1 /* 2 * (C) Copyright 2014 Freescale Semiconductor, Inc. 3 * Author: Nitin Garg <nitin.garg@freescale.com> 4 * Ye Li <Ye.Li@freescale.com> 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #include <config.h> 10 #include <common.h> 11 #include <div64.h> 12 #include <fuse.h> 13 #include <asm/io.h> 14 #include <asm/arch/clock.h> 15 #include <asm/arch/sys_proto.h> 16 #include <dm.h> 17 #include <errno.h> 18 #include <malloc.h> 19 #include <thermal.h> 20 #include <imx_thermal.h> 21 22 #define FACTOR0 10000000 23 #define FACTOR1 15976 24 #define FACTOR2 4297157 25 #define MEASURE_FREQ 327 26 27 #define TEMPSENSE0_TEMP_CNT_SHIFT 8 28 #define TEMPSENSE0_TEMP_CNT_MASK (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT) 29 #define TEMPSENSE0_FINISHED (1 << 2) 30 #define TEMPSENSE0_MEASURE_TEMP (1 << 1) 31 #define TEMPSENSE0_POWER_DOWN (1 << 0) 32 #define MISC0_REFTOP_SELBIASOFF (1 << 3) 33 #define TEMPSENSE1_MEASURE_FREQ 0xffff 34 35 struct thermal_data { 36 unsigned int fuse; 37 int passive; 38 int minc; 39 int maxc; 40 }; 41 42 static int read_cpu_temperature(struct udevice *dev) 43 { 44 int temperature; 45 unsigned int reg, n_meas; 46 const struct imx_thermal_plat *pdata = dev_get_platdata(dev); 47 struct anatop_regs *anatop = (struct anatop_regs *)pdata->regs; 48 struct thermal_data *priv = dev_get_priv(dev); 49 u32 fuse = priv->fuse; 50 int t1, n1; 51 u32 c1, c2; 52 u64 temp64; 53 54 /* 55 * Sensor data layout: 56 * [31:20] - sensor value @ 25C 57 * We use universal formula now and only need sensor value @ 25C 58 * slope = 0.4297157 - (0.0015976 * 25C fuse) 59 */ 60 n1 = fuse >> 20; 61 t1 = 25; /* t1 always 25C */ 62 63 /* 64 * Derived from linear interpolation: 65 * slope = 0.4297157 - (0.0015976 * 25C fuse) 66 * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0 67 * (Nmeas - n1) / (Tmeas - t1) = slope 68 * We want to reduce this down to the minimum computation necessary 69 * for each temperature read. Also, we want Tmeas in millicelsius 70 * and we don't want to lose precision from integer division. So... 71 * Tmeas = (Nmeas - n1) / slope + t1 72 * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1 73 * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1 74 * Let constant c1 = (-1000 / slope) 75 * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1 76 * Let constant c2 = n1 *c1 + 1000 * t1 77 * milli_Tmeas = c2 - Nmeas * c1 78 */ 79 temp64 = FACTOR0; 80 temp64 *= 1000; 81 do_div(temp64, FACTOR1 * n1 - FACTOR2); 82 c1 = temp64; 83 c2 = n1 * c1 + 1000 * t1; 84 85 /* 86 * now we only use single measure, every time we read 87 * the temperature, we will power on/down anadig thermal 88 * module 89 */ 90 writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_clr); 91 writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_set); 92 93 /* setup measure freq */ 94 reg = readl(&anatop->tempsense1); 95 reg &= ~TEMPSENSE1_MEASURE_FREQ; 96 reg |= MEASURE_FREQ; 97 writel(reg, &anatop->tempsense1); 98 99 /* start the measurement process */ 100 writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_clr); 101 writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr); 102 writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_set); 103 104 /* make sure that the latest temp is valid */ 105 while ((readl(&anatop->tempsense0) & 106 TEMPSENSE0_FINISHED) == 0) 107 udelay(10000); 108 109 /* read temperature count */ 110 reg = readl(&anatop->tempsense0); 111 n_meas = (reg & TEMPSENSE0_TEMP_CNT_MASK) 112 >> TEMPSENSE0_TEMP_CNT_SHIFT; 113 writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr); 114 115 /* milli_Tmeas = c2 - Nmeas * c1 */ 116 temperature = (c2 - n_meas * c1)/1000; 117 118 /* power down anatop thermal sensor */ 119 writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set); 120 writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_clr); 121 122 return temperature; 123 } 124 125 int imx_thermal_get_temp(struct udevice *dev, int *temp) 126 { 127 struct thermal_data *priv = dev_get_priv(dev); 128 int cpu_tmp = 0; 129 130 cpu_tmp = read_cpu_temperature(dev); 131 while (cpu_tmp > priv->minc && cpu_tmp < priv->maxc) { 132 if (cpu_tmp >= priv->passive) { 133 printf("CPU Temperature is %d C, too hot to boot, waiting...\n", 134 cpu_tmp); 135 udelay(5000000); 136 cpu_tmp = read_cpu_temperature(dev); 137 } else { 138 break; 139 } 140 } 141 142 *temp = cpu_tmp; 143 144 return 0; 145 } 146 147 static const struct dm_thermal_ops imx_thermal_ops = { 148 .get_temp = imx_thermal_get_temp, 149 }; 150 151 static int imx_thermal_probe(struct udevice *dev) 152 { 153 unsigned int fuse = ~0; 154 155 const struct imx_thermal_plat *pdata = dev_get_platdata(dev); 156 struct thermal_data *priv = dev_get_priv(dev); 157 158 /* Read Temperature calibration data fuse */ 159 fuse_read(pdata->fuse_bank, pdata->fuse_word, &fuse); 160 161 /* Check for valid fuse */ 162 if (fuse == 0 || fuse == ~0) { 163 printf("CPU: Thermal invalid data, fuse: 0x%x\n", fuse); 164 return -EPERM; 165 } 166 167 /* set passive cooling temp to max - 20C */ 168 get_cpu_temp_grade(&priv->minc, &priv->maxc); 169 priv->passive = priv->maxc - 20; 170 priv->fuse = fuse; 171 172 enable_thermal_clk(); 173 174 return 0; 175 } 176 177 U_BOOT_DRIVER(imx_thermal) = { 178 .name = "imx_thermal", 179 .id = UCLASS_THERMAL, 180 .ops = &imx_thermal_ops, 181 .probe = imx_thermal_probe, 182 .priv_auto_alloc_size = sizeof(struct thermal_data), 183 .flags = DM_FLAG_PRE_RELOC, 184 }; 185