1 /******************************************************************************
2 * Filename: i2c.c
3 *
4 * Description: Driver for I2C.
5 *
6 * Copyright (c) 2022 Texas Instruments Incorporated
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions are met:
10 *
11 * 1) Redistributions of source code must retain the above copyright notice,
12 * this list of conditions and the following disclaimer.
13 *
14 * 2) Redistributions in binary form must reproduce the above copyright notice,
15 * this list of conditions and the following disclaimer in the documentation
16 * and/or other materials provided with the distribution.
17 *
18 * 3) Neither the name of the copyright holder nor the names of its
19 * contributors may be used to endorse or promote products derived from this
20 * software without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
23 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
26 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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31 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
33 *
34 ******************************************************************************/
35
36 #include "i2c.h"
37
38 //*****************************************************************************
39 //
40 // Initializes the I2C Controller module
41 //
42 //*****************************************************************************
I2CControllerInitExpClk(uint32_t base,bool fast)43 void I2CControllerInitExpClk(uint32_t base, bool fast)
44 {
45 uint32_t sclFreq;
46 uint32_t tpr;
47
48 // Check the arguments.
49 ASSERT(I2CBaseValid(base));
50
51 // Must enable the device before doing anything else.
52 I2CControllerEnable(base);
53
54 // Get the desired SCL speed.
55 if (fast == true)
56 {
57 sclFreq = 400000;
58 }
59 else
60 {
61 sclFreq = 100000;
62 }
63
64 // Compute the clock divider that achieves the fastest speed less than or
65 // equal to the desired speed. The numerator is biased to favor a larger
66 // clock divider so that the resulting clock is always less than or equal
67 // to the desired clock, never greater.
68 tpr = ((I2C_CLK_FREQ + (2 * 10 * sclFreq) - 1) / (2 * 10 * sclFreq)) - 1;
69 HWREG(base + I2C_O_CTPR) = tpr;
70 }
71
72 //*****************************************************************************
73 //
74 // Gets the error status of the I2C Controller module
75 //
76 //*****************************************************************************
I2CControllerError(uint32_t base)77 uint32_t I2CControllerError(uint32_t base)
78 {
79 uint32_t err;
80
81 // Check the arguments.
82 ASSERT(I2CBaseValid(base));
83
84 // Get the raw error state.
85 err = HWREG(base + I2C_O_CSTA);
86
87 // If the I2C controller is busy, then all the other status bits are invalid,
88 // and there is no error to report.
89 if (err & I2C_CSTA_BUSY_M)
90 {
91 return (I2C_CONTROLLER_ERR_NONE);
92 }
93
94 // Check for errors.
95 if (err & (I2C_CSTA_ERR_M | I2C_CSTA_ARBLST_M))
96 {
97 return (err & (I2C_CSTA_ARBLST_M | I2C_CSTA_DATACKN_M | I2C_CSTA_ADRACKN_M));
98 }
99 else
100 {
101 return (I2C_CONTROLLER_ERR_NONE);
102 }
103 }
104
