src/soc/rockchip/rk3288/software_i2c.c

/*
 * This file is part of the coreboot project.
 *
 * Copyright 2015 Google, Inc.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301 USA
 */

#include <arch/io.h>
#include <console/console.h>
#include <device/i2c.h>
#include <gpio.h>
#include <soc/grf.h>
#include <soc/i2c.h>
#include <soc/pmu.h>

static struct {
	gpio_t scl;
	gpio_t sda;
} pins[] = {
	[0]{.scl = GPIO(0, C, 0), .sda = GPIO(0, B, 7)},
	[1]{.scl = GPIO(8, A, 5), .sda = GPIO(8, A, 4)},
	[2]{.scl = GPIO(6, B, 2), .sda = GPIO(6, B, 1)},
	[3]{.scl = GPIO(2, C, 0), .sda = GPIO(2, C, 1)},
	[4]{.scl = GPIO(7, C, 2), .sda = GPIO(7, C, 1)},
	[5]{.scl = GPIO(7, C, 4), .sda = GPIO(7, C, 3)},
};

static int get_scl(unsigned bus)
{
	return gpio_get(pins[bus].scl);
}

static int get_sda(unsigned bus)
{
	return gpio_get(pins[bus].sda);
}

static void set_scl(unsigned bus, int high)
{
	if (high)
		gpio_input_pullup(pins[bus].scl);
	else
		gpio_output(pins[bus].scl, 0);
}

static void set_sda(unsigned bus, int high)
{
	if (high)
		gpio_input_pullup(pins[bus].sda);
	else
		gpio_output(pins[bus].sda, 0);
}

static struct software_i2c_ops rk_ops = {
	.get_scl = get_scl,
	.get_sda = get_sda,
	.set_scl = set_scl,
	.set_sda = set_sda,
};

void software_i2c_attach(unsigned bus)
{
	software_i2c[bus] = &rk_ops;

	/* Mux pins to GPIO function for software I2C emulation. */
	switch (bus) {
	case 0:
		clrbits_le32(&rk3288_pmu->iomux_i2c0scl, IOMUX_I2C0SCL);
		clrbits_le32(&rk3288_pmu->iomux_i2c0sda, IOMUX_I2C0SDA);
		break;
	case 1:
		writel(IOMUX_GPIO(IOMUX_I2C1), &rk3288_grf->iomux_i2c1);
		break;
	case 2:
		writel(IOMUX_GPIO(IOMUX_I2C2), &rk3288_grf->iomux_i2c2);
		break;
	case 3:
		writel(IOMUX_GPIO(IOMUX_I2C3), &rk3288_grf->iomux_i2c3);
		break;
	case 4:
		writel(IOMUX_GPIO(IOMUX_I2C4), &rk3288_grf->iomux_i2c4);
		break;
	case 5:
		writel(IOMUX_GPIO(IOMUX_I2C5SCL), &rk3288_grf->iomux_i2c5scl);
		writel(IOMUX_GPIO(IOMUX_I2C5SDA), &rk3288_grf->iomux_i2c5sda);
		break;
	default:
		die("Unknown I2C bus number!");
	}

	/* Initialize bus to idle state. */
	set_scl(bus, 1);
	set_sda(bus, 1);
}

void software_i2c_detach(unsigned bus)
{
	software_i2c[bus] = NULL;

	/* Mux pins back to hardware I2C controller. */
	switch (bus) {
	case 0:
		setbits_le32(&rk3288_pmu->iomux_i2c0scl, IOMUX_I2C0SCL);
		setbits_le32(&rk3288_pmu->iomux_i2c0sda, IOMUX_I2C0SDA);
		break;
	case 1:
		writel(IOMUX_I2C1, &rk3288_grf->iomux_i2c1);
		break;
	case 2:
		writel(IOMUX_I2C2, &rk3288_grf->iomux_i2c2);
		break;
	case 3:
		writel(IOMUX_I2C3, &rk3288_grf->iomux_i2c3);
		break;
	case 4:
		writel(IOMUX_I2C4, &rk3288_grf->iomux_i2c4);
		break;
	case 5:
		writel(IOMUX_I2C5SCL, &rk3288_grf->iomux_i2c5scl);
		writel(IOMUX_I2C5SDA, &rk3288_grf->iomux_i2c5sda);
		break;
	default:
		die("Unknown I2C bus number!");
	}
}