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 #include <dt-bindings/soc/ti,sci_pm_domain.h>
  19
  20 /**
  21  * struct ti_sci_genpd_dev_data: holds data needed for every device attached
  22  *                               to this genpd
  23  * @idx: index of the device that identifies it with the system
  24  *       control processor.
  25  * @exclusive: Permissions for exclusive request or shared request of the
  26  *             device.
  27  */
  28 struct ti_sci_genpd_dev_data {
  29         int idx;
  30         u8 exclusive;
  31 };
  32
  33 /**
  34  * struct ti_sci_pm_domain: TI specific data needed for power domain
  35  * @ti_sci: handle to TI SCI protocol driver that provides ops to
  36  *          communicate with system control processor.
  37  * @dev: pointer to dev for the driver for devm allocs
  38  * @pd: generic_pm_domain for use with the genpd framework
  39  */
  40 struct ti_sci_pm_domain {
  41         const struct ti_sci_handle *ti_sci;
  42         struct device *dev;
  43         struct generic_pm_domain pd;
  44 };
  45
  46 #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd)
  47
  48 /**
  49  * ti_sci_dev_id(): get prepopulated ti_sci id from struct dev
  50  * @dev: pointer to device associated with this genpd
  51  *
  52  * Returns device_id stored from ti,sci_id property
  53  */
  54 static int ti_sci_dev_id(struct device *dev)
  55 {
  56         struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
  57         struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
  58
  59         return sci_dev_data->idx;
  60 }
  61
  62 static u8 is_ti_sci_dev_exclusive(struct device *dev)
  63 {
  64         struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
  65         struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
  66
  67         return sci_dev_data->exclusive;
  68 }
  69
  70 /**
  71  * ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle
  72  * @dev: pointer to device associated with this genpd
  73  *
  74  * Returns ti_sci_handle to be used to communicate with system
  75  *         control processor.
  76  */
  77 static const struct ti_sci_handle *ti_sci_dev_to_sci_handle(struct device *dev)
  78 {
  79         struct generic_pm_domain *pd = pd_to_genpd(dev->pm_domain);
  80         struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(pd);
  81
  82         return ti_sci_genpd->ti_sci;
  83 }
  84
  85 /**
  86  * ti_sci_dev_start(): genpd device start hook called to turn device on
  87  * @dev: pointer to device associated with this genpd to be powered on
  88  */
  89 static int ti_sci_dev_start(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         if (is_ti_sci_dev_exclusive(dev))
  95                 return ti_sci->ops.dev_ops.get_device_exclusive(ti_sci, idx);
  96         else
  97                 return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
  98 }
  99
 100 /**
 101  * ti_sci_dev_stop(): genpd device stop hook called to turn device off
 102  * @dev: pointer to device associated with this genpd to be powered off
 103  */
 104 static int ti_sci_dev_stop(struct device *dev)
 105 {
 106         const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
 107         int idx = ti_sci_dev_id(dev);
 108
 109         return ti_sci->ops.dev_ops.put_device(ti_sci, idx);
 110 }
 111
 112 static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
 113                                 struct device *dev)
 114 {
 115         struct device_node *np = dev->of_node;
 116         struct of_phandle_args pd_args;
 117         struct ti_sci_pm_domain *ti_sci_genpd = genpd_to_ti_sci_pd(domain);
 118         const struct ti_sci_handle *ti_sci = ti_sci_genpd->ti_sci;
 119         struct ti_sci_genpd_dev_data *sci_dev_data;
 120         struct generic_pm_domain_data *genpd_data;
 121         int idx, ret = 0;
 122
 123         ret = of_parse_phandle_with_args(np, "power-domains",
 124                                          "#power-domain-cells", 0, &pd_args);
 125         if (ret < 0)
 126                 return ret;
 127
 128         if (pd_args.args_count != 1 && pd_args.args_count != 2)
 129                 return -EINVAL;
 130
 131         idx = pd_args.args[0];
 132
 133         /*
 134          * Check the validity of the requested idx, if the index is not valid
 135          * the PMMC will return a NAK here and we will not allocate it.
 136          */
 137         ret = ti_sci->ops.dev_ops.is_valid(ti_sci, idx);
 138         if (ret)
 139                 return -EINVAL;
 140
 141         sci_dev_data = kzalloc(sizeof(*sci_dev_data), GFP_KERNEL);
 142         if (!sci_dev_data)
 143                 return -ENOMEM;
 144
 145         sci_dev_data->idx = idx;
 146         /* Enable the exclusive permissions by default */
 147         sci_dev_data->exclusive = TI_SCI_PD_EXCLUSIVE;
 148         if (pd_args.args_count == 2)
 149                 sci_dev_data->exclusive = pd_args.args[1] & 0x1;
 150
 151         genpd_data = dev_gpd_data(dev);
 152         genpd_data->data = sci_dev_data;
 153
 154         return 0;
 155 }
 156
 157 static void ti_sci_pd_detach_dev(struct generic_pm_domain *domain,
 158                                  struct device *dev)
 159 {
 160         struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
 161         struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
 162
 163         kfree(sci_dev_data);
 164         genpd_data->data = NULL;
 165 }
 166
 167 static const struct of_device_id ti_sci_pm_domain_matches[] = {
 168         { .compatible = "ti,sci-pm-domain", },
 169         { },
 170 };
 171 MODULE_DEVICE_TABLE(of, ti_sci_pm_domain_matches);
 172
 173 static int ti_sci_pm_domain_probe(struct platform_device *pdev)
 174 {
 175         struct device *dev = &pdev->dev;
 176         struct device_node *np = dev->of_node;
 177         struct ti_sci_pm_domain *ti_sci_pd;
 178         int ret;
 179
 180         ti_sci_pd = devm_kzalloc(dev, sizeof(*ti_sci_pd), GFP_KERNEL);
 181         if (!ti_sci_pd)
 182                 return -ENOMEM;
 183
 184         ti_sci_pd->ti_sci = devm_ti_sci_get_handle(dev);
 185         if (IS_ERR(ti_sci_pd->ti_sci))
 186                 return PTR_ERR(ti_sci_pd->ti_sci);
 187
 188         ti_sci_pd->dev = dev;
 189
 190         ti_sci_pd->pd.name = "ti_sci_pd";
 191
 192         ti_sci_pd->pd.attach_dev = ti_sci_pd_attach_dev;
 193         ti_sci_pd->pd.detach_dev = ti_sci_pd_detach_dev;
 194
 195         ti_sci_pd->pd.dev_ops.start = ti_sci_dev_start;
 196         ti_sci_pd->pd.dev_ops.stop = ti_sci_dev_stop;
 197
 198         pm_genpd_init(&ti_sci_pd->pd, NULL, true);
 199
 200         ret = of_genpd_add_provider_simple(np, &ti_sci_pd->pd);
 201
 202         return ret;
 203 }
 204
 205 static struct platform_driver ti_sci_pm_domains_driver = {
 206         .probe = ti_sci_pm_domain_probe,
 207         .driver = {
 208                 .name = "ti_sci_pm_domains",
 209                 .of_match_table = ti_sci_pm_domain_matches,
 210         },
 211 };
 212 module_platform_driver(ti_sci_pm_domains_driver);
 213 MODULE_LICENSE("GPL v2");
 214 MODULE_DESCRIPTION("TI System Control Interface (SCI) Power Domain driver");
 215 MODULE_AUTHOR("Dave Gerlach");