Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* NXP PCF50633 ADC Driver
3 *
4 * (C) 2006-2008 by Openmoko, Inc.
5 * Author: Balaji Rao <balajirrao@openmoko.org>
6 * All rights reserved.
7 *
8 * Broken down from monstrous PCF50633 driver mainly by
9 * Harald Welte, Andy Green and Werner Almesberger
10 *
11 * NOTE: This driver does not yet support subtractive ADC mode, which means
12 * you can do only one measurement per read request.
13 */
14
15#include <linux/kernel.h>
16#include <linux/slab.h>
17#include <linux/module.h>
18#include <linux/device.h>
19#include <linux/platform_device.h>
20#include <linux/completion.h>
21
22#include <linux/mfd/pcf50633/core.h>
23#include <linux/mfd/pcf50633/adc.h>
24
25struct pcf50633_adc_request {
26 int mux;
27 int avg;
28 void (*callback)(struct pcf50633 *, void *, int);
29 void *callback_param;
30};
31
32struct pcf50633_adc_sync_request {
33 int result;
34 struct completion completion;
35};
36
37#define PCF50633_MAX_ADC_FIFO_DEPTH 8
38
39struct pcf50633_adc {
40 struct pcf50633 *pcf;
41
42 /* Private stuff */
43 struct pcf50633_adc_request *queue[PCF50633_MAX_ADC_FIFO_DEPTH];
44 int queue_head;
45 int queue_tail;
46 struct mutex queue_mutex;
47};
48
49static inline struct pcf50633_adc *__to_adc(struct pcf50633 *pcf)
50{
51 return platform_get_drvdata(pcf->adc_pdev);
52}
53
54static void adc_setup(struct pcf50633 *pcf, int channel, int avg)
55{
56 channel &= PCF50633_ADCC1_ADCMUX_MASK;
57
58 /* kill ratiometric, but enable ACCSW biasing */
59 pcf50633_reg_write(pcf, PCF50633_REG_ADCC2, 0x00);
60 pcf50633_reg_write(pcf, PCF50633_REG_ADCC3, 0x01);
61
62 /* start ADC conversion on selected channel */
63 pcf50633_reg_write(pcf, PCF50633_REG_ADCC1, channel | avg |
64 PCF50633_ADCC1_ADCSTART | PCF50633_ADCC1_RES_10BIT);
65}
66
67static void trigger_next_adc_job_if_any(struct pcf50633 *pcf)
68{
69 struct pcf50633_adc *adc = __to_adc(pcf);
70 int head;
71
72 head = adc->queue_head;
73
74 if (!adc->queue[head])
75 return;
76
77 adc_setup(pcf, adc->queue[head]->mux, adc->queue[head]->avg);
78}
79
80static int
81adc_enqueue_request(struct pcf50633 *pcf, struct pcf50633_adc_request *req)
82{
83 struct pcf50633_adc *adc = __to_adc(pcf);
84 int head, tail;
85
86 mutex_lock(&adc->queue_mutex);
87
88 head = adc->queue_head;
89 tail = adc->queue_tail;
90
91 if (adc->queue[tail]) {
92 mutex_unlock(&adc->queue_mutex);
93 dev_err(pcf->dev, "ADC queue is full, dropping request\n");
94 return -EBUSY;
95 }
96
97 adc->queue[tail] = req;
98 if (head == tail)
99 trigger_next_adc_job_if_any(pcf);
100 adc->queue_tail = (tail + 1) & (PCF50633_MAX_ADC_FIFO_DEPTH - 1);
101
102 mutex_unlock(&adc->queue_mutex);
103
104 return 0;
105}
106
107static void pcf50633_adc_sync_read_callback(struct pcf50633 *pcf, void *param,
108 int result)
109{
110 struct pcf50633_adc_sync_request *req = param;
111
112 req->result = result;
113 complete(&req->completion);
114}
115
116int pcf50633_adc_sync_read(struct pcf50633 *pcf, int mux, int avg)
117{
118 struct pcf50633_adc_sync_request req;
119 int ret;
120
121 init_completion(&req.completion);
122
123 ret = pcf50633_adc_async_read(pcf, mux, avg,
124 pcf50633_adc_sync_read_callback, &req);
125 if (ret)
126 return ret;
127
128 wait_for_completion(&req.completion);
