arch/arm/mach-s3c2440/clock.c

   1 /* linux/arch/arm/mach-s3c2440/clock.c
   2  *
   3  * Copyright (c) 2004-2005 Simtec Electronics
   4  *      http://armlinux.simtec.co.uk/
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * S3C2440 Clock support
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22 */
  23
  24 #include <linux/init.h>
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/list.h>
  28 #include <linux/errno.h>
  29 #include <linux/err.h>
  30 #include <linux/device.h>
  31 #include <linux/interrupt.h>
  32 #include <linux/ioport.h>
  33 #include <linux/mutex.h>
  34 #include <linux/clk.h>
  35 #include <linux/io.h>
  36 #include <linux/serial_core.h>
  37
  38 #include <mach/hardware.h>
  39 #include <linux/atomic.h>
  40 #include <asm/irq.h>
  41
  42 #include <mach/regs-clock.h>
  43
  44 #include <plat/clock.h>
  45 #include <plat/cpu.h>
  46 #include <plat/regs-serial.h>
  47
  48 /* S3C2440 extended clock support */
  49
  50 static unsigned long s3c2440_camif_upll_round(struct clk *clk,
  51                                               unsigned long rate)
  52 {
  53         unsigned long parent_rate = clk_get_rate(clk->parent);
  54         int div;
  55
  56         if (rate > parent_rate)
  57                 return parent_rate;
  58
  59         /* note, we remove the +/- 1 calculations for the divisor */
  60
  61         div = (parent_rate / rate) / 2;
  62
  63         if (div < 1)
  64                 div = 1;
  65         else if (div > 16)
  66                 div = 16;
  67
  68         return parent_rate / (div * 2);
  69 }
  70
  71 static int s3c2440_camif_upll_setrate(struct clk *clk, unsigned long rate)
  72 {
  73         unsigned long parent_rate = clk_get_rate(clk->parent);
  74         unsigned long camdivn =  __raw_readl(S3C2440_CAMDIVN);
  75
  76         rate = s3c2440_camif_upll_round(clk, rate);
  77
  78         camdivn &= ~(S3C2440_CAMDIVN_CAMCLK_SEL | S3C2440_CAMDIVN_CAMCLK_MASK);
  79
  80         if (rate != parent_rate) {
  81                 camdivn |= S3C2440_CAMDIVN_CAMCLK_SEL;
  82                 camdivn |= (((parent_rate / rate) / 2) - 1);
  83         }
  84
  85         __raw_writel(camdivn, S3C2440_CAMDIVN);
  86
  87         return 0;
  88 }
  89
  90 /* Extra S3C2440 clocks */
  91
  92 static struct clk s3c2440_clk_cam = {
  93         .name           = "camif",
  94         .enable         = s3c2410_clkcon_enable,
  95         .ctrlbit        = S3C2440_CLKCON_CAMERA,
  96 };
  97
  98 static struct clk s3c2440_clk_cam_upll = {
  99         .name           = "camif-upll",
 100         .ops            = &(struct clk_ops) {
 101                 .set_rate       = s3c2440_camif_upll_setrate,
 102                 .round_rate     = s3c2440_camif_upll_round,
 103         },
 104 };
 105
 106 static struct clk s3c2440_clk_ac97 = {
 107         .name           = "ac97",
 108         .enable         = s3c2410_clkcon_enable,
 109         .ctrlbit        = S3C2440_CLKCON_CAMERA,
 110 };
 111
 112 static unsigned long  s3c2440_fclk_n_getrate(struct clk *clk)
 113 {
 114         unsigned long ucon0, ucon1, ucon2, divisor;
 115
 116         /* the fun of calculating the uart divisors on the s3c2440 */
 117         ucon0 = __raw_readl(S3C24XX_VA_UART0 + S3C2410_UCON);
 118         ucon1 = __raw_readl(S3C24XX_VA_UART1 + S3C2410_UCON);
 119         ucon2 = __raw_readl(S3C24XX_VA_UART2 + S3C2410_UCON);
 120
 121         ucon0 &= S3C2440_UCON0_DIVMASK;
 122         ucon1 &= S3C2440_UCON1_DIVMASK;
 123         ucon2 &= S3C2440_UCON2_DIVMASK;
 124
 125         if (ucon0 != 0)
 126                 divisor = (ucon0 >> S3C2440_UCON_DIVSHIFT) + 6;
 127         else if (ucon1 != 0)
 128                 divisor = (ucon1 >> S3C2440_UCON_DIVSHIFT) + 21;
 129         else if (ucon2 != 0)
 130                 divisor = (ucon2 >> S3C2440_UCON_DIVSHIFT) + 36;
 131         else
 132                 /* manual calims 44, seems to be 9 */
 133                 divisor = 9;
 134
 135         return clk_get_rate(clk->parent) / divisor;
 136 }
 137
 138 static struct clk s3c2440_clk_fclk_n = {
 139         .name           = "fclk_n",
 140         .parent         = &clk_f,
 141         .ops            = &(struct clk_ops) {
 142                 .get_rate       = s3c2440_fclk_n_getrate,
 143         },
 144 };
 145
 146 static struct clk_lookup s3c2440_clk_lookup[] = {
 147         CLKDEV_INIT(NULL, "clk_uart_baud1", &s3c24xx_uclk),
 148         CLKDEV_INIT(NULL, "clk_uart_baud2", &clk_p),
 149         CLKDEV_INIT(NULL, "clk_uart_baud3", &s3c2440_clk_fclk_n),
 150 };
 151
 152 static int s3c2440_clk_add(struct device *dev, struct subsys_interface *sif)
 153 {
 154         struct clk *clock_upll;
 155         struct clk *clock_h;
 156         struct clk *clock_p;
 157
 158         clock_p = clk_get(NULL, "pclk");
 159         clock_h = clk_get(NULL, "hclk");
 160         clock_upll = clk_get(NULL, "upll");
 161
 162         if (IS_ERR(clock_p) || IS_ERR(clock_h) || IS_ERR(clock_upll)) {
 163                 printk(KERN_ERR "S3C2440: Failed to get parent clocks\n");
 164                 return -EINVAL;
 165         }
 166
 167         s3c2440_clk_cam.parent = clock_h;
 168         s3c2440_clk_ac97.parent = clock_p;
 169         s3c2440_clk_cam_upll.parent = clock_upll;
 170         s3c24xx_register_clock(&s3c2440_clk_fclk_n);
 171
 172         s3c24xx_register_clock(&s3c2440_clk_ac97);
 173         s3c24xx_register_clock(&s3c2440_clk_cam);
 174         s3c24xx_register_clock(&s3c2440_clk_cam_upll);
 175         clkdev_add_table(s3c2440_clk_lookup, ARRAY_SIZE(s3c2440_clk_lookup));
 176
 177         clk_disable(&s3c2440_clk_ac97);
 178         clk_disable(&s3c2440_clk_cam);
 179
 180         return 0;
 181 }
 182
 183 static struct subsys_interface s3c2440_clk_interface = {
 184         .name           = "s3c2440_clk",
 185         .subsys         = &s3c2440_subsys,
 186         .add_dev        = s3c2440_clk_add,
 187 };
 188
 189 static __init int s3c24xx_clk_init(void)
 190 {
 191         return subsys_interface_register(&s3c2440_clk_interface);
 192 }
 193
 194 arch_initcall(s3c24xx_clk_init);