| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * STi Mailbox |
| * |
| * Copyright (C) 2015 ST Microelectronics |
| * |
| * Author: Lee Jones <lee.jones@linaro.org> for ST Microelectronics |
| * |
| * Based on the original driver written by; |
| * Alexandre Torgue, Olivier Lebreton and Loic Pallardy |
| */ |
| |
| #include <linux/err.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/of_device.h> |
| #include <linux/platform_device.h> |
| #include <linux/slab.h> |
| |
| #include "mailbox.h" |
| |
| #define STI_MBOX_INST_MAX 4 /* RAM saving: Max supported instances */ |
| #define STI_MBOX_CHAN_MAX 20 /* RAM saving: Max supported channels */ |
| |
| #define STI_IRQ_VAL_OFFSET 0x04 /* Read interrupt status */ |
| #define STI_IRQ_SET_OFFSET 0x24 /* Generate a Tx channel interrupt */ |
| #define STI_IRQ_CLR_OFFSET 0x44 /* Clear pending Rx interrupts */ |
| #define STI_ENA_VAL_OFFSET 0x64 /* Read enable status */ |
| #define STI_ENA_SET_OFFSET 0x84 /* Enable a channel */ |
| #define STI_ENA_CLR_OFFSET 0xa4 /* Disable a channel */ |
| |
| #define MBOX_BASE(mdev, inst) ((mdev)->base + ((inst) * 4)) |
| |
| /** |
| * struct sti_mbox_device - STi Mailbox device data |
| * |
| * @dev: Device to which it is attached |
| * @mbox: Representation of a communication channel controller |
| * @base: Base address of the register mapping region |
| * @name: Name of the mailbox |
| * @enabled: Local copy of enabled channels |
| * @lock: Mutex protecting enabled status |
| * |
| * An IP Mailbox is currently composed of 4 instances |
| * Each instance is currently composed of 32 channels |
| * This means that we have 128 channels per Mailbox |
| * A channel an be used for TX or RX |
| */ |
| struct sti_mbox_device { |
| struct device *dev; |
| struct mbox_controller *mbox; |
| void __iomem *base; |
| const char *name; |
| u32 enabled[STI_MBOX_INST_MAX]; |
| spinlock_t lock; |
| }; |
| |
| /** |
| * struct sti_mbox_pdata - STi Mailbox platform specific configuration |
| * |
| * @num_inst: Maximum number of instances in one HW Mailbox |
| * @num_chan: Maximum number of channel per instance |
| */ |
| struct sti_mbox_pdata { |
| unsigned int num_inst; |
| unsigned int num_chan; |
| }; |
| |
| /** |
| * struct sti_channel - STi Mailbox allocated channel information |
| * |
| * @mdev: Pointer to parent Mailbox device |
| * @instance: Instance number channel resides in |
| * @channel: Channel number pertaining to this container |
| */ |
| struct sti_channel { |
| struct sti_mbox_device *mdev; |
| unsigned int instance; |
| unsigned int channel; |
| }; |
| |
| static inline bool sti_mbox_channel_is_enabled(struct mbox_chan *chan) |
| { |
| struct sti_channel *chan_info = chan->con_priv; |
| struct sti_mbox_device *mdev = chan_info->mdev; |
| unsigned int instance = chan_info->instance; |
| unsigned int channel = chan_info->channel; |
| |
| return mdev->enabled[instance] & BIT(channel); |
| } |
| |
| static inline |
| struct mbox_chan *sti_mbox_to_channel(struct mbox_controller *mbox, |
| unsigned int instance, |
| unsigned int channel) |
| { |
| struct sti_channel *chan_info; |
| int i; |
| |
| for (i = 0; i < mbox->num_chans; i++) { |
| chan_info = mbox->chans[i].con_priv; |
| if (chan_info && |
| chan_info->instance == instance && |
| chan_info->channel == channel) |
| return &mbox->chans[i]; |
| } |
| |
| dev_err(mbox->dev, |
| "Channel not registered: instance: %d channel: %d\n", |
| instance, channel); |
| |
| return NULL; |
| } |
| |
| static void sti_mbox_enable_channel(struct mbox_chan *chan) |
| { |
| struct sti_channel *chan_info = chan->con_priv; |
