forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
345 lines
8.2 KiB
345 lines
8.2 KiB
// SPDX-License-Identifier: GPL-2.0 |
|
/* |
|
* Watchdog driver for the K3 RTI module |
|
* |
|
* (c) Copyright 2019-2020 Texas Instruments Inc. |
|
* All rights reserved. |
|
*/ |
|
|
|
#include <linux/clk.h> |
|
#include <linux/device.h> |
|
#include <linux/err.h> |
|
#include <linux/io.h> |
|
#include <linux/kernel.h> |
|
#include <linux/mod_devicetable.h> |
|
#include <linux/module.h> |
|
#include <linux/moduleparam.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/pm_runtime.h> |
|
#include <linux/types.h> |
|
#include <linux/watchdog.h> |
|
|
|
#define DEFAULT_HEARTBEAT 60 |
|
|
|
/* Max heartbeat is calculated at 32kHz source clock */ |
|
#define MAX_HEARTBEAT 1000 |
|
|
|
/* Timer register set definition */ |
|
#define RTIDWDCTRL 0x90 |
|
#define RTIDWDPRLD 0x94 |
|
#define RTIWDSTATUS 0x98 |
|
#define RTIWDKEY 0x9c |
|
#define RTIDWDCNTR 0xa0 |
|
#define RTIWWDRXCTRL 0xa4 |
|
#define RTIWWDSIZECTRL 0xa8 |
|
|
|
#define RTIWWDRX_NMI 0xa |
|
|
|
#define RTIWWDSIZE_50P 0x50 |
|
#define RTIWWDSIZE_25P 0x500 |
|
#define RTIWWDSIZE_12P5 0x5000 |
|
#define RTIWWDSIZE_6P25 0x50000 |
|
#define RTIWWDSIZE_3P125 0x500000 |
|
|
|
#define WDENABLE_KEY 0xa98559da |
|
|
|
#define WDKEY_SEQ0 0xe51a |
|
#define WDKEY_SEQ1 0xa35c |
|
|
|
#define WDT_PRELOAD_SHIFT 13 |
|
|
|
#define WDT_PRELOAD_MAX 0xfff |
|
|
|
#define DWDST BIT(1) |
|
|
|
static int heartbeat = DEFAULT_HEARTBEAT; |
|
|
|
/* |
|
* struct to hold data for each WDT device |
|
* @base - base io address of WD device |
|
* @freq - source clock frequency of WDT |
|
* @wdd - hold watchdog device as is in WDT core |
|
*/ |
|
struct rti_wdt_device { |
|
void __iomem *base; |
|
unsigned long freq; |
|
struct watchdog_device wdd; |
|
}; |
|
|
|
static int rti_wdt_start(struct watchdog_device *wdd) |
|
{ |
|
u32 timer_margin; |
|
struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd); |
|
|
|
/* set timeout period */ |
|
timer_margin = (u64)wdd->timeout * wdt->freq; |
|
timer_margin >>= WDT_PRELOAD_SHIFT; |
|
if (timer_margin > WDT_PRELOAD_MAX) |
|
timer_margin = WDT_PRELOAD_MAX; |
|
writel_relaxed(timer_margin, wdt->base + RTIDWDPRLD); |
|
|
|
/* |
|
* RTI only supports a windowed mode, where the watchdog can only |
|
* be petted during the open window; not too early or not too late. |
|
* The HW configuration options only allow for the open window size |
|
* to be 50% or less than that; we obviouly want to configure the open |
|
* window as large as possible so we select the 50% option. |
|
*/ |
|
wdd->min_hw_heartbeat_ms = 500 * wdd->timeout; |
|
|
|
/* Generate NMI when wdt expires */ |
|
writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL); |
|
|
|
/* Open window size 50%; this is the largest window size available */ |
|
writel_relaxed(RTIWWDSIZE_50P, wdt->base + RTIWWDSIZECTRL); |
|
|
|
readl_relaxed(wdt->base + RTIWWDSIZECTRL); |
|
|
|
/* enable watchdog */ |
|
writel_relaxed(WDENABLE_KEY, wdt->base + RTIDWDCTRL); |
|
return 0; |
|
} |
|
|
|
static int rti_wdt_ping(struct watchdog_device *wdd) |
|
{ |
|
struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd); |
