#include <linux/module.h>
#include <linux/io.h>		// readl_relaxed, writel_relaxed
#include <linux/cpu_cooling.h>

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Tango CPU throttling");

/*** CPU TEMPERATURE SENSOR ***/
#define SENSOR_ADDR 0x920100
static void __iomem *sensor_base;

#define TEMPSI_CMD	sensor_base + 0
#define TEMPSI_RES	sensor_base + 4
#define TEMPSI_CFG	sensor_base + 8

static const u8 temperature[] = {
	46, 51, 55, 60, 64, 69, 74, 79, 83, 88, 93, 97, 101, 106, 110, 115, 120, 124, 129, 133, 137,
};

static int tango_get_temp(struct thermal_zone_device *tz, unsigned long *res)
{
	int i;

	for (i = 20; i < 40; ++i)
	{
		writel_relaxed(i << 8 | 2, TEMPSI_CMD);
		while ((readl_relaxed(TEMPSI_CMD) & 0x80) == 0);
		if (readl_relaxed(TEMPSI_RES) == 0) break;
	}

	*res = temperature[i-20] * 1000;
	return 0;
}

static int tango_bind(struct thermal_zone_device *tz, struct thermal_cooling_device *cdev)
{
	return thermal_zone_bind_cooling_device(tz, 0, cdev, 4, 1);
}

static int tango_get_trip_type(struct thermal_zone_device *tz, int idx, enum thermal_trip_type *res)
{
	if (idx != 0) return -EINVAL;
	*res = THERMAL_TRIP_PASSIVE;
	return 0;
}

static int tango_get_trip_temp(struct thermal_zone_device *tz, int idx, unsigned long *res)
{
	if (idx != 0) return -EINVAL;
	*res = 70000;
	return 0;
}

static struct thermal_zone_device_ops ops = {
	.bind		= tango_bind,
	.get_temp	= tango_get_temp,
	.get_mode = 0,
	.get_trip_type	= tango_get_trip_type,
	.get_trip_temp	= tango_get_trip_temp,
};

static struct thermal_cooling_device *cdev;
static struct thermal_zone_device *tzdev;

static int ts_init(void)
{
	sensor_base = ioremap(SENSOR_ADDR, 16);
	writel_relaxed( 1, TEMPSI_CMD);
	writel_relaxed(50, TEMPSI_CFG);
	cdev = cpufreq_cooling_register(cpu_present_mask);
	tzdev = thermal_zone_device_register("tango_tz", 1, 0, NULL, &ops, NULL, 5000, 13000);
	return 0;
}

static void __exit ts_cleanup(void) { return; }

module_init(ts_init);
module_exit(ts_cleanup);