On 2020/12/01 20:02, conor.dooley@xxxxxxxxxxxxx wrote:
> From: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
>
> This driver adds support for the single mailbox channel of the MSS
> system controller on the Microchip PolarFire SoC.
>
> Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> ---
> drivers/mailbox/Kconfig | 12 ++
> drivers/mailbox/Makefile | 2 +
> drivers/mailbox/mailbox-mpfs.c | 285 +++++++++++++++++++++++++++++++++
> include/soc/microchip/mpfs.h | 51 ++++++
> 4 files changed, 350 insertions(+)
> create mode 100644 drivers/mailbox/mailbox-mpfs.c
> create mode 100644 include/soc/microchip/mpfs.h
>
> diff --git a/drivers/mailbox/Kconfig b/drivers/mailbox/Kconfig
> index 05b1009e2820..fbf6902c3541 100644
> --- a/drivers/mailbox/Kconfig
> +++ b/drivers/mailbox/Kconfig
> @@ -153,6 +153,18 @@ config MAILBOX_TEST
> Test client to help with testing new Controller driver
> implementations.
>
> +config MPFS_MBOX
> + tristate "MPFS Mailbox"
> + depends on HAS_IOMEM
> + depends on SOC_MICROCHIP_POLARFIRE || COMPILE_TEST
> + help
> + This driver adds support for the Polarfire SoC mailbox controller.
> +
> + To compile this driver as a module, choose M here. the
> + module will be called mailbox-mpfs.
> +
> + If unsure, say N.
> +
> config QCOM_APCS_IPC
> tristate "Qualcomm APCS IPC driver"
> depends on ARCH_QCOM || COMPILE_TEST
> diff --git a/drivers/mailbox/Makefile b/drivers/mailbox/Makefile
> index 2e06e02b2e03..63f49b5bcc43 100644
> --- a/drivers/mailbox/Makefile
> +++ b/drivers/mailbox/Makefile
> @@ -39,6 +39,8 @@ obj-$(CONFIG_BCM_PDC_MBOX) += bcm-pdc-mailbox.o
>
> obj-$(CONFIG_BCM_FLEXRM_MBOX) += bcm-flexrm-mailbox.o
>
> +obj-$(CONFIG_MPFS_MBOX) += mailbox-mpfs.o
> +
> obj-$(CONFIG_QCOM_APCS_IPC) += qcom-apcs-ipc-mailbox.o
>
> obj-$(CONFIG_TEGRA_HSP_MBOX) += tegra-hsp.o
> diff --git a/drivers/mailbox/mailbox-mpfs.c b/drivers/mailbox/mailbox-mpfs.c
> new file mode 100644
> index 000000000000..e1ecf3081312
> --- /dev/null
> +++ b/drivers/mailbox/mailbox-mpfs.c
> @@ -0,0 +1,285 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Microchip MPFS system controller/mailbox controller driver
> + *
> + * Copyright (c) 2020 Microchip Corporation. All rights reserved.
> + *
> + * Author: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> + *
> + */
> +
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/interrupt.h>
> +#include <linux/platform_device.h>
> +#include <linux/mailbox_controller.h>
> +#include <soc/microchip/mpfs.h>
> +
> +#define SERVICES_CR_OFFSET 0x50u
> +#define SERVICES_SR_OFFSET 0x54u
> +#define MAILBOX_REG_OFFSET 0x800u
> +#define MSS_SYS_BUSY -EBUSY
> +#define MSS_SYS_PARAM_ERR -EINVAL
> +#define MSS_SYS_MAILBOX_DATA_OFFSET 0u
> +#define SCB_MASK_WIDTH 16u
Value identation seems off here. Aligning it would be nice.
> +/* SCBCTRL service control register */
> +
> +#define SCB_CTRL_REQ (0u)
> +#define SCB_CTRL_REQ_MASK BIT(SCB_CTRL_REQ)
> +
> +#define SCB_CTRL_BUSY (1u)
> +#define SCB_CTRL_BUSY_MASK BIT(SCB_CTRL_BUSY)
> +
> +#define SCB_CTRL_ABORT (2u)
> +#define SCB_CTRL_ABORT_MASK BIT(SCB_CTRL_ABORT)
> +
> +#define SCB_CTRL_NOTIFY (3u)
> +#define SCB_CTRL_NOTIFY_MASK BIT(SCB_CTRL_NOTIFY)
> +
> +#define SCB_CTRL_POS (16u)
> +#define SCB_CTRL_MASK GENMASK(SCB_CTRL_POS+SCB_MASK_WIDTH, SCB_CTRL_POS)
Please add spaces before and after the "+" operator.
