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31 ******************************************************************************/
32 /*****************************************************************************/
36 * @addtogroup iicps_v2_1
39 * Contains implementation of required functions for the XIicPs driver.
40 * See xiicps.h for detailed description of the device and driver.
42 * <pre> MODIFICATION HISTORY:
44 * Ver Who Date Changes
45 * ----- ------ -------- --------------------------------------------
46 * 1.00a drg/jz 01/30/10 First release
47 * 1.00a sdm 09/21/11 Updated the InstancePtr->Options in the
48 * XIicPs_CfgInitialize by calling XIicPs_GetOptions.
49 * 2.1 hk 04/25/14 Explicitly reset CR and clear FIFO in Abort function
50 * and state the same in the comments. CR# 784254.
51 * Fix for CR# 761060 - provision for repeated start.
55 ******************************************************************************/
57 /***************************** Include Files *********************************/
61 /************************** Constant Definitions *****************************/
63 /**************************** Type Definitions *******************************/
65 /***************** Macros (Inline Functions) Definitions *********************/
67 /************************** Function Prototypes ******************************/
69 static void StubHandler(void *CallBackRef, u32 StatusEvent);
71 /************************** Variable Definitions *****************************/
74 /*****************************************************************************/
77 * Initializes a specific XIicPs instance such that the driver is ready to use.
79 * The state of the device after initialization is:
80 * - Device is disabled
83 * @param InstancePtr is a pointer to the XIicPs instance.
84 * @param ConfigPtr is a reference to a structure containing information
85 * about a specific IIC device. This function initializes an
86 * InstancePtr object for a specific device specified by the
88 * @param EffectiveAddr is the device base address in the virtual memory
89 * address space. The caller is responsible for keeping the address
90 * mapping from EffectiveAddr to the device physical base address
91 * unchanged once this function is invoked. Unexpected errors may
92 * occur if the address mapping changes after this function is
93 * called. If address translation is not used, use
94 * ConfigPtr->BaseAddress for this parameter, passing the physical
97 * @return The return value is XST_SUCCESS if successful.
101 ******************************************************************************/
102 int XIicPs_CfgInitialize(XIicPs *InstancePtr, XIicPs_Config *ConfigPtr,
106 * Assert validates the input arguments.
108 Xil_AssertNonvoid(InstancePtr != NULL);
109 Xil_AssertNonvoid(ConfigPtr != NULL);
112 * Set some default values.
114 InstancePtr->Config.DeviceId = ConfigPtr->DeviceId;
115 InstancePtr->Config.BaseAddress = EffectiveAddr;
116 InstancePtr->Config.InputClockHz = ConfigPtr->InputClockHz;
117 InstancePtr->StatusHandler = StubHandler;
118 InstancePtr->CallBackRef = NULL;
120 InstancePtr->IsReady = XIL_COMPONENT_IS_READY;
123 * Reset the IIC device to get it into its initial state. It is expected
124 * that device configuration will take place after this initialization
125 * is done, but before the device is started.
127 XIicPs_Reset(InstancePtr);
130 * Keep a copy of what options this instance has.
132 InstancePtr->Options = XIicPs_GetOptions(InstancePtr);
134 /* Initialize repeated start flag to 0 */
135 InstancePtr->IsRepeatedStart = 0;
140 /*****************************************************************************/
142 * Check whether the I2C bus is busy
144 * @param InstancePtr is a pointer to the XIicPs instance.
147 * - TRUE if the bus is busy.
148 * - FALSE if the bus is not busy.
152 ******************************************************************************/
153 int XIicPs_BusIsBusy(XIicPs *InstancePtr)
157 StatusReg = XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
159 if (StatusReg & XIICPS_SR_BA_MASK) {
166 /*****************************************************************************/
169 * This is a stub for the status callback. The stub is here in case the upper
170 * layers forget to set the handler.
172 * @param CallBackRef is a pointer to the upper layer callback reference.
173 * @param StatusEvent is the event that just occurred.
