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kernel/linux-rt-4.4.41/drivers/clk/mmp/reset.c 2.16 KB
5113f6f70   김현기   kernel add
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  #include <linux/slab.h>
  #include <linux/io.h>
  #include <linux/of.h>
  #include <linux/of_address.h>
  #include <linux/reset-controller.h>
  
  #include "reset.h"
  
  #define rcdev_to_unit(rcdev) container_of(rcdev, struct mmp_clk_reset_unit, rcdev)
  
  static int mmp_of_reset_xlate(struct reset_controller_dev *rcdev,
  			  const struct of_phandle_args *reset_spec)
  {
  	struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  	struct mmp_clk_reset_cell *cell;
  	int i;
  
  	if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
  		return -EINVAL;
  
  	for (i = 0; i < rcdev->nr_resets; i++) {
  		cell = &unit->cells[i];
  		if (cell->clk_id == reset_spec->args[0])
  			break;
  	}
  
  	if (i == rcdev->nr_resets)
  		return -EINVAL;
  
  	return i;
  }
  
  static int mmp_clk_reset_assert(struct reset_controller_dev *rcdev,
  				unsigned long id)
  {
  	struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  	struct mmp_clk_reset_cell *cell;
  	unsigned long flags = 0;
  	u32 val;
  
  	cell = &unit->cells[id];
  	if (cell->lock)
  		spin_lock_irqsave(cell->lock, flags);
  
  	val = readl(cell->reg);
  	val |= cell->bits;
  	writel(val, cell->reg);
  
  	if (cell->lock)
  		spin_unlock_irqrestore(cell->lock, flags);
  
  	return 0;
  }
  
  static int mmp_clk_reset_deassert(struct reset_controller_dev *rcdev,
  				unsigned long id)
  {
  	struct mmp_clk_reset_unit *unit = rcdev_to_unit(rcdev);
  	struct mmp_clk_reset_cell *cell;
  	unsigned long flags = 0;
  	u32 val;
  
  	cell = &unit->cells[id];
  	if (cell->lock)
  		spin_lock_irqsave(cell->lock, flags);
  
  	val = readl(cell->reg);
  	val &= ~cell->bits;
  	writel(val, cell->reg);
  
  	if (cell->lock)
  		spin_unlock_irqrestore(cell->lock, flags);
  
  	return 0;
  }
  
  static struct reset_control_ops mmp_clk_reset_ops = {
  	.assert		= mmp_clk_reset_assert,
  	.deassert	= mmp_clk_reset_deassert,
  };
  
  void mmp_clk_reset_register(struct device_node *np,
  			struct mmp_clk_reset_cell *cells, int nr_resets)
  {
  	struct mmp_clk_reset_unit *unit;
  
  	unit = kzalloc(sizeof(*unit), GFP_KERNEL);
  	if (!unit)
  		return;
  
  	unit->cells = cells;
  	unit->rcdev.of_reset_n_cells = 1;
  	unit->rcdev.nr_resets = nr_resets;
  	unit->rcdev.ops = &mmp_clk_reset_ops;
  	unit->rcdev.of_node = np;
  	unit->rcdev.of_xlate = mmp_of_reset_xlate;
  
  	reset_controller_register(&unit->rcdev);
  }