1 /*
2 * arch/arm/mach-lpc32xx/clock.c
3 *
4 * Author: Kevin Wells <kevin.wells@nxp.com>
5 *
6 * Copyright (C) 2010 NXP Semiconductors
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19 /*
20 * LPC32xx clock management driver overview
21 *
22 * The LPC32XX contains a number of high level system clocks that can be
23 * generated from different sources. These system clocks are used to
24 * generate the CPU and bus rates and the individual peripheral clocks in
25 * the system. When Linux is started by the boot loader, the system
26 * clocks are already running. Stopping a system clock during normal
27 * Linux operation should never be attempted, as peripherals that require
28 * those clocks will quit working (ie, DRAM).
29 *
30 * The LPC32xx high level clock tree looks as follows. Clocks marked with
31 * an asterisk are always on and cannot be disabled. Clocks marked with
32 * an ampersand can only be disabled in CPU suspend mode. Clocks marked
33 * with a caret are always on if it is the selected clock for the SYSCLK
34 * source. The clock that isn't used for SYSCLK can be enabled and
35 * disabled normally.
36 * 32KHz oscillator*
37 * / | \
38 * RTC* PLL397^ TOUCH
39 * /
40 * Main oscillator^ /
41 * | \ /
42 * | SYSCLK&
43 * | \
44 * | \
45 * USB_PLL HCLK_PLL&
46 * | | |
47 * USB host/device PCLK& |
48 * | |
49 * Peripherals
50 *
51 * The CPU and chip bus rates are derived from the HCLK PLL, which can
52 * generate various clock rates up to 266MHz and beyond. The internal bus
53 * rates (PCLK and HCLK) are generated from dividers based on the HCLK
54 * PLL rate. HCLK can be a ratio of 1:1, 1:2, or 1:4 or HCLK PLL rate,
55 * while PCLK can be 1:1 to 1:32 of HCLK PLL rate. Most peripherals high
56 * level clocks are based on either HCLK or PCLK, but have their own
57 * dividers as part of the IP itself. Because of this, the system clock
58 * rates should not be changed.
59 *
60 * The HCLK PLL is clocked from SYSCLK, which can be derived from the
61 * main oscillator or PLL397. PLL397 generates a rate that is 397 times
62 * the 32KHz oscillator rate. The main oscillator runs at the selected
63 * oscillator/crystal rate on the mosc_in pin of the LPC32xx. This rate
64 * is normally 13MHz, but depends on the selection of external crystals
65 * or oscillators. If USB operation is required, the main oscillator must
66 * be used in the system.
67 *
68 * Switching SYSCLK between sources during normal Linux operation is not
69 * supported. SYSCLK is preset in the bootloader. Because of the
70 * complexities of clock management during clock frequency changes,
71 * there are some limitations to the clock driver explained below:
72 * - The PLL397 and main oscillator can be enabled and disabled by the
73 * clk_enable() and clk_disable() functions unless SYSCLK is based
74 * on that clock. This allows the other oscillator that isn't driving
75 * the HCLK PLL to be used as another system clock that can be routed
76 * to an external pin.
77 * - The muxed SYSCLK input and HCLK_PLL rate cannot be changed with
78 * this driver.
79 * - HCLK and PCLK rates cannot be changed as part of this driver.
80 * - Most peripherals have their own dividers are part of the peripheral
81 * block. Changing SYSCLK, HCLK PLL, HCLK, or PCLK sources or rates
82 * will also impact the individual peripheral rates.
83 */
84
85 #include <linux/export.h>
86 #include <linux/kernel.h>
87 #include <linux/list.h>
88 #include <linux/errno.h>
89 #include <linux/device.h>
90 #include <linux/delay.h>
91 #include <linux/err.h>
92 #include <linux/clk.h>
93 #include <linux/amba/bus.h>
94 #include <linux/amba/clcd.h>
95 #include <linux/clkdev.h>
96
97 #include <mach/hardware.h>
98 #include <mach/platform.h>
99 #include "clock.h"
100 #include "common.h"
101
102 static DEFINE_SPINLOCK(global_clkregs_lock);
103
104 static int usb_pll_enable, usb_pll_valid;
105
106 static struct clk clk_armpll;
107 static struct clk clk_usbpll;
108
109 /*
110 * Post divider values for PLLs based on selected register value
111 */
112 static const u32 pll_postdivs[4] = {1, 2, 4, 8};
113
local_return_parent_rate(struct clk * clk)114 static unsigned long local_return_parent_rate(struct clk *clk)
115 {
116 /*
117 * If a clock has a rate of 0, then it inherits it's parent
118 * clock rate
119 */
120 while (clk->rate == 0)
121 clk = clk->parent;
