audio_codec: add common abstract layer

Common utilities:
- register shared memory (SHM)
- console channel

Common host commands:
- get_capabilities
- get_shm_addr
- set_shm_addr

BRANCH=none
BUG=b:122027734, b:123268236
TEST=1. define CONFIG_AUDIO_CODEC in board.h
2. make BOARD=kukui_scp -j

Change-Id: I90e3e112bf8fdffc13eb486e0c608c264650768b
Signed-off-by: Tzung-Bi Shih <tzungbi@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1616882
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Commit-Queue: Sean Abraham <seanabraham@chromium.org>

6 files changed, 268 insertions, 5 deletions

diff --git a/common/audio_codec.c b/common/audio_codec.c
new file mode 100644
index 0000000000..1dcc7e9b16
--- /dev/null
+++ b/common/audio_codec.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright 2019 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "audio_codec.h"
+#include "console.h"
+#include "host_command.h"
+
+#define CPRINTS(format, args...) cprints(CC_AUDIO_CODEC, format, ## args)
+
+static const uint32_t capabilities;
+
+static struct {
+	uint8_t cap;
+	uint8_t type;
+	uintptr_t *addr;
+	uint32_t len;
+} shms[EC_CODEC_SHM_ID_LAST];
+
+static int get_capabilities(struct host_cmd_handler_args *args)
+{
+	struct ec_response_ec_codec_get_capabilities *r = args->response;
+
+	r->capabilities = capabilities;
+
+	args->response_size = sizeof(*r);
+	return EC_RES_SUCCESS;
+}
+
+static int get_shm_addr(struct host_cmd_handler_args *args)
+{
+	const struct ec_param_ec_codec *p = args->params;
+	struct ec_response_ec_codec_get_shm_addr *r = args->response;
+	const uint8_t shm_id = p->get_shm_addr_param.shm_id;
+
+	if (shm_id >= EC_CODEC_SHM_ID_LAST)
+		return EC_RES_INVALID_PARAM;
+	if (!shms[shm_id].addr || !audio_codec_capable(shms[shm_id].cap))
+		return EC_RES_INVALID_PARAM;
+	if (!*shms[shm_id].addr &&
+	    shms[shm_id].type == EC_CODEC_SHM_TYPE_EC_RAM)
+		return EC_RES_ERROR;
+
+	r->len = shms[shm_id].len;
+	r->type = shms[shm_id].type;
+	r->phys_addr = *shms[shm_id].addr;
+
+	args->response_size = sizeof(*r);
+	return EC_RES_SUCCESS;
+}
+
+static int set_shm_addr(struct host_cmd_handler_args *args)
+{
+	const struct ec_param_ec_codec *p = args->params;
+	const uint8_t shm_id = p->set_shm_addr_param.shm_id;
+	uintptr_t ap_addr, ec_addr;
+
+	if (shm_id >= EC_CODEC_SHM_ID_LAST)
+		return EC_RES_INVALID_PARAM;
+	if (!shms[shm_id].addr || !audio_codec_capable(shms[shm_id].cap))
+		return EC_RES_INVALID_PARAM;
+	if (p->set_shm_addr_param.len < shms[shm_id].len)
+		return EC_RES_INVALID_PARAM;
+	if (*shms[shm_id].addr)
+		return EC_RES_BUSY;
+
+	ap_addr = (uintptr_t)p->set_shm_addr_param.phys_addr;
+	if (audio_codec_memmap_ap_to_ec(ap_addr, &ec_addr) != EC_SUCCESS)
+		return EC_RES_ERROR;
+	*shms[shm_id].addr = ec_addr;
+
+	args->response_size = 0;
+	return EC_RES_SUCCESS;
+}
+
+static int (*sub_cmds[])(struct host_cmd_handler_args *) = {
+	[EC_CODEC_GET_CAPABILITIES] = get_capabilities,
+	[EC_CODEC_GET_SHM_ADDR] = get_shm_addr,
+	[EC_CODEC_SET_SHM_ADDR] = set_shm_addr,
+};
+
+#ifdef DEBUG_AUDIO_CODEC
+static char *strcmd[] = {
+	[EC_CODEC_GET_CAPABILITIES] = "EC_CODEC_GET_CAPABILITIES",
+	[EC_CODEC_GET_SHM_ADDR] = "EC_CODEC_GET_SHM_ADDR",
+	[EC_CODEC_SET_SHM_ADDR] = "EC_CODEC_SET_SHM_ADDR",
+};
+BUILD_ASSERT(ARRAY_SIZE(sub_cmds) == ARRAY_SIZE(strcmd));
+#endif
+
+static int host_command(struct host_cmd_handler_args *args)
+{
+	const struct ec_param_ec_codec *p = args->params;
