drivers/input/serio/sun4i-ps2.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *	Driver for Allwinner A10 PS2 host controller
  *
  *	Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
  *		Aaron.maoye <leafy.myeh@newbietech.com>
  */

 #include <linux/module.h>
 #include <linux/serio.h>
 #include <linux/interrupt.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/io.h>
 #include <linux/clk.h>
 #include <linux/mod_devicetable.h>
 #include <linux/platform_device.h>

 #define DRIVER_NAME		"sun4i-ps2"

 /* register offset definitions */
 #define PS2_REG_GCTL		0x00	/* PS2 Module Global Control Reg */
 #define PS2_REG_DATA		0x04	/* PS2 Module Data Reg		*/
 #define PS2_REG_LCTL		0x08	/* PS2 Module Line Control Reg */
 #define PS2_REG_LSTS		0x0C	/* PS2 Module Line Status Reg	*/
 #define PS2_REG_FCTL		0x10	/* PS2 Module FIFO Control Reg */
 #define PS2_REG_FSTS		0x14	/* PS2 Module FIFO Status Reg	*/
 #define PS2_REG_CLKDR		0x18	/* PS2 Module Clock Divider Reg*/

 /*  PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
 #define PS2_GCTL_INTFLAG	BIT(4)
 #define PS2_GCTL_INTEN		BIT(3)
 #define PS2_GCTL_RESET		BIT(2)
 #define PS2_GCTL_MASTER		BIT(1)
 #define PS2_GCTL_BUSEN		BIT(0)

 /* PS2 LINE CONTROL REGISTER */
 #define PS2_LCTL_NOACK		BIT(18)
 #define PS2_LCTL_TXDTOEN	BIT(8)
 #define PS2_LCTL_STOPERREN	BIT(3)
 #define PS2_LCTL_ACKERREN	BIT(2)
 #define PS2_LCTL_PARERREN	BIT(1)
 #define PS2_LCTL_RXDTOEN	BIT(0)

 /* PS2 LINE STATUS REGISTER */
 #define PS2_LSTS_TXTDO		BIT(8)
 #define PS2_LSTS_STOPERR	BIT(3)
 #define PS2_LSTS_ACKERR		BIT(2)
 #define PS2_LSTS_PARERR		BIT(1)
 #define PS2_LSTS_RXTDO		BIT(0)

 #define PS2_LINE_ERROR_BIT \
 	(PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR | \
 	PS2_LSTS_PARERR | PS2_LSTS_RXTDO)

 /* PS2 FIFO CONTROL REGISTER */
 #define PS2_FCTL_TXRST		BIT(17)
 #define PS2_FCTL_RXRST		BIT(16)
 #define PS2_FCTL_TXUFIEN	BIT(10)
 #define PS2_FCTL_TXOFIEN	BIT(9)
 #define PS2_FCTL_TXRDYIEN	BIT(8)
 #define PS2_FCTL_RXUFIEN	BIT(2)
 #define PS2_FCTL_RXOFIEN	BIT(1)
 #define PS2_FCTL_RXRDYIEN	BIT(0)

 /* PS2 FIFO STATUS REGISTER */
 #define PS2_FSTS_TXUF		BIT(10)
 #define PS2_FSTS_TXOF		BIT(9)
 #define PS2_FSTS_TXRDY		BIT(8)
 #define PS2_FSTS_RXUF		BIT(2)
 #define PS2_FSTS_RXOF		BIT(1)
 #define PS2_FSTS_RXRDY		BIT(0)

 #define PS2_FIFO_ERROR_BIT \
 	(PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_RXUF | PS2_FSTS_RXOF)

 #define PS2_SAMPLE_CLK		1000000
 #define PS2_SCLK		125000

 struct sun4i_ps2data {
 	struct serio *serio;
 	struct device *dev;

 	/* IO mapping base */
 	void __iomem	*reg_base;

 	/* clock management */
 	struct clk	*clk;

 	/* irq */
 	spinlock_t	lock;
 	int		irq;
 };

 static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
 {
 	struct sun4i_ps2data *drvdata = dev_id;
 	u32 intr_status;
 	u32 fifo_status;
 	unsigned char byte;
 	unsigned int rxflags = 0;
 	u32 rval;

 	spin_lock(&drvdata->lock);

 	/* Get the PS/2 interrupts and clear them */
 	intr_status  = readl(drvdata->reg_base + PS2_REG_LSTS);
 	fifo_status  = readl(drvdata->reg_base + PS2_REG_FSTS);

