kernel/drivers/clk/versatile/clk-realview.c

   1 /*
   2  * Clock driver for the ARM RealView boards
   3  * Copyright (C) 2012 Linus Walleij
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  */
   9 #include <linux/clk.h>
  10 #include <linux/clkdev.h>
  11 #include <linux/err.h>
  12 #include <linux/io.h>
  13 #include <linux/clk-provider.h>
  14
  15 #include <mach/hardware.h>
  16 #include <mach/platform.h>
  17
  18 #include "clk-icst.h"
  19
  20 /*
  21  * Implementation of the ARM RealView clock trees.
  22  */
  23
  24 static const struct icst_params realview_oscvco_params = {
  25         .ref            = 24000000,
  26         .vco_max        = ICST307_VCO_MAX,
  27         .vco_min        = ICST307_VCO_MIN,
  28         .vd_min         = 4 + 8,
  29         .vd_max         = 511 + 8,
  30         .rd_min         = 1 + 2,
  31         .rd_max         = 127 + 2,
  32         .s2div          = icst307_s2div,
  33         .idx2s          = icst307_idx2s,
  34 };
  35
  36 static const struct clk_icst_desc __initdata realview_osc0_desc = {
  37         .params = &realview_oscvco_params,
  38         .vco_offset = REALVIEW_SYS_OSC0_OFFSET,
  39         .lock_offset = REALVIEW_SYS_LOCK_OFFSET,
  40 };
  41
  42 static const struct clk_icst_desc __initdata realview_osc4_desc = {
  43         .params = &realview_oscvco_params,
  44         .vco_offset = REALVIEW_SYS_OSC4_OFFSET,
  45         .lock_offset = REALVIEW_SYS_LOCK_OFFSET,
  46 };
  47
  48 /*
  49  * realview_clk_init() - set up the RealView clock tree
  50  */
  51 void __init realview_clk_init(void __iomem *sysbase, bool is_pb1176)
  52 {
  53         struct clk *clk;
  54
  55         /* APB clock dummy */
  56         clk = clk_register_fixed_rate(NULL, "apb_pclk", NULL, CLK_IS_ROOT, 0);
  57         clk_register_clkdev(clk, "apb_pclk", NULL);
  58
  59         /* 24 MHz clock */
  60         clk = clk_register_fixed_rate(NULL, "clk24mhz", NULL, CLK_IS_ROOT,
  61                                 24000000);
  62         clk_register_clkdev(clk, NULL, "dev:uart0");
  63         clk_register_clkdev(clk, NULL, "dev:uart1");
  64         clk_register_clkdev(clk, NULL, "dev:uart2");
  65         clk_register_clkdev(clk, NULL, "fpga:kmi0");
  66         clk_register_clkdev(clk, NULL, "fpga:kmi1");
  67         clk_register_clkdev(clk, NULL, "fpga:mmc0");
  68         clk_register_clkdev(clk, NULL, "dev:ssp0");
  69         if (is_pb1176) {
  70                 /*
  71                  * UART3 is on the dev chip in PB1176
  72                  * UART4 only exists in PB1176
  73                  */
  74                 clk_register_clkdev(clk, NULL, "dev:uart3");
  75                 clk_register_clkdev(clk, NULL, "dev:uart4");
  76         } else
  77                 clk_register_clkdev(clk, NULL, "fpga:uart3");
  78
  79
  80         /* 1 MHz clock */
  81         clk = clk_register_fixed_rate(NULL, "clk1mhz", NULL, CLK_IS_ROOT,
  82                                       1000000);
  83         clk_register_clkdev(clk, NULL, "sp804");
  84
  85         /* ICST VCO clock */
  86         if (is_pb1176)
  87                 clk = icst_clk_register(NULL, &realview_osc0_desc,
  88                                         "osc0", NULL, sysbase);
  89         else
  90                 clk = icst_clk_register(NULL, &realview_osc4_desc,
  91                                         "osc4", NULL, sysbase);
  92
  93         clk_register_clkdev(clk, NULL, "dev:clcd");
  94         clk_register_clkdev(clk, NULL, "issp:clcd");
  95 }