drivers/mailbox/stm32-ipcc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
  * Authors: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
  *          Fabien Dessenne <fabien.dessenne@st.com> for STMicroelectronics.
  */

 #include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/mailbox_controller.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_wakeirq.h>

 #define IPCC_XCR		0x000
 #define XCR_RXOIE		BIT(0)
 #define XCR_TXOIE		BIT(16)

 #define IPCC_XMR		0x004
 #define IPCC_XSCR		0x008
 #define IPCC_XTOYSR		0x00c

 #define IPCC_PROC_OFFST		0x010

 #define IPCC_HWCFGR		0x3f0
 #define IPCFGR_CHAN_MASK	GENMASK(7, 0)

 #define IPCC_VER		0x3f4
 #define VER_MINREV_MASK		GENMASK(3, 0)
 #define VER_MAJREV_MASK		GENMASK(7, 4)

 #define RX_BIT_MASK		GENMASK(15, 0)
 #define RX_BIT_CHAN(chan)	BIT(chan)
 #define TX_BIT_SHIFT		16
 #define TX_BIT_MASK		GENMASK(31, 16)
 #define TX_BIT_CHAN(chan)	BIT(TX_BIT_SHIFT + (chan))

 #define STM32_MAX_PROCS		2

 enum {
 	IPCC_IRQ_RX,
 	IPCC_IRQ_TX,
 	IPCC_IRQ_NUM,
 };

 struct stm32_ipcc {
 	struct mbox_controller controller;
 	void __iomem *reg_base;
 	void __iomem *reg_proc;
 	struct clk *clk;
 	int irqs[IPCC_IRQ_NUM];
 	int wkp;
 	u32 proc_id;
 	u32 n_chans;
 	u32 xcr;
 	u32 xmr;
 };

 static inline void stm32_ipcc_set_bits(void __iomem *reg, u32 mask)
 {
 	writel_relaxed(readl_relaxed(reg) | mask, reg);
 }

 static inline void stm32_ipcc_clr_bits(void __iomem *reg, u32 mask)
 {
 	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
 }

 static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
 {
 	struct stm32_ipcc *ipcc = data;
 	struct device *dev = ipcc->controller.dev;
 	u32 status, mr, tosr, chan;
 	irqreturn_t ret = IRQ_NONE;
 	int proc_offset;

 	/* read 'channel occupied' status from other proc */
 	proc_offset = ipcc->proc_id ? -IPCC_PROC_OFFST : IPCC_PROC_OFFST;
 	tosr = readl_relaxed(ipcc->reg_proc + proc_offset + IPCC_XTOYSR);
 	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);

 	/* search for unmasked 'channel occupied' */
 	status = tosr & FIELD_GET(RX_BIT_MASK, ~mr);

 	for (chan = 0; chan < ipcc->n_chans; chan++) {
 		if (!(status & (1 << chan)))
 			continue;

 		dev_dbg(dev, "%s: chan:%d rx\n", __func__, chan);

 		mbox_chan_received_data(&ipcc->controller.chans[chan], NULL);

 		stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR,
 				    RX_BIT_CHAN(chan));

 		ret = IRQ_HANDLED;
 	}

 	return ret;
 }

 static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data)
 {
 	struct stm32_ipcc *ipcc = data;
 	struct device *dev = ipcc->controller.dev;
 	u32 status, mr, tosr, chan;
 	irqreturn_t ret = IRQ_NONE;

 	tosr = readl_relaxed(ipcc->reg_proc + IPCC_XTOYSR);
 	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);

 	/* search for unmasked 'channel free' */
 	status = ~tosr & FIELD_GET(TX_BIT_MASK, ~mr);

 	for (chan = 0; chan < ipcc->n_chans ; chan++) {
 		if (!(status & (1 << chan)))
 			continue;

 		dev_dbg(dev, "%s: chan:%d tx\n", __func__, chan);

 		/* mask 'tx channel free' interrupt */
 		stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
 				    TX_BIT_CHAN(chan));

 		mbox_chan_txdone(&ipcc->controller.chans[chan], 0);

 		ret = IRQ_HANDLED;
 	}

 	return ret;
 }

 static int stm32_ipcc_send_data(struct mbox_chan *link, void *data)
 {
 	unsigned int chan = (unsigned int)link->con_priv;
 	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
 					       controller);

 	dev_dbg(ipcc->controller.dev, "%s: chan:%d\n", __func__, chan);

 	/* set channel n occupied */
 	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR, TX_BIT_CHAN(chan));