+
+#ifdef DEBUG_AUDIO_CODEC
+	CPRINTS("subcommand: %s", strcmd[p->cmd]);
+#endif
+
+	if (p->cmd < EC_CODEC_SUBCMD_COUNT)
+		return sub_cmds[p->cmd](args);
+
+	return EC_RES_INVALID_PARAM;
+}
+DECLARE_HOST_COMMAND(EC_CMD_EC_CODEC, host_command, EC_VER_MASK(0));
+
+/*
+ * Exported interfaces.
+ */
+int audio_codec_capable(uint8_t cap)
+{
+	return capabilities & BIT(cap);
+}
+
+int audio_codec_register_shm(uint8_t shm_id, uint8_t cap,
+		uintptr_t *addr, uint32_t len, uint8_t type)
+{
+	if (shm_id >= EC_CODEC_SHM_ID_LAST)
+		return EC_ERROR_INVAL;
+	if (cap >= EC_CODEC_CAP_LAST)
+		return EC_ERROR_INVAL;
+	if (shms[shm_id].addr || shms[shm_id].len)
+		return EC_ERROR_BUSY;
+
+	shms[shm_id].cap = cap;
+	shms[shm_id].addr = addr;
+	shms[shm_id].len = len;
+	shms[shm_id].type = type;
+
+	return EC_SUCCESS;
+}
+
+__attribute__((weak))
+int audio_codec_memmap_ap_to_ec(uintptr_t ap_addr, uintptr_t *ec_addr)
+{
+	return EC_ERROR_UNIMPLEMENTED;
+}
diff --git a/common/build.mk b/common/build.mk
index 02c08ac8ff..213db0a0fc 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -29,6 +29,7 @@ common-$(CONFIG_AES_GCM)+=aes-gcm.o
 common-$(CONFIG_CMD_ADC)+=adc.o
 common-$(HAS_TASK_ALS)+=als.o
 common-$(CONFIG_AP_HANG_DETECT)+=ap_hang_detect.o
+common-$(CONFIG_AUDIO_CODEC)+=audio_codec.o
 common-$(CONFIG_BACKLIGHT_LID)+=backlight_lid.o
 common-$(CONFIG_BASE32)+=base32.o
 common-$(CONFIG_DETACHABLE_BASE)+=base_state.o
diff --git a/include/audio_codec.h b/include/audio_codec.h
new file mode 100644
index 0000000000..ab1c65ae61
--- /dev/null
+++ b/include/audio_codec.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2019 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_AUDIO_CODEC_H
+#define __CROS_EC_AUDIO_CODEC_H
+
+#include "stdint.h"
+
+/*
+ * Common abstract layer
+ */
+
+/*
+ * Checks capability of audio codec.
+ *
+ * @cap is an integer from enum ec_codec_cap.  Note that it represents a
+ * bit field in a 32-bit integer.  The valid range is [0, 31].
+ *
+ * Returns:
+ *   1 if audio codec capabilities include cap passed as parameter.
+ *   0 if not capable.
+ */
+int audio_codec_capable(uint8_t cap);
+
+/*
+ * Registers shared memory (SHM).
+ *
+ * @shm_id is a SHM identifier from enum ec_codec_shm_id.
+ * @cap is an integer from enum ec_codec_cap.
+ * @addr is the address pointer to the SHM.
+ * @len is the maximum length of the SHM.
+ * @type is an integer from enum ec_codec_shm_type.
+ *
+ * Returns:
+ *   EC_SUCCESS if success.
+ *   EC_ERROR_UNKNOWN if internal errors.
+ *   EC_ERROR_INVAL if invalid shm_id.
+ *   EC_ERROR_INVAL if invalid cap.
+ *   EC_ERROR_BUSY if the shm_id has been registered.
+ */
+int audio_codec_register_shm(uint8_t shm_id, uint8_t cap,
+		uintptr_t *addr, uint32_t len, uint8_t type);
+
+/*
+ * Translates the physical address from AP to EC's memory space.  Required if
+ * wants to use AP SHM.
+ *
+ * @ap_addr is physical address from AP.
+ * @ec_addr is the translation destination.
+ *
+ * Returns:
+ *   EC_SUCCESS if success.
+ *   EC_ERROR_UNKNOWN if internal errors.
+ *   EC_ERROR_UNIMPLEMENTED if no concrete implementation.
+ */
+int audio_codec_memmap_ap_to_ec(uintptr_t ap_addr, uintptr_t *ec_addr);
+
+#endif
diff --git a/include/config.h b/include/config.h
index da88d31015..b09f26555b 100644
--- a/include/config.h
+++ b/include/config.h
@@ -337,9 +337,6 @@
 /* Support AP Warm reset Interrupt. */
 #undef CONFIG_AP_WARM_RESET_INTERRUPT
 
