drivers/clk/at91/clk-plladiv.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2018 Microhip / Atmel Corporation
   4  *               Wenyou.Yang <wenyou.yang@microchip.com>
   5  */
   6
   7 #include <common.h>
   8 #include <clk-uclass.h>
   9 #include <dm/device.h>
  10 #include <linux/io.h>
  11 #include <mach/at91_pmc.h>
  12 #include "pmc.h"
  13
  14 static int at91_plladiv_clk_enable(struct clk *clk)
  15 {
  16         return 0;
  17 }
  18
  19 static ulong at91_plladiv_clk_get_rate(struct clk *clk)
  20 {
  21         struct pmc_platdata *plat = dev_get_platdata(clk->dev);
  22         struct at91_pmc *pmc = plat->reg_base;
  23         struct clk source;
  24         ulong clk_rate;
  25         int ret;
  26
  27         ret = clk_get_by_index(clk->dev, 0, &source);
  28         if (ret)
  29                 return -EINVAL;
  30
  31         clk_rate = clk_get_rate(&source);
  32         if (readl(&pmc->mckr) & AT91_PMC_MCKR_PLLADIV_2)
  33                 clk_rate /= 2;
  34
  35         return clk_rate;
  36 }
  37
  38 static ulong at91_plladiv_clk_set_rate(struct clk *clk, ulong rate)
  39 {
  40         struct pmc_platdata *plat = dev_get_platdata(clk->dev);
  41         struct at91_pmc *pmc = plat->reg_base;
  42         struct clk source;
  43         ulong parent_rate;
  44         int ret;
  45
  46         ret = clk_get_by_index(clk->dev, 0, &source);
  47         if (ret)
  48                 return -EINVAL;
  49
  50         parent_rate = clk_get_rate(&source);
  51         if ((parent_rate != rate) && ((parent_rate) / 2 != rate))
  52                 return -EINVAL;
  53
  54         if (parent_rate != rate) {
  55                 writel((readl(&pmc->mckr) | AT91_PMC_MCKR_PLLADIV_2),
  56                        &pmc->mckr);
  57         }
  58
  59         return 0;
  60 }
  61
  62 static struct clk_ops at91_plladiv_clk_ops = {
  63         .enable = at91_plladiv_clk_enable,
  64         .get_rate = at91_plladiv_clk_get_rate,
  65         .set_rate = at91_plladiv_clk_set_rate,
  66 };
  67
  68 static int at91_plladiv_clk_probe(struct udevice *dev)
  69 {
  70         return at91_pmc_core_probe(dev);
  71 }
  72
  73 static const struct udevice_id at91_plladiv_clk_match[] = {
  74         { .compatible = "atmel,at91sam9x5-clk-plldiv" },
  75         {}
  76 };
  77
  78 U_BOOT_DRIVER(at91_plladiv_clk) = {
  79         .name = "at91-plladiv-clk",
  80         .id = UCLASS_CLK,
  81         .of_match = at91_plladiv_clk_match,
  82         .probe = at91_plladiv_clk_probe,
  83         .platdata_auto_alloc_size = sizeof(struct pmc_platdata),
  84         .ops = &at91_plladiv_clk_ops,
  85 };