122
123 return clk->rate;
124 }
125
126 /* 32KHz clock has a fixed rate and is not stoppable */
127 static struct clk osc_32KHz = {
128 .rate = LPC32XX_CLOCK_OSC_FREQ,
129 .get_rate = local_return_parent_rate,
130 };
131
local_pll397_enable(struct clk * clk,int enable)132 static int local_pll397_enable(struct clk *clk, int enable)
133 {
134 u32 reg;
135 unsigned long timeout = jiffies + msecs_to_jiffies(10);
136
137 reg = __raw_readl(LPC32XX_CLKPWR_PLL397_CTRL);
138
139 if (enable == 0) {
140 reg |= LPC32XX_CLKPWR_SYSCTRL_PLL397_DIS;
141 __raw_writel(reg, LPC32XX_CLKPWR_PLL397_CTRL);
142 } else {
143 /* Enable PLL397 */
144 reg &= ~LPC32XX_CLKPWR_SYSCTRL_PLL397_DIS;
145 __raw_writel(reg, LPC32XX_CLKPWR_PLL397_CTRL);
146
147 /* Wait for PLL397 lock */
148 while (((__raw_readl(LPC32XX_CLKPWR_PLL397_CTRL) &
149 LPC32XX_CLKPWR_SYSCTRL_PLL397_STS) == 0) &&
150 time_before(jiffies, timeout))
151 cpu_relax();
152
153 if ((__raw_readl(LPC32XX_CLKPWR_PLL397_CTRL) &
154 LPC32XX_CLKPWR_SYSCTRL_PLL397_STS) == 0)
155 return -ENODEV;
156 }
157
158 return 0;
159 }
160
local_oscmain_enable(struct clk * clk,int enable)161 static int local_oscmain_enable(struct clk *clk, int enable)
162 {
163 u32 reg;
164 unsigned long timeout = jiffies + msecs_to_jiffies(10);
165
166 reg = __raw_readl(LPC32XX_CLKPWR_MAIN_OSC_CTRL);
167
168 if (enable == 0) {
169 reg |= LPC32XX_CLKPWR_MOSC_DISABLE;
170 __raw_writel(reg, LPC32XX_CLKPWR_MAIN_OSC_CTRL);
171 } else {
172 /* Enable main oscillator */
173 reg &= ~LPC32XX_CLKPWR_MOSC_DISABLE;
174 __raw_writel(reg, LPC32XX_CLKPWR_MAIN_OSC_CTRL);
175
176 /* Wait for main oscillator to start */
177 while (((__raw_readl(LPC32XX_CLKPWR_MAIN_OSC_CTRL) &
178 LPC32XX_CLKPWR_MOSC_DISABLE) != 0) &&
179 time_before(jiffies, timeout))
180 cpu_relax();
181
182 if ((__raw_readl(LPC32XX_CLKPWR_MAIN_OSC_CTRL) &
183 LPC32XX_CLKPWR_MOSC_DISABLE) != 0)
184 return -ENODEV;
185 }
186
187 return 0;
188 }
189
190 static struct clk osc_pll397 = {
191 .parent = &osc_32KHz,
192 .enable = local_pll397_enable,
193 .rate = LPC32XX_CLOCK_OSC_FREQ * 397,
194 .get_rate = local_return_parent_rate,
195 };
196
197 static struct clk osc_main = {
198 .enable = local_oscmain_enable,
199 .rate = LPC32XX_MAIN_OSC_FREQ,
200 .get_rate = local_return_parent_rate,
201 };
202
203 static struct clk clk_sys;
204
205 /*
206 * Convert a PLL register value to a PLL output frequency
207 */
clk_get_pllrate_from_reg(u32 inputclk,u32 regval)208 u32 clk_get_pllrate_from_reg(u32 inputclk, u32 regval)
209 {
210 struct clk_pll_setup pllcfg;
211
212 pllcfg.cco_bypass_b15 = 0;
213 pllcfg.direct_output_b14 = 0;
214 pllcfg.fdbk_div_ctrl_b13 = 0;
215 if ((regval & LPC32XX_CLKPWR_HCLKPLL_CCO_BYPASS) != 0)
216 pllcfg.cco_bypass_b15 = 1;
217 if ((regval & LPC32XX_CLKPWR_HCLKPLL_POSTDIV_BYPASS) != 0)
218 pllcfg.direct_output_b14 = 1;
219 if ((regval & LPC32XX_CLKPWR_HCLKPLL_FDBK_SEL_FCLK) != 0)
220 pllcfg.fdbk_div_ctrl_b13 = 1;
221 pllcfg.pll_m = 1 + ((regval >> 1) & 0xFF);
222 pllcfg.pll_n = 1 + ((regval >> 9) & 0x3);
223 pllcfg.pll_p = pll_postdivs[((regval >> 11) & 0x3)];
224
225 return clk_check_pll_setup(inputclk, &pllcfg);
226 }
227
228 /*
229 * Setup the HCLK PLL with a PLL structure
230 */
local_clk_pll_setup(struct clk_pll_setup * PllSetup)231 static u32 local_clk_pll_setup(struct clk_pll_setup *PllSetup)
232 {
233 u32 tv, tmp = 0;
234
235 if (PllSetup->analog_on != 0)
236 tmp |= LPC32XX_CLKPWR_HCLKPLL_POWER_UP;
237 if (PllSetup->cco_bypass_b15 != 0)
238 tmp |= LPC32XX_CLKPWR_HCLKPLL_CCO_BYPASS;
239 if (PllSetup->direct_output_b14 != 0)
240 tmp |= LPC32XX_CLKPWR_HCLKPLL_POSTDIV_BYPASS;
241 if (PllSetup->fdbk_div_ctrl_b13 != 0)
242 tmp |= LPC32XX_CLKPWR_HCLKPLL_FDBK_SEL_FCLK;
243
244 tv = ffs(PllSetup->pll_p) - 1;
245 if ((!is_power_of_2(PllSetup->pll_p)) || (tv > 3))
246 return 0;
247
248 tmp |= LPC32XX_CLKPWR_HCLKPLL_POSTDIV_2POW(tv);
249 tmp |= LPC32XX_CLKPWR_HCLKPLL_PREDIV_PLUS1(PllSetup->pll_n - 1);
250 tmp |= LPC32XX_CLKPWR_HCLKPLL_PLLM(PllSetup->pll_m - 1);
251
252 return tmp;
253 }
254
255 /*
256 * Update the ARM core PLL frequency rate variable from the actual PLL setting
257 */
local_update_armpll_rate(void)258 static void local_update_armpll_rate(void)
259 {
260 u32 clkin, pllreg;
261
262 clkin = clk_armpll.parent->rate;
263 pllreg = __raw_readl(LPC32XX_CLKPWR_HCLKPLL_CTRL) & 0x1FFFF;
