ARM: mvebu: Add thermal quirk for the Armada 375 DB board

The initial release of the Armada 375 DB board has an Armada 375
Z1 stepping silicon. This commit introduces a quirk that allows
to workaround a series of issues with the thermal sensor in this
stepping, but updating the devicetree:

  * Updates the compatible string for the thermal, so the driver
    can perform a specific initialization of the sensor.

  * Moves the offset of the thermal control register. This quirk
    allows to specifiy the correct (A0 stepping) offset in the
    devicetree.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Link: https://lkml.kernel.org/r/1398371004-15807-9-git-send-email-ezequiel.garcia@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

2 files changed, 60 insertions, 0 deletions

diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c
index c8a90d992be2..bc0283f0dd88 100644
--- a/arch/arm/mach-mvebu/board-v7.c
+++ b/arch/arm/mach-mvebu/board-v7.c
@@ -113,10 +113,66 @@ static void __init i2c_quirk(void)
         return;
 }
 
+#define A375_Z1_THERMAL_FIXUP_OFFSET 0xc
+
+static void __init thermal_quirk(void)
+{
+        struct device_node *np;
+        u32 dev, rev;
+
+        if (mvebu_get_soc_id(&dev, &rev) && rev > ARMADA_375_Z1_REV)
+                return;
+
+        for_each_compatible_node(np, NULL, "marvell,armada375-thermal") {
+                struct property *prop;
+                __be32 newval, *newprop, *oldprop;
+                int len;
+
+                /*
+                 * The register offset is at a wrong location. This quirk
+                 * creates a new reg property as a clone of the previous
+                 * one and corrects the offset.
+                 */
+                oldprop = (__be32 *)of_get_property(np, "reg", &len);
+                if (!oldprop)
+                        continue;
+
+                /* Create a duplicate of the 'reg' property */
+                prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+                prop->length = len;
+                prop->name = kstrdup("reg", GFP_KERNEL);
+                prop->value = kzalloc(len, GFP_KERNEL);
+                memcpy(prop->value, oldprop, len);
+
+                /* Fixup the register offset of the second entry */
+                oldprop += 2;
+                newprop = (__be32 *)prop->value + 2;
+                newval = cpu_to_be32(be32_to_cpu(*oldprop) -
+                                     A375_Z1_THERMAL_FIXUP_OFFSET);
+                *newprop = newval;
+                of_update_property(np, prop);
+
+                /*
+                 * The thermal controller needs some quirk too, so let's change
+                 * the compatible string to reflect this.
+                 */
+                prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+                prop->name = kstrdup("compatible", GFP_KERNEL);
+                prop->length = sizeof("marvell,armada375-z1-thermal");
+                prop->value = kstrdup("marvell,armada375-z1-thermal",
+                                                GFP_KERNEL);
+                of_update_property(np, prop);
+        }
+        return;
+}
+
 static void __init mvebu_dt_init(void)
 {
         if (of_machine_is_compatible("plathome,openblocks-ax3-4"))
                 i2c_quirk();
+        if (of_machine_is_compatible("marvell,a375-db"))
+                thermal_quirk();
+
         of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
 }
 
@@ -140,6 +196,7 @@ static const char * const armada_375_dt_compat[] = {
 
 DT_MACHINE_START(ARMADA_375_DT, "Marvell Armada 375 (Device Tree)")
         .init_time      = mvebu_timer_and_clk_init,
+        .init_machine   = mvebu_dt_init,
         .restart        = mvebu_restart,
         .dt_compat      = armada_375_dt_compat,
 MACHINE_END
diff --git a/arch/arm/mach-mvebu/mvebu-soc-id.h b/arch/arm/mach-mvebu/mvebu-soc-id.h
index 31654252fe35..294a443f56fc 100644
--- a/arch/arm/mach-mvebu/mvebu-soc-id.h
+++ b/arch/arm/mach-mvebu/mvebu-soc-id.h
@@ -20,6 +20,9 @@
 #define MV78XX0_A0_REV      0x1
 #define MV78XX0_B0_REV      0x2
 
+/* Armada 375 */
+#define ARMADA_375_Z1_REV   0x0
+
 #ifdef CONFIG_ARCH_MVEBU
 int mvebu_get_soc_id(u32 *dev, u32 *rev);
 #else