2 * OMAP3-specific clock framework functions
4 * Copyright (C) 2007-2008 Texas Instruments, Inc.
5 * Copyright (C) 2007-2008 Nokia Corporation
7 * Written by Paul Walmsley
8 * Testing and integration fixes by Jouni Högander
10 * Parts of this code are based on code written by
11 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License version 2 as
15 * published by the Free Software Foundation.
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/device.h>
22 #include <linux/list.h>
23 #include <linux/errno.h>
24 #include <linux/delay.h>
25 #include <linux/clk.h>
27 #include <linux/limits.h>
28 #include <linux/bitops.h>
30 #include <mach/clock.h>
31 #include <mach/sram.h>
32 #include <asm/div64.h>
36 #include "clock34xx.h"
38 #include "prm-regbits-34xx.h"
40 #include "cm-regbits-34xx.h"
42 /* CM_AUTOIDLE_PLL*.AUTO_* bit values */
43 #define DPLL_AUTOIDLE_DISABLE 0x0
44 #define DPLL_AUTOIDLE_LOW_POWER_STOP 0x1
46 #define MAX_DPLL_WAIT_TRIES 1000000
49 * omap3_dpll_recalc - recalculate DPLL rate
50 * @clk: DPLL struct clk
52 * Recalculate and propagate the DPLL rate.
54 static void omap3_dpll_recalc(struct clk *clk)
56 clk->rate = omap2_get_dpll_rate(clk);
61 /* _omap3_dpll_write_clken - write clken_bits arg to a DPLL's enable bits */
62 static void _omap3_dpll_write_clken(struct clk *clk, u8 clken_bits)
64 const struct dpll_data *dd;
69 v = __raw_readl(dd->control_reg);
70 v &= ~dd->enable_mask;
71 v |= clken_bits << __ffs(dd->enable_mask);
72 __raw_writel(v, dd->control_reg);
75 /* _omap3_wait_dpll_status: wait for a DPLL to enter a specific state */
76 static int _omap3_wait_dpll_status(struct clk *clk, u8 state)
78 const struct dpll_data *dd;
85 state <<= dd->idlest_bit;
86 idlest_mask = 1 << dd->idlest_bit;
88 while (((__raw_readl(dd->idlest_reg) & idlest_mask) != state) &&
89 i < MAX_DPLL_WAIT_TRIES) {
94 if (i == MAX_DPLL_WAIT_TRIES) {
95 printk(KERN_ERR "clock: %s failed transition to '%s'\n",
96 clk->name, (state) ? "locked" : "bypassed");
98 pr_debug("clock: %s transition to '%s' in %d loops\n",
99 clk->name, (state) ? "locked" : "bypassed", i);
107 /* Non-CORE DPLL (e.g., DPLLs that do not control SDRC) clock functions */
110 * _omap3_noncore_dpll_lock - instruct a DPLL to lock and wait for readiness
111 * @clk: pointer to a DPLL struct clk
113 * Instructs a non-CORE DPLL to lock. Waits for the DPLL to report
114 * readiness before returning. Will save and restore the DPLL's
115 * autoidle state across the enable, per the CDP code. If the DPLL
116 * locked successfully, return 0; if the DPLL did not lock in the time
117 * allotted, or DPLL3 was passed in, return -EINVAL.
119 static int _omap3_noncore_dpll_lock(struct clk *clk)
124 if (clk == &dpll3_ck)
127 pr_debug("clock: locking DPLL %s\n", clk->name);
129 ai = omap3_dpll_autoidle_read(clk);
131 _omap3_dpll_write_clken(clk, DPLL_LOCKED);
135 * If no downstream clocks are enabled, CM_IDLEST bit
136 * may never become active, so don't wait for DPLL to lock.
