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// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
* Copyright (C) 2018-2021 Linaro Ltd.
*/
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/interconnect.h>
#include <linux/pm.h>
#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"
#include "ipa_modem.h"
#include "ipa_data.h"
/**
* DOC: IPA Power Management
*
* The IPA hardware is enabled when the IPA core clock and all the
* interconnects (buses) it depends on are enabled. Runtime power
* management is used to determine whether the core clock and
* interconnects are enabled, and if not in use to be suspended
* automatically.
*
* The core clock currently runs at a fixed clock rate when enabled,
* an all interconnects use a fixed average and peak bandwidth.
*/
#define IPA_AUTOSUSPEND_DELAY 500 /* milliseconds */
/**
* struct ipa_interconnect - IPA interconnect information
* @path: Interconnect path
* @average_bandwidth: Average interconnect bandwidth (KB/second)
* @peak_bandwidth: Peak interconnect bandwidth (KB/second)
*/
struct ipa_interconnect {
struct icc_path *path;
u32 average_bandwidth;
u32 peak_bandwidth;
};
/**
* enum ipa_power_flag - IPA power flags
* @IPA_POWER_FLAG_RESUMED: Whether resume from suspend has been signaled
* @IPA_POWER_FLAG_SYSTEM: Hardware is system (not runtime) suspended
* @IPA_POWER_FLAG_STOPPED: Modem TX is disabled by ipa_start_xmit()
* @IPA_POWER_FLAG_STARTED: Modem TX was enabled by ipa_runtime_resume()
* @IPA_POWER_FLAG_COUNT: Number of defined power flags
*/
enum ipa_power_flag {
IPA_POWER_FLAG_RESUMED,
IPA_POWER_FLAG_SYSTEM,
IPA_POWER_FLAG_STOPPED,
IPA_POWER_FLAG_STARTED,
IPA_POWER_FLAG_COUNT, /* Last; not a 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[]
* @interconnect: Interconnect array
*/
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;
struct ipa_interconnect *interconnect;
};
static int ipa_interconnect_init_one(struct device *dev,
struct ipa_interconnect *interconnect,
const struct ipa_interconnect_data *data)
{
struct icc_path *path;
path = of_icc_get(dev, data->name);
if (IS_ERR(path)) {
int ret = PTR_ERR(path);
dev_err_probe(dev, ret, "error getting %s interconnect\n",
data->name);
return ret;
}
interconnect->path = path;
interconnect->average_bandwidth = data->average_bandwidth;
interconnect->peak_bandwidth = data->peak_bandwidth;
return 0;
}
static void ipa_interconnect_exit_one(struct ipa_interconnect *interconnect)
{
icc_put(interconnect->path);
memset(interconnect, 0, sizeof(*interconnect));
}
/* Initialize interconnects required for IPA operation */
static int ipa_interconnect_init(struct ipa_power *power, struct device *dev,
const struct ipa_interconnect_data *data)
{
struct ipa_interconnect *interconnect;
u32 count;
int ret;
count = power->interconnect_count;
interconnect = kcalloc(count, sizeof(*interconnect), GFP_KERNEL);
if (!interconnect)
return -ENOMEM;
power->interconnect = interconnect;
while (count--) {
ret = ipa_interconnect_init_one(dev, interconnect, data++);
if (ret)
goto out_unwind;
interconnect++;
}
return 0;
out_unwind:
while (interconnect-- > power->interconnect)
ipa_interconnect_exit_one(interconnect);
kfree(power->interconnect);
power->interconnect = NULL;
return ret;
}
/* Inverse of ipa_interconnect_init() */
static void ipa_interconnect_exit(struct ipa_power *power)
{
struct ipa_interconnect *interconnect;
interconnect = power->interconnect + power->interconnect_count;
while (interconnect-- > power->interconnect)
ipa_interconnect_exit_one(interconnect);
kfree(power->interconnect);
power->interconnect = NULL;
}
/* Currently we only use one bandwidth level, so just "enable" interconnects */
static int ipa_interconnect_enable(struct ipa *ipa)
{
struct ipa_interconnect *interconnect;
struct ipa_power *power = ipa->power;
int ret;
u32 i;
interconnect = power->interconnect;
for (i = 0; i < power->interconnect_count; i++) {
ret = icc_set_bw(interconnect->path,
interconnect->average_bandwidth,
interconnect->peak_bandwidth);
if (ret) {
dev_err(&ipa->pdev->dev,
"error %d enabling %s interconnect\n",
ret, icc_get_name(interconnect->path));
