1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * SPEAr thermal driver.
  4 *
  5 * Copyright (C) 2011-2012 ST Microelectronics
  6 * Author: Vincenzo Frascino <vincenzo.frascino@st.com>
  7 */
  8
  9#include <linux/clk.h>
 10#include <linux/device.h>
 11#include <linux/err.h>
 12#include <linux/io.h>
 13#include <linux/kernel.h>
 14#include <linux/of.h>
 15#include <linux/module.h>
 16#include <linux/platform_device.h>
 17#include <linux/thermal.h>
 18
 19#define MD_FACTOR	1000
 20
 21/* SPEAr Thermal Sensor Dev Structure */
 22struct spear_thermal_dev {
 23	/* pointer to base address of the thermal sensor */
 24	void __iomem *thermal_base;
 25	/* clk structure */
 26	struct clk *clk;
 27	/* pointer to thermal flags */
 28	unsigned int flags;
 29};
 30
 31static inline int thermal_get_temp(struct thermal_zone_device *thermal,
 32				int *temp)
 33{
 34	struct spear_thermal_dev *stdev = thermal_zone_device_priv(thermal);
 35
 36	/*
 37	 * Data are ready to be read after 628 usec from POWERDOWN signal
 38	 * (PDN) = 1
 39	 */
 40	*temp = (readl_relaxed(stdev->thermal_base) & 0x7F) * MD_FACTOR;
 41	return 0;
 42}
 43
 44static struct thermal_zone_device_ops ops = {
 45	.get_temp = thermal_get_temp,
 46};
 47
 48static int __maybe_unused spear_thermal_suspend(struct device *dev)
 49{
 50	struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
 51	struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
 52	unsigned int actual_mask = 0;
 53
 54	/* Disable SPEAr Thermal Sensor */
 55	actual_mask = readl_relaxed(stdev->thermal_base);
 56	writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
 57
 58	clk_disable(stdev->clk);
 59	dev_info(dev, "Suspended.\n");
 60
 61	return 0;
 62}
 63
 64static int __maybe_unused spear_thermal_resume(struct device *dev)
 65{
 66	struct thermal_zone_device *spear_thermal = dev_get_drvdata(dev);
 67	struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
 68	unsigned int actual_mask = 0;
 69	int ret = 0;
 70
 71	ret = clk_enable(stdev->clk);
 72	if (ret) {
 73		dev_err(dev, "Can't enable clock\n");
 74		return ret;
 75	}
 76
 77	/* Enable SPEAr Thermal Sensor */
 78	actual_mask = readl_relaxed(stdev->thermal_base);
 79	writel_relaxed(actual_mask | stdev->flags, stdev->thermal_base);
 80
 81	dev_info(dev, "Resumed.\n");
 82
 83	return 0;
 84}
 85
 86static SIMPLE_DEV_PM_OPS(spear_thermal_pm_ops, spear_thermal_suspend,
 87		spear_thermal_resume);
 88
 89static int spear_thermal_probe(struct platform_device *pdev)
 90{
 91	struct thermal_zone_device *spear_thermal = NULL;
 92	struct spear_thermal_dev *stdev;
 93	struct device_node *np = pdev->dev.of_node;
 94	int ret = 0, val;
 95
 96	if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
 97		dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
 98		return -EINVAL;
 99	}
100
101	stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
102	if (!stdev)
103		return -ENOMEM;
104
105	/* Enable thermal sensor */
106	stdev->thermal_base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
107	if (IS_ERR(stdev->thermal_base))
108		return PTR_ERR(stdev->thermal_base);
109
110	stdev->clk = devm_clk_get(&pdev->dev, NULL);
111	if (IS_ERR(stdev->clk)) {
112		dev_err(&pdev->dev, "Can't get clock\n");
113		return PTR_ERR(stdev->clk);
114	}
115
116	ret = clk_enable(stdev->clk);
117	if (ret) {
118		dev_err(&pdev->dev, "Can't enable clock\n");
119		return ret;
120	}
121
122	stdev->flags = val;
123	writel_relaxed(stdev->flags, stdev->thermal_base);
124
125	spear_thermal = thermal_tripless_zone_device_register("spear_thermal",
126							      stdev, &ops, NULL);
127	if (IS_ERR(spear_thermal)) {
128		dev_err(&pdev->dev, "thermal zone device is NULL\n");
129		ret = PTR_ERR(spear_thermal);
130		goto disable_clk;
131	}
132	ret = thermal_zone_device_enable(spear_thermal);
133	if (ret) {
134		dev_err(&pdev->dev, "Cannot enable thermal zone\n");
135		goto unregister_tzd;
136	}
137
138	platform_set_drvdata(pdev, spear_thermal);
139
140	dev_info(&pdev->dev, "Thermal Sensor Loaded at: 0x%p.\n",
141			stdev->thermal_base);
142
143	return 0;
144
145unregister_tzd:
146	thermal_zone_device_unregister(spear_thermal);
147disable_clk:
148	clk_disable(stdev->clk);
149
150	return ret;
151}
152
153static void spear_thermal_exit(struct platform_device *pdev)
154{
155	unsigned int actual_mask = 0;
156	struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
157	struct spear_thermal_dev *stdev = thermal_zone_device_priv(spear_thermal);
158
159	thermal_zone_device_unregister(spear_thermal);
160
161	/* Disable SPEAr Thermal Sensor */
162	actual_mask = readl_relaxed(stdev->thermal_base);
163	writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
164
165	clk_disable(stdev->clk);
166}
167
168static const struct of_device_id spear_thermal_id_table[] = {
169	{ .compatible = "st,thermal-spear1340" },
170	{}
171};
172MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
173
174static struct platform_driver spear_thermal_driver = {
175	.probe = spear_thermal_probe,
176	.remove = spear_thermal_exit,
177	.driver = {
178		.name = "spear_thermal",
179		.pm = &spear_thermal_pm_ops,
180		.of_match_table = spear_thermal_id_table,
181	},
182};
183
184module_platform_driver(spear_thermal_driver);
185
186MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
187MODULE_DESCRIPTION("SPEAr thermal driver");
188MODULE_LICENSE("GPL");