drivers/media/platform/s5p-mfc/s5p_mfc_pm.c

   1 /*
   2  * linux/drivers/media/platform/s5p-mfc/s5p_mfc_pm.c
   3  *
   4  * Copyright (c) 2010 Samsung Electronics Co., Ltd.
   5  *              http://www.samsung.com/
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <linux/clk.h>
  14 #include <linux/err.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pm_runtime.h>
  17 #include "s5p_mfc_common.h"
  18 #include "s5p_mfc_debug.h"
  19 #include "s5p_mfc_pm.h"
  20
  21 static struct s5p_mfc_pm *pm;
  22 static struct s5p_mfc_dev *p_dev;
  23 static atomic_t clk_ref;
  24
  25 int s5p_mfc_init_pm(struct s5p_mfc_dev *dev)
  26 {
  27         int i;
  28
  29         pm = &dev->pm;
  30         p_dev = dev;
  31
  32         pm->num_clocks = dev->variant->num_clocks;
  33         pm->clk_names = dev->variant->clk_names;
  34         pm->device = &dev->plat_dev->dev;
  35         pm->clock_gate = NULL;
  36
  37         /* clock control */
  38         for (i = 0; i < pm->num_clocks; i++) {
  39                 pm->clocks[i] = devm_clk_get(pm->device, pm->clk_names[i]);
  40                 if (IS_ERR(pm->clocks[i])) {
  41                         mfc_err("Failed to get clock: %s\n",
  42                                 pm->clk_names[i]);
  43                         return PTR_ERR(pm->clocks[i]);
  44                 }
  45         }
  46
  47         if (dev->variant->use_clock_gating)
  48                 pm->clock_gate = pm->clocks[0];
  49
  50         pm_runtime_enable(pm->device);
  51         atomic_set(&clk_ref, 0);
  52         return 0;
  53 }
  54
  55 void s5p_mfc_final_pm(struct s5p_mfc_dev *dev)
  56 {
  57         pm_runtime_disable(pm->device);
  58 }
  59
  60 int s5p_mfc_clock_on(void)
  61 {
  62         atomic_inc(&clk_ref);
  63         mfc_debug(3, "+ %d\n", atomic_read(&clk_ref));
  64
  65         return clk_enable(pm->clock_gate);
  66 }
  67
  68 void s5p_mfc_clock_off(void)
  69 {
  70         atomic_dec(&clk_ref);
  71         mfc_debug(3, "- %d\n", atomic_read(&clk_ref));
  72
  73         clk_disable(pm->clock_gate);
  74 }
  75
  76 int s5p_mfc_power_on(void)
  77 {
  78         int i, ret = 0;
  79
  80         ret = pm_runtime_get_sync(pm->device);
  81         if (ret < 0)
  82                 return ret;
  83
  84         /* clock control */
  85         for (i = 0; i < pm->num_clocks; i++) {
  86                 ret = clk_prepare_enable(pm->clocks[i]);
  87                 if (ret < 0) {
  88                         mfc_err("clock prepare failed for clock: %s\n",
  89                                 pm->clk_names[i]);
  90                         i++;
  91                         goto err;
  92                 }
  93         }
  94
  95         /* prepare for software clock gating */
  96         clk_disable(pm->clock_gate);
  97
  98         return 0;
  99 err:
 100         while (--i > 0)
 101                 clk_disable_unprepare(pm->clocks[i]);
 102         pm_runtime_put(pm->device);
 103         return ret;
 104 }
 105
 106 int s5p_mfc_power_off(void)
 107 {
 108         int i;
 109
 110         /* finish software clock gating */
 111         clk_enable(pm->clock_gate);
 112
 113         for (i = 0; i < pm->num_clocks; i++)
 114                 clk_disable_unprepare(pm->clocks[i]);
 115
 116         return pm_runtime_put_sync(pm->device);
 117 }
 118