arche-platform.c
// SPDX-License-Identifier: GPL-2.0
/*
* Arche Platform driver to enable Unipro link.
*
* Copyright 2014-2015 Google Inc.
* Copyright 2014-2015 Linaro Ltd.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/of_platform.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/suspend.h>
#include <linux/time.h>
#include <linux/greybus.h>
#include "arche_platform.h"
#if IS_ENABLED(CONFIG_USB_HSIC_USB3613)
#include <linux/usb/usb3613.h>
#else
static inline int usb3613_hub_mode_ctrl(bool unused)
{
return 0;
}
#endif
#define WD_COLDBOOT_PULSE_WIDTH_MS 30
enum svc_wakedetect_state {
WD_STATE_IDLE, /* Default state = pulled high/low */
WD_STATE_BOOT_INIT, /* WD = falling edge (low) */
WD_STATE_COLDBOOT_TRIG, /* WD = rising edge (high), > 30msec */
WD_STATE_STANDBYBOOT_TRIG, /* As of now not used ?? */
WD_STATE_COLDBOOT_START, /* Cold boot process started */
WD_STATE_STANDBYBOOT_START, /* Not used */
};
struct arche_platform_drvdata {
/* Control GPIO signals to and from AP <=> SVC */
struct gpio_desc *svc_reset;
bool is_reset_act_hi;
struct gpio_desc *svc_sysboot;
struct gpio_desc *wake_detect; /* bi-dir,maps to WAKE_MOD & WAKE_FRAME signals */
enum arche_platform_state state;
struct gpio_desc *svc_refclk_req;
struct clk *svc_ref_clk;
struct pinctrl *pinctrl;
struct pinctrl_state *pin_default;
int num_apbs;
enum svc_wakedetect_state wake_detect_state;
int wake_detect_irq;
spinlock_t wake_lock; /* Protect wake_detect_state */
struct mutex platform_state_mutex; /* Protect state */
unsigned long wake_detect_start;
struct notifier_block pm_notifier;
struct device *dev;
};
/* Requires calling context to hold arche_pdata->platform_state_mutex */
static void arche_platform_set_state(struct arche_platform_drvdata *arche_pdata,
enum arche_platform_state state)
{
arche_pdata->state = state;
}
/* Requires arche_pdata->wake_lock is held by calling context */
static void arche_platform_set_wake_detect_state(struct arche_platform_drvdata *arche_pdata,
enum svc_wakedetect_state state)
{
arche_pdata->wake_detect_state = state;
}
static inline void svc_reset_onoff(struct gpio_desc *gpio, bool onoff)
{
gpiod_set_raw_value(gpio, onoff);
}
static int apb_cold_boot(struct device *dev, void *data)
{
int ret;
ret = apb_ctrl_coldboot(dev);
if (ret)
dev_warn(dev, "failed to coldboot\n");
/*Child nodes are independent, so do not exit coldboot operation */
return 0;
}
static int apb_poweroff(struct device *dev, void *data)
{
apb_ctrl_poweroff(dev);
/* Enable HUB3613 into HUB mode. */
if (usb3613_hub_mode_ctrl(false))
dev_warn(dev, "failed to control hub device\n");
return 0;
}
static void arche_platform_wd_irq_en(struct arche_platform_drvdata *arche_pdata)
{
/* Enable interrupt here, to read event back from SVC */
enable_irq(arche_pdata->wake_detect_irq);
}
static irqreturn_t arche_platform_wd_irq_thread(int irq, void *devid)
{
struct arche_platform_drvdata *arche_pdata = devid;
unsigned long flags;
spin_lock_irqsave(&arche_pdata->wake_lock, flags);
if (arche_pdata->wake_detect_state != WD_STATE_COLDBOOT_TRIG) {
/* Something is wrong */
spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
return IRQ_HANDLED;
}
arche_platform_set_wake_detect_state(arche_pdata,
WD_STATE_COLDBOOT_START);
spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
/* It should complete power cycle, so first make sure it is poweroff */
device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
/* Bring APB out of reset: cold boot sequence */
device_for_each_child(arche_pdata->dev, NULL, apb_cold_boot);
/* Enable HUB3613 into HUB mode. */
if (usb3613_hub_mode_ctrl(true))
dev_warn(arche_pdata->dev, "failed to control hub device\n");
spin_lock_irqsave(&arche_pdata->wake_lock, flags);
arche_platform_set_wake_detect_state(arche_pdata, WD_STATE_IDLE);
spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
return IRQ_HANDLED;
}
static irqreturn_t arche_platform_wd_irq(int irq, void *devid)
{
struct arche_platform_drvdata *arche_pdata = devid;
unsigned long flags;
spin_lock_irqsave(&arche_pdata->wake_lock, flags);
if (gpiod_get_value(arche_pdata->wake_detect)) {
/* wake/detect rising */
/*
* If wake/detect line goes high after low, within less than
* 30msec, then standby boot sequence is initiated, which is not
* supported/implemented as of now. So ignore it.