139 omap3_dpll_allow_idle(clk);
141 r = _omap3_wait_dpll_status(clk, 1);
142 omap3_dpll_deny_idle(clk);
149 * omap3_noncore_dpll_bypass - instruct a DPLL to bypass and wait for readiness
150 * @clk: pointer to a DPLL struct clk
152 * Instructs a non-CORE DPLL to enter low-power bypass mode. In
153 * bypass mode, the DPLL's rate is set equal to its parent clock's
154 * rate. Waits for the DPLL to report readiness before returning.
155 * Will save and restore the DPLL's autoidle state across the enable,
156 * per the CDP code. If the DPLL entered bypass mode successfully,
157 * return 0; if the DPLL did not enter bypass in the time allotted, or
158 * DPLL3 was passed in, or the DPLL does not support low-power bypass,
161 static int _omap3_noncore_dpll_bypass(struct clk *clk)
166 if (clk == &dpll3_ck)
169 if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_BYPASS)))
172 pr_debug("clock: configuring DPLL %s for low-power bypass\n",
175 ai = omap3_dpll_autoidle_read(clk);
177 _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_BYPASS);
179 r = _omap3_wait_dpll_status(clk, 0);
182 omap3_dpll_allow_idle(clk);
184 omap3_dpll_deny_idle(clk);
190 * _omap3_noncore_dpll_stop - instruct a DPLL to stop
191 * @clk: pointer to a DPLL struct clk
193 * Instructs a non-CORE DPLL to enter low-power stop. Will save and
194 * restore the DPLL's autoidle state across the stop, per the CDP
195 * code. If DPLL3 was passed in, or the DPLL does not support
196 * low-power stop, return -EINVAL; otherwise, return 0.
198 static int _omap3_noncore_dpll_stop(struct clk *clk)
202 if (clk == &dpll3_ck)
205 if (!(clk->dpll_data->modes & (1 << DPLL_LOW_POWER_STOP)))
208 pr_debug("clock: stopping DPLL %s\n", clk->name);
210 ai = omap3_dpll_autoidle_read(clk);
212 _omap3_dpll_write_clken(clk, DPLL_LOW_POWER_STOP);
215 omap3_dpll_allow_idle(clk);
217 omap3_dpll_deny_idle(clk);
223 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
224 * @clk: pointer to a DPLL struct clk
226 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
227 * The choice of modes depends on the DPLL's programmed rate: if it is
228 * the same as the DPLL's parent clock, it will enter bypass;
229 * otherwise, it will enter lock. This code will wait for the DPLL to
230 * indicate readiness before returning, unless the DPLL takes too long
231 * to enter the target state. Intended to be used as the struct clk's
232 * enable function. If DPLL3 was passed in, or the DPLL does not
233 * support low-power stop, or if the DPLL took too long to enter
234 * bypass or lock, return -EINVAL; otherwise, return 0.
236 static int omap3_noncore_dpll_enable(struct clk *clk)
240 if (clk == &dpll3_ck)
243 if (clk->parent->rate == clk_get_rate(clk))
244 r = _omap3_noncore_dpll_bypass(clk);
246 r = _omap3_noncore_dpll_lock(clk);
252 * omap3_noncore_dpll_enable - instruct a DPLL to enter bypass or lock mode
253 * @clk: pointer to a DPLL struct clk
255 * Instructs a non-CORE DPLL to enable, e.g., to enter bypass or lock.
256 * The choice of modes depends on the DPLL's programmed rate: if it is
257 * the same as the DPLL's parent clock, it will enter bypass;
258 * otherwise, it will enter lock. This code will wait for the DPLL to
259 * indicate readiness before returning, unless the DPLL takes too long
260 * to enter the target state. Intended to be used as the struct clk's
261 * enable function. If DPLL3 was passed in, or the DPLL does not
262 * support low-power stop, or if the DPLL took too long to enter
263 * bypass or lock, return -EINVAL; otherwise, return 0.
