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31 ******************************************************************************/
32 /*****************************************************************************/
37 * Contains implementation of required functions for the XIicPs driver.
38 * See xiicps.h for detailed description of the device and driver.
40 * <pre> MODIFICATION HISTORY:
42 * Ver Who Date Changes
43 * ----- ------ -------- --------------------------------------------
44 * 1.00a drg/jz 01/30/10 First release
45 * 1.00a sdm 09/21/11 Updated the InstancePtr->Options in the
46 * XIicPs_CfgInitialize by calling XIicPs_GetOptions.
47 * 2.1 hk 04/25/14 Explicitly reset CR and clear FIFO in Abort function
48 * and state the same in the comments. CR# 784254.
49 * Fix for CR# 761060 - provision for repeated start.
53 ******************************************************************************/
55 /***************************** Include Files *********************************/
59 /************************** Constant Definitions *****************************/
61 /**************************** Type Definitions *******************************/
63 /***************** Macros (Inline Functions) Definitions *********************/
65 /************************** Function Prototypes ******************************/
67 static void StubHandler(void *CallBackRef, u32 StatusEvent);
69 /************************** Variable Definitions *****************************/
72 /*****************************************************************************/
75 * Initializes a specific XIicPs instance such that the driver is ready to use.
77 * The state of the device after initialization is:
78 * - Device is disabled
81 * @param InstancePtr is a pointer to the XIicPs instance.
82 * @param ConfigPtr is a reference to a structure containing information
83 * about a specific IIC device. This function initializes an
84 * InstancePtr object for a specific device specified by the
86 * @param EffectiveAddr is the device base address in the virtual memory
87 * address space. The caller is responsible for keeping the address
88 * mapping from EffectiveAddr to the device physical base address
89 * unchanged once this function is invoked. Unexpected errors may
90 * occur if the address mapping changes after this function is
91 * called. If address translation is not used, use
92 * ConfigPtr->BaseAddress for this parameter, passing the physical
95 * @return The return value is XST_SUCCESS if successful.
99 ******************************************************************************/
100 int XIicPs_CfgInitialize(XIicPs *InstancePtr, XIicPs_Config *ConfigPtr,
104 * Assert validates the input arguments.
106 Xil_AssertNonvoid(InstancePtr != NULL);
107 Xil_AssertNonvoid(ConfigPtr != NULL);
110 * Set some default values.
112 InstancePtr->Config.DeviceId = ConfigPtr->DeviceId;
113 InstancePtr->Config.BaseAddress = EffectiveAddr;
114 InstancePtr->Config.InputClockHz = ConfigPtr->InputClockHz;
115 InstancePtr->StatusHandler = StubHandler;
116 InstancePtr->CallBackRef = NULL;
118 InstancePtr->IsReady = XIL_COMPONENT_IS_READY;
121 * Reset the IIC device to get it into its initial state. It is expected
122 * that device configuration will take place after this initialization
123 * is done, but before the device is started.
125 XIicPs_Reset(InstancePtr);
128 * Keep a copy of what options this instance has.
130 InstancePtr->Options = XIicPs_GetOptions(InstancePtr);
132 /* Initialize repeated start flag to 0 */
133 InstancePtr->IsRepeatedStart = 0;
138 /*****************************************************************************/
140 * Check whether the I2C bus is busy
142 * @param InstancePtr is a pointer to the XIicPs instance.
145 * - TRUE if the bus is busy.
146 * - FALSE if the bus is not busy.
150 ******************************************************************************/
151 int XIicPs_BusIsBusy(XIicPs *InstancePtr)
155 StatusReg = XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
157 if (StatusReg & XIICPS_SR_BA_MASK) {
164 /*****************************************************************************/
167 * This is a stub for the status callback. The stub is here in case the upper
168 * layers forget to set the handler.
170 * @param CallBackRef is a pointer to the upper layer callback reference.
171 * @param StatusEvent is the event that just occurred.
172 * @param ByteCount is the number of bytes transferred up until the event
179 ******************************************************************************/
180 static void StubHandler(void *CallBackRef, u32 StatusEvent)
184 Xil_AssertVoidAlways();
188 /*****************************************************************************/
191 * Aborts a transfer in progress by resetting the FIFOs. The byte counts are
194 * @param InstancePtr is a pointer to the XIicPs instance.
200 ******************************************************************************/
201 void XIicPs_Abort(XIicPs *InstancePtr)
206 Xil_AssertVoid(InstancePtr != NULL);
207 Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
210 * Enter a critical section, so disable the interrupts while we clear
211 * the FIFO and the status register.
213 IntrMaskReg = XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
215 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
216 XIICPS_IDR_OFFSET, XIICPS_IXR_ALL_INTR_MASK);
219 * Reset the settings in config register and clear the FIFOs.
221 XIicPs_WriteReg(InstancePtr->Config.BaseAddress, XIICPS_CR_OFFSET,
222 XIICPS_CR_RESET_VALUE | XIICPS_CR_CLR_FIFO_MASK);
225 * Read, then write the interrupt status to make sure there are no
226 * pending interrupts.
228 IntrStatusReg = XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
230 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
231 XIICPS_ISR_OFFSET, IntrStatusReg);
234 * Restore the interrupt state.
236 IntrMaskReg = XIICPS_IXR_ALL_INTR_MASK & (~IntrMaskReg);
237 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
238 XIICPS_IER_OFFSET, IntrMaskReg);
242 /*****************************************************************************/
245 * Resets the IIC device. Reset must only be called after the driver has been
246 * initialized. The configuration of the device after reset is the same as its
247 * configuration after initialization. Any data transfer that is in progress is
250 * The upper layer software is responsible for re-configuring (if necessary)
251 * and reenabling interrupts for the IIC device after the reset.
253 * @param InstancePtr is a pointer to the XIicPs instance.
259 ******************************************************************************/
260 void XIicPs_Reset(XIicPs *InstancePtr)
263 Xil_AssertVoid(InstancePtr != NULL);
264 Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
267 * Abort any transfer that is in progress.
269 XIicPs_Abort(InstancePtr);
272 * Reset any values so the software state matches the hardware device.
274 XIicPs_WriteReg(InstancePtr->Config.BaseAddress, XIICPS_CR_OFFSET,
275 XIICPS_CR_RESET_VALUE);
276 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
277 XIICPS_TIME_OUT_OFFSET, XIICPS_TO_RESET_VALUE);
278 XIicPs_WriteReg(InstancePtr->Config.BaseAddress, XIICPS_IDR_OFFSET,
279 XIICPS_IXR_ALL_INTR_MASK);
282 /*****************************************************************************/
284 * Put more data into the transmit FIFO, number of bytes is ether expected
285 * number of bytes for this transfer or available space in FIFO, which ever
288 * @param InstancePtr is a pointer to the XIicPs instance.
290 * @return Number of bytes left for this instance.
292 * @note This is function is shared by master and slave.
294 ******************************************************************************/
295 int TransmitFifoFill(XIicPs *InstancePtr)
302 * Determine number of bytes to write to FIFO.
304 AvailBytes = XIICPS_FIFO_DEPTH -
305 XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
306 XIICPS_TRANS_SIZE_OFFSET);
308 if (InstancePtr->SendByteCount > AvailBytes) {
309 NumBytesToSend = AvailBytes;
311 NumBytesToSend = InstancePtr->SendByteCount;
315 * Fill FIFO with amount determined above.
317 for (LoopCnt = 0; LoopCnt < NumBytesToSend; LoopCnt++) {
318 XIicPs_SendByte(InstancePtr);
321 return InstancePtr->SendByteCount;