root/drivers/soundwire/intel_init.c

DEFINITIONS

1. sdw_intel_cleanup_pdev
2. sdw_intel_add_controller
3. sdw_intel_acpi_cb
4. sdw_intel_init
5. sdw_intel_exit

   1 // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
   2 // Copyright(c) 2015-17 Intel Corporation.
   3 
   4 /*
   5  * SDW Intel Init Routines
   6  *
   7  * Initializes and creates SDW devices based on ACPI and Hardware values
   8  */
   9 
  10 #include <linux/acpi.h>
  11 #include <linux/export.h>
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/soundwire/sdw_intel.h>
  15 #include "intel.h"
  16 
  17 #define SDW_LINK_TYPE           4 /* from Intel ACPI documentation */
  18 #define SDW_MAX_LINKS           4
  19 #define SDW_SHIM_LCAP           0x0
  20 #define SDW_SHIM_BASE           0x2C000
  21 #define SDW_ALH_BASE            0x2C800
  22 #define SDW_LINK_BASE           0x30000
  23 #define SDW_LINK_SIZE           0x10000
  24 
  25 static int link_mask;
  26 module_param_named(sdw_link_mask, link_mask, int, 0444);
  27 MODULE_PARM_DESC(sdw_link_mask, "Intel link mask (one bit per link)");
  28 
  29 struct sdw_link_data {
  30         struct sdw_intel_link_res res;
  31         struct platform_device *pdev;
  32 };
  33 
  34 struct sdw_intel_ctx {
  35         int count;
  36         struct sdw_link_data *links;
  37 };
  38 
  39 static int sdw_intel_cleanup_pdev(struct sdw_intel_ctx *ctx)
  40 {
  41         struct sdw_link_data *link = ctx->links;
  42         int i;
  43 
  44         if (!link)
  45                 return 0;
  46 
  47         for (i = 0; i < ctx->count; i++) {
  48                 if (link->pdev)
  49                         platform_device_unregister(link->pdev);
  50                 link++;
  51         }
  52 
  53         kfree(ctx->links);
  54         ctx->links = NULL;
  55 
  56         return 0;
  57 }
  58 
  59 static struct sdw_intel_ctx
  60 *sdw_intel_add_controller(struct sdw_intel_res *res)
  61 {
  62         struct platform_device_info pdevinfo;
  63         struct platform_device *pdev;
  64         struct sdw_link_data *link;
  65         struct sdw_intel_ctx *ctx;
  66         struct acpi_device *adev;
  67         int ret, i;
  68         u8 count;
  69         u32 caps;
  70 
  71         if (acpi_bus_get_device(res->handle, &adev))
  72                 return NULL;
  73 
  74         /* Found controller, find links supported */
  75         count = 0;
  76         ret = fwnode_property_read_u8_array(acpi_fwnode_handle(adev),
  77                                             "mipi-sdw-master-count", &count, 1);
  78 
  79         /* Don't fail on error, continue and use hw value */
  80         if (ret) {
  81                 dev_err(&adev->dev,
  82                         "Failed to read mipi-sdw-master-count: %d\n", ret);
  83                 count = SDW_MAX_LINKS;
  84         }
  85 
  86         /* Check SNDWLCAP.LCOUNT */
  87         caps = ioread32(res->mmio_base + SDW_SHIM_BASE + SDW_SHIM_LCAP);
  88         caps &= GENMASK(2, 0);
  89 
  90         /* Check HW supported vs property value and use min of two */
  91         count = min_t(u8, caps, count);
  92 
  93         /* Check count is within bounds */
  94         if (count > SDW_MAX_LINKS) {
  95                 dev_err(&adev->dev, "Link count %d exceeds max %d\n",
  96                         count, SDW_MAX_LINKS);
  97                 return NULL;
  98         } else if (!count) {
  99                 dev_warn(&adev->dev, "No SoundWire links detected\n");
 100                 return NULL;
 101         }
 102 
 103         dev_dbg(&adev->dev, "Creating %d SDW Link devices\n", count);
 104 
 105         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
 106         if (!ctx)
 107                 return NULL;
 108 
 109         ctx->count = count;
 110         ctx->links = kcalloc(ctx->count, sizeof(*ctx->links), GFP_KERNEL);
 111         if (!ctx->links)
 112                 goto link_err;
 113 
 114         link = ctx->links;
 115 
 116         /* Create SDW Master devices */
 117         for (i = 0; i < count; i++) {
 118                 if (link_mask && !(link_mask & BIT(i))) {
 119                         dev_dbg(&adev->dev,
