altera_spi.c 4.5 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Altera SPI driver
  4. *
  5. * based on bfin_spi.c
  6. * Copyright (c) 2005-2008 Analog Devices Inc.
  7. * Copyright (C) 2010 Thomas Chou <thomas@wytron.com.tw>
  8. */
  9. #include <common.h>
  10. #include <dm.h>
  11. #include <errno.h>
  12. #include <malloc.h>
  13. #include <fdtdec.h>
  14. #include <spi.h>
  15. #include <asm/io.h>
  16. #define ALTERA_SPI_STATUS_RRDY_MSK BIT(7)
  17. #define ALTERA_SPI_CONTROL_SSO_MSK BIT(10)
  18. #ifndef CONFIG_ALTERA_SPI_IDLE_VAL
  19. #define CONFIG_ALTERA_SPI_IDLE_VAL 0xff
  20. #endif
  21. struct altera_spi_regs {
  22. u32 rxdata;
  23. u32 txdata;
  24. u32 status;
  25. u32 control;
  26. u32 _reserved;
  27. u32 slave_sel;
  28. };
  29. struct altera_spi_platdata {
  30. struct altera_spi_regs *regs;
  31. };
  32. struct altera_spi_priv {
  33. struct altera_spi_regs *regs;
  34. };
  35. static void spi_cs_activate(struct udevice *dev, uint cs)
  36. {
  37. struct udevice *bus = dev->parent;
  38. struct altera_spi_priv *priv = dev_get_priv(bus);
  39. struct altera_spi_regs *const regs = priv->regs;
  40. writel(1 << cs, &regs->slave_sel);
  41. writel(ALTERA_SPI_CONTROL_SSO_MSK, &regs->control);
  42. }
  43. static void spi_cs_deactivate(struct udevice *dev)
  44. {
  45. struct udevice *bus = dev->parent;
  46. struct altera_spi_priv *priv = dev_get_priv(bus);
  47. struct altera_spi_regs *const regs = priv->regs;
  48. writel(0, &regs->control);
  49. writel(0, &regs->slave_sel);
  50. }
  51. static int altera_spi_claim_bus(struct udevice *dev)
  52. {
  53. struct udevice *bus = dev->parent;
  54. struct altera_spi_priv *priv = dev_get_priv(bus);
  55. struct altera_spi_regs *const regs = priv->regs;
  56. writel(0, &regs->control);
  57. writel(0, &regs->slave_sel);
  58. return 0;
  59. }
  60. static int altera_spi_release_bus(struct udevice *dev)
  61. {
  62. struct udevice *bus = dev->parent;
  63. struct altera_spi_priv *priv = dev_get_priv(bus);
  64. struct altera_spi_regs *const regs = priv->regs;
  65. writel(0, &regs->slave_sel);
  66. return 0;
  67. }
  68. static int altera_spi_xfer(struct udevice *dev, unsigned int bitlen,
  69. const void *dout, void *din, unsigned long flags)
  70. {
  71. struct udevice *bus = dev->parent;
  72. struct altera_spi_priv *priv = dev_get_priv(bus);
  73. struct altera_spi_regs *const regs = priv->regs;
  74. struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
  75. /* assume spi core configured to do 8 bit transfers */
  76. unsigned int bytes = bitlen / 8;
  77. const unsigned char *txp = dout;
  78. unsigned char *rxp = din;
  79. uint32_t reg, data, start;
  80. debug("%s: bus:%i cs:%i bitlen:%i bytes:%i flags:%lx\n", __func__,
  81. bus->seq, slave_plat->cs, bitlen, bytes, flags);
  82. if (bitlen == 0)
  83. goto done;
  84. if (bitlen % 8) {
  85. flags |= SPI_XFER_END;
  86. goto done;
  87. }
  88. /* empty read buffer */
  89. if (readl(&regs->status) & ALTERA_SPI_STATUS_RRDY_MSK)
  90. readl(&regs->rxdata);
  91. if (flags & SPI_XFER_BEGIN)
  92. spi_cs_activate(dev, slave_plat->cs);
  93. while (bytes--) {
  94. if (txp)
  95. data = *txp++;
  96. else
  97. data = CONFIG_ALTERA_SPI_IDLE_VAL;
  98. debug("%s: tx:%x ", __func__, data);
  99. writel(data, &regs->txdata);
  100. start = get_timer(0);
  101. while (1) {
  102. reg = readl(&regs->status);
  103. if (reg & ALTERA_SPI_STATUS_RRDY_MSK)
  104. break;
  105. if (get_timer(start) > (CONFIG_SYS_HZ / 1000)) {
  106. debug("%s: Transmission timed out!\n", __func__);
  107. return -1;
  108. }
  109. }
  110. data = readl(&regs->rxdata);
  111. if (rxp)
  112. *rxp++ = data & 0xff;
  113. debug("rx:%x\n", data);
  114. }
  115. done:
  116. if (flags & SPI_XFER_END)
  117. spi_cs_deactivate(dev);
  118. return 0;
  119. }
  120. static int altera_spi_set_speed(struct udevice *bus, uint speed)
  121. {
  122. return 0;
  123. }
  124. static int altera_spi_set_mode(struct udevice *bus, uint mode)
  125. {
  126. return 0;
  127. }
  128. static int altera_spi_probe(struct udevice *bus)
  129. {
  130. struct altera_spi_platdata *plat = dev_get_platdata(bus);
  131. struct altera_spi_priv *priv = dev_get_priv(bus);
  132. priv->regs = plat->regs;
  133. return 0;
  134. }
  135. static int altera_spi_ofdata_to_platdata(struct udevice *bus)
  136. {
  137. struct altera_spi_platdata *plat = dev_get_platdata(bus);
  138. plat->regs = map_physmem(devfdt_get_addr(bus),
  139. sizeof(struct altera_spi_regs),
  140. MAP_NOCACHE);
  141. return 0;
  142. }
  143. static const struct dm_spi_ops altera_spi_ops = {
  144. .claim_bus = altera_spi_claim_bus,
  145. .release_bus = altera_spi_release_bus,
  146. .xfer = altera_spi_xfer,
  147. .set_speed = altera_spi_set_speed,
  148. .set_mode = altera_spi_set_mode,
  149. /*
  150. * cs_info is not needed, since we require all chip selects to be
  151. * in the device tree explicitly
  152. */
  153. };
  154. static const struct udevice_id altera_spi_ids[] = {
  155. { .compatible = "altr,spi-1.0" },
  156. {}
  157. };
  158. U_BOOT_DRIVER(altera_spi) = {
  159. .name = "altera_spi",
  160. .id = UCLASS_SPI,
  161. .of_match = altera_spi_ids,
  162. .ops = &altera_spi_ops,
  163. .ofdata_to_platdata = altera_spi_ofdata_to_platdata,
  164. .platdata_auto_alloc_size = sizeof(struct altera_spi_platdata),
  165. .priv_auto_alloc_size = sizeof(struct altera_spi_priv),
  166. .probe = altera_spi_probe,
  167. };