129
130 return req.result;
131}
132EXPORT_SYMBOL_GPL(pcf50633_adc_sync_read);
133
134int pcf50633_adc_async_read(struct pcf50633 *pcf, int mux, int avg,
135 void (*callback)(struct pcf50633 *, void *, int),
136 void *callback_param)
137{
138 struct pcf50633_adc_request *req;
139 int ret;
140
141 /* req is freed when the result is ready, in interrupt handler */
142 req = kmalloc(sizeof(*req), GFP_KERNEL);
143 if (!req)
144 return -ENOMEM;
145
146 req->mux = mux;
147 req->avg = avg;
148 req->callback = callback;
149 req->callback_param = callback_param;
150
151 ret = adc_enqueue_request(pcf, req);
152 if (ret)
153 kfree(req);
154
155 return ret;
156}
157EXPORT_SYMBOL_GPL(pcf50633_adc_async_read);
158
159static int adc_result(struct pcf50633 *pcf)
160{
161 u8 adcs1, adcs3;
162 u16 result;
163
164 adcs1 = pcf50633_reg_read(pcf, PCF50633_REG_ADCS1);
165 adcs3 = pcf50633_reg_read(pcf, PCF50633_REG_ADCS3);
166 result = (adcs1 << 2) | (adcs3 & PCF50633_ADCS3_ADCDAT1L_MASK);
167
168 dev_dbg(pcf->dev, "adc result = %d\n", result);
169
170 return result;
171}
172
173static void pcf50633_adc_irq(int irq, void *data)
174{
175 struct pcf50633_adc *adc = data;
176 struct pcf50633 *pcf = adc->pcf;
177 struct pcf50633_adc_request *req;
178 int head, res;
179
180 mutex_lock(&adc->queue_mutex);
181 head = adc->queue_head;
182
183 req = adc->queue[head];
184 if (WARN_ON(!req)) {
185 dev_err(pcf->dev, "pcf50633-adc irq: ADC queue empty!\n");
186 mutex_unlock(&adc->queue_mutex);
187 return;
188 }
189 adc->queue[head] = NULL;
190 adc->queue_head = (head + 1) &
191 (PCF50633_MAX_ADC_FIFO_DEPTH - 1);
192
193 res = adc_result(pcf);
194 trigger_next_adc_job_if_any(pcf);
195
196 mutex_unlock(&adc->queue_mutex);
197
198 req->callback(pcf, req->callback_param, res);
199 kfree(req);
200}
201
202static int pcf50633_adc_probe(struct platform_device *pdev)
203{
204 struct pcf50633_adc *adc;
205
206 adc = devm_kzalloc(&pdev->dev, sizeof(*adc), GFP_KERNEL);
207 if (!adc)
208 return -ENOMEM;
209
210 adc->pcf = dev_to_pcf50633(pdev->dev.parent);
211 platform_set_drvdata(pdev, adc);
212
213 pcf50633_register_irq(adc->pcf, PCF50633_IRQ_ADCRDY,
214 pcf50633_adc_irq, adc);
215
216 mutex_init(&adc->queue_mutex);
217
218 return 0;
219}
220
221static void pcf50633_adc_remove(struct platform_device *pdev)
222{
223 struct pcf50633_adc *adc = platform_get_drvdata(pdev);
224 int i, head;
225
226 pcf50633_free_irq(adc->pcf, PCF50633_IRQ_ADCRDY);
227
228 mutex_lock(&adc->queue_mutex);
229 head = adc->queue_head;
230
231 if (WARN_ON(adc->queue[head]))
232 dev_err(adc->pcf->dev,
233 "adc driver removed with request pending\n");
234
235 for (i = 0; i < PCF50633_MAX_ADC_FIFO_DEPTH; i++)
236 kfree(adc->queue[i]);
237
238 mutex_unlock(&adc->queue_mutex);
239}
240
241static struct platform_driver pcf50633_adc_driver = {
242 .driver = {
243 .name = "pcf50633-adc",
244 },
245 .probe = pcf50633_adc_probe,
246 .remove_new = pcf50633_adc_remove,
247};
248
249module_platform_driver(pcf50633_adc_driver);
250
251MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
252MODULE_DESCRIPTION("PCF50633 adc driver");
253MODULE_LICENSE("GPL");
254MODULE_ALIAS("platform:pcf50633-adc");
255
1/* NXP PCF50633 ADC Driver
2 *
3 * (C) 2006-2008 by Openmoko, Inc.
