1 /*
2 * Copyright 2011 Analog Devices Inc.
3 *
4 * Licensed under the GPL-2.
5 *
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/slab.h>
12 #include <linux/interrupt.h>
13 #include <linux/irq.h>
14 #include <linux/delay.h>
15
16 #include <asm/gptimers.h>
17 #include <asm/portmux.h>
18
19 #include <linux/iio/iio.h>
20 #include <linux/iio/trigger.h>
21
22 #include "iio-trig-bfin-timer.h"
23
24 struct bfin_timer {
25 unsigned short id, bit;
26 unsigned long irqbit;
27 int irq;
28 int pin;
29 };
30
31 /*
32 * this covers all hardware timer configurations on
33 * all Blackfin derivatives out there today
34 */
35
36 static struct bfin_timer iio_bfin_timer_code[MAX_BLACKFIN_GPTIMERS] = {
37 {TIMER0_id, TIMER0bit, TIMER_STATUS_TIMIL0, IRQ_TIMER0, P_TMR0},
38 {TIMER1_id, TIMER1bit, TIMER_STATUS_TIMIL1, IRQ_TIMER1, P_TMR1},
39 {TIMER2_id, TIMER2bit, TIMER_STATUS_TIMIL2, IRQ_TIMER2, P_TMR2},
40 #if (MAX_BLACKFIN_GPTIMERS > 3)
41 {TIMER3_id, TIMER3bit, TIMER_STATUS_TIMIL3, IRQ_TIMER3, P_TMR3},
42 {TIMER4_id, TIMER4bit, TIMER_STATUS_TIMIL4, IRQ_TIMER4, P_TMR4},
43 {TIMER5_id, TIMER5bit, TIMER_STATUS_TIMIL5, IRQ_TIMER5, P_TMR5},
44 {TIMER6_id, TIMER6bit, TIMER_STATUS_TIMIL6, IRQ_TIMER6, P_TMR6},
45 {TIMER7_id, TIMER7bit, TIMER_STATUS_TIMIL7, IRQ_TIMER7, P_TMR7},
46 #endif
47 #if (MAX_BLACKFIN_GPTIMERS > 8)
48 {TIMER8_id, TIMER8bit, TIMER_STATUS_TIMIL8, IRQ_TIMER8, P_TMR8},
49 {TIMER9_id, TIMER9bit, TIMER_STATUS_TIMIL9, IRQ_TIMER9, P_TMR9},
50 {TIMER10_id, TIMER10bit, TIMER_STATUS_TIMIL10, IRQ_TIMER10, P_TMR10},
51 #if (MAX_BLACKFIN_GPTIMERS > 11)
52 {TIMER11_id, TIMER11bit, TIMER_STATUS_TIMIL11, IRQ_TIMER11, P_TMR11},
53 #endif
54 #endif
55 };
56
57 struct bfin_tmr_state {
58 struct iio_trigger *trig;
59 struct bfin_timer *t;
60 unsigned timer_num;
61 bool output_enable;
62 unsigned int duty;
63 int irq;
64 };
65
iio_bfin_tmr_set_state(struct iio_trigger * trig,bool state)66 static int iio_bfin_tmr_set_state(struct iio_trigger *trig, bool state)
67 {
68 struct bfin_tmr_state *st = iio_trigger_get_drvdata(trig);
69
70 if (get_gptimer_period(st->t->id) == 0)
71 return -EINVAL;
72
73 if (state)
74 enable_gptimers(st->t->bit);
75 else
76 disable_gptimers(st->t->bit);
77
78 return 0;
79 }
80
iio_bfin_tmr_frequency_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)81 static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
82 struct device_attribute *attr,
83 const char *buf, size_t count)
84 {
85 struct iio_trigger *trig = to_iio_trigger(dev);
86 struct bfin_tmr_state *st = iio_trigger_get_drvdata(trig);
87 unsigned int val;
88 bool enabled;
89 int ret;
90
91 ret = kstrtouint(buf, 10, &val);
92 if (ret)
93 return ret;
94
95 if (val > 100000)
96 return -EINVAL;
97
98 enabled = get_enabled_gptimers() & st->t->bit;
99
100 if (enabled)
101 disable_gptimers(st->t->bit);
102
103 if (!val)
104 return count;
105
106 val = get_sclk() / val;
107 if (val <= 4 || val <= st->duty)
108 return -EINVAL;
109
110 set_gptimer_period(st->t->id, val);
111 set_gptimer_pwidth(st->t->id, val - st->duty);
112
113 if (enabled)
114 enable_gptimers(st->t->bit);
115
116 return count;
117 }
118
iio_bfin_tmr_frequency_show(struct device * dev,struct device_attribute * attr,char * buf)119 static ssize_t iio_bfin_tmr_frequency_show(struct device *dev,
120 struct device_attribute *attr,
121 char *buf)
122 {
123 struct iio_trigger *trig = to_iio_trigger(dev);
124 struct bfin_tmr_state *st = iio_trigger_get_drvdata(trig);
125 unsigned int period = get_gptimer_period(st->t->id);
126 unsigned long val;
127
128 if (!period)
129 val = 0;
130 else
131 val = get_sclk() / get_gptimer_period(st->t->id);
132
133 return sprintf(buf, "%lu\n", val);
134 }
135
136 static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR, iio_bfin_tmr_frequency_show,
137 iio_bfin_tmr_frequency_store);
138
139 static struct attribute *iio_bfin_tmr_trigger_attrs[] = {
140 &dev_attr_frequency.attr,
141 NULL,
142 };
143
144 static const struct attribute_group iio_bfin_tmr_trigger_attr_group = {
145 .attrs = iio_bfin_tmr_trigger_attrs,
