2 * linux/arch/arm/mach-omap2/clock.c
4 * Copyright (C) 2005-2008 Texas Instruments, Inc.
5 * Copyright (C) 2004-2008 Nokia Corporation
8 * Richard Woodruff <r-woodruff2@ti.com>
11 * Based on earlier work by Tuukka Tikkanen, Tony Lindgren,
12 * Gordon McNutt and RidgeRun, Inc.
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License version 2 as
16 * published by the Free Software Foundation.
20 #include <linux/module.h>
21 #include <linux/kernel.h>
22 #include <linux/device.h>
23 #include <linux/list.h>
24 #include <linux/errno.h>
25 #include <linux/delay.h>
26 #include <linux/clk.h>
28 #include <linux/cpufreq.h>
29 #include <linux/bitops.h>
31 #include <mach/clock.h>
32 #include <mach/sram.h>
33 #include <asm/div64.h>
38 #include "prm-regbits-24xx.h"
40 #include "cm-regbits-24xx.h"
42 static const struct clkops clkops_oscck;
43 static const struct clkops clkops_fixed;
45 #include "clock24xx.h"
47 /* CM_CLKEN_PLL.EN_{54,96}M_PLL options (24XX) */
48 #define EN_APLL_STOPPED 0
49 #define EN_APLL_LOCKED 3
51 /* CM_CLKSEL1_PLL.APLLS_CLKIN options (24XX) */
52 #define APLLS_CLKIN_19_2MHZ 0
53 #define APLLS_CLKIN_13MHZ 2
54 #define APLLS_CLKIN_12MHZ 3
56 /* #define DOWN_VARIABLE_DPLL 1 */ /* Experimental */
58 static struct prcm_config *curr_prcm_set;
59 static struct clk *vclk;
60 static struct clk *sclk;
62 /*-------------------------------------------------------------------------
63 * Omap24xx specific clock functions
64 *-------------------------------------------------------------------------*/
66 /* This actually returns the rate of core_ck, not dpll_ck. */
67 static u32 omap2_get_dpll_rate_24xx(struct clk *tclk)
72 dpll_clk = omap2_get_dpll_rate(tclk);
74 amult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
75 amult &= OMAP24XX_CORE_CLK_SRC_MASK;
81 static int omap2_enable_osc_ck(struct clk *clk)
85 pcc = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);
87 __raw_writel(pcc & ~OMAP_AUTOEXTCLKMODE_MASK,
88 OMAP24XX_PRCM_CLKSRC_CTRL);
93 static void omap2_disable_osc_ck(struct clk *clk)
97 pcc = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);
99 __raw_writel(pcc | OMAP_AUTOEXTCLKMODE_MASK,
100 OMAP24XX_PRCM_CLKSRC_CTRL);
103 static const struct clkops clkops_oscck = {
104 .enable = &omap2_enable_osc_ck,
105 .disable = &omap2_disable_osc_ck,
109 /* Recalculate SYST_CLK */
110 static void omap2_sys_clk_recalc(struct clk * clk)
112 u32 div = PRCM_CLKSRC_CTRL;
113 div &= (1 << 7) | (1 << 6); /* Test if ext clk divided by 1 or 2 */
114 div >>= clk->rate_offset;
115 clk->rate = (clk->parent->rate / div);
120 /* Enable an APLL if off */
121 static int omap2_clk_fixed_enable(struct clk *clk)
125 apll_mask = EN_APLL_LOCKED << clk->enable_bit;
127 cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
129 if ((cval & apll_mask) == apll_mask)
130 return 0; /* apll already enabled */
134 cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
136 if (clk == &apll96_ck)
137 cval = OMAP24XX_ST_96M_APLL;
138 else if (clk == &apll54_ck)
139 cval = OMAP24XX_ST_54M_APLL;
141 omap2_wait_clock_ready(OMAP_CM_REGADDR(PLL_MOD, CM_IDLEST), cval,
145 * REVISIT: Should we return an error code if omap2_wait_clock_ready()
152 static void omap2_clk_fixed_disable(struct clk *clk)
156 cval = cm_read_mod_reg(PLL_MOD, CM_CLKEN);
157 cval &= ~(EN_APLL_LOCKED << clk->enable_bit);
158 cm_write_mod_reg(cval, PLL_MOD, CM_CLKEN);
161 static const struct clkops clkops_fixed = {
162 .enable = &omap2_clk_fixed_enable,
163 .disable = &omap2_clk_fixed_disable,
167 * Uses the current prcm set to tell if a rate is valid.
