diff options
Diffstat (limited to 'drivers/mailbox/ast2700-mailbox.c')
| -rw-r--r-- | drivers/mailbox/ast2700-mailbox.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/mailbox/ast2700-mailbox.c b/drivers/mailbox/ast2700-mailbox.c new file mode 100644 index 000000000000..83c6afe5411f --- /dev/null +++ b/drivers/mailbox/ast2700-mailbox.c @@ -0,0 +1,235 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright Aspeed Technology Inc. (C) 2025. All rights reserved + */ + +#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.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +/* Each bit in the register represents an IPC ID */ +#define IPCR_TX_TRIG 0x00 +#define IPCR_ENABLE 0x04 +#define IPCR_STATUS 0x08 +#define RX_IRQ(n) BIT(n) +#define RX_IRQ_MASK 0xf +#define IPCR_DATA 0x10 + +struct ast2700_mbox_data { + u8 num_chans; + u8 msg_size; +}; + +struct ast2700_mbox { + struct mbox_controller mbox; + u8 msg_size; + void __iomem *tx_regs; + void __iomem *rx_regs; + spinlock_t lock; +}; + +static inline int ch_num(struct mbox_chan *chan) +{ + return chan - chan->mbox->chans; +} + +static inline bool ast2700_mbox_tx_done(struct ast2700_mbox *mb, int idx) +{ + return !(readl(mb->tx_regs + IPCR_STATUS) & BIT(idx)); +} + +static irqreturn_t ast2700_mbox_irq(int irq, void *p) +{ + struct ast2700_mbox *mb = p; + void __iomem *data_reg; + int num_words = mb->msg_size / sizeof(u32); + u32 *word_data; + u32 status; + int n, i; + + /* Only examine channels that are currently enabled. */ + status = readl(mb->rx_regs + IPCR_ENABLE) & + readl(mb->rx_regs + IPCR_STATUS); + + if (!(status & RX_IRQ_MASK)) + return IRQ_NONE; + + for (n = 0; n < mb->mbox.num_chans; ++n) { + struct mbox_chan *chan = &mb->mbox.chans[n]; + + if (!(status & RX_IRQ(n))) + continue; + + data_reg = mb->rx_regs + IPCR_DATA + mb->msg_size * n; + word_data = chan->con_priv; + /* Read the message data */ + for (i = 0; i < num_words; i++) + word_data[i] = readl(data_reg + i * sizeof(u32)); + + mbox_chan_received_data(chan, chan->con_priv); + + /* The IRQ can be cleared only once the FIFO is empty. */ + writel(RX_IRQ(n), mb->rx_regs + IPCR_STATUS); + } + + return IRQ_HANDLED; +} + +static int ast2700_mbox_send_data(struct mbox_chan *chan, void *data) +{ + struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev); + int idx = ch_num(chan); + void __iomem *data_reg = mb->tx_regs + IPCR_DATA + mb->msg_size * idx; + u32 *word_data = data; + int num_words = mb->msg_size / sizeof(u32); + int i; + + if (!(readl(mb->tx_regs + IPCR_ENABLE) & BIT(idx))) { + dev_warn(mb->mbox.dev, "%s: Ch-%d not enabled yet\n", __func__, idx); + return -ENODEV; + } + + if (!(ast2700_mbox_tx_done(mb, idx))) { + dev_warn(mb->mbox.dev, "%s: Ch-%d last data has not finished\n", __func__, idx); + return -EBUSY; + } + + /* Write the message data */ + for (i = 0 ; i < num_words; i++) + writel(word_data[i], data_reg + i * sizeof(u32)); + + writel(BIT(idx), mb->tx_regs + IPCR_TX_TRIG); + dev_dbg(mb->mbox.dev, "%s: Ch-%d sent\n", __func__, idx); + + return 0; +} + +static int ast2700_mbox_startup(struct mbox_chan *chan) +{ + struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev); + int idx = ch_num(chan); + void __iomem *reg = mb->rx_regs + IPCR_ENABLE; + unsigned long flags; + + spin_lock_irqsave(&mb->lock, flags); + writel(readl(reg) | BIT(idx), reg); + spin_unlock_irqrestore(&mb->lock, flags); + + return 0; +} + +static void ast2700_mbox_shutdown(struct mbox_chan *chan) +{ + struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev); + int idx = ch_num(chan); + void __iomem *reg = mb->rx_regs + IPCR_ENABLE; + unsigned long flags; + + spin_lock_irqsave(&mb->lock, flags); + writel(readl(reg) & ~BIT(idx), reg); + spin_unlock_irqrestore(&mb->lock, flags); +} + +static bool ast2700_mbox_last_tx_done(struct mbox_chan *chan) +{ + struct ast2700_mbox *mb = dev_get_drvdata(chan->mbox->dev); + int idx = ch_num(chan); + + return ast2700_mbox_tx_done(mb, idx); +} + +static const struct mbox_chan_ops ast2700_mbox_chan_ops = { + .send_data = ast2700_mbox_send_data, + .startup = ast2700_mbox_startup, + .shutdown = ast2700_mbox_shutdown, + .last_tx_done = ast2700_mbox_last_tx_done, +}; + +static int ast2700_mbox_probe(struct platform_device *pdev) +{ + struct ast2700_mbox *mb; + const struct ast2700_mbox_data *dev_data; + struct device *dev = &pdev->dev; + int irq, ret; + + if (!pdev->dev.of_node) + return -ENODEV; + + dev_data = device_get_match_data(&pdev->dev); + + mb = devm_kzalloc(dev, sizeof(*mb), GFP_KERNEL); + if (!mb) + return -ENOMEM; + + mb->mbox.chans = devm_kcalloc(&pdev->dev, dev_data->num_chans, + sizeof(*mb->mbox.chans), GFP_KERNEL); + if (!mb->mbox.chans) + return -ENOMEM; + + /* con_priv of each channel is used to store the message received */ + for (int i = 0; i < dev_data->num_chans; i++) { + mb->mbox.chans[i].con_priv = devm_kcalloc(dev, dev_data->msg_size, + sizeof(u8), GFP_KERNEL); + if (!mb->mbox.chans[i].con_priv) + return -ENOMEM; + } + + platform_set_drvdata(pdev, mb); + + mb->tx_regs = devm_platform_ioremap_resource_byname(pdev, "tx"); + if (IS_ERR(mb->tx_regs)) + return PTR_ERR(mb->tx_regs); + + mb->rx_regs = devm_platform_ioremap_resource_byname(pdev, "rx"); + if (IS_ERR(mb->rx_regs)) + return PTR_ERR(mb->rx_regs); + + mb->msg_size = dev_data->msg_size; + mb->mbox.dev = dev; + mb->mbox.num_chans = dev_data->num_chans; + mb->mbox.ops = &ast2700_mbox_chan_ops; + mb->mbox.txdone_irq = false; + mb->mbox.txdone_poll = true; + mb->mbox.txpoll_period = 5; + spin_lock_init(&mb->lock); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, ast2700_mbox_irq, 0, dev_name(dev), mb); + if (ret) + return ret; + + return devm_mbox_controller_register(dev, &mb->mbox); +} + +static const struct ast2700_mbox_data ast2700_dev_data = { + .num_chans = 4, + .msg_size = 0x20, +}; + +static const struct of_device_id ast2700_mbox_of_match[] = { + { .compatible = "aspeed,ast2700-mailbox", .data = &ast2700_dev_data }, + {} +}; +MODULE_DEVICE_TABLE(of, ast2700_mbox_of_match); + +static struct platform_driver ast2700_mbox_driver = { + .driver = { + .name = "ast2700-mailbox", + .of_match_table = ast2700_mbox_of_match, + }, + .probe = ast2700_mbox_probe, +}; +module_platform_driver(ast2700_mbox_driver); + +MODULE_AUTHOR("Jammy Huang <jammy_huang@aspeedtech.com>"); +MODULE_DESCRIPTION("ASPEED AST2700 IPC driver"); +MODULE_LICENSE("GPL"); |