goto out_unwind;
}
interconnect++;
}
return 0;
out_unwind:
while (interconnect-- > power->interconnect)
(void)icc_set_bw(interconnect->path, 0, 0);
return ret;
}
/* To disable an interconnect, we just its bandwidth to 0 */
static int ipa_interconnect_disable(struct ipa *ipa)
{
struct ipa_interconnect *interconnect;
struct ipa_power *power = ipa->power;
struct device *dev = &ipa->pdev->dev;
int result = 0;
u32 count;
int ret;
count = power->interconnect_count;
interconnect = power->interconnect + count;
while (count--) {
interconnect--;
ret = icc_set_bw(interconnect->path, 0, 0);
if (ret) {
dev_err(dev, "error %d disabling %s interconnect\n",
ret, icc_get_name(interconnect->path));
/* Try to disable all; record only the first error */
if (!result)
result = ret;
}
}
return result;
}
/* Enable IPA power, enabling interconnects and the core clock */
static int ipa_power_enable(struct ipa *ipa)
{
int ret;
ret = ipa_interconnect_enable(ipa);
if (ret)
return ret;
ret = clk_prepare_enable(ipa->power->core);
if (ret) {
dev_err(&ipa->pdev->dev, "error %d enabling core clock\n", ret);
(void)ipa_interconnect_disable(ipa);
}
return ret;
}
/* Inverse of ipa_power_enable() */
static int ipa_power_disable(struct ipa *ipa)
{
clk_disable_unprepare(ipa->power->core);
return ipa_interconnect_disable(ipa);
}
static int ipa_runtime_suspend(struct device *dev)
{
struct ipa *ipa = dev_get_drvdata(dev);
/* Endpoints aren't usable until setup is complete */
if (ipa->setup_complete) {
__clear_bit(IPA_POWER_FLAG_RESUMED, ipa->power->flags);
ipa_endpoint_suspend(ipa);
gsi_suspend(&ipa->gsi);
}
return ipa_power_disable(ipa);
}
static int ipa_runtime_resume(struct device *dev)
{
struct ipa *ipa = dev_get_drvdata(dev);
int ret;
ret = ipa_power_enable(ipa);
if (WARN_ON(ret < 0))
return ret;
/* Endpoints aren't usable until setup is complete */
if (ipa->setup_complete) {
gsi_resume(&ipa->gsi);
ipa_endpoint_resume(ipa);
}
return 0;
}
static int ipa_suspend(struct device *dev)
{
struct ipa *ipa = dev_get_drvdata(dev);
__set_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags);
/* Increment the disable depth to ensure that the IRQ won't
* be re-enabled until the matching _enable call in
* ipa_resume(). We do this to ensure that the interrupt
* handler won't run whilst PM runtime is disabled.
*
* Note that disabling the IRQ is NOT the same as disabling
* irq wake. If wakeup is enabled for the IPA then the IRQ
* will still cause the system to wake up, see irq_set_irq_wake().
*/
ipa_interrupt_irq_disable(ipa);
return pm_runtime_force_suspend(dev);
}
static int ipa_resume(struct device *dev)
{
struct ipa *ipa = dev_get_drvdata(dev);
int ret;
ret = pm_runtime_force_resume(dev);
__clear_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags);
/* Now that PM runtime is enabled again it's safe
* to turn the IRQ back on and process any data
* that was received during suspend.
*/
ipa_interrupt_irq_enable(ipa);
return ret;
}
/* Return the current IPA core clock rate */
u32 ipa_core_clock_rate(struct ipa *ipa)
{
return ipa->power ? (u32)clk_get_rate(ipa->power->core) : 0;
}
/**
* ipa_suspend_handler() - Handle the suspend IPA interrupt
* @ipa: IPA pointer
* @irq_id: IPA interrupt type (unused)
*
* If an RX endpoint is suspended, and the IPA has a packet destined for
* that endpoint, the IPA generates a SUSPEND interrupt to inform the AP
* that it should resume the endpoint. If we get one of these interrupts
* we just wake up the system.
*/
static void ipa_suspend_handler(struct ipa *ipa, enum ipa_irq_id irq_id)
{
/* To handle an IPA interrupt we will have resumed the hardware
* just to handle the interrupt, so we're done. If we are in a
* system suspend, trigger a system resume.
*/
if (!__test_and_set_bit(IPA_POWER_FLAG_RESUMED, ipa->power->flags))
if (test_bit(IPA_POWER_FLAG_SYSTEM, ipa->power->flags))
pm_wakeup_dev_event(&ipa->pdev->dev, 0, true);
/* Acknowledge/clear the suspend interrupt on all endpoints */
ipa_interrupt_suspend_clear_all(ipa->interrupt);
}
/* The next few functions coordinate stopping and starting the modem
* network device transmit queue.
