1 /******************************************************************************
2 * Filename: ssi.c
3 * Revised: 2017-04-26 18:27:45 +0200 (Wed, 26 Apr 2017)
4 * Revision: 48852
5 *
6 * Description: Driver for Synchronous Serial Interface
7 *
8 * Copyright (c) 2015 - 2017, Texas Instruments Incorporated
9 * All rights reserved.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions are met:
13 *
14 * 1) Redistributions of source code must retain the above copyright notice,
15 * this list of conditions and the following disclaimer.
16 *
17 * 2) Redistributions in binary form must reproduce the above copyright notice,
18 * this list of conditions and the following disclaimer in the documentation
19 * and/or other materials provided with the distribution.
20 *
21 * 3) Neither the name of the ORGANIZATION nor the names of its contributors may
22 * be used to endorse or promote products derived from this software without
23 * specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
26 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
29 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 *
37 ******************************************************************************/
38
39 #include "ssi.h"
40
41 //*****************************************************************************
42 //
43 // Handle support for DriverLib in ROM:
44 // This section will undo prototype renaming made in the header file
45 //
46 //*****************************************************************************
47 #if !defined(DOXYGEN)
48 #undef SSIConfigSetExpClk
49 #define SSIConfigSetExpClk NOROM_SSIConfigSetExpClk
50 #undef SSIDataPut
51 #define SSIDataPut NOROM_SSIDataPut
52 #undef SSIDataPutNonBlocking
53 #define SSIDataPutNonBlocking NOROM_SSIDataPutNonBlocking
54 #undef SSIDataGet
55 #define SSIDataGet NOROM_SSIDataGet
56 #undef SSIDataGetNonBlocking
57 #define SSIDataGetNonBlocking NOROM_SSIDataGetNonBlocking
58 #undef SSIIntRegister
59 #define SSIIntRegister NOROM_SSIIntRegister
60 #undef SSIIntUnregister
61 #define SSIIntUnregister NOROM_SSIIntUnregister
62 #endif
63
64 //*****************************************************************************
65 //
66 // Configures the synchronous serial port
67 //
68 //*****************************************************************************
69 void
SSIConfigSetExpClk(uint32_t ui32Base,uint32_t ui32SSIClk,uint32_t ui32Protocol,uint32_t ui32Mode,uint32_t ui32BitRate,uint32_t ui32DataWidth)70 SSIConfigSetExpClk(uint32_t ui32Base, uint32_t ui32SSIClk,
71 uint32_t ui32Protocol, uint32_t ui32Mode,
72 uint32_t ui32BitRate, uint32_t ui32DataWidth)
73 {
74 uint32_t ui32MaxBitRate;
75 uint32_t ui32RegVal;
76 uint32_t ui32PreDiv;
77 uint32_t ui32SCR;
78 uint32_t ui32SPH_SPO;
79
80 // Check the arguments.
81 ASSERT(SSIBaseValid(ui32Base));
82 ASSERT((ui32Protocol == SSI_FRF_MOTO_MODE_0) ||
83 (ui32Protocol == SSI_FRF_MOTO_MODE_1) ||
84 (ui32Protocol == SSI_FRF_MOTO_MODE_2) ||
85 (ui32Protocol == SSI_FRF_MOTO_MODE_3) ||
86 (ui32Protocol == SSI_FRF_TI) ||
87 (ui32Protocol == SSI_FRF_NMW));
88 ASSERT((ui32Mode == SSI_MODE_MASTER) ||
89 (ui32Mode == SSI_MODE_SLAVE) ||
90 (ui32Mode == SSI_MODE_SLAVE_OD));
91 ASSERT(((ui32Mode == SSI_MODE_MASTER) && (ui32BitRate <= (ui32SSIClk / 2))) ||
92 ((ui32Mode != SSI_MODE_MASTER) && (ui32BitRate <= (ui32SSIClk / 12))));
93 ASSERT((ui32SSIClk / ui32BitRate) <= (254 * 256));
94 ASSERT((ui32DataWidth >= 4) && (ui32DataWidth <= 16));
95
96 // Set the mode.
97 ui32RegVal = (ui32Mode == SSI_MODE_SLAVE_OD) ? SSI_CR1_SOD : 0;
98 ui32RegVal |= (ui32Mode == SSI_MODE_MASTER) ? 0 : SSI_CR1_MS;
99 HWREG(ui32Base + SSI_O_CR1) = ui32RegVal;
100
101 // Set the clock predivider.
102 ui32MaxBitRate = ui32SSIClk / ui32BitRate;
103 ui32PreDiv = 0;
104 do
105 {
106 ui32PreDiv += 2;
107 ui32SCR = (ui32MaxBitRate / ui32PreDiv) - 1;
108 }
109 while(ui32SCR > 255);
110 HWREG(ui32Base + SSI_O_CPSR) = ui32PreDiv;
111
112 // Set protocol and clock rate.
