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Troy Kiskycc54a0f2012-07-19 08:18:25 +00001/*
2 * Copyright (C) 2012 Boundary Devices Inc.
3 *
Wolfgang Denk1a459662013-07-08 09:37:19 +02004 * SPDX-License-Identifier: GPL-2.0+
Troy Kiskycc54a0f2012-07-19 08:18:25 +00005 */
6#include <common.h>
Simon Glassc6f3f322014-10-02 17:17:23 +03007#include <malloc.h>
Troy Kiskycc54a0f2012-07-19 08:18:25 +00008#include <asm/arch/clock.h>
9#include <asm/arch/imx-regs.h>
Masahiro Yamada1221ce42016-09-21 11:28:55 +090010#include <linux/errno.h>
Troy Kiskycc54a0f2012-07-19 08:18:25 +000011#include <asm/gpio.h>
12#include <asm/imx-common/mxc_i2c.h>
13#include <watchdog.h>
14
Peng Fan71204e92015-05-15 07:29:12 +080015int force_idle_bus(void *priv)
Troy Kiskycc54a0f2012-07-19 08:18:25 +000016{
17 int i;
18 int sda, scl;
19 ulong elapsed, start_time;
20 struct i2c_pads_info *p = (struct i2c_pads_info *)priv;
21 int ret = 0;
22
23 gpio_direction_input(p->sda.gp);
24 gpio_direction_input(p->scl.gp);
25
26 imx_iomux_v3_setup_pad(p->sda.gpio_mode);
27 imx_iomux_v3_setup_pad(p->scl.gpio_mode);
28
29 sda = gpio_get_value(p->sda.gp);
30 scl = gpio_get_value(p->scl.gp);
31 if ((sda & scl) == 1)
32 goto exit; /* Bus is idle already */
33
34 printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__,
35 sda, scl, p->sda.gp, p->scl.gp);
36 /* Send high and low on the SCL line */
37 for (i = 0; i < 9; i++) {
38 gpio_direction_output(p->scl.gp, 0);
39 udelay(50);
40 gpio_direction_input(p->scl.gp);
41 udelay(50);
42 }
43 start_time = get_timer(0);
44 for (;;) {
45 sda = gpio_get_value(p->sda.gp);
46 scl = gpio_get_value(p->scl.gp);
47 if ((sda & scl) == 1)
48 break;
49 WATCHDOG_RESET();
50 elapsed = get_timer(start_time);
51 if (elapsed > (CONFIG_SYS_HZ / 5)) { /* .2 seconds */
52 ret = -EBUSY;
53 printf("%s: failed to clear bus, sda=%d scl=%d\n",
54 __func__, sda, scl);
55 break;
56 }
57 }
58exit:
59 imx_iomux_v3_setup_pad(p->sda.i2c_mode);
60 imx_iomux_v3_setup_pad(p->scl.i2c_mode);
61 return ret;
62}
63
64static void * const i2c_bases[] = {
65 (void *)I2C1_BASE_ADDR,
66 (void *)I2C2_BASE_ADDR,
67#ifdef I2C3_BASE_ADDR
68 (void *)I2C3_BASE_ADDR,
69#endif
Heiko Schocher21a26942015-05-18 10:56:24 +020070#ifdef I2C4_BASE_ADDR
71 (void *)I2C4_BASE_ADDR,
72#endif
Troy Kiskycc54a0f2012-07-19 08:18:25 +000073};
74
Heiko Schocher21a26942015-05-18 10:56:24 +020075/* i2c_index can be from 0 - 3 */
Simon Glassedbf8b42014-10-01 19:57:24 -060076int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
77 struct i2c_pads_info *p)
Troy Kiskycc54a0f2012-07-19 08:18:25 +000078{
Marek Vasutcd3c5892014-12-16 14:09:16 +010079 char name[9];
Simon Glassedbf8b42014-10-01 19:57:24 -060080 int ret;
81
Troy Kiskycc54a0f2012-07-19 08:18:25 +000082 if (i2c_index >= ARRAY_SIZE(i2c_bases))
Simon Glassedbf8b42014-10-01 19:57:24 -060083 return -EINVAL;
Simon Glassc6f3f322014-10-02 17:17:23 +030084
Marek Vasutcd3c5892014-12-16 14:09:16 +010085 snprintf(name, sizeof(name), "i2c_sda%01d", i2c_index);
86 ret = gpio_request(p->sda.gp, name);
Simon Glassc6f3f322014-10-02 17:17:23 +030087 if (ret)
Marek Vasutcd3c5892014-12-16 14:09:16 +010088 return ret;
Simon Glassc6f3f322014-10-02 17:17:23 +030089
Marek Vasutcd3c5892014-12-16 14:09:16 +010090 snprintf(name, sizeof(name), "i2c_scl%01d", i2c_index);
91 ret = gpio_request(p->scl.gp, name);
Simon Glassc6f3f322014-10-02 17:17:23 +030092 if (ret)
Marek Vasutcd3c5892014-12-16 14:09:16 +010093 goto err_req;
Simon Glassc6f3f322014-10-02 17:17:23 +030094
Troy Kiskycc54a0f2012-07-19 08:18:25 +000095 /* Enable i2c clock */
Simon Glassedbf8b42014-10-01 19:57:24 -060096 ret = enable_i2c_clk(1, i2c_index);
97 if (ret)
98 goto err_clk;
99
Troy Kiskycc54a0f2012-07-19 08:18:25 +0000100 /* Make sure bus is idle */
Simon Glassedbf8b42014-10-01 19:57:24 -0600101 ret = force_idle_bus(p);
102 if (ret)
103 goto err_idle;
104
Peng Fan71204e92015-05-15 07:29:12 +0800105#ifndef CONFIG_DM_I2C
106 bus_i2c_init(i2c_index, speed, slave_addr, force_idle_bus, p);
107#endif
Simon Glassedbf8b42014-10-01 19:57:24 -0600108
109 return 0;
110
111err_idle:
112err_clk:
Simon Glassc6f3f322014-10-02 17:17:23 +0300113 gpio_free(p->scl.gp);
Marek Vasutcd3c5892014-12-16 14:09:16 +0100114err_req:
Simon Glassc6f3f322014-10-02 17:17:23 +0300115 gpio_free(p->sda.gp);
Simon Glassc6f3f322014-10-02 17:17:23 +0300116
Simon Glassedbf8b42014-10-01 19:57:24 -0600117 return ret;
Troy Kiskycc54a0f2012-07-19 08:18:25 +0000118}