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                         /* additional clocks are optional */
  42                         if (i && PTR_ERR(pm->clocks[i]) == -ENOENT) {
  43                                 pm->clocks[i] = NULL;
  44                                 continue;
  45                         }
  46                         mfc_err("Failed to get clock: %s\n",
  47                                 pm->clk_names[i]);
  48                         return PTR_ERR(pm->clocks[i]);
  49                 }
  50         }
  51
  52         if (dev->variant->use_clock_gating)
  53                 pm->clock_gate = pm->clocks[0];
  54
  55         pm_runtime_enable(pm->device);
  56         atomic_set(&clk_ref, 0);
  57         return 0;
  58 }
  59
  60 void s5p_mfc_final_pm(struct s5p_mfc_dev *dev)
  61 {
  62         pm_runtime_disable(pm->device);
  63 }
  64
  65 int s5p_mfc_clock_on(void)
  66 {
  67         atomic_inc(&clk_ref);
  68         mfc_debug(3, "+ %d\n", atomic_read(&clk_ref));
  69
  70         return clk_enable(pm->clock_gate);
  71 }
  72
  73 void s5p_mfc_clock_off(void)
  74 {
  75         atomic_dec(&clk_ref);
  76         mfc_debug(3, "- %d\n", atomic_read(&clk_ref));
  77
  78         clk_disable(pm->clock_gate);
  79 }
  80
  81 int s5p_mfc_power_on(void)
  82 {
  83         int i, ret = 0;
  84
  85         ret = pm_runtime_get_sync(pm->device);
  86         if (ret < 0)
  87                 return ret;
  88
  89         /* clock control */
  90         for (i = 0; i < pm->num_clocks; i++) {
  91                 ret = clk_prepare_enable(pm->clocks[i]);
  92                 if (ret < 0) {
  93                         mfc_err("clock prepare failed for clock: %s\n",
  94                                 pm->clk_names[i]);
  95                         i++;
  96                         goto err;
  97                 }
  98         }
  99
 100         /* prepare for software clock gating */
 101         clk_disable(pm->clock_gate);
 102
 103         return 0;
 104 err:
 105         while (--i > 0)
 106                 clk_disable_unprepare(pm->clocks[i]);
 107         pm_runtime_put(pm->device);
 108         return ret;
 109 }
 110
 111 int s5p_mfc_power_off(void)
 112 {
 113         int i;
 114
 115         /* finish software clock gating */
 116         clk_enable(pm->clock_gate);
 117
 118         for (i = 0; i < pm->num_clocks; i++)
 119                 clk_disable_unprepare(pm->clocks[i]);
 120
 121         return pm_runtime_put_sync(pm->device);
 122 }
 123