168 * You can go slower, but not faster within a given rate set.
170 long omap2_dpllcore_round_rate(unsigned long target_rate)
172 u32 high, low, core_clk_src;
174 core_clk_src = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
175 core_clk_src &= OMAP24XX_CORE_CLK_SRC_MASK;
177 if (core_clk_src == CORE_CLK_SRC_DPLL) { /* DPLL clockout */
178 high = curr_prcm_set->dpll_speed * 2;
179 low = curr_prcm_set->dpll_speed;
180 } else { /* DPLL clockout x 2 */
181 high = curr_prcm_set->dpll_speed;
182 low = curr_prcm_set->dpll_speed / 2;
185 #ifdef DOWN_VARIABLE_DPLL
186 if (target_rate > high)
191 if (target_rate > low)
199 static void omap2_dpllcore_recalc(struct clk *clk)
201 clk->rate = omap2_get_dpll_rate_24xx(clk);
206 static int omap2_reprogram_dpllcore(struct clk *clk, unsigned long rate)
208 u32 cur_rate, low, mult, div, valid_rate, done_rate;
210 struct prcm_config tmpset;
211 const struct dpll_data *dd;
215 local_irq_save(flags);
216 cur_rate = omap2_get_dpll_rate_24xx(&dpll_ck);
217 mult = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
218 mult &= OMAP24XX_CORE_CLK_SRC_MASK;
220 if ((rate == (cur_rate / 2)) && (mult == 2)) {
221 omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL, 1);
222 } else if ((rate == (cur_rate * 2)) && (mult == 1)) {
223 omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);
224 } else if (rate != cur_rate) {
225 valid_rate = omap2_dpllcore_round_rate(rate);
226 if (valid_rate != rate)
230 low = curr_prcm_set->dpll_speed;
232 low = curr_prcm_set->dpll_speed / 2;
238 tmpset.cm_clksel1_pll = __raw_readl(dd->mult_div1_reg);
239 tmpset.cm_clksel1_pll &= ~(dd->mult_mask |
241 div = ((curr_prcm_set->xtal_speed / 1000000) - 1);
242 tmpset.cm_clksel2_pll = cm_read_mod_reg(PLL_MOD, CM_CLKSEL2);
243 tmpset.cm_clksel2_pll &= ~OMAP24XX_CORE_CLK_SRC_MASK;
245 tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL_X2;
246 mult = ((rate / 2) / 1000000);
247 done_rate = CORE_CLK_SRC_DPLL_X2;
249 tmpset.cm_clksel2_pll |= CORE_CLK_SRC_DPLL;
250 mult = (rate / 1000000);
251 done_rate = CORE_CLK_SRC_DPLL;
253 tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
254 tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));
257 tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;
259 if (rate == curr_prcm_set->xtal_speed) /* If asking for 1-1 */
262 omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1); /* For init_mem */
264 /* Force dll lock mode */
265 omap2_set_prcm(tmpset.cm_clksel1_pll, tmpset.base_sdrc_rfr,
268 /* Errata: ret dll entry state */
269 omap2_init_memory_params(omap2_dll_force_needed());
270 omap2_reprogram_sdrc(done_rate, 0);
272 omap2_dpllcore_recalc(&dpll_ck);
276 local_irq_restore(flags);
281 * omap2_table_mpu_recalc - just return the MPU speed
282 * @clk: virt_prcm_set struct clk
284 * Set virt_prcm_set's rate to the mpu_speed field of the current PRCM set.
