On Fri, Oct 21, 2022 at 10:15:58AM -0500, Eddie James wrote:
> Enable the pre-timeout interrupt if requested by device property.
>
I am not inclined to accept this patch without detailed explanation.
Why would it make sense and/or be desirable to completely bypass the
watchdog core with this pretimeout support ?
Thanks,
Guenter
> Signed-off-by: Eddie James <eajames@xxxxxxxxxxxxx>
> ---
> drivers/watchdog/aspeed_wdt.c | 53 +++++++++++++++++++++++++++++++++--
> 1 file changed, 51 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c
> index 0cff2adfbfc9..8e12181a827e 100644
> --- a/drivers/watchdog/aspeed_wdt.c
> +++ b/drivers/watchdog/aspeed_wdt.c
> @@ -5,11 +5,14 @@
> * Joel Stanley <joel@xxxxxxxxx>
> */
>
> +#include <linux/bits.h>
> #include <linux/delay.h>
> +#include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/of.h>
> +#include <linux/of_irq.h>
> #include <linux/platform_device.h>
> #include <linux/watchdog.h>
>
> @@ -26,20 +29,32 @@ struct aspeed_wdt {
>
> struct aspeed_wdt_config {
> u32 ext_pulse_width_mask;
> + u32 irq_shift;
> + u32 irq_mask;
> };
>
> static const struct aspeed_wdt_config ast2400_config = {
> .ext_pulse_width_mask = 0xff,
> + .irq_shift = 0,
> + .irq_mask = 0,
> };
>
> static const struct aspeed_wdt_config ast2500_config = {
> .ext_pulse_width_mask = 0xfffff,
> + .irq_shift = 12,
> + .irq_mask = GENMASK(31, 12),
> +};
> +
> +static const struct aspeed_wdt_config ast2600_config = {
> + .ext_pulse_width_mask = 0xfffff,
> + .irq_shift = 0,
> + .irq_mask = GENMASK(31, 10),
> };
>
> static const struct of_device_id aspeed_wdt_of_table[] = {
> { .compatible = "aspeed,ast2400-wdt", .data = &ast2400_config },
> { .compatible = "aspeed,ast2500-wdt", .data = &ast2500_config },
> - { .compatible = "aspeed,ast2600-wdt", .data = &ast2500_config },
> + { .compatible = "aspeed,ast2600-wdt", .data = &ast2600_config },
> { },
> };
> MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
> @@ -58,6 +73,7 @@ MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table);
> #define WDT_CTRL_RESET_SYSTEM BIT(1)
> #define WDT_CTRL_ENABLE BIT(0)
> #define WDT_TIMEOUT_STATUS 0x10
> +#define WDT_TIMEOUT_STATUS_IRQ BIT(2)
> #define WDT_TIMEOUT_STATUS_BOOT_SECONDARY BIT(1)
> #define WDT_CLEAR_TIMEOUT_STATUS 0x14
> #define WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION BIT(0)
> @@ -243,6 +259,17 @@ static const struct watchdog_info aspeed_wdt_info = {
> .identity = KBUILD_MODNAME,
> };
>
> +static irqreturn_t aspeed_wdt_irq(int irq, void *arg)
> +{
> + struct aspeed_wdt *wdt = arg;
> + u32 status = readl(wdt->base + WDT_TIMEOUT_STATUS);
> +
> + if (status & WDT_TIMEOUT_STATUS_IRQ)
> + panic("Watchdog pre-timeout IRQ");
> +
> + return IRQ_NONE;
> +}
> +
> static int aspeed_wdt_probe(struct platform_device *pdev)
> {
> struct device *dev = &pdev->dev;
> @@ -253,6 +280,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
> const char *reset_type;
> u32 duration;
> u32 status;
> + u32 timeout = 0;
> int ret;
>
> wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
> @@ -291,6 +319,27 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
> if (of_device_is_compatible(np, "aspeed,ast2400-wdt"))
> wdt->ctrl = WDT_CTRL_1MHZ_CLK;
>
> + if (config->irq_mask) {
> + if (!of_property_read_u32(np, "aspeed,pre-timeout-irq-us", &timeout) && timeout) {
> + int irq = platform_get_irq(pdev, 0);
> +
> + if (irq < 0) {
> + dev_warn(dev, "Couldn't find IRQ: %d\n", irq);
> + timeout = 0;
> + } else {
> + ret = devm_request_irq(dev, irq, aspeed_wdt_irq, IRQF_SHARED,
> + dev_name(dev), wdt);
> + if (ret) {
> + dev_warn(dev, "Couldn't request IRQ:%d\n", ret);
> + timeout = 0;
> + } else {
> + wdt->ctrl |= ((timeout << config->irq_shift) &
> + config->irq_mask) | WDT_CTRL_WDT_INTR;
> + }
> + }
> + }
> + }
> +
> /*
> * Control reset on a per-device basis to ensure the
> * host is not affected by a BMC reboot
> @@ -308,7 +357,7 @@ static int aspeed_wdt_probe(struct platform_device *pdev)
> else if (!strcmp(reset_type, "system"))
> wdt->ctrl |= WDT_CTRL_RESET_MODE_FULL_CHIP |
> WDT_CTRL_RESET_SYSTEM;
> - else if (strcmp(reset_type, "none"))
> + else if (strcmp(reset_type, "none") && !timeout)
> return -EINVAL;
> }
> if (of_property_read_bool(np, "aspeed,external-signal"))
> --
> 2.31.1
>
