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authorAlbrecht Dreß <albrecht.dress@arcor.de>2009-11-13 13:09:30 -0500
committerGrant Likely <grant.likely@secretlab.ca>2009-11-13 13:09:30 -0500
commit13b600b59df287a175b1476d2d588ab935092b58 (patch)
treebca214b840b7260e27b3be1df45e7af4a8e9ba38 /Documentation/powerpc/dts-bindings
parent690b846aa1b42b4f35bfac0022b75a288d97fd13 (diff)
mpc52xx/wdt: OF property to enable the WDT on boot
Add the "fsl,wdt-on-boot" OF property as to reserve a GPT as WDT which may be a requirement in safety-related (e.g. ISO/EN 61508) applications. Signed-off-by: Albrecht Dreß <albrecht.dress@arcor.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'Documentation/powerpc/dts-bindings')
-rw-r--r--Documentation/powerpc/dts-bindings/fsl/mpc5200.txt17
1 files changed, 16 insertions, 1 deletions
diff --git a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
index 8447fd7090d0..ddd5ee32ea63 100644
--- a/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
+++ b/Documentation/powerpc/dts-bindings/fsl/mpc5200.txt
@@ -103,7 +103,22 @@ fsl,mpc5200-gpt nodes
103--------------------- 103---------------------
104On the mpc5200 and 5200b, GPT0 has a watchdog timer function. If the board 104On the mpc5200 and 5200b, GPT0 has a watchdog timer function. If the board
105design supports the internal wdt, then the device node for GPT0 should 105design supports the internal wdt, then the device node for GPT0 should
106include the empty property 'fsl,has-wdt'. 106include the empty property 'fsl,has-wdt'. Note that this does not activate
107the watchdog. The timer will function as a GPT if the timer api is used, and
108it will function as watchdog if the watchdog device is used. The watchdog
109mode has priority over the gpt mode, i.e. if the watchdog is activated, any
110gpt api call to this timer will fail with -EBUSY.
111
112If you add the property
113 fsl,wdt-on-boot = <n>;
114GPT0 will be marked as in-use watchdog, i.e. blocking every gpt access to it.
115If n>0, the watchdog is started with a timeout of n seconds. If n=0, the
116configuration of the watchdog is not touched. This is useful in two cases:
117- just mark GPT0 as watchdog, blocking gpt accesses, and configure it later;
118- do not touch a configuration assigned by the boot loader which supervises
119 the boot process itself.
120
121The watchdog will respect the CONFIG_WATCHDOG_NOWAYOUT option.
107 122
108An mpc5200-gpt can be used as a single line GPIO controller. To do so, 123An mpc5200-gpt can be used as a single line GPIO controller. To do so,
109add the following properties to the gpt node: 124add the following properties to the gpt node: