From d06f107bcd828a6c3ecd4a7d449d5d0c0dba0326 Mon Sep 17 00:00:00 2001 From: Loic Poulain Date: Thu, 1 Oct 2015 18:16:21 +0200 Subject: [PATCH] Bluetooth: btintel: Add iBT register access over HCI support Add regmap ibt to support Intel Bluetooth silicon register access over HCI. Intel BT/FM combo chip allows to read/write some registers (e.g. FM registers) via its HCI interface. Read/Write operations are performed via a HCI transaction composed of a HCI command (host->controller) followed by a HCI command complete event (controller->host). Read/Write Command opcodes can be specified to the regmap init function. We define data formats which are intel/vendor specific. Register Read/Write HCI command payload (Host): Field: | REG ADDR | MODE | DATA_LEN | DATA... | size: | 32b | 8b | 8b | 8b* | Register Read HCI command complete event payload (Controller): Field: | CMD STATUS | REG ADDR | DATA... | size: | 8b | 32b | 8b* | Register Write HCI command complete event payload (Controller): Field: | CMD_STATUS | size: | 8b | Since this payload is HCI encapsulated, Little Endian byte order is used. Write/Read Example: If we write 0x0000002a at address 0x00008c04, with opcode_write 0xfc5d, The resulting transaction is (btmon trace): < HCI Command (0x3f|0x005d) plen 10 [hci0] 04 8c 00 00 02 04 2a 00 00 00 > HCI Event (0x0e) plen 4 Unknown (0x3f|0x005d) ncmd 1 00 Then, if we read the same register with opcode_read 0xfc5e: < HCI Command (0x3f|0x005e) plen 6 [hci0] 04 8c 00 00 02 04 > HCI Event (0x0e) plen 12 [hci0] Unknown (0x3f|0x005e) ncmd 1 00 04 8c 00 00 2a 00 00 00 Signed-off-by: Loic Poulain Signed-off-by: Marcel Holtmann --- drivers/bluetooth/Kconfig | 1 + drivers/bluetooth/btintel.c | 196 ++++++++++++++++++++++++++++++++++++ drivers/bluetooth/btintel.h | 9 ++ 3 files changed, 206 insertions(+) diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig index 3d480d8c6111..62999546a301 100644 --- a/drivers/bluetooth/Kconfig +++ b/drivers/bluetooth/Kconfig @@ -4,6 +4,7 @@ menu "Bluetooth device drivers" config BT_INTEL tristate + select REGMAP config BT_BCM tristate diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c index 9e18988375eb..7047fe6a6a2b 100644 --- a/drivers/bluetooth/btintel.c +++ b/drivers/bluetooth/btintel.c @@ -23,6 +23,7 @@ #include #include +#include #include #include @@ -215,6 +216,201 @@ int btintel_load_ddc_config(struct hci_dev *hdev, const char *ddc_name) } EXPORT_SYMBOL_GPL(btintel_load_ddc_config); +/* ------- REGMAP IBT SUPPORT ------- */ + +#define IBT_REG_MODE_8BIT 0x00 +#define IBT_REG_MODE_16BIT 0x01 +#define IBT_REG_MODE_32BIT 0x02 + +struct regmap_ibt_context { + struct hci_dev *hdev; + __u16 op_write; + __u16 op_read; +}; + +struct ibt_cp_reg_access { + __le32 addr; + __u8 mode; + __u8 len; + __u8 data[0]; +} __packed; + +struct ibt_rp_reg_access { + __u8 status; + __le32 addr; + __u8 data[0]; +} __packed; + +static int regmap_ibt_read(void *context, const void *addr, size_t reg_size, + void *val, size_t val_size) +{ + struct regmap_ibt_context *ctx = context; + struct ibt_cp_reg_access cp; + struct ibt_rp_reg_access *rp; + struct sk_buff *skb; + int err = 0; + + if (reg_size != sizeof(__le32)) + return -EINVAL; + + switch (val_size) { + case 1: + cp.mode = IBT_REG_MODE_8BIT; + break; + case 2: + cp.mode = IBT_REG_MODE_16BIT; + break; + case 4: + cp.mode = IBT_REG_MODE_32BIT; + break; + default: + return -EINVAL; + } + + /* regmap provides a little-endian formatted addr */ + cp.addr = *(__le32 *)addr; + cp.len = val_size; + + bt_dev_dbg(ctx->hdev, "Register (0x%x) read", le32_to_cpu(cp.addr)); + + skb = hci_cmd_sync(ctx->hdev, ctx->op_read, sizeof(cp), &cp, + HCI_CMD_TIMEOUT); + if (IS_ERR(skb)) { + err = PTR_ERR(skb); + bt_dev_err(ctx->hdev, "regmap: Register (0x%x) read error (%d)", + le32_to_cpu(cp.addr), err); + return err; + } + + if (skb->len != sizeof(*rp) + val_size) { + bt_dev_err(ctx->hdev, "regmap: Register (0x%x) read error, bad len", + le32_to_cpu(cp.addr)); + err = -EINVAL; + goto done; + } + + rp = (struct ibt_rp_reg_access *)skb->data; + + if (rp->addr != cp.addr) { + bt_dev_err(ctx->hdev, "regmap: Register (0x%x) read error, bad addr", + le32_to_cpu(rp->addr)); + err = -EINVAL; + goto done; + } + + memcpy(val, rp->data, val_size); + +done: + kfree_skb(skb); + return err; +} + +static int regmap_ibt_gather_write(void *context, + const void *addr, size_t reg_size, + const void *val, size_t val_size) +{ + struct regmap_ibt_context *ctx = context; + struct ibt_cp_reg_access *cp; + struct sk_buff *skb; + int plen = sizeof(*cp) + val_size; + u8 mode; + int err = 0; + + if (reg_size != sizeof(__le32)) + return -EINVAL; + + switch (val_size) { + case 1: + mode = IBT_REG_MODE_8BIT; + break; + case 2: + mode = IBT_REG_MODE_16BIT; + break; + case 4: + mode = IBT_REG_MODE_32BIT; + break; + default: + return -EINVAL; + } + + cp = kmalloc(plen, GFP_KERNEL); + if (!cp) + return -ENOMEM; + + /* regmap provides a little-endian formatted addr/value */ + cp->addr = *(__le32 *)addr; + cp->mode = mode; + cp->len = val_size; + memcpy(&cp->data, val, val_size); + + bt_dev_dbg(ctx->hdev, "Register (0x%x) write", le32_to_cpu(cp->addr)); + + skb = hci_cmd_sync(ctx->hdev, ctx->op_write, plen, cp, HCI_CMD_TIMEOUT); + if (IS_ERR(skb)) { + err = PTR_ERR(skb); + bt_dev_err(ctx->hdev, "regmap: Register (0x%x) write error (%d)", + le32_to_cpu(cp->addr), err); + goto done; + } + kfree_skb(skb); + +done: + kfree(cp); + return err; +} + +static int regmap_ibt_write(void *context, const void *data, size_t count) +{ + /* data contains register+value, since we only support 32bit addr, + * minimum data size is 4 bytes. + */ + if (WARN_ONCE(count < 4, "Invalid register access")) + return -EINVAL; + + return regmap_ibt_gather_write(context, data, 4, data + 4, count - 4); +} + +static void regmap_ibt_free_context(void *context) +{ + kfree(context); +} + +static struct regmap_bus regmap_ibt = { + .read = regmap_ibt_read, + .write = regmap_ibt_write, + .gather_write = regmap_ibt_gather_write, + .free_context = regmap_ibt_free_context, + .reg_format_endian_default = REGMAP_ENDIAN_LITTLE, + .val_format_endian_default = REGMAP_ENDIAN_LITTLE, +}; + +/* Config is the same for all register regions */ +static const struct regmap_config regmap_ibt_cfg = { + .name = "btintel_regmap", + .reg_bits = 32, + .val_bits = 32, +}; + +struct regmap *btintel_regmap_init(struct hci_dev *hdev, u16 opcode_read, + u16 opcode_write) +{ + struct regmap_ibt_context *ctx; + + bt_dev_info(hdev, "regmap: Init R%x-W%x region", opcode_read, + opcode_write); + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); + if (!ctx) + return ERR_PTR(-ENOMEM); + + ctx->op_read = opcode_read; + ctx->op_write = opcode_write; + ctx->hdev = hdev; + + return regmap_init(&hdev->dev, ®map_ibt, ctx, ®map_ibt_cfg); +} +EXPORT_SYMBOL_GPL(btintel_regmap_init); + MODULE_AUTHOR("Marcel Holtmann "); MODULE_DESCRIPTION("Bluetooth support for Intel devices ver " VERSION); MODULE_VERSION(VERSION); diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h index 52deaf2817cf..f0655c476fd2 100644 --- a/drivers/bluetooth/btintel.h +++ b/drivers/bluetooth/btintel.h @@ -80,6 +80,9 @@ int btintel_secure_send(struct hci_dev *hdev, u8 fragment_type, u32 plen, const void *param); int btintel_load_ddc_config(struct hci_dev *hdev, const char *ddc_name); +struct regmap *btintel_regmap_init(struct hci_dev *hdev, u16 opcode_read, + u16 opcode_write); + #else static inline int btintel_check_bdaddr(struct hci_dev *hdev) @@ -113,4 +116,10 @@ static inline int btintel_load_ddc_config(struct hci_dev *hdev, return -EOPNOTSUPP; } +static inline struct regmap *btintel_regmap_init(struct hci_dev *hdev, + u16 opcode_read, + u16 opcode_write) +{ + return ERR_PTR(-EINVAL); +} #endif -- 2.20.1