diff options
Diffstat (limited to 'arch/arm/mach-s3c2410/s3c2410-clock.c')
| -rw-r--r-- | arch/arm/mach-s3c2410/s3c2410-clock.c | 263 |
1 files changed, 263 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2410/s3c2410-clock.c b/arch/arm/mach-s3c2410/s3c2410-clock.c new file mode 100644 index 00000000000..fd17c60e113 --- /dev/null +++ b/arch/arm/mach-s3c2410/s3c2410-clock.c @@ -0,0 +1,263 @@ +/* linux/arch/arm/mach-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, + } +}; + +/* 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; +} |