Add HCI support to the regmap API.
Some HCI/BT devices provide register access via their HCI interface.
(e.g. FM registers access for Intel BT/FM combo chip)
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 vendor specific. However, regmap-hci
can be extended with any other implementation.
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.
Example:
If we want to write 0x32001122 in the register 0x00001142,
with opcode_write 0xfc58, the resulting HCI transaction will be:
________ ___________ __ __ ___________
> 58 fc 0a 42 11 00 00 02 04 22 11 00 32
CMD HDR REG ADDR MD SZ DATA
______________ __
< 0E 04 01 58 fc 00
CC EVT HDR ST
If we want to read the 32bit value stored in same register with
opcode_read 0xfc59:
________ ___________ __ __
> 59 fc 06 42 11 00 00 02 04
CMD HDR REG ADDR MD SZ
______________ __ ___________ ___________
< 0E 0c 01 59 fc 00 04 8c 00 00 22 11 00 32
CC EVT HDR ST REG ADDR DATA
Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxx>
---
drivers/base/regmap/Kconfig | 6 +-
drivers/base/regmap/Makefile | 1 +
drivers/base/regmap/regmap-hci.c | 282 +++++++++++++++++++++++++++++++++++++++
include/linux/regmap.h | 7 +
4 files changed, 295 insertions(+), 1 deletion(-)
create mode 100644 drivers/base/regmap/regmap-hci.c
diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index db9d00c3..b692b96 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -3,7 +3,7 @@
# subsystems should select the appropriate symbols.
config REGMAP
- default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ)
+ default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ || REGMAP_HCI)
select LZO_COMPRESS
select LZO_DECOMPRESS
select IRQ_DOMAIN if REGMAP_IRQ
@@ -29,3 +29,7 @@ config REGMAP_MMIO
config REGMAP_IRQ
bool
+
+config REGMAP_HCI
+ tristate
+ depends on BT
\ No newline at end of file
diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index 609e4c8..8cf31ea 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o
obj-$(CONFIG_REGMAP_SPMI) += regmap-spmi.o
obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o
obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o
+obj-$(CONFIG_REGMAP_HCI) += regmap-hci.o
diff --git a/drivers/base/regmap/regmap-hci.c b/drivers/base/regmap/regmap-hci.c
new file mode 100644
index 0000000..bcb91a8
--- /dev/null
+++ b/drivers/base/regmap/regmap-hci.c
@@ -0,0 +1,282 @@
+/*
+ * Register map access API - HCI 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 "internal.h"
+
+#define DEFAULT_OP_WRITE 0xfc58
+#define DEFAULT_OP_READ 0xfc59
+
+#define HCI_REG_MODE_8BIT 0x00
+#define HCI_REG_MODE_16BIT 0x01
+#define HCI_REG_MODE_32BIT 0x02
+
+struct regmap_hci_context {
+ struct hci_dev *hdev;
+ __u16 op_write;
+ __u16 op_read;
+};
+
+/**
+ * HCI Command payload for register read/write
+ *
+ * @reg: Register address (32bit only)
+ * @mode: Value access mode (8bit, 16bit, 32bit)
+ * @data_len: data len to read/write
+ * @data: data to write
+ */
+struct hci_command_reg_hdr {
+ __le32 reg;
+ __u8 mode;
+ __u8 data_len;
+ __u8 data[0];
+} __packed;
+
+/**
+ * HCI Command Complete Event payload for register read
+ *
+ * @reg: cmd read status
+ * @mode: Register address (32bit only)
+ * @data: Register value
+ */
+struct hci_cc_reg_hdr {
+ __u8 status;
+ __le32 reg;
+ __u8 data[0];
+} __packed;
+
+static int regmap_hci_read(void *context, const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct regmap_hci_context *ctx = context;
+ struct hci_dev *hdev = ctx->hdev;
+ struct sk_buff *skb;
+ struct hci_command_reg_hdr hdr;
+ struct hci_cc_reg_hdr *cc;
+
+ if (reg_size != sizeof(__le32))
+ return -EINVAL;
+
+ switch (val_size) {
+ case 1:
+ hdr.mode = HCI_REG_MODE_8BIT;
+ break;
+ case 2:
+ hdr.mode = HCI_REG_MODE_16BIT;
+ break;
+ case 4:
+ hdr.mode = HCI_REG_MODE_32BIT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ hdr.reg = *(__le32 *)reg;
+ hdr.data_len = val_size;
+
+ bt_dev_dbg(hdev, "regmap: Read register 0x%x", hdr.reg);
+
+ skb = __hci_cmd_sync(hdev, ctx->op_read, sizeof(hdr), &hdr,
+ HCI_CMD_TIMEOUT);
+ if (IS_ERR(skb)) {
+ bt_dev_err(hdev, "regmap: Read error, command failure");
+ return PTR_ERR(skb);
+ }
+
+ if (skb->len != sizeof(*cc) + val_size) {
+ bt_dev_err(hdev, "regmap: Read error, unexpected pkt len");
