1 // SPDX-License-Identifier: GPL-2.0-only
3  * Copyright (C) 2013-2015 Fujitsu Semiconductor Ltd.
5  * Based on ARM MHU driver by Jassi Brar <jaswinder.singh@linaro.org>
28 #define MHU_CHANS	3	/* Secure, Non-Secure High and Low Priority */
46  * struct mhu_db_channel - ARM MHU Mailbox allocated channel information
48  * @mhu: Pointer to parent mailbox device
49  * @pchan: Physical channel within which this doorbell resides in
50  * @doorbell: doorbell number pertaining to this channel
53 	struct arm_mhu *mhu;  member
55 	unsigned int doorbell;  member
60 		       unsigned int doorbell)  in mhu_db_mbox_to_channel()  argument
65 	for (i = 0; i < mbox->num_chans; i++) {  in mhu_db_mbox_to_channel()
66 		chan_info = mbox->chans[i].con_priv;  in mhu_db_mbox_to_channel()
67 		if (chan_info && chan_info->pchan == pchan &&  in mhu_db_mbox_to_channel()
68 		    chan_info->doorbell == doorbell)  in mhu_db_mbox_to_channel()
69 			return &mbox->chans[i];  in mhu_db_mbox_to_channel()
77 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_mbox_clear_irq()
78 	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].rx_reg;  in mhu_db_mbox_clear_irq()
80 	writel_relaxed(BIT(chan_info->doorbell), base + INTR_CLR_OFS);  in mhu_db_mbox_clear_irq()
83 static unsigned int mhu_db_mbox_irq_to_pchan_num(struct arm_mhu *mhu, int irq)  in mhu_db_mbox_irq_to_pchan_num()  argument
88 		if (mhu->mlink[pchan].irq == irq)  in mhu_db_mbox_irq_to_pchan_num()
94 mhu_db_mbox_irq_to_channel(struct arm_mhu *mhu, unsigned int pchan)  in mhu_db_mbox_irq_to_channel()  argument
97 	unsigned int doorbell;  in mhu_db_mbox_irq_to_channel()  local
99 	struct mbox_controller *mbox = &mhu->mbox;  in mhu_db_mbox_irq_to_channel()
100 	void __iomem *base = mhu->mlink[pchan].rx_reg;  in mhu_db_mbox_irq_to_channel()
108 	for (doorbell = 0; bits; doorbell++) {  in mhu_db_mbox_irq_to_channel()
109 		if (!test_and_clear_bit(doorbell, &bits))  in mhu_db_mbox_irq_to_channel()
112 		chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);  in mhu_db_mbox_irq_to_channel()
115 		dev_err(mbox->dev,  in mhu_db_mbox_irq_to_channel()
116 			"Channel not registered: pchan: %d doorbell: %d\n",  in mhu_db_mbox_irq_to_channel()
117 			pchan, doorbell);  in mhu_db_mbox_irq_to_channel()
126 	struct arm_mhu *mhu = data;  in mhu_db_mbox_rx_handler()  local
127 	unsigned int pchan = mhu_db_mbox_irq_to_pchan_num(mhu, irq);  in mhu_db_mbox_rx_handler()
129 	while (NULL != (chan = mhu_db_mbox_irq_to_channel(mhu, pchan))) {  in mhu_db_mbox_rx_handler()
139 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_last_tx_done()
140 	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;  in mhu_db_last_tx_done()
142 	if (readl_relaxed(base + INTR_STAT_OFS) & BIT(chan_info->doorbell))  in mhu_db_last_tx_done()
150 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_send_data()
151 	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;  in mhu_db_send_data()
153 	/* Send event to co-processor */  in mhu_db_send_data()
154 	writel_relaxed(BIT(chan_info->doorbell), base + INTR_SET_OFS);  in mhu_db_send_data()
167 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_shutdown()
168 	struct mbox_controller *mbox = &chan_info->mhu->mbox;  in mhu_db_shutdown()
171 	for (i = 0; i < mbox->num_chans; i++)  in mhu_db_shutdown()
172 		if (chan == &mbox->chans[i])  in mhu_db_shutdown()
175 	if (mbox->num_chans == i) {  in mhu_db_shutdown()
176 		dev_warn(mbox->dev, "Request to free non-existent channel\n");  in mhu_db_shutdown()
182 	devm_kfree(mbox->dev, chan->con_priv);  in mhu_db_shutdown()
183 	chan->con_priv = NULL;  in mhu_db_shutdown()
189 	struct arm_mhu *mhu = dev_get_drvdata(mbox->dev);  in mhu_db_mbox_xlate()  local
