1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * TI Bandgap temperature sensor driver for K3 SoC Family 4 * 5 * Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/ 6 */ 7 8 #include <linux/err.h> 9 #include <linux/init.h> 10 #include <linux/io.h> 11 #include <linux/kernel.h> 12 #include <linux/module.h> 13 #include <linux/of.h> 14 #include <linux/platform_device.h> 15 #include <linux/pm_runtime.h> 16 #include <linux/thermal.h> 17 #include <linux/types.h> 18 19 #include "thermal_hwmon.h" 20 21 #define K3_VTM_DEVINFO_PWR0_OFFSET 0x4 22 #define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK 0xf0 23 #define K3_VTM_TMPSENS0_CTRL_OFFSET 0x80 24 #define K3_VTM_REGS_PER_TS 0x10 25 #define K3_VTM_TS_STAT_DTEMP_MASK 0x3ff 26 #define K3_VTM_TMPSENS_CTRL_CBIASSEL BIT(0) 27 #define K3_VTM_TMPSENS_CTRL_SOC BIT(5) 28 #define K3_VTM_TMPSENS_CTRL_CLRZ BIT(6) 29 #define K3_VTM_TMPSENS_CTRL_CLKON_REQ BIT(7) 30 31 #define K3_VTM_ADC_BEGIN_VAL 540 32 #define K3_VTM_ADC_END_VAL 944 33 34 static const int k3_adc_to_temp[] = { 35 -40000, -40000, -40000, -40000, -39800, -39400, -39000, -38600, -38200, 36 -37800, -37400, -37000, -36600, -36200, -35800, -35300, -34700, -34200, 37 -33800, -33400, -33000, -32600, -32200, -31800, -31400, -31000, -30600, 38 -30200, -29800, -29400, -29000, -28600, -28200, -27700, -27100, -26600, 39 -26200, -25800, -25400, -25000, -24600, -24200, -23800, -23400, -23000, 40 -22600, -22200, -21800, -21400, -21000, -20500, -19900, -19400, -19000, 41 -18600, -18200, -17800, -17400, -17000, -16600, -16200, -15800, -15400, 42 -15000, -14600, -14200, -13800, -13400, -13000, -12500, -11900, -11400, 43 -11000, -10600, -10200, -9800, -9400, -9000, -8600, -8200, -7800, -7400, 44 -7000, -6600, -6200, -5800, -5400, -5000, -4500, -3900, -3400, -3000, 45 -2600, -2200, -1800, -1400, -1000, -600, -200, 200, 600, 1000, 1400, 46 1800, 2200, 2600, 3000, 3400, 3900, 4500, 5000, 5400, 5800, 6200, 6600, 47 7000, 7400, 7800, 8200, 8600, 9000, 9400, 9800, 10200, 10600, 11000, 48 11400, 11800, 12200, 12700, 13300, 13800, 14200, 14600, 15000, 15400, 49 15800, 16200, 16600, 17000, 17400, 17800, 18200, 18600, 19000, 19400, 50 19800, 20200, 20600, 21000, 21400, 21900, 22500, 23000, 23400, 23800, 51 24200, 24600, 25000, 25400, 25800, 26200, 26600, 27000, 27400, 27800, 52 28200, 28600, 29000, 29400, 29800, 30200, 30600, 31000, 31400, 31900, 53 32500, 33000, 33400, 33800, 34200, 34600, 35000, 35400, 35800, 36200, 54 36600, 37000, 37400, 37800, 38200, 38600, 39000, 39400, 39800, 40200, 55 40600, 41000, 41400, 41800, 42200, 42600, 43100, 43700, 44200, 44600, 56 45000, 45400, 45800, 46200, 46600, 47000, 47400, 47800, 48200, 48600, 57 49000, 49400, 49800, 50200, 50600, 51000, 51400, 51800, 52200, 52600, 58 53000, 53400, 53800, 54200, 54600, 55000, 55400, 55900, 56500, 57000, 59 57400, 57800, 58200, 58600, 59000, 59400, 59800, 60200, 60600, 61000, 60 61400, 61800, 62200, 62600, 63000, 63400, 63800, 64200, 64600, 65000, 61 65400, 65800, 66200, 66600, 67000, 67400, 67800, 68200, 68600, 69000, 62 