drivers/input/serio/sa1111ps2.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  linux/drivers/input/serio/sa1111ps2.c
  *
  *  Copyright (C) 2002 Russell King
  */
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/input.h>
 #include <linux/serio.h>
 #include <linux/errno.h>
 #include <linux/interrupt.h>
 #include <linux/ioport.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>

 #include <asm/io.h>

 #include <asm/hardware/sa1111.h>

 #define PS2CR		0x0000
 #define PS2STAT		0x0004
 #define PS2DATA		0x0008
 #define PS2CLKDIV	0x000c
 #define PS2PRECNT	0x0010

 #define PS2CR_ENA	0x08
 #define PS2CR_FKD	0x02
 #define PS2CR_FKC	0x01

 #define PS2STAT_STP	0x0100
 #define PS2STAT_TXE	0x0080
 #define PS2STAT_TXB	0x0040
 #define PS2STAT_RXF	0x0020
 #define PS2STAT_RXB	0x0010
 #define PS2STAT_ENA	0x0008
 #define PS2STAT_RXP	0x0004
 #define PS2STAT_KBD	0x0002
 #define PS2STAT_KBC	0x0001

 struct ps2if {
 	struct serio		*io;
 	struct sa1111_dev	*dev;
 	void __iomem		*base;
 	int			rx_irq;
 	int			tx_irq;
 	unsigned int		open;
 	spinlock_t		lock;
 	unsigned int		head;
 	unsigned int		tail;
 	unsigned char		buf[4];
 };

 /*
  * Read all bytes waiting in the PS2 port.  There should be
  * at the most one, but we loop for safety.  If there was a
  * framing error, we have to manually clear the status.
  */
 static irqreturn_t ps2_rxint(int irq, void *dev_id)
 {
 	struct ps2if *ps2if = dev_id;
 	unsigned int scancode, flag, status;

 	status = readl_relaxed(ps2if->base + PS2STAT);
 	while (status & PS2STAT_RXF) {
 		if (status & PS2STAT_STP)
 			writel_relaxed(PS2STAT_STP, ps2if->base + PS2STAT);

 		flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) |
 		       (status & PS2STAT_RXP ? 0 : SERIO_PARITY);

 		scancode = readl_relaxed(ps2if->base + PS2DATA) & 0xff;

 		if (hweight8(scancode) & 1)
 			flag ^= SERIO_PARITY;

 		serio_interrupt(ps2if->io, scancode, flag);

 		status = readl_relaxed(ps2if->base + PS2STAT);
         }

         return IRQ_HANDLED;
 }

 /*
  * Completion of ps2 write
  */
 static irqreturn_t ps2_txint(int irq, void *dev_id)
 {
 	struct ps2if *ps2if = dev_id;
 	unsigned int status;

 	spin_lock(&ps2if->lock);
 	status = readl_relaxed(ps2if->base + PS2STAT);
 	if (ps2if->head == ps2if->tail) {
 		disable_irq_nosync(irq);
 		/* done */
 	} else if (status & PS2STAT_TXE) {
 		writel_relaxed(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA);
 		ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
 	}
 	spin_unlock(&ps2if->lock);

 	return IRQ_HANDLED;
 }

 /*
  * Write a byte to the PS2 port.  We have to wait for the
  * port to indicate that the transmitter is empty.
  */
 static int ps2_write(struct serio *io, unsigned char val)
 {
 	struct ps2if *ps2if = io->port_data;
 	unsigned long flags;
 	unsigned int head;

 	spin_lock_irqsave(&ps2if->lock, flags);

 	/*
 	 * If the TX register is empty, we can go straight out.
 	 */
 	if (readl_relaxed(ps2if->base + PS2STAT) & PS2STAT_TXE) {
 		writel_relaxed(val, ps2if->base + PS2DATA);
 	} else {
 		if (ps2if->head == ps2if->tail)
 			enable_irq(ps2if->tx_irq);
 		head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
 		if (head != ps2if->tail) {
 			ps2if->buf[ps2if->head] = val;
 			ps2if->head = head;
 		}
 	}

 	spin_unlock_irqrestore(&ps2if->lock, flags);
 	return 0;
 }

 static int ps2_open(struct serio *io)
 {
 	struct ps2if *ps2if = io->port_data;
 	int ret;

 	ret = sa1111_enable_device(ps2if->dev);
 	if (ret)
 		return ret;

