1 | /* |
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2 | * Copyright (c) 2017 embedded brains GmbH. All rights reserved. |
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3 | * |
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4 | * embedded brains GmbH |
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5 | * Dornierstr. 4 |
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6 | * 82178 Puchheim |
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7 | * Germany |
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8 | * <info@embedded-brains.de> |
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9 | * |
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10 | * The license and distribution terms for this file may be |
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11 | * found in the file LICENSE in this distribution or at |
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12 | * http://www.rtems.org/license/LICENSE. |
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13 | */ |
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14 | |
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15 | #include <bsp.h> |
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16 | #include <bsp/fdt.h> |
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17 | #include <libfdt.h> |
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18 | #include <arm/freescale/imx/imx_ccmvar.h> |
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19 | #include <arm/freescale/imx/imx_ecspireg.h> |
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20 | #include <dev/spi/spi.h> |
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21 | #include <rtems/irq-extension.h> |
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22 | #include <sys/param.h> |
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23 | #include <sys/endian.h> |
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24 | |
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25 | #define IMX_ECSPI_FIFO_SIZE 64 |
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26 | |
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27 | typedef struct imx_ecspi_bus imx_ecspi_bus; |
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28 | |
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29 | struct imx_ecspi_bus { |
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30 | spi_bus base; |
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31 | volatile imx_ecspi *regs; |
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32 | uint32_t conreg; |
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33 | uint32_t speed_hz; |
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34 | uint32_t mode; |
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35 | uint8_t bits_per_word; |
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36 | uint8_t cs; |
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37 | uint32_t msg_todo; |
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38 | const spi_ioc_transfer *msg; |
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39 | uint32_t todo; |
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40 | uint32_t in_transfer; |
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41 | uint8_t *rx_buf; |
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42 | const uint8_t *tx_buf; |
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43 | void (*push)(imx_ecspi_bus *, volatile imx_ecspi *); |
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44 | void (*pop)(imx_ecspi_bus *, volatile imx_ecspi *); |
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45 | rtems_id task_id; |
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46 | rtems_vector_number irq; |
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47 | }; |
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48 | |
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49 | static bool imx_ecspi_is_rx_fifo_not_empty(volatile imx_ecspi *regs) |
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50 | { |
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51 | return (regs->statreg & IMX_ECSPI_RR) != 0; |
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52 | } |
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53 | |
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54 | static void imx_ecspi_reset(volatile imx_ecspi *regs) |
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55 | { |
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56 | while (imx_ecspi_is_rx_fifo_not_empty(regs)) { |
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57 | regs->rxdata; |
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58 | } |
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59 | } |
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60 | |
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61 | static void imx_ecspi_done(imx_ecspi_bus *bus) |
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62 | { |
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63 | rtems_event_transient_send(bus->task_id); |
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64 | } |
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65 | |
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66 | #define IMC_ECSPI_PUSH(type) \ |
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67 | static void imx_ecspi_push_##type(imx_ecspi_bus *bus, volatile imx_ecspi *regs) \ |
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68 | { \ |
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69 | type val = 0; \ |
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70 | if (bus->tx_buf != NULL) { \ |
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71 | val = *(type *)bus->tx_buf; \ |
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72 | bus->tx_buf += sizeof(type); \ |
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73 | } \ |
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74 | bus->todo -= sizeof(type); \ |
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75 | regs->txdata = val; \ |
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76 | } |
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77 | |
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78 | #define IMX_ECSPI_POP(type) \ |
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79 | static void imx_ecspi_pop_##type(imx_ecspi_bus *bus, volatile imx_ecspi *regs) \ |
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80 | { \ |
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81 | uint32_t val = regs->rxdata; \ |
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82 | if (bus->rx_buf != NULL) { \ |
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83 | *(type *)bus->rx_buf = val; \ |
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84 | bus->rx_buf += sizeof(type); \ |
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85 | } \ |
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86 | } |
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87 | |
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88 | IMC_ECSPI_PUSH(uint8_t) |
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89 | IMX_ECSPI_POP(uint8_t) |
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90 | IMC_ECSPI_PUSH(uint16_t) |
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91 | IMX_ECSPI_POP(uint16_t) |
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92 | IMC_ECSPI_PUSH(uint32_t) |
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93 | IMX_ECSPI_POP(uint32_t) |
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94 | |
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95 | static void imx_ecspi_push_uint32_t_swap( |
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96 | imx_ecspi_bus *bus, |
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97 | volatile imx_ecspi *regs |
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98 | ) |
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99 | { |
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100 | uint32_t val = 0; |
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101 | |
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102 | if (bus->tx_buf != NULL) { |
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103 | val = bswap32(*(uint32_t *)bus->tx_buf); |
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104 | bus->tx_buf += sizeof(uint32_t); |
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105 | } |
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106 | |
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107 | bus->todo -= sizeof(uint32_t); |
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108 | regs->txdata = val; |
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109 | } |
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110 | |
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111 | static void imx_ecspi_pop_uint32_t_swap( |
