clock.c 9.3 KB
Newer Older
1 2 3
/*
 *  linux/arch/arm/mach-omap2/clock.c
 *
4 5
 *  Copyright (C) 2005-2008 Texas Instruments, Inc.
 *  Copyright (C) 2004-2008 Nokia Corporation
6
 *
7 8
 *  Contacts:
 *  Richard Woodruff <r-woodruff2@ti.com>
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
 *  Paul Walmsley
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#undef DEBUG

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/clk.h>
24
#include <linux/io.h>
25
#include <linux/bitops.h>
26

27 28 29 30
#include <plat/clock.h>
#include <plat/clockdomain.h>
#include <plat/cpu.h>
#include <plat/prcm.h>
31 32 33 34 35 36 37 38 39 40 41

#include "clock.h"
#include "prm.h"
#include "prm-regbits-24xx.h"
#include "cm.h"
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"

u8 cpu_mask;

/*-------------------------------------------------------------------------
42
 * OMAP2/3/4 specific clock functions
43 44
 *-------------------------------------------------------------------------*/

45
/**
46
 * omap2xxx_clk_commit - commit clock parent/rate changes in hardware
47 48 49 50 51 52
 * @clk: struct clk *
 *
 * If @clk has the DELAYED_APP flag set, meaning that parent/rate changes
 * don't take effect until the VALID_CONFIG bit is written, write the
 * VALID_CONFIG bit and wait for the write to complete.  No return value.
 */
53
void omap2xxx_clk_commit(struct clk *clk)
54 55 56 57 58 59 60 61
{
	if (!cpu_is_omap24xx())
		return;

	if (!(clk->flags & DELAYED_APP))
		return;

	prm_write_mod_reg(OMAP24XX_VALID_CONFIG, OMAP24XX_GR_MOD,
62
		OMAP2_PRCM_CLKCFG_CTRL_OFFSET);
63
	/* OCP barrier */
64
	prm_read_mod_reg(OMAP24XX_GR_MOD, OMAP2_PRCM_CLKCFG_CTRL_OFFSET);
65 66
}

67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92
/**
 * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
 * @clk: OMAP clock struct ptr to use
 *
 * Convert a clockdomain name stored in a struct clk 'clk' into a
 * clockdomain pointer, and save it into the struct clk.  Intended to be
 * called during clk_register().  No return value.
 */
void omap2_init_clk_clkdm(struct clk *clk)
{
	struct clockdomain *clkdm;

	if (!clk->clkdm_name)
		return;

	clkdm = clkdm_lookup(clk->clkdm_name);
	if (clkdm) {
		pr_debug("clock: associated clk %s to clkdm %s\n",
			 clk->name, clk->clkdm_name);
		clk->clkdm = clkdm;
	} else {
		pr_debug("clock: could not associate clk %s to "
			 "clkdm %s\n", clk->name, clk->clkdm_name);
	}
}

93
/**
94 95 96 97 98 99 100 101
 * omap2_clk_dflt_find_companion - find companion clock to @clk
 * @clk: struct clk * to find the companion clock of
 * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in
 * @other_bit: u8 ** to return the companion clock bit shift in
 *
 * Note: We don't need special code here for INVERT_ENABLE for the
 * time being since INVERT_ENABLE only applies to clocks enabled by
 * CM_CLKEN_PLL
102
 *
103 104 105 106 107 108 109 110 111 112
 * Convert CM_ICLKEN* <-> CM_FCLKEN*.  This conversion assumes it's
 * just a matter of XORing the bits.
 *
 * Some clocks don't have companion clocks.  For example, modules with
 * only an interface clock (such as MAILBOXES) don't have a companion
 * clock.  Right now, this code relies on the hardware exporting a bit
 * in the correct companion register that indicates that the
 * nonexistent 'companion clock' is active.  Future patches will
 * associate this type of code with per-module data structures to
 * avoid this issue, and remove the casts.  No return value.
113
 */
114 115
void omap2_clk_dflt_find_companion(struct clk *clk, void __iomem **other_reg,
				   u8 *other_bit)
116
{
117
	u32 r;
118 119

