1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * mpc624.c |
4 | * Hardware driver for a Micro/sys inc. MPC-624 PC/104 board |
5 | * |
6 | * COMEDI - Linux Control and Measurement Device Interface |
7 | * Copyright (C) 2000 David A. Schleef <ds@schleef.org> |
8 | */ |
9 | |
10 | /* |
11 | * Driver: mpc624 |
12 | * Description: Micro/sys MPC-624 PC/104 board |
13 | * Devices: [Micro/sys] MPC-624 (mpc624) |
14 | * Author: Stanislaw Raczynski <sraczynski@op.pl> |
15 | * Updated: Thu, 15 Sep 2005 12:01:18 +0200 |
16 | * Status: working |
17 | * |
18 | * The Micro/sys MPC-624 board is based on the LTC2440 24-bit sigma-delta |
19 | * ADC chip. |
20 | * |
21 | * Subdevices supported by the driver: |
22 | * - Analog In: supported |
23 | * - Digital I/O: not supported |
24 | * - LEDs: not supported |
25 | * - EEPROM: not supported |
26 | * |
27 | * Configuration Options: |
28 | * [0] - I/O base address |
29 | * [1] - conversion rate |
30 | * Conversion rate RMS noise Effective Number Of Bits |
31 | * 0 3.52kHz 23uV 17 |
32 | * 1 1.76kHz 3.5uV 20 |
33 | * 2 880Hz 2uV 21.3 |
34 | * 3 440Hz 1.4uV 21.8 |
35 | * 4 220Hz 1uV 22.4 |
36 | * 5 110Hz 750uV 22.9 |
37 | * 6 55Hz 510nV 23.4 |
38 | * 7 27.5Hz 375nV 24 |
39 | * 8 13.75Hz 250nV 24.4 |
40 | * 9 6.875Hz 200nV 24.6 |
41 | * [2] - voltage range |
42 | * 0 -1.01V .. +1.01V |
43 | * 1 -10.1V .. +10.1V |
44 | */ |
45 | |
46 | #include <linux/module.h> |
47 | #include <linux/comedi/comedidev.h> |
48 | #include <linux/delay.h> |
49 | |
50 | /* Offsets of different ports */ |
51 | #define MPC624_MASTER_CONTROL 0 /* not used */ |
52 | #define MPC624_GNMUXCH 1 /* Gain, Mux, Channel of ADC */ |
53 | #define MPC624_ADC 2 /* read/write to/from ADC */ |
54 | #define MPC624_EE 3 /* read/write to/from serial EEPROM via I2C */ |
55 | #define MPC624_LEDS 4 /* write to LEDs */ |
56 | #define MPC624_DIO 5 /* read/write to/from digital I/O ports */ |
57 | #define MPC624_IRQ_MASK 6 /* IRQ masking enable/disable */ |
58 | |
59 | /* Register bits' names */ |
60 | #define MPC624_ADBUSY BIT(5) |
61 | #define MPC624_ADSDO BIT(4) |
62 | #define MPC624_ADFO BIT(3) |
63 | #define MPC624_ADCS BIT(2) |
64 | #define MPC624_ADSCK BIT(1) |
65 | #define MPC624_ADSDI BIT(0) |
66 | |
67 | /* 32-bit output value bits' names */ |
68 | #define MPC624_EOC_BIT BIT(31) |
69 | #define MPC624_DMY_BIT BIT(30) |
70 | #define MPC624_SGN_BIT BIT(29) |
71 | |
72 | /* SDI Speed/Resolution Programming bits */ |
73 | #define MPC624_OSR(x) (((x) & 0x1f) << 27) |
74 | #define MPC624_SPEED_3_52_KHZ MPC624_OSR(0x11) |
75 | #define MPC624_SPEED_1_76_KHZ MPC624_OSR(0x12) |
76 | #define MPC624_SPEED_880_HZ MPC624_OSR(0x13) |
77 | #define MPC624_SPEED_440_HZ MPC624_OSR(0x14) |
78 | #define MPC624_SPEED_220_HZ MPC624_OSR(0x15) |
79 | #define MPC624_SPEED_110_HZ MPC624_OSR(0x16) |
80 | #define MPC624_SPEED_55_HZ MPC624_OSR(0x17) |
81 | #define MPC624_SPEED_27_5_HZ MPC624_OSR(0x18) |
82 | #define MPC624_SPEED_13_75_HZ MPC624_OSR(0x19) |
83 | #define MPC624_SPEED_6_875_HZ MPC624_OSR(0x1f) |
84 | |
85 | struct mpc624_private { |
86 | unsigned int ai_speed; |
87 | }; |
88 | |
89 | /* -------------------------------------------------------------------------- */ |
90 | static const struct comedi_lrange range_mpc624_bipolar1 = { |
91 | 1, |
92 | { |
93 | /* BIP_RANGE(1.01) this is correct, */ |