 	ret = request_irq(ps2if->rx_irq, ps2_rxint, 0,
 			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 	if (ret) {
 		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 			ps2if->rx_irq, ret);
 		sa1111_disable_device(ps2if->dev);
 		return ret;
 	}

 	ret = request_irq(ps2if->tx_irq, ps2_txint, 0,
 			  SA1111_DRIVER_NAME(ps2if->dev), ps2if);
 	if (ret) {
 		printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
 			ps2if->tx_irq, ret);
 		free_irq(ps2if->rx_irq, ps2if);
 		sa1111_disable_device(ps2if->dev);
 		return ret;
 	}

 	ps2if->open = 1;

 	enable_irq_wake(ps2if->rx_irq);

 	writel_relaxed(PS2CR_ENA, ps2if->base + PS2CR);
 	return 0;
 }

 static void ps2_close(struct serio *io)
 {
 	struct ps2if *ps2if = io->port_data;

 	writel_relaxed(0, ps2if->base + PS2CR);

 	disable_irq_wake(ps2if->rx_irq);

 	ps2if->open = 0;

 	free_irq(ps2if->tx_irq, ps2if);
 	free_irq(ps2if->rx_irq, ps2if);

 	sa1111_disable_device(ps2if->dev);
 }

 /*
  * Clear the input buffer.
  */
 static void ps2_clear_input(struct ps2if *ps2if)
 {
 	int maxread = 100;

 	while (maxread--) {
 		if ((readl_relaxed(ps2if->base + PS2DATA) & 0xff) == 0xff)
 			break;
 	}
 }

 static unsigned int ps2_test_one(struct ps2if *ps2if,
 					   unsigned int mask)
 {
 	unsigned int val;

 	writel_relaxed(PS2CR_ENA | mask, ps2if->base + PS2CR);

 	udelay(10);

 	val = readl_relaxed(ps2if->base + PS2STAT);
 	return val & (PS2STAT_KBC | PS2STAT_KBD);
 }

 /*
  * Test the keyboard interface.  We basically check to make sure that
  * we can drive each line to the keyboard independently of each other.
  */
 static int ps2_test(struct ps2if *ps2if)
 {
 	unsigned int stat;
 	int ret = 0;

 	stat = ps2_test_one(ps2if, PS2CR_FKC);
 	if (stat != PS2STAT_KBD) {
 		printk("PS/2 interface test failed[1]: %02x\n", stat);
 		ret = -ENODEV;
 	}

 	stat = ps2_test_one(ps2if, 0);
 	if (stat != (PS2STAT_KBC | PS2STAT_KBD)) {
 		printk("PS/2 interface test failed[2]: %02x\n", stat);
 		ret = -ENODEV;
 	}

 	stat = ps2_test_one(ps2if, PS2CR_FKD);
 	if (stat != PS2STAT_KBC) {
 		printk("PS/2 interface test failed[3]: %02x\n", stat);
 		ret = -ENODEV;
 	}

 	writel_relaxed(0, ps2if->base + PS2CR);

 	return ret;
 }

 /*
  * Add one device to this driver.
  */
 static int ps2_probe(struct sa1111_dev *dev)
 {
 	struct ps2if *ps2if;
 	struct serio *serio;
 	int ret;

 	ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 	if (!ps2if || !serio) {
 		ret = -ENOMEM;
 		goto free;
 	}

 	serio->id.type		= SERIO_8042;
 	serio->write		= ps2_write;
 	serio->open		= ps2_open;
 	serio->close		= ps2_close;
 	strlcpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
 	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
 	serio->port_data	= ps2if;
 	serio->dev.parent	= &dev->dev;
 	ps2if->io		= serio;
 	ps2if->dev		= dev;
 	sa1111_set_drvdata(dev, ps2if);

 	spin_lock_init(&ps2if->lock);

 	ps2if->rx_irq = sa1111_get_irq(dev, 0);
 	if (ps2if->rx_irq <= 0) {
 		ret = ps2if->rx_irq ? : -ENXIO;
 		goto free;
 	}

 	ps2if->tx_irq = sa1111_get_irq(dev, 1);
 	if (ps2if->tx_irq <= 0) {
 		ret = ps2if->tx_irq ? : -ENXIO;
 		goto free;
 	}

 	/*
 	 * Request the physical region for this PS2 port.
 	 */
 	if (!request_mem_region(dev->res.start,
 				dev->res.end - dev->res.start + 1,
 				SA1111_DRIVER_NAME(dev))) {
 		ret = -EBUSY;
 		goto free;
 	}

