i2c/powermac: Improve detection of devices from device-tree

This patch adds a number of workarounds for broken Apple device-trees
mostly around sound chips. It handles creating the missing audio codec
devices and works around various issues with missing addresses or
missing compatible properties.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 133 insertions, 24 deletions

diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c
index 31c47e18d83c..5285f8565de4 100644
--- a/drivers/i2c/busses/i2c-powermac.c
+++ b/drivers/i2c/busses/i2c-powermac.c
@@ -227,28 +227,138 @@ static int __devexit i2c_powermac_remove(struct platform_device *dev)
         return 0;
 }
 
+static u32 __devinit i2c_powermac_get_addr(struct i2c_adapter *adap,
+                                           struct pmac_i2c_bus *bus,
+                                           struct device_node *node)
+{
+        const __be32 *prop;
+        int len;
+
+        /* First check for valid "reg" */
+        prop = of_get_property(node, "reg", &len);
+        if (prop && (len >= sizeof(int)))
+                return (be32_to_cpup(prop) & 0xff) >> 1;
+
+        /* Then check old-style "i2c-address" */
+        prop = of_get_property(node, "i2c-address", &len);
+        if (prop && (len >= sizeof(int)))
+                return (be32_to_cpup(prop) & 0xff) >> 1;
+
+        /* Now handle some devices with missing "reg" properties */
+        if (!strcmp(node->name, "cereal"))
+                return 0x60;
+        else if (!strcmp(node->name, "deq"))
+                return 0x34;
+
+        dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
+
+        return 0xffffffff;
+}
+
+static void __devinit i2c_powermac_create_one(struct i2c_adapter *adap,
+                                              const char *type,
+                                              u32 addr)
+{
+        struct i2c_board_info info = {};
+        struct i2c_client *newdev;
+
+        strncpy(info.type, type, sizeof(info.type));
+        info.addr = addr;
+        newdev = i2c_new_device(adap, &info);
+        if (!newdev)
+                dev_err(&adap->dev,
+                        "i2c-powermac: Failure to register missing %s\n",
+                        type);
+}
+
+static void __devinit i2c_powermac_add_missing(struct i2c_adapter *adap,
+                                               struct pmac_i2c_bus *bus,
+                                               bool found_onyx)
+{
+        struct device_node *busnode = pmac_i2c_get_bus_node(bus);
+        int rc;
+
+        /* Check for the onyx audio codec */
+#define ONYX_REG_CONTROL                67
+        if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
+                union i2c_smbus_data data;
+
+                rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
+                                    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
+                                    &data);
+                if (rc >= 0)
+                        i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
+
+                rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
+                                    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
+                                    &data);
+                if (rc >= 0)
+                        i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
+        }
+}
+
+static bool __devinit i2c_powermac_get_type(struct i2c_adapter *adap,
+                                            struct device_node *node,
+                                            u32 addr, char *type, int type_size)
+{
+        char tmp[16];
+
+        /* Note: we to _NOT_ want the standard
+         * i2c drivers to match with any of our powermac stuff
+         * unless they have been specifically modified to handle
+         * it on a case by case basis. For example, for thermal
+         * control, things like lm75 etc... shall match with their
+         * corresponding windfarm drivers, _NOT_ the generic ones,
+         * so we force a prefix of AAPL, onto the modalias to
+         * make that happen
+         */
+
+        /* First try proper modalias */
+        if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
+                snprintf(type, type_size, "MAC,%s", tmp);
+                return true;
+        }
+
+        /* Now look for known workarounds */
+        if (!strcmp(node->name, "deq")) {
+                /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
+                if (addr == 0x34) {
+                        snprintf(type, type_size, "MAC,tas3001");
+                        return true;
+                } else if (addr == 0x35) {
+                        snprintf(type, type_size, "MAC,tas3004");
+                        return true;
+                }
+        }
+
+        dev_err(&adap->dev, "i2c-powermac: modalias failure"
+                " on %s\n", node->full_name);
+        return false;
+}
+
 static void __devinit i2c_powermac_register_devices(struct i2c_adapter *adap,
                                                     struct pmac_i2c_bus *bus)
 {
         struct i2c_client *newdev;
         struct device_node *node;
+        bool found_onyx = 0;
+
+        /*
+         * In some cases we end up with the via-pmu node itself, in this
+         * case we skip this function completely as the device-tree will
+         * not contain anything useful.
+         */
+        if (!strcmp(adap->dev.of_node->name, "via-pmu"))
+                return;
 
         for_each_child_of_node(adap->dev.of_node, node) {
                 struct i2c_board_info info = {};
-                struct dev_archdata dev_ad = {};
-                const __be32 *reg;
-                char tmp[16];
                 u32 addr;
-                int len;
 
                 /* Get address & channel */
-                reg = of_get_property(node, "reg", &len);
-                if (!reg || (len < sizeof(int))) {
-                        dev_err(&adap->dev, "i2c-powermac: invalid reg on %s\n",
-                                node->full_name);
+                addr = i2c_powermac_get_addr(adap, bus, node);
+                if (addr == 0xffffffff)
                         continue;
-                }
-                addr = be32_to_cpup(reg);
 
                 /* Multibus setup, check channel */
                 if (!pmac_i2c_match_adapter(node, adap))
@@ -257,27 +367,23 @@ static void __devinit i2c_powermac_register_devices(struct i2c_adapter *adap,
                 dev_dbg(&adap->dev, "i2c-powermac: register %s\n",
                         node->full_name);
 
-                /* Make up a modalias. Note: we to _NOT_ want the standard
-                 * i2c drivers to match with any of our powermac stuff
-                 * unless they have been specifically modified to handle
-                 * it on a case by case basis. For example, for thermal
-                 * control, things like lm75 etc... shall match with their
-                 * corresponding windfarm drivers, _NOT_ the generic ones,
-                 * so we force a prefix of AAPL, onto the modalias to
-                 * make that happen
+                /*
+                 * Keep track of some device existence to handle
+                 * workarounds later.
                  */
-                if (of_modalias_node(node, tmp, sizeof(tmp)) < 0) {
-                        dev_err(&adap->dev, "i2c-powermac: modalias failure"
-                                " on %s\n", node->full_name);
+                if (of_device_is_compatible(node, "pcm3052"))
+                        found_onyx = true;
+
+                /* Make up a modalias */
+                if (!i2c_powermac_get_type(adap, node, addr,
+                                           info.type, sizeof(info.type))) {
                         continue;
                 }
-                snprintf(info.type, sizeof(info.type), "MAC,%s", tmp);
 
                 /* Fill out the rest of the info structure */
-                info.addr = (addr & 0xff) >> 1;
+                info.addr = addr;
                 info.irq = irq_of_parse_and_map(node, 0);
                 info.of_node = of_node_get(node);
-                info.archdata = &dev_ad;
 
                 newdev = i2c_new_device(adap, &info);
                 if (!newdev) {
@@ -292,6 +398,9 @@ static void __devinit i2c_powermac_register_devices(struct i2c_adapter *adap,
                         continue;
                 }
         }
+
+        /* Additional workarounds */
+        i2c_powermac_add_missing(adap, bus, found_onyx);
 }
 
 static int __devinit i2c_powermac_probe(struct platform_device *dev)