drivers/soc/ti/ti_sci_pm_domains.c

   1 /*
   2  * TI SCI Generic Power Domain Driver
   3  *
   4  * Copyright (C) 2015-2017 Texas Instruments Incorporated - http://www.ti.com/
   5  *      J Keerthy <j-keerthy@ti.com>
   6  *      Dave Gerlach <d-gerlach@ti.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * version 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  */
  17
  18 #include <linux/err.h>
  19 #include <linux/module.h>
  20 #include <linux/mutex.h>
  21 #include <linux/of.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/pm_domain.h>
  24 #include <linux/slab.h>
  25 #include <linux/soc/ti/ti_sci_protocol.h>
  26
  27 /**
  28  * struct ti_sci_genpd_dev_data: holds data needed for every device attached
  29  *                               to this genpd
  30  * @idx: index of the device that identifies it with the system
  31  *       control processor.
  32  */
  33 struct ti_sci_genpd_dev_data {
  34         int idx;
  35 };
  36
  37 /**
  38  * struct ti_sci_pm_domain: TI specific data needed for power domain
  39  * @ti_sci: handle to TI SCI protocol driver that provides ops to
  40  *          communicate with system control processor.
  41  * @dev: pointer to dev for the driver for devm allocs
  42  * @pd: generic_pm_domain for use with the genpd framework
  43  */
  44 struct ti_sci_pm_domain {
  45         const struct ti_sci_handle *ti_sci;
  46         struct device *dev;
  47         struct generic_pm_domain pd;
  48 };
  49
  50 #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd)
  51
  52 /**
  53  * ti_sci_dev_id(): get prepopulated ti_sci id from struct dev
  54  * @dev: pointer to device associated with this genpd
  55  *
  56  * Returns device_id stored from ti,sci_id property
  57  */
  58 static int ti_sci_dev_id(struct device *dev)
  59 {
  60         struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
  61         struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
  62
  63         return sci_dev_data->idx;
  64 }
  65
  66 /**
  67  * ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle
  68  * @dev: pointer to device associated with this genpd
  69  *
  70  * Returns ti_sci_handle to be used to communicate with system
  71  *         control processor.
  72  */
  73 static const struct ti_sci_handle *ti_sci_dev_to_sci_handle(struct device *dev)
  74 {
  75         struct generic_pm_domain *pd = pd_to_genpd(dev->pm_domain);
  76         struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(pd);
  77
  78         return ti_sci_genpd->ti_sci;
  79 }
  80
  81 /**
  82  * ti_sci_dev_start(): genpd device start hook called to turn device on
  83  * @dev: pointer to device associated with this genpd to be powered on
  84  */
  85 static int ti_sci_dev_start(struct device *dev)
  86 {
  87         const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
  88         int idx = ti_sci_dev_id(dev);
  89
  90         return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
  91 }
  92
  93 /**
  94  * ti_sci_dev_stop(): genpd device stop hook called to turn device off
  95  * @dev: pointer to device associated with this genpd to be powered off
  96  */
  97 static int ti_sci_dev_stop(struct device *dev)
  98 {
  99         const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
 100         int idx = ti_sci_dev_id(dev);
 101
 102         return ti_sci->ops.dev_ops.put_device(ti_sci, idx);
 103 }
 104
 105 static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
 106                                 struct device *dev)
 107 {
 108         struct device_node *np = dev->of_node;
 109         struct of_phandle_args pd_args;
 110         struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(domain);
 111         const struct ti_sci_handle *ti_sci = ti_sci_genpd->ti_sci;
 112         struct ti_sci_genpd_dev_data *sci_dev_data;
 113         struct generic_pm_domain_data *genpd_data;
 114         int idx, ret = 0;
 115
 116         ret = of_parse_phandle_with_args(np, "power-domains",
 117                                          "#power-domain-cells", 0, &pd_args);
 118         if (ret < 0)
 119                 return ret;
 120
 121         if (pd_args.args_count != 1)
 122                 return -EINVAL;
 123
 124         idx = pd_args.args[0];
 125
 126         /*
 127          * Check the validity of the requested idx, if the index is not valid
 128          * the PMMC will return a NAK here and we will not allocate it.
 129          */
 130         ret = ti_sci->ops.dev_ops.is_valid(ti_sci, idx);
 131         if (ret)
 132                 return -EINVAL;
 133
 134         sci_dev_data = kzalloc(sizeof(*sci_dev_data), GFP_KERNEL);
 135         if (!sci_dev_data)
 136                 return -ENOMEM;
 137
 138         sci_dev_data->idx = idx;
 139
 140         genpd_data = dev_gpd_data(dev);
 141         genpd_data->data = sci_dev_data;
 142
 143         return 0;
 144 }
 145
 146 static void ti_sci_pd_detach_dev(struct generic_pm_domain *domain,
 147                                  struct device *dev)
 148 {
 149         struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
 150         struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
 151
 152         kfree(sci_dev_data);
 153         genpd_data->data = NULL;
 154 }
 155
 156 static const struct of_device_id ti_sci_pm_domain_matches[] = {
 157         { .compatible = "ti,sci-pm-domain", },
 158         { },
 159 };
 160 MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches);
 161
 162 static int ti_sci_pm_domain_probe(struct platform_device *pdev)
 163 {
 164         struct device *dev = &pdev->dev;
 165         struct device_node *np = dev->of_node;
 166         struct ti_sci_pm_domain *ti_sci_pd;
 167         int ret;
 168
 169         ti_sci_pd = devm_kzalloc(dev, sizeof(*ti_sci_pd), GFP_KERNEL);
 170         if (!ti_sci_pd)
 171                 return -ENOMEM;
 172
 173         ti_sci_pd->ti_sci = devm_ti_sci_get_handle(dev);
 174         if (IS_ERR(ti_sci_pd->ti_sci))
 175                 return PTR_ERR(ti_sci_pd->ti_sci);
 176
 177         ti_sci_pd->dev = dev;
 178
 179         ti_sci_pd->pd.attach_dev = ti_sci_pd_attach_dev;
 180         ti_sci_pd->pd.detach_dev = ti_sci_pd_detach_dev;
 181
 182         ti_sci_pd->pd.dev_ops.start = ti_sci_dev_start;
 183         ti_sci_pd->pd.dev_ops.stop = ti_sci_dev_stop;
 184
 185         pm_genpd_init(&ti_sci_pd->pd, NULL, true);
 186
 187         ret = of_genpd_add_provider_simple(np, &ti_sci_pd->pd);
 188
 189         return ret;
 190 }
 191
 192 static struct platform_driver ti_sci_pm_domains_driver = {
 193         .probe = ti_sci_pm_domain_probe,
 194         .driver = {
 195                 .name = "ti_sci_pm_domains",
 196                 .of_match_table = ti_sci_pm_domain_matches,
 197         },
 198 };
 199 module_platform_driver(ti_sci_pm_domains_driver);
 200 MODULE_LICENSE("GPL v2");
 201 MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver");
 202 MODULE_AUTHOR("Dave Gerlach");