[PATCH 7/9] watchdog: of_xilinx_wdt: Add Versal Window watchdog support
Guenter Roeck
linux at roeck-us.net
Tue Mar 16 02:31:24 GMT 2021
On 3/15/21 3:46 AM, Srinivas Neeli wrote:
> Versal watchdog driver uses Window watchdog mode. Window watchdog
> timer(WWDT) contains closed(first) and open(second) window with
> 32 bit width. WWDT will generate an interrupt after the first window
> timeout and reset signal after the second window timeout. Timeout
> and Pre-timeout configuration, Stop and Refresh trigger only
> in open window.
>
> Signed-off-by: Srinivas Neeli <srinivas.neeli at xilinx.com>
I think this should be a separate watchdog driver. There is pretty much no overlap
with the existing driver.
Guenter
> ---
> drivers/watchdog/of_xilinx_wdt.c | 285 ++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 283 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/watchdog/of_xilinx_wdt.c b/drivers/watchdog/of_xilinx_wdt.c
> index 3b93b60f1a00..3656e716b4f7 100644
> --- a/drivers/watchdog/of_xilinx_wdt.c
> +++ b/drivers/watchdog/of_xilinx_wdt.c
> @@ -2,10 +2,11 @@
> /*
> * Watchdog Device Driver for Xilinx axi/xps_timebase_wdt
> *
> - * (C) Copyright 2013 - 2014 Xilinx, Inc.
> + * (C) Copyright 2013 - 2021 Xilinx, Inc.
> * (C) Copyright 2011 (Alejandro Cabrera <aldaya at gmail.com>)
> */
>
> +#include <linux/bits.h>
> #include <linux/clk.h>
> #include <linux/err.h>
> #include <linux/module.h>
> @@ -17,6 +18,11 @@
> #include <linux/of.h>
> #include <linux/of_device.h>
> #include <linux/of_address.h>
> +#include <linux/interrupt.h>
> +
> +#define XWT_WWDT_DEFAULT_TIMEOUT 10
> +#define XWT_WWDT_MIN_TIMEOUT 1
> +#define XWT_WWDT_MAX_TIMEOUT 42
>
> /* Register offsets for the Wdt device */
> #define XWT_TWCSR0_OFFSET 0x0 /* Control/Status Register0 */
> @@ -35,15 +41,44 @@
> #define XWT_MAX_SELFTEST_LOOP_COUNT 0x00010000
> #define XWT_TIMER_FAILED 0xFFFFFFFF
>
> +/* Register offsets for the WWdt device */
> +#define XWT_WWDT_MWR_OFFSET 0x00
> +#define XWT_WWDT_ESR_OFFSET 0x04
> +#define XWT_WWDT_FCR_OFFSET 0x08
> +#define XWT_WWDT_FWR_OFFSET 0x0c
> +#define XWT_WWDT_SWR_OFFSET 0x10
> +
> +/* Master Write Control Register Masks */
> +#define XWT_WWDT_MWR_MASK BIT(0)
> +
> +/* Enable and Status Register Masks */
> +#define XWT_WWDT_ESR_WINT_MASK BIT(16)
> +#define XWT_WWDT_ESR_WSW_MASK BIT(8)
> +#define XWT_WWDT_ESR_WEN_MASK BIT(0)
> +
> +/* Function control Register Masks */
> +#define XWT_WWDT_SBC_MASK 0xFF00
> +#define XWT_WWDT_SBC_SHIFT 16
> +#define XWT_WWDT_BSS_MASK 0xC0
> +
> #define WATCHDOG_NAME "Xilinx Watchdog"
>
> +static int wdt_timeout;
> +
> +module_param(wdt_timeout, int, 0644);
> +MODULE_PARM_DESC(wdt_timeout,
> + "Watchdog time in seconds. (default="
> + __MODULE_STRING(XWT_WWDT_DEFAULT_TIMEOUT) ")");
> +
> /**
> * enum xwdt_ip_type - WDT IP type.
> *
> * @XWDT_WDT: Soft wdt ip.
> + * @XWDT_WWDT: Window wdt ip.
