xref: /netbsd-src/sys/dev/i2c/adadc.c (revision 16dce51364ebe8aeafbae46bc5aa167b8115bc45)
1 /* $NetBSD: adadc.c,v 1.3 2018/03/16 22:10:31 macallan Exp $ */
2 
3 /*-
4  * Copyright (c) 2018 Michael Lorenz
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * a driver for Analog Devices AD7417 temperature sensors / ADCs
31  * very much macppc only for now since we need calibaration data to make sense
32  * of the ADC inputs
33  * info on how to get these from FreeBSD and Linux
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: adadc.c,v 1.3 2018/03/16 22:10:31 macallan Exp $");
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/device.h>
42 #include <sys/conf.h>
43 #include <sys/bus.h>
44 
45 #include <dev/i2c/i2cvar.h>
46 
47 #include <dev/sysmon/sysmonvar.h>
48 
49 #include <dev/ofw/openfirm.h>
50 
51 /* commands */
52 #define ADADC_TEMP	0x00	/* temperature, 16bit */
53 #define ADADC_CONFIG	0x01	/* 8bit */
54 #define ADADC_THYST	0x02	/* 16bit */
55 #define ADADC_TOTI	0x03	/* 16bit, temperature threshold */
56 #define ADADC_ADC	0x04	/* 16bit, ADC value */
57 #define ADADC_CONFIG2	0x05	/* 8bit */
58 
59 /*
60  * registers
61  * ADADC_TEMP has signed temperature in C in first byte, left aligned fraction
62  * in 2nd byte.
63  */
64 
65 #define ADADC_CFG_CHANNEL_0	0x00
66 #define ADADC_CFG_CHANNEL_1	0x20
67 #define ADADC_CFG_CHANNEL_2	0x40
68 #define ADADC_CFG_CHANNEL_3	0x60
69 #define ADADC_CFG_CHANNEL_4	0x80
70 #define ADADC_CFG_CHANNEL_MASK	0xe0
71 #define ADADC_CFG_FAULT_MASK	0x18
72 #define ADADC_CFG_OTI_POL	0x04	/* overtemp output polarity */
73 #define ADADC_CFG_INTMODE	0x02	/* interrupt mode */
74 #define ADADC_CFG_SHUTDOWN	0x01	/* shutdown mode */
75 
76 
77 struct adadc_softc {
78 	device_t	sc_dev;
79 	i2c_tag_t	sc_i2c;
80 	i2c_addr_t	sc_addr;
81 
82 	struct sysmon_envsys *sc_sme;
83 	envsys_data_t	sc_sensors[5];
84 	int		sc_nsensors;
85 	int		sc_diode_offset, sc_diode_slope;
86 };
87 
88 static int	adadc_match(device_t, cfdata_t, void *);
89 static void	adadc_attach(device_t, device_t, void *);
90 
91 static void	adadc_sensors_refresh(struct sysmon_envsys *, envsys_data_t *);
92 
93 CFATTACH_DECL_NEW(adadc, sizeof(struct adadc_softc),
94     adadc_match, adadc_attach, NULL, NULL);
95 
96 static const char * dstemp_compats[] = {
97 	"ad7417",
98 	NULL
99 };
100 
101 /* calibaration table from Darwin via Linux */
102 static int slope[5] = {0, 0, 0x0320, 0x00a0, 0x1f40};
103 
104 static int
105 adadc_match(device_t parent, cfdata_t match, void *aux)
106 {
107 	struct i2c_attach_args *ia = aux;
108 
109 	if (ia->ia_name == NULL) {
110 		/*
111 		 * XXX
112 		 * this driver is pretty much useless without OF, should
113 		 * probably remove this
114 		 */
115 		if ((ia->ia_addr & 0x2b) == 0x2b)
116 			return 1;
117 		return 0;
118 	} else {
119 		return iic_compat_match(ia, dstemp_compats);
120 	}
121 }
122 
123 static void
124 adadc_attach(device_t parent, device_t self, void *aux)
125 {
126 	struct adadc_softc *sc = device_private(self);
127 	struct i2c_attach_args *ia = aux;
128 	envsys_data_t *s;
129 	int error, ch;
130 	uint32_t eeprom[40];
131 	char loc[256];
132 	int which_cpu;
133 
134 	sc->sc_dev = self;
135 	sc->sc_i2c = ia->ia_tag;
136 	sc->sc_addr = ia->ia_addr;
137 
138 	aprint_naive("\n");
139 	aprint_normal(": AD7417\n");
140 
141 	sc->sc_sme = sysmon_envsys_create();
142 	sc->sc_sme->sme_name = device_xname(self);
143 	sc->sc_sme->sme_cookie = sc;