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112 | imx_ecspi_bus *bus, |
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113 | volatile imx_ecspi *regs |
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114 | ) |
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115 | { |
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116 | uint32_t val = regs->rxdata; |
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117 | |
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118 | if (bus->rx_buf != NULL) { |
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119 | *(uint32_t *)bus->rx_buf = bswap32(val); |
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120 | bus->rx_buf += sizeof(uint32_t); |
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121 | } |
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122 | } |
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123 | |
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124 | static void imx_ecspi_push(imx_ecspi_bus *bus, volatile imx_ecspi *regs) |
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125 | { |
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126 | while (bus->todo > 0 && bus->in_transfer < IMX_ECSPI_FIFO_SIZE) { |
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127 | (*bus->push)(bus, regs); |
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128 | ++bus->in_transfer; |
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129 | } |
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130 | } |
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131 | |
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132 | static uint32_t imx_ecspi_conreg_divider(imx_ecspi_bus *bus, uint32_t speed_hz) |
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133 | { |
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134 | uint32_t post; |
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135 | uint32_t pre; |
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136 | uint32_t clk_in; |
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137 | |
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138 | clk_in = bus->base.max_speed_hz; |
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139 | |
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140 | if (clk_in > speed_hz) { |
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141 | post = fls((int) clk_in) - fls((int) speed_hz); |
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142 | |
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143 | if (clk_in > (speed_hz << post)) { |
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144 | ++post; |
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145 | } |
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146 | |
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147 | /* We have 2^4 == 16, use the pre-divider for this factor */ |
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148 | post = MAX(4, post) - 4; |
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149 | |
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150 | if (post <= 0xf) { |
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151 | pre = howmany(clk_in, speed_hz << post) - 1; |
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152 | } else { |
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153 | post = 0xf; |
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154 | pre = 0xf; |
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155 | } |
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156 | } else { |
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157 | post = 0; |
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158 | pre = 0; |
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159 | } |
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160 | |
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161 | return IMX_ECSPI_CONREG_POST_DIVIDER(post) |
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162 | | IMX_ECSPI_CONREG_PRE_DIVIDER(pre); |
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163 | } |
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164 | |
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165 | static void imx_ecspi_config( |
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166 | imx_ecspi_bus *bus, |
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167 | volatile imx_ecspi *regs, |
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168 | uint32_t speed_hz, |
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169 | uint8_t bits_per_word, |
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170 | uint32_t mode, |
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171 | uint8_t cs |
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172 | ) |
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173 | { |
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174 | uint32_t conreg; |
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175 | uint32_t testreg; |
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176 | uint32_t configreg; |
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177 | uint32_t cs_bit; |
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178 | |
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179 | conreg = IMX_ECSPI_CONREG_CHANNEL_MODE(0xf) |
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180 | | IMX_ECSPI_CONREG_SMC | IMX_ECSPI_CONREG_EN; |
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181 | testreg = regs->testreg; |
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182 | configreg = regs->configreg; |
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183 | cs_bit = 1U << cs; |
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184 | |
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185 | conreg |= imx_ecspi_conreg_divider(bus, speed_hz); |
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186 | conreg |= IMX_ECSPI_CONREG_CHANNEL_SELECT(cs); |
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187 | |
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188 | configreg |= IMX_ECSPI_CONFIGREG_SS_CTL(cs_bit); |
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189 | |
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190 | if ((mode & SPI_CPHA) != 0) { |
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191 | configreg |= IMX_ECSPI_CONFIGREG_SCLK_PHA(cs_bit); |
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192 | } else { |
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193 | configreg &= ~IMX_ECSPI_CONFIGREG_SCLK_PHA(cs_bit); |
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194 | } |
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195 | |
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196 | if ((mode & SPI_CPOL) != 0) { |
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197 | configreg |= IMX_ECSPI_CONFIGREG_SCLK_POL(cs_bit); |
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198 | configreg |= IMX_ECSPI_CONFIGREG_SCLK_CTL(cs_bit); |
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199 | } else { |
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200 | configreg &= ~IMX_ECSPI_CONFIGREG_SCLK_POL(cs_bit); |
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201 | configreg &= ~IMX_ECSPI_CONFIGREG_SCLK_CTL(cs_bit); |
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202 | } |
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203 | |
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204 | if ((mode & SPI_CS_HIGH) != 0) { |
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205 | configreg |= IMX_ECSPI_CONFIGREG_SS_POL(cs_bit); |
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206 | } else { |
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207 | configreg &= ~IMX_ECSPI_CONFIGREG_SS_POL(cs_bit); |
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208 | } |
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209 | |
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210 | if ((mode & SPI_LOOP) != 0) { |
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211 | testreg |= IMX_ECSPI_TESTREG_LBC; |
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212 | } else { |
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213 | testreg &= ~IMX_ECSPI_TESTREG_LBC; |
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214 | } |
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215 | |
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216 | regs->conreg = conreg; |
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217 | regs->testreg = testreg; |
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218 | regs->configreg = configreg; |
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219 | |
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220 | bus->conreg = conreg; |
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221 | bus->speed_hz = speed_hz; |
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222 | bus->bits_per_word = bits_per_word; |
