[PATCH v5 0/3] This patches provide ADSP IPC support for MT8195
Mediatek ADSP IPC is used to send notification or short message between processors with dsp.ยท
It will place the message to the share buffer and will access the ADSP mailbox registers to kick dsp.
Two mailboxes used to send notification or short message between processors with dsp
changes since v4: - use switch ... case in adsp_ipc_recv - add error handling path for chan_name pointer - refine some code to be concise
changes since v3: - reorder MTK_ADSP_IPC_MBOX config - remove some redundant code - remove lock in mtk-adsp-mailbox
changes since v2: - separate adsp_mailbox into two instances
changes since v1: - fix dt_binding_check error
Allen-KH Cheng (3): dt-bindings: mediatek: add adsp-mbox document firmware: mediatek: add adsp ipc protocol interface mailbox: mediatek: add support for adsp mailbox controller
.../bindings/mailbox/mtk,adsp-mbox.yaml | 52 +++++ drivers/firmware/Kconfig | 1 + drivers/firmware/Makefile | 1 + drivers/firmware/mediatek/Kconfig | 9 + drivers/firmware/mediatek/Makefile | 2 + drivers/firmware/mediatek/mtk-adsp-ipc.c | 138 ++++++++++++++ drivers/mailbox/Kconfig | 7 + drivers/mailbox/Makefile | 2 + drivers/mailbox/mtk-adsp-mailbox.c | 178 ++++++++++++++++++ .../linux/firmware/mediatek/mtk-adsp-ipc.h | 70 +++++++ 10 files changed, 460 insertions(+) create mode 100644 Documentation/devicetree/bindings/mailbox/mtk,adsp-mbox.yaml create mode 100644 drivers/firmware/mediatek/Kconfig create mode 100644 drivers/firmware/mediatek/Makefile create mode 100644 drivers/firmware/mediatek/mtk-adsp-ipc.c create mode 100644 drivers/mailbox/mtk-adsp-mailbox.c create mode 100644 include/linux/firmware/mediatek/mtk-adsp-ipc.h
From: Allen-KH Cheng Allen-KH.Cheng@mediatek.com
This patch adds document for mediatek adsp mbox
Signed-off-by: Allen-KH Cheng Allen-KH.Cheng@mediatek.com --- .../bindings/mailbox/mtk,adsp-mbox.yaml | 52 +++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 Documentation/devicetree/bindings/mailbox/mtk,adsp-mbox.yaml
diff --git a/Documentation/devicetree/bindings/mailbox/mtk,adsp-mbox.yaml b/Documentation/devicetree/bindings/mailbox/mtk,adsp-mbox.yaml new file mode 100644 index 000000000000..a0149566ae56 --- /dev/null +++ b/Documentation/devicetree/bindings/mailbox/mtk,adsp-mbox.yaml @@ -0,0 +1,52 @@ +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/mailbox/mtk,adsp-mbox.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Mediatek ADSP mailbox + +maintainers: + - Allen-KH Cheng Allen-KH.Cheng@mediatek.com + +description: | + The MTK ADSP mailbox Inter-Processor Communication (IPC) enables the SoC + to ommunicate with ADSP by passing messages through two mailbox channels. + The MTK ADSP mailbox IPC also provides the ability for one processor to + signal the other processor using interrupts. + +properties: + compatible: + items: + - const: mediatek,mt8195-adsp-mbox + + "#mbox-cells": + const: 0 + + reg: + description: + Physical address base for dsp mbox base registers. + + interrupts: + description: + adsp mbox interrupt + +required: + - compatible + - "#mbox-cells" + - reg + - interrupts + +additionalProperties: false + +examples: + - | + #include <dt-bindings/interrupt-controller/arm-gic.h> + #include <dt-bindings/interrupt-controller/irq.h> + + adsp_mailbox0:adsp_mailbox0@10816000 { + compatible = "mediatek,mt8195-adsp-mbox"; + #mbox-cells = <0>; + reg = <0x10816000 0x1000>; + interrupts = <GIC_SPI 702 IRQ_TYPE_LEVEL_HIGH 0>; + };
From: Allen-KH Cheng Allen-KH.Cheng@mediatek.com
Some of mediatek processors contain the Tensilica HiFix DSP for audio processing.