 	/*
 	 * Our parent device has already mapped the region.
 	 */
 	ps2if->base = dev->mapbase;

 	sa1111_enable_device(ps2if->dev);

 	/* Incoming clock is 8MHz */
 	writel_relaxed(0, ps2if->base + PS2CLKDIV);
 	writel_relaxed(127, ps2if->base + PS2PRECNT);

 	/*
 	 * Flush any pending input.
 	 */
 	ps2_clear_input(ps2if);

 	/*
 	 * Test the keyboard interface.
 	 */
 	ret = ps2_test(ps2if);
 	if (ret)
 		goto out;

 	/*
 	 * Flush any pending input.
 	 */
 	ps2_clear_input(ps2if);

 	sa1111_disable_device(ps2if->dev);
 	serio_register_port(ps2if->io);
 	return 0;

  out:
 	sa1111_disable_device(ps2if->dev);
 	release_mem_region(dev->res.start, resource_size(&dev->res));
  free:
 	sa1111_set_drvdata(dev, NULL);
 	kfree(ps2if);
 	kfree(serio);
 	return ret;
 }

 /*
  * Remove one device from this driver.
  */
 static void ps2_remove(struct sa1111_dev *dev)
 {
 	struct ps2if *ps2if = sa1111_get_drvdata(dev);

 	serio_unregister_port(ps2if->io);
 	release_mem_region(dev->res.start, resource_size(&dev->res));
 	sa1111_set_drvdata(dev, NULL);

 	kfree(ps2if);
 }

 /*
  * Our device driver structure
  */
 static struct sa1111_driver ps2_driver = {
 	.drv = {
 		.name	= "sa1111-ps2",
 		.owner	= THIS_MODULE,
 	},
 	.devid		= SA1111_DEVID_PS2,
 	.probe		= ps2_probe,
 	.remove		= ps2_remove,
 };

 static int __init ps2_init(void)
 {
 	return sa1111_driver_register(&ps2_driver);
 }

 static void __exit ps2_exit(void)
 {
 	sa1111_driver_unregister(&ps2_driver);
 }

 module_init(ps2_init);
 module_exit(ps2_exit);

 MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
 MODULE_DESCRIPTION("SA1111 PS2 controller driver");
 MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* linux/drivers/input/serio/sa1111ps2.c
	*
	* Copyright (C) 2002 Russell King
	*/
	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/input.h>
	#include <linux/serio.h>
	#include <linux/errno.h>
	#include <linux/interrupt.h>
	#include <linux/ioport.h>
	#include <linux/delay.h>
	#include <linux/device.h>
	#include <linux/slab.h>
	#include <linux/spinlock.h>

	#include <asm/io.h>

	#include <asm/hardware/sa1111.h>

	#define PS2CR 0x0000
	#define PS2STAT 0x0004
	#define PS2DATA 0x0008
	#define PS2CLKDIV 0x000c
	#define PS2PRECNT 0x0010

	#define PS2CR_ENA 0x08
	#define PS2CR_FKD 0x02
	#define PS2CR_FKC 0x01

	#define PS2STAT_STP 0x0100
	#define PS2STAT_TXE 0x0080
	#define PS2STAT_TXB 0x0040
	#define PS2STAT_RXF 0x0020
	#define PS2STAT_RXB 0x0010
	#define PS2STAT_ENA 0x0008
	#define PS2STAT_RXP 0x0004
	#define PS2STAT_KBD 0x0002
	#define PS2STAT_KBC 0x0001

	struct ps2if {
	struct serio *io;
	struct sa1111_dev *dev;
	void __iomem *base;
	int rx_irq;
	int tx_irq;
	unsigned int open;
	spinlock_t lock;
	unsigned int head;
	unsigned int tail;
	unsigned char buf[4];
	};

