diff options
Diffstat (limited to 'cpu/mpc512x/i2c.c')
| -rw-r--r-- | cpu/mpc512x/i2c.c | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/cpu/mpc512x/i2c.c b/cpu/mpc512x/i2c.c new file mode 100644 index 0000000..00e28d6 --- /dev/null +++ b/cpu/mpc512x/i2c.c @@ -0,0 +1,431 @@ +/* + * (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 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 mpc512x_i2c_tap scltap[] = { + {4, 1}, + {4, 2}, + {6, 4}, + {6, 8}, + {14, 16}, + {30, 32}, + {62, 64}, + {126, 128} + }; + + ipb = gd->ipb_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 { + 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 */ |