	/*
120 121
	 * Convert CM_ICLKEN* <-> CM_FCLKEN*.  This conversion assumes
	 * it's just a matter of XORing the bits.
122
	 */
123
	r = ((__force u32)clk->enable_reg ^ (CM_FCLKEN ^ CM_ICLKEN));
124

125 126 127
	*other_reg = (__force void __iomem *)r;
	*other_bit = clk->enable_bit;
}
128

129 130 131 132 133 134 135 136 137 138 139 140
/**
 * omap2_clk_dflt_find_idlest - find CM_IDLEST reg va, bit shift for @clk
 * @clk: struct clk * to find IDLEST info for
 * @idlest_reg: void __iomem ** to return the CM_IDLEST va in
 * @idlest_bit: u8 ** to return the CM_IDLEST bit shift in
 *
 * Return the CM_IDLEST register address and bit shift corresponding
 * to the module that "owns" this clock.  This default code assumes
 * that the CM_IDLEST bit shift is the CM_*CLKEN bit shift, and that
 * the IDLEST register address ID corresponds to the CM_*CLKEN
 * register address ID (e.g., that CM_FCLKEN2 corresponds to
 * CM_IDLEST2).  This is not true for all modules.  No return value.
141
 */
142 143
void omap2_clk_dflt_find_idlest(struct clk *clk, void __iomem **idlest_reg,
				u8 *idlest_bit)
144
{
145
	u32 r;
146

147 148 149 150
	r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20);
	*idlest_reg = (__force void __iomem *)r;
	*idlest_bit = clk->enable_bit;
}
151

152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172
/**
 * omap2_module_wait_ready - wait for an OMAP module to leave IDLE
 * @clk: struct clk * belonging to the module
 *
 * If the necessary clocks for the OMAP hardware IP block that
 * corresponds to clock @clk are enabled, then wait for the module to
 * indicate readiness (i.e., to leave IDLE).  This code does not
 * belong in the clock code and will be moved in the medium term to
 * module-dependent code.  No return value.
 */
static void omap2_module_wait_ready(struct clk *clk)
{
	void __iomem *companion_reg, *idlest_reg;
	u8 other_bit, idlest_bit;

	/* Not all modules have multiple clocks that their IDLEST depends on */
	if (clk->ops->find_companion) {
		clk->ops->find_companion(clk, &companion_reg, &other_bit);
		if (!(__raw_readl(companion_reg) & (1 << other_bit)))
			return;
	}
173

174
	clk->ops->find_idlest(clk, &idlest_reg, &idlest_bit);
175

176
	omap2_cm_wait_idlest(idlest_reg, (1 << idlest_bit), clk->name);
177 178
}

179
int omap2_dflt_clk_enable(struct clk *clk)
180
{
181
	u32 v;
182

183
	if (unlikely(clk->enable_reg == NULL)) {
184
		pr_err("clock.c: Enable for %s without enable code\n",
185 186 187 188
		       clk->name);
		return 0; /* REVISIT: -EINVAL */
	}

189
	v = __raw_readl(clk->enable_reg);
190
	if (clk->flags & INVERT_ENABLE)
191
		v &= ~(1 << clk->enable_bit);
192
	else
193 194
		v |= (1 << clk->enable_bit);
	__raw_writel(v, clk->enable_reg);
195
	v = __raw_readl(clk->enable_reg); /* OCP barrier */
196

197 198
	if (clk->ops->find_idlest)
		omap2_module_wait_ready(clk);
199

200
	return 0;
201 202
}

203
void omap2_dflt_clk_disable(struct clk *clk)
204
{
205
	u32 v;
206

207
	if (!clk->enable_reg) {
208 209 210 211 212 213 214 215 216
		/*
		 * 'Independent' here refers to a clock which is not
		 * controlled by its parent.
		 */
		printk(KERN_ERR "clock: clk_disable called on independent "
		       "clock %s which has no enable_reg\n", clk->name);
		return;
	}

217
	v = __raw_readl(clk->enable_reg);
218
	if (clk->flags & INVERT_ENABLE)
219
		v |= (1 << clk->enable_bit);
220
	else
221 222
		v &= ~(1 << clk->enable_bit);
	__raw_writel(v, clk->enable_reg);
223
	/* No OCP barrier needed here since it is a disable operation */
224 225
}

