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|
/*
* drivers/watchdog/orion_wdt.c
*
* Watchdog driver for Orion/Kirkwood processors
*
* Author: Sylver Bruneau <sylver.bruneau@googlemail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/of_device.h>
/* RSTOUT mask register physical address for Orion5x, Kirkwood and Dove */
#define ORION_RSTOUT_MASK_OFFSET 0x20108
/* Internal registers can be configured at any 1 MiB aligned address */
#define INTERNAL_REGS_MASK ~(SZ_1M - 1)
/*
* Watchdog timer block registers.
*/
#define TIMER_CTRL 0x0000
#define TIMER_A370_STATUS 0x04
#define WDT_MAX_CYCLE_COUNT 0xffffffff
#define WDT_A370_RATIO_MASK(v) ((v) << 16)
#define WDT_A370_RATIO_SHIFT 5
#define WDT_A370_RATIO (1 << WDT_A370_RATIO_SHIFT)
#define WDT_AXP_FIXED_ENABLE_BIT BIT(10)
#define WDT_A370_EXPIRED BIT(31)
static bool nowayout = WATCHDOG_NOWAYOUT;
static int heartbeat = -1; /* module parameter (seconds) */
struct orion_watchdog;
struct orion_watchdog_data {
int wdt_counter_offset;
int wdt_enable_bit;
int rstout_enable_bit;
int (*clock_init)(struct platform_device *,
struct orion_watchdog *);
int (*start)(struct watchdog_device *);
int (*stop)(struct watchdog_device *);
};
struct orion_watchdog {
struct watchdog_device wdt;
void __iomem *reg;
void __iomem *rstout;
unsigned long clk_rate;
struct clk *clk;
const struct orion_watchdog_data *data;
};
static int orion_wdt_clock_init(struct platform_device *pdev,
struct orion_watchdog *dev)
{
int ret;
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk))
return PTR_ERR(dev->clk);
ret = clk_prepare_enable(dev->clk);
if (ret) {
clk_put(dev->clk);
return ret;
}
dev->clk_rate = clk_get_rate(dev->clk);
return 0;
}
static int armada370_wdt_clock_init(struct platform_device *pdev,
struct orion_watchdog *dev)
{
int ret;
dev->clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(dev->clk))
return PTR_ERR(dev->clk);
ret = clk_prepare_enable(dev->clk);
if (ret) {
clk_put(dev->clk);
return ret;
}
/* Setup watchdog input clock */
atomic_io_modify(dev->reg + TIMER_CTRL,
WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT),
WDT_A370_RATIO_MASK(WDT_A370_RATIO_SHIFT));
dev->clk_rate = clk_get_rate(dev->clk) / WDT_A370_RATIO;
return 0;
}
static int armadaxp_wdt_clock_init(struct platform_device *pdev,
struct orion_watchdog *dev)
{
int ret;
dev->clk = of_clk_get_by_name(pdev->dev.of_node, "fixed");
if (IS_ERR(dev->clk))
return PTR_ERR(dev->clk);
ret = clk_prepare_enable(dev->clk);
if (ret) {
clk_put(dev->clk);
return ret;
}
/* Enable the fixed watchdog clock input */
atomic_io_modify(dev->reg + TIMER_CTRL,
WDT_AXP_FIXED_ENABLE_BIT,
WDT_AXP_FIXED_ENABLE_BIT);
dev->clk_rate = clk_get_rate(dev->clk);
return 0;
}
static int orion_wdt_ping(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
/* Reload watchdog duration */
writel(dev->clk_rate * wdt_dev->timeout,
dev->reg + dev->data->wdt_counter_offset);
return 0;
}
static int armada370_start(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
u32 reg;
/* Set watchdog duration */
writel(dev->clk_rate * wdt_dev->timeout,
dev->reg + dev->data->wdt_counter_offset);
/* Clear the watchdog expiration bit */
atomic_io_modify(dev->reg + TIMER_A370_STATUS, WDT_A370_EXPIRED, 0);
/* Enable watchdog timer */
atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
dev->data->wdt_enable_bit);
/* Enable reset on watchdog */
reg = readl(dev->rstout);
reg |= dev->data->rstout_enable_bit;
writel(reg, dev->rstout);
return 0;
}
static int orion_start(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
/* Set watchdog duration */
writel(dev->clk_rate * wdt_dev->timeout,
dev->reg + dev->data->wdt_counter_offset);
/* Enable watchdog timer */
atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit,
dev->data->wdt_enable_bit);
