1 /* linux/arch/arm/mach-s3c2443/clock.c
3 * Copyright (c) 2007, 2010 Simtec Electronics
4 * Ben Dooks <ben@simtec.co.uk>
6 * S3C2443 Clock control support
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.
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.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 #include <linux/init.h>
25 #include <linux/module.h>
26 #include <linux/kernel.h>
27 #include <linux/list.h>
28 #include <linux/errno.h>
29 #include <linux/err.h>
30 #include <linux/sysdev.h>
31 #include <linux/clk.h>
32 #include <linux/mutex.h>
33 #include <linux/serial_core.h>
36 #include <asm/mach/map.h>
38 #include <mach/hardware.h>
40 #include <mach/regs-s3c2443-clock.h>
42 #include <plat/cpu-freq.h>
44 #include <plat/s3c2443.h>
45 #include <plat/clock.h>
46 #include <plat/clock-clksrc.h>
49 /* We currently have to assume that the system is running
50 * from the XTPll input, and that all ***REFCLKs are being
51 * fed from it, as we cannot read the state of OM[4] from
54 * It would be possible for each board initialisation to
55 * set the correct muxing at initialisation
58 /* clock selections */
60 static struct clk clk_i2s_ext
= {
66 * this clock is sourced from msysclk and can have a number of
67 * divider values applied to it to then be fed into armclk.
70 /* armdiv divisor table */
72 static unsigned int armdiv
[16] = {
73 [S3C2443_CLKDIV0_ARMDIV_1
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 1,
74 [S3C2443_CLKDIV0_ARMDIV_2
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 2,
75 [S3C2443_CLKDIV0_ARMDIV_3
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 3,
76 [S3C2443_CLKDIV0_ARMDIV_4
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 4,
77 [S3C2443_CLKDIV0_ARMDIV_6
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 6,
78 [S3C2443_CLKDIV0_ARMDIV_8
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 8,
79 [S3C2443_CLKDIV0_ARMDIV_12
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 12,
80 [S3C2443_CLKDIV0_ARMDIV_16
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
] = 16,
83 static inline unsigned int s3c2443_fclk_div(unsigned long clkcon0
)
85 clkcon0
&= S3C2443_CLKDIV0_ARMDIV_MASK
;
87 return armdiv
[clkcon0
>> S3C2443_CLKDIV0_ARMDIV_SHIFT
];
90 static unsigned long s3c2443_armclk_roundrate(struct clk
*clk
,
93 unsigned long parent
= clk_get_rate(clk
->parent
);
95 unsigned best
= 256; /* bigger than any value */
99 for (ptr
= 0; ptr
< ARRAY_SIZE(armdiv
); ptr
++) {
102 if (calc
<= rate
&& div
< best
)
106 return parent
/ best
;
109 static int s3c2443_armclk_setrate(struct clk
*clk
, unsigned long rate
)
111 unsigned long parent
= clk_get_rate(clk
->parent
);
114 unsigned best
= 256; /* bigger than any value */
118 for (ptr
= 0; ptr
< ARRAY_SIZE(armdiv
); ptr
++) {
121 if (calc
<= rate
&& div
< best
) {
128 unsigned long clkcon0
;
130 clkcon0
= __raw_readl(S3C2443_CLKDIV0
);
131 clkcon0
&= S3C2443_CLKDIV0_ARMDIV_MASK
;
132 clkcon0
|= val
<< S3C2443_CLKDIV0_ARMDIV_SHIFT
;
133 __raw_writel(clkcon0
, S3C2443_CLKDIV0
);
136 return (val
== -1) ? -EINVAL
: 0;
139 static struct clk clk_armdiv
= {
141 .parent
= &clk_msysclk
.clk
,
142 .ops
= &(struct clk_ops
) {
143 .round_rate
= s3c2443_armclk_roundrate
,
144 .set_rate
= s3c2443_armclk_setrate
,
150 * this is the clock fed into the ARM core itself, from armdiv or from hclk.
