drivers/cpufreq/s3c2410-cpufreq.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2006-2008 Simtec Electronics
   4  *      http://armlinux.simtec.co.uk/
   5  *      Ben Dooks <ben@simtec.co.uk>
   6  *
   7  * S3C2410 CPU Frequency scaling
   8 */
   9
  10 #include <linux/init.h>
  11 #include <linux/module.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/ioport.h>
  14 #include <linux/cpufreq.h>
  15 #include <linux/device.h>
  16 #include <linux/clk.h>
  17 #include <linux/err.h>
  18 #include <linux/io.h>
  19
  20 #include <asm/mach/arch.h>
  21 #include <asm/mach/map.h>
  22
  23 #include <mach/regs-clock.h>
  24
  25 #include <plat/cpu.h>
  26 #include <plat/cpu-freq-core.h>
  27
  28 /* Note, 2410A has an extra mode for 1:4:4 ratio, bit 2 of CLKDIV */
  29
  30 static void s3c2410_cpufreq_setdivs(struct s3c_cpufreq_config *cfg)
  31 {
  32         u32 clkdiv = 0;
  33
  34         if (cfg->divs.h_divisor == 2)
  35                 clkdiv |= S3C2410_CLKDIVN_HDIVN;
  36
  37         if (cfg->divs.p_divisor != cfg->divs.h_divisor)
  38                 clkdiv |= S3C2410_CLKDIVN_PDIVN;
  39
  40         __raw_writel(clkdiv, S3C2410_CLKDIVN);
  41 }
  42
  43 static int s3c2410_cpufreq_calcdivs(struct s3c_cpufreq_config *cfg)
  44 {
  45         unsigned long hclk, fclk, pclk;
  46         unsigned int hdiv, pdiv;
  47         unsigned long hclk_max;
  48
  49         fclk = cfg->freq.fclk;
  50         hclk_max = cfg->max.hclk;
  51
  52         cfg->freq.armclk = fclk;
  53
  54         s3c_freq_dbg("%s: fclk is %lu, max hclk %lu\n",
  55                       __func__, fclk, hclk_max);
  56
  57         hdiv = (fclk > cfg->max.hclk) ? 2 : 1;
  58         hclk = fclk / hdiv;
  59
  60         if (hclk > cfg->max.hclk) {
  61                 s3c_freq_dbg("%s: hclk too big\n", __func__);
  62                 return -EINVAL;
  63         }
  64
  65         pdiv = (hclk > cfg->max.pclk) ? 2 : 1;
  66         pclk = hclk / pdiv;
  67
  68         if (pclk > cfg->max.pclk) {
  69                 s3c_freq_dbg("%s: pclk too big\n", __func__);
  70                 return -EINVAL;
  71         }
  72
  73         pdiv *= hdiv;
  74
  75         /* record the result */
  76         cfg->divs.p_divisor = pdiv;
  77         cfg->divs.h_divisor = hdiv;
  78
  79         return 0;
  80 }
  81
  82 static struct s3c_cpufreq_info s3c2410_cpufreq_info = {
  83         .max            = {
  84                 .fclk   = 200000000,
  85                 .hclk   = 100000000,
  86                 .pclk   =  50000000,
  87         },
  88
  89         /* transition latency is about 5ms worst-case, so
  90          * set 10ms to be sure */
  91         .latency        = 10000000,
  92
  93         .locktime_m     = 150,
  94         .locktime_u     = 150,
  95         .locktime_bits  = 12,
  96
  97         .need_pll       = 1,
  98
  99         .name           = "s3c2410",
 100         .calc_iotiming  = s3c2410_iotiming_calc,
 101         .set_iotiming   = s3c2410_iotiming_set,
 102         .get_iotiming   = s3c2410_iotiming_get,
 103
 104         .set_fvco       = s3c2410_set_fvco,
 105         .set_refresh    = s3c2410_cpufreq_setrefresh,
 106         .set_divs       = s3c2410_cpufreq_setdivs,
 107         .calc_divs      = s3c2410_cpufreq_calcdivs,
 108
 109         .debug_io_show  = s3c_cpufreq_debugfs_call(s3c2410_iotiming_debugfs),
 110 };
 111
 112 static int s3c2410_cpufreq_add(struct device *dev,
 113                                struct subsys_interface *sif)
 114 {
 115         return s3c_cpufreq_register(&s3c2410_cpufreq_info);
 116 }
 117
 118 static struct subsys_interface s3c2410_cpufreq_interface = {
 119         .name           = "s3c2410_cpufreq",
 120         .subsys         = &s3c2410_subsys,
 121         .add_dev        = s3c2410_cpufreq_add,
 122 };
 123
 124 static int __init s3c2410_cpufreq_init(void)
 125 {
 126         return subsys_interface_register(&s3c2410_cpufreq_interface);
 127 }
 128 arch_initcall(s3c2410_cpufreq_init);
 129
 130 static int s3c2410a_cpufreq_add(struct device *dev,
 131                                 struct subsys_interface *sif)
 132 {
 133         /* alter the maximum freq settings for S3C2410A. If a board knows
 134          * it only has a maximum of 200, then it should register its own
 135          * limits. */
 136
 137         s3c2410_cpufreq_info.max.fclk = 266000000;
 138         s3c2410_cpufreq_info.max.hclk = 133000000;
 139         s3c2410_cpufreq_info.max.pclk =  66500000;
 140         s3c2410_cpufreq_info.name = "s3c2410a";
 141
 142         return s3c2410_cpufreq_add(dev, sif);
 143 }
 144
 145 static struct subsys_interface s3c2410a_cpufreq_interface = {
 146         .name           = "s3c2410a_cpufreq",
 147         .subsys         = &s3c2410a_subsys,
 148         .add_dev        = s3c2410a_cpufreq_add,
 149 };
 150
 151 static int __init s3c2410a_cpufreq_init(void)
 152 {
 153         return subsys_interface_register(&s3c2410a_cpufreq_interface);
 154 }
 155 arch_initcall(s3c2410a_cpufreq_init);