Commit 34a08176 authored by Alex Elder's avatar Alex Elder Committed by Jakub Kicinski
Browse files

net: ipa: request IPA register values be retained 



In some cases, the IPA hardware needs to request the always-on
subsystem (AOSS) to coordinate with the IPA microcontroller to
retain IPA register values at power collapse.  This is done by
issuing a QMP request to the AOSS microcontroller.  A similar
request ondoes that request.

We must get and hold the "QMP" handle early, because we might get
back EPROBE_DEFER for that.  But the actual request should be sent
while we know the IPA clock is active, and when we know the
microcontroller is operational.

Fixes: 1aac309d ("net: ipa: use autosuspend")
Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent ac62a017

drivers/net/ipa/ipa_power.c

+52 −0
Original line number Diff line number Diff line
@@ -11,6 +11,8 @@ 
#include <linux/pm_runtime.h>

#include <linux/bitops.h>



#include "linux/soc/qcom/qcom_aoss.h"



#include "ipa.h"

#include "ipa_power.h"

#include "ipa_endpoint.h"
@@ -64,6 +66,7 @@ enum ipa_power_flag { 
 * struct ipa_power - IPA power management information

 * @dev:		IPA device pointer

 * @core:		IPA core clock

 * @qmp:		QMP handle for AOSS communication

 * @spinlock:		Protects modem TX queue enable/disable

 * @flags:		Boolean state flags

 * @interconnect_count:	Number of elements in interconnect[]
@@ -72,6 +75,7 @@ enum ipa_power_flag { 
struct ipa_power {

	struct device *dev;

	struct clk *core;

	struct qmp *qmp;

	spinlock_t spinlock;	/* used with STOPPED/STARTED power flags */

	DECLARE_BITMAP(flags, IPA_POWER_FLAG_COUNT);

	u32 interconnect_count;
@@ -382,6 +386,47 @@ void ipa_power_modem_queue_active(struct ipa *ipa) 
	clear_bit(IPA_POWER_FLAG_STARTED, ipa->power->flags);

}



static int ipa_power_retention_init(struct ipa_power *power)

{

	struct qmp *qmp = qmp_get(power->dev);



	if (IS_ERR(qmp)) {

		if (PTR_ERR(qmp) == -EPROBE_DEFER)

			return -EPROBE_DEFER;



		/* We assume any other error means it's not defined/needed */

		qmp = NULL;

	}

	power->qmp = qmp;



	return 0;

}



static void ipa_power_retention_exit(struct ipa_power *power)

{

	qmp_put(power->qmp);

	power->qmp = NULL;

}



/* Control register retention on power collapse */

void ipa_power_retention(struct ipa *ipa, bool enable)

{

	static const char fmt[] = "{ class: bcm, res: ipa_pc, val: %c }";

	struct ipa_power *power = ipa->power;

	char buf[36];	/* Exactly enough for fmt[]; size a multiple of 4 */

	int ret;



	if (!power->qmp)

		return;		/* Not needed on this platform */



	(void)snprintf(buf, sizeof(buf), fmt, enable ? '1' : '0');



	ret = qmp_send(power->qmp, buf, sizeof(buf));

	if (ret)

		dev_err(power->dev, "error %d sending QMP %sable request\n",

			ret, enable ? "en" : "dis");

}



int ipa_power_setup(struct ipa *ipa)

{

	int ret;
@@ -438,12 +483,18 @@ ipa_power_init(struct device *dev, const struct ipa_power_data *data) 
	if (ret)

		goto err_kfree;



	ret = ipa_power_retention_init(power);

	if (ret)

		goto err_interconnect_exit;



	pm_runtime_set_autosuspend_delay(dev, IPA_AUTOSUSPEND_DELAY);

	pm_runtime_use_autosuspend(dev);

	pm_runtime_enable(dev);



	return power;



err_interconnect_exit:

	ipa_interconnect_exit(power);

err_kfree:

	kfree(power);

err_clk_put:
@@ -460,6 +511,7 @@ void ipa_power_exit(struct ipa_power *power) 


	pm_runtime_disable(dev);

	pm_runtime_dont_use_autosuspend(dev);

	ipa_power_retention_exit(power);

	ipa_interconnect_exit(power);

	kfree(power);

	clk_put(clk);

drivers/net/ipa/ipa_power.h

+7 −0
Original line number Diff line number Diff line
@@ -40,6 +40,13 @@ void ipa_power_modem_queue_wake(struct ipa *ipa); 
 */

void ipa_power_modem_queue_active(struct ipa *ipa);



/**

 * ipa_power_retention() - Control register retention on power collapse

 * @ipa:	IPA pointer

 * @enable:	Whether retention should be enabled or disabled

 */

void ipa_power_retention(struct ipa *ipa, bool enable);



/**

 * ipa_power_setup() - Set up IPA power management

 * @ipa:	IPA pointer

drivers/net/ipa/ipa_uc.c

+5 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 


#include "ipa.h"

#include "ipa_uc.h"

#include "ipa_power.h"



/**

 * DOC:  The IPA embedded microcontroller
@@ -154,6 +155,7 @@ static void ipa_uc_response_hdlr(struct ipa *ipa, enum ipa_irq_id irq_id) 
	case IPA_UC_RESPONSE_INIT_COMPLETED:

		if (ipa->uc_powered) {

			ipa->uc_loaded = true;

			ipa_power_retention(ipa, true);

			pm_runtime_mark_last_busy(dev);

			(void)pm_runtime_put_autosuspend(dev);

			ipa->uc_powered = false;
@@ -184,6 +186,9 @@ void ipa_uc_deconfig(struct ipa *ipa) 


	ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_1);

	ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_UC_0);

	if (ipa->uc_loaded)

		ipa_power_retention(ipa, false);



	if (!ipa->uc_powered)

		return;