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
18 #include "../iio.h"
19 #include "../trigger.h"
20
21 struct bfin_timer {
22 unsigned short id, bit;
23 unsigned long irqbit;
24 int irq;
25 };
26
27 /*
28 * this covers all hardware timer configurations on
29 * all Blackfin derivatives out there today
30 */
31
32 static struct bfin_timer iio_bfin_timer_code[MAX_BLACKFIN_GPTIMERS] = {
33 {TIMER0_id, TIMER0bit, TIMER_STATUS_TIMIL0, IRQ_TIMER0},
34 {TIMER1_id, TIMER1bit, TIMER_STATUS_TIMIL1, IRQ_TIMER1},
35 {TIMER2_id, TIMER2bit, TIMER_STATUS_TIMIL2, IRQ_TIMER2},
36 #if (MAX_BLACKFIN_GPTIMERS > 3)
37 {TIMER3_id, TIMER3bit, TIMER_STATUS_TIMIL3, IRQ_TIMER3},
38 {TIMER4_id, TIMER4bit, TIMER_STATUS_TIMIL4, IRQ_TIMER4},
39 {TIMER5_id, TIMER5bit, TIMER_STATUS_TIMIL5, IRQ_TIMER5},
40 {TIMER6_id, TIMER6bit, TIMER_STATUS_TIMIL6, IRQ_TIMER6},
41 {TIMER7_id, TIMER7bit, TIMER_STATUS_TIMIL7, IRQ_TIMER7},
42 #endif
43 #if (MAX_BLACKFIN_GPTIMERS > 8)
44 {TIMER8_id, TIMER8bit, TIMER_STATUS_TIMIL8, IRQ_TIMER8},
45 {TIMER9_id, TIMER9bit, TIMER_STATUS_TIMIL9, IRQ_TIMER9},
46 {TIMER10_id, TIMER10bit, TIMER_STATUS_TIMIL10, IRQ_TIMER10},
47 #if (MAX_BLACKFIN_GPTIMERS > 11)
48 {TIMER11_id, TIMER11bit, TIMER_STATUS_TIMIL11, IRQ_TIMER11},
49 #endif
50 #endif
51 };
52
53 struct bfin_tmr_state {
54 struct iio_trigger *trig;
55 struct bfin_timer *t;
56 unsigned timer_num;
57 int irq;
58 };
59
iio_bfin_tmr_frequency_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)60 static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
61 struct device_attribute *attr, const char *buf, size_t count)
62 {
63 struct iio_trigger *trig = dev_get_drvdata(dev);
64 struct bfin_tmr_state *st = trig->private_data;
65 long val;
66 int ret;
67
68 ret = strict_strtoul(buf, 10, &val);
69 if (ret)
70 goto error_ret;
71
72 if (val > 100000) {
73 ret = -EINVAL;
74 goto error_ret;
75 }
76
77 disable_gptimers(st->t->bit);
78
79 if (!val)
80 goto error_ret;
81
82 val = get_sclk() / val;
83 if (val <= 4) {
84 ret = -EINVAL;
85 goto error_ret;
86 }
87
88 set_gptimer_period(st->t->id, val);
89 set_gptimer_pwidth(st->t->id, 1);
90 enable_gptimers(st->t->bit);
91
92 error_ret:
93 return ret ? ret : count;
94 }
95
iio_bfin_tmr_frequency_show(struct device * dev,struct device_attribute * attr,char * buf)96 static ssize_t iio_bfin_tmr_frequency_show(struct device *dev,
97 struct device_attribute *attr,
98 char *buf)
99 {
100 struct iio_trigger *trig = dev_get_drvdata(dev);
101 struct bfin_tmr_state *st = trig->private_data;
102
103 return sprintf(buf, "%lu\n",
104 get_sclk() / get_gptimer_period(st->t->id));
105 }
106
107 static DEVICE_ATTR(frequency, S_IRUGO | S_IWUSR, iio_bfin_tmr_frequency_show,
108 iio_bfin_tmr_frequency_store);
109
110 static struct attribute *iio_bfin_tmr_trigger_attrs[] = {
111 &dev_attr_frequency.attr,
112 NULL,
113 };
114
115 static const struct attribute_group iio_bfin_tmr_trigger_attr_group = {
116 .attrs = iio_bfin_tmr_trigger_attrs,
117 };
118
119 static const struct attribute_group *iio_bfin_tmr_trigger_attr_groups[] = {
120 &iio_bfin_tmr_trigger_attr_group,
