diff options
Diffstat (limited to 'drivers/mailbox/armada-37xx-rwtm-mailbox.c')
| -rw-r--r-- | drivers/mailbox/armada-37xx-rwtm-mailbox.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/drivers/mailbox/armada-37xx-rwtm-mailbox.c b/drivers/mailbox/armada-37xx-rwtm-mailbox.c new file mode 100644 index 000000000..456a117a6 --- /dev/null +++ b/drivers/mailbox/armada-37xx-rwtm-mailbox.c @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * rWTM BIU Mailbox driver for Armada 37xx + * + * Author: Marek Behún <kabel@kernel.org> + */ + +#include <linux/device.h> +#include <linux/interrupt.h> +#include <linux/io.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/armada-37xx-rwtm-mailbox.h> + +#define DRIVER_NAME "armada-37xx-rwtm-mailbox" + +/* relative to rWTM BIU Mailbox Registers */ +#define RWTM_MBOX_PARAM(i) (0x0 + ((i) << 2)) +#define RWTM_MBOX_COMMAND 0x40 +#define RWTM_MBOX_RETURN_STATUS 0x80 +#define RWTM_MBOX_STATUS(i) (0x84 + ((i) << 2)) +#define RWTM_MBOX_FIFO_STATUS 0xc4 +#define FIFO_STS_RDY 0x100 +#define FIFO_STS_CNTR_MASK 0x7 +#define FIFO_STS_CNTR_MAX 4 + +#define RWTM_HOST_INT_RESET 0xc8 +#define RWTM_HOST_INT_MASK 0xcc +#define SP_CMD_COMPLETE BIT(0) +#define SP_CMD_QUEUE_FULL_ACCESS BIT(17) +#define SP_CMD_QUEUE_FULL BIT(18) + +struct a37xx_mbox { + struct device *dev; + struct mbox_controller controller; + void __iomem *base; + int irq; +}; + +static void a37xx_mbox_receive(struct mbox_chan *chan) +{ + struct a37xx_mbox *mbox = chan->con_priv; + struct armada_37xx_rwtm_rx_msg rx_msg; + int i; + + rx_msg.retval = readl(mbox->base + RWTM_MBOX_RETURN_STATUS); + for (i = 0; i < 16; ++i) + rx_msg.status[i] = readl(mbox->base + RWTM_MBOX_STATUS(i)); + + mbox_chan_received_data(chan, &rx_msg); +} + +static irqreturn_t a37xx_mbox_irq_handler(int irq, void *data) +{ + struct mbox_chan *chan = data; + struct a37xx_mbox *mbox = chan->con_priv; + u32 reg; + + reg = readl(mbox->base + RWTM_HOST_INT_RESET); + + if (reg & SP_CMD_COMPLETE) + a37xx_mbox_receive(chan); + + if (reg & (SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL)) + dev_err(mbox->dev, "Secure processor command queue full\n"); + + writel(reg, mbox->base + RWTM_HOST_INT_RESET); + if (reg) + mbox_chan_txdone(chan, 0); + + return reg ? IRQ_HANDLED : IRQ_NONE; +} + +static int a37xx_mbox_send_data(struct mbox_chan *chan, void *data) +{ + struct a37xx_mbox *mbox = chan->con_priv; + struct armada_37xx_rwtm_tx_msg *msg = data; + int i; + u32 reg; + + if (!data) + return -EINVAL; + + reg = readl(mbox->base + RWTM_MBOX_FIFO_STATUS); + if (!(reg & FIFO_STS_RDY)) + dev_warn(mbox->dev, "Secure processor not ready\n"); + + if ((reg & FIFO_STS_CNTR_MASK) >= FIFO_STS_CNTR_MAX) { + dev_err(mbox->dev, "Secure processor command queue full\n"); + return -EBUSY; + } + + for (i = 0; i < 16; ++i) + writel(msg->args[i], mbox->base + RWTM_MBOX_PARAM(i)); + writel(msg->command, mbox->base + RWTM_MBOX_COMMAND); + + return 0; +} + +static int a37xx_mbox_startup(struct mbox_chan *chan) +{ + struct a37xx_mbox *mbox = chan->con_priv; + u32 reg; + int ret; + + ret = devm_request_irq(mbox->dev, mbox->irq, a37xx_mbox_irq_handler, 0, + DRIVER_NAME, chan); + if (ret < 0) { + dev_err(mbox->dev, "Cannot request irq\n"); + return ret; + } + + /* enable IRQ generation */ + reg = readl(mbox->base + RWTM_HOST_INT_MASK); + reg &= ~(SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL); + writel(reg, mbox->base + RWTM_HOST_INT_MASK); + + return 0; +} + +static void a37xx_mbox_shutdown(struct mbox_chan *chan) +{ + u32 reg; + struct a37xx_mbox *mbox = chan->con_priv; + + /* disable interrupt generation */ + reg = readl(mbox->base + RWTM_HOST_INT_MASK); + reg |= SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL; + writel(reg, mbox->base + RWTM_HOST_INT_MASK); + + devm_free_irq(mbox->dev, mbox->irq, chan); +} + +static const struct mbox_chan_ops a37xx_mbox_ops = { + .send_data = a37xx_mbox_send_data, + .startup = a37xx_mbox_startup, + .shutdown = a37xx_mbox_shutdown, +}; + +static int armada_37xx_mbox_probe(struct platform_device *pdev) +{ + struct a37xx_mbox *mbox; + struct mbox_chan *chans; + int ret; + + mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL); + if (!mbox) + return -ENOMEM; + + /* Allocated one channel */ + chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL); + if (!chans) + return -ENOMEM; + + mbox->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(mbox->base)) + return PTR_ERR(mbox->base); + + mbox->irq = platform_get_irq(pdev, 0); + if (mbox->irq < 0) + return mbox->irq; + + mbox->dev = &pdev->dev; + + /* Hardware supports only one channel. */ + chans[0].con_priv = mbox; + mbox->controller.dev = mbox->dev; + mbox->controller.num_chans = 1; + mbox->controller.chans = chans; + mbox->controller.ops = &a37xx_mbox_ops; + mbox->controller.txdone_irq = true; + + ret = devm_mbox_controller_register(mbox->dev, &mbox->controller); + if (ret) { + dev_err(&pdev->dev, "Could not register mailbox controller\n"); + return ret; + } + + platform_set_drvdata(pdev, mbox); + return ret; +} + + +static const struct of_device_id armada_37xx_mbox_match[] = { + { .compatible = "marvell,armada-3700-rwtm-mailbox" }, + { }, +}; + +MODULE_DEVICE_TABLE(of, armada_37xx_mbox_match); + +static struct platform_driver armada_37xx_mbox_driver = { + .probe = armada_37xx_mbox_probe, + .driver = { + .name = DRIVER_NAME, + .of_match_table = armada_37xx_mbox_match, + }, +}; + +module_platform_driver(armada_37xx_mbox_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("rWTM BIU Mailbox driver for Armada 37xx"); +MODULE_AUTHOR("Marek Behun <kabel@kernel.org>"); |