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