Revert "i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED"

This reverts commit 432b688424 which is
commit 2f552fa280590e61bd3dbe66a7b54b99caa642a4 upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I81c1f29aa2ad7e5776c8c7dfd9257d866b943d54
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/i3c/master.c

@@ -341,7 +341,7 @@ struct bus_type i3c_bus_type = {
 };
 
 static enum i3c_addr_slot_status
-i3c_bus_get_addr_slot_status_mask(struct i3c_bus *bus, u16 addr, u32 mask)
+i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
 {
 	unsigned long status;
 	int bitpos = addr * I3C_ADDR_SLOT_STATUS_BITS;
@@ -352,17 +352,11 @@ i3c_bus_get_addr_slot_status_mask(struct i3c_bus *bus, u16 addr, u32 mask)
 	status = bus->addrslots[bitpos / BITS_PER_LONG];
 	status >>= bitpos % BITS_PER_LONG;
 
-	return status & mask;
+	return status & I3C_ADDR_SLOT_STATUS_MASK;
 }
 
-static enum i3c_addr_slot_status
+static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
-i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
+					 enum i3c_addr_slot_status status)
-{
-	return i3c_bus_get_addr_slot_status_mask(bus, addr, I3C_ADDR_SLOT_STATUS_MASK);
-}
-
-static void i3c_bus_set_addr_slot_status_mask(struct i3c_bus *bus, u16 addr,
-					      enum i3c_addr_slot_status status, u32 mask)
 {
 	int bitpos = addr * I3C_ADDR_SLOT_STATUS_BITS;
 	unsigned long *ptr;
@@ -371,14 +365,9 @@ static void i3c_bus_set_addr_slot_status_mask(struct i3c_bus *bus, u16 addr,
 		return;
 
 	ptr = bus->addrslots + (bitpos / BITS_PER_LONG);
-	*ptr &= ~((unsigned long)mask << (bitpos % BITS_PER_LONG));
+	*ptr &= ~((unsigned long)I3C_ADDR_SLOT_STATUS_MASK <<
-	*ptr |= ((unsigned long)status & mask) << (bitpos % BITS_PER_LONG);
+						(bitpos % BITS_PER_LONG));
-}
+	*ptr |= (unsigned long)status << (bitpos % BITS_PER_LONG);
-
-static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
-					 enum i3c_addr_slot_status status)
-{
-	i3c_bus_set_addr_slot_status_mask(bus, addr, status, I3C_ADDR_SLOT_STATUS_MASK);
 }
 
 static bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr)
@@ -390,44 +379,13 @@ static bool i3c_bus_dev_addr_is_avail(struct i3c_bus *bus, u8 addr)
 	return status == I3C_ADDR_SLOT_FREE;
 }
 
-/*
- * ┌────┬─────────────┬───┬─────────┬───┐
- * │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA  │ T ├────┐
- * └────┴─────────────┴───┴─────────┴───┘    │
- * ┌─────────────────────────────────────────┘
- * │  ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐
- * └─►│Sr│7'h7E RnW=1  │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│
- *    └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘
- * Some master controllers (such as HCI) need to prepare the entire above transaction before
- * sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated
- * before knowing the target device's UID information.
- *
- * However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is
- * typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI
- * priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is
- * not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with
- * the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise,
- * if the "init_dyn_addr" is already in use by another I3C device, the target device will not be
- * able to switch to its desired address.
- *
- * If the previous step fails, fallback returning one of the remaining unassigned address,
- * regardless of its state in the desired list.
- */
 static int i3c_bus_get_free_addr(struct i3c_bus *bus, u8 start_addr)
 {
 	enum i3c_addr_slot_status status;
 	u8 addr;
 
 	for (addr = start_addr; addr < I3C_MAX_ADDR; addr++) {
-		status = i3c_bus_get_addr_slot_status_mask(bus, addr,
+		status = i3c_bus_get_addr_slot_status(bus, addr);
-							   I3C_ADDR_SLOT_EXT_STATUS_MASK);
-		if (status == I3C_ADDR_SLOT_FREE)
-			return addr;
-	}
-
-	for (addr = start_addr; addr < I3C_MAX_ADDR; addr++) {
-		status = i3c_bus_get_addr_slot_status_mask(bus, addr,
-							   I3C_ADDR_SLOT_STATUS_MASK);
 		if (status == I3C_ADDR_SLOT_FREE)
 			return addr;
 	}
@@ -1902,10 +1860,9 @@ static int i3c_master_bus_init(struct i3c_master_controller *master)
 			goto err_rstdaa;
 		}
 
-		i3c_bus_set_addr_slot_status_mask(&master->bus,
+		i3c_bus_set_addr_slot_status(&master->bus,
-						  i3cboardinfo->init_dyn_addr,
+					     i3cboardinfo->init_dyn_addr,
-						  I3C_ADDR_SLOT_I3C_DEV | I3C_ADDR_SLOT_EXT_DESIRED,
+					     I3C_ADDR_SLOT_I3C_DEV);
-						  I3C_ADDR_SLOT_EXT_STATUS_MASK);
 
 		/*
 		 * Only try to create/attach devices that have a static

include/linux/i3c/master.h

@@ -289,8 +289,7 @@ enum i3c_open_drain_speed {
  * @I3C_ADDR_SLOT_I2C_DEV: address is assigned to an I2C device
  * @I3C_ADDR_SLOT_I3C_DEV: address is assigned to an I3C device
  * @I3C_ADDR_SLOT_STATUS_MASK: address slot mask
- * @I3C_ADDR_SLOT_EXT_DESIRED: the bitmask represents addresses that are preferred by some devices,
+ *
- *			       such as the "assigned-address" property in a device tree source.
  * On an I3C bus, addresses are assigned dynamically, and we need to know which
  * addresses are free to use and which ones are already assigned.
  *
@@ -303,11 +302,9 @@ enum i3c_addr_slot_status {
 	I3C_ADDR_SLOT_I2C_DEV,
 	I3C_ADDR_SLOT_I3C_DEV,
 	I3C_ADDR_SLOT_STATUS_MASK = 3,
-	I3C_ADDR_SLOT_EXT_STATUS_MASK = 7,
-	I3C_ADDR_SLOT_EXT_DESIRED = BIT(2),
 };
 
-#define I3C_ADDR_SLOT_STATUS_BITS 4
+#define I3C_ADDR_SLOT_STATUS_BITS 2
 
 /**
  * struct i3c_bus - I3C bus object