#include <linux/gpio.h>
#include <linux/platform_device.h>
-/*
- * Definition of buttons on the tablet. The ACPI index of each button
- * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
- * Platforms"
- */
-#define MAX_NBUTTONS 5
-
struct soc_button_info {
const char *name;
int acpi_index;
struct gpio_desc *desc;
int gpio;
- desc = gpiod_get_index(dev, KBUILD_MODNAME, acpi_index, GPIOD_ASIS);
+ desc = gpiod_get_index(dev, NULL, acpi_index, GPIOD_ASIS);
if (IS_ERR(desc))
return PTR_ERR(desc);
int gpio;
int error;
+ for (info = button_info; info->name; info++)
+ if (info->autorepeat == autorepeat)
+ n_buttons++;
+
gpio_keys_pdata = devm_kzalloc(&pdev->dev,
sizeof(*gpio_keys_pdata) +
- sizeof(*gpio_keys) * MAX_NBUTTONS,
+ sizeof(*gpio_keys) * n_buttons,
GFP_KERNEL);
if (!gpio_keys_pdata)
return ERR_PTR(-ENOMEM);
gpio_keys = (void *)(gpio_keys_pdata + 1);
+ n_buttons = 0;
for (info = button_info; info->name; info++) {
if (info->autorepeat != autorepeat)
return ERR_PTR(error);
}
+static int soc_button_get_acpi_object_int(const union acpi_object *obj)
+{
+ if (obj->type != ACPI_TYPE_INTEGER)
+ return -1;
+
+ return obj->integer.value;
+}
+
+/* Parse a single ACPI0011 _DSD button descriptor */
+static int soc_button_parse_btn_desc(struct device *dev,
+ const union acpi_object *desc,
+ int collection_uid,
+ struct soc_button_info *info)
+{
+ int upage, usage;
+
+ if (desc->type != ACPI_TYPE_PACKAGE ||
+ desc->package.count != 5 ||
+ /* First byte should be 1 (control) */
+ soc_button_get_acpi_object_int(&desc->package.elements[0]) != 1 ||
+ /* Third byte should be collection uid */
+ soc_button_get_acpi_object_int(&desc->package.elements[2]) !=
+ collection_uid) {
+ dev_err(dev, "Invalid ACPI Button Descriptor\n");
+ return -ENODEV;
+ }
+
+ info->event_type = EV_KEY;
+ info->acpi_index =
+ soc_button_get_acpi_object_int(&desc->package.elements[1]);
+ upage = soc_button_get_acpi_object_int(&desc->package.elements[3]);
+ usage = soc_button_get_acpi_object_int(&desc->package.elements[4]);
+
+ /*
+ * The UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e descriptors use HID
+ * usage page and usage codes, but otherwise the device is not HID
+ * compliant: it uses one irq per button instead of generating HID
+ * input reports and some buttons should generate wakeups where as
+ * others should not, so we cannot use the HID subsystem.
+ *
+ * Luckily all devices only use a few usage page + usage combinations,
+ * so we can simply check for the known combinations here.