> */
> enum xwdt_ip_type {
> XWDT_WDT = 0,
> + XWDT_WWDT = 1,
> };
>
> struct xwdt_devtype_data {
> @@ -58,6 +93,7 @@ struct xwdt_device {
> spinlock_t spinlock; /* spinlock for register handling */
> struct watchdog_device xilinx_wdt_wdd;
> struct clk *clk;
> + int irq;
> };
>
> static int xilinx_wdt_start(struct watchdog_device *wdd)
> @@ -145,6 +181,220 @@ static const struct watchdog_ops xilinx_wdt_ops = {
> .ping = xilinx_wdt_keepalive,
> };
>
> +static int is_wwdt_in_closed_window(struct watchdog_device *wdd)
> +{
> + u32 control_status_reg;
> + struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
> +
> + control_status_reg = ioread32(xdev->base + XWT_WWDT_ESR_OFFSET);
> + if (control_status_reg & XWT_WWDT_ESR_WEN_MASK)
> + if (!(control_status_reg & XWT_WWDT_ESR_WSW_MASK))
> + return 0;
> +
> + return 1;
> +}
> +
> +static int xilinx_wwdt_start(struct watchdog_device *wdd)
> +{
> + int ret;
> + u32 control_status_reg, fcr;
> + u64 time_out, pre_timeout, count;
> + struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
> + struct watchdog_device *xilinx_wdt_wdd = &xdev->xilinx_wdt_wdd;
> +
> + count = clk_get_rate(xdev->clk);
> + if (!count)
> + return -EINVAL;
> +
> + /* Calculate timeout count */
> + pre_timeout = count * wdd->pretimeout;
> + time_out = count * wdd->timeout;
> + if (!watchdog_active(xilinx_wdt_wdd)) {
> + ret = clk_enable(xdev->clk);
> + if (ret) {
> + dev_err(wdd->parent, "Failed to enable clock\n");
> + return ret;
> + }
> + }
> +
> + spin_lock(&xdev->spinlock);
> + iowrite32(XWT_WWDT_MWR_MASK, xdev->base + XWT_WWDT_MWR_OFFSET);
> + iowrite32(~(u32)XWT_WWDT_ESR_WEN_MASK,
> + xdev->base + XWT_WWDT_ESR_OFFSET);
> +
> + if (pre_timeout) {
> + iowrite32((u32)(time_out - pre_timeout),
> + xdev->base + XWT_WWDT_FWR_OFFSET);
> + iowrite32((u32)pre_timeout, xdev->base + XWT_WWDT_SWR_OFFSET);
> + fcr = ioread32(xdev->base + XWT_WWDT_SWR_OFFSET);
> + fcr = (fcr >> XWT_WWDT_SBC_SHIFT) & XWT_WWDT_SBC_MASK;
> + fcr = fcr | XWT_WWDT_BSS_MASK;
> + iowrite32(fcr, xdev->base + XWT_WWDT_FCR_OFFSET);
> + } else {
> + iowrite32((u32)pre_timeout,
> + xdev->base + XWT_WWDT_FWR_OFFSET);
> + iowrite32((u32)time_out, xdev->base + XWT_WWDT_SWR_OFFSET);
> + iowrite32(0x0, xdev->base + XWT_WWDT_FCR_OFFSET);
> + }
> +
> + /* Enable the window watchdog timer */
> + control_status_reg = ioread32(xdev->base + XWT_WWDT_ESR_OFFSET);
> + control_status_reg |= XWT_WWDT_ESR_WEN_MASK;
> + iowrite32(control_status_reg, xdev->base + XWT_WWDT_ESR_OFFSET);
> +
> + spin_unlock(&xdev->spinlock);
> +
> + dev_dbg(xilinx_wdt_wdd->parent, "Watchdog Started!\n");
> +
> + return 0;
> +}
> +
> +static int xilinx_wwdt_stop(struct watchdog_device *wdd)
> +{
> + struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
> + struct watchdog_device *xilinx_wdt_wdd = &xdev->xilinx_wdt_wdd;
> +
> + if (!is_wwdt_in_closed_window(wdd)) {
> + dev_warn(xilinx_wdt_wdd->parent, "timer in closed window");
> + return -EINVAL;
> + }
> +
> + spin_lock(&xdev->spinlock);
> +