264
265 clk_armpll.rate = clk_get_pllrate_from_reg(clkin, pllreg);
266 }
267
268 /*
269 * Find a PLL configuration for the selected input frequency
270 */
local_clk_find_pll_cfg(u32 pllin_freq,u32 target_freq,struct clk_pll_setup * pllsetup)271 static u32 local_clk_find_pll_cfg(u32 pllin_freq, u32 target_freq,
272 struct clk_pll_setup *pllsetup)
273 {
274 u32 ifreq, freqtol, m, n, p, fclkout;
275
276 /* Determine frequency tolerance limits */
277 freqtol = target_freq / 250;
278 ifreq = pllin_freq;
279
280 /* Is direct bypass mode possible? */
281 if (abs(pllin_freq - target_freq) <= freqtol) {
282 pllsetup->analog_on = 0;
283 pllsetup->cco_bypass_b15 = 1;
284 pllsetup->direct_output_b14 = 1;
285 pllsetup->fdbk_div_ctrl_b13 = 1;
286 pllsetup->pll_p = pll_postdivs[0];
287 pllsetup->pll_n = 1;
288 pllsetup->pll_m = 1;
289 return clk_check_pll_setup(ifreq, pllsetup);
290 } else if (target_freq <= ifreq) {
291 pllsetup->analog_on = 0;
292 pllsetup->cco_bypass_b15 = 1;
293 pllsetup->direct_output_b14 = 0;
294 pllsetup->fdbk_div_ctrl_b13 = 1;
295 pllsetup->pll_n = 1;
296 pllsetup->pll_m = 1;
297 for (p = 0; p <= 3; p++) {
298 pllsetup->pll_p = pll_postdivs[p];
299 fclkout = clk_check_pll_setup(ifreq, pllsetup);
300 if (abs(target_freq - fclkout) <= freqtol)
301 return fclkout;
302 }
303 }
304
305 /* Is direct mode possible? */
306 pllsetup->analog_on = 1;
307 pllsetup->cco_bypass_b15 = 0;
308 pllsetup->direct_output_b14 = 1;
309 pllsetup->fdbk_div_ctrl_b13 = 0;
310 pllsetup->pll_p = pll_postdivs[0];
311 for (m = 1; m <= 256; m++) {
312 for (n = 1; n <= 4; n++) {
313 /* Compute output frequency for this value */
314 pllsetup->pll_n = n;
315 pllsetup->pll_m = m;
316 fclkout = clk_check_pll_setup(ifreq,
317 pllsetup);
318 if (abs(target_freq - fclkout) <=
319 freqtol)
320 return fclkout;
321 }
322 }
323
324 /* Is integer mode possible? */
325 pllsetup->analog_on = 1;
326 pllsetup->cco_bypass_b15 = 0;
327 pllsetup->direct_output_b14 = 0;
328 pllsetup->fdbk_div_ctrl_b13 = 1;
329 for (m = 1; m <= 256; m++) {
330 for (n = 1; n <= 4; n++) {
331 for (p = 0; p < 4; p++) {
332 /* Compute output frequency */
333 pllsetup->pll_p = pll_postdivs[p];
334 pllsetup->pll_n = n;
335 pllsetup->pll_m = m;
336 fclkout = clk_check_pll_setup(
337 ifreq, pllsetup);
338 if (abs(target_freq - fclkout) <= freqtol)
339 return fclkout;
340 }
341 }
342 }
343
344 /* Try non-integer mode */
345 pllsetup->analog_on = 1;
346 pllsetup->cco_bypass_b15 = 0;
347 pllsetup->direct_output_b14 = 0;
348 pllsetup->fdbk_div_ctrl_b13 = 0;
349 for (m = 1; m <= 256; m++) {
350 for (n = 1; n <= 4; n++) {
351 for (p = 0; p < 4; p++) {
352 /* Compute output frequency */
353 pllsetup->pll_p = pll_postdivs[p];
354 pllsetup->pll_n = n;
355 pllsetup->pll_m = m;
356 fclkout = clk_check_pll_setup(
357 ifreq, pllsetup);
358 if (abs(target_freq - fclkout) <= freqtol)
359 return fclkout;
360 }
361 }
362 }
363
364 return 0;
365 }
366
367 static struct clk clk_armpll = {
368 .parent = &clk_sys,
369 .get_rate = local_return_parent_rate,
370 };
371
372 /*
373 * Setup the USB PLL with a PLL structure
374 */
local_clk_usbpll_setup(struct clk_pll_setup * pHCLKPllSetup)375 static u32 local_clk_usbpll_setup(struct clk_pll_setup *pHCLKPllSetup)
376 {
377 u32 reg, tmp = local_clk_pll_setup(pHCLKPllSetup);
378
379 reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL) & ~0x1FFFF;
380 reg |= tmp;
381 __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
382
383 return clk_check_pll_setup(clk_usbpll.parent->rate,
384 pHCLKPllSetup);
385 }
386
local_usbpll_enable(struct clk * clk,int enable)387 static int local_usbpll_enable(struct clk *clk, int enable)
388 {
389 u32 reg;
390 int ret = 0;
391 unsigned long timeout = jiffies + msecs_to_jiffies(20);
392
393 reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);
394
395 __raw_writel(reg & ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN2 |
396 LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP),
397 LPC32XX_CLKPWR_USB_CTRL);
398 __raw_writel(reg & ~LPC32XX_CLKPWR_USBCTRL_CLK_EN1,
399 LPC32XX_CLKPWR_USB_CTRL);
400
401 if (enable && usb_pll_valid && usb_pll_enable) {
402 ret = -ENODEV;
403 /*
404 * If the PLL rate has been previously set, then the rate
405 * in the PLL register is valid and can be enabled here.
406 * Otherwise, it needs to be enabled as part of setrate.
