LXR linux/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
  11static 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
  33static 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
  55static 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
  77static struct reset_control_ops mmp_clk_reset_ops = {
  78        .assert         = mmp_clk_reset_assert,
  79        .deassert       = mmp_clk_reset_deassert,
  80};
  81
  82void 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}
 100