diff mbox series

[v2,1/2] usb: typec: tps6598x: add reset gpio support

Message ID 20230912-topic-tps6598x_reset-v2-1-02a12e2ec50a@wolfvision.net
State New
Headers
Series usb: typec: tps6598x: add reset gpio support |

Commit Message

Javier Carrasco Sept. 15, 2023, 12:23 p.m. UTC 
  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 <javier.carrasco@wolfvision.net>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
---
 drivers/usb/typec/tipd/core.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

Comments

Heikki Krogerus Sept. 15, 2023, 12:57 p.m. UTC | #1 
On Fri, Sep 15, 2023 at 02:23:48PM +0200, 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 <javier.carrasco@wolfvision.net>
> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
> ---
>  drivers/usb/typec/tipd/core.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
> index 37b56ce75f39..3068ef300073 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);

Do you need that "if (tps->reset)" in this case? That function is NULL safe,
right?

>  }
>  
>  static int __maybe_unused tps6598x_suspend(struct device *dev)
> @@ -902,6 +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)
> @@ -918,6 +935,9 @@ 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

thanks,
Javier Carrasco Sept. 15, 2023, 1:17 p.m. UTC | #2 
On 15.09.23 14:57, Heikki Krogerus wrote:
> On Fri, Sep 15, 2023 at 02:23:48PM +0200, 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 <javier.carrasco@wolfvision.net>
>> Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
>> ---
>>  drivers/usb/typec/tipd/core.c | 20 ++++++++++++++++++++
>>  1 file changed, 20 insertions(+)
>>
>> diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
>> index 37b56ce75f39..3068ef300073 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);
> 
> Do you need that "if (tps->reset)" in this case? That function is NULL safe,
> right?
> 
The function makes use of the VALIDATE_DESC_VOID macro to make it NULL
safe, but this macro also calls pr_warn if the descriptor is NULL and I
do not want to add warnings for an optional property that did not exist
before because it could be confusing. But if that is the desired
behavior, I will remove the checks.

>>  }
>>  
>>  static int __maybe_unused tps6598x_suspend(struct device *dev)
>> @@ -902,6 +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)
>> @@ -918,6 +935,9 @@ 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
> 
> thanks,
> 
Thanks and best regards,
Javier Carrasco
diff mbox series

Patch

diff --git a/drivers/usb/typec/tipd/core.c b/drivers/usb/typec/tipd/core.c
index 37b56ce75f39..3068ef300073 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)
@@ -902,6 +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)
@@ -918,6 +935,9 @@  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)