 	/* unmask 'tx channel free' interrupt */
 	stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, TX_BIT_CHAN(chan));

 	return 0;
 }

 static int stm32_ipcc_startup(struct mbox_chan *link)
 {
 	unsigned int chan = (unsigned int)link->con_priv;
 	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
 					       controller);
 	int ret;

 	ret = clk_prepare_enable(ipcc->clk);
 	if (ret) {
 		dev_err(ipcc->controller.dev, "can not enable the clock\n");
 		return ret;
 	}

 	/* unmask 'rx channel occupied' interrupt */
 	stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, RX_BIT_CHAN(chan));

 	return 0;
 }

 static void stm32_ipcc_shutdown(struct mbox_chan *link)
 {
 	unsigned int chan = (unsigned int)link->con_priv;
 	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
 					       controller);

 	/* mask rx/tx interrupt */
 	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
 			    RX_BIT_CHAN(chan) | TX_BIT_CHAN(chan));

 	clk_disable_unprepare(ipcc->clk);
 }

 static const struct mbox_chan_ops stm32_ipcc_ops = {
 	.send_data	= stm32_ipcc_send_data,
 	.startup	= stm32_ipcc_startup,
 	.shutdown	= stm32_ipcc_shutdown,
 };

 static int stm32_ipcc_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct device_node *np = dev->of_node;
 	struct stm32_ipcc *ipcc;
 	struct resource *res;
 	unsigned int i;
 	int ret;
 	u32 ip_ver;
 	static const char * const irq_name[] = {"rx", "tx"};
 	irq_handler_t irq_thread[] = {stm32_ipcc_rx_irq, stm32_ipcc_tx_irq};

 	if (!np) {
 		dev_err(dev, "No DT found\n");
 		return -ENODEV;
 	}

 	ipcc = devm_kzalloc(dev, sizeof(*ipcc), GFP_KERNEL);
 	if (!ipcc)
 		return -ENOMEM;

 	/* proc_id */
 	if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) {
 		dev_err(dev, "Missing st,proc-id\n");
 		return -ENODEV;
 	}

 	if (ipcc->proc_id >= STM32_MAX_PROCS) {
 		dev_err(dev, "Invalid proc_id (%d)\n", ipcc->proc_id);
 		return -EINVAL;
 	}

 	/* regs */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	ipcc->reg_base = devm_ioremap_resource(dev, res);
 	if (IS_ERR(ipcc->reg_base))
 		return PTR_ERR(ipcc->reg_base);

 	ipcc->reg_proc = ipcc->reg_base + ipcc->proc_id * IPCC_PROC_OFFST;

 	/* clock */
 	ipcc->clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(ipcc->clk))
 		return PTR_ERR(ipcc->clk);

 	ret = clk_prepare_enable(ipcc->clk);
 	if (ret) {
 		dev_err(dev, "can not enable the clock\n");
 		return ret;
 	}

 	/* irq */
 	for (i = 0; i < IPCC_IRQ_NUM; i++) {
 		ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]);
 		if (ipcc->irqs[i] < 0) {
 			if (ipcc->irqs[i] != -EPROBE_DEFER)
 				dev_err(dev, "no IRQ specified %s\n",
 					irq_name[i]);
 			ret = ipcc->irqs[i];
 			goto err_clk;
 		}

 		ret = devm_request_threaded_irq(dev, ipcc->irqs[i], NULL,
 						irq_thread[i], IRQF_ONESHOT,
 						dev_name(dev), ipcc);
 		if (ret) {
 			dev_err(dev, "failed to request irq %d (%d)\n", i, ret);
 			goto err_clk;
 		}
 	}

 	/* mask and enable rx/tx irq */
 	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
 			    RX_BIT_MASK | TX_BIT_MASK);
 	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XCR, XCR_RXOIE | XCR_TXOIE);

 	/* wakeup */
 	if (of_property_read_bool(np, "wakeup-source")) {
 		ipcc->wkp = platform_get_irq_byname(pdev, "wakeup");
 		if (ipcc->wkp < 0) {
 			if (ipcc->wkp != -EPROBE_DEFER)
 				dev_err(dev, "could not get wakeup IRQ\n");
 			ret = ipcc->wkp;
 			goto err_clk;
 		}

 		device_set_wakeup_capable(dev, true);
 		ret = dev_pm_set_dedicated_wake_irq(dev, ipcc->wkp);
 		if (ret) {
 			dev_err(dev, "Failed to set wake up irq\n");
 			goto err_init_wkp;
 		}
 	}

