On Tue, Aug 23, 2022 at 10:32:33AM +0100, Phil Edworthy wrote:
> The WDT on RZ/V2M devices is basically the same as RZ/G2L, but without
> the parity error registers. This means the driver has to reset the
> hardware plus set the minimum timeout in order to do a restart and has
> a single interrupt.
>
> Signed-off-by: Phil Edworthy <phil.edworthy@xxxxxxxxxxx>
> Reviewed-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ---
> v4:
> - Fix enum names from I2C_* to WDT_*
> - Change cast from of_device_get_match_data() to avoid clang warning
> v3:
> - Don't call pm_runtime_get_sync() in restart()
> - Use mdelay instead of udelay, avoids DIV64_U64_ROUND_UP
> v2:
> - Replace use of parity error registers in restart
> - Commit msg modified to reflect different contents
> ---
> drivers/watchdog/rzg2l_wdt.c | 39 ++++++++++++++++++++++++++++++------
> 1 file changed, 33 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
> index 6eea0ee4af49..974a4194a8fd 100644
> --- a/drivers/watchdog/rzg2l_wdt.c
> +++ b/drivers/watchdog/rzg2l_wdt.c
> @@ -10,7 +10,7 @@
> #include <linux/io.h>
> #include <linux/kernel.h>
> #include <linux/module.h>
> -#include <linux/of.h>
> +#include <linux/of_device.h>
> #include <linux/platform_device.h>
> #include <linux/pm_runtime.h>
> #include <linux/reset.h>
> @@ -40,6 +40,11 @@ module_param(nowayout, bool, 0);
> MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
> __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
>
> +enum rz_wdt_type {
> + WDT_RZG2L,
> + WDT_RZV2M,
> +};
> +
> struct rzg2l_wdt_priv {
> void __iomem *base;
> struct watchdog_device wdev;
> @@ -48,6 +53,7 @@ struct rzg2l_wdt_priv {
> unsigned long delay;
> struct clk *pclk;
> struct clk *osc_clk;
> + enum rz_wdt_type devtype;
> };
>
> static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv)
> @@ -142,11 +148,29 @@ static int rzg2l_wdt_restart(struct watchdog_device *wdev,
> clk_prepare_enable(priv->pclk);
> clk_prepare_enable(priv->osc_clk);
>
> - /* Generate Reset (WDTRSTB) Signal on parity error */
> - rzg2l_wdt_write(priv, 0, PECR);
> + if (priv->devtype == WDT_RZG2L) {
> + /* Generate Reset (WDTRSTB) Signal on parity error */
> + rzg2l_wdt_write(priv, 0, PECR);
> +
> + /* Force parity error */
> + rzg2l_wdt_write(priv, PEEN_FORCE, PEEN);
> + } else {
> + /* RZ/V2M doesn't have parity error registers */
> +
> + wdev->timeout = 0;
> +
> + /* Initialize time out */
> + rzg2l_wdt_init_timeout(wdev);
>
> - /* Force parity error */
> - rzg2l_wdt_write(priv, PEEN_FORCE, PEEN);
> + /* Initialize watchdog counter register */
> + rzg2l_wdt_write(priv, 0, WDTTIM);
> +
> + /* Enable watchdog timer*/
> + rzg2l_wdt_write(priv, WDTCNT_WDTEN, WDTCNT);
> +
> + /* Wait 2 consecutive overflow cycles for reset */
> + mdelay(DIV_ROUND_UP(2 * 0xFFFFF * 1000, priv->osc_clk_rate));
> + }
>
> return 0;
> }
> @@ -227,6 +251,8 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
> if (ret)
> return dev_err_probe(dev, ret, "failed to deassert");
>
> + priv->devtype = (uintptr_t)of_device_get_match_data(dev);
> +
> pm_runtime_enable(&pdev->dev);
>
> priv->wdev.info = &rzg2l_wdt_ident;
> @@ -255,7 +281,8 @@ static int rzg2l_wdt_probe(struct platform_device *pdev)
> }
>
> static const struct of_device_id rzg2l_wdt_ids[] = {
> - { .compatible = "renesas,rzg2l-wdt", },
> + { .compatible = "renesas,rzg2l-wdt", .data = (void *)WDT_RZG2L },
> + { .compatible = "renesas,rzv2m-wdt", .data = (void *)WDT_RZV2M },
> { /* sentinel */ }
> };
> MODULE_DEVICE_TABLE(of, rzg2l_wdt_ids);
