1 /*
2  * ST Thermal Sensor Driver for memory mapped sensors.
3  * Author: Ajit Pal Singh <ajitpal.singh@st.com>
4  *
5  * Copyright (C) 2003-2014 STMicroelectronics (R&D) Limited
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  */
12 
13 #include <linux/of.h>
14 #include <linux/module.h>
15 
16 #include "st_thermal.h"
17 
18 #define STIH416_MPE_CONF			0x0
19 #define STIH416_MPE_STATUS			0x4
20 #define STIH416_MPE_INT_THRESH			0x8
21 #define STIH416_MPE_INT_EN			0xC
22 
23 /* Power control bits for the memory mapped thermal sensor */
24 #define THERMAL_PDN				BIT(4)
25 #define THERMAL_SRSTN				BIT(10)
26 
27 static const struct reg_field st_mmap_thermal_regfields[MAX_REGFIELDS] = {
28 	/*
29 	 * According to the STIH416 MPE temp sensor data sheet -
30 	 * the PDN (Power Down Bit) and SRSTN (Soft Reset Bit) need to be
31 	 * written simultaneously for powering on and off the temperature
32 	 * sensor. regmap_update_bits() will be used to update the register.
33 	 */
34 	[INT_THRESH_HI]	= REG_FIELD(STIH416_MPE_INT_THRESH, 	0,  7),
35 	[DCORRECT]	= REG_FIELD(STIH416_MPE_CONF,		5,  9),
36 	[OVERFLOW]	= REG_FIELD(STIH416_MPE_STATUS,		9,  9),
37 	[DATA]		= REG_FIELD(STIH416_MPE_STATUS,		11, 18),
38 	[INT_ENABLE]	= REG_FIELD(STIH416_MPE_INT_EN,		0,  0),
39 };
40 
41 static irqreturn_t st_mmap_thermal_trip_handler(int irq, void *sdata)
42 {
43 	struct st_thermal_sensor *sensor = sdata;
44 
45 	thermal_zone_device_update(sensor->thermal_dev);
46 
47 	return IRQ_HANDLED;
48 }
49 
50 /* Private ops for the Memory Mapped based thermal sensors */
51 static int st_mmap_power_ctrl(struct st_thermal_sensor *sensor,
52 			      enum st_thermal_power_state power_state)
53 {
54 	const unsigned int mask = (THERMAL_PDN | THERMAL_SRSTN);
55 	const unsigned int val = power_state ? mask : 0;
56 
57 	return regmap_update_bits(sensor->regmap, STIH416_MPE_CONF, mask, val);
58 }
59 
60 static int st_mmap_alloc_regfields(struct st_thermal_sensor *sensor)
61 {
62 	struct device *dev = sensor->dev;
63 	struct regmap *regmap = sensor->regmap;
64 	const struct reg_field *reg_fields = sensor->cdata->reg_fields;
65 
66 	sensor->int_thresh_hi = devm_regmap_field_alloc(dev, regmap,
67 						reg_fields[INT_THRESH_HI]);
68 	sensor->int_enable = devm_regmap_field_alloc(dev, regmap,
69 						reg_fields[INT_ENABLE]);
70 
71 	if (IS_ERR(sensor->int_thresh_hi) || IS_ERR(sensor->int_enable)) {
72 		dev_err(dev, "failed to alloc mmap regfields\n");
73 		return -EINVAL;
74 	}
75 
76 	return 0;
77 }
78 
79 static int st_mmap_enable_irq(struct st_thermal_sensor *sensor)
80 {
81 	int ret;
82 
83 	/* Set upper critical threshold */
84 	ret = regmap_field_write(sensor->int_thresh_hi,
85 				 sensor->cdata->crit_temp -
86 				 sensor->cdata->temp_adjust_val);
87 	if (ret)
88 		return ret;
89 
90 	return regmap_field_write(sensor->int_enable, 1);
91 }
92 
93 static int st_mmap_register_enable_irq(struct st_thermal_sensor *sensor)
94 {
95 	struct device *dev = sensor->dev;
96 	struct platform_device *pdev = to_platform_device(dev);
97 	int ret;
98 
99 	sensor->irq = platform_get_irq(pdev, 0);
100 	if (sensor->irq < 0) {
101 		dev_err(dev, "failed to register IRQ\n");
102 		return sensor->irq;
103 	}
104 
105 	ret = devm_request_threaded_irq(dev, sensor->irq,
