1 /******************************************************************************
3 * Copyright (C) 2010 - 2014 Xilinx, Inc. All rights reserved.
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12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
15 * Use of the Software is limited solely to applications:
16 * (a) running on a Xilinx device, or
17 * (b) that interact with a Xilinx device through a bus or interconnect.
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31 ******************************************************************************/
32 /****************************************************************************/
37 * The Xilinx SCU watchdog timer driver (XScuWdt) supports the Xilinx SCU private
38 * watchdog timer hardware.
40 * The XScuWdt driver supports the following features:
43 * - Auto reload (timer mode only)
45 * The watchdog counter register is a down counter and starts decrementing when
46 * the watchdog is started.
47 * In watchdog mode, when the counter reaches 0, the Reset flag is set in the
48 * Reset status register and the WDRESETREQ pin is asserted, causing a system
49 * reset. The Reset flag is not reset by normal processor reset and is cleared
50 * when written with a value of 1. This enables the user to differentiate a
51 * normal reset and a reset caused by watchdog time-out. The user needs to call
52 * XScuWdt_RestartWdt() periodically, to avoid the watchdog from being timed-out.
54 * The IsWdtExpired function can be used to check if the watchdog was the cause
55 * of the last reset. In this situation, call Initialize then call IsWdtExpired.
56 * If the result is true, watchdog timeout caused the last system reset. The
57 * application then needs to clear the Reset flag.
59 * In timer mode, when the counter reaches 0, the Event flag is set in the
60 * Interrupt status register and if interrupts are enabled, interrupt ID 30 is
61 * set as pending in the interrupt distributor. The IsTimerExpired function
62 * is used to check if the watchdog counter has decremented to 0 in timer mode.
63 * If auto-reload mode is enabled, the Counter register is automatically reloaded
64 * from the Load register.
66 * <b> Initialization and Configuration </b>
68 * The device driver enables higher layer software (e.g., an application) to
69 * communicate with the Watchdog Timer.
71 * XScuWdt_CfgInitialize() API is used to initialize the Watchdog Timer. The
72 * user needs to first call the XScuWdt_LookupConfig() API which returns
73 * the Configuration structure pointer which is passed as a parameter to
74 * the XScuWdt_CfgInitialize() API.
78 * The SCU Watchdog Timer supports interrupts in Timer mode.
80 * This driver does not provide a Interrupt Service Routine (ISR) for the device.
81 * It is the responsibility of the application to provide one if needed. Refer to
82 * the interrupt example provided with this driver for details on using the
83 * Timer in interrupt mode.
85 * <b> Virtual Memory </b>
87 * This driver supports Virtual Memory. The RTOS is responsible for calculating
88 * the correct device base address in Virtual Memory space.
92 * This driver is not thread safe. Any needs for threads or thread mutual
93 * exclusion must be satisfied by the layer above this driver.
97 * Asserts are used within all Xilinx drivers to enforce constraints on argument
98 * values. Asserts can be turned off on a system-wide basis by defining, at
99 * compile time, the NDEBUG identifier. By default, asserts are turned on and it
100 * is recommended that users leave asserts on during development.
102 * <b> Building the driver </b>
104 * The XScuWdt driver is composed of several source files. This allows the user
105 * to build and link only those parts of the driver that are necessary.
110 * The watchdog timer is not a part of the snoop control unit as indicated
111 * by the prefix "scu" in the name of the driver.
112 * It is an independent module in APU.
115 * MODIFICATION HISTORY:
117 * Ver Who Date Changes
118 * ----- --- -------- ---------------------------------------------
119 * 1.00a sdm 01/15/10 First release
120 * 1.02a sg 07/17/12 Included xil_assert.h for CR 667947. This is an issue
121 * when the xstatus.h in the common driver overwrites
122 * the xstatus.h of the standalone BSP during the
126 ******************************************************************************/
127 #ifndef XSCUWDT_H /* prevent circular inclusions */
128 #define XSCUWDT_H /* by using protection macros */
130 /***************************** Include Files *********************************/
133 #include "xscuwdt_hw.h"
139 /************************** Constant Definitions *****************************/
141 /**************************** Type Definitions *******************************/
144 * This typedef contains configuration information for the device.