286 static void omap2_table_mpu_recalc(struct clk *clk)
288 clk->rate = curr_prcm_set->mpu_speed;
292 * Look for a rate equal or less than the target rate given a configuration set.
294 * What's not entirely clear is "which" field represents the key field.
295 * Some might argue L3-DDR, others ARM, others IVA. This code is simple and
296 * just uses the ARM rates.
298 static long omap2_round_to_table_rate(struct clk *clk, unsigned long rate)
300 struct prcm_config *ptr;
303 if (clk != &virt_prcm_set)
306 highest_rate = -EINVAL;
308 for (ptr = rate_table; ptr->mpu_speed; ptr++) {
309 if (!(ptr->flags & cpu_mask))
311 if (ptr->xtal_speed != sys_ck.rate)
314 highest_rate = ptr->mpu_speed;
316 /* Can check only after xtal frequency check */
317 if (ptr->mpu_speed <= rate)
323 /* Sets basic clocks based on the specified rate */
324 static int omap2_select_table_rate(struct clk *clk, unsigned long rate)
326 u32 cur_rate, done_rate, bypass = 0, tmp;
327 struct prcm_config *prcm;
328 unsigned long found_speed = 0;
331 if (clk != &virt_prcm_set)
334 for (prcm = rate_table; prcm->mpu_speed; prcm++) {
335 if (!(prcm->flags & cpu_mask))
338 if (prcm->xtal_speed != sys_ck.rate)
341 if (prcm->mpu_speed <= rate) {
342 found_speed = prcm->mpu_speed;
348 printk(KERN_INFO "Could not set MPU rate to %luMHz\n",
353 curr_prcm_set = prcm;
354 cur_rate = omap2_get_dpll_rate_24xx(&dpll_ck);
356 if (prcm->dpll_speed == cur_rate / 2) {
357 omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL, 1);
358 } else if (prcm->dpll_speed == cur_rate * 2) {
359 omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);
360 } else if (prcm->dpll_speed != cur_rate) {
361 local_irq_save(flags);
363 if (prcm->dpll_speed == prcm->xtal_speed)
366 if ((prcm->cm_clksel2_pll & OMAP24XX_CORE_CLK_SRC_MASK) ==
367 CORE_CLK_SRC_DPLL_X2)
368 done_rate = CORE_CLK_SRC_DPLL_X2;
370 done_rate = CORE_CLK_SRC_DPLL;
373 cm_write_mod_reg(prcm->cm_clksel_mpu, MPU_MOD, CM_CLKSEL);
375 /* dsp + iva1 div(2420), iva2.1(2430) */
376 cm_write_mod_reg(prcm->cm_clksel_dsp,
377 OMAP24XX_DSP_MOD, CM_CLKSEL);
379 cm_write_mod_reg(prcm->cm_clksel_gfx, GFX_MOD, CM_CLKSEL);
381 /* Major subsystem dividers */
382 tmp = cm_read_mod_reg(CORE_MOD, CM_CLKSEL1) & OMAP24XX_CLKSEL_DSS2_MASK;
383 cm_write_mod_reg(prcm->cm_clksel1_core | tmp, CORE_MOD, CM_CLKSEL1);
384 if (cpu_is_omap2430())
385 cm_write_mod_reg(prcm->cm_clksel_mdm,
386 OMAP2430_MDM_MOD, CM_CLKSEL);
388 /* x2 to enter init_mem */
389 omap2_reprogram_sdrc(CORE_CLK_SRC_DPLL_X2, 1);
391 omap2_set_prcm(prcm->cm_clksel1_pll, prcm->base_sdrc_rfr,
394 omap2_init_memory_params(omap2_dll_force_needed());
395 omap2_reprogram_sdrc(done_rate, 0);
397 local_irq_restore(flags);
399 omap2_dpllcore_recalc(&dpll_ck);
404 static struct clk_functions omap2_clk_functions = {
405 .clk_enable = omap2_clk_enable,
406 .clk_disable = omap2_clk_disable,
407 .clk_round_rate = omap2_clk_round_rate,