 	/* mailbox controller */
 	ipcc->n_chans = readl_relaxed(ipcc->reg_base + IPCC_HWCFGR);
 	ipcc->n_chans &= IPCFGR_CHAN_MASK;

 	ipcc->controller.dev = dev;
 	ipcc->controller.txdone_irq = true;
 	ipcc->controller.ops = &stm32_ipcc_ops;
 	ipcc->controller.num_chans = ipcc->n_chans;
 	ipcc->controller.chans = devm_kcalloc(dev, ipcc->controller.num_chans,
 					      sizeof(*ipcc->controller.chans),
 					      GFP_KERNEL);
 	if (!ipcc->controller.chans) {
 		ret = -ENOMEM;
 		goto err_irq_wkp;
 	}

 	for (i = 0; i < ipcc->controller.num_chans; i++)
 		ipcc->controller.chans[i].con_priv = (void *)i;

 	ret = devm_mbox_controller_register(dev, &ipcc->controller);
 	if (ret)
 		goto err_irq_wkp;

 	platform_set_drvdata(pdev, ipcc);

 	ip_ver = readl_relaxed(ipcc->reg_base + IPCC_VER);

 	dev_info(dev, "ipcc rev:%ld.%ld enabled, %d chans, proc %d\n",
 		 FIELD_GET(VER_MAJREV_MASK, ip_ver),
 		 FIELD_GET(VER_MINREV_MASK, ip_ver),
 		 ipcc->controller.num_chans, ipcc->proc_id);

 	clk_disable_unprepare(ipcc->clk);
 	return 0;

 err_irq_wkp:
 	if (ipcc->wkp)
 		dev_pm_clear_wake_irq(dev);
 err_init_wkp:
 	device_init_wakeup(dev, false);
 err_clk:
 	clk_disable_unprepare(ipcc->clk);
 	return ret;
 }

 static int stm32_ipcc_remove(struct platform_device *pdev)
 {
 	struct stm32_ipcc *ipcc = platform_get_drvdata(pdev);

 	if (ipcc->wkp)
 		dev_pm_clear_wake_irq(&pdev->dev);

 	device_init_wakeup(&pdev->dev, false);

 	return 0;
 }

 #ifdef CONFIG_PM_SLEEP
 static void stm32_ipcc_set_irq_wake(struct device *dev, bool enable)
 {
 	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);
 	unsigned int i;

 	if (device_may_wakeup(dev))
 		for (i = 0; i < IPCC_IRQ_NUM; i++)
 			irq_set_irq_wake(ipcc->irqs[i], enable);
 }

 static int stm32_ipcc_suspend(struct device *dev)
 {
 	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);

 	ipcc->xmr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
 	ipcc->xcr = readl_relaxed(ipcc->reg_proc + IPCC_XCR);

 	stm32_ipcc_set_irq_wake(dev, true);

 	return 0;
 }

 static int stm32_ipcc_resume(struct device *dev)
 {
 	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);

 	stm32_ipcc_set_irq_wake(dev, false);

 	writel_relaxed(ipcc->xmr, ipcc->reg_proc + IPCC_XMR);
 	writel_relaxed(ipcc->xcr, ipcc->reg_proc + IPCC_XCR);

 	return 0;
 }
 #endif

 static SIMPLE_DEV_PM_OPS(stm32_ipcc_pm_ops,
 			 stm32_ipcc_suspend, stm32_ipcc_resume);

 static const struct of_device_id stm32_ipcc_of_match[] = {
 	{ .compatible = "st,stm32mp1-ipcc" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, stm32_ipcc_of_match);

 static struct platform_driver stm32_ipcc_driver = {
 	.driver = {
 		.name = "stm32-ipcc",
 		.pm = &stm32_ipcc_pm_ops,
 		.of_match_table = stm32_ipcc_of_match,
 	},
 	.probe		= stm32_ipcc_probe,
 	.remove		= stm32_ipcc_remove,
 };

 module_platform_driver(stm32_ipcc_driver);

 MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
 MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
 MODULE_DESCRIPTION("STM32 IPCC driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) STMicroelectronics 2018 - All Rights Reserved
	* Authors: Ludovic Barre <ludovic.barre@st.com> for STMicroelectronics.
	* Fabien Dessenne <fabien.dessenne@st.com> for STMicroelectronics.
	*/

	#include <linux/bitfield.h>
	#include <linux/clk.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/mailbox_controller.h>
	#include <linux/module.h>
	#include <linux/platform_device.h>
	#include <linux/pm_wakeirq.h>

