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354 lines
8.3 KiB
354 lines
8.3 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd. |
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* Copyright (C) 2015 Linaro Ltd. |
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* Based on ARM MHU driver by Jassi Brar <[email protected]> |
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* Copyright (C) 2020 ARM Ltd. |
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*/ |
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#include <linux/amba/bus.h> |
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#include <linux/device.h> |
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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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#define INTR_STAT_OFS 0x0 |
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#define INTR_SET_OFS 0x8 |
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#define INTR_CLR_OFS 0x10 |
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#define MHU_LP_OFFSET 0x0 |
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#define MHU_HP_OFFSET 0x20 |
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#define MHU_SEC_OFFSET 0x200 |
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#define TX_REG_OFFSET 0x100 |
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#define MHU_CHANS 3 /* Secure, Non-Secure High and Low Priority */ |
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#define MHU_CHAN_MAX 20 /* Max channels to save on unused RAM */ |
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#define MHU_NUM_DOORBELLS 32 |
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struct mhu_db_link { |
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unsigned int irq; |
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void __iomem *tx_reg; |
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void __iomem *rx_reg; |
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}; |
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struct arm_mhu { |
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void __iomem *base; |
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struct mhu_db_link mlink[MHU_CHANS]; |
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struct mbox_controller mbox; |
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struct device *dev; |
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}; |
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/** |
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* ARM MHU Mailbox allocated channel information |
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* |
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* @mhu: Pointer to parent mailbox device |
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* @pchan: Physical channel within which this doorbell resides in |
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* @doorbell: doorbell number pertaining to this channel |
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*/ |
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struct mhu_db_channel { |
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struct arm_mhu *mhu; |
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unsigned int pchan; |
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unsigned int doorbell; |
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}; |
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static inline struct mbox_chan * |
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mhu_db_mbox_to_channel(struct mbox_controller *mbox, unsigned int pchan, |
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unsigned int doorbell) |
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{ |
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int i; |
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struct mhu_db_channel *chan_info; |
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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 && chan_info->pchan == pchan && |
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chan_info->doorbell == doorbell) |
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return &mbox->chans[i]; |
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} |
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return NULL; |
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} |
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static void mhu_db_mbox_clear_irq(struct mbox_chan *chan) |
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{ |
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struct mhu_db_channel *chan_info = chan->con_priv; |
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void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].rx_reg; |
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writel_relaxed(BIT(chan_info->doorbell), base + INTR_CLR_OFS); |
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} |
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static unsigned int mhu_db_mbox_irq_to_pchan_num(struct arm_mhu *mhu, int irq) |
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{ |
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unsigned int pchan; |
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for (pchan = 0; pchan < MHU_CHANS; pchan++) |
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if (mhu->mlink[pchan].irq == irq) |
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break; |
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return pchan; |
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} |
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static struct mbox_chan * |
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mhu_db_mbox_irq_to_channel(struct arm_mhu *mhu, unsigned int pchan) |
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{ |
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unsigned long bits; |
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unsigned int doorbell; |
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struct mbox_chan *chan = NULL; |
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struct mbox_controller *mbox = &mhu->mbox; |
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void __iomem *base = mhu->mlink[pchan].rx_reg; |
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bits = readl_relaxed(base + INTR_STAT_OFS); |
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if (!bits) |
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/* No IRQs fired in specified physical channel */ |
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return NULL; |
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/* An IRQ has fired, find the associated channel */ |
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for (doorbell = 0; bits; doorbell++) { |
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if (!test_and_clear_bit(doorbell, &bits)) |
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continue; |
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chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell); |
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if (chan) |
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break; |
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dev_err(mbox->dev, |
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"Channel not registered: pchan: %d doorbell: %d\n", |
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pchan, doorbell); |
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} |
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return chan; |
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} |
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static irqreturn_t mhu_db_mbox_rx_handler(int irq, void *data) |
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{ |
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struct mbox_chan *chan; |
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struct arm_mhu *mhu = data; |
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unsigned int pchan = mhu_db_mbox_irq_to_pchan_num(mhu, irq); |
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while (NULL != (chan = mhu_db_mbox_irq_to_channel(mhu, pchan))) { |
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mbox_chan_received_data(chan, NULL); |
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mhu_db_mbox_clear_irq(chan); |
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} |
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return IRQ_HANDLED; |
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} |
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static bool mhu_db_last_tx_done(struct mbox_chan *chan) |
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{ |
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struct mhu_db_channel *chan_info = chan->con_priv; |
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void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg; |
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if (readl_relaxed(base + INTR_STAT_OFS) & BIT(chan_info->doorbell)) |
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return false; |
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return true; |
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} |
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static int mhu_db_send_data(struct mbox_chan *chan, void *data) |
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{ |
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struct mhu_db_channel *chan_info = chan->con_priv; |
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void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg; |
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/* Send event to co-processor */ |
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writel_relaxed(BIT(chan_info->doorbell), base + INTR_SET_OFS); |
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return 0; |
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} |
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static int mhu_db_startup(struct mbox_chan *chan) |
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{ |
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mhu_db_mbox_clear_irq(chan); |
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return 0; |
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} |
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static void mhu_db_shutdown(struct mbox_chan *chan) |
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{ |
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struct mhu_db_channel *chan_info = chan->con_priv; |
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struct mbox_controller *mbox = &chan_info->mhu->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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mhu_db_mbox_clear_irq(chan); |
