Commit ecc8fb54 authored by Vitor Soares's avatar Vitor Soares Committed by Boris Brezillon
Browse files

i3c: fix i2c and i3c scl rate by bus mode

Currently the I3C framework limits SCL frequency to FM speed when
dealing with a mixed slow bus, even if all I2C devices are FM+ capable.

The core was also not accounting for I3C speed limitations when
operating in mixed slow mode and was erroneously using FM+ speed as the
max I2C speed when operating in mixed fast mode.

Fixes: 3a379bbc

 ("i3c: Add core I3C infrastructure")
Signed-off-by: default avatarVitor Soares <>
Cc: Boris Brezillon <>
Cc: <>
Cc: <>
Signed-off-by: default avatarBoris Brezillon <>
parent 5e343fbb
......@@ -91,6 +91,12 @@ void i3c_bus_normaluse_unlock(struct i3c_bus *bus)
static struct i3c_master_controller *
i3c_bus_to_i3c_master(struct i3c_bus *i3cbus)
return container_of(i3cbus, struct i3c_master_controller, bus);
static struct i3c_master_controller *dev_to_i3cmaster(struct device *dev)
return container_of(dev, struct i3c_master_controller, dev);
......@@ -565,20 +571,38 @@ static const struct device_type i3c_masterdev_type = {
.groups = i3c_masterdev_groups,
int i3c_bus_set_mode(struct i3c_bus *i3cbus, enum i3c_bus_mode mode)
int i3c_bus_set_mode(struct i3c_bus *i3cbus, enum i3c_bus_mode mode,
unsigned long max_i2c_scl_rate)
i3cbus->mode = mode;
struct i3c_master_controller *master = i3c_bus_to_i3c_master(i3cbus);
if (!i3cbus->scl_rate.i3c)
i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;
i3cbus->mode = mode;
if (!i3cbus->scl_rate.i2c) {
if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW)
i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE;
i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE;
switch (i3cbus->mode) {
if (!i3cbus->scl_rate.i3c)
i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;
if (!i3cbus->scl_rate.i3c)
i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;
if (!i3cbus->scl_rate.i2c)
i3cbus->scl_rate.i2c = max_i2c_scl_rate;
if (!i3cbus->scl_rate.i2c)
i3cbus->scl_rate.i2c = max_i2c_scl_rate;
if (!i3cbus->scl_rate.i3c ||
i3cbus->scl_rate.i3c > i3cbus->scl_rate.i2c)
i3cbus->scl_rate.i3c = i3cbus->scl_rate.i2c;
return -EINVAL;
dev_dbg(&master->dev, "i2c-scl = %ld Hz i3c-scl = %ld Hz\n",
i3cbus->scl_rate.i2c, i3cbus->scl_rate.i3c);
* I3C/I2C frequency may have been overridden, check that user-provided
* values are not exceeding max possible frequency.
......@@ -1976,9 +2000,6 @@ of_i3c_master_add_i2c_boardinfo(struct i3c_master_controller *master,
/* LVR is encoded in reg[2]. */
boardinfo->lvr = reg[2];
if (boardinfo->lvr & I3C_LVR_I2C_FM_MODE)
master->bus.scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE;
list_add_tail(&boardinfo->node, &master->boardinfo.i2c);
......@@ -2424,6 +2445,7 @@ int i3c_master_register(struct i3c_master_controller *master,
const struct i3c_master_controller_ops *ops,
bool secondary)
unsigned long i2c_scl_rate = I3C_BUS_I2C_FM_PLUS_SCL_RATE;
struct i3c_bus *i3cbus = i3c_master_get_bus(master);
enum i3c_bus_mode mode = I3C_BUS_MODE_PURE;
struct i2c_dev_boardinfo *i2cbi;
......@@ -2473,9 +2495,12 @@ int i3c_master_register(struct i3c_master_controller *master,
ret = -EINVAL;
goto err_put_dev;
if (i2cbi->lvr & I3C_LVR_I2C_FM_MODE)
i2c_scl_rate = I3C_BUS_I2C_FM_SCL_RATE;
ret = i3c_bus_set_mode(i3cbus, mode);
ret = i3c_bus_set_mode(i3cbus, mode, i2c_scl_rate);
if (ret)
goto err_put_dev;
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