	#define IPCC_XCR 0x000
	#define XCR_RXOIE BIT(0)
	#define XCR_TXOIE BIT(16)

	#define IPCC_XMR 0x004
	#define IPCC_XSCR 0x008
	#define IPCC_XTOYSR 0x00c

	#define IPCC_PROC_OFFST 0x010

	#define IPCC_HWCFGR 0x3f0
	#define IPCFGR_CHAN_MASK GENMASK(7, 0)

	#define IPCC_VER 0x3f4
	#define VER_MINREV_MASK GENMASK(3, 0)
	#define VER_MAJREV_MASK GENMASK(7, 4)

	#define RX_BIT_MASK GENMASK(15, 0)
	#define RX_BIT_CHAN(chan) BIT(chan)
	#define TX_BIT_SHIFT 16
	#define TX_BIT_MASK GENMASK(31, 16)
	#define TX_BIT_CHAN(chan) BIT(TX_BIT_SHIFT + (chan))

	#define STM32_MAX_PROCS 2

	enum {
	IPCC_IRQ_RX,
	IPCC_IRQ_TX,
	IPCC_IRQ_NUM,
	};

	struct stm32_ipcc {
	struct mbox_controller controller;
	void __iomem *reg_base;
	void __iomem *reg_proc;
	struct clk *clk;
	int irqs[IPCC_IRQ_NUM];
	int wkp;
	u32 proc_id;
	u32 n_chans;
	u32 xcr;
	u32 xmr;
	};

	static inline void stm32_ipcc_set_bits(void __iomem *reg, u32 mask)
	{
	writel_relaxed(readl_relaxed(reg) \| mask, reg);
	}

	static inline void stm32_ipcc_clr_bits(void __iomem *reg, u32 mask)
	{
	writel_relaxed(readl_relaxed(reg) & ~mask, reg);
	}

	static irqreturn_t stm32_ipcc_rx_irq(int irq, void *data)
	{
	struct stm32_ipcc *ipcc = data;
	struct device *dev = ipcc->controller.dev;
	u32 status, mr, tosr, chan;
	irqreturn_t ret = IRQ_NONE;
	int proc_offset;

	/* read 'channel occupied' status from other proc */
	proc_offset = ipcc->proc_id ? -IPCC_PROC_OFFST : IPCC_PROC_OFFST;
	tosr = readl_relaxed(ipcc->reg_proc + proc_offset + IPCC_XTOYSR);
	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);

	/* search for unmasked 'channel occupied' */
	status = tosr & FIELD_GET(RX_BIT_MASK, ~mr);

	for (chan = 0; chan < ipcc->n_chans; chan++) {
	if (!(status & (1 << chan)))
	continue;

	dev_dbg(dev, "%s: chan:%d rx\n", __func__, chan);

	mbox_chan_received_data(&ipcc->controller.chans[chan], NULL);

	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR,
	RX_BIT_CHAN(chan));

	ret = IRQ_HANDLED;
	}

	return ret;
	}

	static irqreturn_t stm32_ipcc_tx_irq(int irq, void *data)
	{
	struct stm32_ipcc *ipcc = data;
	struct device *dev = ipcc->controller.dev;
	u32 status, mr, tosr, chan;
	irqreturn_t ret = IRQ_NONE;

	tosr = readl_relaxed(ipcc->reg_proc + IPCC_XTOYSR);
	mr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);

	/* search for unmasked 'channel free' */
	status = ~tosr & FIELD_GET(TX_BIT_MASK, ~mr);

	for (chan = 0; chan < ipcc->n_chans ; chan++) {
	if (!(status & (1 << chan)))
	continue;

	dev_dbg(dev, "%s: chan:%d tx\n", __func__, chan);

	/* mask 'tx channel free' interrupt */
	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
	TX_BIT_CHAN(chan));

	mbox_chan_txdone(&ipcc->controller.chans[chan], 0);

	ret = IRQ_HANDLED;
	}

	return ret;
	}

	static int stm32_ipcc_send_data(struct mbox_chan link, void data)
	{
	unsigned int chan = (unsigned int)link->con_priv;
	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
	controller);

	dev_dbg(ipcc->controller.dev, "%s: chan:%d\n", __func__, chan);

	/* set channel n occupied */
	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XSCR, TX_BIT_CHAN(chan));

