drivers/thermal/broadcom/sr-thermal.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2018 Broadcom
   4  */
   5
   6 #include <linux/module.h>
   7 #include <linux/of_address.h>
   8 #include <linux/platform_device.h>
   9 #include <linux/thermal.h>
  10
  11 /*
  12  * In stingray thermal IO memory,
  13  * Total Number of available TMONs MASK is at offset 0
  14  * temperature registers BASE is at 4 byte offset.
  15  * Each TMON temperature register size is 4.
  16  */
  17 #define SR_TMON_TEMP_BASE(id)   ((id) * 0x4)
  18
  19 #define SR_TMON_MAX_LIST        6
  20
  21 struct sr_tmon {
  22         struct thermal_zone_device *tz;
  23         unsigned int crit_temp;
  24         unsigned int tmon_id;
  25         struct sr_thermal *priv;
  26 };
  27
  28 struct sr_thermal {
  29         void __iomem *regs;
  30         unsigned int max_crit_temp;
  31         struct sr_tmon tmon[SR_TMON_MAX_LIST];
  32 };
  33
  34 static int sr_get_temp(void *data, int *temp)
  35 {
  36         struct sr_tmon *tmon = data;
  37         struct sr_thermal *sr_thermal = tmon->priv;
  38
  39         *temp = readl(sr_thermal->regs + SR_TMON_TEMP_BASE(tmon->tmon_id));
  40
  41         return 0;
  42 }
  43
  44 static const struct thermal_zone_of_device_ops sr_tz_ops = {
  45         .get_temp = sr_get_temp,
  46 };
  47
  48 static int sr_thermal_probe(struct platform_device *pdev)
  49 {
  50         struct device *dev = &pdev->dev;
  51         struct sr_thermal *sr_thermal;
  52         struct sr_tmon *tmon;
  53         struct resource *res;
  54         u32 sr_tmon_list = 0;
  55         unsigned int i;
  56         int ret;
  57
  58         sr_thermal = devm_kzalloc(dev, sizeof(*sr_thermal), GFP_KERNEL);
  59         if (!sr_thermal)
  60                 return -ENOMEM;
  61
  62         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  63         sr_thermal->regs = (void __iomem *)devm_memremap(&pdev->dev, res->start,
  64                                                          resource_size(res),
  65                                                          MEMREMAP_WB);
  66         if (IS_ERR(sr_thermal->regs)) {
  67                 dev_err(dev, "failed to get io address\n");
  68                 return PTR_ERR(sr_thermal->regs);
  69         }
  70
  71         ret = device_property_read_u32(dev, "brcm,tmon-mask", &sr_tmon_list);
  72         if (ret)
  73                 return ret;
  74
  75         tmon = sr_thermal->tmon;
  76         for (i = 0; i < SR_TMON_MAX_LIST; i++, tmon++) {
  77                 if (!(sr_tmon_list & BIT(i)))
  78                         continue;
  79
  80                 /* Flush temperature registers */
  81                 writel(0, sr_thermal->regs + SR_TMON_TEMP_BASE(i));
  82                 tmon->tmon_id = i;
  83                 tmon->priv = sr_thermal;
  84                 tmon->tz = devm_thermal_zone_of_sensor_register(dev, i, tmon,
  85                                                                 &sr_tz_ops);
  86                 if (IS_ERR(tmon->tz))
  87                         return PTR_ERR(tmon->tz);
  88
  89                 dev_dbg(dev, "thermal sensor %d registered\n", i);
  90         }
  91         platform_set_drvdata(pdev, sr_thermal);
  92
  93         return 0;
  94 }
  95
  96 static const struct of_device_id sr_thermal_of_match[] = {
  97         { .compatible = "brcm,sr-thermal", },
  98         {},
  99 };
 100 MODULE_DEVICE_TABLE(of, sr_thermal_of_match);
 101
 102 static struct platform_driver sr_thermal_driver = {
 103         .probe          = sr_thermal_probe,
 104         .driver = {
 105                 .name = "sr-thermal",
 106                 .of_match_table = sr_thermal_of_match,
 107         },
 108 };
 109 module_platform_driver(sr_thermal_driver);
 110
 111 MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
 112 MODULE_DESCRIPTION("Stingray thermal driver");
 113 MODULE_LICENSE("GPL v2");