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->devdata;
 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 = spear_thermal->devdata;
 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 = spear_thermal->devdata;
 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	struct resource *res;
 95	int ret = 0, val;
 96
 97	if (!np || !of_property_read_u32(np, "st,thermal-flags", &val)) {
 98		dev_err(&pdev->dev, "Failed: DT Pdata not passed\n");
 99		return -EINVAL;
100	}
101
102	stdev = devm_kzalloc(&pdev->dev, sizeof(*stdev), GFP_KERNEL);
103	if (!stdev)
104		return -ENOMEM;
105
106	/* Enable thermal sensor */
107	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
108	stdev->thermal_base = devm_ioremap_resource(&pdev->dev, res);
109	if (IS_ERR(stdev->thermal_base))
110		return PTR_ERR(stdev->thermal_base);
111
112	stdev->clk = devm_clk_get(&pdev->dev, NULL);
113	if (IS_ERR(stdev->clk)) {
114		dev_err(&pdev->dev, "Can't get clock\n");
115		return PTR_ERR(stdev->clk);
116	}
117
118	ret = clk_enable(stdev->clk);
119	if (ret) {
120		dev_err(&pdev->dev, "Can't enable clock\n");
121		return ret;
122	}
123
124	stdev->flags = val;
125	writel_relaxed(stdev->flags, stdev->thermal_base);
126
127	spear_thermal = thermal_zone_device_register("spear_thermal", 0, 0,
128				stdev, &ops, NULL, 0, 0);
129	if (IS_ERR(spear_thermal)) {
130		dev_err(&pdev->dev, "thermal zone device is NULL\n");
131		ret = PTR_ERR(spear_thermal);
132		goto disable_clk;
133	}
134	ret = thermal_zone_device_enable(spear_thermal);
135	if (ret) {
136		dev_err(&pdev->dev, "Cannot enable thermal zone\n");
137		goto unregister_tzd;
138	}
139
140	platform_set_drvdata(pdev, spear_thermal);
141
142	dev_info(&spear_thermal->device, "Thermal Sensor Loaded at: 0x%p.\n",
143			stdev->thermal_base);
144
145	return 0;
146
147unregister_tzd:
148	thermal_zone_device_unregister(spear_thermal);
149disable_clk:
150	clk_disable(stdev->clk);
151
152	return ret;
153}
154
155static int spear_thermal_exit(struct platform_device *pdev)
156{
157	unsigned int actual_mask = 0;
158	struct thermal_zone_device *spear_thermal = platform_get_drvdata(pdev);
159	struct spear_thermal_dev *stdev = spear_thermal->devdata;
160
161	thermal_zone_device_unregister(spear_thermal);
162
163	/* Disable SPEAr Thermal Sensor */
164	actual_mask = readl_relaxed(stdev->thermal_base);
165	writel_relaxed(actual_mask & ~stdev->flags, stdev->thermal_base);
166
167	clk_disable(stdev->clk);
168
169	return 0;
170}
171
172static const struct of_device_id spear_thermal_id_table[] = {
173	{ .compatible = "st,thermal-spear1340" },
174	{}
175};
176MODULE_DEVICE_TABLE(of, spear_thermal_id_table);
177
178static struct platform_driver spear_thermal_driver = {
179	.probe = spear_thermal_probe,
180	.remove = spear_thermal_exit,
181	.driver = {
182		.name = "spear_thermal",
183		.pm = &spear_thermal_pm_ops,
184		.of_match_table = spear_thermal_id_table,
185	},
186};
187
188module_platform_driver(spear_thermal_driver);
189
190MODULE_AUTHOR("Vincenzo Frascino <vincenzo.frascino@st.com>");
191MODULE_DESCRIPTION("SPEAr thermal driver");
192MODULE_LICENSE("GPL");