diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/bluetooth/btintel.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c index 7d5e4de64e3c..1ccbb5157515 100644 --- a/drivers/bluetooth/btintel.c +++ b/drivers/bluetooth/btintel.c @@ -12,6 +12,7 @@ #include <linux/acpi.h> #include <acpi/acpi_bus.h> #include <asm/unaligned.h> +#include <linux/efi.h> #include <net/bluetooth/bluetooth.h> #include <net/bluetooth/hci_core.h> @@ -26,6 +27,8 @@ #define ECDSA_OFFSET 644 #define ECDSA_HEADER_LEN 320 +#define BTINTEL_EFI_DSBR L"UefiCnvCommonDSBR" + enum { DSM_SET_WDISABLE2_DELAY = 1, DSM_SET_RESET_METHOD = 3, @@ -2616,6 +2619,120 @@ static u8 btintel_classify_pkt_type(struct hci_dev *hdev, struct sk_buff *skb) return hci_skb_pkt_type(skb); } +/* + * UefiCnvCommonDSBR UEFI variable provides information from the OEM platforms + * if they have replaced the BRI (Bluetooth Radio Interface) resistor to + * overcome the potential STEP errors on their designs. Based on the + * configauration, bluetooth firmware shall adjust the BRI response line drive + * strength. The below structure represents DSBR data. + * struct { + * u8 header; + * u32 dsbr; + * } __packed; + * + * header - defines revision number of the structure + * dsbr - defines drive strength BRI response + * bit0 + * 0 - instructs bluetooth firmware to use default values + * 1 - instructs bluetooth firmware to override default values + * bit3:1 + * Reserved + * bit7:4 + * DSBR override values (only if bit0 is set. Default value is 0xF + * bit31:7 + * Reserved + * Expected values for dsbr field: + * 1. 0xF1 - indicates that the resistor on board is 33 Ohm + * 2. 0x00 or 0xB1 - indicates that the resistor on board is 10 Ohm + * 3. Non existing UEFI variable or invalid (none of the above) - indicates + * that the resistor on board is 10 Ohm + * Even if uefi variable is not present, driver shall send 0xfc0a command to + * firmware to use default values. + * + */ +static int btintel_uefi_get_dsbr(u32 *dsbr_var) +{ + struct btintel_dsbr { + u8 header; + u32 dsbr; + } __packed data; + + efi_status_t status; + unsigned long data_size = 0; + efi_guid_t guid = EFI_GUID(0xe65d8884, 0xd4af, 0x4b20, 0x8d, 0x03, + 0x77, 0x2e, 0xcc, 0x3d, 0xa5, 0x31); + + if (!IS_ENABLED(CONFIG_EFI)) + return -EOPNOTSUPP; + + if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) + return -EOPNOTSUPP; + + status = efi.get_variable(BTINTEL_EFI_DSBR, &guid, NULL, &data_size, + NULL); + + if (status != EFI_BUFFER_TOO_SMALL || !data_size) + return -EIO; + + status = efi.get_variable(BTINTEL_EFI_DSBR, &guid, NULL, &data_size, + &data); + + if (status != EFI_SUCCESS) + return -ENXIO; + + *dsbr_var = data.dsbr; + return 0; +} + +static int btintel_set_dsbr(struct hci_dev *hdev, struct intel_version_tlv *ver) +{ + struct btintel_dsbr_cmd { + u8 enable; + u8 dsbr; + } __packed; + + struct btintel_dsbr_cmd cmd; + struct sk_buff *skb; + u8 status; + u32 dsbr; + bool apply_dsbr; + int err; + + /* DSBR command needs to be sent for BlazarI + B0 step product after + * downloading IML image. + */ + apply_dsbr = (ver->img_type == BTINTEL_IMG_IML && + ((ver->cnvi_top & 0xfff) == BTINTEL_CNVI_BLAZARI) && + INTEL_CNVX_TOP_STEP(ver->cnvi_top) == 0x01); + + if (!apply_dsbr) + return 0; + + dsbr = 0; + err = btintel_uefi_get_dsbr(&dsbr); + if (err < 0) + bt_dev_dbg(hdev, "Error reading efi: %ls (%d)", + BTINTEL_EFI_DSBR, err); + + cmd.enable = dsbr & BIT(0); + cmd.dsbr = dsbr >> 4 & 0xF; + + bt_dev_info(hdev, "dsbr: enable: 0x%2.2x value: 0x%2.2x", cmd.enable, + cmd.dsbr); + + skb = __hci_cmd_sync(hdev, 0xfc0a, sizeof(cmd), &cmd, HCI_CMD_TIMEOUT); + if (IS_ERR(skb)) + return -bt_to_errno(PTR_ERR(skb)); + + status = skb->data[0]; + kfree_skb(skb); + + if (status) + return -bt_to_errno(status); + + return 0; +} + int btintel_bootloader_setup_tlv(struct hci_dev *hdev, struct intel_version_tlv *ver) { @@ -2650,6 +2767,13 @@ int btintel_bootloader_setup_tlv(struct hci_dev *hdev, if (err) return err; + /* set drive strength of BRI response */ + err = btintel_set_dsbr(hdev, ver); + if (err) { + bt_dev_err(hdev, "Failed to send dsbr command (%d)", err); + return err; + } + /* If image type returned is BTINTEL_IMG_IML, then controller supports * intermediate loader image */ |