408 .clk_set_rate = omap2_clk_set_rate,
409 .clk_set_parent = omap2_clk_set_parent,
410 .clk_disable_unused = omap2_clk_disable_unused,
413 static u32 omap2_get_apll_clkin(void)
417 aplls = cm_read_mod_reg(PLL_MOD, CM_CLKSEL1);
418 aplls &= OMAP24XX_APLLS_CLKIN_MASK;
419 aplls >>= OMAP24XX_APLLS_CLKIN_SHIFT;
421 if (aplls == APLLS_CLKIN_19_2MHZ)
423 else if (aplls == APLLS_CLKIN_13MHZ)
425 else if (aplls == APLLS_CLKIN_12MHZ)
431 static u32 omap2_get_sysclkdiv(void)
435 div = __raw_readl(OMAP24XX_PRCM_CLKSRC_CTRL);
436 div &= OMAP_SYSCLKDIV_MASK;
437 div >>= OMAP_SYSCLKDIV_SHIFT;
442 static void omap2_osc_clk_recalc(struct clk *clk)
444 clk->rate = omap2_get_apll_clkin() * omap2_get_sysclkdiv();
448 static void omap2_sys_clk_recalc(struct clk *clk)
450 clk->rate = clk->parent->rate / omap2_get_sysclkdiv();
455 * Set clocks for bypass mode for reboot to work.
457 void omap2_clk_prepare_for_reboot(void)
461 if (vclk == NULL || sclk == NULL)
464 rate = clk_get_rate(sclk);
465 clk_set_rate(vclk, rate);
469 * Switch the MPU rate if specified on cmdline.
470 * We cannot do this early until cmdline is parsed.
472 static int __init omap2_clk_arch_init(void)
477 if (omap2_select_table_rate(&virt_prcm_set, mpurate))
478 printk(KERN_ERR "Could not find matching MPU rate\n");
480 recalculate_root_clocks();
482 printk(KERN_INFO "Switched to new clocking rate (Crystal/DPLL/MPU): "
483 "%ld.%01ld/%ld/%ld MHz\n",
484 (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
485 (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
489 arch_initcall(omap2_clk_arch_init);
491 int __init omap2_clk_init(void)
493 struct prcm_config *prcm;
497 if (cpu_is_omap242x())
498 cpu_mask = RATE_IN_242X;
499 else if (cpu_is_omap2430())
500 cpu_mask = RATE_IN_243X;
502 clk_init(&omap2_clk_functions);
504 omap2_osc_clk_recalc(&osc_ck);
505 omap2_sys_clk_recalc(&sys_ck);
507 for (clkp = onchip_24xx_clks;
508 clkp < onchip_24xx_clks + ARRAY_SIZE(onchip_24xx_clks);
511 if ((*clkp)->flags & CLOCK_IN_OMAP242X && cpu_is_omap2420()) {
516 if ((*clkp)->flags & CLOCK_IN_OMAP243X && cpu_is_omap2430()) {
522 /* Check the MPU rate set by bootloader */
523 clkrate = omap2_get_dpll_rate_24xx(&dpll_ck);
524 for (prcm = rate_table; prcm->mpu_speed; prcm++) {
525 if (!(prcm->flags & cpu_mask))
527 if (prcm->xtal_speed != sys_ck.rate)
529 if (prcm->dpll_speed <= clkrate)
532 curr_prcm_set = prcm;
534 recalculate_root_clocks();
536 printk(KERN_INFO "Clocking rate (Crystal/DPLL/MPU): "
537 "%ld.%01ld/%ld/%ld MHz\n",
538 (sys_ck.rate / 1000000), (sys_ck.rate / 100000) % 10,
539 (dpll_ck.rate / 1000000), (mpu_ck.rate / 1000000)) ;
542 * Only enable those clocks we will need, let the drivers
543 * enable other clocks as necessary
545 clk_enable_init_clocks();
547 /* Avoid sleeping sleeping during omap2_clk_prepare_for_reboot() */
548 vclk = clk_get(NULL, "virt_prcm_set");
549 sclk = clk_get(NULL, "sys_ck");