/* Enable reset on watchdog */
atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit,
dev->data->rstout_enable_bit);
return 0;
}
static int orion_wdt_start(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
/* There are some per-SoC quirks to handle */
return dev->data->start(wdt_dev);
}
static int orion_stop(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
/* Disable reset on watchdog */
atomic_io_modify(dev->rstout, dev->data->rstout_enable_bit, 0);
/* Disable watchdog timer */
atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
return 0;
}
static int armada370_stop(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
u32 reg;
/* Disable reset on watchdog */
reg = readl(dev->rstout);
reg &= ~dev->data->rstout_enable_bit;
writel(reg, dev->rstout);
/* Disable watchdog timer */
atomic_io_modify(dev->reg + TIMER_CTRL, dev->data->wdt_enable_bit, 0);
return 0;
}
static int orion_wdt_stop(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
return dev->data->stop(wdt_dev);
}
static int orion_wdt_enabled(struct orion_watchdog *dev)
{
bool enabled, running;
enabled = readl(dev->rstout) & dev->data->rstout_enable_bit;
running = readl(dev->reg + TIMER_CTRL) & dev->data->wdt_enable_bit;
return enabled && running;
}
static unsigned int orion_wdt_get_timeleft(struct watchdog_device *wdt_dev)
{
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
return readl(dev->reg + dev->data->wdt_counter_offset) / dev->clk_rate;
}
static int orion_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
wdt_dev->timeout = timeout;
return 0;
}
static const struct watchdog_info orion_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "Orion Watchdog",
};
static const struct watchdog_ops orion_wdt_ops = {
.owner = THIS_MODULE,
.start = orion_wdt_start,
.stop = orion_wdt_stop,
.ping = orion_wdt_ping,
.set_timeout = orion_wdt_set_timeout,
.get_timeleft = orion_wdt_get_timeleft,
};
static irqreturn_t orion_wdt_irq(int irq, void *devid)
{
panic("Watchdog Timeout");
return IRQ_HANDLED;
}
/*
* The original devicetree binding for this driver specified only
* one memory resource, so in order to keep DT backwards compatibility
* we try to fallback to a hardcoded register address, if the resource
* is missing from the devicetree.
*/
static void __iomem *orion_wdt_ioremap_rstout(struct platform_device *pdev,
phys_addr_t internal_regs)
{
struct resource *res;
phys_addr_t rstout;
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (res)
return devm_ioremap(&pdev->dev, res->start,
resource_size(res));
rstout = internal_regs + ORION_RSTOUT_MASK_OFFSET;
WARN(1, FW_BUG "falling back to harcoded RSTOUT reg %pa\n", &rstout);
return devm_ioremap(&pdev->dev, rstout, 0x4);
}
static const struct orion_watchdog_data orion_data = {
.rstout_enable_bit = BIT(1),
.wdt_enable_bit = BIT(4),
.wdt_counter_offset = 0x24,
.clock_init = orion_wdt_clock_init,
.start = orion_start,
.stop = orion_stop,
};
static const struct orion_watchdog_data armada370_data = {
.rstout_enable_bit = BIT(8),
.wdt_enable_bit = BIT(8),
.wdt_counter_offset = 0x34,
.clock_init = armada370_wdt_clock_init,
.start = armada370_start,
.stop = armada370_stop,
};
static const struct orion_watchdog_data armadaxp_data = {
.rstout_enable_bit = BIT(8),
.wdt_enable_bit = BIT(8),
.wdt_counter_offset = 0x34,
.clock_init = armadaxp_wdt_clock_init,
.start = armada370_start,
.stop = armada370_stop,
};
static const struct of_device_id orion_wdt_of_match_table[] = {
{
.compatible = "marvell,orion-wdt",
.data = &orion_data,
},
{
.compatible = "marvell,armada-370-wdt",
.data = &armada370_data,
},
{
.compatible = "marvell,armada-xp-wdt",
.data = &armadaxp_data,
},
{},
};
MODULE_DEVICE_TABLE(of, orion_wdt_of_match_table);
static int orion_wdt_get_regs(struct platform_device *pdev,