+ */
+ if (upage == 0x01 && usage == 0x81) {
+ info->name = "power";
+ info->event_code = KEY_POWER;
+ info->wakeup = true;
+ } else if (upage == 0x07 && usage == 0xe3) {
+ info->name = "home";
+ info->event_code = KEY_LEFTMETA;
+ info->wakeup = true;
+ } else if (upage == 0x0c && usage == 0xe9) {
+ info->name = "volume_up";
+ info->event_code = KEY_VOLUMEUP;
+ info->autorepeat = true;
+ } else if (upage == 0x0c && usage == 0xea) {
+ info->name = "volume_down";
+ info->event_code = KEY_VOLUMEDOWN;
+ info->autorepeat = true;
+ } else {
+ dev_warn(dev, "Unknown button index %d upage %02x usage %02x, ignoring\n",
+ info->acpi_index, upage, usage);
+ info->name = "unknown";
+ info->event_code = KEY_RESERVED;
+ }
+
+ return 0;
+}
+
+/* ACPI0011 _DSD btns descriptors UUID: fa6bd625-9ce8-470d-a2c7-b3ca36c4282e */
+static const u8 btns_desc_uuid[16] = {
+ 0x25, 0xd6, 0x6b, 0xfa, 0xe8, 0x9c, 0x0d, 0x47,
+ 0xa2, 0xc7, 0xb3, 0xca, 0x36, 0xc4, 0x28, 0x2e
+};
+
+/* Parse ACPI0011 _DSD button descriptors */
+static struct soc_button_info *soc_button_get_button_info(struct device *dev)
+{
+ struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
+ const union acpi_object *desc, *el0, *uuid, *btns_desc = NULL;
+ struct soc_button_info *button_info;
+ acpi_status status;
+ int i, btn, collection_uid = -1;
+
+ status = acpi_evaluate_object_typed(ACPI_HANDLE(dev), "_DSD", NULL,
+ &buf, ACPI_TYPE_PACKAGE);
+ if (ACPI_FAILURE(status)) {
+ dev_err(dev, "ACPI _DSD object not found\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ /* Look for the Button Descriptors UUID */
+ desc = buf.pointer;
+ for (i = 0; (i + 1) < desc->package.count; i += 2) {
+ uuid = &desc->package.elements[i];
+
+ if (uuid->type != ACPI_TYPE_BUFFER ||
+ uuid->buffer.length != 16 ||
+ desc->package.elements[i + 1].type != ACPI_TYPE_PACKAGE) {
+ break;
+ }
+
+ if (memcmp(uuid->buffer.pointer, btns_desc_uuid, 16) == 0) {
+ btns_desc = &desc->package.elements[i + 1];
+ break;
+ }
+ }
+
+ if (!btns_desc) {
+ dev_err(dev, "ACPI Button Descriptors not found\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ /* The first package describes the collection */
+ el0 = &btns_desc->package.elements[0];
+ if (el0->type == ACPI_TYPE_PACKAGE &&
+ el0->package.count == 5 &&
+ /* First byte should be 0 (collection) */
+ soc_button_get_acpi_object_int(&el0->package.elements[0]) == 0 &&
+ /* Third byte should be 0 (top level collection) */
+ soc_button_get_acpi_object_int(&el0->package.elements[2]) == 0) {
+ collection_uid = soc_button_get_acpi_object_int(
+ &el0->package.elements[1]);
+ }
+ if (collection_uid == -1) {
+ dev_err(dev, "Invalid Button Collection Descriptor\n");
+ return ERR_PTR(-ENODEV);
+ }
+
+ /* There are package.count - 1 buttons + 1 terminating empty entry */
+ button_info = devm_kcalloc(dev, btns_desc->package.count,
+ sizeof(*button_info), GFP_KERNEL);
+ if (!button_info)
+ return ERR_PTR(-ENOMEM);
+
+ /* Parse the button descriptors */
+ for (i = 1, btn = 0; i < btns_desc->package.count; i++, btn++) {
+ if (soc_button_parse_btn_desc(dev,
+ &btns_desc->package.elements[i],
+ collection_uid,
+ &button_info[btn]))
+ return ERR_PTR(-ENODEV);
+ }
+
+ return button_info;
+}
+
static int soc_button_remove(struct platform_device *pdev)
{
struct soc_button_data *priv = platform_get_drvdata(pdev);
if (!id)
return -ENODEV;
- button_info = (struct soc_button_info *)id->driver_data;
+ if (!id->driver_data) {
+ button_info = soc_button_get_button_info(dev);
+ if (IS_ERR(button_info))
+ return PTR_ERR(button_info);
+ } else {
+ button_info = (struct soc_button_info *)id->driver_data;
+ }
error = gpiod_count(dev, NULL);
if (error < 0) {
if (!priv->children[0] && !priv->children[1])
return -ENODEV;
+ if (!id->driver_data)
+ devm_kfree(dev, button_info);
+
return 0;
}
+/*
+ * Definition of buttons on the tablet. The ACPI index of each button
+ * is defined in section 2.8.7.2 of "Windows ACPI Design Guide for SoC
+ * Platforms"
+ */
static struct soc_button_info soc_button_PNP0C40[] = {
{ "power", 0, EV_KEY, KEY_POWER, false, true },
{ "home", 1, EV_KEY, KEY_LEFTMETA, false, true },
static const struct acpi_device_id soc_button_acpi_match[] = {
{ "PNP0C40", (unsigned long)soc_button_PNP0C40 },
+ { "ACPI0011", 0 },
{ }
};
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