106 					NULL, st_mmap_thermal_trip_handler,
107 					IRQF_TRIGGER_RISING | IRQF_ONESHOT,
108 					dev->driver->name, sensor);
109 	if (ret) {
110 		dev_err(dev, "failed to register IRQ %d\n", sensor->irq);
111 		return ret;
112 	}
113 
114 	return st_mmap_enable_irq(sensor);
115 }
116 
117 static const struct regmap_config st_416mpe_regmap_config = {
118 	.reg_bits = 32,
119 	.val_bits = 32,
120 	.reg_stride = 4,
121 };
122 
123 static int st_mmap_regmap_init(struct st_thermal_sensor *sensor)
124 {
125 	struct device *dev = sensor->dev;
126 	struct platform_device *pdev = to_platform_device(dev);
127 	struct resource *res;
128 
129 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
130 	if (!res) {
131 		dev_err(dev, "no memory resources defined\n");
132 		return -ENODEV;
133 	}
134 
135 	sensor->mmio_base = devm_ioremap_resource(dev, res);
136 	if (IS_ERR(sensor->mmio_base)) {
137 		dev_err(dev, "failed to remap IO\n");
138 		return PTR_ERR(sensor->mmio_base);
139 	}
140 
141 	sensor->regmap = devm_regmap_init_mmio(dev, sensor->mmio_base,
142 				&st_416mpe_regmap_config);
143 	if (IS_ERR(sensor->regmap)) {
144 		dev_err(dev, "failed to initialise regmap\n");
145 		return PTR_ERR(sensor->regmap);
146 	}
147 
148 	return 0;
149 }
150 
151 static const struct st_thermal_sensor_ops st_mmap_sensor_ops = {
152 	.power_ctrl		= st_mmap_power_ctrl,
153 	.alloc_regfields	= st_mmap_alloc_regfields,
154 	.regmap_init		= st_mmap_regmap_init,
155 	.register_enable_irq	= st_mmap_register_enable_irq,
156 	.enable_irq		= st_mmap_enable_irq,
157 };
158 
159 /* Compatible device data stih416 mpe thermal sensor */
160 const struct st_thermal_compat_data st_416mpe_cdata = {
161 	.reg_fields		= st_mmap_thermal_regfields,
162 	.ops			= &st_mmap_sensor_ops,
163 	.calibration_val	= 14,
164 	.temp_adjust_val	= -95,
165 	.crit_temp		= 120,
166 };
167 
168 /* Compatible device data stih407 thermal sensor */
169 const struct st_thermal_compat_data st_407_cdata = {
170 	.reg_fields		= st_mmap_thermal_regfields,
171 	.ops			= &st_mmap_sensor_ops,
172 	.calibration_val	= 16,
173 	.temp_adjust_val	= -95,
174 	.crit_temp		= 120,
175 };
176 
177 static struct of_device_id st_mmap_thermal_of_match[] = {
178 	{ .compatible = "st,stih416-mpe-thermal", .data = &st_416mpe_cdata },
179 	{ .compatible = "st,stih407-thermal",     .data = &st_407_cdata },
180 	{ /* sentinel */ }
181 };
182 MODULE_DEVICE_TABLE(of, st_mmap_thermal_of_match);
183 
184 int st_mmap_probe(struct platform_device *pdev)
185 {
186 	return st_thermal_register(pdev,  st_mmap_thermal_of_match);
187 }
188 
189 int st_mmap_remove(struct platform_device *pdev)
190 {
191 	return st_thermal_unregister(pdev);
192 }
193 
194 static struct platform_driver st_mmap_thermal_driver = {
195 	.driver = {
196 		.name	= "st_thermal_mmap",
197 		.pm     = &st_thermal_pm_ops,
198 		.of_match_table = st_mmap_thermal_of_match,
199 	},
200 	.probe		= st_mmap_probe,
201 	.remove		= st_mmap_remove,
202 };
203 
204 module_platform_driver(st_mmap_thermal_driver);
205 
206 MODULE_AUTHOR("STMicroelectronics (R&D) Limited <ajitpal.singh@st.com>");
207 MODULE_DESCRIPTION("STMicroelectronics STi SoC Thermal Sensor Driver");
208 MODULE_LICENSE("GPL v2");
209