include/i2c.h

   1 /*
   2  * (C) Copyright 2001
   3  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  *
   7  * The original I2C interface was
   8  *   (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
   9  *   AIRVENT SAM s.p.a - RIMINI(ITALY)
  10  * but has been changed substantially.
  11  */
  12
  13 #ifndef _I2C_H_
  14 #define _I2C_H_
  15
  16 /*
  17  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  18  *
  19  * The implementation MUST NOT use static or global variables if the
  20  * I2C routines are used to read SDRAM configuration information
  21  * because this is done before the memories are initialized. Limited
  22  * use of stack-based variables are OK (the initial stack size is
  23  * limited).
  24  *
  25  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  26  */
  27
  28 /*
  29  * Configuration items.
  30  */
  31 #define I2C_RXTX_LEN    128     /* maximum tx/rx buffer length */
  32
  33 #ifdef  CONFIG_I2C_MULTI_BUS
  34 #define MAX_I2C_BUS                     2
  35 #define I2C_MULTI_BUS                   1
  36 #else
  37 #define MAX_I2C_BUS                     1
  38 #define I2C_MULTI_BUS                   0
  39 #endif
  40
  41 #if !defined(CONFIG_SYS_MAX_I2C_BUS)
  42 #define CONFIG_SYS_MAX_I2C_BUS          MAX_I2C_BUS
  43 #endif
  44
  45 /* define the I2C bus number for RTC and DTT if not already done */
  46 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
  47 #define CONFIG_SYS_RTC_BUS_NUM          0
  48 #endif
  49 #if !defined(CONFIG_SYS_DTT_BUS_NUM)
  50 #define CONFIG_SYS_DTT_BUS_NUM          0
  51 #endif
  52 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
  53 #define CONFIG_SYS_SPD_BUS_NUM          0
  54 #endif
  55
  56 #ifndef I2C_SOFT_DECLARATIONS
  57 # if defined(CONFIG_MPC8260)
  58 #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
  59 # elif defined(CONFIG_8xx)
  60 #  define I2C_SOFT_DECLARATIONS volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  61
  62 # elif (defined(CONFIG_AT91RM9200) || \
  63         defined(CONFIG_AT91SAM9260) ||  defined(CONFIG_AT91SAM9261) || \
  64         defined(CONFIG_AT91SAM9263)) && !defined(CONFIG_AT91_LEGACY)
  65 #  define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) ATMEL_BASE_PIOA;
  66 # else
  67 #  define I2C_SOFT_DECLARATIONS
  68 # endif
  69 #endif
  70
  71 #ifdef CONFIG_8xx
  72 /* Set default value for the I2C bus speed on 8xx. In the
  73  * future, we'll define these in all 8xx board config files.
  74  */
  75 #ifndef CONFIG_SYS_I2C_SPEED
  76 #define CONFIG_SYS_I2C_SPEED    50000
  77 #endif
  78 #endif
  79
  80 /*
  81  * Many boards/controllers/drivers don't support an I2C slave interface so
  82  * provide a default slave address for them for use in common code.  A real
  83  * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
  84  * support a slave interface.
  85  */
  86 #ifndef CONFIG_SYS_I2C_SLAVE
  87 #define CONFIG_SYS_I2C_SLAVE    0xfe
  88 #endif
  89
  90 /*
  91  * Initialization, must be called once on start up, may be called
  92  * repeatedly to change the speed and slave addresses.
  93  */
  94 void i2c_init(int speed, int slaveaddr);
  95 void i2c_init_board(void);
  96 #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
  97 void i2c_board_late_init(void);
  98 #endif
  99
 100 #if defined(CONFIG_I2C_MUX)
 101
 102 typedef struct _mux {
 103         uchar   chip;
 104         uchar   channel;
 105         char    *name;
 106         struct _mux     *next;
 107 } I2C_MUX;
 108
 109 typedef struct _mux_device {
 110         int     busid;
 111         I2C_MUX *mux;   /* List of muxes, to reach the device */
 112         struct _mux_device      *next;
 113 } I2C_MUX_DEVICE;
 114
 115 I2C_MUX_DEVICE  *i2c_mux_search_device(int id);
 116 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf);
 117 int i2x_mux_select_mux(int bus);
 118 int i2c_mux_ident_muxstring_f (uchar *buf);
 119 #endif
 120
 121 /*
 122  * Probe the given I2C chip address.  Returns 0 if a chip responded,
 123  * not 0 on failure.
