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| -rw-r--r-- | src/include/device/i2c.h | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/src/include/device/i2c.h b/src/include/device/i2c.h new file mode 100644 index 0000000000..f1275e38af --- /dev/null +++ b/src/include/device/i2c.h @@ -0,0 +1,279 @@ +/* + * (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 +#else +#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 +#endif + +/* 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 +#endif +#if !defined(CONFIG_SYS_DTT_BUS_NUM) +#define CONFIG_SYS_DTT_BUS_NUM 0 +#endif +#if !defined(CONFIG_SYS_SPD_BUS_NUM) +#define CONFIG_SYS_SPD_BUS_NUM 0 +#endif + +#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); +# elif defined(CONFIG_8xx) +# 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 + +#ifdef CONFIG_8xx +/* 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 +#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. + */ +#ifndef CONFIG_SYS_I2C_SLAVE +#define CONFIG_SYS_I2C_SLAVE 0xfe +#endif + +/* + * 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); +void i2c_init_board(void); +#ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT +void i2c_board_late_init(void); +#endif + +#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 + +/* + * 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); +} + +/* + * 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. + * + * bus - bus index, zero based + * + * Returns: 0 on success, not 0 on failure + * + */ +int i2c_set_bus_num(unsigned int bus); + +/* + * i2c_get_bus_num: + * + * Returns index of currently active I2C bus. Zero-based. + */ + +unsigned int i2c_get_bus_num(void); + +/* + * i2c_set_bus_speed: + * + * Change the speed of the active I2C bus + * + * speed - bus speed in Hz + * + * Returns: 0 on success, not 0 on failure + * + */ +int i2c_set_bus_speed(unsigned int); + +/* + * i2c_get_bus_speed: + * + * Returns speed of currently active I2C bus in Hz + */ + +unsigned int i2c_get_bus_speed(void); + +/* 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); +} + +/* + * Set an early register base for a given i2c peripheral. + * This is used to access a single i2c bus early on in the boot sequence. + * + * @param base: The base address of the i2c peripheral's register map + */ +void i2c_set_early_reg(unsigned int base); + +/** + * Find the I2C bus number by given a FDT I2C node. + * + * @param blob Device tree blbo + * @param node FDT I2C node to find + * @return the number of I2C bus (zero based), or -1 on error + */ +int i2c_get_bus_num_fdt(const void *blob, int node); + +/** + * Reset the I2C bus represented by the given a FDT I2C node. + * + * @param blob Device tree blbo + * @param node FDT I2C node to find + * @return 0 if port was reset, -1 if not found + */ +int i2c_reset_port_fdt(const void *blob, int node); + +#endif /* _I2C_H_ */ |