| struct sti_mbox_device *mdev = chan_info->mdev; |
| unsigned int instance = chan_info->instance; |
| unsigned int channel = chan_info->channel; |
| unsigned long flags; |
| void __iomem *base = MBOX_BASE(mdev, instance); |
| |
| spin_lock_irqsave(&mdev->lock, flags); |
| mdev->enabled[instance] |= BIT(channel); |
| writel_relaxed(BIT(channel), base + STI_ENA_SET_OFFSET); |
| spin_unlock_irqrestore(&mdev->lock, flags); |
| } |
| |
| static void sti_mbox_disable_channel(struct mbox_chan *chan) |
| { |
| struct sti_channel *chan_info = chan->con_priv; |
| struct sti_mbox_device *mdev = chan_info->mdev; |
| unsigned int instance = chan_info->instance; |
| unsigned int channel = chan_info->channel; |
| unsigned long flags; |
| void __iomem *base = MBOX_BASE(mdev, instance); |
| |
| spin_lock_irqsave(&mdev->lock, flags); |
| mdev->enabled[instance] &= ~BIT(channel); |
| writel_relaxed(BIT(channel), base + STI_ENA_CLR_OFFSET); |
| spin_unlock_irqrestore(&mdev->lock, flags); |
| } |
| |
| static void sti_mbox_clear_irq(struct mbox_chan *chan) |
| { |
| struct sti_channel *chan_info = chan->con_priv; |
| struct sti_mbox_device *mdev = chan_info->mdev; |
| unsigned int instance = chan_info->instance; |
| unsigned int channel = chan_info->channel; |
| void __iomem *base = MBOX_BASE(mdev, instance); |
| |
| writel_relaxed(BIT(channel), base + STI_IRQ_CLR_OFFSET); |
| } |
| |
| static struct mbox_chan *sti_mbox_irq_to_channel(struct sti_mbox_device *mdev, |
| unsigned int instance) |
| { |
| struct mbox_controller *mbox = mdev->mbox; |
| struct mbox_chan *chan = NULL; |
| unsigned int channel; |
| unsigned long bits; |
| void __iomem *base = MBOX_BASE(mdev, instance); |
| |
| bits = readl_relaxed(base + STI_IRQ_VAL_OFFSET); |
| if (!bits) |
| /* No IRQs fired in specified instance */ |
| return NULL; |
| |
| /* An IRQ has fired, find the associated channel */ |
| for (channel = 0; bits; channel++) { |
| if (!test_and_clear_bit(channel, &bits)) |
| continue; |
| |
| chan = sti_mbox_to_channel(mbox, instance, channel); |
| if (chan) { |
| dev_dbg(mbox->dev, |
| "IRQ fired on instance: %d channel: %d\n", |
| instance, channel); |
| break; |
| } |
| } |
| |
| return chan; |
| } |
| |
| static irqreturn_t sti_mbox_thread_handler(int irq, void *data) |
| { |
| struct sti_mbox_device *mdev = data; |
| struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); |
| struct mbox_chan *chan; |
| unsigned int instance; |
| |
| for (instance = 0; instance < pdata->num_inst; instance++) { |
| keep_looking: |
| chan = sti_mbox_irq_to_channel(mdev, instance); |
| if (!chan) |
| continue; |
| |
| mbox_chan_received_data(chan, NULL); |
| sti_mbox_clear_irq(chan); |
| sti_mbox_enable_channel(chan); |
| goto keep_looking; |
| } |
| |
| return IRQ_HANDLED; |
| } |
| |
| static irqreturn_t sti_mbox_irq_handler(int irq, void *data) |
| { |
| struct sti_mbox_device *mdev = data; |
| struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); |
| struct sti_channel *chan_info; |
| struct mbox_chan *chan; |
| unsigned int instance; |
| int ret = IRQ_NONE; |
| |
| for (instance = 0; instance < pdata->num_inst; instance++) { |
| chan = sti_mbox_irq_to_channel(mdev, instance); |
| if (!chan) |
| continue; |
| chan_info = chan->con_priv; |
| |
| if (!sti_mbox_channel_is_enabled(chan)) { |
| dev_warn(mdev->dev, |
| "Unexpected IRQ: %s\n" |
| " instance: %d: channel: %d [enabled: %x]\n", |
| mdev->name, chan_info->instance, |
| chan_info->channel, mdev->enabled[instance]); |
| |
| /* Only handle IRQ if no other valid IRQs were found */ |
| if (ret == IRQ_NONE) |
| ret = IRQ_HANDLED; |