192 	unsigned int pchan = spec->args[0];  in mhu_db_mbox_xlate()
193 	unsigned int doorbell = spec->args[1];  in mhu_db_mbox_xlate()  local
197 	if (pchan >= MHU_CHANS || doorbell >= MHU_NUM_DOORBELLS) {  in mhu_db_mbox_xlate()
198 		dev_err(mbox->dev,  in mhu_db_mbox_xlate()
199 			"Invalid channel requested pchan: %d doorbell: %d\n",  in mhu_db_mbox_xlate()
200 			pchan, doorbell);  in mhu_db_mbox_xlate()
201 		return ERR_PTR(-EINVAL);  in mhu_db_mbox_xlate()
205 	chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);  in mhu_db_mbox_xlate()
207 		dev_err(mbox->dev, "Channel in use: pchan: %d doorbell: %d\n",  in mhu_db_mbox_xlate()
208 			pchan, doorbell);  in mhu_db_mbox_xlate()
209 		return ERR_PTR(-EBUSY);  in mhu_db_mbox_xlate()
213 	for (i = 0; i < mbox->num_chans; i++)  in mhu_db_mbox_xlate()
214 		if (!mbox->chans[i].con_priv)  in mhu_db_mbox_xlate()
217 	if (mbox->num_chans == i) {  in mhu_db_mbox_xlate()
218 		dev_err(mbox->dev, "No free channels left\n");  in mhu_db_mbox_xlate()
219 		return ERR_PTR(-EBUSY);  in mhu_db_mbox_xlate()
222 	chan = &mbox->chans[i];  in mhu_db_mbox_xlate()
224 	chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);  in mhu_db_mbox_xlate()
226 		return ERR_PTR(-ENOMEM);  in mhu_db_mbox_xlate()
228 	chan_info->mhu = mhu;  in mhu_db_mbox_xlate()
229 	chan_info->pchan = pchan;  in mhu_db_mbox_xlate()
230 	chan_info->doorbell = doorbell;  in mhu_db_mbox_xlate()
232 	chan->con_priv = chan_info;  in mhu_db_mbox_xlate()
234 	dev_dbg(mbox->dev, "mbox: created channel phys: %d doorbell: %d\n",  in mhu_db_mbox_xlate()
235 		pchan, doorbell);  in mhu_db_mbox_xlate()
251 	struct arm_mhu *mhu;  in mhu_db_probe()  local
253 	struct device *dev = &adev->dev;  in mhu_db_probe()
254 	struct device_node *np = dev->of_node;  in mhu_db_probe()
259 	if (!of_device_is_compatible(np, "arm,mhu-doorbell"))  in mhu_db_probe()
260 		return -ENODEV;  in mhu_db_probe()
262 	err = of_property_read_u32(np, "#mbox-cells", &cell_count);  in mhu_db_probe()
264 		dev_err(dev, "failed to read #mbox-cells in '%pOF'\n", np);  in mhu_db_probe()
271 		dev_err(dev, "incorrect value of #mbox-cells in '%pOF'\n", np);  in mhu_db_probe()
272 		return -EINVAL;  in mhu_db_probe()
275 	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);  in mhu_db_probe()
276 	if (!mhu)  in mhu_db_probe()
277 		return -ENOMEM;  in mhu_db_probe()
279 	mhu->base = devm_ioremap_resource(dev, &adev->res);  in mhu_db_probe()
280 	if (IS_ERR(mhu->base))  in mhu_db_probe()
281 		return PTR_ERR(mhu->base);  in mhu_db_probe()
285 		return -ENOMEM;  in mhu_db_probe()
287 	mhu->dev = dev;  in mhu_db_probe()
288 	mhu->mbox.dev = dev;  in mhu_db_probe()
289 	mhu->mbox.chans = chans;  in mhu_db_probe()
290 	mhu->mbox.num_chans = max_chans;  in mhu_db_probe()
291 	mhu->mbox.txdone_irq = false;  in mhu_db_probe()
292 	mhu->mbox.txdone_poll = true;  in mhu_db_probe()
293 	mhu->mbox.txpoll_period = 1;  in mhu_db_probe()
295 	mhu->mbox.of_xlate = mhu_db_mbox_xlate;  in mhu_db_probe()
296 	amba_set_drvdata(adev, mhu);  in mhu_db_probe()
298 	mhu->mbox.ops = &mhu_db_ops;  in mhu_db_probe()
300 	err = devm_mbox_controller_register(dev, &mhu->mbox);  in mhu_db_probe()
307 		int irq = mhu->mlink[i].irq = adev->irq[i];  in mhu_db_probe()
314 		mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];  in mhu_db_probe()
315 		mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;  in mhu_db_probe()
319 						IRQF_ONESHOT, "mhu_db_link", mhu);  in mhu_db_probe()
322 			mbox_controller_unregister(&mhu->mbox);  in mhu_db_probe()
327 	dev_info(dev, "ARM MHU Doorbell mailbox registered\n");  in mhu_db_probe()
342 		.name	= "mhu-doorbell",
350 MODULE_DESCRIPTION("ARM MHU Doorbell Driver");