> + iowrite32(XWT_WWDT_MWR_MASK, xdev->base + XWT_WWDT_MWR_OFFSET);
> + /* Disable the Window watchdog timer */
> + iowrite32(~(u32)XWT_WWDT_ESR_WEN_MASK,
> + xdev->base + XWT_WWDT_ESR_OFFSET);
> +
> + spin_unlock(&xdev->spinlock);
> +
> + if (watchdog_active(xilinx_wdt_wdd))
> + clk_disable(xdev->clk);
> +
> + dev_dbg(xilinx_wdt_wdd->parent, "Watchdog Stopped!\n");
> +
> + return 0;
> +}
> +
> +static int xilinx_wwdt_keepalive(struct watchdog_device *wdd)
> +{
> + u32 control_status_reg;
> + struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
> +
> + /* Refresh in open window is ignored */
> + if (!is_wwdt_in_closed_window(wdd))
> + return 0;
> +
> + spin_lock(&xdev->spinlock);
> +
> + iowrite32(XWT_WWDT_MWR_MASK, xdev->base + XWT_WWDT_MWR_OFFSET);
> + control_status_reg = ioread32(xdev->base + XWT_WWDT_ESR_OFFSET);
> + control_status_reg |= XWT_WWDT_ESR_WINT_MASK;
> + control_status_reg &= ~XWT_WWDT_ESR_WSW_MASK;
> + iowrite32(control_status_reg, xdev->base + XWT_WWDT_ESR_OFFSET);
> + control_status_reg = ioread32(xdev->base + XWT_WWDT_ESR_OFFSET);
> + control_status_reg |= XWT_WWDT_ESR_WSW_MASK;
> + iowrite32(control_status_reg, xdev->base + XWT_WWDT_ESR_OFFSET);
> +
> + spin_unlock(&xdev->spinlock);
> +
> + return 0;
> +}
> +
> +static int xilinx_wwdt_set_timeout(struct watchdog_device *wdd,
> + unsigned int new_time)
> +{
> + u32 ret = 0;
> + struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
> + struct watchdog_device *xilinx_wdt_wdd = &xdev->xilinx_wdt_wdd;
> +
> + if (!is_wwdt_in_closed_window(wdd)) {
> + dev_warn(xilinx_wdt_wdd->parent, "timer in closed window");
> + return -EINVAL;
> + }
> +
> + if (new_time < XWT_WWDT_MIN_TIMEOUT ||
> + new_time > XWT_WWDT_MAX_TIMEOUT) {
> + dev_warn(xilinx_wdt_wdd->parent,
> + "timeout value must be %d<=x<=%d, using %d\n",
> + XWT_WWDT_MIN_TIMEOUT,
> + XWT_WWDT_MAX_TIMEOUT, new_time);
> + return -EINVAL;
> + }
> +
> + wdd->timeout = new_time;
> + wdd->pretimeout = 0;
> +
> + if (watchdog_active(xilinx_wdt_wdd)) {
> + ret = xilinx_wwdt_start(wdd);
> + if (ret)
> + dev_dbg(xilinx_wdt_wdd->parent, "timer start failed");
> + }
> +
> + return 0;
> +}
> +
> +static int xilinx_wwdt_set_pretimeout(struct watchdog_device *wdd,
> + u32 new_pretimeout)
> +{
> + u32 ret = 0;
> + struct xwdt_device *xdev = watchdog_get_drvdata(wdd);
> + struct watchdog_device *xilinx_wdt_wdd = &xdev->xilinx_wdt_wdd;
> +
> + if (!is_wwdt_in_closed_window(wdd)) {
> + dev_warn(xilinx_wdt_wdd->parent, "timer in closed window");
> + return -EINVAL;
> + }
> +
> + if (new_pretimeout < wdd->min_timeout ||
> + new_pretimeout >= wdd->timeout)
> + return -EINVAL;
> +
> + wdd->pretimeout = new_pretimeout;
> +
> + if (watchdog_active(xilinx_wdt_wdd)) {
> + ret = xilinx_wwdt_start(wdd);
> + if (ret)
> + dev_dbg(xilinx_wdt_wdd->parent, "timer start failed");
> + }
> +
> + return 0;
> +}
> +
> +static irqreturn_t xilinx_wwdt_isr(int irq, void *wdog_arg)
> +{
> + struct xwdt_device *xdev = wdog_arg;
> +
> + watchdog_notify_pretimeout(&xdev->xilinx_wdt_wdd);
> + return IRQ_HANDLED;
