2 * drivers/clk/at91/clk-slow.c
4 * Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
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, or
9 * (at your option) any later version.
13 #include <linux/clk-provider.h>
14 #include <linux/clkdev.h>
15 #include <linux/clk/at91_pmc.h>
16 #include <linux/delay.h>
18 #include <linux/of_address.h>
19 #include <linux/of_irq.h>
21 #include <linux/interrupt.h>
22 #include <linux/irq.h>
23 #include <linux/sched.h>
24 #include <linux/wait.h>
29 #define SLOW_CLOCK_FREQ 32768
30 #define SLOWCK_SW_CYCLES 5
31 #define SLOWCK_SW_TIME_USEC ((SLOWCK_SW_CYCLES * USEC_PER_SEC) / \
34 #define AT91_SCKC_CR 0x00
35 #define AT91_SCKC_RCEN (1 << 0)
36 #define AT91_SCKC_OSC32EN (1 << 1)
37 #define AT91_SCKC_OSC32BYP (1 << 2)
38 #define AT91_SCKC_OSCSEL (1 << 3)
43 unsigned long startup_usec
;
46 #define to_clk_slow_osc(hw) container_of(hw, struct clk_slow_osc, hw)
48 struct clk_slow_rc_osc
{
51 unsigned long frequency
;
52 unsigned long accuracy
;
53 unsigned long startup_usec
;
56 #define to_clk_slow_rc_osc(hw) container_of(hw, struct clk_slow_rc_osc, hw)
58 struct clk_sam9260_slow
{
63 #define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw)
65 struct clk_sam9x5_slow
{
71 #define to_clk_sam9x5_slow(hw) container_of(hw, struct clk_sam9x5_slow, hw)
74 static int clk_slow_osc_prepare(struct clk_hw
*hw
)
76 struct clk_slow_osc
*osc
= to_clk_slow_osc(hw
);
77 void __iomem
*sckcr
= osc
->sckcr
;
78 u32 tmp
= readl(sckcr
);
80 if (tmp
& AT91_SCKC_OSC32BYP
)
83 writel(tmp
| AT91_SCKC_OSC32EN
, sckcr
);
85 usleep_range(osc
->startup_usec
, osc
->startup_usec
+ 1);
90 static void clk_slow_osc_unprepare(struct clk_hw
*hw
)
92 struct clk_slow_osc
*osc
= to_clk_slow_osc(hw
);
93 void __iomem
*sckcr
= osc
->sckcr
;
94 u32 tmp
= readl(sckcr
);
96 if (tmp
& AT91_SCKC_OSC32BYP
)
99 writel(tmp
& ~AT91_SCKC_OSC32EN
, sckcr
);
102 static int clk_slow_osc_is_prepared(struct clk_hw
*hw
)
104 struct clk_slow_osc
*osc
= to_clk_slow_osc(hw
);
105 void __iomem
*sckcr
= osc
->sckcr
;
106 u32 tmp
= readl(sckcr
);
108 if (tmp
& AT91_SCKC_OSC32BYP
)
111 return !!(tmp
& AT91_SCKC_OSC32EN
);
114 static const struct clk_ops slow_osc_ops
= {
115 .prepare
= clk_slow_osc_prepare
,
116 .unprepare
= clk_slow_osc_unprepare
,
117 .is_prepared
= clk_slow_osc_is_prepared
,
120 static struct clk
* __init
121 at91_clk_register_slow_osc(void __iomem
*sckcr
,
123 const char *parent_name
,
124 unsigned long startup
,
127 struct clk_slow_osc
*osc
;
128 struct clk
*clk
= NULL
;
129 struct clk_init_data init
;
131 if (!sckcr
|| !name
|| !parent_name
)
132 return ERR_PTR(-EINVAL
);
134 osc
= kzalloc(sizeof(*osc
), GFP_KERNEL
);
136 return ERR_PTR(-ENOMEM
);
139 init
.ops
= &slow_osc_ops
;
140 init
.parent_names
= &parent_name
;
141 init
.num_parents
= 1;
142 init
.flags
= CLK_IGNORE_UNUSED
;
144 osc
->hw
.init
= &init
;
146 osc
->startup_usec
= startup
;
149 writel((readl(sckcr
) & ~AT91_SCKC_OSC32EN
) | AT91_SCKC_OSC32BYP
,
152 clk
= clk_register(NULL
, &osc
->hw
);
159 void __init
of_at91sam9x5_clk_slow_osc_setup(struct device_node
*np
,
163 const char *parent_name
;
164 const char *name
= np
->name
;
168 parent_name
= of_clk_get_parent_name(np