265 static void omap3_noncore_dpll_disable(struct clk *clk)
267 if (clk == &dpll3_ck)
270 _omap3_noncore_dpll_stop(clk);
274 * omap3_dpll_autoidle_read - read a DPLL's autoidle bits
275 * @clk: struct clk * of the DPLL to read
277 * Return the DPLL's autoidle bits, shifted down to bit 0. Returns
278 * -EINVAL if passed a null pointer or if the struct clk does not
279 * appear to refer to a DPLL.
281 static u32 omap3_dpll_autoidle_read(struct clk *clk)
283 const struct dpll_data *dd;
286 if (!clk || !clk->dpll_data)
291 v = __raw_readl(dd->autoidle_reg);
292 v &= dd->autoidle_mask;
293 v >>= __ffs(dd->autoidle_mask);
299 * omap3_dpll_allow_idle - enable DPLL autoidle bits
300 * @clk: struct clk * of the DPLL to operate on
302 * Enable DPLL automatic idle control. This automatic idle mode
303 * switching takes effect only when the DPLL is locked, at least on
304 * OMAP3430. The DPLL will enter low-power stop when its downstream
305 * clocks are gated. No return value.
307 static void omap3_dpll_allow_idle(struct clk *clk)
309 const struct dpll_data *dd;
312 if (!clk || !clk->dpll_data)
318 * REVISIT: CORE DPLL can optionally enter low-power bypass
319 * by writing 0x5 instead of 0x1. Add some mechanism to
320 * optionally enter this mode.
322 v = __raw_readl(dd->autoidle_reg);
323 v &= ~dd->autoidle_mask;
324 v |= DPLL_AUTOIDLE_LOW_POWER_STOP << __ffs(dd->autoidle_mask);
325 __raw_writel(v, dd->autoidle_reg);
329 * omap3_dpll_deny_idle - prevent DPLL from automatically idling
330 * @clk: struct clk * of the DPLL to operate on
332 * Disable DPLL automatic idle control. No return value.
334 static void omap3_dpll_deny_idle(struct clk *clk)
336 const struct dpll_data *dd;
339 if (!clk || !clk->dpll_data)
344 v = __raw_readl(dd->autoidle_reg);
345 v &= ~dd->autoidle_mask;
346 v |= DPLL_AUTOIDLE_DISABLE << __ffs(dd->autoidle_mask);
347 __raw_writel(v, dd->autoidle_reg);
350 /* Clock control for DPLL outputs */
353 * omap3_clkoutx2_recalc - recalculate DPLL X2 output virtual clock rate
354 * @clk: DPLL output struct clk
356 * Using parent clock DPLL data, look up DPLL state. If locked, set our
357 * rate to the dpll_clk * 2; otherwise, just use dpll_clk.
359 static void omap3_clkoutx2_recalc(struct clk *clk)
361 const struct dpll_data *dd;
365 /* Walk up the parents of clk, looking for a DPLL */
367 while (pclk && !pclk->dpll_data)
370 /* clk does not have a DPLL as a parent? */
373 dd = pclk->dpll_data;
375 WARN_ON(!dd->control_reg || !dd->enable_mask);
377 v = __raw_readl(dd->control_reg) & dd->enable_mask;
378 v >>= __ffs(dd->enable_mask);
379 if (v != DPLL_LOCKED)
380 clk->rate = clk->parent->rate;
382 clk->rate = clk->parent->rate * 2;
384 if (clk->flags & RATE_PROPAGATES)
388 /* Common clock code */
391 * As it is structured now, this will prevent an OMAP2/3 multiboot
392 * kernel from compiling. This will need further attention.
394 #if defined(CONFIG_ARCH_OMAP3)
396 static struct clk_functions omap2_clk_functions = {
397 .clk_enable = omap2_clk_enable,
398 .clk_disable = omap2_clk_disable,
399 .clk_round_rate = omap2_clk_round_rate,
400 .clk_set_rate = omap2_clk_set_rate,
401 .clk_set_parent = omap2_clk_set_parent,
402 .clk_disable_unused = omap2_clk_disable_unused,
406 * Set clocks for bypass mode for reboot to work.