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ cc = (struct hci_cc_reg_hdr *)skb->data;
+
+ if (cc->reg != hdr.reg) {
+ bt_dev_err(hdev, "regmap: Read error, Invalid register 0x%x",
+ le32_to_cpu(cc->reg));
+ kfree_skb(skb);
+ return -EINVAL;
+ }
+
+ memcpy(val, cc->data, val_size);
+
+ kfree_skb(skb);
+
+ return 0;
+}
+
+static int regmap_hci_gather_write(void *context,
+ const void *reg, size_t reg_size,
+ const void *val, size_t val_size)
+{
+ struct regmap_hci_context *ctx = context;
+ struct hci_dev *hdev = ctx->hdev;
+ struct sk_buff *skb;
+ struct hci_command_reg_hdr *hdr;
+ int plen = sizeof(*hdr) + val_size;
+ u8 mode;
+
+ if (reg_size != sizeof(__le32))
+ return -EINVAL;
+
+ switch (val_size) {
+ case 1:
+ mode = HCI_REG_MODE_8BIT;
+ break;
+ case 2:
+ mode = HCI_REG_MODE_16BIT;
+ break;
+ case 4:
+ mode = HCI_REG_MODE_32BIT;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ hdr = kmalloc(plen, GFP_KERNEL);
+ if (!hdr)
+ return -ENOMEM;
+
+ hdr->reg = *(__le32 *)reg;
+ hdr->mode = mode;
+ hdr->data_len = val_size;
+ memcpy(&hdr->data, val, val_size);
+
+ bt_dev_dbg(hdev, "regmap: Write register 0x%x", hdr->reg);
+
+ skb = __hci_cmd_sync(hdev, ctx->op_write, plen, hdr, HCI_CMD_TIMEOUT);
+ if (IS_ERR(skb)) {
+ bt_dev_err(hdev, "regmap: Write error, command failure");
+ kfree(hdr);
+ return PTR_ERR(skb);
+ }
+ kfree_skb(skb);
+
+ kfree(hdr);
+
+ return 0;
+}
+
+static int regmap_hci_write(void *context, const void *data, size_t count)
+{
+ BUG_ON(count < 4);
+ return regmap_hci_gather_write(context, data, 4, data + 4, count - 4);
+}
+
+void regmap_hci_free_context(void *context)
+{
+ kfree(context);
+}
+
+static struct regmap_bus regmap_hci_default = {
+ .read = regmap_hci_read,
+ .write = regmap_hci_write,
+ .gather_write = regmap_hci_gather_write,
+ .free_context = regmap_hci_free_context,
+ .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
+ .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
+};
+
+/**
+ * regmap_init_hci(): Initialise 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.
+ */
+static struct regmap *__regmap_init_hci(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config,
+ bool devm)
+{
+ struct regmap_hci_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 ? opcode_read : DEFAULT_OP_READ;
+ ctx->op_write = opcode_write ? opcode_write : DEFAULT_OP_WRITE;
+ ctx->hdev = hdev;
+
+ if (devm)
+ return devm_regmap_init(&hdev->dev, ®map_hci_default, ctx,
+ config);
+ else
+ return regmap_init(&hdev->dev, ®map_hci_default, ctx,
+ config);
+}
+
+/**
+ * regmap_init_hci(): Initialise 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_hci(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config)
+{
+ return __regmap_init_hci(hdev, opcode_read, opcode_write, config,
+ false);
+}
+EXPORT_SYMBOL_GPL(regmap_init_hci);
+
+/**
+ * devm_regmap_init_hci(): Initialise 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_hci(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config)
+{
+ return __regmap_init_hci(hdev, opcode_read, opcode_write, config,
+ true);
+}
+EXPORT_SYMBOL_GPL(devm_regmap_init_hci);
+
+MODULE_LICENSE("GPL");
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 59c55ea..8a2823b 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -28,6 +28,7 @@ struct regmap;
struct regmap_range_cfg;
struct regmap_field;
struct snd_ac97;
+struct hci_dev;
/* An enum of all the supported cache types */
enum regcache_type {
@@ -343,6 +344,9 @@ struct regmap *regmap_init_mmio_clk(struct device *dev, const char *clk_id,
const struct regmap_config *config);
struct regmap *regmap_init_ac97(struct snd_ac97 *ac97,
const struct regmap_config *config);
+struct regmap *regmap_init_hci(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config);
struct regmap *devm_regmap_init(struct device *dev,
const struct regmap_bus *bus,
@@ -361,6 +365,9 @@ struct regmap *devm_regmap_init_mmio_clk(struct device *dev, const char *clk_id,
const struct regmap_config *config);
struct regmap *devm_regmap_init_ac97(struct snd_ac97 *ac97,
const struct regmap_config *config);
+struct regmap *devm_regmap_init_hci(struct hci_dev *hdev,
+ u16 opcode_read, u16 opcode_write,
+ const struct regmap_config *config);
bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);
--
1.9.1
--
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