113 ui32SPH_SPO = (ui32Protocol & 3) << 6;
114 ui32Protocol &= SSI_CR0_FRF_M;
115 ui32RegVal = (ui32SCR << 8) | ui32SPH_SPO | ui32Protocol | (ui32DataWidth - 1);
116 HWREG(ui32Base + SSI_O_CR0) = ui32RegVal;
117 }
118
119 //*****************************************************************************
120 //
121 // Puts a data element into the SSI transmit FIFO
122 //
123 //*****************************************************************************
124 int32_t
SSIDataPutNonBlocking(uint32_t ui32Base,uint32_t ui32Data)125 SSIDataPutNonBlocking(uint32_t ui32Base, uint32_t ui32Data)
126 {
127 // Check the arguments.
128 ASSERT(SSIBaseValid(ui32Base));
129 ASSERT((ui32Data & (0xfffffffe << (HWREG(ui32Base + SSI_O_CR0) &
130 SSI_CR0_DSS_M))) == 0);
131
132 // Check for space to write.
133 if(HWREG(ui32Base + SSI_O_SR) & SSI_SR_TNF)
134 {
135 HWREG(ui32Base + SSI_O_DR) = ui32Data;
136 return(1);
137 }
138 else
139 {
140 return(0);
141 }
142 }
143
144 //*****************************************************************************
145 //
146 // Puts a data element into the SSI transmit FIFO
147 //
148 //*****************************************************************************
149 void
SSIDataPut(uint32_t ui32Base,uint32_t ui32Data)150 SSIDataPut(uint32_t ui32Base, uint32_t ui32Data)
151 {
152 // Check the arguments.
153 ASSERT(SSIBaseValid(ui32Base));
154 ASSERT((ui32Data & (0xfffffffe << (HWREG(ui32Base + SSI_O_CR0) &
155 SSI_CR0_DSS_M))) == 0);
156
157 // Wait until there is space.
158 while(!(HWREG(ui32Base + SSI_O_SR) & SSI_SR_TNF))
159 {
160 }
161
162 // Write the data to the SSI.
163 HWREG(ui32Base + SSI_O_DR) = ui32Data;
164 }
165
166 //*****************************************************************************
167 //
168 // Gets a data element from the SSI receive FIFO
169 //
170 //*****************************************************************************
171 void
SSIDataGet(uint32_t ui32Base,uint32_t * pui32Data)172 SSIDataGet(uint32_t ui32Base, uint32_t *pui32Data)
173 {
174 // Check the arguments.
175 ASSERT(SSIBaseValid(ui32Base));
176
177 // Wait until there is data to be read.
178 while(!(HWREG(ui32Base + SSI_O_SR) & SSI_SR_RNE))
179 {
180 }
181
182 // Read data from SSI.
183 *pui32Data = HWREG(ui32Base + SSI_O_DR);
184 }
185
186 //*****************************************************************************
187 //
188 // Gets a data element from the SSI receive FIFO
189 //
190 //*****************************************************************************
191 int32_t
SSIDataGetNonBlocking(uint32_t ui32Base,uint32_t * pui32Data)192 SSIDataGetNonBlocking(uint32_t ui32Base, uint32_t *pui32Data)
193 {
194 // Check the arguments.
195 ASSERT(SSIBaseValid(ui32Base));
196
197 // Check for data to read.
198 if(HWREG(ui32Base + SSI_O_SR) & SSI_SR_RNE)
199 {
200 *pui32Data = HWREG(ui32Base + SSI_O_DR);
201 return(1);
202 }
203 else
204 {
205 return(0);
206 }
207 }
208
209 //*****************************************************************************
210 //
211 // Registers an interrupt handler for the synchronous serial port
212 //
213 //*****************************************************************************
214 void
SSIIntRegister(uint32_t ui32Base,void (* pfnHandler)(void))215 SSIIntRegister(uint32_t ui32Base, void (*pfnHandler)(void))
216 {
217 uint32_t ui32Int;
218
219 // Check the arguments.
220 ASSERT(SSIBaseValid(ui32Base));
221
222 // Determine the interrupt number based on the SSI port.
223 ui32Int = (ui32Base == SSI0_BASE) ? INT_SSI0_COMB : INT_SSI1_COMB;
224
225 // Register the interrupt handler.
226 IntRegister(ui32Int, pfnHandler);
227
228 // Enable the synchronous serial port interrupt.
229 IntEnable(ui32Int);
230 }
231
232 //*****************************************************************************
233 //
234 // Unregisters an interrupt handler for the synchronous serial port
235 //
236 //*****************************************************************************
237 void
SSIIntUnregister(uint32_t ui32Base)238 SSIIntUnregister(uint32_t ui32Base)
239 {
240 uint32_t ui32Int;
241
242 // Check the arguments.
243 ASSERT(SSIBaseValid(ui32Base));
244
245 // Determine the interrupt number based on the SSI port.
246 ui32Int = (ui32Base == SSI0_BASE) ? INT_SSI0_COMB : INT_SSI1_COMB;
247
248 // Disable the interrupt.
249 IntDisable(ui32Int);
250
251 // Unregister the interrupt handler.
252 IntUnregister(ui32Int);
253 }
254
