/* linux/arch/arm/mach-s3c2410/s3c2410-clock.c
*
* Copyright (c) 2006 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
*
* S3C2410,S3C2440,S3C2442 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/delay.h>
#include <asm/hardware.h>
#include <asm/io.h>
#include <asm/arch/regs-clock.h>
#include <asm/arch/regs-gpio.h>
#include "clock.h"
#include "cpu.h"
int s3c2410_clkcon_enable(struct clk *clk, int enable)
{
unsigned int clocks = clk->ctrlbit;
unsigned long clkcon;
clkcon = __raw_readl(S3C2410_CLKCON);
if (enable)
clkcon |= clocks;
else
clkcon &= ~clocks;
/* ensure none of the special function bits set */
clkcon &= ~(S3C2410_CLKCON_IDLE|S3C2410_CLKCON_POWER);
__raw_writel(clkcon, S3C2410_CLKCON);
return 0;
}
static int s3c2410_upll_enable(struct clk *clk, int enable)
{
unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
unsigned long orig = clkslow;
if (enable)
clkslow &= ~S3C2410_CLKSLOW_UCLK_OFF;
else
clkslow |= S3C2410_CLKSLOW_UCLK_OFF;
__raw_writel(clkslow, S3C2410_CLKSLOW);
/* if we started the UPLL, then allow to settle */
if (enable && (orig & S3C2410_CLKSLOW_UCLK_OFF))
udelay(200);
return 0;
}
/* standard clock definitions */
static struct clk init_clocks_disable[] = {
{
.name = "nand",
.id = -1,
.parent = &clk_h,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_NAND,
}, {
.name = "sdi",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_SDI,
}, {
.name = "adc",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_ADC,
}, {
.name = "i2c",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_IIC,
}, {
.name = "iis",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_IIS,
}, {
.name = "spi",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_SPI,
}
};
static struct clk init_clocks[] = {
{
.name = "lcd",
.id = -1,
.parent = &clk_h,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_LCDC,
}, {
.name = "gpio",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_GPIO,
}, {
.name = "usb-host",
.id = -1,
.parent = &clk_h,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_USBH,
}, {
.name = "usb-device",
.id = -1,
.parent = &clk_h,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_USBD,
}, {
.name = "timers",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_PWMT,
}, {
.name = "uart",
.id = 0,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_UART0,
}, {
.name = "uart",
.id = 1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_UART1,
}, {
.name = "uart",
.id = 2,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_UART2,
}, {
.name = "rtc",
.id = -1,
.parent = &clk_p,
.enable = s3c2410_clkcon_enable,
.ctrlbit = S3C2410_CLKCON_RTC,
}, {
.name = "watchdog",
.id = -1,
.parent = &clk_p,
.ctrlbit = 0,
}, {
.name = "usb-bus-host",
.id = -1,
.parent = &clk_usb_bus,
}, {
.name = "usb-bus-gadget",
.id = -1,
.parent = &clk_usb_bus,
},
};
/* s3c2410_baseclk_add()
*
* Add all the clocks used by the s3c2410 or compatible CPUs
* such as the S3C2440 and S3C2442.
*
* We cannot use a system device as we are needed before any
* of the init-calls that initialise the devices are actually
* done.
*/
int __init s3c2410_baseclk_add(void)
{
unsigned long clkslow = __raw_readl(S3C2410_CLKSLOW);
unsigned long clkcon = __raw_readl(S3C2410_CLKCON);
struct clk *clkp;
struct clk *xtal;
int ret;
int ptr;
clk_upll.enable = s3c2410_upll_enable;
if (s3c24xx_register_clock(&clk_usb_bus) < 0)
printk(KERN_ERR "failed to register usb bus clock\n");
/* register clocks from clock array */
clkp = init_clocks;
for (ptr = 0; ptr < ARRAY_SIZE(init_clocks); ptr++, clkp++) {
/* ensure that we note the clock state */
clkp->usage = clkcon & clkp->ctrlbit ? 1 : 0;
ret = s3c24xx_register_clock(clkp);
if (ret < 0) {
printk(KERN_ERR "Failed to register clock %s (%d)\n",
clkp->name, ret);
}
}
/* We must be careful disabling the clocks we are not intending to
* be using at boot time, as subsytems 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 */
clkp = init_clocks_disable;
for (ptr = 0; ptr < ARRAY_SIZE(init_clocks_disable); ptr++, clkp++) {
ret = s3c24xx_register_clock(clkp);
if (ret < 0) {
printk(KERN_ERR "Failed to register clock %s (%d)\n",
clkp->name, ret);
}
s3c2410_clkcon_enable(clkp, 0);
}
/* show the clock-slow value */
xtal = clk_get(NULL, "xtal");
printk("CLOCK: Slow mode (%ld.%ld MHz), %s, MPLL %s, UPLL %s\n",
print_mhz(clk_get_rate(xtal) /
( 2 * S3C2410_CLKSLOW_GET_SLOWVAL(clkslow))),
(clkslow & S3C2410_CLKSLOW_SLOW) ? "slow" : "fast",
(clkslow & S3C2410_CLKSLOW_MPLL_OFF) ? "off" : "on",
(clkslow & S3C2410_CLKSLOW_UCLK_OFF) ? "off" : "on");
return 0;
}
