/*
   * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   *      http://www.samsung.com
   * Akshay Saraswat <akshay.s@samsung.com>
   *
   * EXYNOS - Thermal Management Unit
   *
   * See file CREDITS for list of people who contributed to this
   * project.
   *
   * 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.
   * 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., 59 Temple Place, Suite 330, Boston,
   * MA 02111-1307 USA
   */
  
  #include <common.h>
  #include <errno.h>
  #include <fdtdec.h>
  #include <tmu.h>
  #include <asm/arch/tmu.h>
  #include <asm/arch/power.h>
  
  #define TRIMINFO_RELOAD		1
  #define CORE_EN			1
  #define THERM_TRIP_EN		(1 << 12)
  
  #define INTEN_RISE0		1
  #define INTEN_RISE1		(1 << 4)
  #define INTEN_RISE2		(1 << 8)
  #define INTEN_FALL0		(1 << 16)
  #define INTEN_FALL1		(1 << 20)
  #define INTEN_FALL2		(1 << 24)
  
  #define TRIM_INFO_MASK		0xff
  
  #define INTCLEAR_RISE0		1
  #define INTCLEAR_RISE1		(1 << 4)
  #define INTCLEAR_RISE2		(1 << 8)
  #define INTCLEAR_FALL0		(1 << 16)
  #define INTCLEAR_FALL1		(1 << 20)
  #define INTCLEAR_FALL2		(1 << 24)
  #define INTCLEARALL		(INTCLEAR_RISE0 | INTCLEAR_RISE1 | \
  				 INTCLEAR_RISE2 | INTCLEAR_FALL0 | \
  				 INTCLEAR_FALL1 | INTCLEAR_FALL2)
  
  /* Tmeperature threshold values for various thermal events */
  struct temperature_params {
  	/* minimum value in temperature code range */
  	unsigned min_val;
  	/* maximum value in temperature code range */
  	unsigned max_val;
  	/* temperature threshold to start warning */
  	unsigned start_warning;
  	/* temperature threshold CPU tripping */
  	unsigned start_tripping;
  	/* temperature threshold for HW tripping */
  	unsigned hardware_tripping;
  };
  
  /* Pre-defined values and thresholds for calibration of current temperature */
  struct tmu_data {
  	/* pre-defined temperature thresholds */
  	struct temperature_params ts;
  	/* pre-defined efuse range minimum value */
  	unsigned efuse_min_value;
  	/* pre-defined efuse value for temperature calibration */
  	unsigned efuse_value;
  	/* pre-defined efuse range maximum value */
  	unsigned efuse_max_value;
  	/* current temperature sensing slope */
  	unsigned slope;
  };
  
  /* TMU device specific details and status */
  struct tmu_info {
  	/* base Address for the TMU */
  	struct exynos5_tmu_reg *tmu_base;
  	/* mux Address for the TMU */
  	int tmu_mux;
  	/* pre-defined values for calibration and thresholds */
  	struct tmu_data data;
  	/* value required for triminfo_25 calibration */
  	unsigned te1;
  	/* value required for triminfo_85 calibration */
  	unsigned te2;
  	/* Value for measured data calibration */
  	int dc_value;
  	/* enum value indicating status of the TMU */
  	int tmu_state;
  };
  
  /* Global struct tmu_info variable to store init values */
  static struct tmu_info gbl_info;
  
  /*
   * Get current temperature code from register,
   * then calculate and calibrate it's value
   * in degree celsius.
   *
   * @return	current temperature of the chip as sensed by TMU
   */
  static int get_cur_temp(struct tmu_info *info)
  {
  	struct exynos5_tmu_reg *reg = info->tmu_base;
  	ulong start;
  	int cur_temp = 0;
  
  	/*
  	 * Temperature code range between min 25 and max 125.
  	 * May run more than once for first call as initial sensing
  	 * has not yet happened.
  	 */
  	if (info->tmu_state == TMU_STATUS_NORMAL) {
  		start = get_timer(0);
  		do {
  			cur_temp = readl(&reg->current_temp) & 0xff;
  		} while ((cur_temp == 0) || (get_timer(start) > 100));
  	}
  
  	if (cur_temp == 0)
  		return cur_temp;
  
