/*
 * arch/arm/mach-tegra/tegra3_tsensor.c
 *
 * Copyright (C) 2011 NVIDIA Corporation.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * 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.
 *
 */

#include <linux/kernel.h>
#include <linux/init.h>

#ifdef CONFIG_SENSORS_TEGRA_TSENSOR
#include <linux/io.h>
#include <linux/ioport.h>

#include <mach/iomap.h>
#include <mach/tsensor.h>
#include <mach/tegra_fuse.h>

#include "board.h"
#include "devices.h"
#include "fuse.h"

static struct tegra_tsensor_platform_data tsensor_data = {
	.hysteresis = 5,
	.sw_intr_temperature = 75,
	.hw_clk_div_temperature = 80,
	.hw_reset_temperature = 90,
};

/* fuse revision constants used for tsensor */
#define TSENSOR_FUSE_REVISION_DECIMAL 8
#define TSENSOR_FUSE_REVISION_INTEGER 0

/* scratch register offsets needed for powering off PMU */
#define SCRATCH54_OFFSET			0x258
#define SCRATCH55_OFFSET			0x25C

/* scratch 54 register bit field offsets */
#define PMU_OFF_DATA_OFFSET			8

/* scratch 55 register bit field offsets */
#define RESET_TEGRA_OFFSET			31
#define CONTROLLER_TYPE_OFFSET			30
#define I2C_CONTROLLER_ID_OFFSET		27
#define PINMUX_OFFSET				24
#define CHECKSUM_OFFSET				16
#define PMU_16BIT_SUPPORT_OFFSET		15
/* scratch 55 register bit field masks */
#define RESET_TEGRA_MASK			0x1
#define CONTROLLER_TYPE_MASK			0x1
#define I2C_CONTROLLER_ID_MASK			0x7
#define PINMUX_MASK				0x7
#define CHECKSUM_MASK				0xff
#define PMU_16BIT_SUPPORT_MASK			0x1


void __init tegra3_tsensor_init(struct tegra_tsensor_pmu_data *data)
{
	unsigned int reg, fuse_rev_integer, fuse_rev_decimal;
	int err;
	u32 val, checksum;
	void __iomem *pMem = NULL;
	/* tsensor driver is instantiated based on fuse revision */
	err = tegra_fuse_get_revision(&reg);
	if (err)
		goto errLabel;
	fuse_rev_decimal = (reg & 0xf);
	fuse_rev_integer = ((reg >> 4) & 0x7);
	pr_info("\nTegra3 fuse revision %d.%d \n", fuse_rev_integer,
		fuse_rev_decimal);
	if ((fuse_rev_decimal >= TSENSOR_FUSE_REVISION_DECIMAL) &&
		(fuse_rev_integer >= TSENSOR_FUSE_REVISION_INTEGER)) {

		if (!request_mem_region(TEGRA_PMC_BASE + SCRATCH54_OFFSET,
			8, "tegra-tsensor")) {
			pr_err(" [%s, line=%d]: Error mem busy\n",
				__func__, __LINE__);
		}

		pMem = ioremap(TEGRA_PMC_BASE + SCRATCH54_OFFSET, 8);
		if (!pMem) {
			pr_err(" [%s, line=%d]: can't ioremap "
				"pmc iomem\n", __FILE__, __LINE__);
		}

		/*
			Fill scratch registers to power off the device
			in case if temperature crosses threshold TH3
		*/
		val = (data->poweroff_reg_data << PMU_OFF_DATA_OFFSET) |
			data->poweroff_reg_addr;
		writel(val, pMem);

		val = ((data->reset_tegra & RESET_TEGRA_MASK) <<
				RESET_TEGRA_OFFSET) |
			((data->controller_type & CONTROLLER_TYPE_MASK) <<
				CONTROLLER_TYPE_OFFSET) |
			((data->i2c_controller_id & I2C_CONTROLLER_ID_MASK) <<
				I2C_CONTROLLER_ID_OFFSET) |
			((data->pinmux & PINMUX_MASK) << PINMUX_OFFSET) |
			((data->pmu_16bit_ops & PMU_16BIT_SUPPORT_MASK) <<
				PMU_16BIT_SUPPORT_OFFSET) |
			data->pmu_i2c_addr;

		checksum = data->poweroff_reg_addr +
			data->poweroff_reg_data + (val & 0xFF) +
			((val >> 8) & 0xFF) + ((val >> 24) & 0xFF);
		checksum &= 0xFF;
		checksum = 0x100 - checksum;

		val |= (checksum << CHECKSUM_OFFSET);
		writel(val, pMem + 4);

		/* set platform data for device before register */
		tegra_tsensor_device.dev.platform_data = &tsensor_data;
		platform_device_register(&tegra_tsensor_device);
	}
errLabel:
	return;
}

#else
void __init tegra3_tsensor_init(void) { }
#endif