Old firmware detected, applying fixes\n");
-
        board_rev = olpc_dt_get_board_revision();
        if (!board_rev)
                return;
 
        if (board_rev >= olpc_board_pre(0xd0)) {
-               /* XO-1.5: add dcon device */
+               /* XO-1.5 */
+
+               if (olpc_dt_compatible_match(node, "olpc,xo1.5-battery"))
+                       return;
+
+               /* Add olpc,xo1.5-battery compatible marker to battery node */
+               olpc_dt_interpret("\" /battery@0\" find-device");
+               olpc_dt_interpret("  \" olpc,xo1.5-battery\" +compatible");
+               olpc_dt_interpret("device-end");
+
+               if (olpc_dt_compatible_match(node, "olpc,xo1-battery")) {
+                       /* If we have a olpc,xo1-battery compatible, then we're
+                        * running a new enough firmware that already has
+                        * the dcon node.
+                        */
+                       return;
+               }
+
+               /* Add dcon device */
                olpc_dt_interpret("\" /pci/display@1\" find-device");
                olpc_dt_interpret("  new-device");
                olpc_dt_interpret("    \" dcon\" device-name");
@@ -251,7 +277,17 @@ void __init olpc_dt_fixup(void)
                olpc_dt_interpret("  finish-device");
                olpc_dt_interpret("device-end");
        } else {
-               /* XO-1: add dcon device, mark RTC as olpc,xo1-rtc */
+               /* XO-1 */
+
+               if (olpc_dt_compatible_match(node, "olpc,xo1-battery")) {
+                       /* If we have a olpc,xo1-battery compatible, then we're
+                        * running a new enough firmware that already has
+                        * the dcon and RTC nodes.
+                        */
+                       return;
+               }
+
+               /* Add dcon device, mark RTC as olpc,xo1-rtc */
                olpc_dt_interpret("\" /pci/display@1,1\" find-device");
                olpc_dt_interpret("  new-device");
                olpc_dt_interpret("    \" dcon\" device-name");
-- 
2.20.1