drivers/soc/ti/ti_sci_pm_domains.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * TI SCI Generic Power Domain Driver
   4  *
   5  * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
   6  *      J Keerthy <j-keerthy@ti.com>
   7  *      Dave Gerlach <d-gerlach@ti.com>
   8  */
   9
  10 #include <linux/err.h>
  11 #include <linux/module.h>
  12 #include <linux/mutex.h>
  13 #include <linux/of.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/pm_domain.h>
  16 #include <linux/slab.h>
  17 #include <linux/soc/ti/ti_sci_protocol.h>
  18
  19 /**
  20  * struct ti_sci_genpd_dev_data: holds data needed for every device attached
  21  *                               to this genpd
  22  * @idx: index of the device that identifies it with the system
  23  *       control processor.
  24  */
  25 struct ti_sci_genpd_dev_data {
  26         int idx;
  27 };
  28
  29 /**
  30  * struct ti_sci_pm_domain: TI specific data needed for power domain
  31  * @ti_sci: handle to TI SCI protocol driver that provides ops to
  32  *          communicate with system control processor.
  33  * @dev: pointer to dev for the driver for devm allocs
  34  * @pd: generic_pm_domain for use with the genpd framework
  35  */
  36 struct ti_sci_pm_domain {
  37         const struct ti_sci_handle *ti_sci;
  38         struct device *dev;
  39         struct generic_pm_domain pd;
  40 };
  41
  42 #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd)
  43
  44 /**
  45  * ti_sci_dev_id(): get prepopulated ti_sci id from struct dev
  46  * @dev: pointer to device associated with this genpd
  47  *
  48  * Returns device_id stored from ti,sci_id property
  49  */
  50 static int ti_sci_dev_id(struct device *dev)
  51 {
  52         struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
  53         struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
  54
  55         return sci_dev_data->idx;
  56 }
  57
  58 /**
  59  * ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle
  60  * @dev: pointer to device associated with this genpd
  61  *
  62  * Returns ti_sci_handle to be used to communicate with system
  63  *         control processor.
  64  */
  65 static const struct ti_sci_handle *ti_sci_dev_to_sci_handle(struct device *dev)
  66 {
  67         struct generic_pm_domain *pd = pd_to_genpd(dev->pm_domain);
  68         struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(pd);
  69
  70         return ti_sci_genpd->ti_sci;
  71 }
  72
  73 /**
  74  * ti_sci_dev_start(): genpd device start hook called to turn device on
  75  * @dev: pointer to device associated with this genpd to be powered on
  76  */
  77 static int ti_sci_dev_start(struct device *dev)
  78 {
  79         const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
  80         int idx = ti_sci_dev_id(dev);
  81
  82         return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
  83 }
  84
  85 /**
  86  * ti_sci_dev_stop(): genpd device stop hook called to turn device off
  87  * @dev: pointer to device associated with this genpd to be powered off
  88  */
  89 static int ti_sci_dev_stop(struct device *dev)
  90 {
  91         const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
  92         int idx = ti_sci_dev_id(dev);
  93
  94         return ti_sci->ops.dev_ops.put_device(ti_sci, idx);
  95 }
  96
  97 static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
  98                                 struct device *dev)
  99 {
 100         struct device_node *np = dev->of_node;
 101         struct of_phandle_args pd_args;
 102         struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(domain);
 103         const struct ti_sci_handle *ti_sci = ti_sci_genpd->ti_sci;
 104         struct ti_sci_genpd_dev_data *sci_dev_data;
 105         struct generic_pm_domain_data *genpd_data;
 106         int idx, ret = 0;
 107
 108         ret = of_parse_phandle_with_args(np, "power-domains",
 109                                          "#power-domain-cells", 0, &pd_args);
 110         if (ret < 0)
 111                 return ret;
 112
 113         if (pd_args.args_count != 1)
 114                 return -EINVAL;
 115
 116         idx = pd_args.args[0];
 117
 118         /*
 119          * Check the validity of the requested idx, if the index is not valid
 120          * the PMMC will return a NAK here and we will not allocate it.
 121          */
 122         ret = ti_sci->ops.dev_ops.is_valid(ti_sci, idx);
 123         if (ret)
 124                 return -EINVAL;
 125
 126         sci_dev_data = kzalloc(sizeof(*sci_dev_data), GFP_KERNEL);
 127         if (!sci_dev_data)
 128                 return -ENOMEM;
 129
 130         sci_dev_data->idx = idx;
 131
 132         genpd_data = dev_gpd_data(dev);
 133         genpd_data->data = sci_dev_data;
 134
 135         return 0;
 136 }
 137
 138 static void ti_sci_pd_detach_dev(struct generic_pm_domain *domain,
 139                                  struct device *dev)
 140 {
 141         struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
 142         struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
 143
 144         kfree(sci_dev_data);
 145         genpd_data->data = NULL;
 146 }
 147
 148 static const struct of_device_id ti_sci_pm_domain_matches[] = {
 149         { .compatible = "ti,sci-pm-domain", },
 150         { },
 151 };
 152 MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches);
 153
 154 static int ti_sci_pm_domain_probe(struct platform_device *pdev)
 155 {
 156         struct device *dev = &pdev->dev;
 157         struct device_node *np = dev->of_node;
 158         struct ti_sci_pm_domain *ti_sci_pd;
 159         int ret;
 160
 161         ti_sci_pd = devm_kzalloc(dev, sizeof(*ti_sci_pd), GFP_KERNEL);
 162         if (!ti_sci_pd)
 163                 return -ENOMEM;
 164
 165         ti_sci_pd->ti_sci = devm_ti_sci_get_handle(dev);
 166         if (IS_ERR(ti_sci_pd->ti_sci))
 167                 return PTR_ERR(ti_sci_pd->ti_sci);
 168
 169         ti_sci_pd->dev = dev;
 170
 171         ti_sci_pd->pd.name = "ti_sci_pd";
 172
 173         ti_sci_pd->pd.attach_dev = ti_sci_pd_attach_dev;
 174         ti_sci_pd->pd.detach_dev = ti_sci_pd_detach_dev;
 175
 176         ti_sci_pd->pd.dev_ops.start = ti_sci_dev_start;
 177         ti_sci_pd->pd.dev_ops.stop = ti_sci_dev_stop;
 178
 179         pm_genpd_init(&ti_sci_pd->pd, NULL, true);
 180
 181         ret = of_genpd_add_provider_simple(np, &ti_sci_pd->pd);
 182
 183         return ret;
 184 }
 185
 186 static struct platform_driver ti_sci_pm_domains_driver = {
 187         .probe = ti_sci_pm_domain_probe,
 188         .driver = {
 189                 .name = "ti_sci_pm_domains",
 190                 .of_match_table = ti_sci_pm_domain_matches,
 191         },
 192 };
 193 module_platform_driver(ti_sci_pm_domains_driver);
 194 MODULE_LICENSE("GPL v2");
 195 MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver");
 196 MODULE_AUTHOR("Dave Gerlach");