, 0);
169 of_property_read_string(np
, "clock-output-names", &name
);
170 of_property_read_u32(np
, "atmel,startup-time-usec", &startup
);
171 bypass
= of_property_read_bool(np
, "atmel,osc-bypass");
173 clk
= at91_clk_register_slow_osc(sckcr
, name
, parent_name
, startup
,
178 of_clk_add_provider(np
, of_clk_src_simple_get
, clk
);
181 static unsigned long clk_slow_rc_osc_recalc_rate(struct clk_hw
*hw
,
182 unsigned long parent_rate
)
184 struct clk_slow_rc_osc
*osc
= to_clk_slow_rc_osc(hw
);
186 return osc
->frequency
;
189 static unsigned long clk_slow_rc_osc_recalc_accuracy(struct clk_hw
*hw
,
190 unsigned long parent_acc
)
192 struct clk_slow_rc_osc
*osc
= to_clk_slow_rc_osc(hw
);
194 return osc
->accuracy
;
197 static int clk_slow_rc_osc_prepare(struct clk_hw
*hw
)
199 struct clk_slow_rc_osc
*osc
= to_clk_slow_rc_osc(hw
);
200 void __iomem
*sckcr
= osc
->sckcr
;
202 writel(readl(sckcr
) | AT91_SCKC_RCEN
, sckcr
);
204 usleep_range(osc
->startup_usec
, osc
->startup_usec
+ 1);
209 static void clk_slow_rc_osc_unprepare(struct clk_hw
*hw
)
211 struct clk_slow_rc_osc
*osc
= to_clk_slow_rc_osc(hw
);
212 void __iomem
*sckcr
= osc
->sckcr
;
214 writel(readl(sckcr
) & ~AT91_SCKC_RCEN
, sckcr
);
217 static int clk_slow_rc_osc_is_prepared(struct clk_hw
*hw
)
219 struct clk_slow_rc_osc
*osc
= to_clk_slow_rc_osc(hw
);
221 return !!(readl(osc
->sckcr
) & AT91_SCKC_RCEN
);
224 static const struct clk_ops slow_rc_osc_ops
= {
225 .prepare
= clk_slow_rc_osc_prepare
,
226 .unprepare
= clk_slow_rc_osc_unprepare
,
227 .is_prepared
= clk_slow_rc_osc_is_prepared
,
228 .recalc_rate
= clk_slow_rc_osc_recalc_rate
,
229 .recalc_accuracy
= clk_slow_rc_osc_recalc_accuracy
,
232 static struct clk
* __init
233 at91_clk_register_slow_rc_osc(void __iomem
*sckcr
,
235 unsigned long frequency
,
236 unsigned long accuracy
,
237 unsigned long startup
)
239 struct clk_slow_rc_osc
*osc
;
240 struct clk
*clk
= NULL
;
241 struct clk_init_data init
;
244 return ERR_PTR(-EINVAL
);
246 osc
= kzalloc(sizeof(*osc
), GFP_KERNEL
);
248 return ERR_PTR(-ENOMEM
);
251 init
.ops
= &slow_rc_osc_ops
;
252 init
.parent_names
= NULL
;
253 init
.num_parents
= 0;
254 init
.flags
= CLK_IS_ROOT
| CLK_IGNORE_UNUSED
;
256 osc
->hw
.init
= &init
;
258 osc
->frequency
= frequency
;
259 osc
->accuracy
= accuracy
;
260 osc
->startup_usec
= startup
;
262 clk
= clk_register(NULL
, &osc
->hw
);
269 void __init
of_at91sam9x5_clk_slow_rc_osc_setup(struct device_node
*np
,
276 const char *name
= np
->name
;
278 of_property_read_string(np
, "clock-output-names", &name
);
279 of_property_read_u32(np
, "clock-frequency", &frequency
);
280 of_property_read_u32(np
, "clock-accuracy", &accuracy
);
281 of_property_read_u32(np
, "atmel,startup-time-usec", &startup
);
283 clk
= at91_clk_register_slow_rc_osc(sckcr
, name
, frequency
, accuracy
,
288 of_clk_add_provider(np
, of_clk_src_simple_get
, clk
);
291 static int clk_sam9x5_slow_set_parent(struct clk_hw
*hw
, u8 index
)
293 struct clk_sam9x5_slow
*slowck
= to_clk_sam9x5_slow(hw
);
294 void __iomem
*sckcr
= slowck
->sckcr
;
302 if ((!index
&& !(tmp
& AT91_SCKC_OSCSEL
)) ||
303 (index
&& (tmp
& AT91_SCKC_OSCSEL
)))
307 tmp
|= AT91_SCKC_OSCSEL