407 */
408
409 /*
410 * Gate clock into PLL
411 */
412 reg |= LPC32XX_CLKPWR_USBCTRL_CLK_EN1;
413 __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
414
415 /*
416 * Enable PLL
417 */
418 reg |= LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP;
419 __raw_writel(reg, LPC32XX_CLKPWR_USB_CTRL);
420
421 /*
422 * Wait for PLL to lock
423 */
424 while (time_before(jiffies, timeout) && (ret == -ENODEV)) {
425 reg = __raw_readl(LPC32XX_CLKPWR_USB_CTRL);
426 if (reg & LPC32XX_CLKPWR_USBCTRL_PLL_STS)
427 ret = 0;
428 else
429 udelay(10);
430 }
431
432 /*
433 * Gate clock from PLL if PLL is locked
434 */
435 if (ret == 0) {
436 __raw_writel(reg | LPC32XX_CLKPWR_USBCTRL_CLK_EN2,
437 LPC32XX_CLKPWR_USB_CTRL);
438 } else {
439 __raw_writel(reg & ~(LPC32XX_CLKPWR_USBCTRL_CLK_EN1 |
440 LPC32XX_CLKPWR_USBCTRL_PLL_PWRUP),
441 LPC32XX_CLKPWR_USB_CTRL);
442 }
443 } else if ((enable == 0) && usb_pll_valid && usb_pll_enable) {
444 usb_pll_valid = 0;
445 usb_pll_enable = 0;
446 }
447
448 return ret;
449 }
450
local_usbpll_round_rate(struct clk * clk,unsigned long rate)451 static unsigned long local_usbpll_round_rate(struct clk *clk,
452 unsigned long rate)
453 {
454 u32 clkin, usbdiv;
455 struct clk_pll_setup pllsetup;
456
457 /*
458 * Unlike other clocks, this clock has a KHz input rate, so bump
459 * it up to work with the PLL function
460 */
461 rate = rate * 1000;
462
463 clkin = clk->get_rate(clk);
464 usbdiv = (__raw_readl(LPC32XX_CLKPWR_USBCLK_PDIV) &
465 LPC32XX_CLKPWR_USBPDIV_PLL_MASK) + 1;
466 clkin = clkin / usbdiv;
467
468 /* Try to find a good rate setup */
469 if (local_clk_find_pll_cfg(clkin, rate, &pllsetup) == 0)
470 return 0;
471
472 return clk_check_pll_setup(clkin, &pllsetup);
473 }
474
local_usbpll_set_rate(struct clk * clk,unsigned long rate)475 static int local_usbpll_set_rate(struct clk *clk, unsigned long rate)
476 {
477 int ret = -ENODEV;
478 u32 clkin, usbdiv;
479 struct clk_pll_setup pllsetup;
480
481 /*
482 * Unlike other clocks, this clock has a KHz input rate, so bump
483 * it up to work with the PLL function
484 */
485 rate = rate * 1000;
486
487 clkin = clk->get_rate(clk->parent);
488 usbdiv = (__raw_readl(LPC32XX_CLKPWR_USBCLK_PDIV) &
489 LPC32XX_CLKPWR_USBPDIV_PLL_MASK) + 1;
490 clkin = clkin / usbdiv;
491
492 /* Try to find a good rate setup */
493 if (local_clk_find_pll_cfg(clkin, rate, &pllsetup) == 0)
494 return -EINVAL;
495
496 /*
497 * Disable PLL clocks during PLL change
498 */
499 local_usbpll_enable(clk, 0);
500 pllsetup.analog_on = 0;
501 local_clk_usbpll_setup(&pllsetup);
502
503 /*
504 * Start USB PLL and check PLL status
505 */
506
507 usb_pll_valid = 1;
508 usb_pll_enable = 1;
509
510 ret = local_usbpll_enable(clk, 1);
511 if (ret >= 0)
512 clk->rate = clk_check_pll_setup(clkin, &pllsetup);
513
514 return ret;
515 }
516
517 static struct clk clk_usbpll = {
518 .parent = &osc_main,
519 .set_rate = local_usbpll_set_rate,
520 .enable = local_usbpll_enable,
521 .rate = 48000, /* In KHz */
522 .get_rate = local_return_parent_rate,
523 .round_rate = local_usbpll_round_rate,
524 };
525
clk_get_hclk_div(void)526 static u32 clk_get_hclk_div(void)
527 {
528 static const u32 hclkdivs[4] = {1, 2, 4, 4};
529 return hclkdivs[LPC32XX_CLKPWR_HCLKDIV_DIV_2POW(
530 __raw_readl(LPC32XX_CLKPWR_HCLK_DIV))];
531 }
532
533 static struct clk clk_hclk = {
534 .parent = &clk_armpll,
535 .get_rate = local_return_parent_rate,
536 };
537
538 static struct clk clk_pclk = {
539 .parent = &clk_armpll,
540 .get_rate = local_return_parent_rate,
541 };
542
local_onoff_enable(struct clk * clk,int enable)543 static int local_onoff_enable(struct clk *clk, int enable)
544 {
545 u32 tmp;
546
547 tmp = __raw_readl(clk->enable_reg);
548
549 if (enable == 0)
550 tmp &= ~clk->enable_mask;
551 else
552 tmp |= clk->enable_mask;
553
554 __raw_writel(tmp, clk->enable_reg);
555
556 return 0;
557 }
558
559 /* Peripheral clock sources */
560 static struct clk clk_timer0 = {
561 .parent = &clk_pclk,
562 .enable = local_onoff_enable,
563 .enable_reg = LPC32XX_CLKPWR_TIMERS_PWMS_CLK_CTRL_1,
564 .enable_mask = LPC32XX_CLKPWR_TMRPWMCLK_TIMER0_EN,
565 .get_rate = local_return_parent_rate,
566 };
567 static struct clk clk_timer1 = {
568 .parent = &clk_pclk,
569 .enable = local_onoff_enable,
570 .enable_reg = LPC32XX_CLKPWR_TIMERS_PWMS_CLK_CTRL_1,
571 .enable_mask = LPC32XX_CLKPWR_TMRPWMCLK_TIMER1_EN,
572 .get_rate = local_return_parent_rate,
573 };
574 static struct clk clk_timer2 = {
575 .parent = &clk_pclk,
576 .enable = local_onoff_enable,
577 .enable_reg = LPC32XX_CLKPWR_TIMERS_PWMS_CLK_CTRL_1,
578 .enable_mask = LPC32XX_CLKPWR_TMRPWMCLK_TIMER2_EN,
579 .get_rate = local_return_parent_rate,
580 };