*/
if (arche_pdata->wake_detect_state == WD_STATE_BOOT_INIT) {
if (time_before(jiffies,
arche_pdata->wake_detect_start +
msecs_to_jiffies(WD_COLDBOOT_PULSE_WIDTH_MS))) {
arche_platform_set_wake_detect_state(arche_pdata,
WD_STATE_IDLE);
} else {
/*
* Check we are not in middle of irq thread
* already
*/
if (arche_pdata->wake_detect_state !=
WD_STATE_COLDBOOT_START) {
arche_platform_set_wake_detect_state(arche_pdata,
WD_STATE_COLDBOOT_TRIG);
spin_unlock_irqrestore(&arche_pdata->wake_lock,
flags);
return IRQ_WAKE_THREAD;
}
}
}
} else {
/* wake/detect falling */
if (arche_pdata->wake_detect_state == WD_STATE_IDLE) {
arche_pdata->wake_detect_start = jiffies;
/*
* In the beginning, when wake/detect goes low
* (first time), we assume it is meant for coldboot
* and set the flag. If wake/detect line stays low
* beyond 30msec, then it is coldboot else fallback
* to standby boot.
*/
arche_platform_set_wake_detect_state(arche_pdata,
WD_STATE_BOOT_INIT);
}
}
spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
return IRQ_HANDLED;
}
/*
* Requires arche_pdata->platform_state_mutex to be held
*/
static int
arche_platform_coldboot_seq(struct arche_platform_drvdata *arche_pdata)
{
int ret;
if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
return 0;
dev_info(arche_pdata->dev, "Booting from cold boot state\n");
svc_reset_onoff(arche_pdata->svc_reset, arche_pdata->is_reset_act_hi);
gpiod_set_value(arche_pdata->svc_sysboot, 0);
usleep_range(100, 200);
ret = clk_prepare_enable(arche_pdata->svc_ref_clk);
if (ret) {
dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
ret);
return ret;
}
/* bring SVC out of reset */
svc_reset_onoff(arche_pdata->svc_reset, !arche_pdata->is_reset_act_hi);
arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_ACTIVE);
return 0;
}
/*
* Requires arche_pdata->platform_state_mutex to be held
*/
static int
arche_platform_fw_flashing_seq(struct arche_platform_drvdata *arche_pdata)
{
int ret;
if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
return 0;
dev_info(arche_pdata->dev, "Switching to FW flashing state\n");
svc_reset_onoff(arche_pdata->svc_reset, arche_pdata->is_reset_act_hi);
gpiod_set_value(arche_pdata->svc_sysboot, 1);
usleep_range(100, 200);
ret = clk_prepare_enable(arche_pdata->svc_ref_clk);
if (ret) {
dev_err(arche_pdata->dev, "failed to enable svc_ref_clk: %d\n",
ret);
return ret;
}
svc_reset_onoff(arche_pdata->svc_reset, !arche_pdata->is_reset_act_hi);
arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_FW_FLASHING);
return 0;
}
/*
* Requires arche_pdata->platform_state_mutex to be held
*/
static void
arche_platform_poweroff_seq(struct arche_platform_drvdata *arche_pdata)
{
unsigned long flags;
if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
return;
/* If in fw_flashing mode, then no need to repeate things again */
if (arche_pdata->state != ARCHE_PLATFORM_STATE_FW_FLASHING) {
disable_irq(arche_pdata->wake_detect_irq);
spin_lock_irqsave(&arche_pdata->wake_lock, flags);
arche_platform_set_wake_detect_state(arche_pdata,
WD_STATE_IDLE);
spin_unlock_irqrestore(&arche_pdata->wake_lock, flags);
}
clk_disable_unprepare(arche_pdata->svc_ref_clk);
/* As part of exit, put APB back in reset state */