 	/* Check line status register */
 	if (intr_status & PS2_LINE_ERROR_BIT) {
 		rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
 		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
 		rxflags |= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;

 		rval = PS2_LSTS_TXTDO | PS2_LSTS_STOPERR | PS2_LSTS_ACKERR |
 			PS2_LSTS_PARERR | PS2_LSTS_RXTDO;
 		writel(rval, drvdata->reg_base + PS2_REG_LSTS);
 	}

 	/* Check FIFO status register */
 	if (fifo_status & PS2_FIFO_ERROR_BIT) {
 		rval = PS2_FSTS_TXUF | PS2_FSTS_TXOF | PS2_FSTS_TXRDY |
 			PS2_FSTS_RXUF | PS2_FSTS_RXOF | PS2_FSTS_RXRDY;
 		writel(rval, drvdata->reg_base + PS2_REG_FSTS);
 	}

 	rval = (fifo_status >> 16) & 0x3;
 	while (rval--) {
 		byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
 		serio_interrupt(drvdata->serio, byte, rxflags);
 	}

 	writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
 	writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);

 	spin_unlock(&drvdata->lock);

 	return IRQ_HANDLED;
 }

 static int sun4i_ps2_open(struct serio *serio)
 {
 	struct sun4i_ps2data *drvdata = serio->port_data;
 	u32 src_clk = 0;
 	u32 clk_scdf;
 	u32 clk_pcdf;
 	u32 rval;
 	unsigned long flags;

 	/* Set line control and enable interrupt */
 	rval = PS2_LCTL_STOPERREN | PS2_LCTL_ACKERREN
 		| PS2_LCTL_PARERREN | PS2_LCTL_RXDTOEN;
 	writel(rval, drvdata->reg_base + PS2_REG_LCTL);

 	/* Reset FIFO */
 	rval = PS2_FCTL_TXRST | PS2_FCTL_RXRST | PS2_FCTL_TXUFIEN
 		| PS2_FCTL_TXOFIEN | PS2_FCTL_RXUFIEN
 		| PS2_FCTL_RXOFIEN | PS2_FCTL_RXRDYIEN;

 	writel(rval, drvdata->reg_base + PS2_REG_FCTL);

 	src_clk = clk_get_rate(drvdata->clk);
 	/* Set clock divider register */
 	clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
 	clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
 	rval = (clk_scdf << 8) | clk_pcdf;
 	writel(rval, drvdata->reg_base + PS2_REG_CLKDR);

 	/* Set global control register */
 	rval = PS2_GCTL_RESET | PS2_GCTL_INTEN | PS2_GCTL_MASTER
 		| PS2_GCTL_BUSEN;

 	spin_lock_irqsave(&drvdata->lock, flags);
 	writel(rval, drvdata->reg_base + PS2_REG_GCTL);
 	spin_unlock_irqrestore(&drvdata->lock, flags);

 	return 0;
 }

 static void sun4i_ps2_close(struct serio *serio)
 {
 	struct sun4i_ps2data *drvdata = serio->port_data;
 	u32 rval;

 	/* Shut off the interrupt */
 	rval = readl(drvdata->reg_base + PS2_REG_GCTL);
 	writel(rval & ~(PS2_GCTL_INTEN), drvdata->reg_base + PS2_REG_GCTL);

 	synchronize_irq(drvdata->irq);
 }

 static int sun4i_ps2_write(struct serio *serio, unsigned char val)
 {
 	unsigned long expire = jiffies + msecs_to_jiffies(10000);
 	struct sun4i_ps2data *drvdata = serio->port_data;

 	do {
 		if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
 			writel(val, drvdata->reg_base + PS2_REG_DATA);
 			return 0;
 		}
 	} while (time_before(jiffies, expire));

 	return SERIO_TIMEOUT;
 }

 static int sun4i_ps2_probe(struct platform_device *pdev)
 {
 	struct resource *res; /* IO mem resources */
 	struct sun4i_ps2data *drvdata;
 	struct serio *serio;
 	struct device *dev = &pdev->dev;
 	int error;

 	drvdata = kzalloc(sizeof(struct sun4i_ps2data), GFP_KERNEL);
 	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
 	if (!drvdata || !serio) {
 		error = -ENOMEM;
 		goto err_free_mem;
 	}

 	spin_lock_init(&drvdata->lock);

