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d5ed4c2e MD |
1 | /* |
2 | * SuperH Timer Support - MTU2 | |
3 | * | |
4 | * Copyright (C) 2009 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/delay.h> | |
26 | #include <linux/io.h> | |
27 | #include <linux/clk.h> | |
28 | #include <linux/irq.h> | |
29 | #include <linux/err.h> | |
30 | #include <linux/clockchips.h> | |
46a12f74 | 31 | #include <linux/sh_timer.h> |
5a0e3ad6 | 32 | #include <linux/slab.h> |
7deeab5d | 33 | #include <linux/module.h> |
d5ed4c2e MD |
34 | |
35 | struct sh_mtu2_priv { | |
36 | void __iomem *mapbase; | |
37 | struct clk *clk; | |
38 | struct irqaction irqaction; | |
39 | struct platform_device *pdev; | |
40 | unsigned long rate; | |
41 | unsigned long periodic; | |
42 | struct clock_event_device ced; | |
43 | }; | |
44 | ||
45 | static DEFINE_SPINLOCK(sh_mtu2_lock); | |
46 | ||
47 | #define TSTR -1 /* shared register */ | |
48 | #define TCR 0 /* channel register */ | |
49 | #define TMDR 1 /* channel register */ | |
50 | #define TIOR 2 /* channel register */ | |
51 | #define TIER 3 /* channel register */ | |
52 | #define TSR 4 /* channel register */ | |
53 | #define TCNT 5 /* channel register */ | |
54 | #define TGR 6 /* channel register */ | |
55 | ||
56 | static unsigned long mtu2_reg_offs[] = { | |
57 | [TCR] = 0, | |
58 | [TMDR] = 1, | |
59 | [TIOR] = 2, | |
60 | [TIER] = 4, | |
61 | [TSR] = 5, | |
62 | [TCNT] = 6, | |
63 | [TGR] = 8, | |
64 | }; | |
65 | ||
66 | static inline unsigned long sh_mtu2_read(struct sh_mtu2_priv *p, int reg_nr) | |
67 | { | |
46a12f74 | 68 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
d5ed4c2e MD |
69 | void __iomem *base = p->mapbase; |
70 | unsigned long offs; | |
71 | ||
72 | if (reg_nr == TSTR) | |
73 | return ioread8(base + cfg->channel_offset); | |
74 | ||
75 | offs = mtu2_reg_offs[reg_nr]; | |
76 | ||
77 | if ((reg_nr == TCNT) || (reg_nr == TGR)) | |
78 | return ioread16(base + offs); | |
79 | else | |
80 | return ioread8(base + offs); | |
81 | } | |
82 | ||
83 | static inline void sh_mtu2_write(struct sh_mtu2_priv *p, int reg_nr, | |
84 | unsigned long value) | |
85 | { | |
46a12f74 | 86 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
d5ed4c2e MD |
87 | void __iomem *base = p->mapbase; |
88 | unsigned long offs; | |
89 | ||
90 | if (reg_nr == TSTR) { | |
91 | iowrite8(value, base + cfg->channel_offset); | |
92 | return; | |
93 | } | |
94 | ||
95 | offs = mtu2_reg_offs[reg_nr]; | |
96 | ||
97 | if ((reg_nr == TCNT) || (reg_nr == TGR)) | |
98 | iowrite16(value, base + offs); | |
99 | else | |
100 | iowrite8(value, base + offs); | |
101 | } | |
102 | ||
103 | static void sh_mtu2_start_stop_ch(struct sh_mtu2_priv *p, int start) | |
104 | { | |
46a12f74 | 105 | struct sh_timer_config *cfg = p->pdev->dev.platform_data; |
d5ed4c2e MD |
106 | unsigned long flags, value; |
107 | ||
108 | /* start stop register shared by multiple timer channels */ | |
109 | spin_lock_irqsave(&sh_mtu2_lock, flags); | |
110 | value = sh_mtu2_read(p, TSTR); | |
111 | ||
112 | if (start) | |
113 | value |= 1 << cfg->timer_bit; | |
114 | else | |
115 | value &= ~(1 << cfg->timer_bit); | |
116 | ||
117 | sh_mtu2_write(p, TSTR, value); | |
118 | spin_unlock_irqrestore(&sh_mtu2_lock, flags); | |
119 | } | |
120 | ||
121 | static int sh_mtu2_enable(struct sh_mtu2_priv *p) | |
122 | { | |
d5ed4c2e MD |
123 | int ret; |
124 | ||
125 | /* enable clock */ | |
126 | ret = clk_enable(p->clk); | |
127 | if (ret) { | |
214a607a | 128 | dev_err(&p->pdev->dev, "cannot enable clock\n"); |
d5ed4c2e MD |
129 | return ret; |
130 | } | |
131 | ||
132 | /* make sure channel is disabled */ | |