svc_reset_onoff(arche_pdata->svc_reset, arche_pdata->is_reset_act_hi);
arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_OFF);
}
static ssize_t state_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct arche_platform_drvdata *arche_pdata = dev_get_drvdata(dev);
int ret = 0;
mutex_lock(&arche_pdata->platform_state_mutex);
if (sysfs_streq(buf, "off")) {
if (arche_pdata->state == ARCHE_PLATFORM_STATE_OFF)
goto exit;
/* If SVC goes down, bring down APB's as well */
device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
arche_platform_poweroff_seq(arche_pdata);
} else if (sysfs_streq(buf, "active")) {
if (arche_pdata->state == ARCHE_PLATFORM_STATE_ACTIVE)
goto exit;
/* First we want to make sure we power off everything
* and then activate back again
*/
device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
arche_platform_poweroff_seq(arche_pdata);
arche_platform_wd_irq_en(arche_pdata);
ret = arche_platform_coldboot_seq(arche_pdata);
if (ret)
goto exit;
} else if (sysfs_streq(buf, "standby")) {
if (arche_pdata->state == ARCHE_PLATFORM_STATE_STANDBY)
goto exit;
dev_warn(arche_pdata->dev, "standby state not supported\n");
} else if (sysfs_streq(buf, "fw_flashing")) {
if (arche_pdata->state == ARCHE_PLATFORM_STATE_FW_FLASHING)
goto exit;
/*
* Here we only control SVC.
*
* In case of FW_FLASHING mode we do not want to control
* APBs, as in case of V2, SPI bus is shared between both
* the APBs. So let user chose which APB he wants to flash.
*/
arche_platform_poweroff_seq(arche_pdata);
ret = arche_platform_fw_flashing_seq(arche_pdata);
if (ret)
goto exit;
} else {
dev_err(arche_pdata->dev, "unknown state\n");
ret = -EINVAL;
}
exit:
mutex_unlock(&arche_pdata->platform_state_mutex);
return ret ? ret : count;
}
static ssize_t state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct arche_platform_drvdata *arche_pdata = dev_get_drvdata(dev);
switch (arche_pdata->state) {
case ARCHE_PLATFORM_STATE_OFF:
return sprintf(buf, "off\n");
case ARCHE_PLATFORM_STATE_ACTIVE:
return sprintf(buf, "active\n");
case ARCHE_PLATFORM_STATE_STANDBY:
return sprintf(buf, "standby\n");
case ARCHE_PLATFORM_STATE_FW_FLASHING:
return sprintf(buf, "fw_flashing\n");
default:
return sprintf(buf, "unknown state\n");
}
}
static DEVICE_ATTR_RW(state);
static int arche_platform_pm_notifier(struct notifier_block *notifier,
unsigned long pm_event, void *unused)
{
struct arche_platform_drvdata *arche_pdata =
container_of(notifier, struct arche_platform_drvdata,
pm_notifier);
int ret = NOTIFY_DONE;
mutex_lock(&arche_pdata->platform_state_mutex);
switch (pm_event) {
case PM_SUSPEND_PREPARE:
if (arche_pdata->state != ARCHE_PLATFORM_STATE_ACTIVE) {
ret = NOTIFY_STOP;
break;
}
device_for_each_child(arche_pdata->dev, NULL, apb_poweroff);
arche_platform_poweroff_seq(arche_pdata);
break;
case PM_POST_SUSPEND:
if (arche_pdata->state != ARCHE_PLATFORM_STATE_OFF)
break;
arche_platform_wd_irq_en(arche_pdata);
arche_platform_coldboot_seq(arche_pdata);
break;
default:
break;
}
mutex_unlock(&arche_pdata->platform_state_mutex);
return ret;
}
static int arche_platform_probe(struct platform_device *pdev)
{
struct arche_platform_drvdata *arche_pdata;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
