arch/arm/mach-w90x900/clksel.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/arch/arm/mach-w90x900/clksel.c
   4  *
   5  * Copyright (c) 2008 Nuvoton technology corporation
   6  *
   7  * Wan ZongShun <mcuos.com@gmail.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/device.h>
  13 #include <linux/list.h>
  14 #include <linux/errno.h>
  15 #include <linux/err.h>
  16 #include <linux/string.h>
  17 #include <linux/clk.h>
  18 #include <linux/mutex.h>
  19 #include <linux/io.h>
  20
  21 #include <mach/hardware.h>
  22 #include <mach/regs-clock.h>
  23
  24 #define PLL0            0x00
  25 #define PLL1            0x01
  26 #define OTHER           0x02
  27 #define EXT             0x03
  28 #define MSOFFSET        0x0C
  29 #define ATAOFFSET       0x0a
  30 #define LCDOFFSET       0x06
  31 #define AUDOFFSET       0x04
  32 #define CPUOFFSET       0x00
  33
  34 static DEFINE_MUTEX(clksel_sem);
  35
  36 static void clock_source_select(const char *dev_id, unsigned int clkval)
  37 {
  38         unsigned int clksel, offset;
  39
  40         clksel = __raw_readl(REG_CLKSEL);
  41
  42         if (strcmp(dev_id, "nuc900-ms") == 0)
  43                 offset = MSOFFSET;
  44         else if (strcmp(dev_id, "nuc900-atapi") == 0)
  45                 offset = ATAOFFSET;
  46         else if (strcmp(dev_id, "nuc900-lcd") == 0)
  47                 offset = LCDOFFSET;
  48         else if (strcmp(dev_id, "nuc900-ac97") == 0)
  49                 offset = AUDOFFSET;
  50         else
  51                 offset = CPUOFFSET;
  52
  53         clksel &= ~(0x03 << offset);
  54         clksel |= (clkval << offset);
  55
  56         __raw_writel(clksel, REG_CLKSEL);
  57 }
  58
  59 void nuc900_clock_source(struct device *dev, unsigned char *src)
  60 {
  61         unsigned int clkval;
  62         const char *dev_id;
  63
  64         BUG_ON(!src);
  65         clkval = 0;
  66
  67         mutex_lock(&clksel_sem);
  68
  69         if (dev)
  70                 dev_id = dev_name(dev);
  71         else
  72                 dev_id = "cpufreq";
  73
  74         if (strcmp(src, "pll0") == 0)
  75                 clkval = PLL0;
  76         else if (strcmp(src, "pll1") == 0)
  77                 clkval = PLL1;
  78         else if (strcmp(src, "ext") == 0)
  79                 clkval = EXT;
  80         else if (strcmp(src, "oth") == 0)
  81                 clkval = OTHER;
  82
  83         clock_source_select(dev_id, clkval);
  84
  85         mutex_unlock(&clksel_sem);
  86 }
  87 EXPORT_SYMBOL(nuc900_clock_source);
  88