| continue; |
| } |
| |
| sti_mbox_disable_channel(chan); |
| ret = IRQ_WAKE_THREAD; |
| } |
| |
| if (ret == IRQ_NONE) |
| dev_err(mdev->dev, "Spurious IRQ - was a channel requested?\n"); |
| |
| return ret; |
| } |
| |
| static bool sti_mbox_tx_is_ready(struct mbox_chan *chan) |
| { |
| struct sti_channel *chan_info = chan->con_priv; |
| struct sti_mbox_device *mdev = chan_info->mdev; |
| unsigned int instance = chan_info->instance; |
| unsigned int channel = chan_info->channel; |
| void __iomem *base = MBOX_BASE(mdev, instance); |
| |
| if (!(readl_relaxed(base + STI_ENA_VAL_OFFSET) & BIT(channel))) { |
| dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d disabled\n", |
| mdev->name, instance, channel); |
| return false; |
| } |
| |
| if (readl_relaxed(base + STI_IRQ_VAL_OFFSET) & BIT(channel)) { |
| dev_dbg(mdev->dev, "Mbox: %s: inst: %d, chan: %d not ready\n", |
| mdev->name, instance, channel); |
| return false; |
| } |
| |
| return true; |
| } |
| |
| static int sti_mbox_send_data(struct mbox_chan *chan, void *data) |
| { |
| struct sti_channel *chan_info = chan->con_priv; |
| struct sti_mbox_device *mdev = chan_info->mdev; |
| unsigned int instance = chan_info->instance; |
| unsigned int channel = chan_info->channel; |
| void __iomem *base = MBOX_BASE(mdev, instance); |
| |
| /* Send event to co-processor */ |
| writel_relaxed(BIT(channel), base + STI_IRQ_SET_OFFSET); |
| |
| dev_dbg(mdev->dev, |
| "Sent via Mailbox %s: instance: %d channel: %d\n", |
| mdev->name, instance, channel); |
| |
| return 0; |
| } |
| |
| static int sti_mbox_startup_chan(struct mbox_chan *chan) |
| { |
| sti_mbox_clear_irq(chan); |
| sti_mbox_enable_channel(chan); |
| |
| return 0; |
| } |
| |
| static void sti_mbox_shutdown_chan(struct mbox_chan *chan) |
| { |
| struct sti_channel *chan_info = chan->con_priv; |
| struct mbox_controller *mbox = chan_info->mdev->mbox; |
| int i; |
| |
| for (i = 0; i < mbox->num_chans; i++) |
| if (chan == &mbox->chans[i]) |
| break; |
| |
| if (mbox->num_chans == i) { |
| dev_warn(mbox->dev, "Request to free non-existent channel\n"); |
| return; |
| } |
| |
| /* Reset channel */ |
| sti_mbox_disable_channel(chan); |
| sti_mbox_clear_irq(chan); |
| chan->con_priv = NULL; |
| } |
| |
| static struct mbox_chan *sti_mbox_xlate(struct mbox_controller *mbox, |
| const struct of_phandle_args *spec) |
| { |
| struct sti_mbox_device *mdev = dev_get_drvdata(mbox->dev); |
| struct sti_mbox_pdata *pdata = dev_get_platdata(mdev->dev); |
| struct sti_channel *chan_info; |
| struct mbox_chan *chan = NULL; |
| unsigned int instance = spec->args[0]; |
| unsigned int channel = spec->args[1]; |
| int i; |
| |
| /* Bounds checking */ |
| if (instance >= pdata->num_inst || channel >= pdata->num_chan) { |
| dev_err(mbox->dev, |
| "Invalid channel requested instance: %d channel: %d\n", |
| instance, channel); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| for (i = 0; i < mbox->num_chans; i++) { |
| chan_info = mbox->chans[i].con_priv; |
| |
| /* Is requested channel free? */ |
| if (chan_info && |
| mbox->dev == chan_info->mdev->dev && |
| instance == chan_info->instance && |
| channel == chan_info->channel) { |
| |
| dev_err(mbox->dev, "Channel in use\n"); |
| return ERR_PTR(-EBUSY); |
| } |
| |
| /* |
| * Find the first free slot, then continue checking |
| * to see if requested channel is in use |
| */ |
| if (!chan && !chan_info) |
| chan = &mbox->chans[i]; |
| } |
| |
| if (!chan) { |
| dev_err(mbox->dev, "No free channels left\n"); |
| return ERR_PTR(-EBUSY); |
| } |
| |
| chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL); |