 	/* IO */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res) {
 		dev_err(dev, "failed to locate registers\n");
 		error = -ENXIO;
 		goto err_free_mem;
 	}

 	drvdata->reg_base = ioremap(res->start, resource_size(res));
 	if (!drvdata->reg_base) {
 		dev_err(dev, "failed to map registers\n");
 		error = -ENOMEM;
 		goto err_free_mem;
 	}

 	drvdata->clk = clk_get(dev, NULL);
 	if (IS_ERR(drvdata->clk)) {
 		error = PTR_ERR(drvdata->clk);
 		dev_err(dev, "couldn't get clock %d\n", error);
 		goto err_ioremap;
 	}

 	error = clk_prepare_enable(drvdata->clk);
 	if (error) {
 		dev_err(dev, "failed to enable clock %d\n", error);
 		goto err_clk;
 	}

 	serio->id.type = SERIO_8042;
 	serio->write = sun4i_ps2_write;
 	serio->open = sun4i_ps2_open;
 	serio->close = sun4i_ps2_close;
 	serio->port_data = drvdata;
 	serio->dev.parent = dev;
 	strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
 	strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));

 	/* shutoff interrupt */
 	writel(0, drvdata->reg_base + PS2_REG_GCTL);

 	/* Get IRQ for the device */
 	drvdata->irq = platform_get_irq(pdev, 0);
 	if (drvdata->irq < 0) {
 		error = drvdata->irq;
 		goto err_disable_clk;
 	}

 	drvdata->serio = serio;
 	drvdata->dev = dev;

 	error = request_irq(drvdata->irq, sun4i_ps2_interrupt, 0,
 			    DRIVER_NAME, drvdata);
 	if (error) {
 		dev_err(drvdata->dev, "failed to allocate interrupt %d: %d\n",
 			drvdata->irq, error);
 		goto err_disable_clk;
 	}

 	serio_register_port(serio);
 	platform_set_drvdata(pdev, drvdata);

 	return 0;	/* success */

 err_disable_clk:
 	clk_disable_unprepare(drvdata->clk);
 err_clk:
 	clk_put(drvdata->clk);
 err_ioremap:
 	iounmap(drvdata->reg_base);
 err_free_mem:
 	kfree(serio);
 	kfree(drvdata);
 	return error;
 }

 static int sun4i_ps2_remove(struct platform_device *pdev)
 {
 	struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);

 	serio_unregister_port(drvdata->serio);

 	free_irq(drvdata->irq, drvdata);

 	clk_disable_unprepare(drvdata->clk);
 	clk_put(drvdata->clk);

 	iounmap(drvdata->reg_base);

 	kfree(drvdata);

 	return 0;
 }

 static const struct of_device_id sun4i_ps2_match[] = {
 	{ .compatible = "allwinner,sun4i-a10-ps2", },
 	{ },
 };

 MODULE_DEVICE_TABLE(of, sun4i_ps2_match);

 static struct platform_driver sun4i_ps2_driver = {
 	.probe		= sun4i_ps2_probe,
 	.remove		= sun4i_ps2_remove,
 	.driver = {
 		.name = DRIVER_NAME,
 		.of_match_table = sun4i_ps2_match,
 	},
 };
 module_platform_driver(sun4i_ps2_driver);

 MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
 MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
 MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Driver for Allwinner A10 PS2 host controller
	*
	* Author: Vishnu Patekar <vishnupatekar0510@gmail.com>
	* Aaron.maoye <leafy.myeh@newbietech.com>
	*/

	#include <linux/module.h>
	#include <linux/serio.h>
	#include <linux/interrupt.h>
	#include <linux/errno.h>
	#include <linux/slab.h>
	#include <linux/io.h>
	#include <linux/clk.h>
	#include <linux/mod_devicetable.h>
	#include <linux/platform_device.h>

	#define DRIVER_NAME "sun4i-ps2"

	/* register offset definitions */
	#define PS2_REG_GCTL 0x00 /* PS2 Module Global Control Reg */
	#define PS2_REG_DATA 0x04 /* PS2 Module Data Reg */
	#define PS2_REG_LCTL 0x08 /* PS2 Module Line Control Reg */
	#define PS2_REG_LSTS 0x0C /* PS2 Module Line Status Reg */
	#define PS2_REG_FCTL 0x10 /* PS2 Module FIFO Control Reg */
	#define PS2_REG_FSTS 0x14 /* PS2 Module FIFO Status Reg */
	#define PS2_REG_CLKDR 0x18 /* PS2 Module Clock Divider Reg*/

	/* PS2 GLOBAL CONTROL REGISTER PS2_GCTL */
	#define PS2_GCTL_INTFLAG BIT(4)
	#define PS2_GCTL_INTEN BIT(3)
	#define PS2_GCTL_RESET BIT(2)
	#define PS2_GCTL_MASTER BIT(1)
	#define PS2_GCTL_BUSEN BIT(0)