581 static struct clk clk_timer3 = {
582 .parent = &clk_pclk,
583 .enable = local_onoff_enable,
584 .enable_reg = LPC32XX_CLKPWR_TIMERS_PWMS_CLK_CTRL_1,
585 .enable_mask = LPC32XX_CLKPWR_TMRPWMCLK_TIMER3_EN,
586 .get_rate = local_return_parent_rate,
587 };
588 static struct clk clk_wdt = {
589 .parent = &clk_pclk,
590 .enable = local_onoff_enable,
591 .enable_reg = LPC32XX_CLKPWR_TIMER_CLK_CTRL,
592 .enable_mask = LPC32XX_CLKPWR_PWMCLK_WDOG_EN,
593 .get_rate = local_return_parent_rate,
594 };
595 static struct clk clk_vfp9 = {
596 .parent = &clk_pclk,
597 .enable = local_onoff_enable,
598 .enable_reg = LPC32XX_CLKPWR_DEBUG_CTRL,
599 .enable_mask = LPC32XX_CLKPWR_VFP_CLOCK_ENABLE_BIT,
600 .get_rate = local_return_parent_rate,
601 };
602 static struct clk clk_dma = {
603 .parent = &clk_hclk,
604 .enable = local_onoff_enable,
605 .enable_reg = LPC32XX_CLKPWR_DMA_CLK_CTRL,
606 .enable_mask = LPC32XX_CLKPWR_DMACLKCTRL_CLK_EN,
607 .get_rate = local_return_parent_rate,
608 };
609
610 static struct clk clk_uart3 = {
611 .parent = &clk_pclk,
612 .enable = local_onoff_enable,
613 .enable_reg = LPC32XX_CLKPWR_UART_CLK_CTRL,
614 .enable_mask = LPC32XX_CLKPWR_UARTCLKCTRL_UART3_EN,
615 .get_rate = local_return_parent_rate,
616 };
617
618 static struct clk clk_uart4 = {
619 .parent = &clk_pclk,
620 .enable = local_onoff_enable,
621 .enable_reg = LPC32XX_CLKPWR_UART_CLK_CTRL,
622 .enable_mask = LPC32XX_CLKPWR_UARTCLKCTRL_UART4_EN,
623 .get_rate = local_return_parent_rate,
624 };
625
626 static struct clk clk_uart5 = {
627 .parent = &clk_pclk,
628 .enable = local_onoff_enable,
629 .enable_reg = LPC32XX_CLKPWR_UART_CLK_CTRL,
630 .enable_mask = LPC32XX_CLKPWR_UARTCLKCTRL_UART5_EN,
631 .get_rate = local_return_parent_rate,
632 };
633
634 static struct clk clk_uart6 = {
635 .parent = &clk_pclk,
636 .enable = local_onoff_enable,
637 .enable_reg = LPC32XX_CLKPWR_UART_CLK_CTRL,
638 .enable_mask = LPC32XX_CLKPWR_UARTCLKCTRL_UART6_EN,
639 .get_rate = local_return_parent_rate,
640 };
641
642 static struct clk clk_i2c0 = {
643 .parent = &clk_hclk,
644 .enable = local_onoff_enable,
645 .enable_reg = LPC32XX_CLKPWR_I2C_CLK_CTRL,
646 .enable_mask = LPC32XX_CLKPWR_I2CCLK_I2C1CLK_EN,
647 .get_rate = local_return_parent_rate,
648 };
649
650 static struct clk clk_i2c1 = {
651 .parent = &clk_hclk,
652 .enable = local_onoff_enable,
653 .enable_reg = LPC32XX_CLKPWR_I2C_CLK_CTRL,
654 .enable_mask = LPC32XX_CLKPWR_I2CCLK_I2C2CLK_EN,
655 .get_rate = local_return_parent_rate,
656 };
657
658 static struct clk clk_i2c2 = {
659 .parent = &clk_pclk,
660 .enable = local_onoff_enable,
661 .enable_reg = io_p2v(LPC32XX_USB_BASE + 0xFF4),
662 .enable_mask = 0x4,
663 .get_rate = local_return_parent_rate,
664 };
665
666 static struct clk clk_ssp0 = {
667 .parent = &clk_hclk,
668 .enable = local_onoff_enable,
669 .enable_reg = LPC32XX_CLKPWR_SSP_CLK_CTRL,
670 .enable_mask = LPC32XX_CLKPWR_SSPCTRL_SSPCLK0_EN,
671 .get_rate = local_return_parent_rate,
672 };
673
674 static struct clk clk_ssp1 = {
675 .parent = &clk_hclk,
676 .enable = local_onoff_enable,
677 .enable_reg = LPC32XX_CLKPWR_SSP_CLK_CTRL,
678 .enable_mask = LPC32XX_CLKPWR_SSPCTRL_SSPCLK1_EN,
679 .get_rate = local_return_parent_rate,
680 };
681
682 static struct clk clk_kscan = {
683 .parent = &osc_32KHz,
684 .enable = local_onoff_enable,
685 .enable_reg = LPC32XX_CLKPWR_KEY_CLK_CTRL,
686 .enable_mask = LPC32XX_CLKPWR_KEYCLKCTRL_CLK_EN,
687 .get_rate = local_return_parent_rate,
688 };
689
690 static struct clk clk_nand = {
691 .parent = &clk_hclk,
692 .enable = local_onoff_enable,
693 .enable_reg = LPC32XX_CLKPWR_NAND_CLK_CTRL,
694 .enable_mask = LPC32XX_CLKPWR_NANDCLK_SLCCLK_EN,
695 .get_rate = local_return_parent_rate,
696 };
697
698 static struct clk clk_i2s0 = {
699 .parent = &clk_hclk,
700 .enable = local_onoff_enable,
701 .enable_reg = LPC32XX_CLKPWR_I2S_CLK_CTRL,
702 .enable_mask = LPC32XX_CLKPWR_I2SCTRL_I2SCLK0_EN,
703 .get_rate = local_return_parent_rate,
704 };
705
706 static struct clk clk_i2s1 = {
707 .parent = &clk_hclk,
708 .enable = local_onoff_enable,
709 .enable_reg = LPC32XX_CLKPWR_I2S_CLK_CTRL,
710 .enable_mask = LPC32XX_CLKPWR_I2SCTRL_I2SCLK1_EN,
711 .get_rate = local_return_parent_rate,
712 };
713
714 static struct clk clk_net = {
715 .parent = &clk_hclk,
716 .enable = local_onoff_enable,
717 .enable_reg = LPC32XX_CLKPWR_MACCLK_CTRL,
718 .enable_mask = (LPC32XX_CLKPWR_MACCTRL_DMACLK_EN |
719 LPC32XX_CLKPWR_MACCTRL_MMIOCLK_EN |
720 LPC32XX_CLKPWR_MACCTRL_HRCCLK_EN),
721 .get_rate = local_return_parent_rate,
722 };
723
724 static struct clk clk_rtc = {
725 .parent = &osc_32KHz,
726 .rate = 1, /* 1 Hz */
727 .get_rate = local_return_parent_rate,
728 };
729
730 static struct clk clk_usbd = {
