diff options
Diffstat (limited to 'cpu/blackfin/i2c.c')
-rw-r--r-- | cpu/blackfin/i2c.c | 428 |
1 files changed, 0 insertions, 428 deletions
diff --git a/cpu/blackfin/i2c.c b/cpu/blackfin/i2c.c deleted file mode 100644 index 2a3e223..0000000 --- a/cpu/blackfin/i2c.c +++ /dev/null @@ -1,428 +0,0 @@ -/* - * i2c.c - driver for Blackfin on-chip TWI/I2C - * - * Copyright (c) 2006-2008 Analog Devices Inc. - * - * Licensed under the GPL-2 or later. - */ - -#include <common.h> - -#ifdef CONFIG_HARD_I2C - -#include <asm/blackfin.h> -#include <i2c.h> -#include <asm/io.h> -#include <asm/mach-common/bits/twi.h> - -/* Two-Wire Interface (0xFFC01400 - 0xFFC014FF) */ -#ifdef TWI0_CLKDIV -#define bfin_read_TWI_CLKDIV() bfin_read_TWI0_CLKDIV() -#define bfin_write_TWI_CLKDIV(val) bfin_write_TWI0_CLKDIV(val) -#define bfin_read_TWI_CONTROL() bfin_read_TWI0_CONTROL() -#define bfin_write_TWI_CONTROL(val) bfin_write_TWI0_CONTROL(val) -#define bfin_read_TWI_SLAVE_CTL() bfin_read_TWI0_SLAVE_CTL() -#define bfin_write_TWI_SLAVE_CTL(val) bfin_write_TWI0_SLAVE_CTL(val) -#define bfin_read_TWI_SLAVE_STAT() bfin_read_TWI0_SLAVE_STAT() -#define bfin_write_TWI_SLAVE_STAT(val) bfin_write_TWI0_SLAVE_STAT(val) -#define bfin_read_TWI_SLAVE_ADDR() bfin_read_TWI0_SLAVE_ADDR() -#define bfin_write_TWI_SLAVE_ADDR(val) bfin_write_TWI0_SLAVE_ADDR(val) -#define bfin_read_TWI_MASTER_CTL() bfin_read_TWI0_MASTER_CTL() -#define bfin_write_TWI_MASTER_CTL(val) bfin_write_TWI0_MASTER_CTL(val) -#define bfin_read_TWI_MASTER_STAT() bfin_read_TWI0_MASTER_STAT() -#define bfin_write_TWI_MASTER_STAT(val) bfin_write_TWI0_MASTER_STAT(val) -#define bfin_read_TWI_MASTER_ADDR() bfin_read_TWI0_MASTER_ADDR() -#define bfin_write_TWI_MASTER_ADDR(val) bfin_write_TWI0_MASTER_ADDR(val) -#define bfin_read_TWI_INT_STAT() bfin_read_TWI0_INT_STAT() -#define bfin_write_TWI_INT_STAT(val) bfin_write_TWI0_INT_STAT(val) -#define bfin_read_TWI_INT_MASK() bfin_read_TWI0_INT_MASK() -#define bfin_write_TWI_INT_MASK(val) bfin_write_TWI0_INT_MASK(val) -#define bfin_read_TWI_FIFO_CTL() bfin_read_TWI0_FIFO_CTL() -#define bfin_write_TWI_FIFO_CTL(val) bfin_write_TWI0_FIFO_CTL(val) -#define bfin_read_TWI_FIFO_STAT() bfin_read_TWI0_FIFO_STAT() -#define bfin_write_TWI_FIFO_STAT(val) bfin_write_TWI0_FIFO_STAT(val) -#define bfin_read_TWI_XMT_DATA8() bfin_read_TWI0_XMT_DATA8() -#define bfin_write_TWI_XMT_DATA8(val) bfin_write_TWI0_XMT_DATA8(val) -#define bfin_read_TWI_XMT_DATA_16() bfin_read_TWI0_XMT_DATA16() -#define bfin_write_TWI_XMT_DATA16(val) bfin_write_TWI0_XMT_DATA16(val) -#define bfin_read_TWI_RCV_DATA8() bfin_read_TWI0_RCV_DATA8() -#define bfin_write_TWI_RCV_DATA8(val) bfin_write_TWI0_RCV_DATA8(val) -#define bfin_read_TWI_RCV_DATA16() bfin_read_TWI0_RCV_DATA16() -#define bfin_write_TWI_RCV_DATA16(val) bfin_write_TWI0_RCV_DATA16(val) -#endif - -#ifdef DEBUG_I2C -#define PRINTD(fmt,args...) do { \ - DECLARE_GLOBAL_DATA_PTR; \ - if (gd->have_console) \ - printf(fmt ,##args); \ - } while (0) -#else -#define PRINTD(fmt,args...) -#endif - -#ifndef CONFIG_TWICLK_KHZ -#define CONFIG_TWICLK_KHZ 50 -#endif - -/* All transfers are described by this data structure */ -struct i2c_msg { - u16 addr; /* slave address */ - u16 flags; -#define I2C_M_STOP 0x2 -#define I2C_M_RD 0x1 - u16 len; /* msg length */ - u8 *buf; /* pointer to msg data */ -}; - -/** - * i2c_reset: - reset the host controller - */ -static void i2c_reset(void) -{ - /* Disable TWI */ - bfin_write_TWI_CONTROL(0); - SSYNC(); - - /* Set TWI internal clock as 10MHz */ - bfin_write_TWI_CONTROL(((get_sclk() / 1024 / 1024 + 5) / 