[PATCH v3 2/9] media: i2c: ds90ub960: Replace aliased clients list with bitmap

Romain Gantois
2024-11-25T08:45:34Z

The ds90ub960 driver currently uses a list of i2c_client structs to keep
track of used I2C address translator (ATR) alias slots for each RX port.

Keeping these i2c_client structs in the alias slot list isn't actually
needed, the driver only needs to know if a specific alias slot is already
in use or not.

Convert the aliased_clients list to a bitmap named "alias_use_mask". This
will allow removing the "client" parameter from the i2c-atr callbacks in a
future patch.

Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
---
drivers/media/i2c/ds90ub960.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/media/i2c/ds90ub960.c b/drivers/media/i2c/ds90ub960.c
index ffe5f25f8647624be005da33a6412da2493413b4..f86028894c78187257efc8fd70812387000796f7 100644
--- a/drivers/media/i2c/ds90ub960.c
+++ b/drivers/media/i2c/ds90ub960.c
@@ -468,7 +468,7 @@ struct ub960_rxport {
};
} eq;

- const struct i2c_client *aliased_clients[UB960_MAX_PORT_ALIASES];
+ DECLARE_BITMAP(alias_use_mask, UB960_MAX_PORT_ALIASES);
};

struct ub960_asd {
@@ -1032,17 +1032,13 @@ static int ub960_atr_attach_client(struct i2c_atr *atr, u32 chan_id,
struct device *dev = &priv->client->dev;
unsigned int reg_idx;

- for (reg_idx = 0; reg_idx < ARRAY_SIZE(rxport->aliased_clients); reg_idx++) {
- if (!rxport->aliased_clients[reg_idx])
- break;
- }
-
- if (reg_idx == ARRAY_SIZE(rxport->aliased_clients)) {
+ reg_idx = find_first_zero_bit(rxport->alias_use_mask, UB960_MAX_PORT_ALIASES);
+ if (reg_idx >= UB960_MAX_PORT_ALIASES) {
dev_err(dev, "rx%u: alias pool exhausted\n", rxport->nport);
return -EADDRNOTAVAIL;
}

- rxport->aliased_clients[reg_idx] = client;
+ set_bit(reg_idx, rxport->alias_use_mask);

ub960_rxport_write(priv, chan_id, UB960_RR_SLAVE_ID(reg_idx),
client->addr << 1);
@@ -1063,18 +1059,15 @@ static void ub960_atr_detach_client(struct i2c_atr *atr, u32 chan_id,
struct device *dev = &priv->client->dev;
unsigned int reg_idx;

- for (reg_idx = 0; reg_idx < ARRAY_SIZE(rxport->aliased_clients); reg_idx++) {
- if (rxport->aliased_clients[reg_idx] == client)
- break;
- }
+ reg_idx = find_first_zero_bit(rxport->alias_use_mask, UB960_MAX_PORT_ALIASES);

- if (reg_idx == ARRAY_SIZE(rxport->aliased_clients)) {
+ if (reg_idx >= UB960_MAX_PORT_ALIASES) {
dev_err(dev, "rx%u: client 0x%02x is not mapped!\n",
rxport->nport, client->addr);
return;
}

- rxport->aliased_clients[reg_idx] = NULL;
+ clear_bit(reg_idx, rxport->alias_use_mask);

ub960_rxport_write(priv, chan_id, UB960_RR_SLAVE_ALIAS(reg_idx), 0);

@@ -3404,6 +3397,8 @@ static int ub960_parse_dt_rxport(struct ub960_data *priv, unsigned int nport,
if (ret)
goto err_put_remote_fwnode;

+ bitmap_zero(rxport->alias_use_mask, UB960_MAX_PORT_ALIASES);
+
return 0;

err_put_remote_fwnode:

--
2.47.0