731 .parent = &clk_usbpll,
732 .enable = local_onoff_enable,
733 .enable_reg = LPC32XX_CLKPWR_USB_CTRL,
734 .enable_mask = LPC32XX_CLKPWR_USBCTRL_HCLK_EN,
735 .get_rate = local_return_parent_rate,
736 };
737
tsc_onoff_enable(struct clk * clk,int enable)738 static int tsc_onoff_enable(struct clk *clk, int enable)
739 {
740 u32 tmp;
741
742 /* Make sure 32KHz clock is the selected clock */
743 tmp = __raw_readl(LPC32XX_CLKPWR_ADC_CLK_CTRL_1);
744 tmp &= ~LPC32XX_CLKPWR_ADCCTRL1_PCLK_SEL;
745 __raw_writel(tmp, LPC32XX_CLKPWR_ADC_CLK_CTRL_1);
746
747 if (enable == 0)
748 __raw_writel(0, clk->enable_reg);
749 else
750 __raw_writel(clk->enable_mask, clk->enable_reg);
751
752 return 0;
753 }
754
755 static struct clk clk_tsc = {
756 .parent = &osc_32KHz,
757 .enable = tsc_onoff_enable,
758 .enable_reg = LPC32XX_CLKPWR_ADC_CLK_CTRL,
759 .enable_mask = LPC32XX_CLKPWR_ADC32CLKCTRL_CLK_EN,
760 .get_rate = local_return_parent_rate,
761 };
762
adc_onoff_enable(struct clk * clk,int enable)763 static int adc_onoff_enable(struct clk *clk, int enable)
764 {
765 u32 tmp;
766 u32 divider;
767
768 /* Use PERIPH_CLOCK */
769 tmp = __raw_readl(LPC32XX_CLKPWR_ADC_CLK_CTRL_1);
770 tmp |= LPC32XX_CLKPWR_ADCCTRL1_PCLK_SEL;
771 /*
772 * Set clock divider so that we have equal to or less than
773 * 4.5MHz clock at ADC
774 */
775 divider = clk->get_rate(clk) / 4500000 + 1;
776 tmp |= divider;
777 __raw_writel(tmp, LPC32XX_CLKPWR_ADC_CLK_CTRL_1);
778
779 /* synchronize rate of this clock w/ actual HW setting */
780 clk->rate = clk->get_rate(clk->parent) / divider;
781
782 if (enable == 0)
783 __raw_writel(0, clk->enable_reg);
784 else
785 __raw_writel(clk->enable_mask, clk->enable_reg);
786
787 return 0;
788 }
789
790 static struct clk clk_adc = {
791 .parent = &clk_pclk,
792 .enable = adc_onoff_enable,
793 .enable_reg = LPC32XX_CLKPWR_ADC_CLK_CTRL,
794 .enable_mask = LPC32XX_CLKPWR_ADC32CLKCTRL_CLK_EN,
795 .get_rate = local_return_parent_rate,
796 };
797
mmc_onoff_enable(struct clk * clk,int enable)798 static int mmc_onoff_enable(struct clk *clk, int enable)
799 {
800 u32 tmp;
801
802 tmp = __raw_readl(LPC32XX_CLKPWR_MS_CTRL) &
803 ~LPC32XX_CLKPWR_MSCARD_SDCARD_EN;
804
805 /* If rate is 0, disable clock */
806 if (enable != 0)
807 tmp |= LPC32XX_CLKPWR_MSCARD_SDCARD_EN;
808
809 __raw_writel(tmp, LPC32XX_CLKPWR_MS_CTRL);
810
811 return 0;
812 }
813
mmc_get_rate(struct clk * clk)814 static unsigned long mmc_get_rate(struct clk *clk)
815 {
816 u32 div, rate, oldclk;
817
818 /* The MMC clock must be on when accessing an MMC register */
819 oldclk = __raw_readl(LPC32XX_CLKPWR_MS_CTRL);
820 __raw_writel(oldclk | LPC32XX_CLKPWR_MSCARD_SDCARD_EN,
821 LPC32XX_CLKPWR_MS_CTRL);
822 div = __raw_readl(LPC32XX_CLKPWR_MS_CTRL);
823 __raw_writel(oldclk, LPC32XX_CLKPWR_MS_CTRL);
824
825 /* Get the parent clock rate */
826 rate = clk->parent->get_rate(clk->parent);
827
828 /* Get the MMC controller clock divider value */
829 div = div & LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(0xf);
830
831 if (!div)
832 div = 1;
833
834 return rate / div;
835 }
836
mmc_round_rate(struct clk * clk,unsigned long rate)837 static unsigned long mmc_round_rate(struct clk *clk, unsigned long rate)
838 {
839 unsigned long div, prate;
840
841 /* Get the parent clock rate */
842 prate = clk->parent->get_rate(clk->parent);
843
844 if (rate >= prate)
845 return prate;
846
847 div = prate / rate;
848 if (div > 0xf)
849 div = 0xf;
850
851 return prate / div;
852 }
853
mmc_set_rate(struct clk * clk,unsigned long rate)854 static int mmc_set_rate(struct clk *clk, unsigned long rate)
855 {
856 u32 oldclk, tmp;
857 unsigned long prate, div, crate = mmc_round_rate(clk, rate);
858
859 prate = clk->parent->get_rate(clk->parent);
860
861 div = prate / crate;
862
863 /* The MMC clock must be on when accessing an MMC register */
864 oldclk = __raw_readl(LPC32XX_CLKPWR_MS_CTRL);
865 __raw_writel(oldclk | LPC32XX_CLKPWR_MSCARD_SDCARD_EN,
866 LPC32XX_CLKPWR_MS_CTRL);
867 tmp = __raw_readl(LPC32XX_CLKPWR_MS_CTRL) &
868 ~LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(0xf);
869 tmp |= LPC32XX_CLKPWR_MSCARD_SDCARD_DIV(div);
870 __raw_writel(tmp, LPC32XX_CLKPWR_MS_CTRL);
871
872 __raw_writel(oldclk, LPC32XX_CLKPWR_MS_CTRL);
873
874 return 0;
875 }
876
877 static struct clk clk_mmc = {
878 .parent = &clk_armpll,
879 .set_rate = mmc_set_rate,
880 .get_rate = mmc_get_rate,
881 .round_rate = mmc_round_rate,
882 .enable = mmc_onoff_enable,
883 .enable_reg = LPC32XX_CLKPWR_MS_CTRL,
884 .enable_mask = LPC32XX_CLKPWR_MSCARD_SDCARD_EN,
885 };
886
clcd_get_rate(struct clk * clk)887 static unsigned long clcd_get_rate(struct clk *clk)
888 {
889 u32 tmp, div, rate, oldclk;