	/* unmask 'tx channel free' interrupt */
	stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, TX_BIT_CHAN(chan));

	return 0;
	}

	static int stm32_ipcc_startup(struct mbox_chan *link)
	{
	unsigned int chan = (unsigned int)link->con_priv;
	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
	controller);
	int ret;

	ret = clk_prepare_enable(ipcc->clk);
	if (ret) {
	dev_err(ipcc->controller.dev, "can not enable the clock\n");
	return ret;
	}

	/* unmask 'rx channel occupied' interrupt */
	stm32_ipcc_clr_bits(ipcc->reg_proc + IPCC_XMR, RX_BIT_CHAN(chan));

	return 0;
	}

	static void stm32_ipcc_shutdown(struct mbox_chan *link)
	{
	unsigned int chan = (unsigned int)link->con_priv;
	struct stm32_ipcc *ipcc = container_of(link->mbox, struct stm32_ipcc,
	controller);

	/* mask rx/tx interrupt */
	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
	RX_BIT_CHAN(chan) \| TX_BIT_CHAN(chan));

	clk_disable_unprepare(ipcc->clk);
	}

	static const struct mbox_chan_ops stm32_ipcc_ops = {
	.send_data = stm32_ipcc_send_data,
	.startup = stm32_ipcc_startup,
	.shutdown = stm32_ipcc_shutdown,
	};

	static int stm32_ipcc_probe(struct platform_device *pdev)
	{
	struct device *dev = &pdev->dev;
	struct device_node *np = dev->of_node;
	struct stm32_ipcc *ipcc;
	struct resource *res;
	unsigned int i;
	int ret;
	u32 ip_ver;
	static const char * const irq_name[] = {"rx", "tx"};
	irq_handler_t irq_thread[] = {stm32_ipcc_rx_irq, stm32_ipcc_tx_irq};

	if (!np) {
	dev_err(dev, "No DT found\n");
	return -ENODEV;
	}

	ipcc = devm_kzalloc(dev, sizeof(*ipcc), GFP_KERNEL);
	if (!ipcc)
	return -ENOMEM;

	/* proc_id */
	if (of_property_read_u32(np, "st,proc-id", &ipcc->proc_id)) {
	dev_err(dev, "Missing st,proc-id\n");
	return -ENODEV;
	}

	if (ipcc->proc_id >= STM32_MAX_PROCS) {
	dev_err(dev, "Invalid proc_id (%d)\n", ipcc->proc_id);
	return -EINVAL;
	}

	/* regs */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ipcc->reg_base = devm_ioremap_resource(dev, res);
	if (IS_ERR(ipcc->reg_base))
	return PTR_ERR(ipcc->reg_base);

	ipcc->reg_proc = ipcc->reg_base + ipcc->proc_id * IPCC_PROC_OFFST;

	/* clock */
	ipcc->clk = devm_clk_get(dev, NULL);
	if (IS_ERR(ipcc->clk))
	return PTR_ERR(ipcc->clk);

	ret = clk_prepare_enable(ipcc->clk);
	if (ret) {
	dev_err(dev, "can not enable the clock\n");
	return ret;
	}

	/* irq */
	for (i = 0; i < IPCC_IRQ_NUM; i++) {
	ipcc->irqs[i] = platform_get_irq_byname(pdev, irq_name[i]);
	if (ipcc->irqs[i] < 0) {
	if (ipcc->irqs[i] != -EPROBE_DEFER)
	dev_err(dev, "no IRQ specified %s\n",
	irq_name[i]);
	ret = ipcc->irqs[i];
	goto err_clk;
	}

	ret = devm_request_threaded_irq(dev, ipcc->irqs[i], NULL,
	irq_thread[i], IRQF_ONESHOT,
	dev_name(dev), ipcc);
	if (ret) {
	dev_err(dev, "failed to request irq %d (%d)\n", i, ret);
	goto err_clk;
	}
	}

	/* mask and enable rx/tx irq */
	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XMR,
	RX_BIT_MASK \| TX_BIT_MASK);
	stm32_ipcc_set_bits(ipcc->reg_proc + IPCC_XCR, XCR_RXOIE \| XCR_TXOIE);

	/* wakeup */
	if (of_property_read_bool(np, "wakeup-source")) {
	ipcc->wkp = platform_get_irq_byname(pdev, "wakeup");
	if (ipcc->wkp < 0) {
	if (ipcc->wkp != -EPROBE_DEFER)
	dev_err(dev, "could not get wakeup IRQ\n");
	ret = ipcc->wkp;
	goto err_clk;
	}

	device_set_wakeup_capable(dev, true);
	ret = dev_pm_set_dedicated_wake_irq(dev, ipcc->wkp);
	if (ret) {
	dev_err(dev, "Failed to set wake up irq\n");
	goto err_init_wkp;
	}
	}