  	/* Calibrate current temperature */
  	cur_temp = cur_temp - info->te1 + info->dc_value;
  
  	return cur_temp;
  }
  
  /*
   * Monitors status of the TMU device and exynos temperature
   *
   * @param temp	pointer to the current temperature value
   * @return	enum tmu_status_t value, code indicating event to execute
   */
  enum tmu_status_t tmu_monitor(int *temp)
  {
  	int cur_temp;
  	struct tmu_data *data = &gbl_info.data;
  
  	if (gbl_info.tmu_state == TMU_STATUS_INIT)
  		return TMU_STATUS_INIT;
  
  	/* Read current temperature of the SOC */
  	cur_temp = get_cur_temp(&gbl_info);
  
  	if (!cur_temp)
  		goto out;
  
  	*temp = cur_temp;
  
  	/* Temperature code lies between min 25 and max 125 */
  	if ((cur_temp >= data->ts.start_tripping) &&
  	    (cur_temp <= data->ts.max_val))
  		return TMU_STATUS_TRIPPED;
  
  	if (cur_temp >= data->ts.start_warning)
  		return TMU_STATUS_WARNING;
  
  	if ((cur_temp < data->ts.start_warning) &&
  	    (cur_temp >= data->ts.min_val))
  		return TMU_STATUS_NORMAL;
  
   out:
  	/* Temperature code does not lie between min 25 and max 125 */
  	gbl_info.tmu_state = TMU_STATUS_INIT;
  	debug("EXYNOS_TMU: Thermal reading failed
  ");
  	return TMU_STATUS_INIT;
  }
  
  /*
   * Get TMU specific pre-defined values from FDT
   *
   * @param info	pointer to the tmu_info struct
   * @param blob  FDT blob
   * @return	int value, 0 for success
   */
  static int get_tmu_fdt_values(struct tmu_info *info, const void *blob)
  {
  #ifdef CONFIG_OF_CONTROL
  	fdt_addr_t addr;
  	int node;
  	int error = 0;
  
  	/* Get the node from FDT for TMU */
  	node = fdtdec_next_compatible(blob, 0,
  				      COMPAT_SAMSUNG_EXYNOS_TMU);
  	if (node < 0) {
  		debug("EXYNOS_TMU: No node for tmu in device tree
  ");
  		return -1;
  	}
  
  	/*
  	 * Get the pre-defined TMU specific values from FDT.
  	 * All of these are expected to be correct otherwise
  	 * miscalculation of register values in tmu_setup_parameters
  	 * may result in misleading current temperature.
  	 */
  	addr = fdtdec_get_addr(blob, node, "reg");
  	if (addr == FDT_ADDR_T_NONE) {
  		debug("%s: Missing tmu-base
  ", __func__);
  		return -1;
  	}
  	info->tmu_base = (struct exynos5_tmu_reg *)addr;
  
  	/* Optional field. */
  	info->tmu_mux = fdtdec_get_int(blob,
  				node, "samsung,mux", -1);
  	/* Take default value as per the user manual b(110) */
  	if (info->tmu_mux == -1)
  		info->tmu_mux = 0x6;
  
  	info->data.ts.min_val = fdtdec_get_int(blob,
  				node, "samsung,min-temp", -1);
  	error |= (info->data.ts.min_val == -1);
  	info->data.ts.max_val = fdtdec_get_int(blob,
  				node, "samsung,max-temp", -1);
  	error |= (info->data.ts.max_val == -1);
  	info->data.ts.start_warning = fdtdec_get_int(blob,
  				node, "samsung,start-warning", -1);
  	error |= (info->data.ts.start_warning == -1);
  	info->data.ts.start_tripping = fdtdec_get_int(blob,
  				node, "samsung,start-tripping", -1);
  	error |= (info->data.ts.start_tripping == -1);
  	info->data.ts.hardware_tripping = fdtdec_get_int(blob,
  				node, "samsung,hw-tripping", -1);
  	error |= (info->data.ts.hardware_tripping == -1);
  	info->data.efuse_min_value = fdtdec_get_int(blob,
  				node, "samsung,efuse-min-value", -1);
  	error |= (info->data.efuse_min_value == -1);
  	info->data.efuse_value = fdtdec_get_int(blob,
  				node, "samsung,efuse-value", -1);
  	error |= (info->data.efuse_value == -1);
  	info->data.efuse_max_value = fdtdec_get_int(blob,
  				node, "samsung,efuse-max-value", -1);
  	error |= (info->data.efuse_max_value == -1);
  	info->data.slope = fdtdec_get_int(blob,
  				node, "samsung,slope", -1);
  	error |= (info->data.slope == -1);
  	info->dc_value = fdtdec_get_int(blob,
  				node, "samsung,dc-value", -1);
  	error |= (info->dc_value == -1);
  
