1 | /* |
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2 | * RTEMS driver for Blackfin UARTs |
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3 | * |
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4 | * COPYRIGHT (c) 2008 Kallisti Labs, Los Gatos, CA, USA |
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5 | * written by Allan Hessenflow <allanh@kallisti.com> |
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6 | * |
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7 | * The license and distribution terms for this file may be |
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8 | * found in the file LICENSE in this distribution or at |
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9 | * http://www.rtems.com/license/LICENSE. |
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10 | * |
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11 | * Modified: |
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12 | * $Author$ Added interrupt support and DMA support |
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13 | * |
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14 | * $Id$ |
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15 | */ |
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16 | |
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17 | |
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18 | #ifndef _UART_H_ |
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19 | #define _UART_H_ |
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20 | |
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21 | |
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22 | #ifdef __cplusplus |
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23 | extern "C" { |
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24 | #endif |
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25 | |
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26 | /** bfin_uart_channel object |
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27 | */ |
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28 | typedef struct { |
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29 | const char *name; /** Holds name of the device */ |
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30 | uint32_t uart_baseAddress; /** UART base address */ |
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31 | uint32_t uart_rxDmaBaseAddress; /** RX DMA base address */ |
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32 | uint32_t uart_txDmaBaseAddress; /** TX DMA base address */ |
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33 | bool uart_useInterrupts; /** are interrupts used */ |
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34 | bool uart_useDma; /** is dma used */ |
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35 | int uart_baud; /** baud rate, 0 for default */ |
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36 | |
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37 | void *termios; /** termios associated */ |
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38 | uint8_t volatile flags; /** flags for internal use */ |
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39 | uint16_t length; /** length for internal use */ |
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40 | } bfin_uart_channel_t; |
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41 | |
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42 | |
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43 | typedef struct { |
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44 | uint32_t freq; |
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45 | int num_channels; |
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46 | bfin_uart_channel_t *channels; |
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47 | } bfin_uart_config_t; |
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48 | |
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49 | /** |
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50 | * @param base_address defines the UART base address |
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51 | * @param source defines the source that caused the interrupt. This argument |
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52 | * will help us in identifying if Rx or TX caused the interrupt. |
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53 | */ |
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54 | typedef struct { |
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55 | uint32_t base_address; |
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56 | int source; |
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57 | } bfin_uart_arg_t; |
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58 | |
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59 | |
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60 | |
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61 | char bfin_uart_poll_read(rtems_device_minor_number minor); |
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62 | |
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63 | void bfin_uart_poll_write(int minor, char c); |
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64 | |
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65 | |
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66 | /** |
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67 | * Uart initialization function. |
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68 | * @param major major number of the device |
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69 | * @param config configuration parameters |
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70 | * @return rtems status code |
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71 | */ |
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72 | rtems_status_code bfin_uart_initialize(rtems_device_major_number major, |
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73 | bfin_uart_config_t *config); |
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74 | |
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75 | |
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76 | |
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77 | /** |
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78 | * Opens the device in different modes. The supported modes are |
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79 | * 1. Polling |
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80 | * 2. Interrupt |
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81 | * 3. DMA |
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82 | * At exit the uart_Exit function will be called to flush the device. |
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83 | * |
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84 | * @param major Major number of the device |
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85 | * @param minor Minor number of the device |
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86 | * @param arg |
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87 | * @return |
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88 | */ |
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89 | rtems_device_driver bfin_uart_open(rtems_device_major_number major, |
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90 | rtems_device_minor_number minor, void *arg); |
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91 | |
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92 | |
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93 | |
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94 | /** |
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95 | * This function implements TX dma ISR. It clears the IRQ and dequeues a char |
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96 | * The channel argument will have the base address. Since there are two uart |
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97 | * and both the uarts can use the same tx dma isr. |
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98 | * |
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99 | * TODO: 1. Error checking 2. sending correct length ie after looking at the |
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100 | * number of elements the uart transmitted. |
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101 | * |
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102 | * @param _arg argument passed to the interrupt handler. It contains the |
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103 | * channel argument. |
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104 | */ |
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105 | void bfinUart_txDmaIsr(void *_arg); |
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106 | |
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107 | |
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108 | |
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109 | /** |
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110 | * RX DMA ISR. |
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111 | * The polling route is used for receiving the characters. This is a place |
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112 | * holder for future implementation. |
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113 | * @param _arg |
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114 | */ |
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115 | void bfinUart_rxDmaIsr(void *_arg); |
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116 | |
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117 | |
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118 | /** |
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119 | * This function implements TX ISR. The function gets called when the TX FIFO is |
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120 | * empty. It clears the interrupt and dequeues the character. It only tx one |
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121 | * character at a time. |
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122 | * |
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123 | * TODO: error handling. |
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124 | * @param _arg gets the channel information. |
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125 | */ |
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126 | void bfinUart_txIsr(void *_arg); |
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127 | |
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128 | |
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129 | /** |
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130 | * This function implements RX ISR |
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131 | */ |
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132 | void bfinUart_rxIsr(void *_arg); |
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133 | |
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134 | |
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135 | #ifdef __cplusplus |
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136 | } |
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137 | #endif |
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138 | |
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139 | #endif /* _UART_H_ */ |
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140 | |
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