133 | sh_mtu2_start_stop_ch(p, 0); | |
134 | ||
135 | p->rate = clk_get_rate(p->clk) / 64; | |
136 | p->periodic = (p->rate + HZ/2) / HZ; | |
137 | ||
138 | /* "Periodic Counter Operation" */ | |
139 | sh_mtu2_write(p, TCR, 0x23); /* TGRA clear, divide clock by 64 */ | |
140 | sh_mtu2_write(p, TIOR, 0); | |
141 | sh_mtu2_write(p, TGR, p->periodic); | |
142 | sh_mtu2_write(p, TCNT, 0); | |
143 | sh_mtu2_write(p, TMDR, 0); | |
144 | sh_mtu2_write(p, TIER, 0x01); | |
145 | ||
146 | /* enable channel */ | |
147 | sh_mtu2_start_stop_ch(p, 1); | |
148 | ||
149 | return 0; | |
150 | } | |
151 | ||
152 | static void sh_mtu2_disable(struct sh_mtu2_priv *p) | |
153 | { | |
154 | /* disable channel */ | |
155 | sh_mtu2_start_stop_ch(p, 0); | |
156 | ||
157 | /* stop clock */ | |
158 | clk_disable(p->clk); | |
159 | } | |
160 | ||
161 | static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id) | |
162 | { | |
163 | struct sh_mtu2_priv *p = dev_id; | |
164 | ||
165 | /* acknowledge interrupt */ | |
166 | sh_mtu2_read(p, TSR); | |
167 | sh_mtu2_write(p, TSR, 0xfe); | |
168 | ||
169 | /* notify clockevent layer */ | |
170 | p->ced.event_handler(&p->ced); | |
171 | return IRQ_HANDLED; | |
172 | } | |
173 | ||
174 | static struct sh_mtu2_priv *ced_to_sh_mtu2(struct clock_event_device *ced) | |
175 | { | |
176 | return container_of(ced, struct sh_mtu2_priv, ced); | |
177 | } | |
178 | ||
179 | static void sh_mtu2_clock_event_mode(enum clock_event_mode mode, | |
180 | struct clock_event_device *ced) | |
181 | { | |
182 | struct sh_mtu2_priv *p = ced_to_sh_mtu2(ced); | |
183 | int disabled = 0; | |
184 | ||
185 | /* deal with old setting first */ | |
186 | switch (ced->mode) { | |
187 | case CLOCK_EVT_MODE_PERIODIC: | |
188 | sh_mtu2_disable(p); | |
189 | disabled = 1; | |
190 | break; | |
191 | default: | |
192 | break; | |
193 | } | |
194 | ||
195 | switch (mode) { | |
196 | case CLOCK_EVT_MODE_PERIODIC: | |
214a607a | 197 | dev_info(&p->pdev->dev, "used for periodic clock events\n"); |
d5ed4c2e MD |
198 | sh_mtu2_enable(p); |
199 | break; | |
200 | case CLOCK_EVT_MODE_UNUSED: | |
201 | if (!disabled) | |
202 | sh_mtu2_disable(p); | |
203 | break; | |
204 | case CLOCK_EVT_MODE_SHUTDOWN: | |
205 | default: | |
206 | break; | |
207 | } | |
208 | } | |
209 | ||
210 | static void sh_mtu2_register_clockevent(struct sh_mtu2_priv *p, | |
211 | char *name, unsigned long rating) | |
212 | { | |
213 | struct clock_event_device *ced = &p->ced; | |
214 | int ret; | |
215 | ||
216 | memset(ced, 0, sizeof(*ced)); | |
217 | ||
218 | ced->name = name; | |
219 | ced->features = CLOCK_EVT_FEAT_PERIODIC; | |
220 | ced->rating = rating; | |
221 | ced->cpumask = cpumask_of(0); | |
222 | ced->set_mode = sh_mtu2_clock_event_mode; | |
223 | ||
214a607a | 224 | dev_info(&p->pdev->dev, "used for clock events\n"); |
da64c2a8 PM |
225 | clockevents_register_device(ced); |
226 | ||
d5ed4c2e MD |
227 | ret = setup_irq(p->irqaction.irq, &p->irqaction); |
228 | if (ret) { | |
214a607a PM |
229 | dev_err(&p->pdev->dev, "failed to request irq %d\n", |
230 | p->irqaction.irq); | |
d5ed4c2e MD |
231 | return; |
232 | } | |
d5ed4c2e MD |
233 | } |
234 | ||
d1fcc0a8 PM |
235 | static int sh_mtu2_register(struct sh_mtu2_priv *p, char *name, |
236 | unsigned long clockevent_rating) | |
d5ed4c2e MD |
237 | { |
238 | if (clockevent_rating) | |
239 | sh_mtu2_register_clockevent(p, name, clockevent_rating); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | static int sh_mtu2_setup(struct sh_mtu2_priv *p, struct platform_device *pdev) | |
245 | { | |
46a12f74 | 246 | struct sh_timer_config *cfg = pdev->dev.platform_data; |