	/* PS2 LINE CONTROL REGISTER */
	#define PS2_LCTL_NOACK BIT(18)
	#define PS2_LCTL_TXDTOEN BIT(8)
	#define PS2_LCTL_STOPERREN BIT(3)
	#define PS2_LCTL_ACKERREN BIT(2)
	#define PS2_LCTL_PARERREN BIT(1)
	#define PS2_LCTL_RXDTOEN BIT(0)

	/* PS2 LINE STATUS REGISTER */
	#define PS2_LSTS_TXTDO BIT(8)
	#define PS2_LSTS_STOPERR BIT(3)
	#define PS2_LSTS_ACKERR BIT(2)
	#define PS2_LSTS_PARERR BIT(1)
	#define PS2_LSTS_RXTDO BIT(0)

	#define PS2_LINE_ERROR_BIT \
	(PS2_LSTS_TXTDO \| PS2_LSTS_STOPERR \| PS2_LSTS_ACKERR \| \
	PS2_LSTS_PARERR \| PS2_LSTS_RXTDO)

	/* PS2 FIFO CONTROL REGISTER */
	#define PS2_FCTL_TXRST BIT(17)
	#define PS2_FCTL_RXRST BIT(16)
	#define PS2_FCTL_TXUFIEN BIT(10)
	#define PS2_FCTL_TXOFIEN BIT(9)
	#define PS2_FCTL_TXRDYIEN BIT(8)
	#define PS2_FCTL_RXUFIEN BIT(2)
	#define PS2_FCTL_RXOFIEN BIT(1)
	#define PS2_FCTL_RXRDYIEN BIT(0)

	/* PS2 FIFO STATUS REGISTER */
	#define PS2_FSTS_TXUF BIT(10)
	#define PS2_FSTS_TXOF BIT(9)
	#define PS2_FSTS_TXRDY BIT(8)
	#define PS2_FSTS_RXUF BIT(2)
	#define PS2_FSTS_RXOF BIT(1)
	#define PS2_FSTS_RXRDY BIT(0)

	#define PS2_FIFO_ERROR_BIT \
	(PS2_FSTS_TXUF \| PS2_FSTS_TXOF \| PS2_FSTS_RXUF \| PS2_FSTS_RXOF)

	#define PS2_SAMPLE_CLK 1000000
	#define PS2_SCLK 125000

	struct sun4i_ps2data {
	struct serio *serio;
	struct device *dev;

	/* IO mapping base */
	void __iomem *reg_base;

	/* clock management */
	struct clk *clk;

	/* irq */
	spinlock_t lock;
	int irq;
	};

	static irqreturn_t sun4i_ps2_interrupt(int irq, void *dev_id)
	{
	struct sun4i_ps2data *drvdata = dev_id;
	u32 intr_status;
	u32 fifo_status;
	unsigned char byte;
	unsigned int rxflags = 0;
	u32 rval;

	spin_lock(&drvdata->lock);

	/* Get the PS/2 interrupts and clear them */
	intr_status = readl(drvdata->reg_base + PS2_REG_LSTS);
	fifo_status = readl(drvdata->reg_base + PS2_REG_FSTS);

	/* Check line status register */
	if (intr_status & PS2_LINE_ERROR_BIT) {
	rxflags = (intr_status & PS2_LINE_ERROR_BIT) ? SERIO_FRAME : 0;
	rxflags \|= (intr_status & PS2_LSTS_PARERR) ? SERIO_PARITY : 0;
	rxflags \|= (intr_status & PS2_LSTS_PARERR) ? SERIO_TIMEOUT : 0;

	rval = PS2_LSTS_TXTDO \| PS2_LSTS_STOPERR \| PS2_LSTS_ACKERR \|
	PS2_LSTS_PARERR \| PS2_LSTS_RXTDO;
	writel(rval, drvdata->reg_base + PS2_REG_LSTS);
	}

	/* Check FIFO status register */
	if (fifo_status & PS2_FIFO_ERROR_BIT) {
	rval = PS2_FSTS_TXUF \| PS2_FSTS_TXOF \| PS2_FSTS_TXRDY \|
	PS2_FSTS_RXUF \| PS2_FSTS_RXOF \| PS2_FSTS_RXRDY;
	writel(rval, drvdata->reg_base + PS2_REG_FSTS);
	}

	rval = (fifo_status >> 16) & 0x3;
	while (rval--) {
	byte = readl(drvdata->reg_base + PS2_REG_DATA) & 0xff;
	serio_interrupt(drvdata->serio, byte, rxflags);
	}

	writel(intr_status, drvdata->reg_base + PS2_REG_LSTS);
	writel(fifo_status, drvdata->reg_base + PS2_REG_FSTS);

	spin_unlock(&drvdata->lock);

	return IRQ_HANDLED;
	}

	static int sun4i_ps2_open(struct serio *serio)
	{
	struct sun4i_ps2data *drvdata = serio->port_data;
	u32 src_clk = 0;
	u32 clk_scdf;
	u32 clk_pcdf;
	u32 rval;
	unsigned long flags;

