- 根目录:
- arch
- arm
- mach-s3c2443
- clock.c
/* linux/arch/arm/mach-s3c2443/clock.c
*
* Copyright (c) 2007, 2010 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2443 Clock control support
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/sysdev.h>
#include <linux/clk.h>
#include <linux/mutex.h>
#include <linux/serial_core.h>
#include <linux/io.h>
#include <asm/mach/map.h>
#include <mach/hardware.h>
#include <mach/regs-s3c2443-clock.h>
#include <plat/cpu-freq.h>
#include <plat/s3c2443.h>
#include <plat/clock.h>
#include <plat/clock-clksrc.h>
#include <plat/cpu.h>
/* We currently have to assume that the system is running
* from the XTPll input, and that all ***REFCLKs are being
* fed from it, as we cannot read the state of OM[4] from
* software.
*
* It would be possible for each board initialisation to
* set the correct muxing at initialisation
*/
/* clock selections */
static struct clk clk_i2s_ext = {
.name = "i2s-ext",
.id = -1,
};
/* armdiv
*
* this clock is sourced from msysclk and can have a number of
* divider values applied to it to then be fed into armclk.
*/
/* armdiv divisor table */
static unsigned int armdiv[16] = {
[S3C2443_CLKDIV0_ARMDIV_1 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 1,
[S3C2443_CLKDIV0_ARMDIV_2 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 2,
[S3C2443_CLKDIV0_ARMDIV_3 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 3,
[S3C2443_CLKDIV0_ARMDIV_4 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 4,
[S3C2443_CLKDIV0_ARMDIV_6 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 6,
[S3C2443_CLKDIV0_ARMDIV_8 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 8,
[S3C2443_CLKDIV0_ARMDIV_12 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 12,
[S3C2443_CLKDIV0_ARMDIV_16 >> S3C2443_CLKDIV0_ARMDIV_SHIFT] = 16,
};
static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0)
{
clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;
return armdiv[clkcon0 >> S3C2443_CLKDIV0_ARMDIV_SHIFT];
}
static unsigned long s3c2443_armclk_roundrate(struct clk *clk,
unsigned long rate)
{
unsigned long parent = clk_get_rate(clk->parent);
unsigned long calc;
unsigned best = 256; /* bigger than any value */
unsigned div;
int ptr;
for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) {
div = armdiv[ptr];
calc = parent / div;
if (calc <= rate && div < best)
best = div;
}
return parent / best;
}
static int s3c2443_armclk_setrate(struct clk *clk, unsigned long rate)
{
unsigned long parent = clk_get_rate(clk->parent);
unsigned long calc;
unsigned div;
unsigned best = 256; /* bigger than any value */
int ptr;
int val = -1;
for (ptr = 0; ptr < ARRAY_SIZE(armdiv); ptr++) {
div = armdiv[ptr];
calc = parent / div;
if (calc <= rate && div < best) {
best = div;
val = ptr;
}
}
if (val >= 0) {
unsigned long clkcon0;
clkcon0 = __raw_readl(S3C2443_CLKDIV0);
clkcon0 &= S3C2443_CLKDIV0_ARMDIV_MASK;
clkcon0 |= val << S3C2443_CLKDIV0_ARMDIV_SHIFT;
__raw_writel(clkcon0, S3C2443_CLKDIV0);
}
return (val == -1) ? -EINVAL : 0;
}
static struct clk clk_armdiv = {
.name = "armdiv",
.id = -1,
.parent = &clk_msysclk.clk,
.ops = &(struct clk_ops) {
.round_rate = s3c2443_armclk_roundrate,
.set_rate = s3c2443_armclk_setrate,
},
};
/* armclk
*
* this is the clock fed into the ARM core itself, from armdiv or from hclk.
