The TPS6598x PD controller provides an active-high hardware reset input
that reinitializes all device settings. If it is not grounded by
design, the driver must be able to de-assert it in order to initialize
the device.
The PD controller is not ready for registration right after the reset
de-assertion and a delay must be introduced in that case. According to
TI, the delay can reach up to 1000 ms [1], which is in line with the
experimental results obtained with a TPS65987D.
Add a GPIO descriptor for the reset signal and basic reset management
for initialization and suspend/resume.
[1] https://e2e.ti.com/support/power-management-group/power-management/
f/power-management-forum/1269856/tps65987d-tps65987d-reset-de-assert-
to-normal-operation/4809389#4809389
Signed-off-by: Javier Carrasco <[email protected]>
---
drivers/usb/typec/tipd/core.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index 37b56ce75f39..550f5913e985 100644
--- a/drivers/usb/typec/tipd/core.c
+++ b/drivers/usb/typec/tipd/core.c
@@ -8,6 +8,7 @@
#include <linux/i2c.h>
#include <linux/acpi.h>
+#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/power_supply.h>
@@ -43,6 +44,9 @@
/* TPS_REG_SYSTEM_CONF bits */
#define TPS_SYSCONF_PORTINFO(c) ((c) & 7)
+/* reset de-assertion to ready for operation */
+#define SETUP_MS 1000
+
enum {
TPS_PORTINFO_SINK,
TPS_PORTINFO_SINK_ACCESSORY,
@@ -86,6 +90,7 @@ struct tps6598x {
struct mutex lock; /* device lock */
u8 i2c_protocol:1;
+ struct gpio_desc *reset;
struct typec_port *port;
struct typec_partner *partner;
struct usb_pd_identity partner_identity;
@@ -717,6 +722,13 @@ static int tps6598x_probe(struct i2c_client *client)
mutex_init(&tps->lock);
tps->dev = &client->dev;
+ tps->reset = devm_gpiod_get_optional(tps->dev, "reset", GPIOD_OUT_LOW);
+ if (IS_ERR(tps->reset))
+ return dev_err_probe(tps->dev, PTR_ERR(tps->reset),
+ "failed to get reset GPIO\n");
+ if (tps->reset)
+ msleep(SETUP_MS);
+
tps->regmap = devm_regmap_init_i2c(client, &tps6598x_regmap_config);
if (IS_ERR(tps->regmap))
return PTR_ERR(tps->regmap);
@@ -892,6 +904,9 @@ static void tps6598x_remove(struct i2c_client *client)
tps6598x_disconnect(tps, 0);
typec_unregister_port(tps->port);
usb_role_switch_put(tps->role_sw);
+
+ if (tps->reset)
+ gpiod_set_value_cansleep(tps->reset, 1);
}
static int __maybe_unused tps6598x_suspend(struct device *dev)
@@ -902,7 +917,8 @@ static int __maybe_unused tps6598x_suspend(struct device *dev)
if (tps->wakeup) {
disable_irq(client->irq);
enable_irq_wake(client->irq);
- }
+ } else if (tps->reset)
+ gpiod_set_value_cansleep(tps->reset, 1);
if (!client->irq)
cancel_delayed_work_sync(&tps->wq_poll);
@@ -918,6 +934,9 @@ static int __maybe_unused tps6598x_resume(struct device *dev)
if (tps->wakeup) {
disable_irq_wake(client->irq);
enable_irq(client->irq);
+ } else if (tps->reset) {
+ gpiod_set_value_cansleep(tps->reset, 0);
+ msleep(SETUP_MS);
}
if (!client->irq)
--
2.39.2
On 15/09/2023 07:50, Javier Carrasco wrote:
> The TPS6598x PD controller provides an active-high hardware reset input
> that reinitializes all device settings. If it is not grounded by
> design, the driver must be able to de-assert it in order to initialize
> the device.
>
> The PD controller is not ready for registration right after the reset
> de-assertion and a delay must be introduced in that case. According to
> TI, the delay can reach up to 1000 ms [1], which is in line with the
> experimental results obtained with a TPS65987D.
>
> Add a GPIO descriptor for the reset signal and basic reset management
> for initialization and suspend/resume.
