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i2s_18xx_43xx.c
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1 /*
2 * @brief LPC18xx/43xx I2S driver
3 *
4 * @note
5 * Copyright(C) NXP Semiconductors, 2012
6 * All rights reserved.
7 *
8 * @par
9 * Software that is described herein is for illustrative purposes only
10 * which provides customers with programming information regarding the
11 * LPC products. This software is supplied "AS IS" without any warranties of
12 * any kind, and NXP Semiconductors and its licensor disclaim any and
13 * all warranties, express or implied, including all implied warranties of
14 * merchantability, fitness for a particular purpose and non-infringement of
15 * intellectual property rights. NXP Semiconductors assumes no responsibility
16 * or liability for the use of the software, conveys no license or rights under any
17 * patent, copyright, mask work right, or any other intellectual property rights in
18 * or to any products. NXP Semiconductors reserves the right to make changes
19 * in the software without notification. NXP Semiconductors also makes no
20 * representation or warranty that such application will be suitable for the
21 * specified use without further testing or modification.
22 *
23 * @par
24 * Permission to use, copy, modify, and distribute this software and its
25 * documentation is hereby granted, under NXP Semiconductors' and its
26 * licensor's relevant copyrights in the software, without fee, provided that it
27 * is used in conjunction with NXP Semiconductors microcontrollers. This
28 * copyright, permission, and disclaimer notice must appear in all copies of
29 * this code.
30 */
31
32 #include "chip.h"
33
34 /*****************************************************************************
35 * Private types/enumerations/variables
36 ****************************************************************************/
37
38 static uint8_t clksEnabled;
39
40 /*****************************************************************************
41 * Public types/enumerations/variables
42 ****************************************************************************/
43
44 /*****************************************************************************
45 * Private functions
46 ****************************************************************************/
47
48 /*****************************************************************************
49 * Public functions
50 ****************************************************************************/
51
52 /* Initialize the I2S interface */
53 void Chip_I2S_Init(LPC_I2S_T *pI2S)
54 {
55 if (clksEnabled == 0) {
56 Chip_Clock_Enable(CLK_APB1_I2S);
57 }
58 clksEnabled++;
59
60 IP_I2S_Init(pI2S);
61 }
62
63 /* Shutdown I2S */
64 void Chip_I2S_DeInit(LPC_I2S_T *pI2S)
65 {
66 IP_I2S_DeInit(pI2S);
67
68 clksEnabled--;
69 if (clksEnabled == 0) {
70 Chip_Clock_Disable(CLK_APB1_I2S);
71 }
72 }
73
74 /* Configure I2S for Audio Format input */
75 Status Chip_I2S_Config(LPC_I2S_T *pI2S, uint8_t TRMode, Chip_I2S_Audio_Format_T *audio_format)
76 {
77 uint32_t pClk;
78 uint32_t x, y;
79 uint64_t divider;
80 uint16_t dif;
81 uint16_t x_divide = 0, y_divide = 0;
82 uint32_t N;
83 uint16_t err, ErrorOptimal = 0xFFFF;
84
85 pClk = (uint64_t) Chip_Clock_GetRate(CLK_APB1_I2S);
86
87 /* divider is a fixed point number with 16 fractional bits */
88 divider = (((uint64_t) (audio_format->SampleRate) * 2 * (audio_format->WordWidth) * 2) << 16) / pClk;
89 /* find N that make x/y <= 1 -> divider <= 2^16 */
90 for (N = 64; N > 0; N--) {
91 if ((divider * N) < (1 << 16)) {
92 break;
93 }
94 }
95 if (N == 0) {
96 return ERROR;
97 }
98 divider *= N;
99 for (y = 255; y > 0; y--) {
100 x = y * divider;
101 if (x & (0xFF000000)) {
102 continue;
103 }
104 dif = x & 0xFFFF;
105 if (dif > 0x8000) {
106 err = 0x10000 - dif;
107 }
108 else {
109 err = dif;
110 }
111 if (err == 0) {
112 y_divide = y;
113 break;
114 }
115 else if (err < ErrorOptimal) {
116 ErrorOptimal = err;
117 y_divide = y;
118 }
119 }
120 x_divide = ((uint64_t) y_divide * (audio_format->SampleRate) * 2 * (audio_format->WordWidth) * N * 2) / pClk;
121 if (x_divide >= 256) {
122 x_divide = 0xFF;
123 }
124 if (x_divide == 0) {
125 x_divide = 1;
126 }
127 if (audio_format->WordWidth <= 8) {
128 IP_I2S_SetWordWidth(pI2S, TRMode, I2S_WORDWIDTH_8);
129 }
130 else if (audio_format->WordWidth <= 16) {
131 IP_I2S_SetWordWidth(pI2S, TRMode, I2S_WORDWIDTH_16);
132 }
133 else {
134 IP_I2S_SetWordWidth(pI2S, TRMode, I2S_WORDWIDTH_32);
135 }
136 IP_I2S_SetMono(pI2S, TRMode, (audio_format->ChannelNumber) == 1 ? I2S_MONO : I2S_STEREO);
137 IP_I2S_SetMasterSlaveMode(pI2S, TRMode, I2S_MASTER_MODE);
138 IP_I2S_SetWS_Halfperiod(pI2S, TRMode, audio_format->WordWidth - 1);
139 IP_I2S_ModeConfig(pI2S, TRMode, I2S_TXMODE_CLKSEL(0), !I2S_TXMODE_4PIN_ENABLE, !I2S_TXMODE_MCENA);
140 IP_I2S_SetBitRate(pI2S, TRMode, N - 1);
141 IP_I2S_SetXYDivider(pI2S, TRMode, x_divide, y_divide);
142 return SUCCESS;
143 }
144
145 /* Enable/Disable Interrupt with a specific FIFO depth */
146 void Chip_I2S_Int_Cmd(LPC_I2S_T *pI2S, uint8_t TRMode, FunctionalState NewState, uint8_t FIFO_Depth)
147 {
148 IP_I2S_InterruptCmd(pI2S, TRMode, NewState);
149 IP_I2S_SetFIFODepthIRQ(pI2S, TRMode, FIFO_Depth);
150 }
151
152 /* Enable/Disable DMA with a specific FIFO depth */
153 void Chip_I2S_DMA_Cmd(LPC_I2S_T *pI2S,
154 uint8_t TRMode,
155 uint8_t DMANum,
156 FunctionalState NewState,
157 uint8_t FIFO_Depth)
158 {
159 IP_I2S_SetFIFODepthDMA(pI2S, TRMode, (IP_I2S_DMARequestNumber_T) DMANum, FIFO_Depth);
160 IP_I2S_DMACmd(pI2S, (IP_I2S_DMARequestNumber_T) DMANum, TRMode, NewState);
161 }