890
891 /* The LCD clock must be on when accessing an LCD register */
892 oldclk = __raw_readl(LPC32XX_CLKPWR_LCDCLK_CTRL);
893 __raw_writel(oldclk | LPC32XX_CLKPWR_LCDCTRL_CLK_EN,
894 LPC32XX_CLKPWR_LCDCLK_CTRL);
895 tmp = __raw_readl(io_p2v(LPC32XX_LCD_BASE + CLCD_TIM2));
896 __raw_writel(oldclk, LPC32XX_CLKPWR_LCDCLK_CTRL);
897
898 rate = clk->parent->get_rate(clk->parent);
899
900 /* Only supports internal clocking */
901 if (tmp & TIM2_BCD)
902 return rate;
903
904 div = (tmp & 0x1F) | ((tmp & 0xF8) >> 22);
905 tmp = rate / (2 + div);
906
907 return tmp;
908 }
909
clcd_set_rate(struct clk * clk,unsigned long rate)910 static int clcd_set_rate(struct clk *clk, unsigned long rate)
911 {
912 u32 tmp, prate, div, oldclk;
913
914 /* The LCD clock must be on when accessing an LCD register */
915 oldclk = __raw_readl(LPC32XX_CLKPWR_LCDCLK_CTRL);
916 __raw_writel(oldclk | LPC32XX_CLKPWR_LCDCTRL_CLK_EN,
917 LPC32XX_CLKPWR_LCDCLK_CTRL);
918
919 tmp = __raw_readl(io_p2v(LPC32XX_LCD_BASE + CLCD_TIM2)) | TIM2_BCD;
920 prate = clk->parent->get_rate(clk->parent);
921
922 if (rate < prate) {
923 /* Find closest divider */
924 div = prate / rate;
925 if (div >= 2) {
926 div -= 2;
927 tmp &= ~TIM2_BCD;
928 }
929
930 tmp &= ~(0xF800001F);
931 tmp |= (div & 0x1F);
932 tmp |= (((div >> 5) & 0x1F) << 27);
933 }
934
935 __raw_writel(tmp, io_p2v(LPC32XX_LCD_BASE + CLCD_TIM2));
936 __raw_writel(oldclk, LPC32XX_CLKPWR_LCDCLK_CTRL);
937
938 return 0;
939 }
940
clcd_round_rate(struct clk * clk,unsigned long rate)941 static unsigned long clcd_round_rate(struct clk *clk, unsigned long rate)
942 {
943 u32 prate, div;
944
945 prate = clk->parent->get_rate(clk->parent);
946
947 if (rate >= prate)
948 rate = prate;
949 else {
950 div = prate / rate;
951 if (div > 0x3ff)
952 div = 0x3ff;
953
954 rate = prate / div;
955 }
956
957 return rate;
958 }
959
960 static struct clk clk_lcd = {
961 .parent = &clk_hclk,
962 .set_rate = clcd_set_rate,
963 .get_rate = clcd_get_rate,
964 .round_rate = clcd_round_rate,
965 .enable = local_onoff_enable,
966 .enable_reg = LPC32XX_CLKPWR_LCDCLK_CTRL,
967 .enable_mask = LPC32XX_CLKPWR_LCDCTRL_CLK_EN,
968 };
969
local_clk_disable(struct clk * clk)970 static void local_clk_disable(struct clk *clk)
971 {
972 /* Don't attempt to disable clock if it has no users */
973 if (clk->usecount > 0) {
974 clk->usecount--;
975
976 /* Only disable clock when it has no more users */
977 if ((clk->usecount == 0) && (clk->enable))
978 clk->enable(clk, 0);
979
980 /* Check parent clocks, they may need to be disabled too */
981 if (clk->parent)
982 local_clk_disable(clk->parent);
983 }
984 }
985
local_clk_enable(struct clk * clk)986 static int local_clk_enable(struct clk *clk)
987 {
988 int ret = 0;
989
990 /* Enable parent clocks first and update use counts */
991 if (clk->parent)
992 ret = local_clk_enable(clk->parent);
993
994 if (!ret) {
995 /* Only enable clock if it's currently disabled */
996 if ((clk->usecount == 0) && (clk->enable))
997 ret = clk->enable(clk, 1);
998
999 if (!ret)
1000 clk->usecount++;
1001 else if (clk->parent)
1002 local_clk_disable(clk->parent);
1003 }
1004
1005 return ret;
1006 }
1007
1008 /*
1009 * clk_enable - inform the system when the clock source should be running.
1010 */
clk_enable(struct clk * clk)1011 int clk_enable(struct clk *clk)
1012 {
1013 int ret;
1014 unsigned long flags;
1015
1016 spin_lock_irqsave(&global_clkregs_lock, flags);
1017 ret = local_clk_enable(clk);
1018 spin_unlock_irqrestore(&global_clkregs_lock, flags);
1019
1020 return ret;
1021 }
1022 EXPORT_SYMBOL(clk_enable);
1023
1024 /*
1025 * clk_disable - inform the system when the clock source is no longer required
1026 */
clk_disable(struct clk * clk)1027 void clk_disable(struct clk *clk)
1028 {
1029 unsigned long flags;
1030
1031 spin_lock_irqsave(&global_clkregs_lock, flags);
1032 local_clk_disable(clk);
1033 spin_unlock_irqrestore(&global_clkregs_lock, flags);
1034 }
1035 EXPORT_SYMBOL(clk_disable);
1036
1037 /*
1038 * clk_get_rate - obtain the current clock rate (in Hz) for a clock source
1039 */
clk_get_rate(struct clk * clk)1040 unsigned long clk_get_rate(struct clk *clk)
1041 {
1042 return clk->get_rate(clk);
1043 }
1044 EXPORT_SYMBOL(clk_get_rate);
1045
1046 /*
1047 * clk_set_rate - set the clock rate for a clock source
1048 */
clk_set_rate(struct clk * clk,unsigned long rate)1049 int clk_set_rate(struct clk *clk, unsigned long rate)
1050 {
1051 int ret = -EINVAL;
1052
1053 /*
1054 * Most system clocks can only be enabled or disabled, with
1055 * the actual rate set as part of the peripheral dividers
1056 * instead of high level clock control
1057 */
1058 if (clk->set_rate)