The communication between Host CPU and DSP firmware is taking place using a shared memory area for message passing.
ADSP IPC protocol offers (send/recv) interfaces using mediatek-mailbox APIs.
We use two mbox channels to implement a request-reply protocol.
Signed-off-by: Allen-KH Cheng Allen-KH.Cheng@mediatek.com --- drivers/firmware/Kconfig | 1 + drivers/firmware/Makefile | 1 + drivers/firmware/mediatek/Kconfig | 9 ++ drivers/firmware/mediatek/Makefile | 2 + drivers/firmware/mediatek/mtk-adsp-ipc.c | 138 ++++++++++++++++++ .../linux/firmware/mediatek/mtk-adsp-ipc.h | 70 +++++++++ 6 files changed, 221 insertions(+) create mode 100644 drivers/firmware/mediatek/Kconfig create mode 100644 drivers/firmware/mediatek/Makefile create mode 100644 drivers/firmware/mediatek/mtk-adsp-ipc.c create mode 100644 include/linux/firmware/mediatek/mtk-adsp-ipc.h
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 220a58cf0a44..005f76a9a31a 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -301,6 +301,7 @@ source "drivers/firmware/broadcom/Kconfig" source "drivers/firmware/google/Kconfig" source "drivers/firmware/efi/Kconfig" source "drivers/firmware/imx/Kconfig" +source "drivers/firmware/mediatek/Kconfig" source "drivers/firmware/meson/Kconfig" source "drivers/firmware/psci/Kconfig" source "drivers/firmware/smccc/Kconfig" diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile index 5ced0673d94b..c0d1f3bdeae4 100644 --- a/drivers/firmware/Makefile +++ b/drivers/firmware/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_GOOGLE_FIRMWARE) += google/ obj-$(CONFIG_EFI) += efi/ obj-$(CONFIG_UEFI_CPER) += efi/ obj-y += imx/ +obj-y += mediatek/ obj-y += psci/ obj-y += smccc/ obj-y += tegra/ diff --git a/drivers/firmware/mediatek/Kconfig b/drivers/firmware/mediatek/Kconfig new file mode 100644 index 000000000000..4d4bf9e62508 --- /dev/null +++ b/drivers/firmware/mediatek/Kconfig @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0-only +config MTK_ADSP_IPC + tristate "MTK ADSP IPC Protocol driver" + depends on MTK_ADSP_IPC_MBOX + help + Say yes here to add support for the MediaTek ADSP IPC protocol + between host AP (Linux) and the firmware running on ADSP. + ADSP exists on some mtk processors. + Client might use shared memory to exchange information with ADSP side. diff --git a/drivers/firmware/mediatek/Makefile b/drivers/firmware/mediatek/Makefile new file mode 100644 index 000000000000..4e840b65650d --- /dev/null +++ b/drivers/firmware/mediatek/Makefile @@ -0,0 +1,2 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_MTK_ADSP_IPC) += mtk-adsp-ipc.o diff --git a/drivers/firmware/mediatek/mtk-adsp-ipc.c b/drivers/firmware/mediatek/mtk-adsp-ipc.c new file mode 100644 index 000000000000..33c28f3fbb1a --- /dev/null +++ b/drivers/firmware/mediatek/mtk-adsp-ipc.