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/*
* Copyright (C) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
*
* 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/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/math64.h>
#include <linux/err.h>
#include <asm/io.h>
#include <asm/arch/imx-regs.h>
/*
* Very simple approach: We can't disable clocks, so we do
* not need refcounting
*/
struct clk {
struct list_head node;
const char *name;
unsigned long (*get_rate)(void);
};
/*
* get the system pll clock in Hz
*
* mfi + mfn / (mfd +1)
* f = 2 * f_ref * --------------------
* pd + 1
*/
static unsigned long imx_decode_pll(unsigned int pll, u32 f_ref)
{
unsigned long long ll;
unsigned long quot;
u32 mfi = (pll >> 10) & 0xf;
u32 mfn = pll & 0x3ff;
u32 mfd = (pll >> 16) & 0x3ff;
u32 pd = (pll >> 26) & 0xf;
mfi = mfi <= 5 ? 5 : mfi;
ll = 2 * (unsigned long long)f_ref *
((mfi << 16) + (mfn << 16) / (mfd + 1));
quot = (pd + 1) * (1 << 16);
ll += quot / 2;
do_div(ll, quot);
return (unsigned long)ll;
}
static unsigned long imx_get_system_clk(void)
{
u32 f_ref = (CSCR & CSCR_SYSTEM_SEL) ? 16000000 : (CLK32 * 512);
return imx_decode_pll(SPCTL0, f_ref);
}
static unsigned long imx_get_mcu_clk(void)
{
return imx_decode_pll(MPCTL0, CLK32 * 512);
}
/*
* get peripheral clock 1 ( UART[12], Timer[12], PWM )
*/
static unsigned long imx_get_perclk1(void)
{
return imx_get_system_clk() / (((PCDR) & 0xf)+1);
}
/*
* get peripheral clock 2 ( LCD, SD, SPI[12] )
*/
static unsigned long imx_get_perclk2(void)
{
return imx_get_system_clk() / (((PCDR>>4) & 0xf)+1);
}
/*
* get peripheral clock 3 ( SSI )
*/
static unsigned long imx_get_perclk3(void)
{
return imx_get_system_clk() / (((PCDR>>16) & 0x7f)+1);
}
/*
* get hclk ( SDRAM, CSI, Memory Stick, I2C, DMA )
*/
static unsigned long imx_get_hclk(void)
{
return imx_get_system_clk() / (((CSCR>>10) & 0xf)+1);
}
static struct clk clk_system_clk = {
.name = "system_clk",
.get_rate = imx_get_system_clk,
};
static struct clk clk_hclk = {
.name = "hclk",
.get_rate = imx_get_hclk,
};
static struct clk clk_mcu_clk = {
.name = "mcu_clk",
.get_rate = imx_get_mcu_clk,
};
static struct clk clk_perclk1 = {
.name = "perclk1",
.get_rate = imx_get_perclk1,
};
static struct clk clk_uart_clk = {
.name = "uart_clk",
.get_rate = imx_get_perclk1,
};
static struct clk clk_perclk2 = {
.name = "perclk2",
.get_rate = imx_get_perclk2,
};
static struct clk clk_perclk3 = {
.name = "perclk3",
.get_rate = imx_get_perclk3,
};
static struct clk *clks[] = {
&clk_perclk1,
&clk_perclk2,
&clk_perclk3,
&clk_system_clk,
&clk_hclk,
&clk_mcu_clk,
&clk_uart_clk,
};
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
struct clk *clk_get(struct device *dev, const char *id)
{
struct clk *p, *clk = ERR_PTR(-ENOENT);
mutex_lock(&clocks_mutex);
list_for_each_entry(p, &clocks, node) {
if (!strcmp(p->name, id)) {
clk = p;
goto found;
}
}
found:
mutex_unlock(&clocks_mutex);
return clk;
}
void clk_put(struct clk *clk)
{
}
int clk_enable(struct clk *clk)
{
return 0;
}
void clk_disable(struct clk *clk)
{
}
unsigned long clk_get_rate(struct clk *clk)
{
return clk->get_rate();
}
int imx_clocks_init(void)
{
int i;
mutex_lock(&clocks_mutex);
for (i = 0; i < ARRAY_SIZE(clks); i++)
list_add(&clks[i]->node, &clocks);
mutex_unlock(&clocks_mutex);
return 0;
}
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