diff options
author | Alice Guo <alice.guo@nxp.com> | 2022-08-25 16:32:56 +0800 |
---|---|---|
committer | Wim Van Sebroeck <wim@linux-watchdog.org> | 2022-10-02 12:55:47 +0200 |
commit | 8ed2dc48551354bbf33df869f3968b7805cbaa61 (patch) | |
tree | 2c4597c548f067a49963ae442bbf70c7234c8151 /drivers | |
parent | cef6bc98d50da24252fb289759f1790e17afa448 (diff) | |
download | linux-8ed2dc48551354bbf33df869f3968b7805cbaa61.tar.gz linux-8ed2dc48551354bbf33df869f3968b7805cbaa61.tar.bz2 linux-8ed2dc48551354bbf33df869f3968b7805cbaa61.zip |
watchdog: imx93: add watchdog timer on imx93
The WDOG clocks are sourced from lpo_clk, and lpo_clk is the fixed
32KHz. TOVAL contains the 16-bit value used to set the timeout period of
the watchdog. When the timeout period exceeds 2 seconds, the value
written to the TOVAL register is larger than 16-bit can represent.
Enabling watchdog prescaler can solve this problem.
Two points need to be aware of:
1. watchdog prescaler enables a fixed 256 pre-scaling of watchdog
counter reference clock
2. reconfiguration takes about 55ms on imx93
Reviewed-by: Jacky Bai <ping.bai@nxp.com>
Signed-off-by: Alice Guo <alice.guo@nxp.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20220825083256.14565-8-alice.guo@oss.nxp.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/watchdog/imx7ulp_wdt.c | 33 |
1 files changed, 28 insertions, 5 deletions
diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c index dee02c2a52c9..2897902090b3 100644 --- a/drivers/watchdog/imx7ulp_wdt.c +++ b/drivers/watchdog/imx7ulp_wdt.c @@ -9,6 +9,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_device.h> #include <linux/platform_device.h> #include <linux/reboot.h> #include <linux/watchdog.h> @@ -52,11 +53,17 @@ module_param(nowayout, bool, 0000); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +struct imx_wdt_hw_feature { + bool prescaler_enable; + u32 wdog_clock_rate; +}; + struct imx7ulp_wdt_device { struct watchdog_device wdd; void __iomem *base; struct clk *clk; bool post_rcs_wait; + const struct imx_wdt_hw_feature *hw; }; static int imx7ulp_wdt_wait_ulk(void __iomem *base) @@ -179,7 +186,7 @@ static int imx7ulp_wdt_set_timeout(struct watchdog_device *wdog, unsigned int timeout) { struct imx7ulp_wdt_device *wdt = watchdog_get_drvdata(wdog); - u32 toval = WDOG_CLOCK_RATE * timeout; + u32 toval = wdt->hw->wdog_clock_rate * timeout; u32 val; int ret; u32 loop = RETRY_MAX; @@ -276,6 +283,9 @@ static int imx7ulp_wdt_init(struct imx7ulp_wdt_device *wdt, unsigned int timeout int ret; u32 loop = RETRY_MAX; + if (wdt->hw->prescaler_enable) + val |= WDOG_CS_PRES; + do { ret = _imx7ulp_wdt_init(wdt, timeout, val); toval = readl(wdt->base + WDOG_TOVAL); @@ -346,7 +356,9 @@ static int imx7ulp_wdt_probe(struct platform_device *pdev) watchdog_stop_on_reboot(wdog); watchdog_stop_on_unregister(wdog); watchdog_set_drvdata(wdog, imx7ulp_wdt); - ret = imx7ulp_wdt_init(imx7ulp_wdt, wdog->timeout * WDOG_CLOCK_RATE); + + imx7ulp_wdt->hw = of_device_get_match_data(dev); + ret = imx7ulp_wdt_init(imx7ulp_wdt, wdog->timeout * imx7ulp_wdt->hw->wdog_clock_rate); if (ret) return ret; @@ -368,7 +380,7 @@ static int __maybe_unused imx7ulp_wdt_suspend_noirq(struct device *dev) static int __maybe_unused imx7ulp_wdt_resume_noirq(struct device *dev) { struct imx7ulp_wdt_device *imx7ulp_wdt = dev_get_drvdata(dev); - u32 timeout = imx7ulp_wdt->wdd.timeout * WDOG_CLOCK_RATE; + u32 timeout = imx7ulp_wdt->wdd.timeout * imx7ulp_wdt->hw->wdog_clock_rate; int ret; ret = clk_prepare_enable(imx7ulp_wdt->clk); @@ -389,9 +401,20 @@ static const struct dev_pm_ops imx7ulp_wdt_pm_ops = { imx7ulp_wdt_resume_noirq) }; +static const struct imx_wdt_hw_feature imx7ulp_wdt_hw = { + .prescaler_enable = false, + .wdog_clock_rate = 1000, +}; + +static const struct imx_wdt_hw_feature imx93_wdt_hw = { + .prescaler_enable = true, + .wdog_clock_rate = 125, +}; + static const struct of_device_id imx7ulp_wdt_dt_ids[] = { - { .compatible = "fsl,imx8ulp-wdt", }, - { .compatible = "fsl,imx7ulp-wdt", }, + { .compatible = "fsl,imx8ulp-wdt", .data = &imx7ulp_wdt_hw, }, + { .compatible = "fsl,imx7ulp-wdt", .data = &imx7ulp_wdt_hw, }, + { .compatible = "fsl,imx93-wdt", .data = &imx93_wdt_hw, }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, imx7ulp_wdt_dt_ids); |