adadc.c revision 1.8
1/* $NetBSD: adadc.c,v 1.8 2021/01/17 21:42:35 thorpej 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 1.8 2021/01/17 21:42:35 thorpej 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
77struct 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
88static int	adadc_match(device_t, cfdata_t, void *);
89static void	adadc_attach(device_t, device_t, void *);
90
91static void	adadc_sensors_refresh(struct sysmon_envsys *, envsys_data_t *);
92
93CFATTACH_DECL_NEW(adadc, sizeof(struct adadc_softc),
94    adadc_match, adadc_attach, NULL, NULL);
95
96static const struct device_compatible_entry compat_data[] = {
97	{ .compat = "ad7417" },
98
99	{ 0 }
100};
101
102/* calibaration table from Darwin via Linux */
103static int slope[5] = {0, 0, 0x0320, 0x00a0, 0x1f40};
104
105static int
106adadc_match(device_t parent, cfdata_t match, void *aux)
107{
108	struct i2c_attach_args *ia = aux;
109	int match_result;
110
111	if (iic_use_direct_match(ia, match, compat_data, &match_result))
112		return match_result;
113
114	/*
115	 * XXX
116	 * this driver is pretty much useless without OF, should
117	 * probably remove this
118	 */
119	if ((ia->ia_addr & 0x2b) == 0x2b)
120		return I2C_MATCH_ADDRESS_ONLY;
121
122	return 0;
123}
124
125static void
126adadc_attach(device_t parent, device_t self, void *aux)
127{
128	struct adadc_softc *sc = device_private(self);
129	struct i2c_attach_args *ia = aux;
130	envsys_data_t *s;
131	int error, ch;
132	uint32_t eeprom[40];
133	char loc[256];
134	int which_cpu;
135
136	sc->sc_dev = self;
137	sc->sc_i2c = ia->ia_tag;
138	sc->sc_addr = ia->ia_addr;
139
140	aprint_naive("\n");
141	aprint_normal(": AD7417\n");
142
143	sc->sc_sme = sysmon_envsys_create();
144	sc->sc_sme->sme_name = device_xname(self);
145	sc->sc_sme->sme_cookie = sc;
146	sc->sc_sme->sme_refresh = adadc_sensors_refresh;
147	sc->sc_nsensors = 0;
148
149	/*
150	 * XXX
151	 * without OpenFirmware telling us how to interpret the ADC inputs we
152	 * should probably just expose the temperature and four ENVSYS_INTEGERs
153	 */
154	which_cpu = 0;
155	ch = OF_child(ia->ia_cookie);
156	while (ch != 0) {
157		if (OF_getprop(ch, "location", loc, 32) > 0) {
158			int reg = 0;
159			OF_getprop(ch, "reg", &reg, sizeof(reg));
160			s = &sc->sc_sensors[sc->sc_nsensors];
161			s->state = ENVSYS_SINVALID;
162			/*
163			 * this setup matches my 2x 2.5GHz PCI-X G5, Linux and
164			 * FreeBSD hardcode these as well so we should be safe
165			 */
166			switch (reg) {
167			case 0:
168				if (strstr(loc, "CPU B") != NULL)
169					which_cpu = 1;
170				/* FALLTHROUGH */
171			case 1:
172				s->units = ENVSYS_STEMP;
173				break;
174			case 2:
175			case 4:
176				s->units = ENVSYS_SAMPS;
177				break;
178			case 3:
179				s->units = ENVSYS_SVOLTS_DC;
180				break;
181			default:
182				s->units = ENVSYS_INTEGER;
183			}
184			strncpy(s->desc, loc, sizeof(s->desc));
185			s->private = reg;
186			sysmon_envsys_sensor_attach(sc->sc_sme, s);
187			sc->sc_nsensors++;
188		}
189		ch = OF_peer(ch);
190	}
191	aprint_debug_dev(self, "monitoring CPU %d\n", which_cpu);
192	error = get_cpuid(which_cpu, (uint8_t *)eeprom);
193	if (error >= 0) {
194		sc->sc_diode_slope = eeprom[0x11] >> 16;
195		sc->sc_diode_offset = (int16_t)(eeprom[0x11] & 0xffff) << 12;
196	}
197	sysmon_envsys_register(sc->sc_sme);
198}
199
200static void
201adadc_sensors_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
202{
203	struct adadc_softc *sc = sme->sme_cookie;
204	uint8_t cmd = ADADC_CONFIG;
205	int16_t data = 0;
206	uint16_t rdata;
207	uint8_t cfg;
208	int error, ch;
209
210
211	iic_acquire_bus(sc->sc_i2c, 0);
212	if (edata->private > 0) {
213		error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
214		    sc->sc_addr, &cmd, 1, &cfg, 1, 0);
215		ch = cfg >> 5;
216		/* are we on the right channel already? */
217		if (ch != edata->private) {
218			/* nope */
219			cfg &= 0x1f;
220			cfg |= (edata->private & 7) << 5;
221			iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP,
222			    sc->sc_addr, &cmd, 1, &cfg, 1, 0);
223		}
224		cmd = ADADC_ADC;
225		/* now read the ADC register */
226		error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
227		    sc->sc_addr, &cmd, 1, &rdata, 2, 0);
228		rdata = be16toh(rdata) >> 6;
229		if (edata->private == 1) {
230			int temp;
231			temp = (rdata * sc->sc_diode_slope +
232				sc->sc_diode_offset) >> 2;
233			/* 16.16 fixed point */
234			edata->value_cur = (temp >> 12) * 62500 + 273150000;
235		} else {
236			/*
237			 * the input is 10bit, so converting to 8.4 fixed point
238			 * is more than enough
239			 */
240			int temp = rdata * slope[edata->private];
241			edata->value_cur = (temp >> 12) * 62500;
242		}
243	} else {
244		cmd = ADADC_TEMP;
245		/* just read the temperature register */
246		error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP,
247		    sc->sc_addr, &cmd, 1, &data, 2, 0);
248		/* 8.2 bit fixed point Celsius -> microkelvin */
249		edata->value_cur = ((data >> 6) * 250000) + 273150000;
250	}
251	iic_release_bus(sc->sc_i2c, 0);
252
253	if (error) {
254		edata->state = ENVSYS_SINVALID;
255	} else {
256		edata->state = ENVSYS_SVALID;
257	}
258}
259