147 u16 DeviceId; /**< Unique ID of device */
148 u32 BaseAddr; /**< Base address of the device */
152 * The XScuWdt driver instance data. The user is required to allocate a
153 * variable of this type for every watchdog/timer device in the system.
154 * A pointer to a variable of this type is then passed to the driver API
158 XScuWdt_Config Config;/**< Hardware Configuration */
159 u32 IsReady; /**< Device is initialized and ready */
160 u32 IsStarted; /**< Device watchdog timer is running */
163 /***************** Macros (Inline Functions) Definitions *********************/
164 /****************************************************************************/
167 * This function is used to check if the watchdog has timed-out and the last
168 * reset was caused by the watchdog reset.
170 * @param InstancePtr is a pointer to the XScuWdt instance.
173 * - TRUE if the watchdog has expired.
174 * - FALSE if the watchdog has not expired.
176 * @note C-style signature:
177 * int XScuWdt_IsWdtExpired(XScuWdt *InstancePtr)
179 ******************************************************************************/
180 #define XScuWdt_IsWdtExpired(InstancePtr) \
181 ((XScuWdt_ReadReg((InstancePtr)->Config.BaseAddr, \
182 XSCUWDT_RST_STS_OFFSET) & \
183 XSCUWDT_RST_STS_RESET_FLAG_MASK) == XSCUWDT_RST_STS_RESET_FLAG_MASK)
185 /****************************************************************************/
188 * This function is used to check if the watchdog counter has reached 0 in timer
191 * @param InstancePtr is a pointer to the XScuWdt instance.
194 * - TRUE if the watchdog has expired.
195 * - FALSE if the watchdog has not expired.
197 * @note C-style signature:
198 * int XScuWdt_IsTimerExpired(XScuWdt *InstancePtr)
200 ******************************************************************************/
201 #define XScuWdt_IsTimerExpired(InstancePtr) \
202 ((XScuWdt_ReadReg((InstancePtr)->Config.BaseAddr, \
203 XSCUWDT_ISR_OFFSET) & \
204 XSCUWDT_ISR_EVENT_FLAG_MASK) == XSCUWDT_ISR_EVENT_FLAG_MASK)
206 /****************************************************************************/
209 * Re-start the watchdog timer. This macro will read the watchdog load register
210 * and write the same value to load register to update the counter register.
211 * An application needs to call this function periodically to keep the watchdog
212 * from asserting the WDRESETREQ reset request output pin.
214 * @param InstancePtr is a pointer to the XScuWdt instance.
218 * @note C-style signature:
219 * void XScuWdt_RestartWdt(XScuWdt *InstancePtr)
221 ******************************************************************************/
222 #define XScuWdt_RestartWdt(InstancePtr) \
223 XScuWdt_LoadWdt(InstancePtr, \
224 (XScuWdt_ReadReg((InstancePtr)->Config.BaseAddr, \
225 XSCUWDT_LOAD_OFFSET)))
227 /****************************************************************************/
230 * Write to the watchdog timer load register. This will also update the
231 * watchdog counter register with the new value. This macro can be used to
232 * change the time-out value.
234 * @param InstancePtr is a pointer to the XScuWdt instance.
235 * @param Value is the value to be written to the Watchdog Load register.
239 * @note C-style signature:
240 * void XScuWdt_LoadWdt(XScuWdt *InstancePtr, u32 Value)
242 ******************************************************************************/
243 #define XScuWdt_LoadWdt(InstancePtr, Value) \
244 XScuWdt_WriteReg((InstancePtr)->Config.BaseAddr, \
245 XSCUWDT_LOAD_OFFSET, Value)
247 /****************************************************************************/
250 * Put the watchdog timer in Watchdog mode by setting the WD mode bit of the
251 * Watchdog control register.
253 * @param InstancePtr is a pointer to the XScuWdt instance.