4 * Author: Balaji Rao <balajirrao@openmoko.org>
5 * All rights reserved.
6 *
7 * Broken down from monstrous PCF50633 driver mainly by
8 * Harald Welte, Andy Green and Werner Almesberger
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 *
15 * NOTE: This driver does not yet support subtractive ADC mode, which means
16 * you can do only one measurement per read request.
17 */
18
19#include <linux/kernel.h>
20#include <linux/slab.h>
21#include <linux/module.h>
22#include <linux/init.h>
23#include <linux/device.h>
24#include <linux/platform_device.h>
25#include <linux/completion.h>
26
27#include <linux/mfd/pcf50633/core.h>
28#include <linux/mfd/pcf50633/adc.h>
29
30struct pcf50633_adc_request {
31 int mux;
32 int avg;
33 void (*callback)(struct pcf50633 *, void *, int);
34 void *callback_param;
35};
36
37struct pcf50633_adc_sync_request {
38 int result;
39 struct completion completion;
40};
41
42#define PCF50633_MAX_ADC_FIFO_DEPTH 8
43
44struct pcf50633_adc {
45 struct pcf50633 *pcf;
46
47 /* Private stuff */
48 struct pcf50633_adc_request *queue[PCF50633_MAX_ADC_FIFO_DEPTH];
49 int queue_head;
50 int queue_tail;
51 struct mutex queue_mutex;
52};
53
54static inline struct pcf50633_adc *__to_adc(struct pcf50633 *pcf)
55{
56 return platform_get_drvdata(pcf->adc_pdev);
57}
58
59static void adc_setup(struct pcf50633 *pcf, int channel, int avg)
60{
61 channel &= PCF50633_ADCC1_ADCMUX_MASK;
62
63 /* kill ratiometric, but enable ACCSW biasing */
64 pcf50633_reg_write(pcf, PCF50633_REG_ADCC2, 0x00);
65 pcf50633_reg_write(pcf, PCF50633_REG_ADCC3, 0x01);
66
67 /* start ADC conversion on selected channel */
68 pcf50633_reg_write(pcf, PCF50633_REG_ADCC1, channel | avg |
69 PCF50633_ADCC1_ADCSTART | PCF50633_ADCC1_RES_10BIT);
70}
71
72static void trigger_next_adc_job_if_any(struct pcf50633 *pcf)
73{
74 struct pcf50633_adc *adc = __to_adc(pcf);
75 int head;
76
77 head = adc->queue_head;
78
79 if (!adc->queue[head])
80 return;
81
82 adc_setup(pcf, adc->queue[head]->mux, adc->queue[head]->avg);
83}
84
85static int
86adc_enqueue_request(struct pcf50633 *pcf, struct pcf50633_adc_request *req)
87{
88 struct pcf50633_adc *adc = __to_adc(pcf);
89 int head, tail;
90
91 mutex_lock(&adc->queue_mutex);
92
93 head = adc->queue_head;
94 tail = adc->queue_tail;
95
96 if (adc->queue[tail]) {
97 mutex_unlock(&adc->queue_mutex);
98 dev_err(pcf->dev, "ADC queue is full, dropping request\n");
99 return -EBUSY;
100 }
101
102 adc->queue[tail] = req;
103 if (head == tail)
104 trigger_next_adc_job_if_any(pcf);
105 adc->queue_tail = (tail + 1) & (PCF50633_MAX_ADC_FIFO_DEPTH - 1);
106
107 mutex_unlock(&adc->queue_mutex);
108
109 return 0;
110}
111
112static void pcf50633_adc_sync_read_callback(struct pcf50633 *pcf, void *param,
113 int result)
114{
115 struct pcf50633_adc_sync_request *req = param;
116
117 req->result = result;
118 complete(&req->completion);
119}
120
121int pcf50633_adc_sync_read(struct pcf50633 *pcf, int mux, int avg)
122{
123 struct pcf50633_adc_sync_request req;
124 int ret;
125
126 init_completion(&req.completion);
127
128 ret = pcf50633_adc_async_read(pcf, mux, avg,
129 pcf50633_adc_sync_read_callback, &req);
130 if (ret)
131 return ret;
132
133 wait_for_completion(&req.completion);
134
135 return req.result;
136}
137EXPORT_SYMBOL_GPL(pcf50633_adc_sync_read);
138
