diff options
Diffstat (limited to 'arch/arm/mach-s3c24xx/clock-s3c2440.c')
| -rw-r--r-- | arch/arm/mach-s3c24xx/clock-s3c2440.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c24xx/clock-s3c2440.c b/arch/arm/mach-s3c24xx/clock-s3c2440.c new file mode 100644 index 00000000..414364eb --- /dev/null +++ b/arch/arm/mach-s3c24xx/clock-s3c2440.c @@ -0,0 +1,194 @@ +/* linux/arch/arm/mach-s3c2440/clock.c + * + * Copyright (c) 2004-2005 Simtec Electronics + * http://armlinux.simtec.co.uk/ + * Ben Dooks <ben@simtec.co.uk> + * + * S3C2440 Clock 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/device.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/mutex.h> +#include <linux/clk.h> +#include <linux/io.h> +#include <linux/serial_core.h> + +#include <mach/hardware.h> +#include <linux/atomic.h> +#include <asm/irq.h> + +#include <mach/regs-clock.h> + +#include <plat/clock.h> +#include <plat/cpu.h> +#include <plat/regs-serial.h> + +/* S3C2440 extended clock support */ + +static unsigned long s3c2440_camif_upll_round(struct clk *clk, + unsigned long rate) +{ + unsigned long parent_rate = clk_get_rate(clk->parent); + int div; + + if (rate > parent_rate) + return parent_rate; + + /* note, we remove the +/- 1 calculations for the divisor */ + + div = (parent_rate / rate) / 2; + + if (div < 1) + div = 1; + else if (div > 16) + div = 16; + + return parent_rate / (div * 2); +} + +static int s3c2440_camif_upll_setrate(struct clk *clk, unsigned long rate) +{ + unsigned long parent_rate = clk_get_rate(clk->parent); + unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN); + + rate = s3c2440_camif_upll_round(clk, rate); + + camdivn &= ~(S3C2440_CAMDIVN_CAMCLK_SEL | S3C2440_CAMDIVN_CAMCLK_MASK); + + if (rate != parent_rate) { + camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL; + camdivn |= (((parent_rate / rate) / 2) - 1); + } + + __raw_writel(camdivn, S3C2440_CAMDIVN); + + return 0; +} + +/* Extra S3C2440 clocks */ + +static struct clk s3c2440_clk_cam = { + .name = "camif", + .enable = s3c2410_clkcon_enable, + .ctrlbit = S3C2440_CLKCON_CAMERA, +}; + +static struct clk s3c2440_clk_cam_upll = { + .name = "camif-upll", + .ops = &(struct clk_ops) { + .set_rate = s3c2440_camif_upll_setrate, + .round_rate = s3c2440_camif_upll_round, + }, +}; + +static struct clk s3c2440_clk_ac97 = { + .name = "ac97", + .enable = s3c2410_clkcon_enable, + .ctrlbit = S3C2440_CLKCON_CAMERA, +}; + +static unsigned long s3c2440_fclk_n_getrate(struct clk *clk) +{ + unsigned long ucon0, ucon1, ucon2, divisor; + + /* the fun of calculating the uart divisors on the s3c2440 */ + ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON); + ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON); + ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON); + + ucon0 &= S3C2440_UCON0_DIVMASK; + ucon1 &= S3C2440_UCON1_DIVMASK; + ucon2 &= S3C2440_UCON2_DIVMASK; + + if (ucon0 != 0) + divisor = (ucon0 >> S3C2440_UCON_DIVSHIFT) + 6; + else if (ucon1 != 0) + divisor = (ucon1 >> S3C2440_UCON_DIVSHIFT) + 21; + else if (ucon2 != 0) + divisor = (ucon2 >> S3C2440_UCON_DIVSHIFT) + 36; + else + /* manual calims 44, seems to be 9 */ + divisor = 9; + + return clk_get_rate(clk->parent) / divisor; +} + +static struct clk s3c2440_clk_fclk_n = { + .name = "fclk_n", + .parent = &clk_f, + .ops = &(struct clk_ops) { + .get_rate = s3c2440_fclk_n_getrate, + }, +}; + +static struct clk_lookup s3c2440_clk_lookup[] = { + CLKDEV_INIT(NULL, "clk_uart_baud1", &s3c24xx_uclk), + CLKDEV_INIT(NULL, "clk_uart_baud2", &clk_p), + CLKDEV_INIT(NULL, "clk_uart_baud3", &s3c2440_clk_fclk_n), +}; + +static int s3c2440_clk_add(struct device *dev, struct subsys_interface *sif) +{ + struct clk *clock_upll; + struct clk *clock_h; + struct clk *clock_p; + + clock_p = clk_get(NULL, "pclk"); + clock_h = clk_get(NULL, "hclk"); + clock_upll = clk_get(NULL, "upll"); + + if (IS_ERR(clock_p) || IS_ERR(clock_h) || IS_ERR(clock_upll)) { + printk(KERN_ERR "S3C2440: Failed to get parent clocks\n"); + return -EINVAL; + } + + s3c2440_clk_cam.parent = clock_h; + s3c2440_clk_ac97.parent = clock_p; + s3c2440_clk_cam_upll.parent = clock_upll; + s3c24xx_register_clock(&s3c2440_clk_fclk_n); + + s3c24xx_register_clock(&s3c2440_clk_ac97); + s3c24xx_register_clock(&s3c2440_clk_cam); + s3c24xx_register_clock(&s3c2440_clk_cam_upll); + clkdev_add_table(s3c2440_clk_lookup, ARRAY_SIZE(s3c2440_clk_lookup)); + + clk_disable(&s3c2440_clk_ac97); + clk_disable(&s3c2440_clk_cam); + + return 0; +} + +static struct subsys_interface s3c2440_clk_interface = { + .name = "s3c2440_clk", + .subsys = &s3c2440_subsys, + .add_dev = s3c2440_clk_add, +}; + +static __init int s3c24xx_clk_init(void) +{ + return subsys_interface_register(&s3c2440_clk_interface); +} + +arch_initcall(s3c24xx_clk_init); |