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1/*
2 * Emma Mobile Timer Support - STI
3 *
4 * Copyright (C) 2012 Magnus Damm
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/init.h>
21#include <linux/platform_device.h>
22#include <linux/spinlock.h>
23#include <linux/interrupt.h>
24#include <linux/ioport.h>
25#include <linux/io.h>
26#include <linux/clk.h>
27#include <linux/irq.h>
28#include <linux/err.h>
29#include <linux/delay.h>
30#include <linux/clocksource.h>
31#include <linux/clockchips.h>
32#include <linux/slab.h>
33#include <linux/module.h>
34
35enum { USER_CLOCKSOURCE, USER_CLOCKEVENT, USER_NR };
36
37struct em_sti_priv {
38 void __iomem *base;
39 struct clk *clk;
40 struct platform_device *pdev;
41 unsigned int active[USER_NR];
42 unsigned long rate;
43 raw_spinlock_t lock;
44 struct clock_event_device ced;
45 struct clocksource cs;
46};
47
48#define STI_CONTROL 0x00
49#define STI_COMPA_H 0x10
50#define STI_COMPA_L 0x14
51#define STI_COMPB_H 0x18
52#define STI_COMPB_L 0x1c
53#define STI_COUNT_H 0x20
54#define STI_COUNT_L 0x24
55#define STI_COUNT_RAW_H 0x28
56#define STI_COUNT_RAW_L 0x2c
57#define STI_SET_H 0x30
58#define STI_SET_L 0x34
59#define STI_INTSTATUS 0x40
60#define STI_INTRAWSTATUS 0x44
61#define STI_INTENSET 0x48
62#define STI_INTENCLR 0x4c
63#define STI_INTFFCLR 0x50
64
65static inline unsigned long em_sti_read(struct em_sti_priv *p, int offs)
66{
67 return ioread32(p->base + offs);
68}
69
70static inline void em_sti_write(struct em_sti_priv *p, int offs,
71 unsigned long value)
72{
73 iowrite32(value, p->base + offs);
74}
75
76static int em_sti_enable(struct em_sti_priv *p)
77{
78 int ret;
79
80 /* enable clock */
81 ret = clk_enable(p->clk);
82 if (ret) {
83 dev_err(&p->pdev->dev, "cannot enable clock\n");
84 return ret;
85 }
86
87 /* configure channel, periodic mode and maximum timeout */
88 p->rate = clk_get_rate(p->clk);
89
90 /* reset the counter */
91 em_sti_write(p, STI_SET_H, 0x40000000);
92 em_sti_write(p, STI_SET_L, 0x00000000);
93
94 /* mask and clear pending interrupts */
95 em_sti_write(p, STI_INTENCLR, 3);
96 em_sti_write(p, STI_INTFFCLR, 3);
97
98 /* enable updates of counter registers */
99 em_sti_write(p, STI_CONTROL, 1);
100
101 return 0;
102}
103
104static void em_sti_disable(struct em_sti_priv *p)
105{
106 /* mask interrupts */
107 em_sti_write(p, STI_INTENCLR, 3);
108
109 /* stop clock */
110 clk_disable(p->clk);
111}
112
113static cycle_t em_sti_count(struct em_sti_priv *p)
114{
115 cycle_t ticks;
116 unsigned long flags;
117
118 /* the STI hardware buffers the 48-bit count, but to
119 * break it out into two 32-bit access the registers
120 * must be accessed in a certain order.
121 * Always read STI_COUNT_H before STI_COUNT_L.
