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  • /*
     * (C) Copyright 2014 Freescale Semiconductor, Inc.
     * Author: Nitin Garg <nitin.garg@freescale.com>
     *             Ye Li <Ye.Li@freescale.com>
     *
     * SPDX-License-Identifier:	GPL-2.0+
     */
    
    #include <config.h>
    #include <common.h>
    #include <div64.h>
    #include <fuse.h>
    #include <asm/io.h>
    #include <asm/arch/clock.h>
    
    #include <asm/arch/sys_proto.h>
    
    #include <dm.h>
    #include <errno.h>
    #include <malloc.h>
    #include <thermal.h>
    #include <imx_thermal.h>
    
    
    /* board will busyloop until this many degrees C below CPU max temperature */
    #define TEMPERATURE_HOT_DELTA   5 /* CPU maxT - 5C */
    
    #define FACTOR0			10000000
    #define FACTOR1			15976
    #define FACTOR2			4297157
    #define MEASURE_FREQ		327
    
    #define TEMPERATURE_MIN         -40
    #define TEMPERATURE_HOT         85
    #define TEMPERATURE_MAX         125
    
    
    #define TEMPSENSE0_TEMP_CNT_SHIFT	8
    #define TEMPSENSE0_TEMP_CNT_MASK	(0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
    #define TEMPSENSE0_FINISHED		(1 << 2)
    #define TEMPSENSE0_MEASURE_TEMP		(1 << 1)
    #define TEMPSENSE0_POWER_DOWN		(1 << 0)
    #define MISC0_REFTOP_SELBIASOFF		(1 << 3)
    #define TEMPSENSE1_MEASURE_FREQ		0xffff
    
    
    struct thermal_data {
    	unsigned int fuse;
    
    #if defined(CONFIG_MX6)
    static int read_cpu_temperature(struct udevice *dev)
    
    {
    	int temperature;
    	unsigned int reg, n_meas;
    	const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
    	struct anatop_regs *anatop = (struct anatop_regs *)pdata->regs;
    
    	struct thermal_data *priv = dev_get_priv(dev);
    	u32 fuse = priv->fuse;
    
    	int t1, n1;
    	u32 c1, c2;
    	u64 temp64;
    
    	/*
    	 * Sensor data layout:
    	 *   [31:20] - sensor value @ 25C
    	 * We use universal formula now and only need sensor value @ 25C
    	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
    	 */
    	n1 = fuse >> 20;
    	t1 = 25; /* t1 always 25C */
    
    	/*
    	 * Derived from linear interpolation:
    	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
    	 * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
    	 * (Nmeas - n1) / (Tmeas - t1) = slope
    	 * We want to reduce this down to the minimum computation necessary
    	 * for each temperature read.  Also, we want Tmeas in millicelsius
    	 * and we don't want to lose precision from integer division. So...
    	 * Tmeas = (Nmeas - n1) / slope + t1
    	 * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
    	 * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
    	 * Let constant c1 = (-1000 / slope)
    	 * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
    	 * Let constant c2 = n1 *c1 + 1000 * t1
    	 * milli_Tmeas = c2 - Nmeas * c1
    	 */
    	temp64 = FACTOR0;
    	temp64 *= 1000;
    	do_div(temp64, FACTOR1 * n1 - FACTOR2);
    	c1 = temp64;
    	c2 = n1 * c1 + 1000 * t1;
    
    	/*
    	 * now we only use single measure, every time we read
    	 * the temperature, we will power on/down anadig thermal
    	 * module
    	 */
    	writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_clr);
    	writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_set);
    
    	/* setup measure freq */
    	reg = readl(&anatop->tempsense1);
    	reg &= ~TEMPSENSE1_MEASURE_FREQ;
    	reg |= MEASURE_FREQ;
    	writel(reg, &anatop->tempsense1);
    
    	/* start the measurement process */
    	writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_clr);
    	writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
    	writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_set);
    
    	/* make sure that the latest temp is valid */
    	while ((readl(&anatop->tempsense0) &
    		TEMPSENSE0_FINISHED) == 0)
    		udelay(10000);
    
    	/* read temperature count */
    	reg = readl(&anatop->tempsense0);
    	n_meas = (reg & TEMPSENSE0_TEMP_CNT_MASK)
    		>> TEMPSENSE0_TEMP_CNT_SHIFT;
    	writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
    
    	/* milli_Tmeas = c2 - Nmeas * c1 */
    
    	temperature = (long)(c2 - n_meas * c1)/1000;
    
    
    	/* power down anatop thermal sensor */
    	writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set);
    	writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_clr);
    
    	return temperature;
    }
    
    #elif defined(CONFIG_MX7)
    static int read_cpu_temperature(struct udevice *dev)
    {
    	unsigned int reg, tmp, start;
    	unsigned int raw_25c, te1;
    	int temperature;
    	unsigned int *priv = dev_get_priv(dev);
    	u32 fuse = *priv;
    	struct mxc_ccm_anatop_reg *ccm_anatop = (struct mxc_ccm_anatop_reg *)
    						 ANATOP_BASE_ADDR;
    	/*
    	 * fuse data layout:
    	 * [31:21] sensor value @ 25C
    	 * [20:18] hot temperature value
    	 * [17:9] sensor value of room
    	 * [8:0] sensor value of hot
    	 */
    
    	raw_25c = fuse >> 21;
    	if (raw_25c == 0)
    		raw_25c = 25;
    
    	te1 = (fuse >> 9) & 0x1ff;
    
