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>
29 #define MHU_CHANS	3	/* Secure, Non-Secure High and Low Priority */
47  * struct mhu_db_channel - ARM MHU Mailbox allocated channel information
49  * @mhu: Pointer to parent mailbox device
50  * @pchan: Physical channel within which this doorbell resides in
51  * @doorbell: doorbell number pertaining to this channel
54 	struct arm_mhu *mhu;  member
56 	unsigned int doorbell;  member
61 		       unsigned int doorbell)  in mhu_db_mbox_to_channel()  argument
66 	for (i = 0; i < mbox->num_chans; i++) {  in mhu_db_mbox_to_channel()
67 		chan_info = mbox->chans[i].con_priv;  in mhu_db_mbox_to_channel()
68 		if (chan_info && chan_info->pchan == pchan &&  in mhu_db_mbox_to_channel()
69 		    chan_info->doorbell == doorbell)  in mhu_db_mbox_to_channel()
70 			return &mbox->chans[i];  in mhu_db_mbox_to_channel()
78 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_mbox_clear_irq()
79 	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].rx_reg;  in mhu_db_mbox_clear_irq()
81 	writel_relaxed(BIT(chan_info->doorbell), base + INTR_CLR_OFS);  in mhu_db_mbox_clear_irq()
84 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
89 		if (mhu->mlink[pchan].irq == irq)  in mhu_db_mbox_irq_to_pchan_num()
95 mhu_db_mbox_irq_to_channel(struct arm_mhu *mhu, unsigned int pchan)  in mhu_db_mbox_irq_to_channel()  argument
98 	unsigned int doorbell;  in mhu_db_mbox_irq_to_channel()  local
100 	struct mbox_controller *mbox = &mhu->mbox;  in mhu_db_mbox_irq_to_channel()
101 	void __iomem *base = mhu->mlink[pchan].rx_reg;  in mhu_db_mbox_irq_to_channel()
109 	for (doorbell = 0; bits; doorbell++) {  in mhu_db_mbox_irq_to_channel()
110 		if (!test_and_clear_bit(doorbell, &bits))  in mhu_db_mbox_irq_to_channel()
113 		chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);  in mhu_db_mbox_irq_to_channel()
116 		dev_err(mbox->dev,  in mhu_db_mbox_irq_to_channel()
117 			"Channel not registered: pchan: %d doorbell: %d\n",  in mhu_db_mbox_irq_to_channel()
118 			pchan, doorbell);  in mhu_db_mbox_irq_to_channel()
127 	struct arm_mhu *mhu = data;  in mhu_db_mbox_rx_handler()  local
128 	unsigned int pchan = mhu_db_mbox_irq_to_pchan_num(mhu, irq);  in mhu_db_mbox_rx_handler()
130 	while (NULL != (chan = mhu_db_mbox_irq_to_channel(mhu, pchan))) {  in mhu_db_mbox_rx_handler()
140 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_last_tx_done()
141 	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;  in mhu_db_last_tx_done()
143 	if (readl_relaxed(base + INTR_STAT_OFS) & BIT(chan_info->doorbell))  in mhu_db_last_tx_done()
151 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_send_data()
152 	void __iomem *base = chan_info->mhu->mlink[chan_info->pchan].tx_reg;  in mhu_db_send_data()
154 	/* Send event to co-processor */  in mhu_db_send_data()
155 	writel_relaxed(BIT(chan_info->doorbell), base + INTR_SET_OFS);  in mhu_db_send_data()
168 	struct mhu_db_channel *chan_info = chan->con_priv;  in mhu_db_shutdown()
169 	struct mbox_controller *mbox = &chan_info->mhu->mbox;  in mhu_db_shutdown()
172 	for (i = 0; i < mbox->num_chans; i++)  in mhu_db_shutdown()
173 		if (chan == &mbox->chans[i])  in mhu_db_shutdown()
176 	if (mbox->num_chans == i) {  in mhu_db_shutdown()
177 		dev_warn(mbox->dev, "Request to free non-existent channel\n");  in mhu_db_shutdown()
183 	devm_kfree(mbox->dev, chan->con_priv);  in mhu_db_shutdown()
184 	chan->con_priv = NULL;  in mhu_db_shutdown()
190 	struct arm_mhu *mhu = dev_get_drvdata(mbox->dev);  in mhu_db_mbox_xlate()  local
193 	unsigned int pchan = spec->args[0];  in mhu_db_mbox_xlate()
