drivers/irqchip/irq-gic-pm.c

   1 /*
   2  * Copyright (C) 2016 NVIDIA CORPORATION, All Rights Reserved.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #include <linux/module.h>
  17 #include <linux/clk.h>
  18 #include <linux/of_device.h>
  19 #include <linux/of_irq.h>
  20 #include <linux/irqchip/arm-gic.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/pm_clock.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/slab.h>
  25
  26 struct gic_clk_data {
  27         unsigned int num_clocks;
  28         const char *const *clocks;
  29 };
  30
  31 static int gic_runtime_resume(struct device *dev)
  32 {
  33         struct gic_chip_data *gic = dev_get_drvdata(dev);
  34         int ret;
  35
  36         ret = pm_clk_resume(dev);
  37         if (ret)
  38                 return ret;
  39
  40         /*
  41          * On the very first resume, the pointer to the driver data
  42          * will be NULL and this is intentional, because we do not
  43          * want to restore the GIC on the very first resume. So if
  44          * the pointer is not valid just return.
  45          */
  46         if (!gic)
  47                 return 0;
  48
  49         gic_dist_restore(gic);
  50         gic_cpu_restore(gic);
  51
  52         return 0;
  53 }
  54
  55 static int gic_runtime_suspend(struct device *dev)
  56 {
  57         struct gic_chip_data *gic = dev_get_drvdata(dev);
  58
  59         gic_dist_save(gic);
  60         gic_cpu_save(gic);
  61
  62         return pm_clk_suspend(dev);
  63 }
  64
  65 static int gic_get_clocks(struct device *dev, const struct gic_clk_data *data)
  66 {
  67         struct clk *clk;
  68         unsigned int i;
  69         int ret;
  70
  71         if (!dev || !data)
  72                 return -EINVAL;
  73
  74         ret = pm_clk_create(dev);
  75         if (ret)
  76                 return ret;
  77
  78         for (i = 0; i < data->num_clocks; i++) {
  79                 clk = of_clk_get_by_name(dev->of_node, data->clocks[i]);
  80                 if (IS_ERR(clk)) {
  81                         dev_err(dev, "failed to get clock %s\n",
  82                                 data->clocks[i]);
  83                         ret = PTR_ERR(clk);
  84                         goto error;
  85                 }
  86
  87                 ret = pm_clk_add_clk(dev, clk);
  88                 if (ret) {
  89                         dev_err(dev, "failed to add clock at index %d\n", i);
  90                         clk_put(clk);
  91                         goto error;
  92                 }
  93         }
  94
  95         return 0;
  96
  97 error:
  98         pm_clk_destroy(dev);
  99
 100         return ret;
 101 }
 102
 103 static int gic_probe(struct platform_device *pdev)
 104 {
 105         struct device *dev = &pdev->dev;
 106         const struct gic_clk_data *data;
 107         struct gic_chip_data *gic;
 108         int ret, irq;
 109
 110         data = of_device_get_match_data(&pdev->dev);
 111         if (!data) {
 112                 dev_err(&pdev->dev, "no device match found\n");
 113                 return -ENODEV;
 114         }
 115
 116         irq = irq_of_parse_and_map(dev->of_node, 0);
 117         if (!irq) {
 118                 dev_err(dev, "no parent interrupt found!\n");
 119                 return -EINVAL;
 120         }
 121
 122         ret = gic_get_clocks(dev, data);
 123         if (ret)
 124                 goto irq_dispose;
 125
 126         pm_runtime_enable(dev);
 127
 128         ret = pm_runtime_get_sync(dev);
 129         if (ret < 0)
 130                 goto rpm_disable;
 131
 132         ret = gic_of_init_child(dev, &gic, irq);
 133         if (ret)
 134                 goto rpm_put;
 135
 136         platform_set_drvdata(pdev, gic);
 137
 138         pm_runtime_put(dev);
 139
 140         dev_info(dev, "GIC IRQ controller registered\n");
 141
 142         return 0;
 143
 144 rpm_put:
 145         pm_runtime_put_sync(dev);
 146 rpm_disable:
 147         pm_runtime_disable(dev);
 148         pm_clk_destroy(dev);
 149 irq_dispose:
 150         irq_dispose_mapping(irq);
 151
 152         return ret;
 153 }
 154
 155 static const struct dev_pm_ops gic_pm_ops = {
 156         SET_RUNTIME_PM_OPS(gic_runtime_suspend,
 157                            gic_runtime_resume, NULL)
 158 };
 159
 160 static const char * const gic400_clocks[] = {
 161         "clk",
 162 };
 163
 164 static const struct gic_clk_data gic400_data = {
 165         .num_clocks = ARRAY_SIZE(gic400_clocks),
 166         .clocks = gic400_clocks,
 167 };
 168
 169 static const struct of_device_id gic_match[] = {
 170         { .compatible = "nvidia,tegra210-agic", .data = &gic400_data },
 171         {},
 172 };
 173 MODULE_DEVICE_TABLE(of, gic_match);
 174
 175 static struct platform_driver gic_driver = {
 176         .probe          = gic_probe,
 177         .driver         = {
 178                 .name   = "gic",
 179                 .of_match_table = gic_match,
 180                 .pm     = &gic_pm_ops,
 181         }
 182 };
 183
 184 builtin_platform_driver(gic_driver);