projects / people / ms / u-boot.git / blame
| Commit | Line | Data |
|---|---|---|
| cc54a0f7 TK |
1 | /* |
| 2 | * Copyright (C) 2012 Boundary Devices Inc. | |
| 3 | * | |
| 1a459660 | 4 | * SPDX-License-Identifier: GPL-2.0+ |
| cc54a0f7 TK |
5 | */ |
| 6 | #include <common.h> | |
| 7 | #include <asm/arch/clock.h> | |
| 8 | #include <asm/arch/imx-regs.h> | |
| 9 | #include <asm/errno.h> | |
| 10 | #include <asm/gpio.h> | |
| 11 | #include <asm/imx-common/mxc_i2c.h> | |
| 12 | #include <watchdog.h> | |
| 13 | ||
| 14 | static int force_idle_bus(void *priv) | |
| 15 | { | |
| 16 | int i; | |
| 17 | int sda, scl; | |
| 18 | ulong elapsed, start_time; | |
| 19 | struct i2c_pads_info *p = (struct i2c_pads_info *)priv; | |
| 20 | int ret = 0; | |
| 21 | ||
| 22 | gpio_direction_input(p->sda.gp); | |
| 23 | gpio_direction_input(p->scl.gp); | |
| 24 | ||
| 25 | imx_iomux_v3_setup_pad(p->sda.gpio_mode); | |
| 26 | imx_iomux_v3_setup_pad(p->scl.gpio_mode); | |
| 27 | ||
| 28 | sda = gpio_get_value(p->sda.gp); | |
| 29 | scl = gpio_get_value(p->scl.gp); | |
| 30 | if ((sda & scl) == 1) | |
| 31 | goto exit; /* Bus is idle already */ | |
| 32 | ||
| 33 | printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__, | |
| 34 | sda, scl, p->sda.gp, p->scl.gp); | |
| 35 | /* Send high and low on the SCL line */ | |
| 36 | for (i = 0; i < 9; i++) { | |
| 37 | gpio_direction_output(p->scl.gp, 0); | |
| 38 | udelay(50); | |
| 39 | gpio_direction_input(p->scl.gp); | |
| 40 | udelay(50); | |
| 41 | } | |
| 42 | start_time = get_timer(0); | |
| 43 | for (;;) { | |
| 44 | sda = gpio_get_value(p->sda.gp); | |
| 45 | scl = gpio_get_value(p->scl.gp); | |
| 46 | if ((sda & scl) == 1) | |
| 47 | break; | |
| 48 | WATCHDOG_RESET(); | |
| 49 | elapsed = get_timer(start_time); | |
| 50 | if (elapsed > (CONFIG_SYS_HZ / 5)) { /* .2 seconds */ | |
| 51 | ret = -EBUSY; | |
| 52 | printf("%s: failed to clear bus, sda=%d scl=%d\n", | |
| 53 | __func__, sda, scl); | |
| 54 | break; | |
| 55 | } | |
| 56 | } | |
| 57 | exit: | |
| 58 | imx_iomux_v3_setup_pad(p->sda.i2c_mode); | |
| 59 | imx_iomux_v3_setup_pad(p->scl.i2c_mode); | |
| 60 | return ret; | |
| 61 | } | |
| 62 | ||
| 63 | static void * const i2c_bases[] = { | |
| 64 | (void *)I2C1_BASE_ADDR, | |
| 65 | (void *)I2C2_BASE_ADDR, | |
| 66 | #ifdef I2C3_BASE_ADDR | |
| 67 | (void *)I2C3_BASE_ADDR, | |
| 68 | #endif | |
| 69 | }; | |
| 70 | ||
| 71 | /* i2c_index can be from 0 - 2 */ | |
| 72 | void setup_i2c(unsigned i2c_index, int speed, int slave_addr, | |
| 73 | struct i2c_pads_info *p) | |
| 74 | { | |
| 75 | if (i2c_index >= ARRAY_SIZE(i2c_bases)) | |
| 76 | return; | |
| 77 | /* Enable i2c clock */ | |
| 78 | enable_i2c_clk(1, i2c_index); | |
| 79 | /* Make sure bus is idle */ | |
| 80 | force_idle_bus(p); | |
| 81 | bus_i2c_init(i2c_bases[i2c_index], speed, slave_addr, | |
| 82 | force_idle_bus, p); | |
| 83 | } |