From 26bf7deca364a5b33f39e8f14ddd3f4081345015 Mon Sep 17 00:00:00 2001 From: Aubrey Li Date: Mon, 19 Mar 2007 01:24:52 +0800 Subject: [Blackfin][PATCH] Add BF537 stamp board support --- cpu/bf537/i2c.c | 460 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 460 insertions(+) create mode 100644 cpu/bf537/i2c.c (limited to 'cpu/bf537/i2c.c') diff --git a/cpu/bf537/i2c.c b/cpu/bf537/i2c.c new file mode 100644 index 0000000..3b0d026 --- /dev/null +++ b/cpu/bf537/i2c.c @@ -0,0 +1,460 @@ +/**************************************************************** + * $ID: i2c.c 24 Oct 2006 12:00:00 +0800 $ * + * * + * Description: * + * * + * Maintainer: sonicz * + * * + * CopyRight (c) 2006 Analog Device * + * All rights reserved. * + * * + * This file is free software; * + * you are free to modify and/or redistribute it * + * under the terms of the GNU General Public Licence (GPL).* + * * + ****************************************************************/ + +#include + +#ifdef CONFIG_HARD_I2C + +#include +#include +#include + +#define bfin_read16(addr) ({ unsigned __v; \ + __asm__ __volatile__ (\ + "%0 = w[%1] (z);\n\t"\ + : "=d"(__v) : "a"(addr)); (unsigned short)__v; }) + +#define bfin_write16(addr,val) ({\ + __asm__ __volatile__ (\ + "w[%0] = %1;\n\t"\ + : : "a"(addr) , "d"(val) : "memory");}) + +/* Two-Wire Interface (0xFFC01400 - 0xFFC014FF) */ +#define bfin_read_TWI_CLKDIV() bfin_read16(TWI_CLKDIV) +#define bfin_write_TWI_CLKDIV(val) bfin_write16(TWI_CLKDIV,val) +#define bfin_read_TWI_CONTROL() bfin_read16(TWI_CONTROL) +#define bfin_write_TWI_CONTROL(val) bfin_write16(TWI_CONTROL,val) +#define bfin_read_TWI_SLAVE_CTL() bfin_read16(TWI_SLAVE_CTL) +#define bfin_write_TWI_SLAVE_CTL(val) bfin_write16(TWI_SLAVE_CTL,val) +#define bfin_read_TWI_SLAVE_STAT() bfin_read16(TWI_SLAVE_STAT) +#define bfin_write_TWI_SLAVE_STAT(val) bfin_write16(TWI_SLAVE_STAT,val) +#define bfin_read_TWI_SLAVE_ADDR() bfin_read16(TWI_SLAVE_ADDR) +#define bfin_write_TWI_SLAVE_ADDR(val) bfin_write16(TWI_SLAVE_ADDR,val) +#define bfin_read_TWI_MASTER_CTL() bfin_read16(TWI_MASTER_CTL) +#define bfin_write_TWI_MASTER_CTL(val) bfin_write16(TWI_MASTER_CTL,val) +#define bfin_read_TWI_MASTER_STAT() bfin_read16(TWI_MASTER_STAT) +#define bfin_write_TWI_MASTER_STAT(val) bfin_write16(TWI_MASTER_STAT,val) +#define bfin_read_TWI_MASTER_ADDR() bfin_read16(TWI_MASTER_ADDR) +#define bfin_write_TWI_MASTER_ADDR(val) bfin_write16(TWI_MASTER_ADDR,val) +#define bfin_read_TWI_INT_STAT() bfin_read16(TWI_INT_STAT) +#define bfin_write_TWI_INT_STAT(val) bfin_write16(TWI_INT_STAT,val) +#define bfin_read_TWI_INT_MASK() bfin_read16(TWI_INT_MASK) +#define bfin_write_TWI_INT_MASK(val) bfin_write16(TWI_INT_MASK,val) +#define bfin_read_TWI_FIFO_CTL() bfin_read16(TWI_FIFO_CTL) +#define bfin_write_TWI_FIFO_CTL(val) bfin_write16(TWI_FIFO_CTL,val) +#define bfin_read_TWI_FIFO_STAT() bfin_read16(TWI_FIFO_STAT) +#define bfin_write_TWI_FIFO_STAT(val) bfin_write16(TWI_FIFO_STAT,val) +#define bfin_read_TWI_XMT_DATA8() bfin_read16(TWI_XMT_DATA8) +#define bfin_write_TWI_XMT_DATA8(val) bfin_write16(TWI_XMT_DATA8,val) +#define bfin_read_TWI_XMT_DATA16() bfin_read16(TWI_XMT_DATA16) +#define bfin_write_TWI_XMT_DATA16(val) bfin_write16(TWI_XMT_DATA16,val) +#define bfin_read_TWI_RCV_DATA8() bfin_read16(TWI_RCV_DATA8) +#define bfin_write_TWI_RCV_DATA8(val) bfin_write16(TWI_RCV_DATA8,val) +#define bfin_read_TWI_RCV_DATA16() bfin_read16(TWI_RCV_DATA16) +#define bfin_write_TWI_RCV_DATA16(val) bfin_write16(TWI_RCV_DATA16,val) + +#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); + sync(); + + /* 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); + sync(); +} + +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); + sync(); + /* Clear status */ + bfin_write_TWI_INT_STAT(XMTSERV); + sync(); + 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); + sync(); + } + /* Clear interrupt source */ + bfin_write_TWI_INT_STAT(RCVSERV); + sync(); + 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); + sync(); + /* + * 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); + sync(); + /* + * 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); + sync(); + bfin_write_TWI_INT_MASK(0); + bfin_write_TWI_MASTER_CTL(0); + sync(); + 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) ; + + /* 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); + sync(); + bfin_write_TWI_FIFO_CTL(0); + sync(); + + 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--; + sync(); + } + } + + /* 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)); + sync(); + + 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)); + sync(); + + 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; + +} + +uchar i2c_reg_read(uchar chip, uchar reg) +{ + uchar buf; + + PRINTD("i2c_reg_read: chip=0x%02x, reg=0x%02x\n", chip, reg); + i2c_read(chip, reg, 0, &buf, 1); + return (buf); +} + +void i2c_reg_write(uchar chip, uchar reg, uchar val) +{ + PRINTD("i2c_reg_write: chip=0x%02x, reg=0x%02x, val=0x%02x\n", chip, + reg, val); + i2c_write(chip, reg, 0, &val, 1); +} + +#endif /* CONFIG_HARD_I2C */ -- cgit v1.1