121 NULL
122 };
123
124
iio_bfin_tmr_trigger_isr(int irq,void * devid)125 static irqreturn_t iio_bfin_tmr_trigger_isr(int irq, void *devid)
126 {
127 struct bfin_tmr_state *st = devid;
128
129 clear_gptimer_intr(st->t->id);
130 iio_trigger_poll(st->trig, 0);
131
132 return IRQ_HANDLED;
133 }
134
iio_bfin_tmr_get_number(int irq)135 static int iio_bfin_tmr_get_number(int irq)
136 {
137 int i;
138
139 for (i = 0; i < MAX_BLACKFIN_GPTIMERS; i++)
140 if (iio_bfin_timer_code[i].irq == irq)
141 return i;
142
143 return -ENODEV;
144 }
145
146 static const struct iio_trigger_ops iio_bfin_tmr_trigger_ops = {
147 .owner = THIS_MODULE,
148 };
149
iio_bfin_tmr_trigger_probe(struct platform_device * pdev)150 static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
151 {
152 struct bfin_tmr_state *st;
153 int ret;
154
155 st = kzalloc(sizeof(*st), GFP_KERNEL);
156 if (st == NULL) {
157 ret = -ENOMEM;
158 goto out;
159 }
160
161 st->irq = platform_get_irq(pdev, 0);
162 if (!st->irq) {
163 dev_err(&pdev->dev, "No IRQs specified");
164 ret = -ENODEV;
165 goto out1;
166 }
167
168 ret = iio_bfin_tmr_get_number(st->irq);
169 if (ret < 0)
170 goto out1;
171
172 st->timer_num = ret;
173 st->t = &iio_bfin_timer_code[st->timer_num];
174
175 st->trig = iio_allocate_trigger("bfintmr%d", st->timer_num);
176 if (!st->trig) {
177 ret = -ENOMEM;
178 goto out1;
179 }
180
181 st->trig->private_data = st;
182 st->trig->ops = &iio_bfin_tmr_trigger_ops;
183 st->trig->dev.groups = iio_bfin_tmr_trigger_attr_groups;
184 ret = iio_trigger_register(st->trig);
185 if (ret)
186 goto out2;
187
188 ret = request_irq(st->irq, iio_bfin_tmr_trigger_isr,
189 0, st->trig->name, st);
190 if (ret) {
191 dev_err(&pdev->dev,
192 "request IRQ-%d failed", st->irq);
193 goto out4;
194 }
195
196 set_gptimer_config(st->t->id, OUT_DIS | PWM_OUT | PERIOD_CNT | IRQ_ENA);
197
198 dev_info(&pdev->dev, "iio trigger Blackfin TMR%d, IRQ-%d",
199 st->timer_num, st->irq);
200 platform_set_drvdata(pdev, st);
201
202 return 0;
203 out4:
204 iio_trigger_unregister(st->trig);
205 out2:
206 iio_put_trigger(st->trig);
207 out1:
208 kfree(st);
209 out:
210 return ret;
211 }
212
iio_bfin_tmr_trigger_remove(struct platform_device * pdev)213 static int __devexit iio_bfin_tmr_trigger_remove(struct platform_device *pdev)
214 {
215 struct bfin_tmr_state *st = platform_get_drvdata(pdev);
216
217 disable_gptimers(st->t->bit);
218 free_irq(st->irq, st);
219 iio_trigger_unregister(st->trig);
220 iio_put_trigger(st->trig);
221 kfree(st);
222
223 return 0;
224 }
225
226 static struct platform_driver iio_bfin_tmr_trigger_driver = {
227 .driver = {
228 .name = "iio_bfin_tmr_trigger",
229 .owner = THIS_MODULE,
230 },
231 .probe = iio_bfin_tmr_trigger_probe,
232 .remove = __devexit_p(iio_bfin_tmr_trigger_remove),
233 };
234
235 module_platform_driver(iio_bfin_tmr_trigger_driver);
236
237 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
238 MODULE_DESCRIPTION("Blackfin system timer based trigger for the iio subsystem");
239 MODULE_LICENSE("GPL v2");
240 MODULE_ALIAS("platform:iio-trig-bfin-timer");
241