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