struct orion_watchdog *dev)
{
struct device_node *node = pdev->dev.of_node;
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
dev->reg = devm_ioremap(&pdev->dev, res->start,
resource_size(res));
if (!dev->reg)
return -ENOMEM;
/* Each supported compatible has some RSTOUT register quirk */
if (of_device_is_compatible(node, "marvell,orion-wdt")) {
dev->rstout = orion_wdt_ioremap_rstout(pdev, res->start &
INTERNAL_REGS_MASK);
if (!dev->rstout)
return -ENODEV;
} else if (of_device_is_compatible(node, "marvell,armada-370-wdt") ||
of_device_is_compatible(node, "marvell,armada-xp-wdt")) {
/* Dedicated RSTOUT register, can be requested. */
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
dev->rstout = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(dev->rstout))
return PTR_ERR(dev->rstout);
} else {
return -ENODEV;
}
return 0;
}
static int orion_wdt_probe(struct platform_device *pdev)
{
struct orion_watchdog *dev;
const struct of_device_id *match;
unsigned int wdt_max_duration; /* (seconds) */
int ret, irq;
dev = devm_kzalloc(&pdev->dev, sizeof(struct orion_watchdog),
GFP_KERNEL);
if (!dev)
return -ENOMEM;
match = of_match_device(orion_wdt_of_match_table, &pdev->dev);
if (!match)
/* Default legacy match */
match = &orion_wdt_of_match_table[0];
dev->wdt.info = &orion_wdt_info;
dev->wdt.ops = &orion_wdt_ops;
dev->wdt.min_timeout = 1;
dev->data = match->data;
ret = orion_wdt_get_regs(pdev, dev);
if (ret)
return ret;
ret = dev->data->clock_init(pdev, dev);
if (ret) {
dev_err(&pdev->dev, "cannot initialize clock\n");
return ret;
}
wdt_max_duration = WDT_MAX_CYCLE_COUNT / dev->clk_rate;
dev->wdt.timeout = wdt_max_duration;
dev->wdt.max_timeout = wdt_max_duration;
watchdog_init_timeout(&dev->wdt, heartbeat, &pdev->dev);
platform_set_drvdata(pdev, &dev->wdt);
watchdog_set_drvdata(&dev->wdt, dev);
/*
* Let's make sure the watchdog is fully stopped, unless it's
* explicitly enabled. This may be the case if the module was
* removed and re-insterted, or if the bootloader explicitly
* set a running watchdog before booting the kernel.
*/
if (!orion_wdt_enabled(dev))
orion_wdt_stop(&dev->wdt);
/* Request the IRQ only after the watchdog is disabled */
irq = platform_get_irq(pdev, 0);
if (irq > 0) {
/*
* Not all supported platforms specify an interrupt for the
* watchdog, so let's make it optional.
*/
ret = devm_request_irq(&pdev->dev, irq, orion_wdt_irq, 0,
pdev->name, dev);
if (ret < 0) {
dev_err(&pdev->dev, "failed to request IRQ\n");
goto disable_clk;
}
}
watchdog_set_nowayout(&dev->wdt, nowayout);
ret = watchdog_register_device(&dev->wdt);
if (ret)
goto disable_clk;
pr_info("Initial timeout %d sec%s\n",
dev->wdt.timeout, nowayout ? ", nowayout" : "");
return 0;
disable_clk:
clk_disable_unprepare(dev->clk);
clk_put(dev->clk);
return ret;
}
static int orion_wdt_remove(struct platform_device *pdev)
{
struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
struct orion_watchdog *dev = watchdog_get_drvdata(wdt_dev);
watchdog_unregister_device(wdt_dev);
clk_disable_unprepare(dev->clk);
clk_put(dev->clk);
return 0;
}
static void orion_wdt_shutdown(struct platform_device *pdev)
{
struct watchdog_device *wdt_dev = platform_get_drvdata(pdev);
orion_wdt_stop(wdt_dev);
}
static struct platform_driver orion_wdt_driver = {
.probe = orion_wdt_probe,
.remove = orion_wdt_remove,
.shutdown = orion_wdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = "orion_wdt",
.of_match_table = orion_wdt_of_match_table,
},
};
module_platform_driver(orion_wdt_driver);
MODULE_AUTHOR("Sylver Bruneau <sylver.bruneau@googlemail.com>");
MODULE_DESCRIPTION("Orion Processor Watchdog");
module_param(heartbeat, int, 0);
MODULE_PARM_DESC(heartbeat, "Initial watchdog heartbeat in seconds");
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:orion_wdt");
|