drivers/soundwire/intel_init.c

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