 124  */
 125 int i2c_probe(uchar chip);
 126
 127 /*
 128  * Read/Write interface:
 129  *   chip:    I2C chip address, range 0..127
 130  *   addr:    Memory (register) address within the chip
 131  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 132  *              memories, 0 for register type devices with only one
 133  *              register)
 134  *   buffer:  Where to read/write the data
 135  *   len:     How many bytes to read/write
 136  *
 137  *   Returns: 0 on success, not 0 on failure
 138  */
 139 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
 140 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
 141
 142 /*
 143  * Utility routines to read/write registers.
 144  */
 145 static inline u8 i2c_reg_read(u8 addr, u8 reg)
 146 {
 147         u8 buf;
 148
 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
 154 #ifdef DEBUG
 155         printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
 156 #endif
 157
 158         i2c_read(addr, reg, 1, &buf, 1);
 159
 160         return buf;
 161 }
 162
 163 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
 164 {
 165 #ifdef CONFIG_8xx
 166         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 167         i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 168 #endif
 169
 170 #ifdef DEBUG
 171         printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 172                __func__, addr, reg, val);
 173 #endif
 174
 175         i2c_write(addr, reg, 1, &val, 1);
 176 }
 177
 178 /*
 179  * Functions for setting the current I2C bus and its speed
 180  */
 181
 182 /*
 183  * i2c_set_bus_num:
 184  *
 185  *  Change the active I2C bus.  Subsequent read/write calls will
 186  *  go to this one.
 187  *
 188  *      bus - bus index, zero based
 189  *
 190  *      Returns: 0 on success, not 0 on failure
 191  *
 192  */
 193 int i2c_set_bus_num(unsigned int bus);
 194
 195 /*
 196  * i2c_get_bus_num:
 197  *
 198  *  Returns index of currently active I2C bus.  Zero-based.
 199  */
 200
 201 unsigned int i2c_get_bus_num(void);
 202
 203 /*
 204  * i2c_set_bus_speed:
 205  *
 206  *  Change the speed of the active I2C bus
 207  *
 208  *      speed - bus speed in Hz
 209  *
 210  *      Returns: 0 on success, not 0 on failure
 211  *
 212  */
 213 int i2c_set_bus_speed(unsigned int);
 214
 215 /*
 216  * i2c_get_bus_speed:
 217  *
 218  *  Returns speed of currently active I2C bus in Hz
 219  */
 220
 221 unsigned int i2c_get_bus_speed(void);
 222
 223 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
 224 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
 225 static inline unsigned int I2C_GET_BUS(void)
 226 {
 227         return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
 228 }
 229
 230 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
 231 static inline void I2C_SET_BUS(unsigned int bus)
 232 {
 233         if (I2C_MULTI_BUS)
 234                 i2c_set_bus_num(bus);
 235 }
 236
 237 /* Multi I2C definitions */
 238 enum {
 239         I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
 240         I2C_8, I2C_9, I2C_10,
 241 };
 242
 243 /* Multi I2C busses handling */
 244 #ifdef CONFIG_SOFT_I2C_MULTI_BUS
 245 extern int get_multi_scl_pin(void);
 246 extern int get_multi_sda_pin(void);
 247 extern int multi_i2c_init(void);
 248 #endif
 249
 250 /**
 251  * Get FDT values for i2c bus.
 252  *
 253  * @param blob  Device tree blbo
 254  * @return the number of I2C bus
 255  */
 256 void board_i2c_init(const void *blob);
 257
 258 /**
 259  * Find the I2C bus number by given a FDT I2C node.
 260  *
 261  * @param blob  Device tree blbo
 262  * @param node  FDT I2C node to find
 263  * @return the number of I2C bus (zero based), or -1 on error
 264  */
 265 int i2c_get_bus_num_fdt(int node);
 266
 267 /**
 268  * Reset the I2C bus represented by the given a FDT I2C node.
 269  *
 270  * @param blob  Device tree blbo
 271  * @param node  FDT I2C node to find
 272  * @return 0 if port was reset, -1 if not found
 273  */
 274 int i2c_reset_port_fdt(const void *blob, int node);
 275 #endif  /* _I2C_H_ */