69400, 69800, 70200, 70600, 71000, 71500, 72100, 72600, 73000, 73400, 63 73800, 74200, 74600, 75000, 75400, 75800, 76200, 76600, 77000, 77400, 64 77800, 78200, 78600, 79000, 79400, 79800, 80200, 80600, 81000, 81400, 65 81800, 82200, 82600, 83000, 83400, 83800, 84200, 84600, 85000, 85400, 66 85800, 86200, 86600, 87000, 87400, 87800, 88200, 88600, 89000, 89400, 67 89800, 90200, 90600, 91000, 91400, 91800, 92200, 92600, 93000, 93400, 68 93800, 94200, 94600, 95000, 95400, 95800, 96200, 96600, 97000, 97500, 69 98100, 98600, 99000, 99400, 99800, 100200, 100600, 101000, 101400, 70 101800, 102200, 102600, 103000, 103400, 103800, 104200, 104600, 105000, 71 105400, 105800, 106200, 106600, 107000, 107400, 107800, 108200, 108600, 72 109000, 109400, 109800, 110200, 110600, 111000, 111400, 111800, 112200, 73 112600, 113000, 113400, 113800, 114200, 114600, 115000, 115400, 115800, 74 116200, 116600, 117000, 117400, 117800, 118200, 118600, 119000, 119400, 75 119800, 120200, 120600, 121000, 121400, 121800, 122200, 122600, 123000, 76 123400, 123800, 124200, 124600, 124900, 125000, 77 }; 78 79 struct k3_bandgap { 80 void __iomem *base; 81 const struct k3_bandgap_data *conf; 82 }; 83 84 /* common data structures */ 85 struct k3_thermal_data { 86 struct thermal_zone_device *tzd; 87 struct k3_bandgap *bgp; 88 int sensor_id; 89 u32 ctrl_offset; 90 u32 stat_offset; 91 }; 92 93 static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1, 94 unsigned int s2) 95 { 96 int d01 = abs(s0 - s1); 97 int d02 = abs(s0 - s2); 98 int d12 = abs(s1 - s2); 99 100 if (d01 <= d02 && d01 <= d12) 101 return (s0 + s1) / 2; 102 103 if (d02 <= d01 && d02 <= d12) 104 return (s0 + s2) / 2; 105 106 return (s1 + s2) / 2; 107 } 108 109 static int k3_bgp_read_temp(struct k3_thermal_data *devdata, 110 int *temp) 111 { 112 struct k3_bandgap *bgp; 113 unsigned int dtemp, s0, s1, s2; 114 115 bgp = devdata->bgp; 116 117 /* 118 * Errata is applicable for am654 pg 1.0 silicon. There 119 * is a variation of the order for 8-10 degree centigrade. 120 * Work around that by getting the average of two closest 121 * readings out of three readings everytime we want to 122 * report temperatures. 123 * 124 * Errata workaround. 125 */ 126 s0 = readl(bgp->base + devdata->stat_offset) & 127 K3_VTM_TS_STAT_DTEMP_MASK; 128 s1 = readl(bgp->base + devdata->stat_offset) & 129 K3_VTM_TS_STAT_DTEMP_MASK; 130 s2 = readl(bgp->base + devdata->stat_offset) & 131 K3_VTM_TS_STAT_DTEMP_MASK; 132 dtemp = vtm_get_best_value(s0, s1, s2); 133 134 if (dtemp < K3_VTM_ADC_BEGIN_VAL || dtemp > K3_VTM_ADC_END_VAL) 135 return -EINVAL; 136 137 *temp = k3_adc_to_temp[dtemp - K3_VTM_ADC_BEGIN_VAL]; 138 139 return 0; 140 } 141 142 static int k3_thermal_get_temp(struct thermal_zone_device *tz, int *temp) 143 { 144 struct k3_thermal_data *data = thermal_zone_device_priv(tz); 145 int ret = 0; 146 147 ret = k3_bgp_read_temp(data, temp); 148 if (ret) 149 return ret; 150 151 return ret; 152 } 153 154 static const struct thermal_zone_device_ops k3_of_thermal_ops = { 155 .get_temp = k3_thermal_get_temp, 156 }; 157 158 static const struct of_device_id of_k3_bandgap_match[]; 159 160 static int k3_bandgap_probe(struct platform_device *pdev) 161 { 162 int ret = 0, cnt, val, id; 163 struct resource *res; 164 struct device *dev = &pdev->dev; 165 struct k3_bandgap *bgp; 166 struct k3_thermal_data *data; 167 168 if (ARRAY_SIZE(k3_adc_to_temp) != (K3_VTM_ADC_END_VAL + 1 - 169 K3_VTM_ADC_BEGIN_VAL)) 170 return -EINVAL; 171 172 bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL); 173 if (!bgp) 174 return -ENOMEM; 175 176 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 177 bgp->base = devm_ioremap_resource(dev, res); 178 if (IS_ERR(bgp->base)) 179 return PTR_ERR(bgp->base); 180 181 pm_runtime_enable(dev); 182 ret = pm_runtime_get_sync(dev); 183 if (ret < 0) { 184 pm_runtime_put_noidle(dev); 185 pm_runtime_disable(dev); 186 return ret; 187 } 188 189 /* Get the sensor count in the VTM */ 190 val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET); 191 cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK; 192 cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK); 193 194 data = devm_kcalloc(dev, cnt, sizeof(*data), GFP_KERNEL); 195 if (!data) { 196 ret = -ENOMEM; 197 goto err_alloc; 198 } 199 200 /* Register the thermal sensors */ 201 for (id = 0; id < cnt; id++) { 202 data[id].sensor_id = id; 203 data[id].bgp = bgp; 204 data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + 205 id * K3_VTM_REGS_PER_TS; 206 data[id].stat_offset = data[id].ctrl_offset + 0x8; 207 208 val = readl(data[id].bgp->base + data[id].ctrl_offset); 209 val |= (K3_VTM_TMPSENS_CTRL_SOC | 210 K3_VTM_TMPSENS_CTRL_CLRZ | 211 K3_VTM_TMPSENS_CTRL_CLKON_REQ); 212 val &= ~K3_VTM_TMPSENS_CTRL_CBIASSEL; 213 writel(val, data[id].bgp->base + data[id].ctrl_offset); 214 215 data[id].tzd = 216 devm_thermal_of_zone_register(dev, id, 217 &data[id], 218 &k3_of_thermal_ops); 219 if (IS_ERR(data[id].tzd)) { 220 dev_err(dev, "thermal zone device is NULL\n"); 221 ret = PTR_ERR(data[id].tzd); 222 goto err_alloc; 223 } 224 225 devm_thermal_add_hwmon_sysfs(dev, data[id].tzd); 226 } 227 228 229 return 0; 230 231 err_alloc: 232 pm_runtime_put_sync(dev); 233 pm_runtime_disable(dev); 234 235 return ret; 236 } 237 238 static int k3_bandgap_remove(struct platform_device *pdev) 239 { 240 pm_runtime_put_sync(&pdev->dev); 241 pm_runtime_disable(&pdev->dev); 242 243 return 0; 244 } 245 246 static const struct of_device_id of_k3_bandgap_match[] = { 247 { 248 .compatible = "ti,am654-vtm", 249 }, 250 { /* sentinel */ }, 251 }; 252 MODULE_DEVICE_TABLE(of, of_k3_bandgap_match); 253 254 static struct platform_driver k3_bandgap_sensor_driver = { 255 .probe = k3_bandgap_probe, 256 .remove = k3_bandgap_remove, 257 .driver = { 258 .name = "k3-soc-thermal", 259 .of_match_table = of_k3_bandgap_match, 260 }, 261 }; 262 263 module_platform_driver(k3_bandgap_sensor_driver); 264 265 MODULE_DESCRIPTION("K3 bandgap temperature sensor driver"); 266 MODULE_LICENSE("GPL v2"); 267 MODULE_AUTHOR("J Keerthy <j-keerthy@ti.com>"); 268