144 	sc->sc_sme->sme_refresh = adadc_sensors_refresh;
145 	sc->sc_nsensors = 0;
146 
147 	/*
148 	 * XXX
149 	 * without OpenFirmware telling us how to interpret the ADC inputs we
150 	 * should probably just expose the temperature and four ENVSYS_INTEGERs
151 	 */
152 	which_cpu = 0;
153 	ch = OF_child(ia->ia_cookie);
154 	while (ch != 0) {
155 		if (OF_getprop(ch, "location", loc, 32) > 0) {
156 			int reg = 0;
157 			OF_getprop(ch, "reg", &reg, sizeof(reg));
158 			s = &sc->sc_sensors[sc->sc_nsensors];
159 			/*
160 			 * this setup matches my 2x 2.5GHz PCI-X G5, Linux and
161 			 * FreeBSD hardcode these as well so we should be safe
162 			 */
163 			switch (reg) {
164 			case 0:
165 				if (strstr(loc, "CPU B") != NULL)
166 					which_cpu = 1;
167 				/* FALLTHROUGH */
168 			case 1:
169 				s->units = ENVSYS_STEMP;
170 				break;
171 			case 2:
172 			case 4:
173 				s->units = ENVSYS_SAMPS;
174 				break;
175 			case 3:
176 				s->units = ENVSYS_SVOLTS_DC;
177 				break;
178 			default:
179 				s->units = ENVSYS_INTEGER;
180 			}
181 			strncpy(s->desc, loc, sizeof(s->desc));
182 			s->private = reg;
183 			sysmon_envsys_sensor_attach(sc->sc_sme, s);
184 			sc->sc_nsensors++;
185 		}
186 		ch = OF_peer(ch);
187 	}
188 	aprint_debug_dev(self, "monitoring CPU %d\n", which_cpu);
189 	error = get_cpuid(which_cpu, (uint8_t *)eeprom);
190 	if (error >= 0) {
191 		sc->sc_diode_slope = eeprom[0x11] >> 16;
192 		sc->sc_diode_offset = (int16_t)(eeprom[0x11] & 0xffff) << 12;
193 	}
194 	sysmon_envsys_register(sc->sc_sme);
195 }
196 
197 static void
198 adadc_sensors_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
199 {
200 	struct adadc_softc *sc = sme->sme_cookie;
201 	uint8_t cmd = ADADC_CONFIG;
202 	int16_t data = 0;
203 	uint16_t rdata;
204 	uint8_t cfg;
205 	int error, ch;
206 
207 
208 	iic_acquire_bus(sc->sc_i2c, 0);
209 	if (edata->private > 0) {
210 		error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
211 		    sc->sc_addr, &cmd, 1, &cfg, 1, 0);
212 		ch = cfg >> 5;
213 		/* are we on the right channel already? */
214 		if (ch != edata->private) {
215 			/* nope */
216 			cfg &= 0x1f;
217 			cfg |= (edata->private & 7) << 5;
218 			iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP,
219 			    sc->sc_addr, &cmd, 1, &cfg, 1, 0);
220 		}
221 		cmd = ADADC_ADC;
222 		/* now read the ADC register */
223 		error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
224 		    sc->sc_addr, &cmd, 1, &rdata, 2, 0);
225 		rdata = be16toh(rdata) >> 6;
226 		if (edata->private == 1) {
227 			int temp;
228 			temp = (rdata * sc->sc_diode_slope +
229 				sc->sc_diode_offset) >> 2;
230 			/* 16.16 fixed point */
231 			edata->value_cur = (temp >> 12) * 62500 + 273150000;
232 		} else {
233 			/*
234 			 * the input is 10bit, so converting to 8.4 fixed point
235 			 * is more than enough
236 			 */
237 			int temp = rdata * slope[edata->private];
238 			edata->value_cur = (temp >> 12) * 62500;
239 		}
240 	} else {
241 		cmd = ADADC_TEMP;
242 		/* just read the temperature register */
243 		error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
244 		    sc->sc_addr, &cmd, 1, &data, 2, 0);
245 		/* 8.2 bit fixed point Celsius -> microkelvin */
246 		edata->value_cur = ((data >> 6) * 250000) + 273150000;
247 	}
248 	iic_release_bus(sc->sc_i2c, 0);
249 
250 	if (error) {
251 		edata->state = ENVSYS_SINVALID;
252 	} else {
253 		edata->state = ENVSYS_SVALID;
254 	}
255 }
256