    	/*
    	 * now we only use single measure, every time we read
    	 * the temperature, we will power on/down anadig thermal
    	 * module
    	 */
    	writel(TEMPMON_HW_ANADIG_TEMPSENSE1_POWER_DOWN_MASK, &ccm_anatop->tempsense1_clr);
    	writel(PMU_REF_REFTOP_SELFBIASOFF_MASK, &ccm_anatop->ref_set);
    
    	/* write measure freq */
    	reg = readl(&ccm_anatop->tempsense1);
    	reg &= ~TEMPMON_HW_ANADIG_TEMPSENSE1_MEASURE_FREQ_MASK;
    	reg |= TEMPMON_HW_ANADIG_TEMPSENSE1_MEASURE_FREQ(MEASURE_FREQ);
    	writel(reg, &ccm_anatop->tempsense1);
    
    	writel(TEMPMON_HW_ANADIG_TEMPSENSE1_MEASURE_TEMP_MASK, &ccm_anatop->tempsense1_clr);
    	writel(TEMPMON_HW_ANADIG_TEMPSENSE1_FINISHED_MASK, &ccm_anatop->tempsense1_clr);
    	writel(TEMPMON_HW_ANADIG_TEMPSENSE1_MEASURE_TEMP_MASK, &ccm_anatop->tempsense1_set);
    
    	start = get_timer(0);
    	/* Wait max 100ms */
    	do {
    		/*
    		 * Since we can not rely on finish bit, use 1ms delay to get
    		 * temperature. From RM, 17us is enough to get data, but
    		 * to gurantee to get the data, delay 100ms here.
    		 */
    		reg = readl(&ccm_anatop->tempsense1);
    		tmp = (reg & TEMPMON_HW_ANADIG_TEMPSENSE1_TEMP_VALUE_MASK)
    		       >> TEMPMON_HW_ANADIG_TEMPSENSE1_TEMP_VALUE_SHIFT;
    	} while (get_timer(0) < (start + 100));
    
    	writel(TEMPMON_HW_ANADIG_TEMPSENSE1_FINISHED_MASK, &ccm_anatop->tempsense1_clr);
    
    	/* power down anatop thermal sensor */
    	writel(TEMPMON_HW_ANADIG_TEMPSENSE1_POWER_DOWN_MASK, &ccm_anatop->tempsense1_set);
    	writel(PMU_REF_REFTOP_SELFBIASOFF_MASK, &ccm_anatop->ref_clr);
    
    	/* Single point */
    	temperature = tmp - (te1 - raw_25c);
    
    	return temperature;
    }
    #endif
    
    
    int imx_thermal_get_temp(struct udevice *dev, int *temp)
    {
    
    	struct thermal_data *priv = dev_get_priv(dev);
    
    	int cpu_tmp = 0;
    
    
    	cpu_tmp = read_cpu_temperature(dev);
    
    
    	while (cpu_tmp >= priv->critical) {
    		printf("CPU Temperature (%dC) too close to max (%dC)",
    		       cpu_tmp, priv->maxc);
    		puts(" waiting...\n");
    		udelay(5000000);
    
    		cpu_tmp = read_cpu_temperature(dev);
    
    	}
    
    	*temp = cpu_tmp;
    
    	return 0;
    }
    
    static const struct dm_thermal_ops imx_thermal_ops = {
    	.get_temp	= imx_thermal_get_temp,
    };
    
    static int imx_thermal_probe(struct udevice *dev)
    {
    	unsigned int fuse = ~0;
    
    	const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
    
    	struct thermal_data *priv = dev_get_priv(dev);
    
    
    	/* Read Temperature calibration data fuse */
    	fuse_read(pdata->fuse_bank, pdata->fuse_word, &fuse);
    
    
    	if (is_soc_type(MXC_SOC_MX6)) {
    		/* Check for valid fuse */
    		if (fuse == 0 || fuse == ~0) {
    
    			debug("CPU:   Thermal invalid data, fuse: 0x%x\n",
    
    	} else if (is_soc_type(MXC_SOC_MX7)) {
    		/* No Calibration data in FUSE? */
    		if ((fuse & 0x3ffff) == 0)
    			return -EPERM;
    		/* We do not support 105C TE2 */
    		if (((fuse & 0x1c0000) >> 18) == 0x6)
    			return -EPERM;
    
    	/* set critical cooling temp */
    
    	get_cpu_temp_grade(&priv->minc, &priv->maxc);
    
    	priv->critical = priv->maxc - TEMPERATURE_HOT_DELTA;
    
    
    	enable_thermal_clk();
    
    	return 0;
    }
    
    U_BOOT_DRIVER(imx_thermal) = {
    	.name	= "imx_thermal",
    	.id	= UCLASS_THERMAL,
    	.ops	= &imx_thermal_ops,
    	.probe	= imx_thermal_probe,
    
    	.priv_auto_alloc_size = sizeof(struct thermal_data),
    
    	.flags  = DM_FLAG_PRE_RELOC,
    };