int ret;
unsigned int flags;
arche_pdata = devm_kzalloc(&pdev->dev, sizeof(*arche_pdata),
GFP_KERNEL);
if (!arche_pdata)
return -ENOMEM;
/* setup svc reset gpio */
arche_pdata->is_reset_act_hi = of_property_read_bool(np,
"svc,reset-active-high");
if (arche_pdata->is_reset_act_hi)
flags = GPIOD_OUT_HIGH;
else
flags = GPIOD_OUT_LOW;
arche_pdata->svc_reset = devm_gpiod_get(dev, "svc,reset", flags);
if (IS_ERR(arche_pdata->svc_reset)) {
ret = PTR_ERR(arche_pdata->svc_reset);
dev_err(dev, "failed to request svc-reset GPIO: %d\n", ret);
return ret;
}
arche_platform_set_state(arche_pdata, ARCHE_PLATFORM_STATE_OFF);
arche_pdata->svc_sysboot = devm_gpiod_get(dev, "svc,sysboot",
GPIOD_OUT_LOW);
if (IS_ERR(arche_pdata->svc_sysboot)) {
ret = PTR_ERR(arche_pdata->svc_sysboot);
dev_err(dev, "failed to request sysboot0 GPIO: %d\n", ret);
return ret;
}
/* setup the clock request gpio first */
arche_pdata->svc_refclk_req = devm_gpiod_get(dev, "svc,refclk-req",
GPIOD_IN);
if (IS_ERR(arche_pdata->svc_refclk_req)) {
ret = PTR_ERR(arche_pdata->svc_refclk_req);
dev_err(dev, "failed to request svc-clk-req GPIO: %d\n", ret);
return ret;
}
/* setup refclk2 to follow the pin */
arche_pdata->svc_ref_clk = devm_clk_get(dev, "svc_ref_clk");
if (IS_ERR(arche_pdata->svc_ref_clk)) {
ret = PTR_ERR(arche_pdata->svc_ref_clk);
dev_err(dev, "failed to get svc_ref_clk: %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, arche_pdata);
arche_pdata->num_apbs = of_get_child_count(np);
dev_dbg(dev, "Number of APB's available - %d\n", arche_pdata->num_apbs);
arche_pdata->wake_detect = devm_gpiod_get(dev, "svc,wake-detect",
GPIOD_IN);
if (IS_ERR(arche_pdata->wake_detect)) {
ret = PTR_ERR(arche_pdata->wake_detect);
dev_err(dev, "Failed requesting wake_detect GPIO: %d\n", ret);
return ret;
}
arche_platform_set_wake_detect_state(arche_pdata, WD_STATE_IDLE);
arche_pdata->dev = &pdev->dev;
spin_lock_init(&arche_pdata->wake_lock);
mutex_init(&arche_pdata->platform_state_mutex);
arche_pdata->wake_detect_irq =
gpiod_to_irq(arche_pdata->wake_detect);
ret = devm_request_threaded_irq(dev, arche_pdata->wake_detect_irq,
arche_platform_wd_irq,
arche_platform_wd_irq_thread,
IRQF_TRIGGER_FALLING |
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
dev_name(dev), arche_pdata);
if (ret) {
dev_err(dev, "failed to request wake detect IRQ %d\n", ret);
return ret;
}
disable_irq(arche_pdata->wake_detect_irq);
ret = device_create_file(dev, &dev_attr_state);
if (ret) {
dev_err(dev, "failed to create state file in sysfs\n");
return ret;
}
ret = of_platform_populate(np, NULL, NULL, dev);
if (ret) {
dev_err(dev, "failed to populate child nodes %d\n", ret);
goto err_device_remove;
}
arche_pdata->pm_notifier.notifier_call = arche_platform_pm_notifier;
ret = register_pm_notifier(&arche_pdata->pm_notifier);
if (ret) {
dev_err(dev, "failed to register pm notifier %d\n", ret);
goto err_device_remove;
}
/* Explicitly power off if requested */
if (!of_property_read_bool(pdev->dev.of_node, "arche,init-off")) {
mutex_lock(&arche_pdata->platform_state_mutex);
ret = arche_platform_coldboot_seq(arche_pdata);
if (ret) {
dev_err(dev, "Failed to cold boot svc %d\n", ret);
