/* * (C) Copyright 2000 * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it * * (C) Copyright 2000 Sysgo Real-Time Solutions, GmbH <www.elinos.com> * Marius Groeger <mgroeger@sysgo.de> * * (C) Copyright 2003 Pengutronix e.K. * Robert Schwebel <r.schwebel@pengutronix.de> * * (C) Copyright 2011 Marvell Inc. * Lei Wen <leiwen@marvell.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 * * Back ported to the 8xx platform (from the 8260 platform) by * Murray.Jensen@cmst.csiro.au, 27-Jan-01. */ #include <common.h> #include <asm/io.h> #ifdef CONFIG_HARD_I2C #include <i2c.h> #include "mv_i2c.h" #ifdef DEBUG_I2C #define PRINTD(x) printf x #else #define PRINTD(x) #endif /* All transfers are described by this data structure */ struct i2c_msg { u8 condition; u8 acknack; u8 direction; u8 data; }; struct mv_i2c { u32 ibmr; u32 pad0; u32 idbr; u32 pad1; u32 icr; u32 pad2; u32 isr; u32 pad3; u32 isar; }; static struct mv_i2c *base; static void i2c_board_init(struct mv_i2c *base) { #ifdef CONFIG_SYS_I2C_INIT_BOARD u32 icr; /* * call board specific i2c bus reset routine before accessing the * environment, which might be in a chip on that bus. For details * about this problem see doc/I2C_Edge_Conditions. * * disable I2C controller first, otherwhise it thinks we want to * talk to the slave port... */ icr = readl(&base->icr); writel(readl(&base->icr) & ~(ICR_SCLE | ICR_IUE), &base->icr); i2c_init_board(); writel(icr, &base->icr); #endif } #ifdef CONFIG_I2C_MULTI_BUS static u32 i2c_regs[CONFIG_MV_I2C_NUM] = CONFIG_MV_I2C_REG; static unsigned int bus_initialized[CONFIG_MV_I2C_NUM]; static unsigned int current_bus; int i2c_set_bus_num(unsigned int bus) { if ((bus < 0) || (bus >= CONFIG_MV_I2C_NUM)) { printf("Bad bus: %d\n", bus); return -1; } base = (struct mv_i2c *)i2c_regs[bus]; current_bus = bus; if (!bus_initialized[current_bus]) { i2c_board_init(base); bus_initialized[current_bus] = 1; } return 0; } unsigned int i2c_get_bus_num(void) { return current_bus; } #endif /* * i2c_reset: - reset the host controller * */ static void i2c_reset(void) { writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */ writel(readl(&base->icr) | ICR_UR, &base->icr); /* reset the unit */ udelay(100); writel(readl(&base->icr) & ~ICR_IUE, &base->icr); /* disable unit */ i2c_clk_enable(); writel(CONFIG_SYS_I2C_SLAVE, &base->isar); /* set our slave address */ writel(I2C_ICR_INIT, &base->icr); /* set control reg values */ writel(I2C_ISR_INIT, &base->isr); /* set clear interrupt bits */ writel(readl(&base->icr) | ICR_IUE, &base->icr); /* enable unit */ udelay(100); } /* * i2c_isr_set_cleared: - wait until certain bits of the I2C status register * are set and cleared * * @return: 1 in case of success, 0 means timeout (no match within 10 ms). */ static int i2c_isr_set_cleared(unsigned long set_mask, unsigned long cleared_mask) { int timeout = 1000, isr; do { isr = readl(&base->isr); udelay(10); if (timeout-- < 0) return 0; } while (((isr & set_mask) != set_mask) || ((isr & cleared_mask) != 0)); return 1; } /* * 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: message is empty * -2: transmit timeout * -3: ACK missing * -4: receive timeout * -5: illegal parameters * -6: bus is busy and couldn't be aquired */ int i2c_transfer(struct i2c_msg *msg) { int ret; if (!msg) goto transfer_error_msg_empty; switch (msg->direction) { case I2C_WRITE: /* check if bus is not busy */ if (!i2c_isr_set_cleared(0, ISR_IBB)) goto transfer_error_bus_busy; /* start transmission */ writel(readl(&base->icr) & ~ICR_START, &base->icr); writel(readl(&base->icr) & ~ICR_STOP, &base->icr); writel(msg->data, &base->idbr); if (msg->condition == I2C_COND_START) writel(readl(&base->icr) | ICR_START, &base->icr); if (msg->condition == I2C_COND_STOP) writel(readl(&base->icr) | ICR_STOP, &base->icr); if (msg->acknack == I2C_ACKNAK_SENDNAK) writel(readl(&base->icr) | ICR_ACKNAK, &base->icr); if (msg->acknack == I2C_ACKNAK_SENDACK) writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr); writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr); writel(readl(&base->icr) | ICR_TB, &base->icr); /* transmit register empty? */ if (!i2c_isr_set_cleared(ISR_ITE, 0)) goto transfer_error_transmit_timeout; /* clear 'transmit empty' state */ writel(readl(&base->isr) | ISR_ITE, &base->isr); /* wait for ACK from slave */ if (msg->acknack == I2C_ACKNAK_WAITACK) if (!i2c_isr_set_cleared(0, ISR_ACKNAK)) goto transfer_error_ack_missing; break; case I2C_READ: /* check if bus is not busy */ if (!i2c_isr_set_cleared(0, ISR_IBB)) goto transfer_error_bus_busy; /* start receive */ writel(readl(&base->icr) & ~ICR_START, &base->icr); writel(readl(&base->icr) & ~ICR_STOP, &base->icr); if (msg->condition == I2C_COND_START) writel(readl(&base->icr) | ICR_START, &base->icr); if (msg->condition == I2C_COND_STOP) writel(readl(&base->icr) | ICR_STOP, &base->icr); if (msg->acknack == I2C_ACKNAK_SENDNAK) writel(readl(&base->icr) | ICR_ACKNAK, &base->icr); if (msg->acknack == I2C_ACKNAK_SENDACK) writel(readl(&base->icr) & ~ICR_ACKNAK, &base->icr); writel(readl(&base->icr) & ~ICR_ALDIE, &base->icr); writel(readl(&base->icr) | ICR_TB, &base->icr); /* receive register full? */ if (!i2c_isr_set_cleared(ISR_IRF, 0)) goto transfer_error_receive_timeout; msg->data = readl(&base->idbr); /* clear 'receive empty' state */ writel(readl(&base->isr) | ISR_IRF, &base->isr); break; default: goto transfer_error_illegal_param; } return 0; transfer_error_msg_empty: PRINTD(("i2c_transfer: error: 'msg' is empty\n")); ret = -1; goto i2c_transfer_finish; transfer_error_transmit_timeout: PRINTD(("i2c_transfer: error: transmit timeout\n")); ret = -2; goto i2c_transfer_finish; transfer_error_ack_missing: PRINTD(("i2c_transfer: error: ACK missing\n")); ret = -3; goto i2c_transfer_finish; transfer_error_receive_timeout: PRINTD(("i2c_transfer: error: receive timeout\n")); ret = -4; goto i2c_transfer_finish; transfer_error_illegal_param: PRINTD(("i2c_transfer: error: illegal parameters\n")); ret = -5; goto i2c_transfer_finish; transfer_error_bus_busy: PRINTD(("i2c_transfer: error: bus is busy\n")); ret = -6; goto i2c_transfer_finish; i2c_transfer_finish: PRINTD(("i2c_transfer: ISR: 0x%04x\n", readl(&base->isr))); i2c_reset(); return ret; } /* ------------------------------------------------------------------------ */ /* API Functions */ /* ------------------------------------------------------------------------ */ void i2c_init(int speed, int slaveaddr) { #ifdef CONFIG_I2C_MULTI_BUS current_bus = 0; base = (struct mv_i2c *)i2c_regs[current_bus]; #else base = (struct mv_i2c *)CONFIG_MV_I2C_REG; #endif i2c_board_init(base); } /* * 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; i2c_reset(); msg.condition = I2C_COND_START; msg.acknack = I2C_ACKNAK_WAITACK; msg.direction = I2C_WRITE; msg.data = (chip << 1) + 1; if (i2c_transfer(&msg)) return -1; msg.condition = I2C_COND_STOP; msg.acknack = I2C_ACKNAK_SENDNAK; msg.direction = I2C_READ; msg.data = 0x00; if (i2c_transfer(&msg)) return -1; return 0; } /* * i2c_read: - Read multiple bytes from an i2c device * * The higher level routines take into account that this function is only * called with len < page length of the device (see configuration file) * * @chip: address of the chip which is to be read * @addr: i2c data address within the chip * @alen: length of the i2c data address (1..2 bytes) * @buffer: where to write the data * @len: how much byte do we want to read * @return: 0 in case of success */ 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%02x, addr=0x%02x, alen=0x%02x, " "len=0x%02x)\n", chip, addr, alen, len)); i2c_reset(); /* dummy chip address write */ PRINTD(("i2c_read: dummy chip address write\n")); msg.condition = I2C_COND_START; msg.acknack = I2C_ACKNAK_WAITACK; msg.direction = I2C_WRITE; msg.data = (chip << 1); msg.data &= 0xFE; if (i2c_transfer(&msg)) return -1; /* * send memory address bytes; * alen defines how much bytes we have to send. */ /*addr &= ((1 << CONFIG_SYS_EEPROM_PAGE_WRITE_BITS)-1); */ addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF); addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF); addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF); while (--alen >= 0) { PRINTD(("i2c_read: send memory word address byte %1d\n", alen)); msg.condition = I2C_COND_NORMAL; msg.acknack = I2C_ACKNAK_WAITACK; msg.direction = I2C_WRITE; msg.data = addr_bytes[alen]; if (i2c_transfer(&msg)) return -1; } /* start read sequence */ PRINTD(("i2c_read: start read sequence\n")); msg.condition = I2C_COND_START; msg.acknack = I2C_ACKNAK_WAITACK; msg.direction = I2C_WRITE; msg.data = (chip << 1); msg.data |= 0x01; if (i2c_transfer(&msg)) return -1; /* read bytes; send NACK at last byte */ while (len--) { if (len == 0) { msg.condition = I2C_COND_STOP; msg.acknack = I2C_ACKNAK_SENDNAK; } else { msg.condition = I2C_COND_NORMAL; msg.acknack = I2C_ACKNAK_SENDACK; } msg.direction = I2C_READ; msg.data = 0x00; if (i2c_transfer(&msg)) return -1; *buffer = msg.data; PRINTD(("i2c_read: reading byte (0x%08x)=0x%02x\n", (unsigned int)buffer, *buffer)); buffer++; } i2c_reset(); return 0; } /* * i2c_write: - Write multiple bytes to an i2c device * * The higher level routines take into account that this function is only * called with len < page length of the device (see configuration file) * * @chip: address of the chip which is to be written * @addr: i2c data address within the chip * @alen: length of the i2c data address (1..2 bytes) * @buffer: where to find the data to be written * @len: how much byte do we want to read * @return: 0 in case of success */ 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%02x, addr=0x%02x, alen=0x%02x, " "len=0x%02x)\n", chip, addr, alen, len)); i2c_reset(); /* chip address write */ PRINTD(("i2c_write: chip address write\n")); msg.condition = I2C_COND_START; msg.acknack = I2C_ACKNAK_WAITACK; msg.direction = I2C_WRITE; msg.data = (chip << 1); msg.data &= 0xFE; if (i2c_transfer(&msg)) return -1; /* * send memory address bytes; * alen defines how much bytes we have to send. */ addr_bytes[0] = (u8)((addr >> 0) & 0x000000FF); addr_bytes[1] = (u8)((addr >> 8) & 0x000000FF); addr_bytes[2] = (u8)((addr >> 16) & 0x000000FF); while (--alen >= 0) { PRINTD(("i2c_write: send memory word address\n")); msg.condition = I2C_COND_NORMAL; msg.acknack = I2C_ACKNAK_WAITACK; msg.direction = I2C_WRITE; msg.data = addr_bytes[alen]; if (i2c_transfer(&msg)) return -1; } /* write bytes; send NACK at last byte */ while (len--) { PRINTD(("i2c_write: writing byte (0x%08x)=0x%02x\n", (unsigned int)buffer, *buffer)); if (len == 0) msg.condition = I2C_COND_STOP; else msg.condition = I2C_COND_NORMAL; msg.acknack = I2C_ACKNAK_WAITACK; msg.direction = I2C_WRITE; msg.data = *(buffer++); if (i2c_transfer(&msg)) return -1; } i2c_reset(); return 0; } #endif /* CONFIG_HARD_I2C */