diff options
| -rw-r--r-- | drivers/i2c/adi_i2c.c | 387 |
1 files changed, 0 insertions, 387 deletions
diff --git a/drivers/i2c/adi_i2c.c b/drivers/i2c/adi_i2c.c deleted file mode 100644 index 675f417..0000000 --- a/drivers/i2c/adi_i2c.c +++ /dev/null @@ -1,387 +0,0 @@ -/* - * i2c.c - driver for ADI TWI/I2C - * - * Copyright (c) 2006-2013 Analog Devices Inc. - * - * Licensed under the GPL-2 or later. - */ - -#include <common.h> -#include <i2c.h> - -#include <asm/clock.h> -#include <asm/twi.h> -#include <asm/io.h> - -/* Every register is 32bit aligned, but only 16bits in size */ -#define ureg(name) u16 name; u16 __pad_##name; -struct twi_regs { - ureg(clkdiv); - ureg(control); - ureg(slave_ctl); - ureg(slave_stat); - ureg(slave_addr); - ureg(master_ctl); - ureg(master_stat); - ureg(master_addr); - ureg(int_stat); - ureg(int_mask); - ureg(fifo_ctl); - ureg(fifo_stat); - char __pad[0x50]; - ureg(xmt_data8); - ureg(xmt_data16); - ureg(rcv_data8); - ureg(rcv_data16); -}; -#undef ureg - -/* U-Boot I2C framework allows only one active device at a time. */ -#ifdef TWI_CLKDIV -#define TWI0_CLKDIV TWI_CLKDIV -#endif -static struct twi_regs *twi = (void *)TWI0_CLKDIV; - -#ifdef DEBUG -# define dmemset(s, c, n) memset(s, c, n) -#else -# define dmemset(s, c, n) -#endif -#define debugi(fmt, args...) \ - debug( \ - "MSTAT:0x%03x FSTAT:0x%x ISTAT:0x%02x\t%-20s:%-3i: " fmt "\n", \ - twi->master_stat, twi->fifo_stat, twi->int_stat, \ - __func__, __LINE__, ## args) - -#ifdef CONFIG_TWICLK_KHZ -# error do not define CONFIG_TWICLK_KHZ ... use CONFIG_SYS_I2C_SPEED -#endif - -/* - * The way speed is changed into duty often results in integer truncation - * with 50% duty, so we'll force rounding up to the next duty by adding 1 - * to the max. In practice this will get us a speed of something like - * 385 KHz. The other limit is easy to handle as it is only 8 bits. - */ -#define I2C_SPEED_MAX 400000 -#define I2C_SPEED_TO_DUTY(speed) (5000000 / (speed)) -#define I2C_DUTY_MAX (I2C_SPEED_TO_DUTY(I2C_SPEED_MAX) + 1) -#define I2C_DUTY_MIN 0xff /* 8 bit limited */ -#define SYS_I2C_DUTY I2C_SPEED_TO_DUTY(CONFIG_SYS_I2C_SPEED) -/* Note: duty is inverse of speed, so the comparisons below are correct */ -#if SYS_I2C_DUTY < I2C_DUTY_MAX || SYS_I2C_DUTY > I2C_DUTY_MIN -# error "The Blackfin I2C hardware can only operate 20KHz - 400KHz" -#endif - -/* All transfers are described by this data structure */ -struct i2c_msg { - u8 flags; -#define I2C_M_COMBO 0x4 -#define I2C_M_STOP 0x2 -#define I2C_M_READ 0x1 - int len; /* msg length */ - u8 *buf; /* pointer to msg data */ - int alen; /* addr length */ - u8 *abuf; /* addr buffer */ -}; - -/* Allow msec timeout per ~byte transfer */ -#define I2C_TIMEOUT 10 - -/** - * wait_for_completion - manage the actual i2c transfer - * @msg: the i2c msg - */ -static int wait_for_completion(struct i2c_msg *msg) -{ - u16 int_stat, ctl; - ulong timebase = get_timer(0); - - do { - int_stat = readw(&twi->int_stat); - - if (int_stat & XMTSERV) { - debugi("processing XMTSERV"); - writew(XMTSERV, &twi->int_stat); - if (msg->alen) { - writew(*(msg->abuf++), &twi->xmt_data8); - --msg->alen; - } else if (!