/*
 * tegra20_das.c - Tegra20 DAS driver
 *
 * Author: Stephen Warren <swarren@nvidia.com>
 * Copyright (C) 2010 - NVIDIA, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 *
 * 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 <linux/device.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>
#include <sound/soc.h>
#include "tegra20_das.h"

#define DRV_NAME "tegra20-das"

static struct tegra20_das *das;

static inline void tegra20_das_write(u32 reg, u32 val)
{
	regmap_write(das->regmap, reg, val);
}

static inline u32 tegra20_das_read(u32 reg)
{
	u32 val;
	regmap_read(das->regmap, reg, &val);
	return val;
}

int tegra20_das_connect_dap_to_dac(int dap, int dac)
{
	u32 addr;
	u32 reg;

	if (!das)
		return -ENODEV;

	addr = TEGRA20_DAS_DAP_CTRL_SEL +
		(dap * TEGRA20_DAS_DAP_CTRL_SEL_STRIDE);
	reg = dac << TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P;

	tegra20_das_write(addr, reg);

	return 0;
}
EXPORT_SYMBOL_GPL(tegra20_das_connect_dap_to_dac);

int tegra20_das_connect_dap_to_dap(int dap, int otherdap, int master,
				   int sdata1rx, int sdata2rx)
{
	u32 addr;
	u32 reg;

	if (!das)
		return -ENODEV;

	addr = TEGRA20_DAS_DAP_CTRL_SEL +
		(dap * TEGRA20_DAS_DAP_CTRL_SEL_STRIDE);
	reg = otherdap << TEGRA20_DAS_DAP_CTRL_SEL_DAP_CTRL_SEL_P |
		!!sdata2rx << TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA2_TX_RX_P |
		!!sdata1rx << TEGRA20_DAS_DAP_CTRL_SEL_DAP_SDATA1_TX_RX_P |
		!!master << TEGRA20_DAS_DAP_CTRL_SEL_DAP_MS_SEL_P;

	tegra20_das_write(addr, reg);

	return 0;
}
EXPORT_SYMBOL_GPL(tegra20_das_connect_dap_to_dap);

int tegra20_das_connect_dac_to_dap(int dac, int dap)
{
	u32 addr;
	u32 reg;

	if (!das)
		return -ENODEV;

	addr = TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL +
		(dac * TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_STRIDE);
	reg = dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_CLK_SEL_P |
		dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA1_SEL_P |
		dap << TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL_DAC_SDATA2_SEL_P;

	tegra20_das_write(addr, reg);

	return 0;
}
EXPORT_SYMBOL_GPL(tegra20_das_connect_dac_to_dap);

#define LAST_REG(name) \
	(TEGRA20_DAS_##name + \
	 (TEGRA20_DAS_##name##_STRIDE * (TEGRA20_DAS_##name##_COUNT - 1)))

static bool tegra20_das_wr_rd_reg(struct device *dev, unsigned int reg)
{
	if ((reg >= TEGRA20_DAS_DAP_CTRL_SEL) &&
	    (reg <= LAST_REG(DAP_CTRL_SEL)))
		return true;
	if ((reg >= TEGRA20_DAS_DAC_INPUT_DATA_CLK_SEL) &&
	    (reg <= LAST_REG(DAC_INPUT_DATA_CLK_SEL)))
		return true;

	return false;
}

static const struct regmap_config tegra20_das_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.max_register = LAST_REG(DAC_INPUT_DATA_CLK_SEL),
	.writeable_reg = tegra20_das_wr_rd_reg,
	.readable_reg = tegra20_das_wr_rd_reg,
	.cache_type = REGCACHE_FLAT,
};

static int tegra20_das_probe(struct platform_device *pdev)
{
	struct resource *res, *region;
	void __iomem *regs;
	int ret = 0;

	if (das)
		return -ENODEV;

	das = devm_kzalloc(&pdev->dev, sizeof(struct tegra20_das), GFP_KERNEL);
	if (!das) {
		dev_err(&pdev->dev, "Can't allocate tegra20_das\n");
		ret = -ENOMEM;
		goto err;
	}
	das->dev = &pdev->dev;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "No memory resource\n");
		ret = -ENODEV;
		goto err;
	}

	region = devm_request_mem_region(&pdev->dev, res->start,
					 resource_size(res), pdev->name);
	if (!region) {
		dev_err(&pdev->dev, "Memory region already claimed\n");
		ret = -EBUSY;
		goto err;
	}

	regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
	if (!regs) {
		dev_err(&pdev->dev, "ioremap failed\n");
		ret = -ENOMEM;
		goto err;
	}

	das->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
					    &tegra20_das_regmap_config);
	if (IS_ERR(das->regmap)) {
		dev_err(&pdev->dev, "regmap init failed\n");
		ret = PTR_ERR(das->regmap);
		goto err;
	}

	ret = tegra20_das_connect_dap_to_dac(TEGRA20_DAS_DAP_ID_1,
					     TEGRA20_DAS_DAP_SEL_DAC1);
	if (ret) {
		dev_err(&pdev->dev, "Can't set up DAS DAP connection\n");
		goto err;
	}
	ret = tegra20_das_connect_dac_to_dap(TEGRA20_DAS_DAC_ID_1,
					     TEGRA20_DAS_DAC_SEL_DAP1);
	if (ret) {
		dev_err(&pdev->dev, "Can't set up DAS DAC connection\n");
		goto err;
	}

	ret = tegra20_das_connect_dap_to_dac(TEGRA20_DAS_DAP_ID_3,
					     TEGRA20_DAS_DAP_SEL_DAC3);
	if (ret) {
		dev_err(&pdev->dev, "Can't set up DAS DAP connection\n");
		goto err;
	}
	ret = tegra20_das_connect_dac_to_dap(TEGRA20_DAS_DAC_ID_3,
					     TEGRA20_DAS_DAC_SEL_DAP3);
	if (ret) {
		dev_err(&pdev->dev, "Can't set up DAS DAC connection\n");
		goto err;
	}

	platform_set_drvdata(pdev, das);

	return 0;

err:
	das = NULL;
	return ret;
}

static int tegra20_das_remove(struct platform_device *pdev)
{
	if (!das)
		return -ENODEV;

	das = NULL;

	return 0;
}

static const struct of_device_id tegra20_das_of_match[] = {
	{ .compatible = "nvidia,tegra20-das", },
	{},
};

static struct platform_driver tegra20_das_driver = {
	.probe = tegra20_das_probe,
	.remove = tegra20_das_remove,
	.driver = {
		.name = DRV_NAME,
		.of_match_table = tegra20_das_of_match,
	},
};
module_platform_driver(tegra20_das_driver);

MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
MODULE_DESCRIPTION("Tegra20 DAS driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
MODULE_DEVICE_TABLE(of, tegra20_das_of_match);