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
 21struct sr_tmon {
 22	unsigned int crit_temp;
 23	unsigned int tmon_id;
 24	struct sr_thermal *priv;
 25};
 26
 27struct sr_thermal {
 28	void __iomem *regs;
 29	unsigned int max_crit_temp;
 30	struct sr_tmon tmon[SR_TMON_MAX_LIST];
 31};
 32
 33static int sr_get_temp(struct thermal_zone_device *tz, int *temp)
 34{
 35	struct sr_tmon *tmon = thermal_zone_device_priv(tz);
 36	struct sr_thermal *sr_thermal = tmon->priv;
 37
 38	*temp = readl(sr_thermal->regs + SR_TMON_TEMP_BASE(tmon->tmon_id));
 39
 40	return 0;
 41}
 42
 43static const struct thermal_zone_device_ops sr_tz_ops = {
 44	.get_temp = sr_get_temp,
 45};
 46
 47static int sr_thermal_probe(struct platform_device *pdev)
 48{
 49	struct device *dev = &pdev->dev;
 50	struct thermal_zone_device *tz;
 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	if (!res)
 64		return -ENOENT;
 65
 66	sr_thermal->regs = (void __iomem *)devm_memremap(&pdev->dev, res->start,
 67							 resource_size(res),
 68							 MEMREMAP_WB);
 69	if (IS_ERR(sr_thermal->regs)) {
 70		dev_err(dev, "failed to get io address\n");
 71		return PTR_ERR(sr_thermal->regs);
 72	}
 73
 74	ret = device_property_read_u32(dev, "brcm,tmon-mask", &sr_tmon_list);
 75	if (ret)
 76		return ret;
 77
 78	tmon = sr_thermal->tmon;
 79	for (i = 0; i < SR_TMON_MAX_LIST; i++, tmon++) {
 80		if (!(sr_tmon_list & BIT(i)))
 81			continue;
 82
 83		/* Flush temperature registers */
 84		writel(0, sr_thermal->regs + SR_TMON_TEMP_BASE(i));
 85		tmon->tmon_id = i;
 86		tmon->priv = sr_thermal;
 87		tz = devm_thermal_of_zone_register(dev, i, tmon,
 88						   &sr_tz_ops);
 89		if (IS_ERR(tz))
 90			return PTR_ERR(tz);
 91
 92		dev_dbg(dev, "thermal sensor %d registered\n", i);
 93	}
 94
 95	return 0;
 96}
 97
 98static const struct of_device_id sr_thermal_of_match[] = {
 99	{ .compatible = "brcm,sr-thermal", },
100	{},
101};
102MODULE_DEVICE_TABLE(of, sr_thermal_of_match);
103
104static struct platform_driver sr_thermal_driver = {
105	.probe		= sr_thermal_probe,
106	.driver = {
107		.name = "sr-thermal",
108		.of_match_table = sr_thermal_of_match,
109	},
110};
111module_platform_driver(sr_thermal_driver);
112
113MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
114MODULE_DESCRIPTION("Stingray thermal driver");
115MODULE_LICENSE("GPL v2");