diff options
Diffstat (limited to 'drivers/mailbox/mailbox-mpfs.c')
| -rw-r--r-- | drivers/mailbox/mailbox-mpfs.c | 287 |
1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/mailbox/mailbox-mpfs.c b/drivers/mailbox/mailbox-mpfs.c new file mode 100644 index 0000000000..20ee283a04 --- /dev/null +++ b/drivers/mailbox/mailbox-mpfs.c @@ -0,0 +1,287 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Microchip PolarFire SoC (MPFS) system controller/mailbox controller driver + * + * Copyright (c) 2020-2022 Microchip Corporation. All rights reserved. + * + * Author: Conor Dooley <conor.dooley@microchip.com> + * + */ + +#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/mod_devicetable.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_MAILBOX_DATA_OFFSET 0u +#define SCB_MASK_WIDTH 16u + +/* SCBCTRL service control register */ + +#define SCB_CTRL_REQ (0) +#define SCB_CTRL_REQ_MASK BIT(SCB_CTRL_REQ) + +#define SCB_CTRL_BUSY (1) +#define SCB_CTRL_BUSY_MASK BIT(SCB_CTRL_BUSY) + +#define SCB_CTRL_ABORT (2) +#define SCB_CTRL_ABORT_MASK BIT(SCB_CTRL_ABORT) + +#define SCB_CTRL_NOTIFY (3) +#define SCB_CTRL_NOTIFY_MASK BIT(SCB_CTRL_NOTIFY) + +#define SCB_CTRL_POS (16) +#define SCB_CTRL_MASK GENMASK(SCB_CTRL_POS + SCB_MASK_WIDTH - 1, SCB_CTRL_POS) + +/* SCBCTRL service status register */ + +#define SCB_STATUS_REQ (0) +#define SCB_STATUS_REQ_MASK BIT(SCB_STATUS_REQ) + +#define SCB_STATUS_BUSY (1) +#define SCB_STATUS_BUSY_MASK BIT(SCB_STATUS_BUSY) + +#define SCB_STATUS_ABORT (2) +#define SCB_STATUS_ABORT_MASK BIT(SCB_STATUS_ABORT) + +#define SCB_STATUS_NOTIFY (3) +#define SCB_STATUS_NOTIFY_MASK BIT(SCB_STATUS_NOTIFY) + +#define SCB_STATUS_POS (16) +#define SCB_STATUS_MASK GENMASK(SCB_STATUS_POS + SCB_MASK_WIDTH - 1, SCB_STATUS_POS) + +struct mpfs_mbox { + struct mbox_controller controller; + struct device *dev; + int irq; + void __iomem *ctrl_base; + void __iomem *mbox_base; + void __iomem *int_reg; + struct mbox_chan chans[1]; + struct mpfs_mss_response *response; + u16 resp_offset; +}; + +static bool mpfs_mbox_busy(struct mpfs_mbox *mbox) +{ + u32 status; + + status = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET); + + return status & SCB_STATUS_BUSY_MASK; +} + +static bool mpfs_mbox_last_tx_done(struct mbox_chan *chan) +{ + struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv; + struct mpfs_mss_response *response = mbox->response; + u32 val; + + if (mpfs_mbox_busy(mbox)) + return false; + + /* + * The service status is stored in bits 31:16 of the SERVICES_SR + * register & is only valid when the system controller is not busy. + * Failed services are intended to generated interrupts, but in reality + * this does not happen, so the status must be checked here. + */ + val = readl_relaxed(mbox->ctrl_base + SERVICES_SR_OFFSET); + response->resp_status = (val & SCB_STATUS_MASK) >> SCB_STATUS_POS; + + return true; +} + +static int mpfs_mbox_send_data(struct mbox_chan *chan, void *data) +{ + struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv; + struct mpfs_mss_msg *msg = data; + u32 tx_trigger; + u16 opt_sel; + u32 val = 0u; + + mbox->response = msg->response; + mbox->resp_offset = msg->resp_offset; + + if (mpfs_mbox_busy(mbox)) + return -EBUSY; + + if (msg->cmd_data_size) { + u32 index; + u8 extra_bits = msg->cmd_data_size & 3; + u32 *word_buf = (u32 *)msg->cmd_data; + + for (index = 0; index < (msg->cmd_data_size / 4); index++) + writel_relaxed(word_buf[index], + mbox->mbox_base + msg->mbox_offset + index * 0x4); + if (extra_bits) { + u8 i; + u8 byte_off = ALIGN_DOWN(msg->cmd_data_size, 4); + u8 *byte_buf = msg->cmd_data + byte_off; + + val = readl_relaxed(mbox->mbox_base + msg->mbox_offset + index * 0x4); + + for (i = 0u; i < extra_bits; i++) { + val &= ~(0xffu << (i * 8u)); + val |= (byte_buf[i] << (i * 8u)); + } + + writel_relaxed(val, mbox->mbox_base + msg->mbox_offset + index * 0x4); + } + } + + opt_sel = ((msg->mbox_offset << 7u) | (msg->cmd_opcode & 0x7fu)); + + tx_trigger = (opt_sel << SCB_CTRL_POS) & SCB_CTRL_MASK; + tx_trigger |= SCB_CTRL_REQ_MASK | SCB_STATUS_NOTIFY_MASK; + writel_relaxed(tx_trigger, mbox->ctrl_base + SERVICES_CR_OFFSET); + + return 0; +} + +static void mpfs_mbox_rx_data(struct mbox_chan *chan) +{ + struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv; + struct mpfs_mss_response *response = mbox->response; + u16 num_words = ALIGN((response->resp_size), (4)) / 4U; + u32 i; + + if (!response->resp_msg) { + dev_err(mbox->dev, "failed to assign memory for response %d\n", -ENOMEM); + return; + } + + /* + * We should *never* get an interrupt while the controller is + * still in the busy state. If we do, something has gone badly + * wrong & the content of the mailbox would not be valid. + */ + if (mpfs_mbox_busy(mbox)) { + dev_err(mbox->dev, "got an interrupt but system controller is busy\n"); + response->resp_status = 0xDEAD; + return; + } + + for (i = 0; i < num_words; i++) { + response->resp_msg[i] = + readl_relaxed(mbox->mbox_base + + mbox->resp_offset + i * 0x4); + } + + mbox_chan_received_data(chan, response); +} + +static irqreturn_t mpfs_mbox_inbox_isr(int irq, void *data) +{ + struct mbox_chan *chan = data; + struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv; + + writel_relaxed(0, mbox->int_reg); + + mpfs_mbox_rx_data(chan); + + return IRQ_HANDLED; +} + +static int mpfs_mbox_startup(struct mbox_chan *chan) +{ + struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv; + 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); + + return ret; +} + +static void mpfs_mbox_shutdown(struct mbox_chan *chan) +{ + struct mpfs_mbox *mbox = (struct mpfs_mbox *)chan->con_priv; + + 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, + .last_tx_done = mpfs_mbox_last_tx_done, +}; + +static int mpfs_mbox_probe(struct platform_device *pdev) +{ + struct mpfs_mbox *mbox; + struct resource *regs; + int ret; + + mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL); + if (!mbox) + return -ENOMEM; + + mbox->ctrl_base = devm_platform_get_and_ioremap_resource(pdev, 0, ®s); + if (IS_ERR(mbox->ctrl_base)) + return PTR_ERR(mbox->ctrl_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->mbox_base = devm_platform_get_and_ioremap_resource(pdev, 2, ®s); + if (IS_ERR(mbox->mbox_base)) // account for the old dt-binding w/ 2 regs + mbox->mbox_base = mbox->ctrl_base + MAILBOX_REG_OFFSET; + + mbox->irq = platform_get_irq(pdev, 0); + if (mbox->irq < 0) + return mbox->irq; + + mbox->dev = &pdev->dev; + + mbox->chans[0].con_priv = mbox; + mbox->controller.dev = mbox->dev; + mbox->controller.num_chans = 1; + mbox->controller.chans = mbox->chans; + mbox->controller.ops = &mpfs_mbox_ops; + mbox->controller.txdone_poll = true; + mbox->controller.txpoll_period = 10u; + + 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,mpfs-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@microchip.com>"); +MODULE_DESCRIPTION("MPFS mailbox controller driver"); |