122 */
123 raw_spin_lock_irqsave(&p->lock, flags);
124 ticks = (cycle_t)(em_sti_read(p, STI_COUNT_H) & 0xffff) << 32;
125 ticks |= em_sti_read(p, STI_COUNT_L);
126 raw_spin_unlock_irqrestore(&p->lock, flags);
127
128 return ticks;
129}
130
131static cycle_t em_sti_set_next(struct em_sti_priv *p, cycle_t next)
132{
133 unsigned long flags;
134
135 raw_spin_lock_irqsave(&p->lock, flags);
136
137 /* mask compare A interrupt */
138 em_sti_write(p, STI_INTENCLR, 1);
139
140 /* update compare A value */
141 em_sti_write(p, STI_COMPA_H, next >> 32);
142 em_sti_write(p, STI_COMPA_L, next & 0xffffffff);
143
144 /* clear compare A interrupt source */
145 em_sti_write(p, STI_INTFFCLR, 1);
146
147 /* unmask compare A interrupt */
148 em_sti_write(p, STI_INTENSET, 1);
149
150 raw_spin_unlock_irqrestore(&p->lock, flags);
151
152 return next;
153}
154
155static irqreturn_t em_sti_interrupt(int irq, void *dev_id)
156{
157 struct em_sti_priv *p = dev_id;
158
159 p->ced.event_handler(&p->ced);
160 return IRQ_HANDLED;
161}
162
163static int em_sti_start(struct em_sti_priv *p, unsigned int user)
164{
165 unsigned long flags;
166 int used_before;
167 int ret = 0;
168
169 raw_spin_lock_irqsave(&p->lock, flags);
170 used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
171 if (!used_before)
172 ret = em_sti_enable(p);
173
174 if (!ret)
175 p->active[user] = 1;
176 raw_spin_unlock_irqrestore(&p->lock, flags);
177
178 return ret;
179}
180
181static void em_sti_stop(struct em_sti_priv *p, unsigned int user)
182{
183 unsigned long flags;
184 int used_before, used_after;
185
186 raw_spin_lock_irqsave(&p->lock, flags);
187 used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
188 p->active[user] = 0;
189 used_after = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
190
191 if (used_before && !used_after)
192 em_sti_disable(p);
193 raw_spin_unlock_irqrestore(&p->lock, flags);
194}
195
196static struct em_sti_priv *cs_to_em_sti(struct clocksource *cs)
197{
198 return container_of(cs, struct em_sti_priv, cs);
199}
200
201static cycle_t em_sti_clocksource_read(struct clocksource *cs)
202{
203 return em_sti_count(cs_to_em_sti(cs));
204}
205
206static int em_sti_clocksource_enable(struct clocksource *cs)
207{
208 int ret;
209 struct em_sti_priv *p = cs_to_em_sti(cs);
210
211 ret = em_sti_start(p, USER_CLOCKSOURCE);
212 if (!ret)
213 __clocksource_updatefreq_hz(cs, p->rate);
214 return ret;
215}
216
217static void em_sti_clocksource_disable(struct clocksource *cs)
218{
219 em_sti_stop(cs_to_em_sti(cs), USER_CLOCKSOURCE);
220}
221
222static void em_sti_clocksource_resume(struct clocksource *cs)
223{
224 em_sti_clocksource_enable(cs);
225}
226
227static int em_sti_register_clocksource(struct em_sti_priv *p)
228{
229 struct clocksource *cs = &p->cs;
230
231 memset(cs, 0, sizeof(*cs));
232 cs->name = dev_name(&p->pdev->dev);
233 cs->rating = 200;
234 cs->read = em_sti_clocksource_read;
235 cs->enable = em_sti_clocksource_enable;
236 cs->disable = em_sti_clocksource_disable;
237 cs->suspend = em_sti_clocksource_disable;
238 cs->resume = em_sti_clocksource_resume;
239 cs->mask = CLOCKSOURCE_MASK(48);
240 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
241
242 dev_info(&p->pdev->dev, "used as clock source\n");
243
244 /* Register with dummy 1 Hz value, gets updated in ->enable() */
245 clocksource_register_hz(cs, 1);
246 return 0;
247}
248