153 static struct clk
*clk_arm_sources
[] = {
158 static struct clksrc_clk clk_arm
= {
162 .sources
= &(struct clksrc_sources
) {
163 .sources
= clk_arm_sources
,
164 .nr_sources
= ARRAY_SIZE(clk_arm_sources
),
166 .reg_src
= { .reg
= S3C2443_CLKDIV0
, .size
= 1, .shift
= 13 },
171 * high-speed spi clock, sourced from esysclk
174 static struct clksrc_clk clk_hsspi
= {
177 .parent
= &clk_esysclk
.clk
,
178 .ctrlbit
= S3C2443_SCLKCON_HSSPICLK
,
179 .enable
= s3c2443_clkcon_enable_s
,
181 .reg_div
= { .reg
= S3C2443_CLKDIV1
, .size
= 2, .shift
= 4 },
187 * this clock is sourced from epll, and is fed through a divider,
188 * to a mux controlled by sclkcon where either it or a extclk can
189 * be fed to the hsmmc block
192 static struct clksrc_clk clk_hsmmc_div
= {
195 .devname
= "s3c-sdhci.1",
196 .parent
= &clk_esysclk
.clk
,
198 .reg_div
= { .reg
= S3C2443_CLKDIV1
, .size
= 2, .shift
= 6 },
201 static int s3c2443_setparent_hsmmc(struct clk
*clk
, struct clk
*parent
)
203 unsigned long clksrc
= __raw_readl(S3C2443_SCLKCON
);
205 clksrc
&= ~(S3C2443_SCLKCON_HSMMCCLK_EXT
|
206 S3C2443_SCLKCON_HSMMCCLK_EPLL
);
208 if (parent
== &clk_epll
)
209 clksrc
|= S3C2443_SCLKCON_HSMMCCLK_EPLL
;
210 else if (parent
== &clk_ext
)
211 clksrc
|= S3C2443_SCLKCON_HSMMCCLK_EXT
;
215 if (clk
->usage
> 0) {
216 __raw_writel(clksrc
, S3C2443_SCLKCON
);
219 clk
->parent
= parent
;
223 static int s3c2443_enable_hsmmc(struct clk
*clk
, int enable
)
225 return s3c2443_setparent_hsmmc(clk
, clk
->parent
);
228 static struct clk clk_hsmmc
= {
230 .devname
= "s3c-sdhci.1",
231 .parent
= &clk_hsmmc_div
.clk
,
232 .enable
= s3c2443_enable_hsmmc
,
233 .ops
= &(struct clk_ops
) {
234 .set_parent
= s3c2443_setparent_hsmmc
,
240 * This clock is the output from the I2S divisor of ESYSCLK, and is separate
241 * from the mux that comes after it (cannot merge into one single clock)
244 static struct clksrc_clk clk_i2s_eplldiv
= {
246 .name
= "i2s-eplldiv",
247 .parent
= &clk_esysclk
.clk
,
249 .reg_div
= { .reg
= S3C2443_CLKDIV1
, .size
= 4, .shift
= 12, },
254 * i2s bus reference clock, selectable from external, esysclk or epllref
256 * Note, this used to be two clocks, but was compressed into one.
259 struct clk
*clk_i2s_srclist
[] = {
260 [0] = &clk_i2s_eplldiv
.clk
,
262 [2] = &clk_epllref
.clk
,
263 [3] = &clk_epllref
.clk
,
266 static struct clksrc_clk clk_i2s
= {
269 .ctrlbit
= S3C2443_SCLKCON_I2SCLK
,
270 .enable
= s3c2443_clkcon_enable_s
,
273 .sources
= &(struct clksrc_sources
) {
274 .sources
= clk_i2s_srclist
,
275 .nr_sources
= ARRAY_SIZE(clk_i2s_srclist
),
277 .reg_src
= { .reg
= S3C2443_CLKSRC
, .size
= 2, .shift
= 14 },
280 /* standard clock definitions */
282 static struct clk init_clocks_off
[] = {
286 .enable
= s3c2443_clkcon_enable_p
,
287 .ctrlbit
= S3C2443_PCLKCON_SDI
,
291 .enable
= s3c2443_clkcon_enable_p
,
292 .ctrlbit
= S3C2443_PCLKCON_IIS
,
295 .devname
= "s3c2410-spi.0",
297 .enable
= s3c2443_clkcon_enable_p
,
298 .ctrlbit
= S3C2443_PCLKCON_SPI0
,
301 .devname
= "s3c2410-spi.1",
303 .enable
= s3c2443_clkcon_enable_p
,
304 .ctrlbit
= S3C2443_PCLKCON_SPI1
,
308 static struct clk init_clocks
[] = {
311 /* clocks to add straight away */
313 static struct clksrc_clk
*clksrcs
[] __initdata
= {
321 static struct clk
*clks
[] __initdata
= {
326 void __init_or_cpufreq
s3c2443_setup_clocks(void)
328 s3c2443_common_setup_clocks(s3c2443_get_mpll
, s3c2443_fclk_div
);
331 void __init
s3c2443_init_clocks(int xtal
)
333 unsigned long epllcon
= __raw_readl(S3C2443_EPLLCON
);
336 clk_epll
.rate
= s3c2443_get_epll(epllcon
, xtal
);
337 clk_epll
.parent
= &clk_epllref
.clk
;
339 s3c2443_common_init_clocks(xtal
, s3c2443_get_mpll
, s3c2443_fclk_div
);
341 s3c2443_setup_clocks();
343 s3c24xx_register_clocks(clks
, ARRAY_SIZE(clks
));
345 for (ptr
= 0; ptr
< ARRAY_SIZE(clksrcs
); ptr
++)
346 s3c_register_clksrc(clksrcs
[ptr
], 1);
348 /* register clocks from clock array */
350 s3c_register_clocks(init_clocks
, ARRAY_SIZE(init_clocks
));
352 /* We must be careful disabling the clocks we are not intending to
353 * be using at boot time, as subsystems such as the LCD which do
354 * their own DMA requests to the bus can cause the system to lockup
355 * if they where in the middle of requesting bus access.
357 * Disabling the LCD clock if the LCD is active is very dangerous,
358 * and therefore the bootloader should be careful to not enable
359 * the LCD clock if it is not needed.
362 /* install (and disable) the clocks we do not need immediately */
364 s3c_register_clocks(init_clocks_off
, ARRAY_SIZE(init_clocks_off
));
365 s3c_disable_clocks(init_clocks_off
, ARRAY_SIZE(init_clocks_off
));