*
* Transmit can be running concurrent with power resume, and there's a
* chance the resume completes before the transmit path stops the queue,
* leaving the queue in a stopped state. The next two functions are used
* to avoid this: ipa_power_modem_queue_stop() is used by ipa_start_xmit()
* to conditionally stop the TX queue; and ipa_power_modem_queue_start()
* is used by ipa_runtime_resume() to conditionally restart it.
*
* Two flags and a spinlock are used. If the queue is stopped, the STOPPED
* power flag is set. And if the queue is started, the STARTED flag is set.
* The queue is only started on resume if the STOPPED flag is set. And the
* queue is only started in ipa_start_xmit() if the STARTED flag is *not*
* set. As a result, the queue remains operational if the two activites
* happen concurrently regardless of the order they complete. The spinlock
* ensures the flag and TX queue operations are done atomically.
*
* The first function stops the modem netdev transmit queue, but only if
* the STARTED flag is *not* set. That flag is cleared if it was set.
* If the queue is stopped, the STOPPED flag is set. This is called only
* from the power ->runtime_resume operation.
*/
void ipa_power_modem_queue_stop(struct ipa *ipa)
{
struct ipa_power *power = ipa->power;
unsigned long flags;
spin_lock_irqsave(&power->spinlock, flags);
if (!__test_and_clear_bit(IPA_POWER_FLAG_STARTED, power->flags)) {
netif_stop_queue(ipa->modem_netdev);
__set_bit(IPA_POWER_FLAG_STOPPED, power->flags);
}
spin_unlock_irqrestore(&power->spinlock, flags);
}
/* This function starts the modem netdev transmit queue, but only if the
* STOPPED flag is set. That flag is cleared if it was set. If the queue
* was restarted, the STARTED flag is set; this allows ipa_start_xmit()
* to skip stopping the queue in the event of a race.
*/
void ipa_power_modem_queue_wake(struct ipa *ipa)
{
struct ipa_power *power = ipa->power;
unsigned long flags;
spin_lock_irqsave(&power->spinlock, flags);
if (__test_and_clear_bit(IPA_POWER_FLAG_STOPPED, power->flags)) {
__set_bit(IPA_POWER_FLAG_STARTED, power->flags);
netif_wake_queue(ipa->modem_netdev);
}
spin_unlock_irqrestore(&power->spinlock, flags);
}
/* This function clears the STARTED flag once the TX queue is operating */
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;
ipa_interrupt_add(ipa->interrupt, IPA_IRQ_TX_SUSPEND,
ipa_suspend_handler);
ret = device_init_wakeup(&ipa->pdev->dev, true);
if (ret)
ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_TX_SUSPEND);
return ret;
}
void ipa_power_teardown(struct ipa *ipa)
{
(void)device_init_wakeup(&ipa->pdev->dev, false);
ipa_interrupt_remove(ipa->interrupt, IPA_IRQ_TX_SUSPEND);
}
/* Initialize IPA power management */
struct ipa_power *
ipa_power_init(struct device *dev, const struct ipa_power_data *data)
{
struct ipa_power *power;
struct clk *clk;
int ret;
clk = clk_get(dev, "core");
if (IS_ERR(clk)) {
dev_err_probe(dev, PTR_ERR(clk), "error getting core clock\n");
return ERR_CAST(clk);
}
ret = clk_set_rate(clk, data->core_clock_rate);
if (ret) {
dev_err(dev, "error %d setting core clock rate to %u\n",
ret, data->core_clock_rate);
goto err_clk_put;
}
power = kzalloc(sizeof(*power), GFP_KERNEL);
if (!power) {
ret = -ENOMEM;
goto err_clk_put;
}
power->dev = dev;
power->core = clk;
spin_lock_init(&power->spinlock);
power->interconnect_count = data->interconnect_count;
ret = ipa_interconnect_init(power, dev, data->interconnect_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:
clk_put(clk);
return ERR_PTR(ret);
}
/* Inverse of ipa_power_init() */
void ipa_power_exit(struct ipa_power *power)
{
struct device *dev = power->dev;
struct clk *clk = power->core;
pm_runtime_disable(dev);
pm_runtime_dont_use_autosuspend(dev);
ipa_power_retention_exit(power);
ipa_interconnect_exit(power);
kfree(power);
clk_put(clk);
}
const struct dev_pm_ops ipa_pm_ops = {
.suspend = ipa_suspend,
.resume = ipa_resume,
.runtime_suspend = ipa_runtime_suspend,
.runtime_resume = ipa_runtime_resume,
};