;
309 tmp
&= ~AT91_SCKC_OSCSEL
;
313 usleep_range(SLOWCK_SW_TIME_USEC
, SLOWCK_SW_TIME_USEC
+ 1);
318 static u8
clk_sam9x5_slow_get_parent(struct clk_hw
*hw
)
320 struct clk_sam9x5_slow
*slowck
= to_clk_sam9x5_slow(hw
);
322 return !!(readl(slowck
->sckcr
) & AT91_SCKC_OSCSEL
);
325 static const struct clk_ops sam9x5_slow_ops
= {
326 .set_parent
= clk_sam9x5_slow_set_parent
,
327 .get_parent
= clk_sam9x5_slow_get_parent
,
330 static struct clk
* __init
331 at91_clk_register_sam9x5_slow(void __iomem
*sckcr
,
333 const char **parent_names
,
336 struct clk_sam9x5_slow
*slowck
;
337 struct clk
*clk
= NULL
;
338 struct clk_init_data init
;
340 if (!sckcr
|| !name
|| !parent_names
|| !num_parents
)
341 return ERR_PTR(-EINVAL
);
343 slowck
= kzalloc(sizeof(*slowck
), GFP_KERNEL
);
345 return ERR_PTR(-ENOMEM
);
348 init
.ops
= &sam9x5_slow_ops
;
349 init
.parent_names
= parent_names
;
350 init
.num_parents
= num_parents
;
353 slowck
->hw
.init
= &init
;
354 slowck
->sckcr
= sckcr
;
355 slowck
->parent
= !!(readl(sckcr
) & AT91_SCKC_OSCSEL
);
357 clk
= clk_register(NULL
, &slowck
->hw
);
364 void __init
of_at91sam9x5_clk_slow_setup(struct device_node
*np
,
368 const char *parent_names
[2];
370 const char *name
= np
->name
;
373 num_parents
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
374 if (num_parents
<= 0 || num_parents
> 2)
377 for (i
= 0; i
< num_parents
; ++i
) {
378 parent_names
[i
] = of_clk_get_parent_name(np
, i
);
379 if (!parent_names
[i
])
383 of_property_read_string(np
, "clock-output-names", &name
);
385 clk
= at91_clk_register_sam9x5_slow(sckcr
, name
, parent_names
,
390 of_clk_add_provider(np
, of_clk_src_simple_get
, clk
);
393 static u8
clk_sam9260_slow_get_parent(struct clk_hw
*hw
)
395 struct clk_sam9260_slow
*slowck
= to_clk_sam9260_slow(hw
);
397 return !!(pmc_read(slowck
->pmc
, AT91_PMC_SR
) & AT91_PMC_OSCSEL
);
400 static const struct clk_ops sam9260_slow_ops
= {
401 .get_parent
= clk_sam9260_slow_get_parent
,
404 static struct clk
* __init
405 at91_clk_register_sam9260_slow(struct at91_pmc
*pmc
,
407 const char **parent_names
,
410 struct clk_sam9260_slow
*slowck
;
411 struct clk
*clk
= NULL
;
412 struct clk_init_data init
;
415 return ERR_PTR(-EINVAL
);
417 if (!parent_names
|| !num_parents
)
418 return ERR_PTR(-EINVAL
);
420 slowck
= kzalloc(sizeof(*slowck
), GFP_KERNEL
);
422 return ERR_PTR(-ENOMEM
);
425 init
.ops
= &sam9260_slow_ops
;
426 init
.parent_names
= parent_names
;
427 init
.num_parents
= num_parents
;
430 slowck
->hw
.init
= &init
;
433 clk
= clk_register(NULL
, &slowck
->hw
);
440 void __init
of_at91sam9260_clk_slow_setup(struct device_node
*np
,
441 struct at91_pmc
*pmc
)
444 const char *parent_names
[2];
446 const char *name
= np
->name
;
449 num_parents
= of_count_phandle_with_args(np
, "clocks", "#clock-cells");
450 if (num_parents
<= 0 || num_parents
> 1)
453 for (i
= 0; i
< num_parents
; ++i
) {
454 parent_names
[i
] = of_clk_get_parent_name(np
, i
);
455 if (!parent_names
[i
])
459 of_property_read_string(np
, "clock-output-names", &name
);
461 clk
= at91_clk_register_sam9260_slow(pmc
, name
, parent_names
,
466 of_clk_add_provider(np
, of_clk_src_simple_get
, clk
);