10) & 0x7F); - - /* Set Twi interface clock as specified */ - if (CONFIG_TWICLK_KHZ > 400) - bfin_write_TWI_CLKDIV(((5 * 1024 / 400) << 8) | ((5 * 1024 / - 400) & 0xFF)); - else - bfin_write_TWI_CLKDIV(((5 * 1024 / - CONFIG_TWICLK_KHZ) << 8) | ((5 * 1024 / - CONFIG_TWICLK_KHZ) - & 0xFF)); - - /* Enable TWI */ - bfin_write_TWI_CONTROL(bfin_read_TWI_CONTROL() | TWI_ENA); - SSYNC(); -} - -int wait_for_completion(struct i2c_msg *msg, int timeout_count) -{ - unsigned short twi_int_stat; - unsigned short mast_stat; - int i; - - for (i = 0; i < timeout_count; i++) { - twi_int_stat = bfin_read_TWI_INT_STAT(); - mast_stat = bfin_read_TWI_MASTER_STAT(); - - if (XMTSERV & twi_int_stat) { - /* Transmit next data */ - if (msg->len > 0) { - bfin_write_TWI_XMT_DATA8(*(msg->buf++)); - msg->len--; - } else if (msg->flags & I2C_M_STOP) - bfin_write_TWI_MASTER_CTL - (bfin_read_TWI_MASTER_CTL() | STOP); - SSYNC(); - /* Clear status */ - bfin_write_TWI_INT_STAT(XMTSERV); - SSYNC(); - i = 0; - } - if (RCVSERV & twi_int_stat) { - if (msg->len > 0) { - /* Receive next data */ - *(msg->buf++) = bfin_read_TWI_RCV_DATA8(); - msg->len--; - } else if (msg->flags & I2C_M_STOP) { - bfin_write_TWI_MASTER_CTL - (bfin_read_TWI_MASTER_CTL() | STOP); - SSYNC(); - } - /* Clear interrupt source */ - bfin_write_TWI_INT_STAT(RCVSERV); - SSYNC(); - i = 0; - } - if (MERR & twi_int_stat) { - bfin_write_TWI_INT_STAT(MERR); - bfin_write_TWI_INT_MASK(0); - bfin_write_TWI_MASTER_STAT(0x3e); - bfin_write_TWI_MASTER_CTL(0); - SSYNC(); - /* - * if both err and complete int stats are set, - * return proper results. - */ - if (MCOMP & twi_int_stat) { - bfin_write_TWI_INT_STAT(MCOMP); - bfin_write_TWI_INT_MASK(0); - bfin_write_TWI_MASTER_CTL(0); - SSYNC(); - /* - * If it is a quick transfer, - * only address bug no data, not an err. - */ - if (msg->len == 0 && mast_stat & BUFRDERR) - return 0; - /* - * If address not acknowledged return -3, - * else return 0. - */ - else if (!(mast_stat & ANAK)) - return 0; - else - return -3; - } - return -1; - } - if (MCOMP & twi_int_stat) { - bfin_write_TWI_INT_STAT(MCOMP); - SSYNC(); - bfin_write_TWI_INT_MASK(0); - bfin_write_TWI_MASTER_CTL(0); - SSYNC(); - return 0; - } - } - if (msg->flags & I2C_M_RD) - return -4; - else - return -2; -} - -/** - * i2c_transfer: - Transfer one byte over the i2c bus - * - * This function can tranfer a byte over the i2c bus in both directions. - * It is used by the public API functions. - * - * @return: 0: transfer successful - * -1: transfer fail - * -2: transmit timeout - * -3: ACK missing - * -4: receive timeout - * -5: controller not ready - */ -int i2c_transfer(struct i2c_msg *msg) -{ - int ret = 0; - int timeout_count = 10000; - int len = msg->len; - - if (!(bfin_read_TWI_CONTROL() & TWI_ENA)) { - ret = -5; - goto transfer_error; - } - - while (bfin_read_TWI_MASTER_STAT() & BUSBUSY) - continue; - - /* Set Transmit device address */ - bfin_write_TWI_MASTER_ADDR(msg->addr); - - /* - * FIFO Initiation. - * Data in FIFO should be discarded before start a new operation. - */ - bfin_write_TWI_FIFO_CTL(0x3); - SSYNC(); - bfin_write_TWI_FIFO_CTL(0); - SSYNC(); - - if (!