>
> [1] https://e2e.ti.com/support/power-management-group/power-management/
> f/power-management-forum/1269856/tps65987d-tps65987d-reset-de-assert-
> to-normal-operation/4809389#4809389
>
> Signed-off-by: Javier Carrasco <[email protected]>
Reviewed-by: Bryan O'Donoghue <[email protected]>
Hello Bryan,
On 15.09.23 11:52, Bryan O'Donoghue wrote:
> On 15/09/2023 07:50, Javier Carrasco wrote:
>> The TPS6598x PD controller provides an active-high hardware reset input
>> that reinitializes all device settings. If it is not grounded by
>> design, the driver must be able to de-assert it in order to initialize
>> the device.
>>
>> The PD controller is not ready for registration right after the reset
>> de-assertion and a delay must be introduced in that case. According to
>> TI, the delay can reach up to 1000 ms [1], which is in line with the
>> experimental results obtained with a TPS65987D.
>>
>> Add a GPIO descriptor for the reset signal and basic reset management
>> for initialization and suspend/resume.
>>
>> [1]
>> https://e2e.ti.com/support/power-management-group/power-management/
>> f/power-management-forum/1269856/tps65987d-tps65987d-reset-de-assert-
>> to-normal-operation/4809389#4809389
>>
>> Signed-off-by: Javier Carrasco <[email protected]>
>> ---
>> drivers/usb/typec/tipd/core.c | 21 ++++++++++++++++++++-
>> 1 file changed, 20 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/usb/typec/tipd/core.c
>> b/drivers/usb/typec/tipd/core.c
>> index 37b56ce75f39..550f5913e985 100644
>> --- a/drivers/usb/typec/tipd/core.c
>> +++ b/drivers/usb/typec/tipd/core.c
>> @@ -8,6 +8,7 @@
>> #include <linux/i2c.h>
>> #include <linux/acpi.h>
>> +#include <linux/gpio/consumer.h>
>> #include <linux/module.h>
>> #include <linux/of.h>
>> #include <linux/power_supply.h>
>> @@ -43,6 +44,9 @@
>> /* TPS_REG_SYSTEM_CONF bits */
>> #define TPS_SYSCONF_PORTINFO(c) ((c) & 7)
>> +/* reset de-assertion to ready for operation */
>> +#define SETUP_MS 1000
>> +
>> enum {
>> TPS_PORTINFO_SINK,
>> TPS_PORTINFO_SINK_ACCESSORY,
>> @@ -86,6 +90,7 @@ struct tps6598x {
>> struct mutex lock; /* device lock */
>> u8 i2c_protocol:1;
>> + struct gpio_desc *reset;
>> struct typec_port *port;
>> struct typec_partner *partner;
>> struct usb_pd_identity partner_identity;
>> @@ -717,6 +722,13 @@ static int tps6598x_probe(struct i2c_client *client)
>> mutex_init(&tps->lock);
>> tps->dev = &client->dev;
>> + tps->reset = devm_gpiod_get_optional(tps->dev, "reset",
>> GPIOD_OUT_LOW);
>> + if (IS_ERR(tps->reset))
>> + return dev_err_probe(tps->dev, PTR_ERR(tps->reset),
>> + "failed to get reset GPIO\n");
>> + if (tps->reset)
>> + msleep(SETUP_MS);
>> +
>
> This looks a bit odd to me, shouldn't you drive reset to zero ?
>
> if (tps->reset) {
> gpiod_set_value_cansleep(tps->reset, 0);
> msleep(SETUP_MS);
> }
>
The reset line is driven to zero by means fo the GPIOD_OUT_LOW flag, so
there is no need to set it explicitly again.
> also wouldn't it make sense to functionally decompose that and reuse in
> probe() and tps6598x_resume() ?
>
> tps6598x_reset() {
> if (tps->reset) {
> gpiod_set_value_cansleep(tps->reset, 0);
> msleep(SETUP_MS);
> }
> }
>
I can move the reset action to a separate function as you proposed, but
then I suppose it would make sense to use the same function for both
reset levels. Maybe something like:
tps6598x_reset(bool level) {
if (tps->reset) {
gpiod_set_value_cansleep(tps->reset, level);
if (!level)
msleep(SETUP_MS);
}
}
> ---
> bod
Thanks for your feedback.
