diff options
Diffstat (limited to 'arch/arm/mach-s3c2442/clock.c')
| -rw-r--r-- | arch/arm/mach-s3c2442/clock.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c2442/clock.c b/arch/arm/mach-s3c2442/clock.c new file mode 100644 index 000000000000..5b9e830ac4d3 --- /dev/null +++ b/arch/arm/mach-s3c2442/clock.c @@ -0,0 +1,171 @@ +/* linux/arch/arm/mach-s3c2442/clock.c + * + * Copyright (c) 2004-2005 Simtec Electronics + * http://armlinux.simtec.co.uk/ + * Ben Dooks <ben@simtec.co.uk> + * + * S3C2442 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/sysdev.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/mutex.h> +#include <linux/clk.h> + +#include <asm/hardware.h> +#include <asm/atomic.h> +#include <asm/irq.h> +#include <asm/io.h> + +#include <asm/arch/regs-clock.h> + +#include <asm/plat-s3c24xx/clock.h> +#include <asm/plat-s3c24xx/cpu.h> + +/* S3C2442 extended clock support */ + +static unsigned long s3c2442_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; + + div = parent_rate / rate; + + if (div == 3) + return parent_rate / 3; + + /* note, we remove the +/- 1 calculations for the divisor */ + + div /= 2; + + if (div < 1) + div = 1; + else if (div > 16) + div = 16; + + return parent_rate / (div * 2); +} + +static int s3c2442_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 = s3c2442_camif_upll_round(clk, rate); + + camdivn &= ~S3C2442_CAMDIVN_CAMCLK_DIV3; + + if (rate == parent_rate) { + camdivn &= ~S3C2440_CAMDIVN_CAMCLK_SEL; + } else if ((parent_rate / rate) == 3) { + camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL; + camdivn |= S3C2442_CAMDIVN_CAMCLK_DIV3; + } else { + camdivn &= ~S3C2440_CAMDIVN_CAMCLK_MASK; + camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL; + camdivn |= (((parent_rate / rate) / 2) - 1); + } + + __raw_writel(camdivn, S3C2440_CAMDIVN); + + return 0; +} + +/* Extra S3C2442 clocks */ + +static struct clk s3c2442_clk_cam = { + .name = "camif", + .id = -1, + .enable = s3c2410_clkcon_enable, + .ctrlbit = S3C2440_CLKCON_CAMERA, +}; + +static struct clk s3c2442_clk_cam_upll = { + .name = "camif-upll", + .id = -1, + .set_rate = s3c2442_camif_upll_setrate, + .round_rate = s3c2442_camif_upll_round, +}; + +static int s3c2442_clk_add(struct sys_device *sysdev) +{ + unsigned long camdivn = __raw_readl(S3C2440_CAMDIVN); + unsigned long clkdivn; + struct clk *clock_h; + struct clk *clock_p; + struct clk *clock_upll; + + printk("S3C2442: Clock Support, DVS %s\n", + (camdivn & S3C2440_CAMDIVN_DVSEN) ? "on" : "off"); + + 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 "S3C2442: Failed to get parent clocks\n"); + return -EINVAL; + } + + /* check rate of UPLL, and if it is near 96MHz, then change + * to using half the UPLL rate for the system */ + + if (clk_get_rate(clock_upll) > (94 * MHZ)) { + clk_usb_bus.rate = clk_get_rate(clock_upll) / 2; + + mutex_lock(&clocks_mutex); + + clkdivn = __raw_readl(S3C2410_CLKDIVN); + clkdivn |= S3C2440_CLKDIVN_UCLK; + __raw_writel(clkdivn, S3C2410_CLKDIVN); + + mutex_unlock(&clocks_mutex); + } + + s3c2442_clk_cam.parent = clock_h; + s3c2442_clk_cam_upll.parent = clock_upll; + + s3c24xx_register_clock(&s3c2442_clk_cam); + s3c24xx_register_clock(&s3c2442_clk_cam_upll); + + clk_disable(&s3c2442_clk_cam); + + return 0; +} + +static struct sysdev_driver s3c2442_clk_driver = { + .add = s3c2442_clk_add, +}; + +static __init int s3c2442_clk_init(void) +{ + return sysdev_driver_register(&s3c2442_sysclass, &s3c2442_clk_driver); +} + +arch_initcall(s3c2442_clk_init); |