xref: /openbmc/u-boot/drivers/power/exynos-tmu.c (revision 713cb680)
1 /*
2  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
3  *      http://www.samsung.com
4  * Akshay Saraswat <akshay.s@samsung.com>
5  *
6  * EXYNOS - Thermal Management Unit
7  *
8  * See file CREDITS for list of people who contributed to this
9  * project.
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License version 2 as
13  * published by the Free Software Foundation.
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
17  * MA 02111-1307 USA
18  */
19 
20 #include <common.h>
21 #include <errno.h>
22 #include <fdtdec.h>
23 #include <tmu.h>
24 #include <asm/arch/tmu.h>
25 #include <asm/arch/power.h>
26 
27 #define TRIMINFO_RELOAD		1
28 #define CORE_EN			1
29 #define THERM_TRIP_EN		(1 << 12)
30 
31 #define INTEN_RISE0		1
32 #define INTEN_RISE1		(1 << 4)
33 #define INTEN_RISE2		(1 << 8)
34 #define INTEN_FALL0		(1 << 16)
35 #define INTEN_FALL1		(1 << 20)
36 #define INTEN_FALL2		(1 << 24)
37 
38 #define TRIM_INFO_MASK		0xff
39 
40 #define INTCLEAR_RISE0		1
41 #define INTCLEAR_RISE1		(1 << 4)
42 #define INTCLEAR_RISE2		(1 << 8)
43 #define INTCLEAR_FALL0		(1 << 16)
44 #define INTCLEAR_FALL1		(1 << 20)
45 #define INTCLEAR_FALL2		(1 << 24)
46 #define INTCLEARALL		(INTCLEAR_RISE0 | INTCLEAR_RISE1 | \
47 				 INTCLEAR_RISE2 | INTCLEAR_FALL0 | \
48 				 INTCLEAR_FALL1 | INTCLEAR_FALL2)
49 
50 /* Tmeperature threshold values for various thermal events */
51 struct temperature_params {
52 	/* minimum value in temperature code range */
53 	unsigned min_val;
54 	/* maximum value in temperature code range */
55 	unsigned max_val;
56 	/* temperature threshold to start warning */
57 	unsigned start_warning;
58 	/* temperature threshold CPU tripping */
59 	unsigned start_tripping;
60 	/* temperature threshold for HW tripping */
61 	unsigned hardware_tripping;
62 };
63 
64 /* Pre-defined values and thresholds for calibration of current temperature */
65 struct tmu_data {
66 	/* pre-defined temperature thresholds */
67 	struct temperature_params ts;
68 	/* pre-defined efuse range minimum value */
69 	unsigned efuse_min_value;
70 	/* pre-defined efuse value for temperature calibration */
71 	unsigned efuse_value;
72 	/* pre-defined efuse range maximum value */
73 	unsigned efuse_max_value;
74 	/* current temperature sensing slope */
75 	unsigned slope;
76 };
77 
78 /* TMU device specific details and status */
79 struct tmu_info {
80 	/* base Address for the TMU */
81 	struct exynos5_tmu_reg *tmu_base;
82 	/* mux Address for the TMU */
83 	int tmu_mux;
84 	/* pre-defined values for calibration and thresholds */
85 	struct tmu_data data;
86 	/* value required for triminfo_25 calibration */
87 	unsigned te1;
88 	/* value required for triminfo_85 calibration */
89 	unsigned te2;
90 	/* Value for measured data calibration */
91 	int dc_value;
92 	/* enum value indicating status of the TMU */
93 	int tmu_state;
94 };
95 
96 /* Global struct tmu_info variable to store init values */
97 static struct tmu_info gbl_info;
98 
99 /*
100  * Get current temperature code from register,
101  * then calculate and calibrate it's value
102  * in degree celsius.
103  *
104  * @return	current temperature of the chip as sensed by TMU
105  */
106 static int get_cur_temp(struct tmu_info *info)
107 {
108 	struct exynos5_tmu_reg *reg = info->tmu_base;
109 	ulong start;
110 	int cur_temp = 0;
111 
112 	/*
113 	 * Temperature code range between min 25 and max 125.
114 	 * May run more than once for first call as initial sensing
115 	 * has not yet happened.