194 	unsigned int doorbell = spec->args[1];  in mhu_db_mbox_xlate()  local
198 	if (pchan >= MHU_CHANS || doorbell >= MHU_NUM_DOORBELLS) {  in mhu_db_mbox_xlate()
199 		dev_err(mbox->dev,  in mhu_db_mbox_xlate()
200 			"Invalid channel requested pchan: %d doorbell: %d\n",  in mhu_db_mbox_xlate()
201 			pchan, doorbell);  in mhu_db_mbox_xlate()
202 		return ERR_PTR(-EINVAL);  in mhu_db_mbox_xlate()
206 	chan = mhu_db_mbox_to_channel(mbox, pchan, doorbell);  in mhu_db_mbox_xlate()
208 		dev_err(mbox->dev, "Channel in use: pchan: %d doorbell: %d\n",  in mhu_db_mbox_xlate()
209 			pchan, doorbell);  in mhu_db_mbox_xlate()
210 		return ERR_PTR(-EBUSY);  in mhu_db_mbox_xlate()
214 	for (i = 0; i < mbox->num_chans; i++)  in mhu_db_mbox_xlate()
215 		if (!mbox->chans[i].con_priv)  in mhu_db_mbox_xlate()
218 	if (mbox->num_chans == i) {  in mhu_db_mbox_xlate()
219 		dev_err(mbox->dev, "No free channels left\n");  in mhu_db_mbox_xlate()
220 		return ERR_PTR(-EBUSY);  in mhu_db_mbox_xlate()
223 	chan = &mbox->chans[i];  in mhu_db_mbox_xlate()
225 	chan_info = devm_kzalloc(mbox->dev, sizeof(*chan_info), GFP_KERNEL);  in mhu_db_mbox_xlate()
227 		return ERR_PTR(-ENOMEM);  in mhu_db_mbox_xlate()
229 	chan_info->mhu = mhu;  in mhu_db_mbox_xlate()
230 	chan_info->pchan = pchan;  in mhu_db_mbox_xlate()
231 	chan_info->doorbell = doorbell;  in mhu_db_mbox_xlate()
233 	chan->con_priv = chan_info;  in mhu_db_mbox_xlate()
235 	dev_dbg(mbox->dev, "mbox: created channel phys: %d doorbell: %d\n",  in mhu_db_mbox_xlate()
236 		pchan, doorbell);  in mhu_db_mbox_xlate()
252 	struct arm_mhu *mhu;  in mhu_db_probe()  local
254 	struct device *dev = &adev->dev;  in mhu_db_probe()
255 	struct device_node *np = dev->of_node;  in mhu_db_probe()
260 	if (!of_device_is_compatible(np, "arm,mhu-doorbell"))  in mhu_db_probe()
261 		return -ENODEV;  in mhu_db_probe()
263 	err = of_property_read_u32(np, "#mbox-cells", &cell_count);  in mhu_db_probe()
265 		dev_err(dev, "failed to read #mbox-cells in '%pOF'\n", np);  in mhu_db_probe()
272 		dev_err(dev, "incorrect value of #mbox-cells in '%pOF'\n", np);  in mhu_db_probe()
273 		return -EINVAL;  in mhu_db_probe()
276 	mhu = devm_kzalloc(dev, sizeof(*mhu), GFP_KERNEL);  in mhu_db_probe()
277 	if (!mhu)  in mhu_db_probe()
278 		return -ENOMEM;  in mhu_db_probe()
280 	mhu->base = devm_ioremap_resource(dev, &adev->res);  in mhu_db_probe()
281 	if (IS_ERR(mhu->base))  in mhu_db_probe()
282 		return PTR_ERR(mhu->base);  in mhu_db_probe()
286 		return -ENOMEM;  in mhu_db_probe()
288 	mhu->dev = dev;  in mhu_db_probe()
289 	mhu->mbox.dev = dev;  in mhu_db_probe()
290 	mhu->mbox.chans = chans;  in mhu_db_probe()
291 	mhu->mbox.num_chans = max_chans;  in mhu_db_probe()
292 	mhu->mbox.txdone_irq = false;  in mhu_db_probe()
293 	mhu->mbox.txdone_poll = true;  in mhu_db_probe()
294 	mhu->mbox.txpoll_period = 1;  in mhu_db_probe()
296 	mhu->mbox.of_xlate = mhu_db_mbox_xlate;  in mhu_db_probe()
297 	amba_set_drvdata(adev, mhu);  in mhu_db_probe()
299 	mhu->mbox.ops = &mhu_db_ops;  in mhu_db_probe()
301 	err = devm_mbox_controller_register(dev, &mhu->mbox);  in mhu_db_probe()
308 		int irq = mhu->mlink[i].irq = adev->irq[i];  in mhu_db_probe()
315 		mhu->mlink[i].rx_reg = mhu->base + mhu_reg[i];  in mhu_db_probe()
316 		mhu->mlink[i].tx_reg = mhu->mlink[i].rx_reg + TX_REG_OFFSET;  in mhu_db_probe()
320 						IRQF_ONESHOT, "mhu_db_link", mhu);  in mhu_db_probe()
323 			mbox_controller_unregister(&mhu->mbox);  in mhu_db_probe()
328 	dev_info(dev, "ARM MHU Doorbell mailbox registered\n");  in mhu_db_probe()
343 		.name	= "mhu-doorbell",
351 MODULE_DESCRIPTION("ARM MHU Doorbell Driver");