	/*
	* Read all bytes waiting in the PS2 port. There should be
	* at the most one, but we loop for safety. If there was a
	* framing error, we have to manually clear the status.
	*/
	static irqreturn_t ps2_rxint(int irq, void *dev_id)
	{
	struct ps2if *ps2if = dev_id;
	unsigned int scancode, flag, status;

	status = readl_relaxed(ps2if->base + PS2STAT);
	while (status & PS2STAT_RXF) {
	if (status & PS2STAT_STP)
	writel_relaxed(PS2STAT_STP, ps2if->base + PS2STAT);

	flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) \|
	(status & PS2STAT_RXP ? 0 : SERIO_PARITY);

	scancode = readl_relaxed(ps2if->base + PS2DATA) & 0xff;

	if (hweight8(scancode) & 1)
	flag ^= SERIO_PARITY;

	serio_interrupt(ps2if->io, scancode, flag);

	status = readl_relaxed(ps2if->base + PS2STAT);
	}

	return IRQ_HANDLED;
	}

	/*
	* Completion of ps2 write
	*/
	static irqreturn_t ps2_txint(int irq, void *dev_id)
	{
	struct ps2if *ps2if = dev_id;
	unsigned int status;

	spin_lock(&ps2if->lock);
	status = readl_relaxed(ps2if->base + PS2STAT);
	if (ps2if->head == ps2if->tail) {
	disable_irq_nosync(irq);
	/* done */
	} else if (status & PS2STAT_TXE) {
	writel_relaxed(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA);
	ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1);
	}
	spin_unlock(&ps2if->lock);

	return IRQ_HANDLED;
	}

	/*
	* Write a byte to the PS2 port. We have to wait for the
	* port to indicate that the transmitter is empty.
	*/
	static int ps2_write(struct serio *io, unsigned char val)
	{
	struct ps2if *ps2if = io->port_data;
	unsigned long flags;
	unsigned int head;

	spin_lock_irqsave(&ps2if->lock, flags);

	/*
	* If the TX register is empty, we can go straight out.
	*/
	if (readl_relaxed(ps2if->base + PS2STAT) & PS2STAT_TXE) {
	writel_relaxed(val, ps2if->base + PS2DATA);
	} else {
	if (ps2if->head == ps2if->tail)
	enable_irq(ps2if->tx_irq);
	head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1);
	if (head != ps2if->tail) {
	ps2if->buf[ps2if->head] = val;
	ps2if->head = head;
	}
	}

	spin_unlock_irqrestore(&ps2if->lock, flags);
	return 0;
	}

	static int ps2_open(struct serio *io)
	{
	struct ps2if *ps2if = io->port_data;
	int ret;

	ret = sa1111_enable_device(ps2if->dev);
	if (ret)
	return ret;

	ret = request_irq(ps2if->rx_irq, ps2_rxint, 0,
	SA1111_DRIVER_NAME(ps2if->dev), ps2if);
	if (ret) {
	printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
	ps2if->rx_irq, ret);
	sa1111_disable_device(ps2if->dev);
	return ret;
	}

	ret = request_irq(ps2if->tx_irq, ps2_txint, 0,
	SA1111_DRIVER_NAME(ps2if->dev), ps2if);
	if (ret) {
	printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n",
	ps2if->tx_irq, ret);
	free_irq(ps2if->rx_irq, ps2if);
	sa1111_disable_device(ps2if->dev);
	return ret;
	}

	ps2if->open = 1;

	enable_irq_wake(ps2if->rx_irq);

	writel_relaxed(PS2CR_ENA, ps2if->base + PS2CR);
	return 0;
	}

	static void ps2_close(struct serio *io)
	{
	struct ps2if *ps2if = io->port_data;

	writel_relaxed(0, ps2if->base + PS2CR);

	disable_irq_wake(ps2if->rx_irq);

	ps2if->open = 0;

	free_irq(ps2if->tx_irq, ps2if);
	free_irq(ps2if->rx_irq, ps2if);

	sa1111_disable_device(ps2if->dev);
	}

	/*
	* Clear the input buffer.
	*/
	static void ps2_clear_input(struct ps2if *ps2if)
	{
	int maxread = 100;

	while (maxread--) {
	if ((readl_relaxed(ps2if->base + PS2DATA) & 0xff) == 0xff)
	break;
	}
	}

	static unsigned int ps2_test_one(struct ps2if *ps2if,
	unsigned int mask)
	{
	unsigned int val;

	writel_relaxed(PS2CR_ENA \| mask, ps2if->base + PS2CR);

	udelay(10);

	val = readl_relaxed(ps2if->base + PS2STAT);
	return val & (PS2STAT_KBC \| PS2STAT_KBD);
	}