|
|
|
/* put watchdog in service state */ |
|
writel_relaxed(WDKEY_SEQ0, wdt->base + RTIWDKEY); |
|
/* put watchdog in active state */ |
|
writel_relaxed(WDKEY_SEQ1, wdt->base + RTIWDKEY); |
|
|
|
return 0; |
|
} |
|
|
|
static int rti_wdt_setup_hw_hb(struct watchdog_device *wdd, u32 wsize) |
|
{ |
|
/* |
|
* RTI only supports a windowed mode, where the watchdog can only |
|
* be petted during the open window; not too early or not too late. |
|
* The HW configuration options only allow for the open window size |
|
* to be 50% or less than that. |
|
*/ |
|
switch (wsize) { |
|
case RTIWWDSIZE_50P: |
|
/* 50% open window => 50% min heartbeat */ |
|
wdd->min_hw_heartbeat_ms = 500 * heartbeat; |
|
break; |
|
|
|
case RTIWWDSIZE_25P: |
|
/* 25% open window => 75% min heartbeat */ |
|
wdd->min_hw_heartbeat_ms = 750 * heartbeat; |
|
break; |
|
|
|
case RTIWWDSIZE_12P5: |
|
/* 12.5% open window => 87.5% min heartbeat */ |
|
wdd->min_hw_heartbeat_ms = 875 * heartbeat; |
|
break; |
|
|
|
case RTIWWDSIZE_6P25: |
|
/* 6.5% open window => 93.5% min heartbeat */ |
|
wdd->min_hw_heartbeat_ms = 935 * heartbeat; |
|
break; |
|
|
|
case RTIWWDSIZE_3P125: |
|
/* 3.125% open window => 96.9% min heartbeat */ |
|
wdd->min_hw_heartbeat_ms = 969 * heartbeat; |
|
break; |
|
|
|
default: |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static unsigned int rti_wdt_get_timeleft_ms(struct watchdog_device *wdd) |
|
{ |
|
u64 timer_counter; |
|
u32 val; |
|
struct rti_wdt_device *wdt = watchdog_get_drvdata(wdd); |
|
|
|
/* if timeout has occurred then return 0 */ |
|
val = readl_relaxed(wdt->base + RTIWDSTATUS); |
|
if (val & DWDST) |
|
return 0; |
|
|
|
timer_counter = readl_relaxed(wdt->base + RTIDWDCNTR); |
|
|
|
timer_counter *= 1000; |
|
|
|
do_div(timer_counter, wdt->freq); |
|
|
|
return timer_counter; |
|
} |
|
|
|
static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) |
|
{ |
|
return rti_wdt_get_timeleft_ms(wdd) / 1000; |
|
} |
|
|
|
static const struct watchdog_info rti_wdt_info = { |
|
.options = WDIOF_KEEPALIVEPING, |
|
.identity = "K3 RTI Watchdog", |
|
}; |
|
|
|
static const struct watchdog_ops rti_wdt_ops = { |
|
.owner = THIS_MODULE, |
|
.start = rti_wdt_start, |
|
.ping = rti_wdt_ping, |
|
.get_timeleft = rti_wdt_get_timeleft, |
|
}; |
|
|
|
static int rti_wdt_probe(struct platform_device *pdev) |
|
{ |
|
int ret = 0; |
|
struct device *dev = &pdev->dev; |
|
struct resource *wdt_mem; |
|
struct watchdog_device *wdd; |
|
struct rti_wdt_device *wdt; |
|
struct clk *clk; |
|
u32 last_ping = 0; |
|
|
|
wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); |
|
if (!wdt) |
|
return -ENOMEM; |
|
|
|
clk = clk_get(dev, NULL); |
|
if (IS_ERR(clk)) |
|
return dev_err_probe(dev, PTR_ERR(clk), "failed to get clock\n"); |
|
|
|
wdt->freq = clk_get_rate(clk); |
|
|
|
clk_put(clk); |
|
|
|
if (!wdt->freq) { |
|
dev_err(dev, "Failed to get fck rate.\n"); |
|
return -EINVAL; |
|
} |
|
|
|
/* |
|
* If watchdog is running at 32k clock, it is not accurate. |
|
* Adjust frequency down in this case so that we don't pet |
|
* the watchdog too often. |
|
*/ |
|
if (wdt->freq < 32768) |
|
wdt->freq = wdt->freq * 9 / 10; |
|
|
|