174 * @param ByteCount is the number of bytes transferred up until the event
181 ******************************************************************************/
182 static void StubHandler(void *CallBackRef, u32 StatusEvent)
186 Xil_AssertVoidAlways();
190 /*****************************************************************************/
193 * Aborts a transfer in progress by resetting the FIFOs. The byte counts are
196 * @param InstancePtr is a pointer to the XIicPs instance.
202 ******************************************************************************/
203 void XIicPs_Abort(XIicPs *InstancePtr)
208 Xil_AssertVoid(InstancePtr != NULL);
209 Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
212 * Enter a critical section, so disable the interrupts while we clear
213 * the FIFO and the status register.
215 IntrMaskReg = XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
217 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
218 XIICPS_IDR_OFFSET, XIICPS_IXR_ALL_INTR_MASK);
221 * Reset the settings in config register and clear the FIFOs.
223 XIicPs_WriteReg(InstancePtr->Config.BaseAddress, XIICPS_CR_OFFSET,
224 XIICPS_CR_RESET_VALUE | XIICPS_CR_CLR_FIFO_MASK);
227 * Read, then write the interrupt status to make sure there are no
228 * pending interrupts.
230 IntrStatusReg = XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
232 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
233 XIICPS_ISR_OFFSET, IntrStatusReg);
236 * Restore the interrupt state.
238 IntrMaskReg = XIICPS_IXR_ALL_INTR_MASK & (~IntrMaskReg);
239 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
240 XIICPS_IER_OFFSET, IntrMaskReg);
244 /*****************************************************************************/
247 * Resets the IIC device. Reset must only be called after the driver has been
248 * initialized. The configuration of the device after reset is the same as its
249 * configuration after initialization. Any data transfer that is in progress is
252 * The upper layer software is responsible for re-configuring (if necessary)
253 * and reenabling interrupts for the IIC device after the reset.
255 * @param InstancePtr is a pointer to the XIicPs instance.
261 ******************************************************************************/
262 void XIicPs_Reset(XIicPs *InstancePtr)
265 Xil_AssertVoid(InstancePtr != NULL);
266 Xil_AssertVoid(InstancePtr->IsReady == XIL_COMPONENT_IS_READY);
269 * Abort any transfer that is in progress.
271 XIicPs_Abort(InstancePtr);
274 * Reset any values so the software state matches the hardware device.
276 XIicPs_WriteReg(InstancePtr->Config.BaseAddress, XIICPS_CR_OFFSET,
277 XIICPS_CR_RESET_VALUE);
278 XIicPs_WriteReg(InstancePtr->Config.BaseAddress,
279 XIICPS_TIME_OUT_OFFSET, XIICPS_TO_RESET_VALUE);
280 XIicPs_WriteReg(InstancePtr->Config.BaseAddress, XIICPS_IDR_OFFSET,
281 XIICPS_IXR_ALL_INTR_MASK);
284 /*****************************************************************************/
286 * Put more data into the transmit FIFO, number of bytes is ether expected
287 * number of bytes for this transfer or available space in FIFO, which ever
290 * @param InstancePtr is a pointer to the XIicPs instance.
292 * @return Number of bytes left for this instance.
294 * @note This is function is shared by master and slave.
296 ******************************************************************************/
297 int TransmitFifoFill(XIicPs *InstancePtr)
304 * Determine number of bytes to write to FIFO.
306 AvailBytes = XIICPS_FIFO_DEPTH -
307 XIicPs_ReadReg(InstancePtr->Config.BaseAddress,
308 XIICPS_TRANS_SIZE_OFFSET);
310 if (InstancePtr->SendByteCount > AvailBytes) {
311 NumBytesToSend = AvailBytes;
313 NumBytesToSend = InstancePtr->SendByteCount;
317 * Fill FIFO with amount determined above.
319 for (LoopCnt = 0; LoopCnt < NumBytesToSend; LoopCnt++) {
320 XIicPs_SendByte(InstancePtr);
323 return InstancePtr->SendByteCount;