i2c.h 6.2 KB

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  1. /*
  2. * (C) Copyright 2001
  3. * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
  4. *
  5. * See file CREDITS for list of people who contributed to this
  6. * project.
  7. *
  8. * This program is free software; you can redistribute it and/or
  9. * modify it under the terms of the GNU General Public License as
  10. * published by the Free Software Foundation; either version 2 of
  11. * the License, or (at your option) any later version.
  12. *
  13. * This program is distributed in the hope that it will be useful,
  14. * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15. * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  16. * GNU General Public License for more details.
  17. *
  18. * You should have received a copy of the GNU General Public License
  19. * along with this program; if not, write to the Free Software
  20. * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21. * MA 02111-1307 USA
  22. *
  23. * The original I2C interface was
  24. * (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
  25. * AIRVENT SAM s.p.a - RIMINI(ITALY)
  26. * but has been changed substantially.
  27. */
  28. #ifndef _I2C_H_
  29. #define _I2C_H_
  30. /*
  31. * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  32. *
  33. * The implementation MUST NOT use static or global variables if the
  34. * I2C routines are used to read SDRAM configuration information
  35. * because this is done before the memories are initialized. Limited
  36. * use of stack-based variables are OK (the initial stack size is
  37. * limited).
  38. *
  39. * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  40. */
  41. /*
  42. * Configuration items.
  43. */
  44. #define I2C_RXTX_LEN 128 /* maximum tx/rx buffer length */
  45. #if defined(CONFIG_I2C_MULTI_BUS)
  46. #if !defined(CONFIG_SYS_MAX_I2C_BUS)
  47. #define CONFIG_SYS_MAX_I2C_BUS 2
  48. #endif
  49. #define I2C_GET_BUS() i2c_get_bus_num()
  50. #define I2C_SET_BUS(a) i2c_set_bus_num(a)
  51. #else
  52. #define CONFIG_SYS_MAX_I2C_BUS 1
  53. #define I2C_GET_BUS() 0
  54. #define I2C_SET_BUS(a)
  55. #endif
  56. /* define the I2C bus number for RTC and DTT if not already done */
  57. #if !defined(CONFIG_SYS_RTC_BUS_NUM)
  58. #define CONFIG_SYS_RTC_BUS_NUM 0
  59. #endif
  60. #if !defined(CONFIG_SYS_DTT_BUS_NUM)
  61. #define CONFIG_SYS_DTT_BUS_NUM 0
  62. #endif
  63. #if !defined(CONFIG_SYS_SPD_BUS_NUM)
  64. #define CONFIG_SYS_SPD_BUS_NUM 0
  65. #endif
  66. #ifndef I2C_SOFT_DECLARATIONS
  67. # if defined(CONFIG_MPC8260)
  68. # define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
  69. # elif defined(CONFIG_8xx)
  70. # define I2C_SOFT_DECLARATIONS volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  71. # elif (defined(CONFIG_AT91RM9200) || \
  72. defined(CONFIG_AT91SAM9260) || defined(CONFIG_AT91SAM9261) || \
  73. defined(CONFIG_AT91SAM9263)) && !defined(CONFIG_AT91_LEGACY)
  74. # define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) AT91_PIO_BASE;
  75. # else
  76. # define I2C_SOFT_DECLARATIONS
  77. # endif
  78. #endif
  79. #ifdef CONFIG_8xx
  80. /* Set default value for the I2C bus speed on 8xx. In the
  81. * future, we'll define these in all 8xx board config files.
  82. */
  83. #ifndef CONFIG_SYS_I2C_SPEED
  84. #define CONFIG_SYS_I2C_SPEED 50000
  85. #endif
  86. #endif
  87. /*
  88. * Many boards/controllers/drivers don't support an I2C slave interface so
  89. * provide a default slave address for them for use in common code. A real
  90. * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
  91. * support a slave interface.