 120                                 "Link %d masked, will not be enabled\n", i);
 121                         link++;
 122                         continue;
 123                 }
 124 
 125                 link->res.irq = res->irq;
 126                 link->res.registers = res->mmio_base + SDW_LINK_BASE
 127                                         + (SDW_LINK_SIZE * i);
 128                 link->res.shim = res->mmio_base + SDW_SHIM_BASE;
 129                 link->res.alh = res->mmio_base + SDW_ALH_BASE;
 130 
 131                 link->res.ops = res->ops;
 132                 link->res.arg = res->arg;
 133 
 134                 memset(&pdevinfo, 0, sizeof(pdevinfo));
 135 
 136                 pdevinfo.parent = res->parent;
 137                 pdevinfo.name = "int-sdw";
 138                 pdevinfo.id = i;
 139                 pdevinfo.fwnode = acpi_fwnode_handle(adev);
 140                 pdevinfo.data = &link->res;
 141                 pdevinfo.size_data = sizeof(link->res);
 142 
 143                 pdev = platform_device_register_full(&pdevinfo);
 144                 if (IS_ERR(pdev)) {
 145                         dev_err(&adev->dev,
 146                                 "platform device creation failed: %ld\n",
 147                                 PTR_ERR(pdev));
 148                         goto pdev_err;
 149                 }
 150 
 151                 link->pdev = pdev;
 152                 link++;
 153         }
 154 
 155         return ctx;
 156 
 157 pdev_err:
 158         sdw_intel_cleanup_pdev(ctx);
 159 link_err:
 160         kfree(ctx);
 161         return NULL;
 162 }
 163 
 164 static acpi_status sdw_intel_acpi_cb(acpi_handle handle, u32 level,
 165                                      void *cdata, void **return_value)
 166 {
 167         struct sdw_intel_res *res = cdata;
 168         struct acpi_device *adev;
 169         acpi_status status;
 170         u64 adr;
 171 
 172         status = acpi_evaluate_integer(handle, METHOD_NAME__ADR, NULL, &adr);
 173         if (ACPI_FAILURE(status))
 174                 return AE_OK; /* keep going */
 175 
 176         if (acpi_bus_get_device(handle, &adev)) {
 177                 pr_err("%s: Couldn't find ACPI handle\n", __func__);
 178                 return AE_NOT_FOUND;
 179         }
 180 
 181         res->handle = handle;
 182 
 183         /*
 184          * On some Intel platforms, multiple children of the HDAS
 185          * device can be found, but only one of them is the SoundWire
 186          * controller. The SNDW device is always exposed with
 187          * Name(_ADR, 0x40000000), with bits 31..28 representing the
 188          * SoundWire link so filter accordingly
 189          */
 190         if ((adr & GENMASK(31, 28)) >> 28 != SDW_LINK_TYPE)
 191                 return AE_OK; /* keep going */
 192 
 193         /* device found, stop namespace walk */
 194         return AE_CTRL_TERMINATE;
 195 }
 196 
 197 /**
 198  * sdw_intel_init() - SoundWire Intel init routine
 199  * @parent_handle: ACPI parent handle
 200  * @res: resource data
 201  *
 202  * This scans the namespace and creates SoundWire link controller devices
 203  * based on the info queried.
 204  */
 205 void *sdw_intel_init(acpi_handle *parent_handle, struct sdw_intel_res *res)
 206 {
 207         acpi_status status;
 208 
 209         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
 210                                      parent_handle, 1,
 211                                      sdw_intel_acpi_cb,
 212                                      NULL, res, NULL);
 213         if (ACPI_FAILURE(status))
 214                 return NULL;
 215 
 216         return sdw_intel_add_controller(res);
 217 }
 218 EXPORT_SYMBOL(sdw_intel_init);
 219 
 220 /**
 221  * sdw_intel_exit() - SoundWire Intel exit
 222  * @arg: callback context
 223  *
 224  * Delete the controller instances created and cleanup
 225  */
 226 void sdw_intel_exit(void *arg)
 227 {
 228         struct sdw_intel_ctx *ctx = arg;
 229 
 230         sdw_intel_cleanup_pdev(ctx);
 231         kfree(ctx);
 232 }
 233 EXPORT_SYMBOL(sdw_intel_exit);
 234 
 235 MODULE_LICENSE("Dual BSD/GPL");
 236 MODULE_DESCRIPTION("Intel Soundwire Init Library");