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223 | bus->mode = mode; |
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224 | bus->cs = cs; |
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225 | |
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226 | /* FIXME: Clock change delay */ |
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227 | } |
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228 | |
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229 | static void imx_ecspi_set_push_pop( |
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230 | imx_ecspi_bus *bus, |
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231 | uint32_t len, |
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232 | uint8_t bits_per_word |
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233 | ) |
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234 | { |
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235 | uint32_t conreg; |
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236 | |
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237 | conreg = bus->conreg; |
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238 | |
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239 | if (len % 4 == 0 && len <= IMX_ECSPI_FIFO_SIZE) { |
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240 | conreg |= IMX_ECSPI_CONREG_BURST_LENGTH((len * 8) - 1); |
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241 | |
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242 | bus->push = imx_ecspi_push_uint32_t_swap; |
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243 | bus->pop = imx_ecspi_pop_uint32_t_swap; |
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244 | } else { |
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245 | conreg |= IMX_ECSPI_CONREG_BURST_LENGTH(bits_per_word - 1); |
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246 | |
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247 | if (bits_per_word <= 8) { |
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248 | bus->push = imx_ecspi_push_uint8_t; |
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249 | bus->pop = imx_ecspi_pop_uint8_t; |
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250 | } else if (bits_per_word <= 16) { |
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251 | bus->push = imx_ecspi_push_uint16_t; |
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252 | bus->pop = imx_ecspi_pop_uint16_t; |
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253 | } else { |
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254 | bus->push = imx_ecspi_push_uint32_t; |
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255 | bus->pop = imx_ecspi_pop_uint32_t; |
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256 | } |
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257 | } |
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258 | |
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259 | bus->regs->conreg = conreg; |
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260 | } |
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261 | |
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262 | static void imx_ecspi_next_msg(imx_ecspi_bus *bus, volatile imx_ecspi *regs) |
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263 | { |
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264 | if (bus->msg_todo > 0) { |
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265 | const spi_ioc_transfer *msg; |
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266 | |
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267 | msg = bus->msg; |
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268 | |
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269 | if ( |
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270 | msg->speed_hz != bus->speed_hz |
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271 | || msg->bits_per_word != bus->bits_per_word |
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272 | || msg->mode != bus->mode |
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273 | || msg->cs != bus->cs |
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274 | ) { |
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275 | imx_ecspi_config( |
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276 | bus, |
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277 | regs, |
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278 | msg->speed_hz, |
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279 | msg->bits_per_word, |
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280 | msg->mode, |
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281 | msg->cs |
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282 | ); |
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283 | } |
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284 | |
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285 | bus->todo = msg->len; |
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286 | bus->rx_buf = msg->rx_buf; |
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287 | bus->tx_buf = msg->tx_buf; |
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288 | imx_ecspi_set_push_pop(bus, msg->len, msg->bits_per_word); |
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289 | imx_ecspi_push(bus, regs); |
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290 | regs->intreg = IMX_ECSPI_TE; |
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291 | } else { |
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292 | regs->intreg = 0; |
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293 | imx_ecspi_done(bus); |
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294 | } |
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295 | } |
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296 | |
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297 | static void imx_ecspi_interrupt(void *arg) |
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298 | { |
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299 | imx_ecspi_bus *bus; |
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300 | volatile imx_ecspi *regs; |
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301 | |
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302 | bus = arg; |
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303 | regs = bus->regs; |
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304 | |
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305 | while (imx_ecspi_is_rx_fifo_not_empty(regs)) { |
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306 | (*bus->pop)(bus, regs); |
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307 | --bus->in_transfer; |
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308 | } |
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309 | |
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310 | if (bus->todo > 0) { |
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311 | imx_ecspi_push(bus, regs); |
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312 | } else if (bus->in_transfer > 0) { |
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313 | regs->intreg = IMX_ECSPI_RR; |
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314 | } else { |
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315 | --bus->msg_todo; |
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316 | ++bus->msg; |
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317 | imx_ecspi_next_msg(bus, regs); |
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318 | } |
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319 | } |
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320 | |
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321 | static int imx_ecspi_transfer( |
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322 | spi_bus *base, |
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323 | const spi_ioc_transfer *msgs, |
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324 | uint32_t n |
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325 | ) |
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326 | { |
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327 | imx_ecspi_bus *bus; |
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328 | |
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329 | bus = (imx_ecspi_bus *) base; |
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330 | |
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331 | bus->msg_todo = n; |
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332 | bus->msg = &msgs[0]; |
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333 | bus->task_id = rtems_task_self(); |
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334 | |
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335 | imx_ecspi_next_msg(bus, bus->regs); |
