drivers/staging/greybus/spi.c

   1 /*
   2  * SPI bridge PHY driver.
   3  *
   4  * Copyright 2014-2016 Google Inc.
   5  * Copyright 2014-2016 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include <linux/module.h>
  11
  12 #include "greybus.h"
  13 #include "gbphy.h"
  14 #include "spilib.h"
  15
  16 #ifndef SPI_CORE_SUPPORT_PM
  17 static int gbphy_spi_prepare_transfer_hardware(struct device *dev)
  18 {
  19         return gbphy_runtime_get_sync(to_gbphy_dev(dev));
  20 }
  21
  22 static void gbphy_spi_unprepare_transfer_hardware(struct device *dev)
  23 {
  24         gbphy_runtime_put_autosuspend(to_gbphy_dev(dev));
  25 }
  26
  27 static struct spilib_ops __spilib_ops = {
  28         .prepare_transfer_hardware = gbphy_spi_prepare_transfer_hardware,
  29         .unprepare_transfer_hardware = gbphy_spi_unprepare_transfer_hardware,
  30 };
  31
  32 static struct spilib_ops *spilib_ops = &__spilib_ops;
  33 #else
  34 static struct spilib_ops *spilib_ops = NULL;
  35 #endif
  36
  37 static int gb_spi_probe(struct gbphy_device *gbphy_dev,
  38                         const struct gbphy_device_id *id)
  39 {
  40         struct gb_connection *connection;
  41         int ret;
  42
  43         connection = gb_connection_create(gbphy_dev->bundle,
  44                                           le16_to_cpu(gbphy_dev->cport_desc->id),
  45                                           NULL);
  46         if (IS_ERR(connection))
  47                 return PTR_ERR(connection);
  48
  49         ret = gb_connection_enable(connection);
  50         if (ret)
  51                 goto exit_connection_destroy;
  52
  53         ret = gb_spilib_master_init(connection, &gbphy_dev->dev, spilib_ops);
  54         if (ret)
  55                 goto exit_connection_disable;
  56
  57         gb_gbphy_set_data(gbphy_dev, connection);
  58
  59         gbphy_runtime_put_autosuspend(gbphy_dev);
  60         return 0;
  61
  62 exit_connection_disable:
  63         gb_connection_disable(connection);
  64 exit_connection_destroy:
  65         gb_connection_destroy(connection);
  66
  67         return ret;
  68 }
  69
  70 static void gb_spi_remove(struct gbphy_device *gbphy_dev)
  71 {
  72         struct gb_connection *connection = gb_gbphy_get_data(gbphy_dev);
  73         int ret;
  74
  75         ret = gbphy_runtime_get_sync(gbphy_dev);
  76         if (ret)
  77                 gbphy_runtime_get_noresume(gbphy_dev);
  78
  79         gb_spilib_master_exit(connection);
  80         gb_connection_disable(connection);
  81         gb_connection_destroy(connection);
  82 }
  83
  84 static const struct gbphy_device_id gb_spi_id_table[] = {
  85         { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_SPI) },
  86         { },
  87 };
  88 MODULE_DEVICE_TABLE(gbphy, gb_spi_id_table);
  89
  90 static struct gbphy_driver spi_driver = {
  91         .name           = "spi",
  92         .probe          = gb_spi_probe,
  93         .remove         = gb_spi_remove,
  94         .id_table       = gb_spi_id_table,
  95 };
  96
  97 module_gbphy_driver(spi_driver);
  98 MODULE_LICENSE("GPL v2");