drivers/clk/versatile/clk-impd1.c

   1 /*
   2  * Clock driver for the ARM Integrator/IM-PD1 board
   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-provider.h>
  10 #include <linux/clk.h>
  11 #include <linux/clkdev.h>
  12 #include <linux/err.h>
  13 #include <linux/io.h>
  14 #include <linux/platform_data/clk-integrator.h>
  15
  16 #include <mach/impd1.h>
  17
  18 #include "clk-icst.h"
  19
  20 struct impd1_clk {
  21         struct clk *vcoclk;
  22         struct clk *uartclk;
  23         struct clk_lookup *clks[3];
  24 };
  25
  26 static struct impd1_clk impd1_clks[4];
  27
  28 /*
  29  * There are two VCO's on the IM-PD1 but only one is used by the
  30  * kernel, that is why we are only implementing the control of
  31  * IMPD1_OSC1 here.
  32  */
  33
  34 static const struct icst_params impd1_vco_params = {
  35         .ref            = 24000000,     /* 24 MHz */
  36         .vco_max        = ICST525_VCO_MAX_3V,
  37         .vco_min        = ICST525_VCO_MIN,
  38         .vd_min         = 12,
  39         .vd_max         = 519,
  40         .rd_min         = 3,
  41         .rd_max         = 120,
  42         .s2div          = icst525_s2div,
  43         .idx2s          = icst525_idx2s,
  44 };
  45
  46 static const struct clk_icst_desc impd1_icst1_desc = {
  47         .params = &impd1_vco_params,
  48         .vco_offset = IMPD1_OSC1,
  49         .lock_offset = IMPD1_LOCK,
  50 };
  51
  52 /**
  53  * integrator_impd1_clk_init() - set up the integrator clock tree
  54  * @base: base address of the logic module (LM)
  55  * @id: the ID of this LM
  56  */
  57 void integrator_impd1_clk_init(void __iomem *base, unsigned int id)
  58 {
  59         struct impd1_clk *imc;
  60         struct clk *clk;
  61         int i;
  62
  63         if (id > 3) {
  64                 pr_crit("no more than 4 LMs can be attached\n");
  65                 return;
  66         }
  67         imc = &impd1_clks[id];
  68
  69         clk = icst_clk_register(NULL, &impd1_icst1_desc, base);
  70         imc->vcoclk = clk;
  71         imc->clks[0] = clkdev_alloc(clk, NULL, "lm%x:01000", id);
  72
  73         /* UART reference clock */
  74         clk = clk_register_fixed_rate(NULL, "uartclk", NULL, CLK_IS_ROOT,
  75                                 14745600);
  76         imc->uartclk = clk;
  77         imc->clks[1] = clkdev_alloc(clk, NULL, "lm%x:00100", id);
  78         imc->clks[2] = clkdev_alloc(clk, NULL, "lm%x:00200", id);
  79
  80         for (i = 0; i < ARRAY_SIZE(imc->clks); i++)
  81                 clkdev_add(imc->clks[i]);
  82 }
  83
  84 void integrator_impd1_clk_exit(unsigned int id)
  85 {
  86         int i;
  87         struct impd1_clk *imc;
  88
  89         if (id > 3)
  90                 return;
  91         imc = &impd1_clks[id];
  92
  93         for (i = 0; i < ARRAY_SIZE(imc->clks); i++)
  94                 clkdev_drop(imc->clks[i]);
  95         clk_unregister(imc->uartclk);
  96         clk_unregister(imc->vcoclk);
  97 }