94 | /* but my MPC-624 actually seems to have a range of 2.02 */ |
95 | BIP_RANGE(2.02) |
96 | } |
97 | }; |
98 | |
99 | static const struct comedi_lrange range_mpc624_bipolar10 = { |
100 | 1, |
101 | { |
102 | /* BIP_RANGE(10.1) this is correct, */ |
103 | /* but my MPC-624 actually seems to have a range of 20.2 */ |
104 | BIP_RANGE(20.2) |
105 | } |
106 | }; |
107 | |
108 | static unsigned int mpc624_ai_get_sample(struct comedi_device *dev, |
109 | struct comedi_subdevice *s) |
110 | { |
111 | struct mpc624_private *devpriv = dev->private; |
112 | unsigned int data_out = devpriv->ai_speed; |
113 | unsigned int data_in = 0; |
114 | unsigned int bit; |
115 | int i; |
116 | |
117 | /* Start reading data */ |
118 | udelay(1); |
119 | for (i = 0; i < 32; i++) { |
120 | /* Set the clock low */ |
121 | outb(value: 0, port: dev->iobase + MPC624_ADC); |
122 | udelay(1); |
123 | |
124 | /* Set the ADSDI line for the next bit (send to MPC624) */ |
125 | bit = (data_out & BIT(31)) ? MPC624_ADSDI : 0; |
126 | outb(value: bit, port: dev->iobase + MPC624_ADC); |
127 | udelay(1); |
128 | |
129 | /* Set the clock high */ |
130 | outb(MPC624_ADSCK | bit, port: dev->iobase + MPC624_ADC); |
131 | udelay(1); |
132 | |
133 | /* Read ADSDO on high clock (receive from MPC624) */ |
134 | data_in <<= 1; |
135 | data_in |= (inb(port: dev->iobase + MPC624_ADC) & MPC624_ADSDO) >> 4; |
136 | udelay(1); |
137 | |
138 | data_out <<= 1; |
139 | } |
140 | |
141 | /* |
142 | * Received 32-bit long value consist of: |
143 | * 31: EOC - (End Of Transmission) bit - should be 0 |
144 | * 30: DMY - (Dummy) bit - should be 0 |
145 | * 29: SIG - (Sign) bit - 1 if positive, 0 if negative |
146 | * 28: MSB - (Most Significant Bit) - the first bit of the |
147 | * conversion result |
148 | * .... |
149 | * 05: LSB - (Least Significant Bit)- the last bit of the |
150 | * conversion result |
151 | * 04-00: sub-LSB - sub-LSBs are basically noise, but when |
152 | * averaged properly, they can increase |
153 | * conversion precision up to 29 bits; |
154 | * they can be discarded without loss of |
155 | * resolution. |
156 | */ |
157 | if (data_in & MPC624_EOC_BIT) |
158 | dev_dbg(dev->class_dev, "EOC bit is set!" ); |
159 | if (data_in & MPC624_DMY_BIT) |
160 | dev_dbg(dev->class_dev, "DMY bit is set!" ); |
161 | |
162 | if (data_in & MPC624_SGN_BIT) { |
163 | /* |
164 | * Voltage is positive |
165 | * |
166 | * comedi operates on unsigned numbers, so mask off EOC |
167 | * and DMY and don't clear the SGN bit |
168 | */ |
169 | data_in &= 0x3fffffff; |
170 | } else { |
171 | /* |
172 | * The voltage is negative |
173 | * |
174 | * data_in contains a number in 30-bit two's complement |
175 | * code and we must deal with it |
176 | */ |
177 | data_in |= MPC624_SGN_BIT; |
178 | data_in = ~data_in; |
179 | data_in += 1; |
180 | /* clear EOC and DMY bits */ |
181 | data_in &= ~(MPC624_EOC_BIT | MPC624_DMY_BIT); |
182 | data_in = 0x20000000 - data_in; |
183 | } |
184 | return data_in; |
185 | } |
186 | |
187 | static int mpc624_ai_eoc(struct comedi_device *dev, |
188 | struct comedi_subdevice *s, |
189 | struct comedi_insn *insn, |
190 | unsigned long context) |
191 | { |
192 | unsigned char status; |
193 | |
194 | status = inb(port: dev->iobase + MPC624_ADC); |
195 | if ((status & MPC624_ADBUSY) == 0) |
196 | return 0; |
197 | return -EBUSY; |
198 | } |