Best regards,
Javier Carrasco
On 15/09/2023 07:50, Javier Carrasco wrote:
> The TPS6598x PD controller provides an active-high hardware reset input
> that reinitializes all device settings. If it is not grounded by
> design, the driver must be able to de-assert it in order to initialize
> the device.
>
> The PD controller is not ready for registration right after the reset
> de-assertion and a delay must be introduced in that case. According to
> TI, the delay can reach up to 1000 ms [1], which is in line with the
> experimental results obtained with a TPS65987D.
>
> Add a GPIO descriptor for the reset signal and basic reset management
> for initialization and suspend/resume.
>
> [1] https://e2e.ti.com/support/power-management-group/power-management/
> f/power-management-forum/1269856/tps65987d-tps65987d-reset-de-assert-
> to-normal-operation/4809389#4809389
>
> Signed-off-by: Javier Carrasco <[email protected]>
> ---
> drivers/usb/typec/tipd/core.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 37b56ce75f39..550f5913e985 100644
> --- a/drivers/usb/typec/tipd/core.c
> +++ b/drivers/usb/typec/tipd/core.c
> @@ -8,6 +8,7 @@
>
> #include <linux/i2c.h>
> #include <linux/acpi.h>
> +#include <linux/gpio/consumer.h>
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/power_supply.h>
> @@ -43,6 +44,9 @@
> /* TPS_REG_SYSTEM_CONF bits */
> #define TPS_SYSCONF_PORTINFO(c) ((c) & 7)
>
> +/* reset de-assertion to ready for operation */
> +#define SETUP_MS 1000
> +
> enum {
> TPS_PORTINFO_SINK,
> TPS_PORTINFO_SINK_ACCESSORY,
> @@ -86,6 +90,7 @@ struct tps6598x {
> struct mutex lock; /* device lock */
> u8 i2c_protocol:1;
>
> + struct gpio_desc *reset;
> struct typec_port *port;
> struct typec_partner *partner;
> struct usb_pd_identity partner_identity;
> @@ -717,6 +722,13 @@ static int tps6598x_probe(struct i2c_client *client)
> mutex_init(&tps->lock);
> tps->dev = &client->dev;
>
> + tps->reset = devm_gpiod_get_optional(tps->dev, "reset", GPIOD_OUT_LOW);
> + if (IS_ERR(tps->reset))
> + return dev_err_probe(tps->dev, PTR_ERR(tps->reset),
> + "failed to get reset GPIO\n");
> + if (tps->reset)
> + msleep(SETUP_MS);
> +
This looks a bit odd to me, shouldn't you drive reset to zero ?
if (tps->reset) {
gpiod_set_value_cansleep(tps->reset, 0);
msleep(SETUP_MS);
}
also wouldn't it make sense to functionally decompose that and reuse in
probe() and tps6598x_resume() ?
tps6598x_reset() {
if (tps->reset) {
gpiod_set_value_cansleep(tps->reset, 0);
msleep(SETUP_MS);
}
}
---
bod
On 15/09/2023 11:52, Bryan O'Donoghue wrote:
>> + struct gpio_desc *reset;
>> struct typec_port *port;
>> struct typec_partner *partner;
>> struct usb_pd_identity partner_identity;
>> @@ -717,6 +722,13 @@ static int tps6598x_probe(struct i2c_client *client)
>> mutex_init(&tps->lock);
>> tps->dev = &client->dev;
>>
>> + tps->reset = devm_gpiod_get_optional(tps->dev, "reset", GPIOD_OUT_LOW);
>> + if (IS_ERR(tps->reset))
>> + return dev_err_probe(tps->dev, PTR_ERR(tps->reset),
>> + "failed to get reset GPIO\n");
>> + if (tps->reset)
>> + msleep(SETUP_MS);
>> +
>
> This looks a bit odd to me, shouldn't you drive reset to zero ?
>
> if (tps->reset) {
> gpiod_set_value_cansleep(tps->reset, 0);
It is driven by GPIOD_OUT_LOW.
> msleep(SETUP_MS);
> }
>
> also wouldn't it make sense to functionally decompose that and reuse in
> probe() and tps6598x_resume() ?
>
> tps6598x_reset() {
> if (tps->reset) {
> gpiod_set_value_cansleep(tps->reset, 0);
> msleep(SETUP_MS);
> }
> }
Best regards,
Krzysztof