*/
static struct clk *clk_arm_sources[] = {
[0] = &clk_armdiv,
[1] = &clk_h,
};
static struct clksrc_clk clk_arm = {
.clk = {
.name = "armclk",
.id = -1,
},
.sources = &(struct clksrc_sources) {
.sources = clk_arm_sources,
.nr_sources = ARRAY_SIZE(clk_arm_sources),
},
.reg_src = { .reg = S3C2443_CLKDIV0, .size = 1, .shift = 13 },
};
/* hsspi
*
* high-speed spi clock, sourced from esysclk
*/
static struct clksrc_clk clk_hsspi = {
.clk = {
.name = "hsspi",
.id = -1,
.parent = &clk_esysclk.clk,
.ctrlbit = S3C2443_SCLKCON_HSSPICLK,
.enable = s3c2443_clkcon_enable_s,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 4 },
};
/* clk_hsmcc_div
*
* this clock is sourced from epll, and is fed through a divider,
* to a mux controlled by sclkcon where either it or a extclk can
* be fed to the hsmmc block
*/
static struct clksrc_clk clk_hsmmc_div = {
.clk = {
.name = "hsmmc-div",
.id = 1,
.parent = &clk_esysclk.clk,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 2, .shift = 6 },
};
static int s3c2443_setparent_hsmmc(struct clk *clk, struct clk *parent)
{
unsigned long clksrc = __raw_readl(S3C2443_SCLKCON);
clksrc &= ~(S3C2443_SCLKCON_HSMMCCLK_EXT |
S3C2443_SCLKCON_HSMMCCLK_EPLL);
if (parent == &clk_epll)
clksrc |= S3C2443_SCLKCON_HSMMCCLK_EPLL;
else if (parent == &clk_ext)
clksrc |= S3C2443_SCLKCON_HSMMCCLK_EXT;
else
return -EINVAL;
if (clk->usage > 0) {
__raw_writel(clksrc, S3C2443_SCLKCON);
}
clk->parent = parent;
return 0;
}
static int s3c2443_enable_hsmmc(struct clk *clk, int enable)
{
return s3c2443_setparent_hsmmc(clk, clk->parent);
}
static struct clk clk_hsmmc = {
.name = "hsmmc-if",
.id = 1,
.parent = &clk_hsmmc_div.clk,
.enable = s3c2443_enable_hsmmc,
.ops = &(struct clk_ops) {
.set_parent = s3c2443_setparent_hsmmc,
},
};
/* i2s_eplldiv
*
* This clock is the output from the I2S divisor of ESYSCLK, and is separate
* from the mux that comes after it (cannot merge into one single clock)
*/
static struct clksrc_clk clk_i2s_eplldiv = {
.clk = {
.name = "i2s-eplldiv",
.id = -1,
.parent = &clk_esysclk.clk,
},
.reg_div = { .reg = S3C2443_CLKDIV1, .size = 4, .shift = 12, },
};
/* i2s-ref
*
* i2s bus reference clock, selectable from external, esysclk or epllref
*
* Note, this used to be two clocks, but was compressed into one.
*/
struct clk *clk_i2s_srclist[] = {
[0] = &clk_i2s_eplldiv.clk,
[1] = &clk_i2s_ext,
[2] = &clk_epllref.clk,
[3] = &clk_epllref.clk,
};
static struct clksrc_clk clk_i2s = {
.clk = {
.name = "i2s-if",
.id = -1,
.ctrlbit = S3C2443_SCLKCON_I2SCLK,
.enable = s3c2443_clkcon_enable_s,
},
.sources = &(struct clksrc_sources) {
.sources = clk_i2s_srclist,
.nr_sources = ARRAY_SIZE(clk_i2s_srclist),
},
.reg_src = { .reg = S3C2443_CLKSRC, .size = 2, .shift = 14 },
};
/* standard clock definitions */
static struct clk init_clocks_off[] = {
{
.name = "sdi",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_SDI,
}, {
.name = "iis",
.id = -1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_IIS,
}, {
.name = "spi",
.id = 0,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_SPI0,
}, {
.name = "spi",
.id = 1,
.parent = &clk_p,
.enable = s3c2443_clkcon_enable_p,
.ctrlbit = S3C2443_PCLKCON_SPI1,
}
};
static struct clk init_clocks[] = {
};
/* clocks to add straight away */
static struct clksrc_clk *clksrcs[] __initdata = {
&clk_arm,
&clk_i2s_eplldiv,
&clk_i2s,
&clk_hsspi,
&clk_hsmmc_div,
};
static struct clk *clks[] __initdata = {
&clk_hsmmc,
&clk_armdiv,
};
void __init_or_cpufreq s3c2443_setup_clocks(void)
{
s3c2443_common_setup_clocks(s3c2443_get_mpll, s3c2443_fclk_div);
}
void __init s3c2443_init_clocks(int xtal)
{
unsigned long epllcon = __raw_readl(S3C2443_EPLLCON);
int ptr;
clk_epll.rate = s3c2443_get_epll(epllcon, xtal);
clk_epll.parent = &clk_epllref.clk;
s3c2443_common_init_clocks(xtal, s3c2443_get_mpll, s3c2443_fclk_div);
s3c2443_setup_clocks();
s3c24xx_register_clocks(clks, ARRAY_SIZE(clks));
for (ptr = 0; ptr < ARRAY_SIZE(clksrcs); ptr++)
s3c_register_clksrc(clksrcs[ptr], 1);
/* register clocks from clock array */
s3c_register_clocks(init_clocks, ARRAY_SIZE(init_clocks));
/* We must be careful disabling the clocks we are not intending to
* be using at boot time, as subsystems such as the LCD which do
* their own DMA requests to the bus can cause the system to lockup
* if they where in the middle of requesting bus access.
*
* Disabling the LCD clock if the LCD is active is very dangerous,
* and therefore the bootloader should be careful to not enable
* the LCD clock if it is not needed.
*/
/* install (and disable) the clocks we do not need immediately */
s3c_register_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));
s3c_disable_clocks(init_clocks_off, ARRAY_SIZE(init_clocks_off));
s3c_pwmclk_init();
}