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

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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>
This commit is contained in:
Greg Kroah-Hartman
2024-12-30 10:39:26 +00:00
parent 77e519c5be
commit fc7774be6b
2 changed files with 13 additions and 59 deletions
Download Patch File Download Diff File Expand all files Collapse all files

65
drivers/i3c/master.c
View File

@@ -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
i3c_bus_get_addr_slot_status(struct i3c_bus *bus, u16 addr)
{
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)
static void i3c_bus_set_addr_slot_status(struct i3c_bus *bus, u16 addr,
enum i3c_addr_slot_status status)
{
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)status & mask) << (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);
*ptr &= ~((unsigned long)I3C_ADDR_SLOT_STATUS_MASK <<
(bitpos % BITS_PER_LONG));
*ptr |= (unsigned long)status << (bitpos % BITS_PER_LONG);
}
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,
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);
status = i3c_bus_get_addr_slot_status(bus, addr);
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,
i3cboardinfo->init_dyn_addr,
I3C_ADDR_SLOT_I3C_DEV | I3C_ADDR_SLOT_EXT_DESIRED,
I3C_ADDR_SLOT_EXT_STATUS_MASK);
i3c_bus_set_addr_slot_status(&master->bus,
i3cboardinfo->init_dyn_addr,
I3C_ADDR_SLOT_I3C_DEV);
/*
* Only try to create/attach devices that have a static

7
include/linux/i3c/master.h
View File

@@ -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