goto err_coldboot;
}
arche_platform_wd_irq_en(arche_pdata);
mutex_unlock(&arche_pdata->platform_state_mutex);
}
dev_info(dev, "Device registered successfully\n");
return 0;
err_coldboot:
mutex_unlock(&arche_pdata->platform_state_mutex);
err_device_remove:
device_remove_file(&pdev->dev, &dev_attr_state);
return ret;
}
static int arche_remove_child(struct device *dev, void *unused)
{
struct platform_device *pdev = to_platform_device(dev);
platform_device_unregister(pdev);
return 0;
}
static int arche_platform_remove(struct platform_device *pdev)
{
struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
unregister_pm_notifier(&arche_pdata->pm_notifier);
device_remove_file(&pdev->dev, &dev_attr_state);
device_for_each_child(&pdev->dev, NULL, arche_remove_child);
arche_platform_poweroff_seq(arche_pdata);
if (usb3613_hub_mode_ctrl(false))
dev_warn(arche_pdata->dev, "failed to control hub device\n");
/* TODO: Should we do anything more here ?? */
return 0;
}
static __maybe_unused int arche_platform_suspend(struct device *dev)
{
/*
* If timing profile premits, we may shutdown bridge
* completely
*
* TODO: sequence ??
*
* Also, need to make sure we meet precondition for unipro suspend
* Precondition: Definition ???
*/
return 0;
}
static __maybe_unused int arche_platform_resume(struct device *dev)
{
/*
* At least for ES2 we have to meet the delay requirement between
* unipro switch and AP bridge init, depending on whether bridge is in
* OFF state or standby state.
*
* Based on whether bridge is in standby or OFF state we may have to
* assert multiple signals. Please refer to WDM spec, for more info.
*
*/
return 0;
}
static void arche_platform_shutdown(struct platform_device *pdev)
{
struct arche_platform_drvdata *arche_pdata = platform_get_drvdata(pdev);
arche_platform_poweroff_seq(arche_pdata);
usb3613_hub_mode_ctrl(false);
}
static SIMPLE_DEV_PM_OPS(arche_platform_pm_ops,
arche_platform_suspend,
arche_platform_resume);
static const struct of_device_id arche_platform_of_match[] = {
/* Use PID/VID of SVC device */
{ .compatible = "google,arche-platform", },
{ },
};
static const struct of_device_id arche_combined_id[] = {
/* Use PID/VID of SVC device */
{ .compatible = "google,arche-platform", },
{ .compatible = "usbffff,2", },
{ },
};
MODULE_DEVICE_TABLE(of, arche_combined_id);
static struct platform_driver arche_platform_device_driver = {
.probe = arche_platform_probe,
.remove = arche_platform_remove,
.shutdown = arche_platform_shutdown,
.driver = {
.name = "arche-platform-ctrl",
.pm = &arche_platform_pm_ops,
.of_match_table = arche_platform_of_match,
}
};
static int __init arche_init(void)
{
int retval;
retval = platform_driver_register(&arche_platform_device_driver);
if (retval)
return retval;
retval = arche_apb_init();
if (retval)
platform_driver_unregister(&arche_platform_device_driver);
return retval;
}
module_init(arche_init);
static void __exit arche_exit(void)
{
arche_apb_exit();
platform_driver_unregister(&arche_platform_device_driver);
}
module_exit(arche_exit);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Vaibhav Hiremath <vaibhav.hiremath@linaro.org>");
MODULE_DESCRIPTION("Arche Platform Driver");