| if (!chan_info) |
| return ERR_PTR(-ENOMEM); |
| |
| chan_info->mdev = mdev; |
| chan_info->instance = instance; |
| chan_info->channel = channel; |
| |
| chan->con_priv = chan_info; |
| |
| dev_info(mbox->dev, |
| "Mbox: %s: Created channel: instance: %d channel: %d\n", |
| mdev->name, instance, channel); |
| |
| return chan; |
| } |
| |
| static const struct mbox_chan_ops sti_mbox_ops = { |
| .startup = sti_mbox_startup_chan, |
| .shutdown = sti_mbox_shutdown_chan, |
| .send_data = sti_mbox_send_data, |
| .last_tx_done = sti_mbox_tx_is_ready, |
| }; |
| |
| static const struct sti_mbox_pdata mbox_stih407_pdata = { |
| .num_inst = 4, |
| .num_chan = 32, |
| }; |
| |
| static const struct of_device_id sti_mailbox_match[] = { |
| { |
| .compatible = "st,stih407-mailbox", |
| .data = (void *)&mbox_stih407_pdata |
| }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, sti_mailbox_match); |
| |
| static int sti_mbox_probe(struct platform_device *pdev) |
| { |
| const struct of_device_id *match; |
| struct mbox_controller *mbox; |
| struct sti_mbox_device *mdev; |
| struct device_node *np = pdev->dev.of_node; |
| struct mbox_chan *chans; |
| struct resource *res; |
| int irq; |
| int ret; |
| |
| match = of_match_device(sti_mailbox_match, &pdev->dev); |
| if (!match) { |
| dev_err(&pdev->dev, "No configuration found\n"); |
| return -ENODEV; |
| } |
| pdev->dev.platform_data = (struct sti_mbox_pdata *) match->data; |
| |
| mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL); |
| if (!mdev) |
| return -ENOMEM; |
| |
| platform_set_drvdata(pdev, mdev); |
| |
| res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| mdev->base = devm_ioremap_resource(&pdev->dev, res); |
| if (IS_ERR(mdev->base)) |
| return PTR_ERR(mdev->base); |
| |
| ret = of_property_read_string(np, "mbox-name", &mdev->name); |
| if (ret) |
| mdev->name = np->full_name; |
| |
| mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL); |
| if (!mbox) |
| return -ENOMEM; |
| |
| chans = devm_kcalloc(&pdev->dev, |
| STI_MBOX_CHAN_MAX, sizeof(*chans), GFP_KERNEL); |
| if (!chans) |
| return -ENOMEM; |
| |
| mdev->dev = &pdev->dev; |
| mdev->mbox = mbox; |
| |
| spin_lock_init(&mdev->lock); |
| |
| /* STi Mailbox does not have a Tx-Done or Tx-Ready IRQ */ |
| mbox->txdone_irq = false; |
| mbox->txdone_poll = true; |
| mbox->txpoll_period = 100; |
| mbox->ops = &sti_mbox_ops; |
| mbox->dev = mdev->dev; |
| mbox->of_xlate = sti_mbox_xlate; |
| mbox->chans = chans; |
| mbox->num_chans = STI_MBOX_CHAN_MAX; |
| |
| ret = devm_mbox_controller_register(&pdev->dev, mbox); |
| if (ret) |
| return ret; |
| |
| /* It's okay for Tx Mailboxes to not supply IRQs */ |
| irq = platform_get_irq(pdev, 0); |
| if (irq < 0) { |
| dev_info(&pdev->dev, |
| "%s: Registered Tx only Mailbox\n", mdev->name); |
| return 0; |
| } |
| |
| ret = devm_request_threaded_irq(&pdev->dev, irq, |
| sti_mbox_irq_handler, |
| sti_mbox_thread_handler, |
| IRQF_ONESHOT, mdev->name, mdev); |
| if (ret) { |
| dev_err(&pdev->dev, "Can't claim IRQ %d\n", irq); |
| return -EINVAL; |
| } |
| |
| dev_info(&pdev->dev, "%s: Registered Tx/Rx Mailbox\n", mdev->name); |
| |
| return 0; |
| } |
| |
| static struct platform_driver sti_mbox_driver = { |
| .probe = sti_mbox_probe, |
| .driver = { |
| .name = "sti-mailbox", |
| .of_match_table = sti_mailbox_match, |
| }, |
| }; |
| module_platform_driver(sti_mbox_driver); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("STMicroelectronics Mailbox Controller"); |
| MODULE_AUTHOR("Lee Jones <lee.jones@linaro.org"); |
| MODULE_ALIAS("platform:mailbox-sti"); |