  	if (error) {
  		debug("fail to get tmu node properties
  ");
  		return -1;
  	}
  #else
  	/* Non DT support may never be added. Just in case  */
  	return -1;
  #endif
  
  	return 0;
  }
  
  /*
   * Calibrate and calculate threshold values and
   * enable interrupt levels
   *
   * @param	info pointer to the tmu_info struct
   */
  static void tmu_setup_parameters(struct tmu_info *info)
  {
  	unsigned te_code, con;
  	unsigned warning_code, trip_code, hwtrip_code;
  	unsigned cooling_temp;
  	unsigned rising_value;
  	struct tmu_data *data = &info->data;
  	struct exynos5_tmu_reg *reg = info->tmu_base;
  
  	/* Must reload for reading efuse value from triminfo register */
  	writel(TRIMINFO_RELOAD, &reg->triminfo_control);
  
  	/* Get the compensation parameter */
  	te_code = readl(&reg->triminfo);
  	info->te1 = te_code & TRIM_INFO_MASK;
  	info->te2 = ((te_code >> 8) & TRIM_INFO_MASK);
  
  	if ((data->efuse_min_value > info->te1) ||
  			(info->te1 > data->efuse_max_value)
  			||  (info->te2 != 0))
  		info->te1 = data->efuse_value;
  
  	/* Get RISING & FALLING Threshold value */
  	warning_code = data->ts.start_warning
  			+ info->te1 - info->dc_value;
  	trip_code = data->ts.start_tripping
  			+ info->te1 - info->dc_value;
  	hwtrip_code = data->ts.hardware_tripping
  			+ info->te1 - info->dc_value;
  
  	cooling_temp = 0;
  
  	rising_value = ((warning_code << 8) |
  			(trip_code << 16) |
  			(hwtrip_code << 24));
  
  	/* Set interrupt level */
  	writel(rising_value, &reg->threshold_temp_rise);
  	writel(cooling_temp, &reg->threshold_temp_fall);
  
  	/*
  	 * Init TMU control tuning parameters
  	 * [28:24] VREF - Voltage reference
  	 * [15:13] THERM_TRIP_MODE - Tripping mode
  	 * [12] THERM_TRIP_EN - Thermal tripping enable
  	 * [11:8] BUF_SLOPE_SEL - Gain of amplifier
  	 * [6] THERM_TRIP_BY_TQ_EN - Tripping by TQ pin
  	 */
  	writel(data->slope, &reg->tmu_control);
  
  	writel(INTCLEARALL, &reg->intclear);
  
  	/* TMU core enable */
  	con = readl(&reg->tmu_control);
  	con |= THERM_TRIP_EN | CORE_EN | (info->tmu_mux << 20);
  
  	writel(con, &reg->tmu_control);
  
  	/* Enable HW thermal trip */
  	set_hw_thermal_trip();
  
  	/* LEV1 LEV2 interrupt enable */
  	writel(INTEN_RISE1 | INTEN_RISE2, &reg->inten);
  }
  
  /*
   * Initialize TMU device
   *
   * @param blob  FDT blob
   * @return	int value, 0 for success
   */
  int tmu_init(const void *blob)
  {
  	gbl_info.tmu_state = TMU_STATUS_INIT;
  	if (get_tmu_fdt_values(&gbl_info, blob) < 0)
  		goto ret;
  
  	tmu_setup_parameters(&gbl_info);
  	gbl_info.tmu_state = TMU_STATUS_NORMAL;
  ret:
  	return gbl_info.tmu_state;
  }