| // 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; | 
 | 	spinlock_t lock; /* protect access to IPCC registers */ | 
 | 	int irqs[IPCC_IRQ_NUM]; | 
 | 	u32 proc_id; | 
 | 	u32 n_chans; | 
 | 	u32 xcr; | 
 | 	u32 xmr; | 
 | }; | 
 |  | 
 | static inline void stm32_ipcc_set_bits(spinlock_t *lock, void __iomem *reg, | 
 | 				       u32 mask) | 
 | { | 
 | 	unsigned long flags; | 
 |  | 
 | 	spin_lock_irqsave(lock, flags); | 
 | 	writel_relaxed(readl_relaxed(reg) | mask, reg); | 
 | 	spin_unlock_irqrestore(lock, flags); | 
 | } | 
 |  | 
 | static inline void stm32_ipcc_clr_bits(spinlock_t *lock, void __iomem *reg, | 
 | 				       u32 mask) | 
 | { | 
 | 	unsigned long flags; | 
 |  | 
 | 	spin_lock_irqsave(lock, flags); | 
 | 	writel_relaxed(readl_relaxed(reg) & ~mask, reg); | 
 | 	spin_unlock_irqrestore(lock, flags); | 
 | } | 
 |  | 
 | 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->lock, 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->lock, 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->lock, ipcc->reg_proc + IPCC_XSCR, | 
 | 			    TX_BIT_CHAN(chan)); | 
 |  | 
 | 	/* unmask 'tx channel free' interrupt */ | 
 | 	stm32_ipcc_clr_bits(&ipcc->lock, 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->lock, 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->lock, 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; | 
 |  | 
 | 	spin_lock_init(&ipcc->lock); | 
 |  | 
 | 	/* 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->lock, ipcc->reg_proc + IPCC_XMR, | 
 | 			    RX_BIT_MASK | TX_BIT_MASK); | 
 | 	stm32_ipcc_set_bits(&ipcc->lock, ipcc->reg_proc + IPCC_XCR, | 
 | 			    XCR_RXOIE | XCR_TXOIE); | 
 |  | 
 | 	/* wakeup */ | 
 | 	if (of_property_read_bool(np, "wakeup-source")) { | 
 | 		device_set_wakeup_capable(dev, true); | 
 |  | 
 | 		ret = dev_pm_set_wake_irq(dev, ipcc->irqs[IPCC_IRQ_RX]); | 
 | 		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 (of_property_read_bool(np, "wakeup-source")) | 
 | 		dev_pm_clear_wake_irq(dev); | 
 | err_init_wkp: | 
 | 	device_set_wakeup_capable(dev, false); | 
 | err_clk: | 
 | 	clk_disable_unprepare(ipcc->clk); | 
 | 	return ret; | 
 | } | 
 |  | 
 | static int stm32_ipcc_remove(struct platform_device *pdev) | 
 | { | 
 | 	struct device *dev = &pdev->dev; | 
 |  | 
 | 	if (of_property_read_bool(dev->of_node, "wakeup-source")) | 
 | 		dev_pm_clear_wake_irq(&pdev->dev); | 
 |  | 
 | 	device_set_wakeup_capable(dev, false); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | #ifdef CONFIG_PM_SLEEP | 
 | 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); | 
 |  | 
 | 	return 0; | 
 | } | 
 |  | 
 | static int stm32_ipcc_resume(struct device *dev) | 
 | { | 
 | 	struct stm32_ipcc *ipcc = dev_get_drvdata(dev); | 
 |  | 
 | 	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"); |