drivers/soundwire/master.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 // Copyright(c) 2019-2020 Intel Corporation.
   3
   4 #include <linux/device.h>
   5 #include <linux/acpi.h>
   6 #include <linux/pm_runtime.h>
   7 #include <linux/soundwire/sdw.h>
   8 #include <linux/soundwire/sdw_type.h>
   9 #include "bus.h"
  10
  11 /*
  12  * The 3s value for autosuspend will only be used if there are no
  13  * devices physically attached on a bus segment. In practice enabling
  14  * the bus operation will result in children devices become active and
  15  * the master device will only suspend when all its children are no
  16  * longer active.
  17  */
  18 #define SDW_MASTER_SUSPEND_DELAY_MS 3000
  19
  20 /*
  21  * The sysfs for properties reflects the MIPI description as given
  22  * in the MIPI DisCo spec
  23  *
  24  * Base file is:
  25  *      sdw-master-N
  26  *      |---- revision
  27  *      |---- clk_stop_modes
  28  *      |---- max_clk_freq
  29  *      |---- clk_freq
  30  *      |---- clk_gears
  31  *      |---- default_row
  32  *      |---- default_col
  33  *      |---- dynamic_shape
  34  *      |---- err_threshold
  35  */
  36
  37 #define sdw_master_attr(field, format_string)                           \
  38 static ssize_t field##_show(struct device *dev,                         \
  39                             struct device_attribute *attr,              \
  40                             char *buf)                                  \
  41 {                                                                       \
  42         struct sdw_master_device *md = dev_to_sdw_master_device(dev);   \
  43         return sprintf(buf, format_string, md->bus->prop.field);        \
  44 }                                                                       \
  45 static DEVICE_ATTR_RO(field)
  46
  47 sdw_master_attr(revision, "0x%x\n");
  48 sdw_master_attr(clk_stop_modes, "0x%x\n");
  49 sdw_master_attr(max_clk_freq, "%d\n");
  50 sdw_master_attr(default_row, "%d\n");
  51 sdw_master_attr(default_col, "%d\n");
  52 sdw_master_attr(default_frame_rate, "%d\n");
  53 sdw_master_attr(dynamic_frame, "%d\n");
  54 sdw_master_attr(err_threshold, "%d\n");
  55
  56 static ssize_t clock_frequencies_show(struct device *dev,
  57                                       struct device_attribute *attr, char *buf)
  58 {
  59         struct sdw_master_device *md = dev_to_sdw_master_device(dev);
  60         ssize_t size = 0;
  61         int i;
  62
  63         for (i = 0; i < md->bus->prop.num_clk_freq; i++)
  64                 size += sprintf(buf + size, "%8d ",
  65                                 md->bus->prop.clk_freq[i]);
  66         size += sprintf(buf + size, "\n");
  67
  68         return size;
  69 }
  70 static DEVICE_ATTR_RO(clock_frequencies);
  71
  72 static ssize_t clock_gears_show(struct device *dev,
  73                                 struct device_attribute *attr, char *buf)
  74 {
  75         struct sdw_master_device *md = dev_to_sdw_master_device(dev);
  76         ssize_t size = 0;
  77         int i;
  78
  79         for (i = 0; i < md->bus->prop.num_clk_gears; i++)
  80                 size += sprintf(buf + size, "%8d ",
  81                                 md->bus->prop.clk_gears[i]);
  82         size += sprintf(buf + size, "\n");
  83
  84         return size;
  85 }
  86 static DEVICE_ATTR_RO(clock_gears);
  87
  88 static struct attribute *master_node_attrs[] = {
  89         &dev_attr_revision.attr,
  90         &dev_attr_clk_stop_modes.attr,
  91         &dev_attr_max_clk_freq.attr,
  92         &dev_attr_default_row.attr,
  93         &dev_attr_default_col.attr,
  94         &dev_attr_default_frame_rate.attr,
  95         &dev_attr_dynamic_frame.attr,
  96         &dev_attr_err_threshold.attr,
  97         &dev_attr_clock_frequencies.attr,
  98         &dev_attr_clock_gears.attr,
  99         NULL,
 100 };
 101 ATTRIBUTE_GROUPS(master_node);
 102
 103 static void sdw_master_device_release(struct device *dev)
 104 {
 105         struct sdw_master_device *md = dev_to_sdw_master_device(dev);
 106
 107         kfree(md);
 108 }
 109
 110 static const struct dev_pm_ops master_dev_pm = {
 111         SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend,
 112                            pm_generic_runtime_resume, NULL)
 113 };
 114
 115 struct device_type sdw_master_type = {
 116         .name =         "soundwire_master",
 117         .release =      sdw_master_device_release,
 118         .pm = &master_dev_pm,
 119 };
 120
 121 /**
 122  * sdw_master_device_add() - create a Linux Master Device representation.
 123  * @bus: SDW bus instance
 124  * @parent: parent device
 125  * @fwnode: firmware node handle
 126  */
 127 int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,
 128                           struct fwnode_handle *fwnode)
 129 {
 130         struct sdw_master_device *md;
 131         int ret;
 132
 133         if (!parent)
 134                 return -EINVAL;
 135
 136         md = kzalloc(sizeof(*md), GFP_KERNEL);
 137         if (!md)
 138                 return -ENOMEM;
 139
 140         md->dev.bus = &sdw_bus_type;
 141         md->dev.type = &sdw_master_type;
 142         md->dev.parent = parent;
 143         md->dev.groups = master_node_groups;
 144         md->dev.of_node = parent->of_node;
 145         md->dev.fwnode = fwnode;
 146         md->dev.dma_mask = parent->dma_mask;
 147
 148         dev_set_name(&md->dev, "sdw-master-%d", bus->id);
 149
 150         ret = device_register(&md->dev);
 151         if (ret) {
 152                 dev_err(parent, "Failed to add master: ret %d\n", ret);
 153                 /*
 154                  * On err, don't free but drop ref as this will be freed
 155                  * when release method is invoked.
 156                  */
 157                 put_device(&md->dev);
 158                 goto device_register_err;
 159         }
 160
 161         /* add shortcuts to improve code readability/compactness */
 162         md->bus = bus;
 163         bus->dev = &md->dev;
 164         bus->md = md;
 165
 166         pm_runtime_set_autosuspend_delay(&bus->md->dev, SDW_MASTER_SUSPEND_DELAY_MS);
 167         pm_runtime_use_autosuspend(&bus->md->dev);
 168         pm_runtime_mark_last_busy(&bus->md->dev);
 169         pm_runtime_set_active(&bus->md->dev);
 170         pm_runtime_enable(&bus->md->dev);
 171         pm_runtime_idle(&bus->md->dev);
 172 device_register_err:
 173         return ret;
 174 }
 175
 176 /**
 177  * sdw_master_device_del() - delete a Linux Master Device representation.
 178  * @bus: bus handle
 179  *
 180  * This function is the dual of sdw_master_device_add()
 181  */
 182 int sdw_master_device_del(struct sdw_bus *bus)
 183 {
 184         pm_runtime_disable(&bus->md->dev);
 185         device_unregister(bus->dev);
 186
 187         return 0;
 188 }