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336 | rtems_event_transient_receive(RTEMS_WAIT, RTEMS_NO_TIMEOUT); |
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337 | return 0; |
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338 | } |
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339 | |
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340 | static void imx_ecspi_destroy(spi_bus *base) |
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341 | { |
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342 | imx_ecspi_bus *bus; |
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343 | |
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344 | bus = (imx_ecspi_bus *) base; |
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345 | rtems_interrupt_handler_remove(bus->irq, imx_ecspi_interrupt, bus); |
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346 | spi_bus_destroy_and_free(&bus->base); |
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347 | } |
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348 | |
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349 | static int imx_ecspi_init(imx_ecspi_bus *bus, const void *fdt, int node) |
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350 | { |
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351 | rtems_status_code sc; |
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352 | int len; |
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353 | const uint32_t *val; |
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354 | |
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355 | imx_ecspi_config( |
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356 | bus, |
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357 | bus->regs, |
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358 | bus->base.max_speed_hz, |
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359 | 8, |
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360 | 0, |
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361 | 0 |
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362 | ); |
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363 | imx_ecspi_reset(bus->regs); |
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364 | |
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365 | sc = rtems_interrupt_handler_install( |
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366 | bus->irq, |
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367 | "ECSPI", |
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368 | RTEMS_INTERRUPT_UNIQUE, |
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369 | imx_ecspi_interrupt, |
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370 | bus |
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371 | ); |
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372 | if (sc != RTEMS_SUCCESSFUL) { |
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373 | return EAGAIN; |
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374 | } |
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375 | |
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376 | val = fdt_getprop(fdt, node, "pinctrl-0", &len); |
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377 | if (len == 4) { |
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378 | imx_iomux_configure_pins(fdt, fdt32_to_cpu(val[0])); |
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379 | } |
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380 | |
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381 | return 0; |
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382 | } |
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383 | |
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384 | static int imx_ecspi_setup(spi_bus *base) |
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385 | { |
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386 | imx_ecspi_bus *bus; |
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387 | |
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388 | bus = (imx_ecspi_bus *) base; |
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389 | |
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390 | if ( |
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391 | bus->base.speed_hz > imx_ccm_ipg_hz() |
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392 | || bus->base.bits_per_word > 32 |
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393 | ) { |
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394 | return -EINVAL; |
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395 | } |
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396 | |
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397 | imx_ecspi_config( |
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398 | bus, |
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399 | bus->regs, |
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400 | bus->base.speed_hz, |
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401 | bus->base.bits_per_word, |
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402 | bus->base.mode, |
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403 | bus->base.cs |
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404 | ); |
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405 | return 0; |
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406 | } |
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407 | |
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408 | int spi_bus_register_imx(const char *bus_path, const char *alias_or_path) |
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409 | { |
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410 | const void *fdt; |
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411 | const char *path; |
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412 | int node; |
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413 | imx_ecspi_bus *bus; |
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414 | int eno; |
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415 | |
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416 | fdt = bsp_fdt_get(); |
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417 | path = fdt_get_alias(fdt, alias_or_path); |
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418 | |
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419 | if (path == NULL) { |
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420 | path = alias_or_path; |
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421 | } |
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422 | |
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423 | node = fdt_path_offset(fdt, path); |
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424 | if (node < 0) { |
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425 | rtems_set_errno_and_return_minus_one(ENXIO); |
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426 | } |
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427 | |
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428 | bus = (imx_ecspi_bus *) spi_bus_alloc_and_init(sizeof(*bus)); |
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429 | if (bus == NULL){ |
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430 | return -1; |
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431 | } |
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432 | |
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433 | bus->base.max_speed_hz = imx_ccm_ipg_hz(); |
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434 | bus->base.delay_usecs = 1; |
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435 | bus->regs = imx_get_reg_of_node(fdt, node); |
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436 | bus->irq = imx_get_irq_of_node(fdt, node, 0); |
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437 | |
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438 | eno = imx_ecspi_init(bus, fdt, node); |
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439 | if (eno != 0) { |
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440 | (*bus->base.destroy)(&bus->base); |
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441 | rtems_set_errno_and_return_minus_one(eno); |
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442 | } |
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443 | |
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444 | bus->base.transfer = imx_ecspi_transfer; |
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445 | bus->base.destroy = imx_ecspi_destroy; |
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446 | bus->base.setup = imx_ecspi_setup; |
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447 | |
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448 | return spi_bus_register(&bus->base, bus_path); |
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449 | } |
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