1059 ret = clk->set_rate(clk, rate);
1060
1061 return ret;
1062 }
1063 EXPORT_SYMBOL(clk_set_rate);
1064
1065 /*
1066 * clk_round_rate - adjust a rate to the exact rate a clock can provide
1067 */
clk_round_rate(struct clk * clk,unsigned long rate)1068 long clk_round_rate(struct clk *clk, unsigned long rate)
1069 {
1070 if (clk->round_rate)
1071 rate = clk->round_rate(clk, rate);
1072 else
1073 rate = clk->get_rate(clk);
1074
1075 return rate;
1076 }
1077 EXPORT_SYMBOL(clk_round_rate);
1078
1079 /*
1080 * clk_set_parent - set the parent clock source for this clock
1081 */
clk_set_parent(struct clk * clk,struct clk * parent)1082 int clk_set_parent(struct clk *clk, struct clk *parent)
1083 {
1084 /* Clock re-parenting is not supported */
1085 return -EINVAL;
1086 }
1087 EXPORT_SYMBOL(clk_set_parent);
1088
1089 /*
1090 * clk_get_parent - get the parent clock source for this clock
1091 */
clk_get_parent(struct clk * clk)1092 struct clk *clk_get_parent(struct clk *clk)
1093 {
1094 return clk->parent;
1095 }
1096 EXPORT_SYMBOL(clk_get_parent);
1097
1098 #define _REGISTER_CLOCK(d, n, c) \
1099 { \
1100 .dev_id = (d), \
1101 .con_id = (n), \
1102 .clk = &(c), \
1103 },
1104
1105 static struct clk_lookup lookups[] = {
1106 _REGISTER_CLOCK(NULL, "osc_32KHz", osc_32KHz)
1107 _REGISTER_CLOCK(NULL, "osc_pll397", osc_pll397)
1108 _REGISTER_CLOCK(NULL, "osc_main", osc_main)
1109 _REGISTER_CLOCK(NULL, "sys_ck", clk_sys)
1110 _REGISTER_CLOCK(NULL, "arm_pll_ck", clk_armpll)
1111 _REGISTER_CLOCK(NULL, "ck_pll5", clk_usbpll)
1112 _REGISTER_CLOCK(NULL, "hclk_ck", clk_hclk)
1113 _REGISTER_CLOCK(NULL, "pclk_ck", clk_pclk)
1114 _REGISTER_CLOCK(NULL, "timer0_ck", clk_timer0)
1115 _REGISTER_CLOCK(NULL, "timer1_ck", clk_timer1)
1116 _REGISTER_CLOCK(NULL, "timer2_ck", clk_timer2)
1117 _REGISTER_CLOCK(NULL, "timer3_ck", clk_timer3)
1118 _REGISTER_CLOCK(NULL, "vfp9_ck", clk_vfp9)
1119 _REGISTER_CLOCK(NULL, "clk_dmac", clk_dma)
1120 _REGISTER_CLOCK("pnx4008-watchdog", NULL, clk_wdt)
1121 _REGISTER_CLOCK(NULL, "uart3_ck", clk_uart3)
1122 _REGISTER_CLOCK(NULL, "uart4_ck", clk_uart4)
1123 _REGISTER_CLOCK(NULL, "uart5_ck", clk_uart5)
1124 _REGISTER_CLOCK(NULL, "uart6_ck", clk_uart6)
1125 _REGISTER_CLOCK("pnx-i2c.0", NULL, clk_i2c0)
1126 _REGISTER_CLOCK("pnx-i2c.1", NULL, clk_i2c1)
1127 _REGISTER_CLOCK("pnx-i2c.2", NULL, clk_i2c2)
1128 _REGISTER_CLOCK("dev:ssp0", NULL, clk_ssp0)
1129 _REGISTER_CLOCK("dev:ssp1", NULL, clk_ssp1)
1130 _REGISTER_CLOCK("lpc32xx_keys.0", NULL, clk_kscan)
1131 _REGISTER_CLOCK("lpc32xx-nand.0", "nand_ck", clk_nand)
1132 _REGISTER_CLOCK("lpc32xx-adc", NULL, clk_adc)
1133 _REGISTER_CLOCK(NULL, "i2s0_ck", clk_i2s0)
1134 _REGISTER_CLOCK(NULL, "i2s1_ck", clk_i2s1)
1135 _REGISTER_CLOCK("ts-lpc32xx", NULL, clk_tsc)
1136 _REGISTER_CLOCK("dev:mmc0", NULL, clk_mmc)
1137 _REGISTER_CLOCK("lpc-eth.0", NULL, clk_net)
1138 _REGISTER_CLOCK("dev:clcd", NULL, clk_lcd)
1139 _REGISTER_CLOCK("lpc32xx_udc", "ck_usbd", clk_usbd)
1140 _REGISTER_CLOCK("lpc32xx_rtc", NULL, clk_rtc)
1141 };
1142
clk_init(void)1143 static int __init clk_init(void)
1144 {
1145 int i;
1146
1147 for (i = 0; i < ARRAY_SIZE(lookups); i++)
1148 clkdev_add(&lookups[i]);
1149
1150 /*
1151 * Setup muxed SYSCLK for HCLK PLL base -this selects the
1152 * parent clock used for the ARM PLL and is used to derive
1153 * the many system clock rates in the device.
1154 */
1155 if (clk_is_sysclk_mainosc() != 0)
1156 clk_sys.parent = &osc_main;
1157 else
1158 clk_sys.parent = &osc_pll397;
1159
1160 clk_sys.rate = clk_sys.parent->rate;
1161
1162 /* Compute the current ARM PLL and USB PLL frequencies */
1163 local_update_armpll_rate();
1164
1165 /* Compute HCLK and PCLK bus rates */
1166 clk_hclk.rate = clk_hclk.parent->rate / clk_get_hclk_div();
1167 clk_pclk.rate = clk_pclk.parent->rate / clk_get_pclk_div();
1168
1169 /*
1170 * Enable system clocks - this step is somewhat formal, as the
1171 * clocks are already running, but it does get the clock data
1172 * inline with the actual system state. Never disable these
1173 * clocks as they will only stop if the system is going to sleep.
1174 * In that case, the chip/system power management functions will
1175 * handle clock gating.
1176 */
1177 if (clk_enable(&clk_hclk) || clk_enable(&clk_pclk))
1178 printk(KERN_ERR "Error enabling system HCLK and PCLK\n");
1179
1180 /*
1181 * Timers 0 and 1 were enabled and are being used by the high
1182 * resolution tick function prior to this driver being initialized.
1183 * Tag them now as used.
1184 */
1185 if (clk_enable(&clk_timer0) || clk_enable(&clk_timer1))
1186 printk(KERN_ERR "Error enabling timer tick clocks\n");
1187
1188 return 0;
1189 }
1190 core_initcall(clk_init);
1191
1192