146 };
147
148 static const struct attribute_group *iio_bfin_tmr_trigger_attr_groups[] = {
149 &iio_bfin_tmr_trigger_attr_group,
150 NULL
151 };
152
iio_bfin_tmr_trigger_isr(int irq,void * devid)153 static irqreturn_t iio_bfin_tmr_trigger_isr(int irq, void *devid)
154 {
155 struct bfin_tmr_state *st = devid;
156
157 clear_gptimer_intr(st->t->id);
158 iio_trigger_poll(st->trig);
159
160 return IRQ_HANDLED;
161 }
162
iio_bfin_tmr_get_number(int irq)163 static int iio_bfin_tmr_get_number(int irq)
164 {
165 int i;
166
167 for (i = 0; i < MAX_BLACKFIN_GPTIMERS; i++)
168 if (iio_bfin_timer_code[i].irq == irq)
169 return i;
170
171 return -ENODEV;
172 }
173
174 static const struct iio_trigger_ops iio_bfin_tmr_trigger_ops = {
175 .owner = THIS_MODULE,
176 .set_trigger_state = iio_bfin_tmr_set_state,
177 };
178
iio_bfin_tmr_trigger_probe(struct platform_device * pdev)179 static int iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
180 {
181 struct iio_bfin_timer_trigger_pdata *pdata = pdev->dev.platform_data;
182 struct bfin_tmr_state *st;
183 unsigned int config;
184 int ret;
185
186 st = devm_kzalloc(&pdev->dev, sizeof(*st), GFP_KERNEL);
187 if (!st)
188 return -ENOMEM;
189
190 st->irq = platform_get_irq(pdev, 0);
191 if (!st->irq) {
192 dev_err(&pdev->dev, "No IRQs specified");
193 return -ENODEV;
194 }
195
196 ret = iio_bfin_tmr_get_number(st->irq);
197 if (ret < 0)
198 return ret;
199
200 st->timer_num = ret;
201 st->t = &iio_bfin_timer_code[st->timer_num];
202
203 st->trig = iio_trigger_alloc("bfintmr%d", st->timer_num);
204 if (!st->trig)
205 return -ENOMEM;
206
207 st->trig->ops = &iio_bfin_tmr_trigger_ops;
208 st->trig->dev.groups = iio_bfin_tmr_trigger_attr_groups;
209 iio_trigger_set_drvdata(st->trig, st);
210 ret = iio_trigger_register(st->trig);
211 if (ret)
212 goto out;
213
214 ret = request_irq(st->irq, iio_bfin_tmr_trigger_isr,
215 0, st->trig->name, st);
216 if (ret) {
217 dev_err(&pdev->dev,
218 "request IRQ-%d failed", st->irq);
219 goto out1;
220 }
221
222 config = PWM_OUT | PERIOD_CNT | IRQ_ENA;
223
224 if (pdata && pdata->output_enable) {
225 unsigned long long val;
226
227 st->output_enable = true;
228
229 ret = peripheral_request(st->t->pin, st->trig->name);
230 if (ret)
231 goto out_free_irq;
232
233 val = (unsigned long long)get_sclk() * pdata->duty_ns;
234 do_div(val, NSEC_PER_SEC);
235 st->duty = val;
236
237 /**
238 * The interrupt will be generated at the end of the period,
239 * since we want the interrupt to be generated at end of the
240 * pulse we invert both polarity and duty cycle, so that the
241 * pulse will be generated directly before the interrupt.
242 */
243 if (pdata->active_low)
244 config |= PULSE_HI;
245 } else {
246 st->duty = 1;
247 config |= OUT_DIS;
248 }
249
250 set_gptimer_config(st->t->id, config);
251
252 dev_info(&pdev->dev, "iio trigger Blackfin TMR%d, IRQ-%d",
253 st->timer_num, st->irq);
254 platform_set_drvdata(pdev, st);
255
256 return 0;
257 out_free_irq:
258 free_irq(st->irq, st);
259 out1:
260 iio_trigger_unregister(st->trig);
261 out:
262 iio_trigger_free(st->trig);
263 return ret;
264 }
265
iio_bfin_tmr_trigger_remove(struct platform_device * pdev)266 static int iio_bfin_tmr_trigger_remove(struct platform_device *pdev)
267 {
268 struct bfin_tmr_state *st = platform_get_drvdata(pdev);
269
270 disable_gptimers(st->t->bit);
271 if (st->output_enable)
272 peripheral_free(st->t->pin);
273 free_irq(st->irq, st);
274 iio_trigger_unregister(st->trig);
275 iio_trigger_free(st->trig);
276
277 return 0;
278 }
279
280 static struct platform_driver iio_bfin_tmr_trigger_driver = {
281 .driver = {
282 .name = "iio_bfin_tmr_trigger",
283 },
284 .probe = iio_bfin_tmr_trigger_probe,
285 .remove = iio_bfin_tmr_trigger_remove,
286 };
287
288 module_platform_driver(iio_bfin_tmr_trigger_driver);
289
290 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
291 MODULE_DESCRIPTION("Blackfin system timer based trigger for the iio subsystem");
292 MODULE_LICENSE("GPL v2");
293 MODULE_ALIAS("platform:iio-trig-bfin-timer");
294