116 	 */
117 	if (info->tmu_state == TMU_STATUS_NORMAL) {
118 		start = get_timer(0);
119 		do {
120 			cur_temp = readl(&reg->current_temp) & 0xff;
121 		} while ((cur_temp == 0) || (get_timer(start) > 100));
122 	}
123 
124 	if (cur_temp == 0)
125 		return cur_temp;
126 
127 	/* Calibrate current temperature */
128 	cur_temp = cur_temp - info->te1 + info->dc_value;
129 
130 	return cur_temp;
131 }
132 
133 /*
134  * Monitors status of the TMU device and exynos temperature
135  *
136  * @param temp	pointer to the current temperature value
137  * @return	enum tmu_status_t value, code indicating event to execute
138  */
139 enum tmu_status_t tmu_monitor(int *temp)
140 {
141 	int cur_temp;
142 	struct tmu_data *data = &gbl_info.data;
143 
144 	if (gbl_info.tmu_state == TMU_STATUS_INIT)
145 		return TMU_STATUS_INIT;
146 
147 	/* Read current temperature of the SOC */
148 	cur_temp = get_cur_temp(&gbl_info);
149 
150 	if (!cur_temp)
151 		goto out;
152 
153 	*temp = cur_temp;
154 
155 	/* Temperature code lies between min 25 and max 125 */
156 	if ((cur_temp >= data->ts.start_tripping) &&
157 	    (cur_temp <= data->ts.max_val))
158 		return TMU_STATUS_TRIPPED;
159 
160 	if (cur_temp >= data->ts.start_warning)
161 		return TMU_STATUS_WARNING;
162 
163 	if ((cur_temp < data->ts.start_warning) &&
164 	    (cur_temp >= data->ts.min_val))
165 		return TMU_STATUS_NORMAL;
166 
167  out:
168 	/* Temperature code does not lie between min 25 and max 125 */
169 	gbl_info.tmu_state = TMU_STATUS_INIT;
170 	debug("EXYNOS_TMU: Thermal reading failed\n");
171 	return TMU_STATUS_INIT;
172 }
173 
174 /*
175  * Get TMU specific pre-defined values from FDT
176  *
177  * @param info	pointer to the tmu_info struct
178  * @param blob  FDT blob
179  * @return	int value, 0 for success
180  */
181 static int get_tmu_fdt_values(struct tmu_info *info, const void *blob)
182 {
183 #ifdef CONFIG_OF_CONTROL
184 	fdt_addr_t addr;
185 	int node;
186 	int error = 0;
187 
188 	/* Get the node from FDT for TMU */
189 	node = fdtdec_next_compatible(blob, 0,
190 				      COMPAT_SAMSUNG_EXYNOS_TMU);
191 	if (node < 0) {
192 		debug("EXYNOS_TMU: No node for tmu in device tree\n");
193 		return -1;
194 	}
195 
196 	/*
197 	 * Get the pre-defined TMU specific values from FDT.
198 	 * All of these are expected to be correct otherwise
199 	 * miscalculation of register values in tmu_setup_parameters
200 	 * may result in misleading current temperature.
201 	 */
202 	addr = fdtdec_get_addr(blob, node, "reg");
203 	if (addr == FDT_ADDR_T_NONE) {
204 		debug("%s: Missing tmu-base\n", __func__);
205 		return -1;
206 	}
207 	info->tmu_base = (struct exynos5_tmu_reg *)addr;
208 
209 	/* Optional field. */
210 	info->tmu_mux = fdtdec_get_int(blob,
211 				node, "samsung,mux", -1);
212 	/* Take default value as per the user manual b(110) */
213 	if (info->tmu_mux == -1)
214 		info->tmu_mux = 0x6;
215 
216 	info->data.ts.min_val = fdtdec_get_int(blob,
217 				node, "samsung,min-temp", -1);
218 	error |= (info->data.ts.min_val == -1);
219 	info->data.ts.max_val = fdtdec_get_int(blob,
220 				node, "samsung,max-temp", -1);
221 	error |= (info->data.ts.max_val == -1);
222 	info->data.ts.start_warning = fdtdec_get_int(blob,
223 				node, "samsung,start-warning", -1);
224 	error |= (info->data.ts.start_warning == -1);
225 	info->data.ts.start_tripping = fdtdec_get_int(blob,
226 				node, "samsung,start-tripping", -1);
227 	error |= (info->data.ts.start_tripping == -1);
228 	info->data.ts.hardware_tripping = fdtdec_get_int(blob,
229 				node, "samsung,hw-tripping", -1);