408 void omap2_clk_prepare_for_reboot(void)
410 /* REVISIT: Not ready for 343x */
414 if (vclk == NULL || sclk == NULL)
417 rate = clk_get_rate(sclk);
418 clk_set_rate(vclk, rate);
422 /* REVISIT: Move this init stuff out into clock.c */
425 * Switch the MPU rate if specified on cmdline.
426 * We cannot do this early until cmdline is parsed.
428 static int __init omap2_clk_arch_init(void)
433 /* REVISIT: not yet ready for 343x */
435 if (omap2_select_table_rate(&virt_prcm_set, mpurate))
436 printk(KERN_ERR "Could not find matching MPU rate\n");
439 recalculate_root_clocks();
441 printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL3/MPU): "
442 "%ld.%01ld/%ld/%ld MHz\n",
443 (osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
444 (core_ck.rate / 1000000), (dpll1_fck.rate / 1000000)) ;
448 arch_initcall(omap2_clk_arch_init);
450 int __init omap2_clk_init(void)
452 /* struct prcm_config *prcm; */
457 /* REVISIT: Ultimately this will be used for multiboot */
459 if (cpu_is_omap242x()) {
460 cpu_mask = RATE_IN_242X;
461 cpu_clkflg = CLOCK_IN_OMAP242X;
462 clkp = onchip_24xx_clks;
463 } else if (cpu_is_omap2430()) {
464 cpu_mask = RATE_IN_243X;
465 cpu_clkflg = CLOCK_IN_OMAP243X;
466 clkp = onchip_24xx_clks;
469 if (cpu_is_omap34xx()) {
470 cpu_mask = RATE_IN_343X;
471 cpu_clkflg = CLOCK_IN_OMAP343X;
472 clkp = onchip_34xx_clks;
475 * Update this if there are further clock changes between ES2
476 * and production parts
478 if (omap_rev() == OMAP3430_REV_ES1_0) {
479 /* No 3430ES1-only rates exist, so no RATE_IN_3430ES1 */
480 cpu_clkflg |= CLOCK_IN_OMAP3430ES1;
482 cpu_mask |= RATE_IN_3430ES2;
483 cpu_clkflg |= CLOCK_IN_OMAP3430ES2;
487 clk_init(&omap2_clk_functions);
489 for (clkp = onchip_34xx_clks;
490 clkp < onchip_34xx_clks + ARRAY_SIZE(onchip_34xx_clks);
492 if ((*clkp)->flags & cpu_clkflg) {
494 omap2_init_clk_clkdm(*clkp);
498 /* REVISIT: Not yet ready for OMAP3 */
500 /* Check the MPU rate set by bootloader */
501 clkrate = omap2_get_dpll_rate_24xx(&dpll_ck);
502 for (prcm = rate_table; prcm->mpu_speed; prcm++) {
503 if (!(prcm->flags & cpu_mask))
505 if (prcm->xtal_speed != sys_ck.rate)
507 if (prcm->dpll_speed <= clkrate)
510 curr_prcm_set = prcm;
513 recalculate_root_clocks();
515 printk(KERN_INFO "Clocking rate (Crystal/DPLL/ARM core): "
516 "%ld.%01ld/%ld/%ld MHz\n",
517 (osc_sys_ck.rate / 1000000), (osc_sys_ck.rate / 100000) % 10,
518 (core_ck.rate / 1000000), (arm_fck.rate / 1000000));
521 * Only enable those clocks we will need, let the drivers
522 * enable other clocks as necessary
524 clk_enable_init_clocks();
526 /* Avoid sleeping during omap2_clk_prepare_for_reboot() */
527 /* REVISIT: not yet ready for 343x */
529 vclk = clk_get(NULL, "virt_prcm_set");
530 sclk = clk_get(NULL, "sys_ck");