arch/arm/plat-s3c24xx/clock-dclk.c

   1 /* linux/arch/arm/plat-s3c24xx/clock-dclk.c
   2  *
   3  * Copyright (c) 2004-2008 Simtec Electronics
   4  *      Ben Dooks <ben@simtec.co.uk>
   5  *      http://armlinux.simtec.co.uk/
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * S3C24XX - definitions for DCLK and CLKOUT registers
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/clk.h>
  17 #include <linux/io.h>
  18
  19 #include <mach/regs-clock.h>
  20 #include <mach/regs-gpio.h>
  21
  22 #include <plat/clock.h>
  23 #include <plat/cpu.h>
  24
  25 /* clocks that could be registered by external code */
  26
  27 static int s3c24xx_dclk_enable(struct clk *clk, int enable)
  28 {
  29         unsigned long dclkcon = __raw_readl(S3C24XX_DCLKCON);
  30
  31         if (enable)
  32                 dclkcon |= clk->ctrlbit;
  33         else
  34                 dclkcon &= ~clk->ctrlbit;
  35
  36         __raw_writel(dclkcon, S3C24XX_DCLKCON);
  37
  38         return 0;
  39 }
  40
  41 static int s3c24xx_dclk_setparent(struct clk *clk, struct clk *parent)
  42 {
  43         unsigned long dclkcon;
  44         unsigned int uclk;
  45
  46         if (parent == &clk_upll)
  47                 uclk = 1;
  48         else if (parent == &clk_p)
  49                 uclk = 0;
  50         else
  51                 return -EINVAL;
  52
  53         clk->parent = parent;
  54
  55         dclkcon = __raw_readl(S3C24XX_DCLKCON);
  56
  57         if (clk->ctrlbit == S3C2410_DCLKCON_DCLK0EN) {
  58                 if (uclk)
  59                         dclkcon |= S3C2410_DCLKCON_DCLK0_UCLK;
  60                 else
  61                         dclkcon &= ~S3C2410_DCLKCON_DCLK0_UCLK;
  62         } else {
  63                 if (uclk)
  64                         dclkcon |= S3C2410_DCLKCON_DCLK1_UCLK;
  65                 else
  66                         dclkcon &= ~S3C2410_DCLKCON_DCLK1_UCLK;
  67         }
  68
  69         __raw_writel(dclkcon, S3C24XX_DCLKCON);
  70
  71         return 0;
  72 }
  73 static unsigned long s3c24xx_calc_div(struct clk *clk, unsigned long rate)
  74 {
  75         unsigned long div;
  76
  77         if ((rate == 0) || !clk->parent)
  78                 return 0;
  79
  80         div = clk_get_rate(clk->parent) / rate;
  81         if (div < 2)
  82                 div = 2;
  83         else if (div > 16)
  84                 div = 16;
  85
  86         return div;
  87 }
  88
  89 static unsigned long s3c24xx_round_dclk_rate(struct clk *clk,
  90         unsigned long rate)
  91 {
  92         unsigned long div = s3c24xx_calc_div(clk, rate);
  93
  94         if (div == 0)
  95                 return 0;
  96
  97         return clk_get_rate(clk->parent) / div;
  98 }
  99
 100 static int s3c24xx_set_dclk_rate(struct clk *clk, unsigned long rate)
 101 {
 102         unsigned long mask, data, div = s3c24xx_calc_div(clk, rate);
 103
 104         if (div == 0)
 105                 return -EINVAL;
 106
 107         if (clk == &s3c24xx_dclk0) {
 108                 mask = S3C2410_DCLKCON_DCLK0_DIV_MASK |
 109                         S3C2410_DCLKCON_DCLK0_CMP_MASK;
 110                 data = S3C2410_DCLKCON_DCLK0_DIV(div) |
 111                         S3C2410_DCLKCON_DCLK0_CMP((div + 1) / 2);
 112         } else if (clk == &s3c24xx_dclk1) {
 113                 mask = S3C2410_DCLKCON_DCLK1_DIV_MASK |
 114                         S3C2410_DCLKCON_DCLK1_CMP_MASK;
 115                 data = S3C2410_DCLKCON_DCLK1_DIV(div) |
 116                         S3C2410_DCLKCON_DCLK1_CMP((div + 1) / 2);
 117         } else
 118                 return -EINVAL;
 119
 120         clk->rate = clk_get_rate(clk->parent) / div;
 121         __raw_writel(((__raw_readl(S3C24XX_DCLKCON) & ~mask) | data),
 122                 S3C24XX_DCLKCON);
 123         return clk->rate;
 124 }
 125 static int s3c24xx_clkout_setparent(struct clk *clk, struct clk *parent)
 126 {
 127         unsigned long mask;
 128         unsigned long source;
 129
 130         /* calculate the MISCCR setting for the clock */
 131
 132         if (parent == &clk_mpll)
 133                 source = S3C2410_MISCCR_CLK0_MPLL;
 134         else if (parent == &clk_upll)
 135                 source = S3C2410_MISCCR_CLK0_UPLL;
 136         else if (parent == &clk_f)
 137                 source = S3C2410_MISCCR_CLK0_FCLK;
 138         else if (parent == &clk_h)
 139                 source = S3C2410_MISCCR_CLK0_HCLK;
 140         else if (parent == &clk_p)
 141                 source = S3C2410_MISCCR_CLK0_PCLK;
 142         else if (clk == &s3c24xx_clkout0 && parent == &s3c24xx_dclk0)
 143                 source = S3C2410_MISCCR_CLK0_DCLK0;
 144         else if (clk == &s3c24xx_clkout1 && parent == &s3c24xx_dclk1)
 145                 source = S3C2410_MISCCR_CLK0_DCLK0;
 146         else
 147                 return -EINVAL;
 148
 149         clk->parent = parent;
 150
 151         if (clk == &s3c24xx_clkout0)
 152                 mask = S3C2410_MISCCR_CLK0_MASK;
 153         else {
 154                 source <<= 4;
 155                 mask = S3C2410_MISCCR_CLK1_MASK;
 156         }
 157
 158         s3c2410_modify_misccr(mask, source);
 159         return 0;
 160 }
 161
 162 /* external clock definitions */
 163
 164 static struct clk_ops dclk_ops = {
 165         .set_parent     = s3c24xx_dclk_setparent,
 166         .set_rate       = s3c24xx_set_dclk_rate,
 167         .round_rate     = s3c24xx_round_dclk_rate,
 168 };
 169
 170 struct clk s3c24xx_dclk0 = {
 171         .name           = "dclk0",
 172         .ctrlbit        = S3C2410_DCLKCON_DCLK0EN,
 173         .enable         = s3c24xx_dclk_enable,
 174         .ops            = &dclk_ops,
 175 };
 176
 177 struct clk s3c24xx_dclk1 = {
 178         .name           = "dclk1",
 179         .ctrlbit        = S3C2410_DCLKCON_DCLK1EN,
 180         .enable         = s3c24xx_dclk_enable,
 181         .ops            = &dclk_ops,
 182 };
 183
 184 static struct clk_ops clkout_ops = {
 185         .set_parent     = s3c24xx_clkout_setparent,
 186 };
 187
 188 struct clk s3c24xx_clkout0 = {
 189         .name           = "clkout0",
 190         .ops            = &clkout_ops,
 191 };
 192
 193 struct clk s3c24xx_clkout1 = {
 194         .name           = "clkout1",
 195         .ops            = &clkout_ops,
 196 };