249static struct em_sti_priv *ced_to_em_sti(struct clock_event_device *ced)
250{
251 return container_of(ced, struct em_sti_priv, ced);
252}
253
254static void em_sti_clock_event_mode(enum clock_event_mode mode,
255 struct clock_event_device *ced)
256{
257 struct em_sti_priv *p = ced_to_em_sti(ced);
258
259 /* deal with old setting first */
260 switch (ced->mode) {
261 case CLOCK_EVT_MODE_ONESHOT:
262 em_sti_stop(p, USER_CLOCKEVENT);
263 break;
264 default:
265 break;
266 }
267
268 switch (mode) {
269 case CLOCK_EVT_MODE_ONESHOT:
270 dev_info(&p->pdev->dev, "used for oneshot clock events\n");
271 em_sti_start(p, USER_CLOCKEVENT);
272 clockevents_config(&p->ced, p->rate);
273 break;
274 case CLOCK_EVT_MODE_SHUTDOWN:
275 case CLOCK_EVT_MODE_UNUSED:
276 em_sti_stop(p, USER_CLOCKEVENT);
277 break;
278 default:
279 break;
280 }
281}
282
283static int em_sti_clock_event_next(unsigned long delta,
284 struct clock_event_device *ced)
285{
286 struct em_sti_priv *p = ced_to_em_sti(ced);
287 cycle_t next;
288 int safe;
289
290 next = em_sti_set_next(p, em_sti_count(p) + delta);
291 safe = em_sti_count(p) < (next - 1);
292
293 return !safe;
294}
295
296static void em_sti_register_clockevent(struct em_sti_priv *p)
297{
298 struct clock_event_device *ced = &p->ced;
299
300 memset(ced, 0, sizeof(*ced));
301 ced->name = dev_name(&p->pdev->dev);
302 ced->features = CLOCK_EVT_FEAT_ONESHOT;
303 ced->rating = 200;
304 ced->cpumask = cpumask_of(0);
305 ced->set_next_event = em_sti_clock_event_next;
306 ced->set_mode = em_sti_clock_event_mode;
307
308 dev_info(&p->pdev->dev, "used for clock events\n");
309
310 /* Register with dummy 1 Hz value, gets updated in ->set_mode() */
311 clockevents_config_and_register(ced, 1, 2, 0xffffffff);
312}
313
314static int __devinit em_sti_probe(struct platform_device *pdev)
315{
316 struct em_sti_priv *p;
317 struct resource *res;
318 int irq, ret;
319
320 p = kzalloc(sizeof(*p), GFP_KERNEL);
321 if (p == NULL) {
322 dev_err(&pdev->dev, "failed to allocate driver data\n");
323 ret = -ENOMEM;
324 goto err0;
325 }
326
327 p->pdev = pdev;
328 platform_set_drvdata(pdev, p);
329
330 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
331 if (!res) {
332 dev_err(&pdev->dev, "failed to get I/O memory\n");
333 ret = -EINVAL;
334 goto err0;
335 }
336
337 irq = platform_get_irq(pdev, 0);
338 if (irq < 0) {
339 dev_err(&pdev->dev, "failed to get irq\n");
340 ret = -EINVAL;
341 goto err0;
342 }
343
344 /* map memory, let base point to the STI instance */
345 p->base = ioremap_nocache(res->start, resource_size(res));
346 if (p->base == NULL) {
347 dev_err(&pdev->dev, "failed to remap I/O memory\n");
348 ret = -ENXIO;
349 goto err0;
350 }
351
352 /* get hold of clock */
353 p->clk = clk_get(&pdev->dev, "sclk");
354 if (IS_ERR(p->clk)) {
355 dev_err(&pdev->dev, "cannot get clock\n");
356 ret = PTR_ERR(p->clk);
357 goto err1;
358 }
359
360 if (request_irq(irq, em_sti_interrupt,
361 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
362 dev_name(&pdev->dev), p)) {
363 dev_err(&pdev->dev, "failed to request low IRQ\n");
364 ret = -ENOENT;
365 goto err2;
366 }
367
368 raw_spin_lock_init(&p->lock);
369 em_sti_register_clockevent(p);
370 em_sti_register_clocksource(p);
371 return 0;
372
373err2:
374 clk_put(p->clk);
375err1:
376 iounmap(p->base);
377err0:
378 kfree(p);
379 return ret;
380}
381
382static int __devexit em_sti_remove(struct platform_device *pdev)