257 * @note C-style signature:
258 * void XScuWdt_SetWdMode(XScuWdt *InstancePtr)
260 ******************************************************************************/
261 #define XScuWdt_SetWdMode(InstancePtr) \
262 XScuWdt_WriteReg((InstancePtr)->Config.BaseAddr, \
263 XSCUWDT_CONTROL_OFFSET, \
264 (XScuWdt_ReadReg((InstancePtr)->Config.BaseAddr, \
265 XSCUWDT_CONTROL_OFFSET) | \
266 XSCUWDT_CONTROL_WD_MODE_MASK))
268 /****************************************************************************/
271 * Put the watchdog timer in Timer mode by writing 0x12345678 and 0x87654321
272 * successively to the Watchdog Disable Register.
273 * The software must write 0x12345678 and 0x87654321 successively to the
274 * Watchdog Disable Register so that the watchdog mode bit in the Watchdog
275 * Control Register is set to zero.
277 * @param InstancePtr is a pointer to the XScuWdt instance.
281 * @note C-style signature:
282 * void XScuWdt_SetTimerMode(XScuWdt *InstancePtr)
284 ******************************************************************************/
285 #define XScuWdt_SetTimerMode(InstancePtr) \
287 XScuWdt_WriteReg((InstancePtr)->Config.BaseAddr, \
288 XSCUWDT_DISABLE_OFFSET, \
289 XSCUWDT_DISABLE_VALUE1); \
290 XScuWdt_WriteReg((InstancePtr)->Config.BaseAddr, \
291 XSCUWDT_DISABLE_OFFSET, \
292 XSCUWDT_DISABLE_VALUE2); \
295 /****************************************************************************/
298 * Get the contents of the watchdog control register.
300 * @param InstancePtr is a pointer to the XScuWdt instance.
302 * @return Contents of the watchdog control register.
304 * @note C-style signature:
305 u32 XScuWdt_GetControlReg(XScuWdt *InstancePtr)
307 ******************************************************************************/
308 #define XScuWdt_GetControlReg(InstancePtr) \
309 XScuWdt_ReadReg((InstancePtr)->Config.BaseAddr, \
310 XSCUWDT_CONTROL_OFFSET)
312 /****************************************************************************/
315 * Write to the watchdog control register.
317 * @param InstancePtr is a pointer to the XScuWdt instance.
318 * @param ControlReg is the value to be written to the watchdog control
323 * @note C-style signature:
324 void XScuWdt_SetControlReg(XScuWdt *InstancePtr, u32 ControlReg)
326 ******************************************************************************/
327 #define XScuWdt_SetControlReg(InstancePtr, ControlReg) \
328 XScuWdt_WriteReg((InstancePtr)->Config.BaseAddr, \
329 XSCUWDT_CONTROL_OFFSET, ControlReg)
331 /****************************************************************************/
334 * Enable auto-reload mode.
336 * @param InstancePtr is a pointer to the XScuWdt instance.
340 * @note C-style signature:
341 * void XScuWdt_EnableAutoReload(XScuWdt *InstancePtr)
343 ******************************************************************************/
344 #define XScuWdt_EnableAutoReload(InstancePtr) \
345 XScuWdt_SetControlReg((InstancePtr), \
346 (XScuWdt_GetControlReg(InstancePtr) | \
347 XSCUWDT_CONTROL_AUTO_RELOAD_MASK))
349 /************************** Function Prototypes ******************************/
352 * Lookup configuration in xscuwdt_sinit.c.
354 XScuWdt_Config *XScuWdt_LookupConfig(u16 DeviceId);
357 * Selftest function in xscuwdt_selftest.c
359 int XScuWdt_SelfTest(XScuWdt *InstancePtr);
362 * Interface functions in xscuwdt.c
364 int XScuWdt_CfgInitialize(XScuWdt *InstancePtr,
365 XScuWdt_Config *ConfigPtr, u32 EffectiveAddress);
367 void XScuWdt_Start(XScuWdt *InstancePtr);
369 void XScuWdt_Stop(XScuWdt *InstancePtr);
372 * Self-test function in xwdttb_selftest.c.
374 int XScuWdt_SelfTest(XScuWdt *InstancePtr);
380 #endif /* end of protection macro */