And I am really not a big fan of the (useless in my opinion) "u" for unsigned
for all of these.
> +
> +/* SCBCTRL service status registers */
> +
> +#define SCB_STATUS_REQ (0u)
> +#define SCB_STATUS_REQ_MASK BIT(SCB_STATUS_REQ)
> +
> +#define SCB_STATUS_BUSY (1u)
> +#define SCB_STATUS_BUSY_MASK BIT(SCB_STATUS_BUSY)
> +
> +#define SCB_STATUS_ABORT (2u)
> +#define SCB_STATUS_ABORT_MASK BIT(SCB_STATUS_ABORT)
> +
> +#define SCB_STATUS_NOTIFY (3u)
> +#define SCB_STATUS_NOTIFY_MASK BIT(SCB_STATUS_NOTIFY)
> +
> +#define SCB_STATUS_POS (16u)
> +#define SCB_STATUS_MASK GENMASK(SCB_STATUS_POS+SCB_MASK_WIDTH, SCB_STATUS_POS)
Spaces around "+".
> +
> +struct mpfs_mbox {
> + struct mbox_controller controller;
> + struct device *dev;
> + int irq;
> + void __iomem *mailbox_base;
> + void __iomem *int_reg;
> + struct mbox_chan *chan;
> + u16 response_size;
> + u16 response_offset;
> +};
> +
> +static bool mpfs_mbox_busy(struct mpfs_mbox *mbox)
> +{
> + u32 status;
> +
> + status = readl_relaxed(mbox->mailbox_base + SERVICES_SR_OFFSET);
> +
> + return status & SCB_STATUS_BUSY_MASK;
> +}
> +
> +static struct mpfs_mbox *mbox_chan_to_mpfs_mbox(struct mbox_chan *chan)
> +{
> + if (!chan || !chan->con_priv)
> + return NULL;
You do not need the "|| !chan->con_priv" here. The return below will return NULL.
> +
> + return (struct mpfs_mbox *)chan->con_priv;
> +}
> +
> +static int mpfs_mbox_send_data(struct mbox_chan *chan, void *data)
> +{
> + u32 index;
> + u32 *word_buf;
> + u8 *byte_buf;
> + u8 byte_off;
> + u8 i;
> + u32 mailbox_val = 0u;
> + u16 mb_offset;
> + u16 mbox_options_select;
> + u32 mbox_tx_trigger;
> + struct mpfs_mss_msg *msg = data;
> + struct mpfs_mbox *mbox = mbox_chan_to_mpfs_mbox(chan);
> + mb_offset = msg->mailbox_offset;
> + mbox->response_size = msg->response_size;
> + mbox->response_offset = msg->response_offset;
> +
> + if (mpfs_mbox_busy(mbox))
> + return MSS_SYS_BUSY;
> +
> + mbox_options_select = ((mb_offset << 7u) | (msg->cmd_opcode & 0x7fu));
> + mbox_tx_trigger = (((mbox_options_select << SCB_CTRL_POS) &
> + SCB_CTRL_MASK) | SCB_CTRL_REQ_MASK | SCB_STATUS_NOTIFY_MASK);
> +
> + /* Code for MSS_SYS_PARAM_ERR is not implemented with this version of driver. */
> +
> + writel_relaxed(0x0u, mbox->int_reg);
0x0u seems like an awfully complicated way of writing 0. Less characters for the
brain to decode makes reading easier :)
> +
> + if (msg->cmd_data_size) {
> + byte_buf = (u8 *)(msg->cmd_data);
> +
> + for (index = 0; index < (msg->cmd_data_size / 4); index++) {
> + writel_relaxed(word_buf[index],
> + mbox->mailbox_base + MAILBOX_REG_OFFSET + index);
> + }
You do not need the braces here.
> +
> + if ((msg->cmd_data_size % 4) > 0) {
s/% 4/& 3. And you do not need the "> 0".
