/* * (C) Copyright 2004, Freescale, Inc * TsiChung Liew, Tsi-Chung.Liew@freescale.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 */ #include <common.h> DECLARE_GLOBAL_DATA_PTR; #ifdef CONFIG_HARD_I2C #include <mpc8220.h> #include <i2c.h> typedef struct mpc8220_i2c { volatile u32 adr; /* I2Cn + 0x00 */ volatile u32 fdr; /* I2Cn + 0x04 */ volatile u32 cr; /* I2Cn + 0x08 */ volatile u32 sr; /* I2Cn + 0x0C */ volatile u32 dr; /* I2Cn + 0x10 */ } i2c_t; /* I2Cn control register bits */ #define I2C_EN 0x80 #define I2C_IEN 0x40 #define I2C_STA 0x20 #define I2C_TX 0x10 #define I2C_TXAK 0x08 #define I2C_RSTA 0x04 #define I2C_INIT_MASK (I2C_EN | I2C_STA | I2C_TX | I2C_RSTA) /* I2Cn status register bits */ #define I2C_CF 0x80 #define I2C_AAS 0x40 #define I2C_BB 0x20 #define I2C_AL 0x10 #define I2C_SRW 0x04 #define I2C_IF 0x02 #define I2C_RXAK 0x01 #define I2C_TIMEOUT 100 #define I2C_RETRIES 1 struct mpc8220_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; 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) { i2c_t *regs = (i2c_t *) MMAP_I2C; int timeout = I2C_TIMEOUT; int status; status = mpc_reg_in (®s->sr); while (timeout-- && (status & I2C_BB)) { #if 1 volatile int temp; mpc_reg_out (®s->cr, I2C_STA, I2C_STA); temp = mpc_reg_in (®s->dr); mpc_reg_out (®s->cr, 0, I2C_STA); mpc_reg_out (®s->cr, 0, 0); mpc_reg_out (®s->cr, I2C_EN, 0); #endif udelay (1000); status = mpc_reg_in (®s->sr); } return (status & I2C_BB); } static int wait_for_pin (int *status) { i2c_t *regs = (i2c_t *) MMAP_I2C; int timeout = I2C_TIMEOUT; *status = mpc_reg_in (®s->sr); while (timeout-- && !(*status & I2C_IF)) { udelay (1000); *status = mpc_reg_in (®s->sr); } if (!(*status & I2C_IF)) { return -1; } mpc_reg_out (®s->sr, 0, I2C_IF); return 0; } static int do_address (uchar chip, char rdwr_flag) { i2c_t *regs = (i2c_t *) MMAP_I2C; int status; chip <<= 1; if (rdwr_flag) chip |= 1; mpc_reg_out (®s->cr, I2C_TX, I2C_TX); mpc_reg_out (®s->dr, 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) { i2c_t *regs = (i2c_t *) MMAP_I2C; int wrcount; int status; for (wrcount = 0; wrcount < len; ++wrcount) { mpc_reg_out (®s->dr, buf[wrcount], 0); if (wait_for_pin (&status)) break; if (status & I2C_RXAK) break; } return !(wrcount == len); return 0; } static int receive_bytes (uchar chip, char *buf, int len) { i2c_t *regs = (i2c_t *) MMAP_I2C; int dummy = 1; int rdcount = 0; int status; int i; mpc_reg_out (®s->cr, 0, I2C_TX); for (i = 0; i < len; ++i) { buf[rdcount] = mpc_reg_in (®s->dr); if (dummy) dummy = 0; else rdcount++; if (wait_for_pin (&status)) return -4; } mpc_reg_out (®s->cr, I2C_TXAK, I2C_TXAK); buf[rdcount++] = mpc_reg_in (®s->dr); if (wait_for_pin (&status)) return -5; mpc_reg_out (®s->cr, 0, I2C_TXAK); return 0; } /**************** I2C API ****************/ void i2c_init (int speed, int saddr) { i2c_t *regs = (i2c_t *) MMAP_I2C; mpc_reg_out (®s->cr, 0, 0); mpc_reg_out (®s->adr, saddr << 1, 0); /* Set clock */ mpc_reg_out (®s->fdr, mpc_get_fdr (speed), 0); /* Enable module */ mpc_reg_out (®s->cr, I2C_EN, I2C_INIT_MASK); mpc_reg_out (®s->sr, 0, I2C_IF); return; } static int mpc_get_fdr (int speed) { static int fdr = -1; if (fdr == -1) { ulong best_speed = 0; ulong divider; ulong ipb, 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 mpc8220_i2c_tap scltap[] = { {4, 1}, {4, 2}, {6, 4}, {6, 8}, {14, 16}, {30, 32}, {62, 64}, {126, 128} }; ipb = gd->bus_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 (ipb <= speed * scl) { if ((speed * scl - ipb) < bestmatch) { bestmatch = speed * scl - ipb; best_i = i; best_j = j; best_speed = ipb / scl; } } } } divider = (best_i & 3) | ((best_i & 4) << 3) | (best_j << 2); if (gd->flags & GD_FLG_RELOC) { fdr = divider; } else { printf ("%ld kHz, ", best_speed / 1000); return divider; } } return fdr; } int i2c_probe (uchar chip) { i2c_t *regs = (i2c_t *) MMAP_I2C; int i; for (i = 0; i < I2C_RETRIES; i++) { mpc_reg_out (®s->cr, I2C_STA, I2C_STA); if (!do_address (chip, 0)) { mpc_reg_out (®s->cr, 0, I2C_STA); break; } mpc_reg_out (®s->cr, 0, I2C_STA); udelay (50); } return (i == I2C_RETRIES); } int i2c_read (uchar chip, uint addr, int alen, uchar * buf, int len) { uchar xaddr[4]; i2c_t *regs = (i2c_t *) MMAP_I2C; 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->cr, I2C_STA, I2C_STA); if (do_address (chip, 0)) { printf ("i2c_read: failed to address chip\n"); goto Done; } if (send_bytes (chip, (char *)&xaddr[4 - alen], alen)) { printf ("i2c_read: send_bytes failed\n"); goto Done; } mpc_reg_out (®s->cr, 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->cr, 0, I2C_STA); return ret; } int i2c_write (uchar chip, uint addr, int alen, uchar * buf, int len) { uchar xaddr[4]; i2c_t *regs = (i2c_t *) MMAP_I2C; 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->cr, I2C_STA, I2C_STA); if (do_address (chip, 0)) { printf ("i2c_write: failed to address chip\n"); goto Done; } if (send_bytes (chip, (char *)&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->cr, 0, I2C_STA); return ret; } #endif /* CONFIG_HARD_I2C */