(msg->flags & I2C_M_RD)) { - /* Transmit first data */ - if (msg->len > 0) { - PRINTD("1 in i2c_transfer: buf=%d, len=%d\n", *msg->buf, - len); - bfin_write_TWI_XMT_DATA8(*(msg->buf++)); - msg->len--; - SSYNC(); - } - } - - /* clear int stat */ - bfin_write_TWI_INT_STAT(MERR | MCOMP | XMTSERV | RCVSERV); - - /* Interrupt mask . Enable XMT, RCV interrupt */ - bfin_write_TWI_INT_MASK(MCOMP | MERR | - ((msg->flags & I2C_M_RD) ? RCVSERV : XMTSERV)); - SSYNC(); - - if (len > 0 && len <= 255) - bfin_write_TWI_MASTER_CTL((len << 6)); - else if (msg->len > 255) { - bfin_write_TWI_MASTER_CTL((0xff << 6)); - msg->flags &= I2C_M_STOP; - } else - bfin_write_TWI_MASTER_CTL(0); - - /* Master enable */ - bfin_write_TWI_MASTER_CTL(bfin_read_TWI_MASTER_CTL() | MEN | - ((msg->flags & I2C_M_RD) - ? MDIR : 0) | ((CONFIG_TWICLK_KHZ > - 100) ? FAST : 0)); - SSYNC(); - - ret = wait_for_completion(msg, timeout_count); - PRINTD("3 in i2c_transfer: ret=%d\n", ret); - - transfer_error: - switch (ret) { - case 1: - PRINTD(("i2c_transfer: error: transfer fail\n")); - break; - case 2: - PRINTD(("i2c_transfer: error: transmit timeout\n")); - break; - case 3: - PRINTD(("i2c_transfer: error: ACK missing\n")); - break; - case 4: - PRINTD(("i2c_transfer: error: receive timeout\n")); - break; - case 5: - PRINTD(("i2c_transfer: error: controller not ready\n")); - i2c_reset(); - break; - default: - break; - } - return ret; - -} - -/* ---------------------------------------------------------------------*/ -/* API Functions */ -/* ---------------------------------------------------------------------*/ - -void i2c_init(int speed, int slaveaddr) -{ - i2c_reset(); -} - -/** - * i2c_probe: - Test if a chip answers for a given i2c address - * - * @chip: address of the chip which is searched for - * @return: 0 if a chip was found, -1 otherwhise - */ - -int i2c_probe(uchar chip) -{ - struct i2c_msg msg; - u8 probebuf; - - i2c_reset(); - - probebuf = 0; - msg.addr = chip; - msg.flags = 0; - msg.len = 1; - msg.buf = &probebuf; - if (i2c_transfer(&msg)) - return -1; - - msg.addr = chip; - msg.flags = I2C_M_RD; - msg.len = 1; - msg.buf = &probebuf; - if (i2c_transfer(&msg)) - return -1; - - return 0; -} - -/** - * i2c_read: - Read multiple bytes from an i2c device - * - * 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) -{ - struct i2c_msg msg; - u8 addr_bytes[3]; /* lowest...highest byte of data address */ - - PRINTD("i2c_read: chip=0x%x, addr=0x%x, alen=0x%x, len=0x%x\n", chip, - addr, alen, len); - - if (alen > 0) { - addr_bytes[0] = (u8) ((addr >> 0) & 0x000000FF); - addr_bytes[1] = (u8) ((addr >> 8) & 0x000000FF); - addr_bytes[2] = (u8) ((addr >> 16) & 0x000000FF); - msg.addr = chip; - msg.flags = 0; - msg.len = alen; - msg.buf = addr_bytes; - if (i2c_transfer(&msg)) - return -1; - } - - /* start read sequence */ - PRINTD(("i2c_read: start read sequence\n")); - msg.addr = chip; - msg.flags = I2C_M_RD; - msg.len = len; - msg.buf = buffer; - if (i2c_transfer(&msg)) - return -1; - - return 0; -} - -/** - * i2c_write: - Write multiple bytes to an i2c device - * - * 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_write(uchar chip, uint addr, int alen, uchar * buffer, int len) -{ - struct i2c_msg msg; - u8 addr_bytes[3]; /* lowest...highest byte of data address */ - - PRINTD - ("i2c_write: chip=0x%x, addr=0x%x, alen=0x%x, len=0x%x, buf0=0x%x\n", - chip, addr, alen, len, buffer[0]); - - /* chip address write */ - if (alen > 0) { - addr_bytes[0] = (u8) ((addr >> 0) & 0x000000FF); - addr_bytes[1] = (u8) ((addr >> 8) & 0x000000FF); - addr_bytes[2] = (u8) ((addr >> 16) & 0x000000FF); - msg.addr = chip; - msg.flags = 0; - msg.len = alen; - msg.buf = addr_bytes; - if (i2c_transfer(&msg)) - return -1; - } - - /* start read sequence */ - PRINTD(("i2c_write: start write sequence\n")); - msg.addr = chip; - msg.flags = 0; - msg.len = len; - msg.buf = buffer; - if (i2c_transfer(&msg)) - return -1; - - return 0; - -} - -#endif /* CONFIG_HARD_I2C */ |