drivers/thermal/k3_bandgap.c

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