xref: /freebsd/sys/arm/freescale/vybrid/vf_adc.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*-
2  * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 /*
28  * Vybrid Family 12-bit Analog to Digital Converter (ADC)
29  * Chapter 37, Vybrid Reference Manual, Rev. 5, 07/2013
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/bus.h>
38 #include <sys/kernel.h>
39 #include <sys/module.h>
40 #include <sys/malloc.h>
41 #include <sys/rman.h>
42 #include <sys/timeet.h>
43 #include <sys/timetc.h>
44 
45 #include <dev/ofw/openfirm.h>
46 #include <dev/ofw/ofw_bus.h>
47 #include <dev/ofw/ofw_bus_subr.h>
48 
49 #include <machine/bus.h>
50 #include <machine/cpu.h>
51 #include <machine/intr.h>
52 
53 #include <arm/freescale/vybrid/vf_common.h>
54 #include <arm/freescale/vybrid/vf_adc.h>
55 
56 #define	ADC_HC0		0x00		/* Ctrl reg for hardware triggers */
57 #define	ADC_HC1		0x04		/* Ctrl reg for hardware triggers */
58 #define	 HC_AIEN	(1 << 7)	/* Conversion Complete Int Control */
59 #define	 HC_ADCH_M	0x1f		/* Input Channel Select Mask */
60 #define	 HC_ADCH_S	0		/* Input Channel Select Shift */
61 #define	ADC_HS		0x08		/* Status register for HW triggers */
62 #define	 HS_COCO0	(1 << 0)	/* Conversion Complete Flag */
63 #define	 HS_COCO1	(1 << 1)	/* Conversion Complete Flag */
64 #define	ADC_R0		0x0C		/* Data result reg for HW triggers */
65 #define	ADC_R1		0x10		/* Data result reg for HW triggers */
66 #define	ADC_CFG		0x14		/* Configuration register */
67 #define	 CFG_OVWREN	(1 << 16)	/* Data Overwrite Enable */
68 #define	 CFG_AVGS_M	0x3		/* Hardware Average select Mask */
69 #define	 CFG_AVGS_S	14		/* Hardware Average select Shift */
70 #define	 CFG_ADTRG	(1 << 13)	/* Conversion Trigger Select */
71 #define	 CFG_REFSEL_M	0x3		/* Voltage Reference Select Mask */
72 #define	 CFG_REFSEL_S	11		/* Voltage Reference Select Shift */
73 #define	 CFG_ADHSC	(1 << 10)	/* High Speed Configuration */
74 #define	 CFG_ADSTS_M	0x3		/* Defines the sample time duration */
75 #define	 CFG_ADSTS_S	8		/* Defines the sample time duration */
76 #define	 CFG_ADLPC	(1 << 7)	/* Low-Power Configuration */
77 #define	 CFG_ADIV_M	0x3		/* Clock Divide Select */
78 #define	 CFG_ADIV_S	5		/* Clock Divide Select */
79 #define	 CFG_ADLSMP	(1 << 4)	/* Long Sample Time Configuration */
80 #define	 CFG_MODE_M	0x3		/* Conversion Mode Selection Mask */
81 #define	 CFG_MODE_S	2		/* Conversion Mode Selection Shift */
82 #define	 CFG_MODE_12	0x2		/* 12-bit mode */
83 #define	 CFG_ADICLK_M	0x3		/* Input Clock Select Mask */
84 #define	 CFG_ADICLK_S	0		/* Input Clock Select Shift */
85 #define	ADC_GC		0x18		/* General control register */
86 #define	 GC_CAL		(1 << 7)	/* Calibration */
87 #define	 GC_ADCO	(1 << 6)	/* Continuous Conversion Enable */
88 #define	 GC_AVGE	(1 << 5)	/* Hardware average enable */
89 #define	 GC_ACFE	(1 << 4)	/* Compare Function Enable */
90 #define	 GC_ACFGT	(1 << 3)	/* Compare Function Greater Than En */
91 #define	 GC_ACREN	(1 << 2)	/* Compare Function Range En */
92 #define	 GC_DMAEN	(1 << 1)	/* DMA Enable */
93 #define	 GC_ADACKEN	(1 << 0)	/* Asynchronous clock output enable */
94 #define	ADC_GS		0x1C		/* General status register */
95 #define	 GS_AWKST	(1 << 2)	/* Asynchronous wakeup int status */
96 #define	 GS_CALF	(1 << 1)	/* Calibration Failed Flag */
97 #define	 GS_ADACT	(1 << 0)	/* Conversion Active */
98 #define	ADC_CV		0x20		/* Compare value register */
