On Mon, 15 Apr 2019 20:46:41 +0200 Vitor Soares vitor.soares@synopsys.com wrote:
Currently in case of mixed slow bus topologie and all i2c devices support FM+ speed, the i3c subsystem limite the SCL to FM speed.
" 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. "
Also in case on mixed slow bus mode the max speed for both i2c or i3c transfers is FM or FM+.
Looks like you're basically repeating what you said above.
This patch fix the definition of i2c and i3c scl rate based on bus
^fixes on the bus
topologie and LVR[4] if no user input.
^topology ^if the rate is not already specified by the user.
In case of mixed slow mode the i3c scl rate is overridden.
^ with the max I2C rate.
Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Signed-off-by: Vitor Soares vitor.soares@synopsys.com Cc: Boris Brezillon bbrezillon@kernel.org Cc: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org
drivers/i3c/master.c | 39 +++++++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 14 deletions(-)
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 909c2ad..1c4a86a 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -564,20 +564,30 @@ 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 i2c_scl_rate)
Can we rename the last arg into max_i2c_scl_rate?
{ i3cbus->mode = mode;
- if (!i3cbus->scl_rate.i3c)
i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;- if (!i3cbus->scl_rate.i2c) {
if (i3cbus->mode == I3C_BUS_MODE_MIXED_SLOW)i3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_SCL_RATE;elsei3cbus->scl_rate.i2c = I3C_BUS_I2C_FM_PLUS_SCL_RATE;
- switch (i3cbus->mode) {
- case I3C_BUS_MODE_PURE:
if (!i3cbus->scl_rate.i3c)i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;break;- case I3C_BUS_MODE_MIXED_FAST:
if (!i3cbus->scl_rate.i3c)i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE;if (!i3cbus->scl_rate.i2c)i3cbus->scl_rate.i2c = i2c_scl_rate;break;- case I3C_BUS_MODE_MIXED_SLOW:
if (!i3cbus->scl_rate.i2c)i3cbus->scl_rate.i2c = i2c_scl_rate;i3cbus->scl_rate.i3c = i3cbus->scl_rate.i2c;
Maybe we should do
if (!i3cbus->scl_rate.i3c || i3cbus->scl_rate.i3c > i3cbus->scl_rate.i2c) i3cbus->scl_rate.i3c = i3cbus->scl_rate.i2c; Just in case the I3C rate forced by the user is lower than the max I2C rate.
The patch looks good otherwise.
break;- default:
return -EINVAL;
- /*
- I3C/I2C frequency may have been overridden, check that user-provided
- values are not exceeding max possible frequency.
@@ -1980,9 +1990,6 @@ 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); of_node_get(node);
@@ -2432,6 +2439,7 @@ 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;
@@ -2481,9 +2489,12 @@ 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;