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2021 MediaTek Corporation. All rights reserved. + * Author: Allen-KH Cheng allen-kh.cheng@mediatek.com + */ + +#include <linux/firmware/mediatek/mtk-adsp-ipc.h> +#include <linux/kernel.h> +#include <linux/mailbox_client.h> +#include <linux/module.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +int adsp_ipc_send(struct mtk_adsp_ipc *ipc, unsigned int idx, uint32_t op) +{ + struct mtk_adsp_chan *dsp_chan; + struct adsp_mbox_ch_info *ch_info; + int ret; + + if (idx >= MTK_ADSP_MBOX_NUM) + return -EINVAL; + + dsp_chan = &ipc->chans[idx]; + ch_info = dsp_chan->ch->con_priv; + ch_info->ipc_op_val = op; + ret = mbox_send_message(dsp_chan->ch, NULL); + if (ret < 0) + return ret; + + return 0; +} +EXPORT_SYMBOL(adsp_ipc_send); + +static void adsp_ipc_recv(struct mbox_client *c, void *msg) +{ + struct mtk_adsp_chan *chan = container_of(c, struct mtk_adsp_chan, cl); + + switch (chan->idx) { + case MTK_ADSP_MBOX_REPLY: + chan->ipc->ops->handle_reply(chan->ipc); + break; + case MTK_ADSP_MBOX_REQUEST: + chan->ipc->ops->handle_request(chan->ipc); + break; + default: + break; + } +} + +static int mtk_adsp_ipc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mtk_adsp_ipc *dsp_ipc; + struct mtk_adsp_chan *dsp_chan; + struct mbox_client *cl; + char *chan_name; + int ret; + int i, j; + + device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent); + + dsp_ipc = devm_kzalloc(dev, sizeof(*dsp_ipc), GFP_KERNEL); + if (!dsp_ipc) + return -ENOMEM; + + for (i = 0; i < MTK_ADSP_MBOX_NUM; i++) { + chan_name = kasprintf(GFP_KERNEL, "mbox%d", i); + if (!chan_name) { + ret = -ENOMEM; + goto out; + } + + dsp_chan = &dsp_ipc->chans[i]; + cl = &dsp_chan->cl; + cl->dev = dev->parent; + cl->tx_block = false; + cl->knows_txdone = false; + cl->tx_prepare = NULL; + cl->rx_callback = adsp_ipc_recv; + + dsp_chan->ipc = dsp_ipc; + dsp_chan->idx = i; + dsp_chan->ch = mbox_request_channel_byname(cl, chan_name); + if (IS_ERR(dsp_chan->ch)) { + ret = PTR_ERR(dsp_chan->ch); + if (ret != -EPROBE_DEFER) + dev_err(dev, "Failed to request mbox chan %d ret %d\n", + i, ret); + goto out; + } + + dev_dbg(dev, "request mbox chan %s\n", chan_name); + kfree(chan_name); + } + + dsp_ipc->dev = dev; + dev_set_drvdata(dev, dsp_ipc); + dev_dbg(dev, "MTK ADSP IPC initialized\n"); + + return 0; + +out: + kfree(chan_name); + for (j = 0; j < i; j++) { + dsp_chan = &dsp_ipc->chans[j]; + mbox_free_channel(dsp_chan->ch); + } + + return ret; +} + +static int mtk_adsp_remove(struct platform_device *pdev) +{ + struct mtk_adsp_ipc *dsp_ipc = dev_get_drvdata(&pdev->dev); + struct mtk_adsp_chan *dsp_chan; + int i; + + for (i = 0; i < MTK_ADSP_MBOX_NUM; i++) { + dsp_chan = &dsp_ipc->chans[i]; + mbox_free_channel(dsp_chan->ch); + } + + return 0; +} + +static struct platform_driver mtk_adsp_ipc_driver = { + .driver = { + .name = "mtk-adsp-ipc", + }, + .probe = mtk_adsp_ipc_probe, + .remove = mtk_adsp_remove, +}; +builtin_platform_driver(mtk_adsp_ipc_driver); + +MODULE_AUTHOR("Allen-KH Cheng allen-kh.cheng@mediatek.com"); +MODULE_DESCRIPTION("MTK ADSP IPC protocol driver"); +MODULE_LICENSE("GPL v2"); diff --git a/include/linux/firmware/mediatek/mtk-adsp-ipc.h b/include/linux/firmware/mediatek/mtk-adsp-ipc.h new file mode 100644 index 000000000000..7f0d1c479b92 --- /dev/null +++ b/include/linux/firmware/mediatek/mtk-adsp-ipc.h @@ -0,0 +1,70 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2021 MediaTek Inc. + */ + +#ifndef MTK_ADSP_IPC_H +#define MTK_ADSP_IPC_H + +#include <linux/device.h> +#include <linux/types.h> +#include <linux/mailbox_controller.h> +#include <linux/mailbox_client.h> + +#define MTK_ADSP_IPC_REQ 0 +#define MTK_ADSP_IPC_RSP 1 +#define MTK_ADSP_IPC_OP_REQ 0x1 +#define MTK_ADSP_IPC_OP_RSP 0x2 + +enum { + MTK_ADSP_MBOX_REPLY, + MTK_ADSP_MBOX_REQUEST, + MTK_ADSP_MBOX_NUM, +}; + +struct mtk_adsp_ipc; + +struct mtk_adsp_ipc_ops { + void (*handle_reply)(struct mtk_adsp_ipc *ipc); + void (*handle_request)(struct mtk_adsp_ipc *ipc); +}; + +struct mtk_adsp_chan { + struct mtk_adsp_ipc *ipc; + struct mbox_client cl; + struct mbox_chan *ch; + char *name; + int idx; +}; + +struct mtk_adsp_ipc { + struct mtk_adsp_chan chans[MTK_ADSP_MBOX_NUM]; + struct device *dev; + struct mtk_adsp_ipc_ops *ops; + void *private_data; +}; + +struct adsp_mbox_ch_info { + u32 ipc_op_val; + void __iomem *va_reg; +}; + +static inline void adsp_ipc_set_data(struct mtk_adsp_ipc *ipc, void *data) +{ + if (!ipc) + return; + + ipc->private_data = data; +} + +static inline void *adsp_ipc_get_data(struct mtk_adsp_ipc *ipc) +{ + if (!ipc) + return NULL; + + return ipc->private_data; +} + +int adsp_ipc_send(struct mtk_adsp_ipc *ipc, unsigned int idx, uint32_t op); + +#endif /* MTK_ADSP_IPC_H */
On Fri, Nov 26, 2021 at 03:14:31PM +0800, allen-kh.cheng wrote:
Signed-off-by: Allen-KH Cheng Allen-KH.Cheng@mediatek.com
Reviewed-by: Tzung-Bi Shih tzungbi@google.com
From: Allen-KH Cheng Allen-KH.Cheng@mediatek.com
This patch is to for MediaTek ADSP IPC mailbox controller driver It is used to send short messages between processors with adsp
Signed-off-by: Allen-KH Cheng Allen-KH.Cheng@mediatek.com --- drivers/mailbox/Kconfig | 7 ++ drivers/mailbox/Makefile | 2 + drivers/mailbox/mtk-adsp-mailbox.c | 178 +++++++++++++++++++++++++++++ 3 files changed, 187 insertions(+) create mode 100644 drivers/mailbox/mtk-adsp-mailbox.c
diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig index c9fc06c7e685..c44a0102585d 100644 --- a/drivers/mailbox/Kconfig +++ b/drivers/mailbox/Kconfig @@ -226,6 +226,13 @@ config STM32_IPCC with hardware for Inter-Processor Communication Controller (IPCC) between processors. Say Y here if you want to have this support.