-/* Support audio codec for WoV and I2S normal recording. */
-#undef CONFIG_AUDIO_CODEC
-
 /*
  * Enable support for CPU caches behaving according to the ARMv7-M ISA.
  * (so far, only the Cortex-M7 has such caches)
@@ -353,6 +350,9 @@
  */
 #undef CONFIG_ASSEMBLY_MULA32
 
+/* Support audio codec. */
+#undef CONFIG_AUDIO_CODEC
+
 /* Allow proprietary communication protocols' extensions. */
 #undef CONFIG_EXTENSION_COMMAND
 
diff --git a/include/console_channel.inc b/include/console_channel.inc
index 0f931e88f7..21059fc64e 100644
--- a/include/console_channel.inc
+++ b/include/console_channel.inc
@@ -7,6 +7,9 @@
 
 CONSOLE_CHANNEL(CC_COMMAND,      "command")
 CONSOLE_CHANNEL(CC_ACCEL,        "accel")
+#ifdef CONFIG_AUDIO_CODEC
+CONSOLE_CHANNEL(CC_AUDIO_CODEC,  "audio_codec")
+#endif
 #ifdef CONFIG_BLUETOOTH_LE
 CONSOLE_CHANNEL(CC_BLUETOOTH_LE, "bluetooth_le")
 #ifdef CONFIG_BLUETOOTH_LL_DEBUG
diff --git a/include/ec_commands.h b/include/ec_commands.h
index 954d956e65..057c3411f4 100644
--- a/include/ec_commands.h
+++ b/include/ec_commands.h
@@ -4659,8 +4659,68 @@ enum mkbp_cec_event {
 
 /*****************************************************************************/
 
+/* Commands for audio codec. */
+#define EC_CMD_EC_CODEC 0x00BC
+
+enum ec_codec_subcmd {
+	EC_CODEC_GET_CAPABILITIES = 0x0,
+	EC_CODEC_GET_SHM_ADDR = 0x1,
+	EC_CODEC_SET_SHM_ADDR = 0x2,
+	EC_CODEC_SUBCMD_COUNT,
+};
+
+enum ec_codec_cap {
+	EC_CODEC_CAP_LAST = 32,
+};
+
+enum ec_codec_shm_id {
+	EC_CODEC_SHM_ID_LAST,
+};
+
+enum ec_codec_shm_type {
+	EC_CODEC_SHM_TYPE_EC_RAM = 0x0,
+	EC_CODEC_SHM_TYPE_SYSTEM_RAM = 0x1,
+};
+
+struct __ec_align1 ec_param_ec_codec_get_shm_addr {
+	uint8_t shm_id;
+	uint8_t reserved[3];
+};
+
+struct __ec_align4 ec_param_ec_codec_set_shm_addr {
+	uint64_t phys_addr;
+	uint32_t len;
+	uint8_t shm_id;
+	uint8_t reserved[3];
+};
+
+struct __ec_align4 ec_param_ec_codec {
+	uint8_t cmd; /* enum ec_codec_subcmd */
+	uint8_t reserved[3];
+
+	union {
+		struct ec_param_ec_codec_get_shm_addr
+				get_shm_addr_param;
+		struct ec_param_ec_codec_set_shm_addr
+				set_shm_addr_param;
+	};
+};
+
+struct __ec_align4 ec_response_ec_codec_get_capabilities {
+	uint32_t capabilities;
+};
+
+struct __ec_align4 ec_response_ec_codec_get_shm_addr {
+	uint64_t phys_addr;
+	uint32_t len;
+	uint8_t type;
+	uint8_t reserved[3];
+};
+
+/*****************************************************************************/
+
 /* Commands for DMIC on audio codec. */
-#define EC_CMD_EC_CODEC_DMIC 0x00BC
+#define EC_CMD_EC_CODEC_DMIC 0x00BD
 
 enum ec_codec_dmic_subcmd {
 	EC_CODEC_DMIC_SET_GAIN = 0x0,
@@ -4693,7 +4753,7 @@ struct __ec_align1 ec_response_ec_codec_dmic_get_gain {
 
 /* Commands for I2S RX on audio codec. */
 
-#define EC_CMD_EC_CODEC_I2S_RX 0x00BD
+#define EC_CMD_EC_CODEC_I2S_RX 0x00BE
 
 enum ec_codec_i2s_rx_subcmd {
 	EC_CODEC_I2S_RX_ENABLE = 0x0,