On 2/8/22 19:34, Potin Lai wrote:
Guenter Roeck 於 2022/2/8 下午 11:22 寫道:
On 2/8/22 03:22, Potin Lai wrote:
Add support for passing supported PD rev to TCPM.
If "supported-pd-rev" property exist, then return supported_pd_rev as
defined value in DTS, otherwise return PD_MAX_REV
Example of DTS:
fusb302: typec-portc@22 {
compatible = "fcs,fusb302";
reg = <0x22>;
...
supported-pd-rev=<1>; // PD_REV20
...
};
The new property needs to be documented. However, I am not entirely sure
I understand why it is needed. Wouldn't the supported PD revision
be a chip (fusb302) specific constant ? If so, why does it need a
devicetree property ? I think that needs some additional explanation.
Thanks,
Guenter
My initially intend was adding flexibility for developer to decided which PD revision
they want to use for negotiation.
I may be missing something, but I don't think that "flexibility for developer
to decide which PD revision they want to use for negotiation" is entirely appropriate.
This should be a chip property, not something a developer should decide. As written,
the code does accept PC version 3 for FUSB302 by default, which seems odd and unusual.
If the chip supports PD version 3, why artificially limit it to earlier PD revisions ?
I think this requires a detailed description of the use case. Is fusb302 indeed not able
to support a specific version of the power delivery specification ? If yes,
what is the limitation, and why would it need to be configurable with a devicetree
property ?
Thanks,
Guenter
I saw your reply in another patch, I agree with you, it will be simple and consistent if
move "supported-pd-rev" to tcpm fwnode as other capabilities.
Just want to double confirm, is "usb-connector.yaml" right place to put documentation
if adding "supported-pd-rev" in fwnode?
Thanks,
Potin
Signed-off-by: Potin Lai <potin.lai@xxxxxxxxxxxx>
---
drivers/usb/typec/tcpm/fusb302.c | 20 ++++++++++++++++++++
1 file changed, 20 insertions(+)
diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c
index 72f9001b0792..8cff92d58b96 100644
--- a/drivers/usb/typec/tcpm/fusb302.c
+++ b/drivers/usb/typec/tcpm/fusb302.c
@@ -109,6 +109,9 @@ struct fusb302_chip {
enum typec_cc_status cc2;
u32 snk_pdo[PDO_MAX_OBJECTS];
+ /* supported pd rev */
+ u32 supported_pd_rev;
+
#ifdef CONFIG_DEBUG_FS
struct dentry *dentry;
/* lock for log buffer access */
@@ -1056,6 +1059,13 @@ static int tcpm_pd_transmit(struct tcpc_dev *dev, enum tcpm_transmit_type type,
return ret;
}
+static u32 tcpm_supported_pd_rev(struct tcpc_dev *dev)
+{
+ struct fusb302_chip *chip = container_of(dev, struct fusb302_chip,
+ tcpc_dev);
+ return chip->supported_pd_rev;
+}
+
static enum typec_cc_status fusb302_bc_lvl_to_cc(u8 bc_lvl)
{
if (bc_lvl == FUSB_REG_STATUS0_BC_LVL_1230_MAX)
@@ -1129,6 +1139,7 @@ static void init_tcpc_dev(struct tcpc_dev *fusb302_tcpc_dev)
fusb302_tcpc_dev->set_roles = tcpm_set_roles;
fusb302_tcpc_dev->start_toggling = tcpm_start_toggling;
fusb302_tcpc_dev->pd_transmit = tcpm_pd_transmit;
+ fusb302_tcpc_dev->supported_pd_rev = tcpm_supported_pd_rev;
}
static const char * const cc_polarity_name[] = {
@@ -1683,6 +1694,7 @@ static int fusb302_probe(struct i2c_client *client,
struct fusb302_chip *chip;
struct i2c_adapter *adapter = client->adapter;
struct device *dev = &client->dev;
+ struct device_node *np = dev->of_node;
const char *name;
int ret = 0;
@@ -1756,6 +1768,14 @@ static int fusb302_probe(struct i2c_client *client,
dev_err(dev, "cannot request IRQ for GPIO Int_N, ret=%d", ret);
goto tcpm_unregister_port;
}
+
+ if (of_property_read_u32(np, "supported-pd-rev",
+ &chip->supported_pd_rev) < 0) {
+ chip->supported_pd_rev = PD_MAX_REV;
+ } else if (chip->supported_pd_rev > PD_MAX_REV) {
+ chip->supported_pd_rev = PD_MAX_REV;
+ }
The else part is also checked in the tcpm code and thus seems
to be redundant.
+
enable_irq_wake(chip->gpio_int_n_irq);
i2c_set_clientdata(client, chip);