139int pcf50633_adc_async_read(struct pcf50633 *pcf, int mux, int avg,
140 void (*callback)(struct pcf50633 *, void *, int),
141 void *callback_param)
142{
143 struct pcf50633_adc_request *req;
144
145 /* req is freed when the result is ready, in interrupt handler */
146 req = kmalloc(sizeof(*req), GFP_KERNEL);
147 if (!req)
148 return -ENOMEM;
149
150 req->mux = mux;
151 req->avg = avg;
152 req->callback = callback;
153 req->callback_param = callback_param;
154
155 return adc_enqueue_request(pcf, req);
156}
157EXPORT_SYMBOL_GPL(pcf50633_adc_async_read);
158
159static int adc_result(struct pcf50633 *pcf)
160{
161 u8 adcs1, adcs3;
162 u16 result;
163
164 adcs1 = pcf50633_reg_read(pcf, PCF50633_REG_ADCS1);
165 adcs3 = pcf50633_reg_read(pcf, PCF50633_REG_ADCS3);
166 result = (adcs1 << 2) | (adcs3 & PCF50633_ADCS3_ADCDAT1L_MASK);
167
168 dev_dbg(pcf->dev, "adc result = %d\n", result);
169
170 return result;
171}
172
173static void pcf50633_adc_irq(int irq, void *data)
174{
175 struct pcf50633_adc *adc = data;
176 struct pcf50633 *pcf = adc->pcf;
177 struct pcf50633_adc_request *req;
178 int head, res;
179
180 mutex_lock(&adc->queue_mutex);
181 head = adc->queue_head;
182
183 req = adc->queue[head];
184 if (WARN_ON(!req)) {
185 dev_err(pcf->dev, "pcf50633-adc irq: ADC queue empty!\n");
186 mutex_unlock(&adc->queue_mutex);
187 return;
188 }
189 adc->queue[head] = NULL;
190 adc->queue_head = (head + 1) &
191 (PCF50633_MAX_ADC_FIFO_DEPTH - 1);
192
193 res = adc_result(pcf);
194 trigger_next_adc_job_if_any(pcf);
195
196 mutex_unlock(&adc->queue_mutex);
197
198 req->callback(pcf, req->callback_param, res);
199 kfree(req);
200}
201
202static int __devinit pcf50633_adc_probe(struct platform_device *pdev)
203{
204 struct pcf50633_adc *adc;
205
206 adc = kzalloc(sizeof(*adc), GFP_KERNEL);
207 if (!adc)
208 return -ENOMEM;
209
210 adc->pcf = dev_to_pcf50633(pdev->dev.parent);
211 platform_set_drvdata(pdev, adc);
212
213 pcf50633_register_irq(adc->pcf, PCF50633_IRQ_ADCRDY,
214 pcf50633_adc_irq, adc);
215
216 mutex_init(&adc->queue_mutex);
217
218 return 0;
219}
220
221static int __devexit pcf50633_adc_remove(struct platform_device *pdev)
222{
223 struct pcf50633_adc *adc = platform_get_drvdata(pdev);
224 int i, head;
225
226 pcf50633_free_irq(adc->pcf, PCF50633_IRQ_ADCRDY);
227
228 mutex_lock(&adc->queue_mutex);
229 head = adc->queue_head;
230
231 if (WARN_ON(adc->queue[head]))
232 dev_err(adc->pcf->dev,
233 "adc driver removed with request pending\n");
234
235 for (i = 0; i < PCF50633_MAX_ADC_FIFO_DEPTH; i++)
236 kfree(adc->queue[i]);
237
238 mutex_unlock(&adc->queue_mutex);
239 kfree(adc);
240
241 return 0;
242}
243
244static struct platform_driver pcf50633_adc_driver = {
245 .driver = {
246 .name = "pcf50633-adc",
247 },
248 .probe = pcf50633_adc_probe,
249 .remove = __devexit_p(pcf50633_adc_remove),
250};
251
252static int __init pcf50633_adc_init(void)
253{
254 return platform_driver_register(&pcf50633_adc_driver);
255}
256module_init(pcf50633_adc_init);
257
258static void __exit pcf50633_adc_exit(void)
259{
260 platform_driver_unregister(&pcf50633_adc_driver);
261}
262module_exit(pcf50633_adc_exit);
263
264MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
265MODULE_DESCRIPTION("PCF50633 adc driver");
266MODULE_LICENSE("GPL");
267MODULE_ALIAS("platform:pcf50633-adc");
268