Skip to content
Snippets Groups Projects
i2c.h 6.78 KiB
Newer Older
  • Learn to ignore specific revisions
  • Wolfgang Denk's avatar
    Wolfgang Denk committed
    /*
     * (C) Copyright 2001
     * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
     *
     * See file CREDITS for list of people who contributed to this
     * project.
     *
     * This program is free software; you can redistribute it and/or
     * modify it under the terms of the GNU General Public License as
     * published by the Free Software Foundation; either version 2 of
     * the License, or (at your option) any later version.
     *
     * This program is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * You should have received a copy of the GNU General Public License
     * along with this program; if not, write to the Free Software
     * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
     * MA 02111-1307 USA
     *
     * The original I2C interface was
     *   (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
     *   AIRVENT SAM s.p.a - RIMINI(ITALY)
     * but has been changed substantially.
     */
    
    #ifndef _I2C_H_
    #define _I2C_H_
    
    /*
     * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
     *
     * The implementation MUST NOT use static or global variables if the
     * I2C routines are used to read SDRAM configuration information
     * because this is done before the memories are initialized. Limited
     * use of stack-based variables are OK (the initial stack size is
     * limited).
     *
     * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
     */
    
    /*
     * Configuration items.
     */
    #define I2C_RXTX_LEN	128	/* maximum tx/rx buffer length */
    
    
    #ifdef	CONFIG_I2C_MULTI_BUS
    #define	MAX_I2C_BUS			2
    #define	I2C_MULTI_BUS			1
    
    #define	MAX_I2C_BUS			1
    #define	I2C_MULTI_BUS			0
    #endif
    
    #if !defined(CONFIG_SYS_MAX_I2C_BUS)
    #define CONFIG_SYS_MAX_I2C_BUS		MAX_I2C_BUS
    
    /* define the I2C bus number for RTC and DTT if not already done */
    
    #if !defined(CONFIG_SYS_RTC_BUS_NUM)
    #define CONFIG_SYS_RTC_BUS_NUM		0
    
    #if !defined(CONFIG_SYS_DTT_BUS_NUM)
    #define CONFIG_SYS_DTT_BUS_NUM		0
    
    #if !defined(CONFIG_SYS_SPD_BUS_NUM)
    #define CONFIG_SYS_SPD_BUS_NUM		0
    
    #ifndef I2C_SOFT_DECLARATIONS
    # if defined(CONFIG_MPC8260)
    
    #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
    
    #  define I2C_SOFT_DECLARATIONS	volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
    
    
    # elif (defined(CONFIG_AT91RM9200) || \
    	defined(CONFIG_AT91SAM9260) ||  defined(CONFIG_AT91SAM9261) || \
    	defined(CONFIG_AT91SAM9263)) && !defined(CONFIG_AT91_LEGACY)
    
    #  define I2C_SOFT_DECLARATIONS	at91_pio_t *pio	= (at91_pio_t *) ATMEL_BASE_PIOA;
    
    # else
    #  define I2C_SOFT_DECLARATIONS
    # endif
    #endif
    
    /* Set default value for the I2C bus speed on 8xx. In the
    
     * future, we'll define these in all 8xx board config files.
     */
    #ifndef	CONFIG_SYS_I2C_SPEED
    #define	CONFIG_SYS_I2C_SPEED	50000
    #endif
    
    /*
     * Many boards/controllers/drivers don't support an I2C slave interface so
     * provide a default slave address for them for use in common code.  A real
     * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
     * support a slave interface.
     */
    
    #define	CONFIG_SYS_I2C_SLAVE	0xfe
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
    /*
     * Initialization, must be called once on start up, may be called
     * repeatedly to change the speed and slave addresses.
     */
    void i2c_init(int speed, int slaveaddr);
    
    #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
    void i2c_board_late_init(void);
    #endif
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
    
    
    #if defined(CONFIG_I2C_MUX)
    
    typedef struct _mux {
    	uchar	chip;
    	uchar	channel;
    	char	*name;
    	struct _mux	*next;
    } I2C_MUX;
    
    typedef struct _mux_device {
    	int	busid;
    	I2C_MUX	*mux;	/* List of muxes, to reach the device */
    	struct _mux_device	*next;
    } I2C_MUX_DEVICE;
    
    I2C_MUX_DEVICE	*i2c_mux_search_device(int id);
    I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf);
    int i2x_mux_select_mux(int bus);
    int i2c_mux_ident_muxstring_f (uchar *buf);
    #endif
    
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
    /*
     * Probe the given I2C chip address.  Returns 0 if a chip responded,
     * not 0 on failure.
     */
    int i2c_probe(uchar chip);
    
    /*
     * Read/Write interface:
     *   chip:    I2C chip address, range 0..127
     *   addr:    Memory (register) address within the chip
     *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
     *              memories, 0 for register type devices with only one
     *              register)
     *   buffer:  Where to read/write the data
     *   len:     How many bytes to read/write
     *
     *   Returns: 0 on success, not 0 on failure
     */
    int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
    int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
    
    /*
     * Utility routines to read/write registers.
     */
    
    static inline u8 i2c_reg_read(u8 addr, u8 reg)
    {
    	u8 buf;
    
    #ifdef CONFIG_8xx
    	/* MPC8xx needs this.  Maybe one day we can get rid of it. */
    	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
    #endif
    
    #ifdef DEBUG
    	printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
    #endif
    
    	i2c_read(addr, reg, 1, &buf, 1);
    
    	return buf;
    }
    
    static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
    {
    #ifdef CONFIG_8xx
    	/* MPC8xx needs this.  Maybe one day we can get rid of it. */
    	i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
    #endif
    
    #ifdef DEBUG
    	printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
    	       __func__, addr, reg, val);
    #endif
    
    	i2c_write(addr, reg, 1, &val, 1);
    }
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
    
    
    /*
     * Functions for setting the current I2C bus and its speed
     */
    
    /*
     * i2c_set_bus_num:
     *
     *  Change the active I2C bus.  Subsequent read/write calls will
     *  go to this one.
     *
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
     *	bus - bus index, zero based
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
     *	Returns: 0 on success, not 0 on failure
    
    
    /*
     * i2c_get_bus_num:
     *
     *  Returns index of currently active I2C bus.  Zero-based.
     */
    
    
    
    /*
     * i2c_set_bus_speed:
     *
     *  Change the speed of the active I2C bus
     *
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
     *	speed - bus speed in Hz
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
     *	Returns: 0 on success, not 0 on failure
    
    
    /*
     * i2c_get_bus_speed:
     *
     *  Returns speed of currently active I2C bus in Hz
     */
    
    
    /* NOTE: These two functions MUST be always_inline to avoid code growth! */
    static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
    static inline unsigned int I2C_GET_BUS(void)
    {
    	return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
    }
    
    static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
    static inline void I2C_SET_BUS(unsigned int bus)
    {
    	if (I2C_MULTI_BUS)
    		i2c_set_bus_num(bus);
    }
    
    
    /* Multi I2C definitions */
    enum {
    	I2C_0, I2C_1, I2C_2, I2C_3, I2C_4, I2C_5, I2C_6, I2C_7,
    	I2C_8, I2C_9, I2C_10,
    };
    
    /* Multi I2C busses handling */
    #ifdef CONFIG_SOFT_I2C_MULTI_BUS
    extern int get_multi_scl_pin(void);
    extern int get_multi_sda_pin(void);
    extern int multi_i2c_init(void);
    #endif
    
    Wolfgang Denk's avatar
    Wolfgang Denk committed
    #endif	/* _I2C_H_ */