230 	error |= (info->data.ts.hardware_tripping == -1);
231 	info->data.efuse_min_value = fdtdec_get_int(blob,
232 				node, "samsung,efuse-min-value", -1);
233 	error |= (info->data.efuse_min_value == -1);
234 	info->data.efuse_value = fdtdec_get_int(blob,
235 				node, "samsung,efuse-value", -1);
236 	error |= (info->data.efuse_value == -1);
237 	info->data.efuse_max_value = fdtdec_get_int(blob,
238 				node, "samsung,efuse-max-value", -1);
239 	error |= (info->data.efuse_max_value == -1);
240 	info->data.slope = fdtdec_get_int(blob,
241 				node, "samsung,slope", -1);
242 	error |= (info->data.slope == -1);
243 	info->dc_value = fdtdec_get_int(blob,
244 				node, "samsung,dc-value", -1);
245 	error |= (info->dc_value == -1);
246 
247 	if (error) {
248 		debug("fail to get tmu node properties\n");
249 		return -1;
250 	}
251 #else
252 	/* Non DT support may never be added. Just in case  */
253 	return -1;
254 #endif
255 
256 	return 0;
257 }
258 
259 /*
260  * Calibrate and calculate threshold values and
261  * enable interrupt levels
262  *
263  * @param	info pointer to the tmu_info struct
264  */
265 static void tmu_setup_parameters(struct tmu_info *info)
266 {
267 	unsigned te_code, con;
268 	unsigned warning_code, trip_code, hwtrip_code;
269 	unsigned cooling_temp;
270 	unsigned rising_value;
271 	struct tmu_data *data = &info->data;
272 	struct exynos5_tmu_reg *reg = info->tmu_base;
273 
274 	/* Must reload for reading efuse value from triminfo register */
275 	writel(TRIMINFO_RELOAD, &reg->triminfo_control);
276 
277 	/* Get the compensation parameter */
278 	te_code = readl(&reg->triminfo);
279 	info->te1 = te_code & TRIM_INFO_MASK;
280 	info->te2 = ((te_code >> 8) & TRIM_INFO_MASK);
281 
282 	if ((data->efuse_min_value > info->te1) ||
283 			(info->te1 > data->efuse_max_value)
284 			||  (info->te2 != 0))
285 		info->te1 = data->efuse_value;
286 
287 	/* Get RISING & FALLING Threshold value */
288 	warning_code = data->ts.start_warning
289 			+ info->te1 - info->dc_value;
290 	trip_code = data->ts.start_tripping
291 			+ info->te1 - info->dc_value;
292 	hwtrip_code = data->ts.hardware_tripping
293 			+ info->te1 - info->dc_value;
294 
295 	cooling_temp = 0;
296 
297 	rising_value = ((warning_code << 8) |
298 			(trip_code << 16) |
299 			(hwtrip_code << 24));
300 
301 	/* Set interrupt level */
302 	writel(rising_value, &reg->threshold_temp_rise);
303 	writel(cooling_temp, &reg->threshold_temp_fall);
304 
305 	/*
306 	 * Init TMU control tuning parameters
307 	 * [28:24] VREF - Voltage reference
308 	 * [15:13] THERM_TRIP_MODE - Tripping mode
309 	 * [12] THERM_TRIP_EN - Thermal tripping enable
310 	 * [11:8] BUF_SLOPE_SEL - Gain of amplifier
311 	 * [6] THERM_TRIP_BY_TQ_EN - Tripping by TQ pin
312 	 */
313 	writel(data->slope, &reg->tmu_control);
314 
315 	writel(INTCLEARALL, &reg->intclear);
316 
317 	/* TMU core enable */
318 	con = readl(&reg->tmu_control);
319 	con |= THERM_TRIP_EN | CORE_EN | (info->tmu_mux << 20);
320 
321 	writel(con, &reg->tmu_control);
322 
323 	/* Enable HW thermal trip */
324 	set_hw_thermal_trip();
325 
326 	/* LEV1 LEV2 interrupt enable */
327 	writel(INTEN_RISE1 | INTEN_RISE2, &reg->inten);
328 }
329 
330 /*
331  * Initialize TMU device
332  *
333  * @param blob  FDT blob
334  * @return	int value, 0 for success
335  */
336 int tmu_init(const void *blob)
337 {
338 	gbl_info.tmu_state = TMU_STATUS_INIT;
339 	if (get_tmu_fdt_values(&gbl_info, blob) < 0)
340 		goto ret;
341 
342 	tmu_setup_parameters(&gbl_info);
343 	gbl_info.tmu_state = TMU_STATUS_NORMAL;
344 ret:
345 	return gbl_info.tmu_state;
346 }
347