1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2012 Boundary Devices Inc.
4 */
5#include <common.h>
6#include <malloc.h>
7#include <asm/arch/clock.h>
8#include <asm/arch/imx-regs.h>
9#include <linux/delay.h>
10#include <linux/errno.h>
11#include <asm/gpio.h>
12#include <asm/mach-imx/mxc_i2c.h>
13#include <watchdog.h>
14
15int force_idle_bus(void *priv)
16{
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		schedule();
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
70#ifdef I2C4_BASE_ADDR
71	(void *)I2C4_BASE_ADDR,
72#endif
73#ifdef I2C5_BASE_ADDR
74	(void *)I2C5_BASE_ADDR,
75#endif
76#ifdef I2C6_BASE_ADDR
77	(void *)I2C6_BASE_ADDR,
78#endif
79};
80
81/* i2c_index can be from 0 - 3 */
82int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
83	      struct i2c_pads_info *p)
84{
85	char name[9];
86	int ret;
87
88	if (i2c_index >= ARRAY_SIZE(i2c_bases))
89		return -EINVAL;
90
91	snprintf(name, sizeof(name), "i2c_sda%01d", i2c_index);
92	ret = gpio_request(p->sda.gp, name);
93	if (ret)
94		return ret;
95
96	snprintf(name, sizeof(name), "i2c_scl%01d", i2c_index);
97	ret = gpio_request(p->scl.gp, name);
98	if (ret)
99		goto err_req;
100
101	/* Enable i2c clock */
102	ret = enable_i2c_clk(1, i2c_index);
103	if (ret)
104		goto err_clk;
105
106	/* Make sure bus is idle */
107	ret = force_idle_bus(p);
108	if (ret)
109		goto err_idle;
110
111#if !CONFIG_IS_ENABLED(DM_I2C)
112	bus_i2c_init(i2c_index, speed, slave_addr, force_idle_bus, p);
113#endif
114
115	return 0;
116
117err_idle:
118err_clk:
119	gpio_free(p->scl.gp);
120err_req:
121	gpio_free(p->sda.gp);
122
123	return ret;
124}
125