drivers/clk/mmp/reset.c

   1 #include <linux/slab.h>
   2 #include <linux/io.h>
   3 #include <linux/of.h>
   4 #include <linux/of_address.h>
   5 #include <linux/reset-controller.h>
   6
   7 #include "reset.h"
   8
   9 #define rcdev_to_unit(rcdev) container_of(rcdev, struct mmp_clk_reset_unit, rcdev)
  10
  11 static int mmp_of_reset_xlate(struct reset_controller_dev *rcdev,
  12                           const struct of_phandle_args *reset_spec)
  13 {
  14         struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  15         struct mmp_clk_reset_cell *cell;
  16         int i;
  17
  18         if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
  19                 return -EINVAL;
  20
  21         for (i = 0; i < rcdev->nr_resets; i++) {
  22                 cell = &unit->cells[i];
  23                 if (cell->clk_id == reset_spec->args[0])
  24                         break;
  25         }
  26
  27         if (i == rcdev->nr_resets)
  28                 return -EINVAL;
  29
  30         return i;
  31 }
  32
  33 static int mmp_clk_reset_assert(struct reset_controller_dev *rcdev,
  34                                 unsigned long id)
  35 {
  36         struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  37         struct mmp_clk_reset_cell *cell;
  38         unsigned long flags = 0;
  39         u32 val;
  40
  41         cell = &unit->cells[id];
  42         if (cell->lock)
  43                 spin_lock_irqsave(cell->lock, flags);
  44
  45         val = readl(cell->reg);
  46         val |= cell->bits;
  47         writel(val, cell->reg);
  48
  49         if (cell->lock)
  50                 spin_unlock_irqrestore(cell->lock, flags);
  51
  52         return 0;
  53 }
  54
  55 static int mmp_clk_reset_deassert(struct reset_controller_dev *rcdev,
  56                                 unsigned long id)
  57 {
  58         struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  59         struct mmp_clk_reset_cell *cell;
  60         unsigned long flags = 0;
  61         u32 val;
  62
  63         cell = &unit->cells[id];
  64         if (cell->lock)
  65                 spin_lock_irqsave(cell->lock, flags);
  66
  67         val = readl(cell->reg);
  68         val &= ~cell->bits;
  69         writel(val, cell->reg);
  70
  71         if (cell->lock)
  72                 spin_unlock_irqrestore(cell->lock, flags);
  73
  74         return 0;
  75 }
  76
  77 static const struct reset_control_ops mmp_clk_reset_ops = {
  78         .assert         = mmp_clk_reset_assert,
  79         .deassert       = mmp_clk_reset_deassert,
  80 };
  81
  82 void mmp_clk_reset_register(struct device_node *np,
  83                         struct mmp_clk_reset_cell *cells, int nr_resets)
  84 {
  85         struct mmp_clk_reset_unit *unit;
  86
  87         unit = kzalloc(sizeof(*unit), GFP_KERNEL);
  88         if (!unit)
  89                 return;
  90
  91         unit->cells = cells;
  92         unit->rcdev.of_reset_n_cells = 1;
  93         unit->rcdev.nr_resets = nr_resets;
  94         unit->rcdev.ops = &mmp_clk_reset_ops;
  95         unit->rcdev.of_node = np;
  96         unit->rcdev.of_xlate = mmp_of_reset_xlate;
  97
  98         reset_controller_register(&unit->rcdev);
  99 }