(msg->flags & I2C_M_COMBO) && msg->len) { - writew(*(msg->buf++), &twi->xmt_data8); - --msg->len; - } else { - ctl = readw(&twi->master_ctl); - if (msg->flags & I2C_M_COMBO) - writew(ctl | RSTART | MDIR, - &twi->master_ctl); - else - writew(ctl | STOP, &twi->master_ctl); - } - } - if (int_stat & RCVSERV) { - debugi("processing RCVSERV"); - writew(RCVSERV, &twi->int_stat); - if (msg->len) { - *(msg->buf++) = readw(&twi->rcv_data8); - --msg->len; - } else if (msg->flags & I2C_M_STOP) { - ctl = readw(&twi->master_ctl); - writew(ctl | STOP, &twi->master_ctl); - } - } - if (int_stat & MERR) { - debugi("processing MERR"); - writew(MERR, &twi->int_stat); - return msg->len; - } - if (int_stat & MCOMP) { - debugi("processing MCOMP"); - writew(MCOMP, &twi->int_stat); - if (msg->flags & I2C_M_COMBO && msg->len) { - ctl = readw(&twi->master_ctl); - ctl = (ctl & ~RSTART) | - (min(msg->len, 0xff) << 6) | MEN | MDIR; - writew(ctl, &twi->master_ctl); - } else - break; - } - - /* If we were able to do something, reset timeout */ - if (int_stat) - timebase = get_timer(0); - - } while (get_timer(timebase) < I2C_TIMEOUT); - - return msg->len; -} - -/** - * i2c_transfer - setup an i2c transfer - * @return: 0 if things worked, non-0 if things failed - * - * Here we just get the i2c stuff all prepped and ready, and then tail off - * into wait_for_completion() for all the bits to go. - */ -static int i2c_transfer(uchar chip, uint addr, int alen, uchar *buffer, - int len, u8 flags) -{ - int ret; - u16 ctl; - uchar addr_buffer[] = { - (addr >> 0), - (addr >> 8), - (addr >> 16), - }; - struct i2c_msg msg = { - .flags = flags | (len >= 0xff ? I2C_M_STOP : 0), - .buf = buffer, - .len = len, - .abuf = addr_buffer, - .alen = alen, - }; - - dmemset(buffer, 0xff, len); - debugi("chip=0x%x addr=0x%02x alen=%i buf[0]=0x%02x len=%i ", - chip, addr, alen, buffer[0], len); - debugi("flags=0x%02x[%s] ", flags, - (flags & I2C_M_READ ? "rd" : "wr")); - - /* wait for things to settle */ - while (readw(&twi->master_stat) & BUSBUSY) - if (ctrlc()) - return 1; - - /* Set Transmit device address */ - writew(chip, &twi->master_addr); - - /* Clear the FIFO before starting things */ - writew(XMTFLUSH | RCVFLUSH, &twi->fifo_ctl); - writew(0, &twi->fifo_ctl); - - /* prime the pump */ - if (msg.alen) { - len = (msg.flags & I2C_M_COMBO) ? msg.alen : msg.alen + len; - debugi("first byte=0x%02x", *msg.abuf); - writew(*(msg.abuf++), &twi->xmt_data8); - --msg.alen; - } else if (!(msg.flags & I2C_M_READ) && msg.len) { - debugi("first byte=0x%02x", *msg.buf); - writew(*(msg.buf++), &twi->xmt_data8); - --msg.len; - } - - /* clear int stat */ - writew(-1, &twi->master_stat); - writew(-1, &twi->int_stat); - writew(0, &twi->int_mask); - - /* Master enable */ - ctl = readw(&twi->master_ctl); - ctl = (ctl & FAST) | (min(len, 0xff) << 6) | MEN | - ((msg.flags & I2C_M_READ) ? MDIR : 0); - writew(ctl, &twi->master_ctl); - - /* process the rest */ - ret = wait_for_completion(&msg); - debugi("ret=%d", ret); - - if (ret) { - ctl = readw(&twi->master_ctl) & ~MEN; - writew(ctl, &twi->master_ctl); - ctl = readw(&twi->control) & ~TWI_ENA; - writew(ctl, &twi->control); - ctl = readw(&twi->control) | TWI_ENA; - writew(ctl, &twi->control); - } - - return ret; -} - -/** - * i2c_set_bus_speed - set i2c bus speed - * @speed: bus speed (in HZ) - */ -int i2c_set_bus_speed(unsigned int speed) -{ - u16 clkdiv = I2C_SPEED_TO_DUTY(speed); - - /* Set TWI interface clock */ - if (clkdiv < I2C_DUTY_MAX || clkdiv > I2C_DUTY_MIN) - return -1; - clkdiv = (clkdiv << 8) | (clkdiv & 0xff); - writew(clkdiv, &twi->clkdiv); - - /* Don't turn it on */ - writew(speed > 100000 ? FAST : 0, &twi->master_ctl); - - return 0; -} - -/** - * i2c_get_bus_speed - get i2c bus speed - * @speed: bus speed (in HZ) - */ -unsigned int i2c_get_bus_speed(void) -{ - u16 clkdiv = readw(&twi->clkdiv) & 0xff; - /* 10 MHz / (2 * CLKDIV) -> 5 MHz / CLKDIV */ - return 5000000 / clkdiv; -} - -/** - * i2c_init - initialize the i2c bus - * @speed: bus speed (in HZ) - * @slaveaddr: address of device in slave mode (0 - not slave) - * - * Slave mode isn't actually implemented. It'll stay that way until - * we get a real request for it. - */ -void i2c_init(int speed, int slaveaddr) -{ - u16 prescale = ((get_i2c_clk() / 1000 / 1000 + 5) / 10) & 0x7F; - - /* Set TWI internal clock as 10MHz */ - writew(prescale, &twi->control); - - /* Set TWI interface clock as specified */ - i2c_set_bus_speed(speed); - - /* Enable it */ - writew(TWI_ENA | prescale, &twi->control); - - debugi("CONTROL:0x%04x CLKDIV:0x%04x", readw(&twi->control), - readw(&twi->clkdiv)); - -#if CONFIG_SYS_I2C_SLAVE -# error I2C slave support not tested/supported -#endif -} - -/** - * i2c_probe - test if a chip exists at a given i2c address - * @chip: i2c chip addr to search for - * @return: 0 if found, non-0 if not found - */ -int i2c_probe(uchar chip) -{ - u8 byte; - return i2c_read(chip, 0, 0, &byte, 1); -} - -/** - * i2c_read - read data from an i2c device - * @chip: i2c chip addr - * @addr: memory (register) address in the chip - * @alen: byte size of address - * @buffer: buffer to store data read from chip - * @len: how many bytes to read - * @return: 0 on success, non-0 on failure - */ -int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len) -{ - return i2c_transfer(chip, addr, alen, buffer, - len, (alen ? I2C_M_COMBO : I2C_M_READ)); -} - -/** - * i2c_write - write data to an i2c device - * @chip: i2c chip addr - * @addr: memory (register) address in the chip - * @alen: byte size of address - * @buffer: buffer holding data to write to chip - * @len: how many bytes to write - * @return: 0 on success, non-0 on failure - */ -int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len) -{ - return i2c_transfer(chip, addr, alen, buffer, len, 0); -} - -/** - * i2c_set_bus_num - change active I2C bus - * @bus: bus index, zero based - * @returns: 0 on success, non-0 on failure - */ -int i2c_set_bus_num(unsigned int bus) -{ - switch (bus) { -#if CONFIG_SYS_MAX_I2C_BUS > 0 - case 0: - twi = (void *)TWI0_CLKDIV; - return 0; -#endif -#if CONFIG_SYS_MAX_I2C_BUS > 1 - case 1: - twi = (void *)TWI1_CLKDIV; - return 0; -#endif -#if CONFIG_SYS_MAX_I2C_BUS > 2 - case 2: - twi = (void *)TWI2_CLKDIV; - return 0; -#endif - default: return -1; - } -} - -/** - * i2c_get_bus_num - returns index of active I2C bus - */ -unsigned int i2c_get_bus_num(void) -{ - switch ((unsigned long)twi) { -#if CONFIG_SYS_MAX_I2C_BUS > 0 - case TWI0_CLKDIV: - return 0; -#endif -#if CONFIG_SYS_MAX_I2C_BUS > 1 - case TWI1_CLKDIV: - return 1; -#endif -#if CONFIG_SYS_MAX_I2C_BUS > 2 - case TWI2_CLKDIV: - return 2; -#endif - default: return -1; - } -} |