[ 241/262] i2c/powermac: Improve detection of devices from device-tree

From: Greg Kroah-Hartman
Date: Fri Sep 28 2012 - 15:06:07 EST


From: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx>

3.5-stable review patch. If anyone has any objections, please let me know.

------------------

From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>

commit 3a3dd0186f619b74e61e6f29dddcaf59af7d3cac upstream.

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@xxxxxxxxxxxxxxxxxxx>
Cc: Michel DÃnzer <michel@xxxxxxxxxxx>
Cc: Elimar Riesebieter <riesebie@xxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/i2c/busses/i2c-powermac.c | 157 ++++++++++++++++++++++++++++++++------
1 file changed, 133 insertions(+), 24 deletions(-)

--- a/drivers/i2c/busses/i2c-powermac.c
+++ b/drivers/i2c/busses/i2c-powermac.c
@@ -227,28 +227,138 @@ static int __devexit i2c_powermac_remove
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_regis
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_regis
continue;
}
}
+
+ /* Additional workarounds */
+ i2c_powermac_add_missing(adap, bus, found_onyx);
}

static int __devinit i2c_powermac_probe(struct platform_device *dev)


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