99 #define	 CV_CV2_M	0xfff		/* Compare Value 2 Mask */
100 #define	 CV_CV2_S	16		/* Compare Value 2 Shift */
101 #define	 CV_CV1_M	0xfff		/* Compare Value 1 Mask */
102 #define	 CV_CV1_S	0		/* Compare Value 1 Shift */
103 #define	ADC_OFS		0x24		/* Offset correction value register */
104 #define	 OFS_SIGN	12		/* Sign bit */
105 #define	 OFS_M		0xfff		/* Offset value Mask */
106 #define	 OFS_S		0		/* Offset value Shift */
107 #define	ADC_CAL		0x28		/* Calibration value register */
108 #define	 CAL_CODE_M	0xf		/* Calibration Result Value Mask */
109 #define	 CAL_CODE_S	0		/* Calibration Result Value Shift */
110 #define	ADC_PCTL	0x30		/* Pin control register */
111 
112 struct adc_softc {
113 	struct resource		*res[2];
114 	bus_space_tag_t		bst;
115 	bus_space_handle_t	bsh;
116 	void			*ih;
117 };
118 
119 struct adc_softc *adc_sc;
120 
121 static struct resource_spec adc_spec[] = {
122 	{ SYS_RES_MEMORY,	0,	RF_ACTIVE },
123 	{ SYS_RES_IRQ,		0,	RF_ACTIVE },
124 	{ -1, 0 }
125 };
126 
127 static int
128 adc_probe(device_t dev)
129 {
130 
131 	if (!ofw_bus_status_okay(dev))
132 		return (ENXIO);
133 
134 	if (!ofw_bus_is_compatible(dev, "fsl,mvf600-adc"))
135 		return (ENXIO);
136 
137 	device_set_desc(dev, "Vybrid Family "
138 	    "12-bit Analog to Digital Converter");
139 	return (BUS_PROBE_DEFAULT);
140 }
141 
142 static void
143 adc_intr(void *arg)
144 {
145 
146 	/* Conversation complete */
147 }
148 
149 uint32_t
150 adc_read(void)
151 {
152 	struct adc_softc *sc;
153 
154 	sc = adc_sc;
155 	if (sc == NULL)
156 		return (0);
157 
158 	return (READ4(sc, ADC_R0));
159 }
160 
161 uint32_t
162 adc_enable(int channel)
163 {
164 	struct adc_softc *sc;
165 	int reg;
166 
167 	sc = adc_sc;
168 	if (sc == NULL)
169 		return (1);
170 
171 	reg = READ4(sc, ADC_HC0);
172 	reg &= ~(HC_ADCH_M << HC_ADCH_S);
173 	reg |= (channel << HC_ADCH_S);
174 	WRITE4(sc, ADC_HC0, reg);
175 
176 	return (0);
177 }
178 
179 static int
180 adc_attach(device_t dev)
181 {
182 	struct adc_softc *sc;
183 	int err;
184 	int reg;
185 
186 	sc = device_get_softc(dev);
187 
188 	if (bus_alloc_resources(dev, adc_spec, sc->res)) {
189 		device_printf(dev, "could not allocate resources\n");
190 		return (ENXIO);
191 	}
192 
193 	/* Memory interface */
194 	sc->bst = rman_get_bustag(sc->res[0]);
195 	sc->bsh = rman_get_bushandle(sc->res[0]);
196 
197 	adc_sc = sc;
198 
199 	/* Setup interrupt handler */
200 	err = bus_setup_intr(dev, sc->res[1], INTR_TYPE_BIO | INTR_MPSAFE,
201 	    NULL, adc_intr, sc, &sc->ih);
202 	if (err) {
203 		device_printf(dev, "Unable to alloc interrupt resource.\n");
204 		return (ENXIO);
205 	}
206 
207 	/* Configure 12-bit mode */
208 	reg = READ4(sc, ADC_CFG);
209 	reg &= ~(CFG_MODE_M << CFG_MODE_S);
210 	reg |= (CFG_MODE_12 << CFG_MODE_S); /* 12bit */
211 	WRITE4(sc, ADC_CFG, reg);
212 
213 	/* Configure for continuous conversion */
214 	reg = READ4(sc, ADC_GC);
215 	reg |= (GC_ADCO | GC_AVGE);
216 	WRITE4(sc, ADC_GC, reg);
217 
218 	/* Disable interrupts */
219 	reg = READ4(sc, ADC_HC0);
220 	reg &= HC_AIEN;
221 	WRITE4(sc, ADC_HC0, reg);
222 
223 	return (0);
224 }
225 
226 static device_method_t adc_methods[] = {
227 	DEVMETHOD(device_probe,		adc_probe),
228 	DEVMETHOD(device_attach,	adc_attach),
229 	{ 0, 0 }
230 };
231 
232 static driver_t adc_driver = {
233 	"adc",
234 	adc_methods,
235 	sizeof(struct adc_softc),
236 };
237 
238 DRIVER_MODULE(adc, simplebus, adc_driver, 0, 0);
239