pm_runtime_enable(dev); |
|
ret = pm_runtime_get_sync(dev); |
|
if (ret) { |
|
pm_runtime_put_noidle(dev); |
|
return dev_err_probe(dev, ret, "runtime pm failed\n"); |
|
} |
|
|
|
platform_set_drvdata(pdev, wdt); |
|
|
|
wdd = &wdt->wdd; |
|
wdd->info = &rti_wdt_info; |
|
wdd->ops = &rti_wdt_ops; |
|
wdd->min_timeout = 1; |
|
wdd->max_hw_heartbeat_ms = (WDT_PRELOAD_MAX << WDT_PRELOAD_SHIFT) / |
|
wdt->freq * 1000; |
|
wdd->parent = dev; |
|
|
|
watchdog_set_drvdata(wdd, wdt); |
|
watchdog_set_nowayout(wdd, 1); |
|
watchdog_set_restart_priority(wdd, 128); |
|
|
|
wdt_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
|
wdt->base = devm_ioremap_resource(dev, wdt_mem); |
|
if (IS_ERR(wdt->base)) { |
|
ret = PTR_ERR(wdt->base); |
|
goto err_iomap; |
|
} |
|
|
|
if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) { |
|
u32 time_left_ms; |
|
u64 heartbeat_ms; |
|
u32 wsize; |
|
|
|
set_bit(WDOG_HW_RUNNING, &wdd->status); |
|
time_left_ms = rti_wdt_get_timeleft_ms(wdd); |
|
heartbeat_ms = readl(wdt->base + RTIDWDPRLD); |
|
heartbeat_ms <<= WDT_PRELOAD_SHIFT; |
|
heartbeat_ms *= 1000; |
|
do_div(heartbeat_ms, wdt->freq); |
|
if (heartbeat_ms != heartbeat * 1000) |
|
dev_warn(dev, "watchdog already running, ignoring heartbeat config!\n"); |
|
|
|
heartbeat = heartbeat_ms; |
|
heartbeat /= 1000; |
|
|
|
wsize = readl(wdt->base + RTIWWDSIZECTRL); |
|
ret = rti_wdt_setup_hw_hb(wdd, wsize); |
|
if (ret) { |
|
dev_err(dev, "bad window size.\n"); |
|
goto err_iomap; |
|
} |
|
|
|
last_ping = heartbeat_ms - time_left_ms; |
|
if (time_left_ms > heartbeat_ms) { |
|
dev_warn(dev, "time_left > heartbeat? Assuming last ping just before now.\n"); |
|
last_ping = 0; |
|
} |
|
} |
|
|
|
watchdog_init_timeout(wdd, heartbeat, dev); |
|
|
|
ret = watchdog_register_device(wdd); |
|
if (ret) { |
|
dev_err(dev, "cannot register watchdog device\n"); |
|
goto err_iomap; |
|
} |
|
|
|
if (last_ping) |
|
watchdog_set_last_hw_keepalive(wdd, last_ping); |
|
|
|
return 0; |
|
|
|
err_iomap: |
|
pm_runtime_put_sync(&pdev->dev); |
|
pm_runtime_disable(&pdev->dev); |
|
|
|
return ret; |
|
} |
|
|
|
static int rti_wdt_remove(struct platform_device *pdev) |
|
{ |
|
struct rti_wdt_device *wdt = platform_get_drvdata(pdev); |
|
|
|
watchdog_unregister_device(&wdt->wdd); |
|
pm_runtime_put(&pdev->dev); |
|
pm_runtime_disable(&pdev->dev); |
|
|
|
return 0; |
|
} |
|
|
|
static const struct of_device_id rti_wdt_of_match[] = { |
|
{ .compatible = "ti,j7-rti-wdt", }, |
|
{}, |
|
}; |
|
MODULE_DEVICE_TABLE(of, rti_wdt_of_match); |
|
|
|
static struct platform_driver rti_wdt_driver = { |
|
.driver = { |
|
.name = "rti-wdt", |
|
.of_match_table = rti_wdt_of_match, |
|
}, |
|
.probe = rti_wdt_probe, |
|
.remove = rti_wdt_remove, |
|
}; |
|
|
|
module_platform_driver(rti_wdt_driver); |
|
|
|
MODULE_AUTHOR("Tero Kristo <[email protected]>"); |
|
MODULE_DESCRIPTION("K3 RTI Watchdog Driver"); |
|
|
|
module_param(heartbeat, int, 0); |
|
MODULE_PARM_DESC(heartbeat, |
|
"Watchdog heartbeat period in seconds from 1 to " |
|
__MODULE_STRING(MAX_HEARTBEAT) ", default " |
|
__MODULE_STRING(DEFAULT_HEARTBEAT)); |
|
|
|
MODULE_LICENSE("GPL"); |
|
MODULE_ALIAS("platform:rti-wdt");
|
|
|