+config MTK_ADSP_IPC_MBOX + tristate "MediaTek ADSP Mailbox Controller" + depends on ARCH_MEDIATEK || COMPILE_TEST + help + Say yes here to add support for MediaTek ADSP IPC mailbox controller + driver. It is used to send short messages between processors with dsp. + config MTK_CMDQ_MBOX tristate "MediaTek CMDQ Mailbox Support" depends on ARCH_MEDIATEK || COMPILE_TEST diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile index c2089f04887e..13d5c81852ca 100644 --- a/drivers/mailbox/Makefile +++ b/drivers/mailbox/Makefile @@ -49,6 +49,8 @@ obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o
obj-$(CONFIG_STM32_IPCC) += stm32-ipcc.o
+obj-$(CONFIG_MTK_ADSP_IPC_MBOX) += mtk-adsp-mailbox.o + obj-$(CONFIG_MTK_CMDQ_MBOX) += mtk-cmdq-mailbox.o
obj-$(CONFIG_ZYNQMP_IPI_MBOX) += zynqmp-ipi-mailbox.o diff --git a/drivers/mailbox/mtk-adsp-mailbox.c b/drivers/mailbox/mtk-adsp-mailbox.c new file mode 100644 index 000000000000..64be6e30e5a2 --- /dev/null +++ b/drivers/mailbox/mtk-adsp-mailbox.c @@ -0,0 +1,178 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2021 MediaTek Corporation. All rights reserved. + * Author: Allen-KH Cheng allen-kh.cheng@mediatek.com + */ + +#include <linux/firmware/mediatek/mtk-adsp-ipc.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/iopoll.h> +#include <linux/kernel.h> +#include <linux/mailbox_controller.h> +#include <linux/module.h> +#include <linux/of_device.h> +#include <linux/slab.h> + +/* adsp mbox register offset */ +#define MTK_ADSP_MBOX_IN_CMD 0x00 +#define MTK_ADSP_MBOX_IN_CMD_CLR 0x04 +#define MTK_ADSP_MBOX_OUT_CMD 0x1c +#define MTK_ADSP_MBOX_OUT_CMD_CLR 0x20 +#define MTK_ADSP_MBOX_IN_MSG0 0x08 +#define MTK_ADSP_MBOX_IN_MSG1 0x0C +#define MTK_ADSP_MBOX_OUT_MSG0 0x24 +#define MTK_ADSP_MBOX_OUT_MSG1 0x28 + +struct mtk_adsp_mbox_priv { + struct device *dev; + struct mbox_controller mbox; + void __iomem *va_mboxreg; +}; + +static irqreturn_t mtk_adsp_ipc_irq_handler(int irq, void *data) +{ + struct mbox_chan *ch = data; + struct adsp_mbox_ch_info *ch_info = ch->con_priv; + void __iomem *reg = ch_info->va_reg; + u32 op = readl(reg + MTK_ADSP_MBOX_OUT_CMD); + + writel(op, reg + MTK_ADSP_MBOX_OUT_CMD_CLR); + + return IRQ_WAKE_THREAD; +} + +static irqreturn_t mtk_adsp_ipc_handler(int irq, void *data) +{ + struct mbox_chan *ch = data; + struct adsp_mbox_ch_info *ch_info = ch->con_priv; + + mbox_chan_received_data(ch, ch_info); + + return IRQ_HANDLED; +} + +static struct mbox_chan *mtk_adsp_mbox_xlate(struct mbox_controller *mbox, + const struct of_phandle_args *sp) +{ + return &mbox->chans[sp->args[0]]; +} + +static int mtk_adsp_mbox_startup(struct mbox_chan *chan) +{ + struct adsp_mbox_ch_info *ch_info = chan->con_priv; + void __iomem *reg = ch_info->va_reg; + + /* Clear DSP mbox command */ + writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_IN_CMD_CLR); + writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_OUT_CMD_CLR); + + return 0; +} + +static void mtk_adsp_mbox_shutdown(struct mbox_chan *chan) +{ + struct adsp_mbox_ch_info *ch_info = chan->con_priv; + void __iomem *reg = ch_info->va_reg; + + /* Clear DSP mbox command */ + writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_IN_CMD_CLR); + writel(0xFFFFFFFF, reg + MTK_ADSP_MBOX_OUT_CMD_CLR); + chan->con_priv = NULL; +} + +static int mtk_adsp_mbox_send_data(struct mbox_chan *chan, void *data) +{ + struct adsp_mbox_ch_info *ch_info = chan->con_priv; + void __iomem *reg = ch_info->va_reg; + + writel(ch_info->ipc_op_val, reg + MTK_ADSP_MBOX_IN_CMD); + + return 0; +} + +static bool mtk_adsp_mbox_last_tx_done(struct mbox_chan *chan) +{ + struct adsp_mbox_ch_info *ch_info = chan->con_priv; + void __iomem *reg = ch_info->va_reg; + + return readl(reg + MTK_ADSP_MBOX_IN_CMD) == 0 ? true : false; +} + +static const struct mbox_chan_ops adsp_mbox_chan_ops = { + .send_data = mtk_adsp_mbox_send_data, + .startup = mtk_adsp_mbox_startup, + .shutdown = mtk_adsp_mbox_shutdown, + .last_tx_done = mtk_adsp_mbox_last_tx_done, +}; + +static int mtk_adsp_mbox_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct mbox_controller *mbox; + struct mtk_adsp_mbox_priv *priv; + struct resource *res; + struct adsp_mbox_ch_info *ch_info; + int ret; + int irq; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + mbox = &priv->mbox; + mbox->dev = dev; + mbox->ops = &adsp_mbox_chan_ops; + mbox->txdone_irq = false; + mbox->txdone_poll = true; + mbox->of_xlate = mtk_adsp_mbox_xlate; + mbox->num_chans = 1; + mbox->chans = devm_kzalloc(mbox->dev, sizeof(*mbox->chans), GFP_KERNEL); + if (!mbox->chans) + return -ENOMEM; + + priv->va_mboxreg = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->va_mboxreg)) + return PTR_ERR(priv->va_mboxreg); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_threaded_irq(dev, irq, + mtk_adsp_ipc_irq_handler, mtk_adsp_ipc_handler, + IRQF_TRIGGER_NONE, dev_name(dev), + mbox->chans); + if (ret < 0) + return ret; + + /* set adsp mbox channel info */ + ch_info = devm_kzalloc(dev, sizeof(*ch_info), GFP_KERNEL); + if (!ch_info) + return -ENOMEM; + + ch_info->va_reg = priv->va_mboxreg; + mbox->chans->con_priv = ch_info; + platform_set_drvdata(pdev, priv); + + return devm_mbox_controller_register(dev, &priv->mbox); +} + +static const struct of_device_id mtk_adsp_mbox_of_match[] = { + { .compatible = "mediatek,mt8195-adsp-mbox", }, + {}, +}; +MODULE_DEVICE_TABLE(of, mtk_adsp_mbox_of_match); + +static struct platform_driver mtk_adsp_ipc_mbox_driver = { + .probe = mtk_adsp_mbox_probe, + .driver = { + .name = "mtk_adsp_mbox", + .of_match_table = mtk_adsp_mbox_of_match, + }, +}; +module_platform_driver(mtk_adsp_ipc_mbox_driver); + +MODULE_AUTHOR("Allen-KH Cheng Allen-KH.Cheng@mediatek.com"); +MODULE_DESCRIPTION("MTK ADSP mailbox IPC driver"); +MODULE_LICENSE("GPL v2");
On Fri, Nov 26, 2021 at 03:14:32PM +0800, allen-kh.cheng wrote:
diff --git a/drivers/mailbox/mtk-adsp-mailbox.c b/drivers/mailbox/mtk-adsp-mailbox.c
[...]
+static bool mtk_adsp_mbox_last_tx_done(struct mbox_chan *chan) +{
- struct adsp_mbox_ch_info *ch_info = chan->con_priv;
- void __iomem *reg = ch_info->va_reg;
- return readl(reg + MTK_ADSP_MBOX_IN_CMD) == 0 ? true : false;
The expression "readl(...) == 0" should be already a boolean.
participants (2)
-
allen-kh.cheng
-
Tzung-Bi Shih