d5ed4c2e MD |
247 | struct resource *res; |
248 | int irq, ret; | |
249 | ret = -ENXIO; | |
250 | ||
251 | memset(p, 0, sizeof(*p)); | |
252 | p->pdev = pdev; | |
253 | ||
254 | if (!cfg) { | |
255 | dev_err(&p->pdev->dev, "missing platform data\n"); | |
256 | goto err0; | |
257 | } | |
258 | ||
259 | platform_set_drvdata(pdev, p); | |
260 | ||
261 | res = platform_get_resource(p->pdev, IORESOURCE_MEM, 0); | |
262 | if (!res) { | |
263 | dev_err(&p->pdev->dev, "failed to get I/O memory\n"); | |
264 | goto err0; | |
265 | } | |
266 | ||
267 | irq = platform_get_irq(p->pdev, 0); | |
268 | if (irq < 0) { | |
269 | dev_err(&p->pdev->dev, "failed to get irq\n"); | |
270 | goto err0; | |
271 | } | |
272 | ||
273 | /* map memory, let mapbase point to our channel */ | |
274 | p->mapbase = ioremap_nocache(res->start, resource_size(res)); | |
275 | if (p->mapbase == NULL) { | |
214a607a | 276 | dev_err(&p->pdev->dev, "failed to remap I/O memory\n"); |
d5ed4c2e MD |
277 | goto err0; |
278 | } | |
279 | ||
280 | /* setup data for setup_irq() (too early for request_irq()) */ | |
214a607a | 281 | p->irqaction.name = dev_name(&p->pdev->dev); |
d5ed4c2e MD |
282 | p->irqaction.handler = sh_mtu2_interrupt; |
283 | p->irqaction.dev_id = p; | |
284 | p->irqaction.irq = irq; | |
fecf066c PM |
285 | p->irqaction.flags = IRQF_DISABLED | IRQF_TIMER | \ |
286 | IRQF_IRQPOLL | IRQF_NOBALANCING; | |
d5ed4c2e MD |
287 | |
288 | /* get hold of clock */ | |
c2a25e81 | 289 | p->clk = clk_get(&p->pdev->dev, "mtu2_fck"); |
d5ed4c2e | 290 | if (IS_ERR(p->clk)) { |
03ff858c MD |
291 | dev_err(&p->pdev->dev, "cannot get clock\n"); |
292 | ret = PTR_ERR(p->clk); | |
293 | goto err1; | |
d5ed4c2e MD |
294 | } |
295 | ||
214a607a PM |
296 | return sh_mtu2_register(p, (char *)dev_name(&p->pdev->dev), |
297 | cfg->clockevent_rating); | |
d5ed4c2e MD |
298 | err1: |
299 | iounmap(p->mapbase); | |
300 | err0: | |
301 | return ret; | |
302 | } | |
303 | ||
304 | static int __devinit sh_mtu2_probe(struct platform_device *pdev) | |
305 | { | |
306 | struct sh_mtu2_priv *p = platform_get_drvdata(pdev); | |
d5ed4c2e MD |
307 | int ret; |
308 | ||
309 | if (p) { | |
214a607a | 310 | dev_info(&pdev->dev, "kept as earlytimer\n"); |
d5ed4c2e MD |
311 | return 0; |
312 | } | |
313 | ||
314 | p = kmalloc(sizeof(*p), GFP_KERNEL); | |
315 | if (p == NULL) { | |
316 | dev_err(&pdev->dev, "failed to allocate driver data\n"); | |
317 | return -ENOMEM; | |
318 | } | |
319 | ||
320 | ret = sh_mtu2_setup(p, pdev); | |
321 | if (ret) { | |
322 | kfree(p); | |
323 | platform_set_drvdata(pdev, NULL); | |
324 | } | |
325 | return ret; | |
326 | } | |
327 | ||
328 | static int __devexit sh_mtu2_remove(struct platform_device *pdev) | |
329 | { | |
330 | return -EBUSY; /* cannot unregister clockevent */ | |
331 | } | |
332 | ||
333 | static struct platform_driver sh_mtu2_device_driver = { | |
334 | .probe = sh_mtu2_probe, | |
335 | .remove = __devexit_p(sh_mtu2_remove), | |
336 | .driver = { | |
337 | .name = "sh_mtu2", | |
338 | } | |
339 | }; | |
340 | ||
341 | static int __init sh_mtu2_init(void) | |
342 | { | |
343 | return platform_driver_register(&sh_mtu2_device_driver); | |
344 | } | |
345 | ||
346 | static void __exit sh_mtu2_exit(void) | |
347 | { | |
348 | platform_driver_unregister(&sh_mtu2_device_driver); | |
349 | } | |
350 | ||
351 | early_platform_init("earlytimer", &sh_mtu2_device_driver); | |
352 | module_init(sh_mtu2_init); | |
353 | module_exit(sh_mtu2_exit); | |
354 | ||
355 | MODULE_AUTHOR("Magnus Damm"); | |
356 | MODULE_DESCRIPTION("SuperH MTU2 Timer Driver"); | |
357 | MODULE_LICENSE("GPL v2"); |