[people/ms/u-boot.git] / arch / arm / imx-common / i2c-mxv7.c

/*
 * Copyright (C) 2012 Boundary Devices Inc.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */
#include <common.h>
#include <malloc.h>
#include <asm/arch/clock.h>
#include <asm/arch/imx-regs.h>
#include <linux/errno.h>
#include <asm/gpio.h>
#include <asm/imx-common/mxc_i2c.h>
#include <watchdog.h>

int force_idle_bus(void *priv)
{
	int i;
	int sda, scl;
	ulong elapsed, start_time;
	struct i2c_pads_info *p = (struct i2c_pads_info *)priv;
	int ret = 0;

	gpio_direction_input(p->sda.gp);
	gpio_direction_input(p->scl.gp);

	imx_iomux_v3_setup_pad(p->sda.gpio_mode);
	imx_iomux_v3_setup_pad(p->scl.gpio_mode);

	sda = gpio_get_value(p->sda.gp);
	scl = gpio_get_value(p->scl.gp);
	if ((sda & scl) == 1)
		goto exit;		/* Bus is idle already */

	printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__,
		sda, scl, p->sda.gp, p->scl.gp);
	/* Send high and low on the SCL line */
	for (i = 0; i < 9; i++) {
		gpio_direction_output(p->scl.gp, 0);
		udelay(50);
		gpio_direction_input(p->scl.gp);
		udelay(50);
	}
	start_time = get_timer(0);
	for (;;) {
		sda = gpio_get_value(p->sda.gp);
		scl = gpio_get_value(p->scl.gp);
		if ((sda & scl) == 1)
			break;
		WATCHDOG_RESET();
		elapsed = get_timer(start_time);
		if (elapsed > (CONFIG_SYS_HZ / 5)) {	/* .2 seconds */
			ret = -EBUSY;
			printf("%s: failed to clear bus, sda=%d scl=%d\n",
					__func__, sda, scl);
			break;
		}
	}
exit:
	imx_iomux_v3_setup_pad(p->sda.i2c_mode);
	imx_iomux_v3_setup_pad(p->scl.i2c_mode);
	return ret;
}

static void * const i2c_bases[] = {
	(void *)I2C1_BASE_ADDR,
	(void *)I2C2_BASE_ADDR,
#ifdef I2C3_BASE_ADDR
	(void *)I2C3_BASE_ADDR,
#endif
#ifdef I2C4_BASE_ADDR
	(void *)I2C4_BASE_ADDR,
#endif
};

/* i2c_index can be from 0 - 3 */
int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
	      struct i2c_pads_info *p)
{
	char name[9];
	int ret;

	if (i2c_index >= ARRAY_SIZE(i2c_bases))
		return -EINVAL;

	snprintf(name, sizeof(name), "i2c_sda%01d", i2c_index);
	ret = gpio_request(p->sda.gp, name);
	if (ret)
		return ret;

	snprintf(name, sizeof(name), "i2c_scl%01d", i2c_index);
	ret = gpio_request(p->scl.gp, name);
	if (ret)
		goto err_req;

	/* Enable i2c clock */
	ret = enable_i2c_clk(1, i2c_index);
	if (ret)
		goto err_clk;

	/* Make sure bus is idle */
	ret = force_idle_bus(p);
	if (ret)
		goto err_idle;

#ifndef CONFIG_DM_I2C
	bus_i2c_init(i2c_index, speed, slave_addr, force_idle_bus, p);
#endif

	return 0;

err_idle:
err_clk:
	gpio_free(p->scl.gp);
err_req:
	gpio_free(p->sda.gp);

	return ret;
}
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	*/
cc54a0f7 TK	6	#include <common.h>
c6f3f323	7	#include <malloc.h>
cc54a0f7 TK	8	#include <asm/arch/clock.h>
cc54a0f7 TK	9	#include <asm/arch/imx-regs.h>
1221ce45	10	#include <linux/errno.h>
cc54a0f7 TK	11	#include <asm/gpio.h>
	12	#include <asm/imx-common/mxc_i2c.h>
	13	#include <watchdog.h>
	14
71204e95	15	int force_idle_bus(void *priv)
cc54a0f7 TK	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	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	}
	58	exit:
	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
	64	static 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
21a26940 HS	70	#ifdef I2C4_BASE_ADDR
	71	(void *)I2C4_BASE_ADDR,
	72	#endif
cc54a0f7 TK	73	};
cc54a0f7 TK	74
21a26940	75	/* i2c_index can be from 0 - 3 */
edbf8b4f SG	76	int setup_i2c(unsigned i2c_index, int speed, int slave_addr,
edbf8b4f SG	77	struct i2c_pads_info *p)
cc54a0f7	78	{
cd3c5896	79	char name[9];
edbf8b4f SG	80	int ret;
edbf8b4f SG	81
cc54a0f7	82	if (i2c_index >= ARRAY_SIZE(i2c_bases))
edbf8b4f	83	return -EINVAL;
c6f3f323	84
cd3c5896 MV	85	snprintf(name, sizeof(name), "i2c_sda%01d", i2c_index);
cd3c5896 MV	86	ret = gpio_request(p->sda.gp, name);
c6f3f323	87	if (ret)
cd3c5896	88	return ret;
c6f3f323	89
cd3c5896 MV	90	snprintf(name, sizeof(name), "i2c_scl%01d", i2c_index);
cd3c5896 MV	91	ret = gpio_request(p->scl.gp, name);
c6f3f323	92	if (ret)
cd3c5896	93	goto err_req;
c6f3f323	94
cc54a0f7	95	/* Enable i2c clock */
edbf8b4f SG	96	ret = enable_i2c_clk(1, i2c_index);
	97	if (ret)
	98	goto err_clk;
	99
cc54a0f7	100	/* Make sure bus is idle */
edbf8b4f SG	101	ret = force_idle_bus(p);
	102	if (ret)
	103	goto err_idle;
	104
71204e95 PF	105	#ifndef CONFIG_DM_I2C
	106	bus_i2c_init(i2c_index, speed, slave_addr, force_idle_bus, p);
	107	#endif
edbf8b4f SG	108
	109	return 0;
	110
	111	err_idle:
	112	err_clk:
c6f3f323	113	gpio_free(p->scl.gp);
cd3c5896	114	err_req:
c6f3f323	115	gpio_free(p->sda.gp);
c6f3f323	116
edbf8b4f	117	return ret;
cc54a0f7	118	}