1*552a848eSStefano Babic /*
2*552a848eSStefano Babic * Copyright (C) 2012 Boundary Devices Inc.
3*552a848eSStefano Babic *
4*552a848eSStefano Babic * SPDX-License-Identifier: GPL-2.0+
5*552a848eSStefano Babic */
6*552a848eSStefano Babic #include <common.h>
7*552a848eSStefano Babic #include <malloc.h>
8*552a848eSStefano Babic #include <asm/arch/clock.h>
9*552a848eSStefano Babic #include <asm/arch/imx-regs.h>
10*552a848eSStefano Babic #include <linux/errno.h>
11*552a848eSStefano Babic #include <asm/gpio.h>
12*552a848eSStefano Babic #include <asm/mach-imx/mxc_i2c.h>
13*552a848eSStefano Babic #include <watchdog.h>
14*552a848eSStefano Babic
force_idle_bus(void * priv)15*552a848eSStefano Babic int force_idle_bus(void *priv)
16*552a848eSStefano Babic {
17*552a848eSStefano Babic int i;
18*552a848eSStefano Babic int sda, scl;
19*552a848eSStefano Babic ulong elapsed, start_time;
20*552a848eSStefano Babic struct i2c_pads_info *p = (struct i2c_pads_info *)priv;
21*552a848eSStefano Babic int ret = 0;
22*552a848eSStefano Babic
23*552a848eSStefano Babic gpio_direction_input(p->sda.gp);
24*552a848eSStefano Babic gpio_direction_input(p->scl.gp);
25*552a848eSStefano Babic
26*552a848eSStefano Babic imx_iomux_v3_setup_pad(p->sda.gpio_mode);
27*552a848eSStefano Babic imx_iomux_v3_setup_pad(p->scl.gpio_mode);
28*552a848eSStefano Babic
29*552a848eSStefano Babic sda = gpio_get_value(p->sda.gp);
30*552a848eSStefano Babic scl = gpio_get_value(p->scl.gp);
31*552a848eSStefano Babic if ((sda & scl) == 1)
32*552a848eSStefano Babic goto exit; /* Bus is idle already */
33*552a848eSStefano Babic
34*552a848eSStefano Babic printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__,
35*552a848eSStefano Babic sda, scl, p->sda.gp, p->scl.gp);
36*552a848eSStefano Babic /* Send high and low on the SCL line */
37*552a848eSStefano Babic for (i = 0; i < 9; i++) {
38*552a848eSStefano Babic gpio_direction_output(p->scl.gp, 0);
39*552a848eSStefano Babic udelay(50);
40*552a848eSStefano Babic gpio_direction_input(p->scl.gp);
41*552a848eSStefano Babic udelay(50);
42*552a848eSStefano Babic }
43*552a848eSStefano Babic start_time = get_timer(0);
44*552a848eSStefano Babic for (;;) {
45*552a848eSStefano Babic sda = gpio_get_value(p->sda.gp);
46*552a848eSStefano Babic scl = gpio_get_value(p->scl.gp);
47*552a848eSStefano Babic if ((sda & scl) == 1)
48*552a848eSStefano Babic break;
49*552a848eSStefano Babic WATCHDOG_RESET();
50*552a848eSStefano Babic elapsed = get_timer(start_time);
51*552a848eSStefano Babic if (elapsed > (CONFIG_SYS_HZ / 5)) { /* .2 seconds */
52*552a848eSStefano Babic ret = -EBUSY;
53*552a848eSStefano Babic printf("%s: failed to clear bus, sda=%d scl=%d\n",
54*552a848eSStefano Babic __func__, sda, scl);
55*552a848eSStefano Babic break;
56*552a848eSStefano Babic }
57*552a848eSStefano Babic }
58*552a848eSStefano Babic exit:
59*552a848eSStefano Babic imx_iomux_v3_setup_pad(p->sda.i2c_mode);
60*552a848eSStefano Babic imx_iomux_v3_setup_pad(p->scl.i2c_mode);
61*552a848eSStefano Babic return ret;
62*552a848eSStefano Babic }
63*552a848eSStefano Babic
64*552a848eSStefano Babic static void * const i2c_bases[] = {
65*552a848eSStefano Babic (void *)I2C1_BASE_ADDR,
66*552a848eSStefano Babic (void *)I2C2_BASE_ADDR,
67*552a848eSStefano Babic #ifdef I2C3_BASE_ADDR
68*552a848eSStefano Babic (void *)I2C3_BASE_ADDR,
69*552a848eSStefano Babic #endif
70*552a848eSStefano Babic #ifdef I2C4_BASE_ADDR
71*552a848eSStefano Babic (void *)I2C4_BASE_ADDR,
72*552a848eSStefano Babic #endif
73*552a848eSStefano Babic };
74*552a848eSStefano Babic
75*552a848eSStefano Babic /* i2c_index can be from 0 - 3 */
setup_i2c(unsigned i2c_index,int speed,int slave_addr,struct i2c_pads_info * p)76*552a848eSStefano Babic int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
77*552a848eSStefano Babic struct i2c_pads_info *p)
78*552a848eSStefano Babic {
79*552a848eSStefano Babic char name[9];
80*552a848eSStefano Babic int ret;
81*552a848eSStefano Babic
82*552a848eSStefano Babic if (i2c_index >= ARRAY_SIZE(i2c_bases))
83*552a848eSStefano Babic return -EINVAL;
84*552a848eSStefano Babic
85*552a848eSStefano Babic snprintf(name, sizeof(name), "i2c_sda%01d", i2c_index);
86*552a848eSStefano Babic ret = gpio_request(p->sda.gp, name);
87*552a848eSStefano Babic if (ret)
88*552a848eSStefano Babic return ret;
89*552a848eSStefano Babic
90*552a848eSStefano Babic snprintf(name, sizeof(name), "i2c_scl%01d", i2c_index);
91*552a848eSStefano Babic ret = gpio_request(p->scl.gp, name);
92*552a848eSStefano Babic if (ret)
93*552a848eSStefano Babic goto err_req;
94*552a848eSStefano Babic
95*552a848eSStefano Babic /* Enable i2c clock */
96*552a848eSStefano Babic ret = enable_i2c_clk(1, i2c_index);
97*552a848eSStefano Babic if (ret)
98*552a848eSStefano Babic goto err_clk;
99*552a848eSStefano Babic
100*552a848eSStefano Babic /* Make sure bus is idle */
101*552a848eSStefano Babic ret = force_idle_bus(p);
102*552a848eSStefano Babic if (ret)
103*552a848eSStefano Babic goto err_idle;
104*552a848eSStefano Babic
105*552a848eSStefano Babic #ifndef CONFIG_DM_I2C
106*552a848eSStefano Babic bus_i2c_init(i2c_index, speed, slave_addr, force_idle_bus, p);
107*552a848eSStefano Babic #endif
108*552a848eSStefano Babic
109*552a848eSStefano Babic return 0;
110*552a848eSStefano Babic
111*552a848eSStefano Babic err_idle:
112*552a848eSStefano Babic err_clk:
113*552a848eSStefano Babic gpio_free(p->scl.gp);
114*552a848eSStefano Babic err_req:
115*552a848eSStefano Babic gpio_free(p->sda.gp);
116*552a848eSStefano Babic
117*552a848eSStefano Babic return ret;
118*552a848eSStefano Babic }
119