199 | |
200 | static int mpc624_ai_insn_read(struct comedi_device *dev, |
201 | struct comedi_subdevice *s, |
202 | struct comedi_insn *insn, |
203 | unsigned int *data) |
204 | { |
205 | int ret; |
206 | int i; |
207 | |
208 | /* |
209 | * WARNING: |
210 | * We always write 0 to GNSWA bit, so the channel range is +-/10.1Vdc |
211 | */ |
212 | outb(value: insn->chanspec, port: dev->iobase + MPC624_GNMUXCH); |
213 | |
214 | for (i = 0; i < insn->n; i++) { |
215 | /* Trigger the conversion */ |
216 | outb(MPC624_ADSCK, port: dev->iobase + MPC624_ADC); |
217 | udelay(1); |
218 | outb(MPC624_ADCS | MPC624_ADSCK, port: dev->iobase + MPC624_ADC); |
219 | udelay(1); |
220 | outb(value: 0, port: dev->iobase + MPC624_ADC); |
221 | udelay(1); |
222 | |
223 | /* Wait for the conversion to end */ |
224 | ret = comedi_timeout(dev, s, insn, cb: mpc624_ai_eoc, context: 0); |
225 | if (ret) |
226 | return ret; |
227 | |
228 | data[i] = mpc624_ai_get_sample(dev, s); |
229 | } |
230 | |
231 | return insn->n; |
232 | } |
233 | |
234 | static int mpc624_attach(struct comedi_device *dev, struct comedi_devconfig *it) |
235 | { |
236 | struct mpc624_private *devpriv; |
237 | struct comedi_subdevice *s; |
238 | int ret; |
239 | |
240 | ret = comedi_request_region(dev, start: it->options[0], len: 0x10); |
241 | if (ret) |
242 | return ret; |
243 | |
244 | devpriv = comedi_alloc_devpriv(dev, size: sizeof(*devpriv)); |
245 | if (!devpriv) |
246 | return -ENOMEM; |
247 | |
248 | switch (it->options[1]) { |
249 | case 0: |
250 | devpriv->ai_speed = MPC624_SPEED_3_52_KHZ; |
251 | break; |
252 | case 1: |
253 | devpriv->ai_speed = MPC624_SPEED_1_76_KHZ; |
254 | break; |
255 | case 2: |
256 | devpriv->ai_speed = MPC624_SPEED_880_HZ; |
257 | break; |
258 | case 3: |
259 | devpriv->ai_speed = MPC624_SPEED_440_HZ; |
260 | break; |
261 | case 4: |
262 | devpriv->ai_speed = MPC624_SPEED_220_HZ; |
263 | break; |
264 | case 5: |
265 | devpriv->ai_speed = MPC624_SPEED_110_HZ; |
266 | break; |
267 | case 6: |
268 | devpriv->ai_speed = MPC624_SPEED_55_HZ; |
269 | break; |
270 | case 7: |
271 | devpriv->ai_speed = MPC624_SPEED_27_5_HZ; |
272 | break; |
273 | case 8: |
274 | devpriv->ai_speed = MPC624_SPEED_13_75_HZ; |
275 | break; |
276 | case 9: |
277 | devpriv->ai_speed = MPC624_SPEED_6_875_HZ; |
278 | break; |
279 | default: |
280 | devpriv->ai_speed = MPC624_SPEED_3_52_KHZ; |
281 | } |
282 | |
283 | ret = comedi_alloc_subdevices(dev, num_subdevices: 1); |
284 | if (ret) |
285 | return ret; |
286 | |
287 | /* Analog Input subdevice */ |
288 | s = &dev->subdevices[0]; |
289 | s->type = COMEDI_SUBD_AI; |
290 | s->subdev_flags = SDF_READABLE | SDF_DIFF; |
291 | s->n_chan = 4; |
292 | s->maxdata = 0x3fffffff; |
293 | s->range_table = (it->options[1] == 0) ? &range_mpc624_bipolar1 |
294 | : &range_mpc624_bipolar10; |
295 | s->insn_read = mpc624_ai_insn_read; |
296 | |
297 | return 0; |
298 | } |
299 | |
300 | static struct comedi_driver mpc624_driver = { |
301 | .driver_name = "mpc624" , |
302 | .module = THIS_MODULE, |
303 | .attach = mpc624_attach, |
304 | .detach = comedi_legacy_detach, |
305 | }; |
306 | module_comedi_driver(mpc624_driver); |
307 | |
308 | MODULE_AUTHOR("Comedi https://www.comedi.org" ); |
309 | MODULE_DESCRIPTION("Comedi driver for Micro/sys MPC-624 PC/104 board" ); |
310 | MODULE_LICENSE("GPL" ); |
311 | |