	/*
	* Test the keyboard interface. We basically check to make sure that
	* we can drive each line to the keyboard independently of each other.
	*/
	static int ps2_test(struct ps2if *ps2if)
	{
	unsigned int stat;
	int ret = 0;

	stat = ps2_test_one(ps2if, PS2CR_FKC);
	if (stat != PS2STAT_KBD) {
	printk("PS/2 interface test failed[1]: %02x\n", stat);
	ret = -ENODEV;
	}

	stat = ps2_test_one(ps2if, 0);
	if (stat != (PS2STAT_KBC \| PS2STAT_KBD)) {
	printk("PS/2 interface test failed[2]: %02x\n", stat);
	ret = -ENODEV;
	}

	stat = ps2_test_one(ps2if, PS2CR_FKD);
	if (stat != PS2STAT_KBC) {
	printk("PS/2 interface test failed[3]: %02x\n", stat);
	ret = -ENODEV;
	}

	writel_relaxed(0, ps2if->base + PS2CR);

	return ret;
	}

	/*
	* Add one device to this driver.
	*/
	static int ps2_probe(struct sa1111_dev *dev)
	{
	struct ps2if *ps2if;
	struct serio *serio;
	int ret;

	ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (!ps2if \|\| !serio) {
	ret = -ENOMEM;
	goto free;
	}

	serio->id.type = SERIO_8042;
	serio->write = ps2_write;
	serio->open = ps2_open;
	serio->close = ps2_close;
	strlcpy(serio->name, dev_name(&dev->dev), sizeof(serio->name));
	strlcpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys));
	serio->port_data = ps2if;
	serio->dev.parent = &dev->dev;
	ps2if->io = serio;
	ps2if->dev = dev;
	sa1111_set_drvdata(dev, ps2if);

	spin_lock_init(&ps2if->lock);

	ps2if->rx_irq = sa1111_get_irq(dev, 0);
	if (ps2if->rx_irq <= 0) {
	ret = ps2if->rx_irq ? : -ENXIO;
	goto free;
	}

	ps2if->tx_irq = sa1111_get_irq(dev, 1);
	if (ps2if->tx_irq <= 0) {
	ret = ps2if->tx_irq ? : -ENXIO;
	goto free;
	}

	/*
	* Request the physical region for this PS2 port.
	*/
	if (!request_mem_region(dev->res.start,
	dev->res.end - dev->res.start + 1,
	SA1111_DRIVER_NAME(dev))) {
	ret = -EBUSY;
	goto free;
	}

	/*
	* Our parent device has already mapped the region.
	*/
	ps2if->base = dev->mapbase;

	sa1111_enable_device(ps2if->dev);

	/* Incoming clock is 8MHz */
	writel_relaxed(0, ps2if->base + PS2CLKDIV);
	writel_relaxed(127, ps2if->base + PS2PRECNT);

	/*
	* Flush any pending input.
	*/
	ps2_clear_input(ps2if);

	/*
	* Test the keyboard interface.
	*/
	ret = ps2_test(ps2if);
	if (ret)
	goto out;

	/*
	* Flush any pending input.
	*/
	ps2_clear_input(ps2if);

	sa1111_disable_device(ps2if->dev);
	serio_register_port(ps2if->io);
	return 0;

	out:
	sa1111_disable_device(ps2if->dev);
	release_mem_region(dev->res.start, resource_size(&dev->res));
	free:
	sa1111_set_drvdata(dev, NULL);
	kfree(ps2if);
	kfree(serio);
	return ret;
	}

	/*
	* Remove one device from this driver.
	*/
	static void ps2_remove(struct sa1111_dev *dev)
	{
	struct ps2if *ps2if = sa1111_get_drvdata(dev);

	serio_unregister_port(ps2if->io);
	release_mem_region(dev->res.start, resource_size(&dev->res));
	sa1111_set_drvdata(dev, NULL);

	kfree(ps2if);
	}

	/*
	* Our device driver structure
	*/
	static struct sa1111_driver ps2_driver = {
	.drv = {
	.name = "sa1111-ps2",
	.owner = THIS_MODULE,
	},
	.devid = SA1111_DEVID_PS2,
	.probe = ps2_probe,
	.remove = ps2_remove,
	};

	static int __init ps2_init(void)
	{
	return sa1111_driver_register(&ps2_driver);
	}

	static void __exit ps2_exit(void)
	{
	sa1111_driver_unregister(&ps2_driver);
	}

	module_init(ps2_init);
	module_exit(ps2_exit);

	MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>");
	MODULE_DESCRIPTION("SA1111 PS2 controller driver");
	MODULE_LICENSE("GPL");