/* * (C) Copyright 2003 - 2007 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. * * 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 * * Based on the MPC5xxx code. */ #include <common.h> DECLARE_GLOBAL_DATA_PTR; #ifdef CONFIG_HARD_I2C #include <mpc512x.h> #include <i2c.h> #define immr ((immap_t *)CFG_IMMR) /* by default set I2C bus 0 active */ static unsigned int bus_num = 0; #define I2C_TIMEOUT 100 #define I2C_RETRIES 3 struct mpc512x_i2c_tap { int scl2tap; int tap2tap; }; static int mpc_reg_in(volatile u32 *reg); static void mpc_reg_out(volatile u32 *reg, int val, int mask); static int wait_for_bb(void); static int wait_for_pin(int *status); static int do_address(uchar chip, char rdwr_flag); static int send_bytes(uchar chip, char *buf, int len); static int receive_bytes(uchar chip, char *buf, int len); static int mpc_get_fdr(int); static int mpc_reg_in (volatile u32 *reg) { int ret = *reg >> 24; __asm__ __volatile__ ("eieio"); return ret; } static void mpc_reg_out (volatile u32 *reg, int val, int mask) { int tmp; if (!mask) { *reg = val << 24; } else { tmp = mpc_reg_in (reg); *reg = ((tmp & ~mask) | (val & mask)) << 24; } __asm__ __volatile__ ("eieio"); return; } static int wait_for_bb (void) { i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int timeout = I2C_TIMEOUT; int status; status = mpc_reg_in (®s->msr); while (timeout-- && (status & I2C_BB)) { volatile int temp; mpc_reg_out (®s->mcr, I2C_STA, I2C_STA); temp = mpc_reg_in (®s->mdr); mpc_reg_out (®s->mcr, 0, I2C_STA); mpc_reg_out (®s->mcr, 0, 0); mpc_reg_out (®s->mcr, I2C_EN, 0); udelay (1000); status = mpc_reg_in (®s->msr); } return (status & I2C_BB); } static int wait_for_pin (int *status) { i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int timeout = I2C_TIMEOUT; *status = mpc_reg_in (®s->msr); while (timeout-- && !(*status & I2C_IF)) { udelay (1000); *status = mpc_reg_in (®s->msr); } if (!(*status & I2C_IF)) { return -1; } mpc_reg_out (®s->msr, 0, I2C_IF); return 0; } static int do_address (uchar chip, char rdwr_flag) { i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int status; chip <<= 1; if (rdwr_flag) { chip |= 1; } mpc_reg_out (®s->mcr, I2C_TX, I2C_TX); mpc_reg_out (®s->mdr, chip, 0); if (wait_for_pin (&status)) { return -2; } if (status & I2C_RXAK) { return -3; } return 0; } static int send_bytes (uchar chip, char *buf, int len) { i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int wrcount; int status; for (wrcount = 0; wrcount < len; ++wrcount) { mpc_reg_out (®s->mdr, buf[wrcount], 0); if (wait_for_pin (&status)) { break; } if (status & I2C_RXAK) { break; } } return !(wrcount == len); } static int receive_bytes (uchar chip, char *buf, int len) { i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int dummy = 1; int rdcount = 0; int status; int i; mpc_reg_out (®s->mcr, 0, I2C_TX); for (i = 0; i < len; ++i) { buf[rdcount] = mpc_reg_in (®s->mdr); if (dummy) { dummy = 0; } else { rdcount++; } if (wait_for_pin (&status)) { return -4; } } mpc_reg_out (®s->mcr, I2C_TXAK, I2C_TXAK); buf[rdcount++] = mpc_reg_in (®s->mdr); if (wait_for_pin (&status)) { return -5; } mpc_reg_out (®s->mcr, 0, I2C_TXAK); return 0; } /**************** I2C API ****************/ void i2c_init (int speed, int saddr) { int i; for(i = 0; i < I2C_BUS_CNT; i++){ i2c512x_dev_t *regs = &immr->i2c.dev[i]; mpc_reg_out (®s->mcr, 0, 0); /* Set clock */ mpc_reg_out (®s->mfdr, mpc_get_fdr (speed), 0); mpc_reg_out (®s->madr, saddr << 1, 0); /* Enable module */ mpc_reg_out (®s->mcr, I2C_EN, I2C_INIT_MASK); mpc_reg_out (®s->msr, 0, I2C_IF); } /* Disable interrupts */ immr->i2c.icr = 0; /* Turn off filters */ immr->i2c.mifr = 0; return; } static int mpc_get_fdr (int speed) { static int fdr = -1; if (fdr == -1) { ulong best_speed = 0; ulong divider; ulong ips, scl; ulong bestmatch = 0xffffffffUL; int best_i = 0, best_j = 0, i, j; int SCL_Tap[] = { 9, 10, 12, 15, 5, 6, 7, 8}; struct mpc512x_i2c_tap scltap[] = { {4, 1}, {4, 2}, {6, 4}, {6, 8}, {14, 16}, {30, 32}, {62, 64}, {126, 128} }; ips = gd->ips_clk; for (i = 7; i >= 0; i--) { for (j = 7; j >= 0; j--) { scl = 2 * (scltap[j].scl2tap + (SCL_Tap[i] - 1) * scltap[j].tap2tap + 2); if (ips <= speed*scl) { if ((speed*scl - ips) < bestmatch) { bestmatch = speed*scl - ips; best_i = i; best_j = j; best_speed = ips/scl; } } } } divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2); if (gd->flags & GD_FLG_RELOC) { fdr = divider; } else { debug("%ld kHz, \n", best_speed / 1000); return divider; } } return fdr; } int i2c_probe (uchar chip) { i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int i; for (i = 0; i < I2C_RETRIES; i++) { mpc_reg_out (®s->mcr, I2C_STA, I2C_STA); if (! do_address (chip, 0)) { mpc_reg_out (®s->mcr, 0, I2C_STA); udelay (500); break; } mpc_reg_out (®s->mcr, 0, I2C_STA); udelay (500); } return (i == I2C_RETRIES); } int i2c_read (uchar chip, uint addr, int alen, uchar *buf, int len) { char xaddr[4]; i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int ret = -1; xaddr[0] = (addr >> 24) & 0xFF; xaddr[1] = (addr >> 16) & 0xFF; xaddr[2] = (addr >> 8) & 0xFF; xaddr[3] = addr & 0xFF; if (wait_for_bb ()) { printf ("i2c_read: bus is busy\n"); goto Done; } mpc_reg_out (®s->mcr, I2C_STA, I2C_STA); if (do_address (chip, 0)) { printf ("i2c_read: failed to address chip\n"); goto Done; } if (send_bytes (chip, &xaddr[4-alen], alen)) { printf ("i2c_read: send_bytes failed\n"); goto Done; } mpc_reg_out (®s->mcr, I2C_RSTA, I2C_RSTA); if (do_address (chip, 1)) { printf ("i2c_read: failed to address chip\n"); goto Done; } if (receive_bytes (chip, (char *)buf, len)) { printf ("i2c_read: receive_bytes failed\n"); goto Done; } ret = 0; Done: mpc_reg_out (®s->mcr, 0, I2C_STA); return ret; } int i2c_write (uchar chip, uint addr, int alen, uchar *buf, int len) { char xaddr[4]; i2c512x_dev_t *regs = &immr->i2c.dev[bus_num]; int ret = -1; xaddr[0] = (addr >> 24) & 0xFF; xaddr[1] = (addr >> 16) & 0xFF; xaddr[2] = (addr >> 8) & 0xFF; xaddr[3] = addr & 0xFF; if (wait_for_bb ()) { printf ("i2c_write: bus is busy\n"); goto Done; } mpc_reg_out (®s->mcr, I2C_STA, I2C_STA); if (do_address (chip, 0)) { printf ("i2c_write: failed to address chip\n"); goto Done; } if (send_bytes (chip, &xaddr[4-alen], alen)) { printf ("i2c_write: send_bytes failed\n"); goto Done; } if (send_bytes (chip, (char *)buf, len)) { printf ("i2c_write: send_bytes failed\n"); goto Done; } ret = 0; Done: mpc_reg_out (®s->mcr, 0, I2C_STA); return ret; } uchar i2c_reg_read (uchar chip, uchar reg) { uchar buf; i2c_read (chip, reg, 1, &buf, 1); return buf; } void i2c_reg_write (uchar chip, uchar reg, uchar val) { i2c_write (chip, reg, 1, &val, 1); return; } int i2c_set_bus_num (unsigned int bus) { if (bus >= I2C_BUS_CNT) { return -1; } bus_num = bus; return 0; } unsigned int i2c_get_bus_num (void) { return bus_num; } /* TODO */ unsigned int i2c_get_bus_speed (void) { return -1; } int i2c_set_bus_speed (unsigned int speed) { if (speed != CFG_I2C_SPEED) return -1; return 0; } #endif /* CONFIG_HARD_I2C */