> + byte_off = (((msg->cmd_data_size / 4) * 4));
Extra outside parenthesis not needed.
byte_off = msg->cmd_data_size & (~3);
or
byte_off = ALIGN_DOWN(msg->cmd_data_size, 4);
> + byte_buf = (u8 *)(msg->cmd_data + byte_off);
cmd_data is already u8 *, so you do not need the cast.
> +
> + mailbox_val = readl_relaxed(mbox->mailbox_base +
> + MAILBOX_REG_OFFSET + index);
> +
> + for (i = 0u; i < (msg->cmd_data_size % 4u); i++) {
% 4 -> & 3
And since you already have taht in the if above, why not use a local variable ?
> + mailbox_val &= ~(0xffu << (i * 8u));
> + mailbox_val |= (byte_buf[i] << (i * 8u));
> + }
> +
> + writel_relaxed(mailbox_val, mbox->mailbox_base + MAILBOX_REG_OFFSET + index);
> + }
> + }
> +
> + writel_relaxed(mbox_tx_trigger, mbox->mailbox_base + SERVICES_CR_OFFSET);
> +
> + return 0;
> +}
> +
> +static inline bool mpfs_mbox_pending(struct mpfs_mbox *mbox)
> +{
> + u32 status;
> +
> + status = readl_relaxed(mbox->mailbox_base + SERVICES_SR_OFFSET);
> +
> + return !(status & SCB_STATUS_BUSY_MASK);
> +}
> +
> +static void mpfs_mbox_rx_data(struct mbox_chan *chan)
> +{
> + struct mpfs_mbox *mbox = mbox_chan_to_mpfs_mbox(chan);
> + u32 *data;
> + u32 i;
> + u32 response_limit;
> +
> + data = devm_kzalloc(mbox->dev, sizeof(*data) * mbox->response_size, GFP_ATOMIC);
> + if (!data)
> + dev_err(mbox->dev, "failed to register mailbox interrupt:%d\n", -ENOMEM);
> +
> + response_limit = (mbox->response_size) + (mbox->response_offset);
> + if (mpfs_mbox_pending(mbox) && mbox->response_size > 0U) {
> + for (i = (mbox->response_offset); i < response_limit; i++) {
Parenthesis not needed around (mbox->response_offset).
> + data[i - (mbox->response_offset)] =
Same here.
> + readl_relaxed(mbox->mailbox_base + MAILBOX_REG_OFFSET + i * 0x4);
> + }
> + }
> +
> + mbox_chan_received_data(chan, (void *)data);
> + devm_kfree(mbox->dev, data);
> +}
> +
> +static irqreturn_t mpfs_mbox_inbox_isr(int irq, void *data)
> +{
> + struct mbox_chan *chan = (struct mbox_chan *)data;
> + struct mpfs_mbox *mbox = mbox_chan_to_mpfs_mbox(chan);
> +
> + writel_relaxed(0x0U, mbox->int_reg);
0x0U == 0...
> +
> + mpfs_mbox_rx_data(chan);
> +
> + mbox_chan_txdone(chan, 0);
> + return IRQ_HANDLED;
> +}
> +
> +static int mpfs_mbox_startup(struct mbox_chan *chan)
> +{
> + struct mpfs_mbox *mbox = mbox_chan_to_mpfs_mbox(chan);
> + int ret = 0;
> +
> + if (!mbox)
> + return -EINVAL;
> + ret = devm_request_irq(mbox->dev, mbox->irq, mpfs_mbox_inbox_isr, 0, "mpfs-mailbox", chan);
> + if (ret) {
> + dev_err(mbox->dev, "failed to register mailbox interrupt:%d\n", ret);
> + }
No need for the curly braces.
