210 lines
4.2 KiB
C
210 lines
4.2 KiB
C
/*
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* Copyright (C) 2008 Sascha Hauer <s.hauer@pengutronix.de>, Pengutronix
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/kernel.h>
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#include <linux/device.h>
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#include <linux/list.h>
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#include <linux/math64.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <mach/hardware.h>
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/*
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* Very simple approach: We can't disable clocks, so we do
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* not need refcounting
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*/
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struct clk {
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struct list_head node;
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const char *name;
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unsigned long (*get_rate)(void);
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};
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/*
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* get the system pll clock in Hz
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*
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* mfi + mfn / (mfd +1)
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* f = 2 * f_ref * --------------------
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* pd + 1
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*/
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static unsigned long imx_decode_pll(unsigned int pll, u32 f_ref)
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{
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unsigned long long ll;
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unsigned long quot;
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u32 mfi = (pll >> 10) & 0xf;
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u32 mfn = pll & 0x3ff;
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u32 mfd = (pll >> 16) & 0x3ff;
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u32 pd = (pll >> 26) & 0xf;
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mfi = mfi <= 5 ? 5 : mfi;
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ll = 2 * (unsigned long long)f_ref *
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((mfi << 16) + (mfn << 16) / (mfd + 1));
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quot = (pd + 1) * (1 << 16);
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ll += quot / 2;
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do_div(ll, quot);
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return (unsigned long)ll;
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}
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static unsigned long imx_get_system_clk(void)
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{
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u32 f_ref = (CSCR & CSCR_SYSTEM_SEL) ? 16000000 : (CLK32 * 512);
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return imx_decode_pll(SPCTL0, f_ref);
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}
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static unsigned long imx_get_mcu_clk(void)
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{
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return imx_decode_pll(MPCTL0, CLK32 * 512);
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}
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/*
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* get peripheral clock 1 ( UART[12], Timer[12], PWM )
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*/
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static unsigned long imx_get_perclk1(void)
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{
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return imx_get_system_clk() / (((PCDR) & 0xf)+1);
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}
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/*
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* get peripheral clock 2 ( LCD, SD, SPI[12] )
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*/
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static unsigned long imx_get_perclk2(void)
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{
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return imx_get_system_clk() / (((PCDR>>4) & 0xf)+1);
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}
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/*
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* get peripheral clock 3 ( SSI )
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*/
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static unsigned long imx_get_perclk3(void)
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{
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return imx_get_system_clk() / (((PCDR>>16) & 0x7f)+1);
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}
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/*
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* get hclk ( SDRAM, CSI, Memory Stick, I2C, DMA )
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*/
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static unsigned long imx_get_hclk(void)
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{
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return imx_get_system_clk() / (((CSCR>>10) & 0xf)+1);
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}
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static struct clk clk_system_clk = {
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.name = "system_clk",
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.get_rate = imx_get_system_clk,
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};
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static struct clk clk_hclk = {
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.name = "hclk",
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.get_rate = imx_get_hclk,
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};
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static struct clk clk_mcu_clk = {
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.name = "mcu_clk",
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.get_rate = imx_get_mcu_clk,
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};
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static struct clk clk_perclk1 = {
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.name = "perclk1",
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.get_rate = imx_get_perclk1,
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};
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static struct clk clk_uart_clk = {
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.name = "uart_clk",
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.get_rate = imx_get_perclk1,
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};
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static struct clk clk_perclk2 = {
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.name = "perclk2",
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.get_rate = imx_get_perclk2,
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};
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static struct clk clk_perclk3 = {
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.name = "perclk3",
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.get_rate = imx_get_perclk3,
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};
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static struct clk *clks[] = {
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&clk_perclk1,
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&clk_perclk2,
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&clk_perclk3,
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&clk_system_clk,
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&clk_hclk,
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&clk_mcu_clk,
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&clk_uart_clk,
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};
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static LIST_HEAD(clocks);
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static DEFINE_MUTEX(clocks_mutex);
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struct clk *clk_get(struct device *dev, const char *id)
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{
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struct clk *p, *clk = ERR_PTR(-ENOENT);
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mutex_lock(&clocks_mutex);
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list_for_each_entry(p, &clocks, node) {
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if (!strcmp(p->name, id)) {
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clk = p;
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goto found;
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}
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}
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found:
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mutex_unlock(&clocks_mutex);
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return clk;
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}
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EXPORT_SYMBOL(clk_get);
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void clk_put(struct clk *clk)
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{
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}
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EXPORT_SYMBOL(clk_put);
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int clk_enable(struct clk *clk)
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{
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return 0;
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}
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EXPORT_SYMBOL(clk_enable);
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void clk_disable(struct clk *clk)
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{
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}
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EXPORT_SYMBOL(clk_disable);
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unsigned long clk_get_rate(struct clk *clk)
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{
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return clk->get_rate();
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}
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EXPORT_SYMBOL(clk_get_rate);
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int imx_clocks_init(void)
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{
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int i;
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mutex_lock(&clocks_mutex);
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for (i = 0; i < ARRAY_SIZE(clks); i++)
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list_add(&clks[i]->node, &clocks);
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mutex_unlock(&clocks_mutex);
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return 0;
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}
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