> +}
> +
> +static const struct watchdog_info xilinx_wwdt_ident = {
> + .options = WDIOF_MAGICCLOSE |
> + WDIOF_KEEPALIVEPING |
> + WDIOF_SETTIMEOUT,
> + .firmware_version = 1,
> + .identity = "xlnx_wwdt watchdog",
> +};
> +
> +static const struct watchdog_info xilinx_wwdt_pretimeout_ident = {
> + .options = WDIOF_MAGICCLOSE |
> + WDIOF_KEEPALIVEPING |
> + WDIOF_PRETIMEOUT |
> + WDIOF_SETTIMEOUT,
> + .firmware_version = 1,
> + .identity = "xlnx_wwdt watchdog",
> +};
> +
> +static const struct watchdog_ops xilinx_wwdt_ops = {
> + .owner = THIS_MODULE,
> + .start = xilinx_wwdt_start,
> + .stop = xilinx_wwdt_stop,
> + .ping = xilinx_wwdt_keepalive,
> + .set_timeout = xilinx_wwdt_set_timeout,
> + .set_pretimeout = xilinx_wwdt_set_pretimeout,
> +};
> +
> static u32 xwdt_selftest(struct xwdt_device *xdev)
> {
> int i;
> @@ -181,11 +431,19 @@ static const struct xwdt_devtype_data xwdt_wdt_data = {
> .xwdt_ops = &xilinx_wdt_ops,
> };
>
> +static const struct xwdt_devtype_data xwdt_wwdt_data = {
> + .wdttype = XWDT_WWDT,
> + .xwdt_info = &xilinx_wwdt_ident,
> + .xwdt_ops = &xilinx_wwdt_ops,
> +};
> +
> static const struct of_device_id xwdt_of_match[] = {
> { .compatible = "xlnx,xps-timebase-wdt-1.00.a",
> .data = &xwdt_wdt_data },
> { .compatible = "xlnx,xps-timebase-wdt-1.01.a",
> .data = &xwdt_wdt_data },
> + { .compatible = "xlnx,versal-wwdt-1.0",
> + .data = &xwdt_wwdt_data },
> {},
> };
> MODULE_DEVICE_TABLE(of, xwdt_of_match);
> @@ -194,7 +452,7 @@ static int xwdt_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> int rc;
> - u32 pfreq = 0, enable_once = 0;
> + u32 pfreq = 0, enable_once = 0, pre_timeout = 0;
> struct xwdt_device *xdev;
> struct watchdog_device *xilinx_wdt_wdd;
> const struct of_device_id *of_id;
> @@ -236,6 +494,12 @@ static int xwdt_probe(struct platform_device *pdev)
> "Parameter \"xlnx,wdt-enable-once\" not found\n");
>
> watchdog_set_nowayout(xilinx_wdt_wdd, enable_once);
> + } else {
> + rc = of_property_read_u32(dev->of_node, "pretimeout-sec",
> + &pre_timeout);
> + if (rc)
> + dev_dbg(dev,
> + "Parameter \"pretimeout-sec\" not found\n");
> }
>
> xdev->clk = devm_clk_get(dev, NULL);
> @@ -268,6 +532,23 @@ static int xwdt_probe(struct platform_device *pdev)
> xilinx_wdt_wdd->timeout =
> 2 * ((1 << xdev->wdt_interval) /
> pfreq);
> + } else {
> + xilinx_wdt_wdd->pretimeout = pre_timeout;
> + xilinx_wdt_wdd->timeout = XWT_WWDT_DEFAULT_TIMEOUT;
> + xilinx_wdt_wdd->min_timeout = XWT_WWDT_MIN_TIMEOUT;
> + xilinx_wdt_wdd->max_timeout = XWT_WWDT_MAX_TIMEOUT;
> + xdev->irq = platform_get_irq_byname(pdev, "wdt");
> + if (xdev->irq > 0) {
> + if (!devm_request_irq(dev, xdev->irq, xilinx_wwdt_isr,
> + 0, dev_name(dev), xdev)) {
> + xilinx_wdt_wdd->info =
> + &xilinx_wwdt_pretimeout_ident;
> + }
> + }
> + rc = watchdog_init_timeout(xilinx_wdt_wdd,
> + wdt_timeout, &pdev->dev);
> + if (rc)
> + dev_warn(&pdev->dev, "unable to set timeout value\n");
> }
>
> spin_lock_init(&xdev->spinlock);
>
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