383{
384 return -EBUSY; /* cannot unregister clockevent and clocksource */
385}
386
387static const struct of_device_id em_sti_dt_ids[] __devinitconst = {
388 { .compatible = "renesas,em-sti", },
389 {},
390};
391MODULE_DEVICE_TABLE(of, em_sti_dt_ids);
392
393static struct platform_driver em_sti_device_driver = {
394 .probe = em_sti_probe,
395 .remove = __devexit_p(em_sti_remove),
396 .driver = {
397 .name = "em_sti",
398 .of_match_table = em_sti_dt_ids,
399 }
400};
401
402module_platform_driver(em_sti_device_driver);
403
404MODULE_AUTHOR("Magnus Damm");
405MODULE_DESCRIPTION("Renesas Emma Mobile STI Timer Driver");
406MODULE_LICENSE("GPL v2");
1/*
2 * Emma Mobile Timer Support - STI
3 *
4 * Copyright (C) 2012 Magnus Damm
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 */
19
20#include <linux/init.h>
21#include <linux/platform_device.h>
22#include <linux/spinlock.h>
23#include <linux/interrupt.h>
24#include <linux/ioport.h>
25#include <linux/io.h>
26#include <linux/clk.h>
27#include <linux/irq.h>
28#include <linux/err.h>
29#include <linux/delay.h>
30#include <linux/clocksource.h>
31#include <linux/clockchips.h>
32#include <linux/slab.h>
33#include <linux/module.h>
34
35enum { USER_CLOCKSOURCE, USER_CLOCKEVENT, USER_NR };
36
37struct em_sti_priv {
38 void __iomem *base;
39 struct clk *clk;
40 struct platform_device *pdev;
41 unsigned int active[USER_NR];
42 unsigned long rate;
43 raw_spinlock_t lock;
44 struct clock_event_device ced;
45 struct clocksource cs;
46};
47
48#define STI_CONTROL 0x00
49#define STI_COMPA_H 0x10
50#define STI_COMPA_L 0x14
51#define STI_COMPB_H 0x18
52#define STI_COMPB_L 0x1c
53#define STI_COUNT_H 0x20
54#define STI_COUNT_L 0x24
55#define STI_COUNT_RAW_H 0x28
56#define STI_COUNT_RAW_L 0x2c
57#define STI_SET_H 0x30
58#define STI_SET_L 0x34
59#define STI_INTSTATUS 0x40
60#define STI_INTRAWSTATUS 0x44
61#define STI_INTENSET 0x48
62#define STI_INTENCLR 0x4c
63#define STI_INTFFCLR 0x50
64
65static inline unsigned long em_sti_read(struct em_sti_priv *p, int offs)
66{
67 return ioread32(p->base + offs);
68}
69
70static inline void em_sti_write(struct em_sti_priv *p, int offs,
71 unsigned long value)
72{
73 iowrite32(value, p->base + offs);
74}
75
76static int em_sti_enable(struct em_sti_priv *p)
77{
78 int ret;
79
80 /* enable clock */
81 ret = clk_prepare_enable(p->clk);
82 if (ret) {
83 dev_err(&p->pdev->dev, "cannot enable clock\n");
84 return ret;
85 }
86
87 /* configure channel, periodic mode and maximum timeout */
88 p->rate = clk_get_rate(p->clk);
89
90 /* reset the counter */
91 em_sti_write(p, STI_SET_H, 0x40000000);
92 em_sti_write(p, STI_SET_L, 0x00000000);
93
94 /* mask and clear pending interrupts */
95 em_sti_write(p, STI_INTENCLR, 3);
96 em_sti_write(p, STI_INTFFCLR, 3);
97
98 /* enable updates of counter registers */
99 em_sti_write(p, STI_CONTROL, 1);
100
101 return 0;
102}
103
104static void em_sti_disable(struct em_sti_priv *p)
105{
106 /* mask interrupts */
107 em_sti_write(p, STI_INTENCLR, 3);
108
109 /* stop clock */
110 clk_disable_unprepare(p->clk);
111}
112
113static cycle_t em_sti_count(struct em_sti_priv *p)
114{
115 cycle_t ticks;
116 unsigned long flags;
117
118 /* the STI hardware buffers the 48-bit count, but to
119 * break it out into two 32-bit access the registers
120 * must be accessed in a certain order.
121 * Always read STI_COUNT_H before STI_COUNT_L.