226
const struct clkops clkops_omap2_dflt_wait = {
227
	.enable		= omap2_dflt_clk_enable,
228
	.disable	= omap2_dflt_clk_disable,
229 230
	.find_companion	= omap2_clk_dflt_find_companion,
	.find_idlest	= omap2_clk_dflt_find_idlest,
231 232
};

233 234 235 236 237
const struct clkops clkops_omap2_dflt = {
	.enable		= omap2_dflt_clk_enable,
	.disable	= omap2_dflt_clk_disable,
};

238 239 240 241 242 243 244 245 246 247 248 249
/* Enables clock without considering parent dependencies or use count
 * REVISIT: Maybe change this to use clk->enable like on omap1?
 */
static int _omap2_clk_enable(struct clk *clk)
{
	return clk->ops->enable(clk);
}

/* Disables clock without considering parent dependencies or use count */
static void _omap2_clk_disable(struct clk *clk)
{
	clk->ops->disable(clk);
250 251 252 253 254 255
}

void omap2_clk_disable(struct clk *clk)
{
	if (clk->usecount > 0 && !(--clk->usecount)) {
		_omap2_clk_disable(clk);
256
		if (clk->parent)
257
			omap2_clk_disable(clk->parent);
258 259 260
		if (clk->clkdm)
			omap2_clkdm_clk_disable(clk->clkdm, clk);

261 262 263 264 265 266 267 268
	}
}

int omap2_clk_enable(struct clk *clk)
{
	int ret = 0;

	if (clk->usecount++ == 0) {
269 270 271
		if (clk->clkdm)
			omap2_clkdm_clk_enable(clk->clkdm, clk);

272
		if (clk->parent) {
273
			ret = omap2_clk_enable(clk->parent);
274 275
			if (ret)
				goto err;
276
		}
277

278
		ret = _omap2_clk_enable(clk);
279 280
		if (ret) {
			if (clk->parent)
281
				omap2_clk_disable(clk->parent);
282 283

			goto err;
284 285
		}
	}
286
	return ret;
287

288
err:
289 290
	if (clk->clkdm)
		omap2_clkdm_clk_disable(clk->clkdm, clk);
291
	clk->usecount--;
292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307
	return ret;
}

/* Set the clock rate for a clock source */
int omap2_clk_set_rate(struct clk *clk, unsigned long rate)
{
	int ret = -EINVAL;

	pr_debug("clock: set_rate for clock %s to rate %ld\n", clk->name, rate);

	/* CONFIG_PARTICIPANT clocks are changed only in sets via the
	   rate table mechanism, driven by mpu_speed  */
	if (clk->flags & CONFIG_PARTICIPANT)
		return -EINVAL;

	/* dpll_ck, core_ck, virt_prcm_set; plus all clksel clocks */
308
	if (clk->set_rate)
309 310 311 312 313 314 315
		ret = clk->set_rate(clk, rate);

	return ret;
}

int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent)
{
316
	if (clk->flags & CONFIG_PARTICIPANT)
317 318 319 320 321
		return -EINVAL;

	if (!clk->clksel)
		return -EINVAL;

322
	return omap2_clksel_set_parent(clk, new_parent);
323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339
}

/*-------------------------------------------------------------------------
 * Omap2 clock reset and init functions
 *-------------------------------------------------------------------------*/

#ifdef CONFIG_OMAP_RESET_CLOCKS
void omap2_clk_disable_unused(struct clk *clk)
{
	u32 regval32, v;

	v = (clk->flags & INVERT_ENABLE) ? (1 << clk->enable_bit) : 0;

	regval32 = __raw_readl(clk->enable_reg);
	if ((regval32 & (1 << clk->enable_bit)) == v)
		return;

340
	printk(KERN_DEBUG "Disabling unused clock \"%s\"\n", clk->name);
341 342 343 344 345
	if (cpu_is_omap34xx()) {
		omap2_clk_enable(clk);
		omap2_clk_disable(clk);
	} else
		_omap2_clk_disable(clk);
346 347
	if (clk->clkdm != NULL)
		pwrdm_clkdm_state_switch(clk->clkdm);
348 349
}
#endif