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 <loic.poulain@xxxxxxxxx>
---
drivers/bluetooth/Kconfig | 4 +
drivers/bluetooth/Makefile | 2 +
drivers/bluetooth/regmap-ibt.c | 276 +++++++++++++++++++++++++++++++++++++++++
drivers/bluetooth/regmap-ibt.h | 17 +++
4 files changed, 299 insertions(+)
create mode 100644 drivers/bluetooth/regmap-ibt.c
create mode 100644 drivers/bluetooth/regmap-ibt.h
diff --git a/drivers/bluetooth/Kconfig b/drivers/bluetooth/Kconfig
index 0bd88c9..c05e928 100644
--- a/drivers/bluetooth/Kconfig
+++ b/drivers/bluetooth/Kconfig
@@ -5,6 +5,10 @@ menu "Bluetooth device drivers"
config BT_INTEL
tristate
+config BT_REGMAP_INTEL
+ select REGMAP
+ tristate
+
config BT_BCM
tristate
select FW_LOADER
diff --git a/drivers/bluetooth/Makefile b/drivers/bluetooth/Makefile
index 07c9cf3..cd399a9 100644
--- a/drivers/bluetooth/Makefile
+++ b/drivers/bluetooth/Makefile
@@ -24,6 +24,8 @@ obj-$(CONFIG_BT_BCM) += btbcm.o
obj-$(CONFIG_BT_RTL) += btrtl.o
obj-$(CONFIG_BT_QCA) += btqca.o
+obj-$(CONFIG_BT_REGMAP_INTEL) += regmap-ibt.o
+
btmrvl-y := btmrvl_main.o
btmrvl-$(CONFIG_DEBUG_FS) += btmrvl_debugfs.o
diff --git a/drivers/bluetooth/regmap-ibt.c b/drivers/bluetooth/regmap-ibt.c
new file mode 100644
index 0000000..e3682f7
--- /dev/null
+++ b/drivers/bluetooth/regmap-ibt.c
@@ -0,0 +1,276 @@
+/*
+ * Register map access API - iBT support
+ *
+ * Copyright 2015 Intel Corporation
+ *
+ * Author: Loic Poulain <loic.poulain@xxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/regmap.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+
+#include <net/bluetooth/bluetooth.h>
+#include <net/bluetooth/hci_core.h>
+
+#include "regmap-ibt.h"
+
+#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;
+};
+
+/**
+ * HCI Command payload for register read/write
+ *
+ * @raddr: Register address (32bit only)
+ * @mode: Value access mode (8bit, 16bit, 32bit)
+ * @len: Data len to read/write
+ * @data: Data to write
+ */
+struct ibt_cp_reg_access {
+ __le32 addr;
+ __u8 mode;
+ __u8 len;
+ __u8 data[0];
+} __packed;
+
+/**
+ * HCI Command Complete Event payload for register read
+ *
+ * @status: cmd read status
+ * @addr: Register address (32bit only)
+ * @data: Register value
+ */
+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)) {
+ bt_dev_err(ctx->hdev, "regmap: Register (0x%x) read error (%ld)",
+ le32_to_cpu(cp.addr), PTR_ERR(skb));
+ return PTR_ERR(skb);
+ }
+
+ 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)) {
+ bt_dev_err(ctx->hdev, "regmap: Register (0x%x) write error (%ld)",
+ le32_to_cpu(cp->addr), PTR_ERR(skb));
+ err = PTR_ERR(skb);
+ 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,
+};
+
+static struct regmap *__regmap_init_ibt(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config,
+ bool devm)
+{
+ struct regmap_ibt_context *ctx;
+
+ if (!config)
+ return ERR_PTR(-EINVAL);
+
+ bt_dev_info(hdev, "regmap: Init %s-R%x-W%x region", config->name,
+ opcode_read, opcode_write);
+
+ if (config->reg_bits != 32) {
+ bt_dev_err(hdev, "regmap: Unsupported address size: %d",
+ config->reg_bits);
+ return ERR_PTR(-EINVAL);
+ }
+
+ 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;
+
+ if (devm)
+ return devm_regmap_init(&hdev->dev, ®map_ibt, ctx, config);
+ else
+ return regmap_init(&hdev->dev, ®map_ibt, ctx, config);
+}
+
+/**
+ * regmap_init_ibt(): Initialize register map
+ *
+ * @hdev: HCI Device that will be interacted with
+ * @config: Configuration for register map
+ * @opcode_read: HCI opcode command for register-read operation
+ * @opcode_write: HCI opcode command for register-write operation
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.
+ */
+struct regmap *regmap_init_ibt(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config)
+{
+ return __regmap_init_ibt(hdev, opcode_read, opcode_write, config,
+ false);
+}
+EXPORT_SYMBOL_GPL(regmap_init_ibt);
+
+/**
+ * devm_regmap_init_ibt(): Initialize register map
+ *
+ * @hdev: HCI Device that will be interacted with
+ * @config: Configuration for register map
+ * @opcode_read: HCI opcode command for register-read operation
+ * @opcode_write: HCI opcode command for register-write operation
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap. The regmap will be automatically freed by the
+ * device management code.
+ */
+struct regmap *devm_regmap_init_ibt(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config)
+{
+ return __regmap_init_ibt(hdev, opcode_read, opcode_write, config,
+ true);
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init_ibt);
+
+MODULE_LICENSE("GPL");
diff --git a/drivers/bluetooth/regmap-ibt.h b/drivers/bluetooth/regmap-ibt.h
new file mode 100644
index 0000000..afab382
--- /dev/null
+++ b/drivers/bluetooth/regmap-ibt.h
@@ -0,0 +1,17 @@
+/*
+ * Register map access API - iBT support
+ *
+ * Copyright 2015 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+struct regmap *regmap_init_ibt(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config);
+
+struct regmap *devm_regmap_init_ibt(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config);
--
1.9.1
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