122 */
123 raw_spin_lock_irqsave(&p->lock, flags);
124 ticks = (cycle_t)(em_sti_read(p, STI_COUNT_H) & 0xffff) << 32;
125 ticks |= em_sti_read(p, STI_COUNT_L);
126 raw_spin_unlock_irqrestore(&p->lock, flags);
127
128 return ticks;
129}
130
131static cycle_t em_sti_set_next(struct em_sti_priv *p, cycle_t next)
132{
133 unsigned long flags;
134
135 raw_spin_lock_irqsave(&p->lock, flags);
136
137 /* mask compare A interrupt */
138 em_sti_write(p, STI_INTENCLR, 1);
139
140 /* update compare A value */
141 em_sti_write(p, STI_COMPA_H, next >> 32);
142 em_sti_write(p, STI_COMPA_L, next & 0xffffffff);
143
144 /* clear compare A interrupt source */
145 em_sti_write(p, STI_INTFFCLR, 1);
146
147 /* unmask compare A interrupt */
148 em_sti_write(p, STI_INTENSET, 1);
149
150 raw_spin_unlock_irqrestore(&p->lock, flags);
151
152 return next;
153}
154
155static irqreturn_t em_sti_interrupt(int irq, void *dev_id)
156{
157 struct em_sti_priv *p = dev_id;
158
159 p->ced.event_handler(&p->ced);
160 return IRQ_HANDLED;
161}
162
163static int em_sti_start(struct em_sti_priv *p, unsigned int user)
164{
165 unsigned long flags;
166 int used_before;
167 int ret = 0;
168
169 raw_spin_lock_irqsave(&p->lock, flags);
170 used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
171 if (!used_before)
172 ret = em_sti_enable(p);
173
174 if (!ret)
175 p->active[user] = 1;
176 raw_spin_unlock_irqrestore(&p->lock, flags);
177
178 return ret;
179}
180
181static void em_sti_stop(struct em_sti_priv *p, unsigned int user)
182{
183 unsigned long flags;
184 int used_before, used_after;
185
186 raw_spin_lock_irqsave(&p->lock, flags);
187 used_before = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
188 p->active[user] = 0;
189 used_after = p->active[USER_CLOCKSOURCE] | p->active[USER_CLOCKEVENT];
190
191 if (used_before && !used_after)
192 em_sti_disable(p);
193 raw_spin_unlock_irqrestore(&p->lock, flags);
194}
195
196static struct em_sti_priv *cs_to_em_sti(struct clocksource *cs)
197{
198 return container_of(cs, struct em_sti_priv, cs);
199}
200
201static cycle_t em_sti_clocksource_read(struct clocksource *cs)
202{
203 return em_sti_count(cs_to_em_sti(cs));
204}
205
206static int em_sti_clocksource_enable(struct clocksource *cs)
207{
208 int ret;
209 struct em_sti_priv *p = cs_to_em_sti(cs);
210
211 ret = em_sti_start(p, USER_CLOCKSOURCE);
212 if (!ret)
213 __clocksource_updatefreq_hz(cs, p->rate);
214 return ret;
215}
216
217static void em_sti_clocksource_disable(struct clocksource *cs)
218{
219 em_sti_stop(cs_to_em_sti(cs), USER_CLOCKSOURCE);
220}
221
222static void em_sti_clocksource_resume(struct clocksource *cs)
223{
224 em_sti_clocksource_enable(cs);
225}
226
227static int em_sti_register_clocksource(struct em_sti_priv *p)
228{
229 struct clocksource *cs = &p->cs;
230
231 memset(cs, 0, sizeof(*cs));
232 cs->name = dev_name(&p->pdev->dev);
233 cs->rating = 200;
234 cs->read = em_sti_clocksource_read;
235 cs->enable = em_sti_clocksource_enable;
236 cs->disable = em_sti_clocksource_disable;
237 cs->suspend = em_sti_clocksource_disable;
238 cs->resume = em_sti_clocksource_resume;
239 cs->mask = CLOCKSOURCE_MASK(48);
240 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS;
241
242 dev_info(&p->pdev->dev, "used as clock source\n");
243
244 /* Register with dummy 1 Hz value, gets updated in ->enable() */
245 clocksource_register_hz(cs, 1);
246 return 0;
247}
248
249static struct em_sti_priv *ced_to_em_sti(struct clock_event_device *ced)
250{
251 return container_of(ced, struct em_sti_priv, ced);
252}
253
254static void em_sti_clock_event_mode(enum clock_event_mode mode,
255 struct clock_event_device *ced)
256{
