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: 1aac309d32 ("net: ipa: use autosuspend")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Alex Elder 2022-02-01 09:02:05 -06:00 committed by Jakub Kicinski
parent ac62a0174d
commit 34a081761e
3 changed files with 64 additions and 0 deletions

View File

@ -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);

View File

@ -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

View File

@ -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;