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devm_kfree(mbox->dev, chan->con_priv); |
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chan->con_priv = NULL; |
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} |
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static struct mbox_chan *mhu_db_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 arm_mhu *mhu = dev_get_drvdata(mbox->dev); |
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struct mhu_db_channel *chan_info; |
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struct mbox_chan *chan; |
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unsigned int pchan = spec->args[0]; |
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unsigned int doorbell = spec->args[1]; |
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int i; |
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/* Bounds checking */ |
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if (pchan >= MHU_CHANS || doorbell >= MHU_NUM_DOORBELLS) { |
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dev_err(mbox->dev, |
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"Invalid channel requested pchan: %d doorbell: %d\n", |
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pchan, doorbell); |
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return ERR_PTR(-EINVAL); |
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} |
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/* Is requested channel free? */ |
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chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell); |
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if (chan) { |
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dev_err(mbox->dev, "Channel in use: pchan: %d doorbell: %d\n", |
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pchan, doorbell); |
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return ERR_PTR(-EBUSY); |
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} |
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/* Find the first free slot */ |
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for (i = 0; i < mbox->num_chans; i++) |
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if (!mbox->chans[i].con_priv) |
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break; |
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if (mbox->num_chans == i) { |
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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 = &mbox->chans[i]; |
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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->mhu = mhu; |
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chan_info->pchan = pchan; |
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chan_info->doorbell = doorbell; |
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chan->con_priv = chan_info; |
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dev_dbg(mbox->dev, "mbox: created channel phys: %d doorbell: %d\n", |
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pchan, doorbell); |
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return chan; |
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} |
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static const struct mbox_chan_ops mhu_db_ops = { |
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.send_data = mhu_db_send_data, |
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.startup = mhu_db_startup, |
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.shutdown = mhu_db_shutdown, |
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.last_tx_done = mhu_db_last_tx_done, |
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}; |
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static int mhu_db_probe(struct amba_device *adev, const struct amba_id *id) |
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{ |
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u32 cell_count; |
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int i, err, max_chans; |
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struct arm_mhu *mhu; |
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struct mbox_chan *chans; |
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struct device *dev = &adev->dev; |
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struct device_node *np = dev->of_node; |
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int mhu_reg[MHU_CHANS] = { |
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MHU_LP_OFFSET, MHU_HP_OFFSET, MHU_SEC_OFFSET, |
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}; |
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if (!of_device_is_compatible(np, "arm,mhu-doorbell")) |
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return -ENODEV; |
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err = of_property_read_u32(np, "#mbox-cells", &cell_count); |
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if (err) { |
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dev_err(dev, "failed to read #mbox-cells in '%pOF'\n", np); |
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return err; |
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} |
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if (cell_count == 2) { |
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max_chans = MHU_CHAN_MAX; |
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} else { |
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dev_err(dev, "incorrect value of #mbox-cells in '%pOF'\n", np); |
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return -EINVAL; |
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} |
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mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL); |
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if (!mhu) |
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return -ENOMEM; |
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mhu->base = devm_ioremap_resource(dev, &adev->res); |
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if (IS_ERR(mhu->base)) { |
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dev_err(dev, "ioremap failed\n"); |
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return PTR_ERR(mhu->base); |
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} |
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chans = devm_kcalloc(dev, max_chans, sizeof(*chans), GFP_KERNEL); |
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if (!chans) |
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return -ENOMEM; |
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mhu->dev = dev; |
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mhu->mbox.dev = dev; |
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mhu->mbox.chans = chans; |
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mhu->mbox.num_chans = max_chans; |
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mhu->mbox.txdone_irq = false; |
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mhu->mbox.txdone_poll = true; |
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mhu->mbox.txpoll_period = 1; |
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mhu->mbox.of_xlate = mhu_db_mbox_xlate; |
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amba_set_drvdata(adev, mhu); |
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mhu->mbox.ops = &mhu_db_ops; |
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err = devm_mbox_controller_register(dev, &mhu->mbox); |
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if (err) { |
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dev_err(dev, "Failed to register mailboxes %d\n", err); |
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return err; |
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} |
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for (i = 0; i < MHU_CHANS; i++) { |
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int irq = mhu->mlink[i].irq = adev->irq[i]; |
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if (irq <= 0) { |
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dev_dbg(dev, "No IRQ found for Channel %d\n", i); |
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continue; |
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} |
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mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i]; |
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mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET; |
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err = devm_request_threaded_irq(dev, irq, NULL, |
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mhu_db_mbox_rx_handler, |
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IRQF_ONESHOT, "mhu_db_link", mhu); |
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if (err) { |
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dev_err(dev, "Can't claim IRQ %d\n", irq); |
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mbox_controller_unregister(&mhu->mbox); |
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return err; |
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} |
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} |
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dev_info(dev, "ARM MHU Doorbell mailbox registered\n"); |
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return 0; |
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} |
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static struct amba_id mhu_ids[] = { |
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{ |
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.id = 0x1bb098, |
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.mask = 0xffffff, |
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}, |
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{ 0, 0 }, |
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}; |
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MODULE_DEVICE_TABLE(amba, mhu_ids); |
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static struct amba_driver arm_mhu_db_driver = { |
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.drv = { |
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.name = "mhu-doorbell", |
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}, |
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.id_table = mhu_ids, |
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.probe = mhu_db_probe, |
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}; |
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module_amba_driver(arm_mhu_db_driver); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_DESCRIPTION("ARM MHU Doorbell Driver"); |
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MODULE_AUTHOR("Sudeep Holla <[email protected]>");
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