> +
> + return ret;
> +}
> +
> +static void mpfs_mbox_shutdown(struct mbox_chan *chan)
> +{
> + struct mpfs_mbox *mbox = mbox_chan_to_mpfs_mbox(chan);
> +
> + devm_free_irq(mbox->dev, mbox->irq, chan);
> +}
> +
> +static const struct mbox_chan_ops mpfs_mbox_ops = {
> + .send_data = mpfs_mbox_send_data,
> + .startup = mpfs_mbox_startup,
> + .shutdown = mpfs_mbox_shutdown,
> +};
> +
> +static int mpfs_mbox_probe(struct platform_device *pdev)
> +{
> + struct mpfs_mbox *mbox;
> + struct resource *regs;
> + struct mbox_chan *chans;
> + int ret;
> +
> + mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
> + if (!mbox)
> + return -ENOMEM;
> +
> + chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
> + if (!chans)
> + return -ENOMEM;
> +
> + mbox->mailbox_base = devm_platform_get_and_ioremap_resource(pdev, 0, ®s);
> + if (IS_ERR(mbox->mailbox_base))
> + return PTR_ERR(mbox->mailbox_base);
> +
> + mbox->int_reg = devm_platform_get_and_ioremap_resource(pdev, 1, ®s);
> + if (IS_ERR(mbox->int_reg))
> + return PTR_ERR(mbox->int_reg);
> +
> + mbox->irq = platform_get_irq(pdev, 0);
> + if (mbox->irq < 0)
> + return mbox->irq;
> +
> + mbox->dev = &pdev->dev;
> +
> + chans[0].con_priv = mbox;
> + mbox->controller.dev = mbox->dev;
> + mbox->controller.num_chans = 1;
> + mbox->controller.chans = chans;
> + mbox->controller.ops = &mpfs_mbox_ops;
> + mbox->controller.txdone_irq = true;
> +
> + ret = devm_mbox_controller_register(&pdev->dev, &mbox->controller);
> + if (ret) {
> + dev_err(&pdev->dev, "Registering MPFS mailbox controller failed\n");
> + return ret;
> + }
> + dev_info(&pdev->dev, "Registered MPFS mailbox controller driver\n");
> +
> + return 0;
> +}
> +
> +static const struct of_device_id mpfs_mbox_of_match[] = {
> + {
> + .compatible = "microchip,polarfire-soc-mailbox",
> + },
> + {},
> +};
The typical way of writing this is:
static const struct of_device_id mpfs_mbox_of_match[] = {
{ .compatible = "microchip,polarfire-soc-mailbox", },
{}
};
> +MODULE_DEVICE_TABLE(of, mpfs_mbox_of_match);
> +
> +static struct platform_driver mpfs_mbox_driver = {
> + .driver = {
> + .name = "mpfs-mailbox",
> + .of_match_table = mpfs_mbox_of_match,
> + },
> + .probe = mpfs_mbox_probe,
> +};
> +module_platform_driver(mpfs_mbox_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Conor Dooley <conor.dooley@xxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("MPFS mailbox controller driver");
> diff --git a/include/soc/microchip/mpfs.h b/include/soc/microchip/mpfs.h
> new file mode 100644
> index 000000000000..b231f39f32eb
> --- /dev/null
> +++ b/include/soc/microchip/mpfs.h
> @@ -0,0 +1,51 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + *
> + * Microchip MPFS mailbox
> + *
> + * Copyright (c) 2020 Microchip Corporation. All rights reserved.
> + *
> + * Author: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
> + *
> + */
> +
> +#ifndef __SOC_MPFS_H__
> +#define __SOC_MPFS_H__
> +
> +#include <linux/types.h>
> +#include <linux/of_device.h>
> +
> +struct mpfs_sys_controller;
> +
> +struct mpfs_mss_msg {
> + u8 cmd_opcode;
> + u16 cmd_data_size;
> + u16 response_size;
> + u8 *cmd_data;
> + u16 mailbox_offset;
> + u16 response_offset;
> +};
> +
> +#if IS_ENABLED(CONFIG_MPFS_SYS_CONTROLLER)
A simple #ifdef would do.
> +
> +int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, void *msg,
> + void *response, u16 response_size_bytes);
> +
> +struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node);
> +
> +#else
> +
> +static int mpfs_blocking_transaction(struct mpfs_sys_controller *mpfs_client, void *msg,
> + void *response, u16 response_size_bytes)
> +{
> + return -ENOSYS;
> +};
> +
> +struct mpfs_sys_controller *mpfs_sys_controller_get(struct device_node *mailbox_node)
> +{
> + return NULL;
> +}
> +
> +#endif /* IS_ENABLED(CONFIG_MPFS_SYS_CONTROLLER) */
> +
> +#endif /* __SOC_MPFS_H__ */
>
--
Damien Le Moal
Western Digital Research