257 struct em_sti_priv *p = ced_to_em_sti(ced);
258
259 /* deal with old setting first */
260 switch (ced->mode) {
261 case CLOCK_EVT_MODE_ONESHOT:
262 em_sti_stop(p, USER_CLOCKEVENT);
263 break;
264 default:
265 break;
266 }
267
268 switch (mode) {
269 case CLOCK_EVT_MODE_ONESHOT:
270 dev_info(&p->pdev->dev, "used for oneshot clock events\n");
271 em_sti_start(p, USER_CLOCKEVENT);
272 clockevents_config(&p->ced, p->rate);
273 break;
274 case CLOCK_EVT_MODE_SHUTDOWN:
275 case CLOCK_EVT_MODE_UNUSED:
276 em_sti_stop(p, USER_CLOCKEVENT);
277 break;
278 default:
279 break;
280 }
281}
282
283static int em_sti_clock_event_next(unsigned long delta,
284 struct clock_event_device *ced)
285{
286 struct em_sti_priv *p = ced_to_em_sti(ced);
287 cycle_t next;
288 int safe;
289
290 next = em_sti_set_next(p, em_sti_count(p) + delta);
291 safe = em_sti_count(p) < (next - 1);
292
293 return !safe;
294}
295
296static void em_sti_register_clockevent(struct em_sti_priv *p)
297{
298 struct clock_event_device *ced = &p->ced;
299
300 memset(ced, 0, sizeof(*ced));
301 ced->name = dev_name(&p->pdev->dev);
302 ced->features = CLOCK_EVT_FEAT_ONESHOT;
303 ced->rating = 200;
304 ced->cpumask = cpu_possible_mask;
305 ced->set_next_event = em_sti_clock_event_next;
306 ced->set_mode = em_sti_clock_event_mode;
307
308 dev_info(&p->pdev->dev, "used for clock events\n");
309
310 /* Register with dummy 1 Hz value, gets updated in ->set_mode() */
311 clockevents_config_and_register(ced, 1, 2, 0xffffffff);
312}
313
314static int em_sti_probe(struct platform_device *pdev)
315{
316 struct em_sti_priv *p;
317 struct resource *res;
318 int irq;
319
320 p = devm_kzalloc(&pdev->dev, sizeof(*p), GFP_KERNEL);
321 if (p == NULL) {
322 dev_err(&pdev->dev, "failed to allocate driver data\n");
323 return -ENOMEM;
324 }
325
326 p->pdev = pdev;
327 platform_set_drvdata(pdev, p);
328
329 irq = platform_get_irq(pdev, 0);
330 if (irq < 0) {
331 dev_err(&pdev->dev, "failed to get irq\n");
332 return -EINVAL;
333 }
334
335 /* map memory, let base point to the STI instance */
336 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
337 p->base = devm_ioremap_resource(&pdev->dev, res);
338 if (IS_ERR(p->base))
339 return PTR_ERR(p->base);
340
341 /* get hold of clock */
342 p->clk = devm_clk_get(&pdev->dev, "sclk");
343 if (IS_ERR(p->clk)) {
344 dev_err(&pdev->dev, "cannot get clock\n");
345 return PTR_ERR(p->clk);
346 }
347
348 if (devm_request_irq(&pdev->dev, irq, em_sti_interrupt,
349 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
350 dev_name(&pdev->dev), p)) {
351 dev_err(&pdev->dev, "failed to request low IRQ\n");
352 return -ENOENT;
353 }
354
355 raw_spin_lock_init(&p->lock);
356 em_sti_register_clockevent(p);
357 em_sti_register_clocksource(p);
358 return 0;
359}
360
361static int em_sti_remove(struct platform_device *pdev)
362{
363 return -EBUSY; /* cannot unregister clockevent and clocksource */
364}
365
366static const struct of_device_id em_sti_dt_ids[] = {
367 { .compatible = "renesas,em-sti", },
368 {},
369};
370MODULE_DEVICE_TABLE(of, em_sti_dt_ids);
371
372static struct platform_driver em_sti_device_driver = {
373 .probe = em_sti_probe,
374 .remove = em_sti_remove,
375 .driver = {
376 .name = "em_sti",
377 .of_match_table = em_sti_dt_ids,
378 }
379};
380
381static int __init em_sti_init(void)
382{
383 return platform_driver_register(&em_sti_device_driver);
384}
385
386static void __exit em_sti_exit(void)
387{
388 platform_driver_unregister(&em_sti_device_driver);
389}
390
391subsys_initcall(em_sti_init);
392module_exit(em_sti_exit);
393
394MODULE_AUTHOR("Magnus Damm");
395MODULE_DESCRIPTION("Renesas Emma Mobile STI Timer Driver");
396MODULE_LICENSE("GPL v2");