  92. */
  93. #ifndef CONFIG_SYS_I2C_SLAVE
  94. #define CONFIG_SYS_I2C_SLAVE 0xfe
  95. #endif
  96. /*
  97. * Initialization, must be called once on start up, may be called
  98. * repeatedly to change the speed and slave addresses.
  99. */
  100. void i2c_init(int speed, int slaveaddr);
  101. #ifdef CONFIG_SYS_I2C_INIT_BOARD
  102. void i2c_init_board(void);
  103. #endif
  104. #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
  105. void i2c_board_late_init(void);
  106. #endif
  107. #if defined(CONFIG_I2C_MUX)
  108. typedef struct _mux {
  109. uchar chip;
  110. uchar channel;
  111. char *name;
  112. struct _mux *next;
  113. } I2C_MUX;
  114. typedef struct _mux_device {
  115. int busid;
  116. I2C_MUX *mux; /* List of muxes, to reach the device */
  117. struct _mux_device *next;
  118. } I2C_MUX_DEVICE;
  119. I2C_MUX_DEVICE *i2c_mux_search_device(int id);
  120. I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf);
  121. int i2x_mux_select_mux(int bus);
  122. int i2c_mux_ident_muxstring_f (uchar *buf);
  123. #endif
  124. /*
  125. * Probe the given I2C chip address. Returns 0 if a chip responded,
  126. * not 0 on failure.
  127. */
  128. int i2c_probe(uchar chip);
  129. /*
  130. * Read/Write interface:
  131. * chip: I2C chip address, range 0..127
  132. * addr: Memory (register) address within the chip
  133. * alen: Number of bytes to use for addr (typically 1, 2 for larger
  134. * memories, 0 for register type devices with only one
  135. * register)
  136. * buffer: Where to read/write the data
  137. * len: How many bytes to read/write
  138. *
  139. * Returns: 0 on success, not 0 on failure
  140. */
  141. int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
  142. int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
  143. /*
  144. * Utility routines to read/write registers.
  145. */
  146. static inline u8 i2c_reg_read(u8 addr, u8 reg)
  147. {
  148. u8 buf;
  149. #ifdef CONFIG_8xx
  150. /* MPC8xx needs this. Maybe one day we can get rid of it. */
  151. i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
  152. #endif
  153. #ifdef DEBUG
  154. printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
  155. #endif
  156. i2c_read(addr, reg, 1, &buf, 1);
  157. return buf;
  158. }
  159. static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
  160. {
  161. #ifdef CONFIG_8xx
  162. /* MPC8xx needs this. Maybe one day we can get rid of it. */
  163. i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
  164. #endif
  165. #ifdef DEBUG
  166. printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
  167. __func__, addr, reg, val);
  168. #endif
  169. i2c_write(addr, reg, 1, &val, 1);
  170. }
  171. /*
  172. * Functions for setting the current I2C bus and its speed
  173. */
  174. /*
  175. * i2c_set_bus_num:
  176. *
  177. * Change the active I2C bus. Subsequent read/write calls will
  178. * go to this one.
  179. *
  180. * bus - bus index, zero based
  181. *
  182. * Returns: 0 on success, not 0 on failure
  183. *
  184. */
  185. int i2c_set_bus_num(unsigned int bus);
  186. /*
  187. * i2c_get_bus_num:
  188. *
  189. * Returns index of currently active I2C bus. Zero-based.
  190. */
  191. unsigned int i2c_get_bus_num(void);
  192. /*
  193. * i2c_set_bus_speed:
  194. *
  195. * Change the speed of the active I2C bus
  196. *
  197. * speed - bus speed in Hz
  198. *
  199. * Returns: 0 on success, not 0 on failure
  200. *
  201. */
  202. int i2c_set_bus_speed(unsigned int);
  203. /*
  204. * i2c_get_bus_speed:
  205. *
  206. * Returns speed of currently active I2C bus in Hz
  207. */
  208. unsigned int i2c_get_bus_speed(void);
  209. #endif /* _I2C_H_ */