	/* mailbox controller */
	ipcc->n_chans = readl_relaxed(ipcc->reg_base + IPCC_HWCFGR);
	ipcc->n_chans &= IPCFGR_CHAN_MASK;

	ipcc->controller.dev = dev;
	ipcc->controller.txdone_irq = true;
	ipcc->controller.ops = &stm32_ipcc_ops;
	ipcc->controller.num_chans = ipcc->n_chans;
	ipcc->controller.chans = devm_kcalloc(dev, ipcc->controller.num_chans,
	sizeof(*ipcc->controller.chans),
	GFP_KERNEL);
	if (!ipcc->controller.chans) {
	ret = -ENOMEM;
	goto err_irq_wkp;
	}

	for (i = 0; i < ipcc->controller.num_chans; i++)
	ipcc->controller.chans[i].con_priv = (void *)i;

	ret = devm_mbox_controller_register(dev, &ipcc->controller);
	if (ret)
	goto err_irq_wkp;

	platform_set_drvdata(pdev, ipcc);

	ip_ver = readl_relaxed(ipcc->reg_base + IPCC_VER);

	dev_info(dev, "ipcc rev:%ld.%ld enabled, %d chans, proc %d\n",
	FIELD_GET(VER_MAJREV_MASK, ip_ver),
	FIELD_GET(VER_MINREV_MASK, ip_ver),
	ipcc->controller.num_chans, ipcc->proc_id);

	clk_disable_unprepare(ipcc->clk);
	return 0;

	err_irq_wkp:
	if (ipcc->wkp)
	dev_pm_clear_wake_irq(dev);
	err_init_wkp:
	device_init_wakeup(dev, false);
	err_clk:
	clk_disable_unprepare(ipcc->clk);
	return ret;
	}

	static int stm32_ipcc_remove(struct platform_device *pdev)
	{
	struct stm32_ipcc *ipcc = platform_get_drvdata(pdev);

	if (ipcc->wkp)
	dev_pm_clear_wake_irq(&pdev->dev);

	device_init_wakeup(&pdev->dev, false);

	return 0;
	}

	#ifdef CONFIG_PM_SLEEP
	static void stm32_ipcc_set_irq_wake(struct device *dev, bool enable)
	{
	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);
	unsigned int i;

	if (device_may_wakeup(dev))
	for (i = 0; i < IPCC_IRQ_NUM; i++)
	irq_set_irq_wake(ipcc->irqs[i], enable);
	}

	static int stm32_ipcc_suspend(struct device *dev)
	{
	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);

	ipcc->xmr = readl_relaxed(ipcc->reg_proc + IPCC_XMR);
	ipcc->xcr = readl_relaxed(ipcc->reg_proc + IPCC_XCR);

	stm32_ipcc_set_irq_wake(dev, true);

	return 0;
	}

	static int stm32_ipcc_resume(struct device *dev)
	{
	struct stm32_ipcc *ipcc = dev_get_drvdata(dev);

	stm32_ipcc_set_irq_wake(dev, false);

	writel_relaxed(ipcc->xmr, ipcc->reg_proc + IPCC_XMR);
	writel_relaxed(ipcc->xcr, ipcc->reg_proc + IPCC_XCR);

	return 0;
	}
	#endif

	static SIMPLE_DEV_PM_OPS(stm32_ipcc_pm_ops,
	stm32_ipcc_suspend, stm32_ipcc_resume);

	static const struct of_device_id stm32_ipcc_of_match[] = {
	{ .compatible = "st,stm32mp1-ipcc" },
	{},
	};
	MODULE_DEVICE_TABLE(of, stm32_ipcc_of_match);

	static struct platform_driver stm32_ipcc_driver = {
	.driver = {
	.name = "stm32-ipcc",
	.pm = &stm32_ipcc_pm_ops,
	.of_match_table = stm32_ipcc_of_match,
	},
	.probe = stm32_ipcc_probe,
	.remove = stm32_ipcc_remove,
	};

	module_platform_driver(stm32_ipcc_driver);

	MODULE_AUTHOR("Ludovic Barre <ludovic.barre@st.com>");
	MODULE_AUTHOR("Fabien Dessenne <fabien.dessenne@st.com>");
	MODULE_DESCRIPTION("STM32 IPCC driver");
	MODULE_LICENSE("GPL v2");