	/* Set line control and enable interrupt */
	rval = PS2_LCTL_STOPERREN \| PS2_LCTL_ACKERREN
	\| PS2_LCTL_PARERREN \| PS2_LCTL_RXDTOEN;
	writel(rval, drvdata->reg_base + PS2_REG_LCTL);

	/* Reset FIFO */
	rval = PS2_FCTL_TXRST \| PS2_FCTL_RXRST \| PS2_FCTL_TXUFIEN
	\| PS2_FCTL_TXOFIEN \| PS2_FCTL_RXUFIEN
	\| PS2_FCTL_RXOFIEN \| PS2_FCTL_RXRDYIEN;

	writel(rval, drvdata->reg_base + PS2_REG_FCTL);

	src_clk = clk_get_rate(drvdata->clk);
	/* Set clock divider register */
	clk_scdf = src_clk / PS2_SAMPLE_CLK - 1;
	clk_pcdf = PS2_SAMPLE_CLK / PS2_SCLK - 1;
	rval = (clk_scdf << 8) \| clk_pcdf;
	writel(rval, drvdata->reg_base + PS2_REG_CLKDR);

	/* Set global control register */
	rval = PS2_GCTL_RESET \| PS2_GCTL_INTEN \| PS2_GCTL_MASTER
	\| PS2_GCTL_BUSEN;

	spin_lock_irqsave(&drvdata->lock, flags);
	writel(rval, drvdata->reg_base + PS2_REG_GCTL);
	spin_unlock_irqrestore(&drvdata->lock, flags);

	return 0;
	}

	static void sun4i_ps2_close(struct serio *serio)
	{
	struct sun4i_ps2data *drvdata = serio->port_data;
	u32 rval;

	/* Shut off the interrupt */
	rval = readl(drvdata->reg_base + PS2_REG_GCTL);
	writel(rval & ~(PS2_GCTL_INTEN), drvdata->reg_base + PS2_REG_GCTL);

	synchronize_irq(drvdata->irq);
	}

	static int sun4i_ps2_write(struct serio *serio, unsigned char val)
	{
	unsigned long expire = jiffies + msecs_to_jiffies(10000);
	struct sun4i_ps2data *drvdata = serio->port_data;

	do {
	if (readl(drvdata->reg_base + PS2_REG_FSTS) & PS2_FSTS_TXRDY) {
	writel(val, drvdata->reg_base + PS2_REG_DATA);
	return 0;
	}
	} while (time_before(jiffies, expire));

	return SERIO_TIMEOUT;
	}

	static int sun4i_ps2_probe(struct platform_device *pdev)
	{
	struct resource res; / IO mem resources */
	struct sun4i_ps2data *drvdata;
	struct serio *serio;
	struct device *dev = &pdev->dev;
	int error;

	drvdata = kzalloc(sizeof(struct sun4i_ps2data), GFP_KERNEL);
	serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
	if (!drvdata \|\| !serio) {
	error = -ENOMEM;
	goto err_free_mem;
	}

	spin_lock_init(&drvdata->lock);

	/* IO */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
	dev_err(dev, "failed to locate registers\n");
	error = -ENXIO;
	goto err_free_mem;
	}

	drvdata->reg_base = ioremap(res->start, resource_size(res));
	if (!drvdata->reg_base) {
	dev_err(dev, "failed to map registers\n");
	error = -ENOMEM;
	goto err_free_mem;
	}

	drvdata->clk = clk_get(dev, NULL);
	if (IS_ERR(drvdata->clk)) {
	error = PTR_ERR(drvdata->clk);
	dev_err(dev, "couldn't get clock %d\n", error);
	goto err_ioremap;
	}

	error = clk_prepare_enable(drvdata->clk);
	if (error) {
	dev_err(dev, "failed to enable clock %d\n", error);
	goto err_clk;
	}

	serio->id.type = SERIO_8042;
	serio->write = sun4i_ps2_write;
	serio->open = sun4i_ps2_open;
	serio->close = sun4i_ps2_close;
	serio->port_data = drvdata;
	serio->dev.parent = dev;
	strlcpy(serio->name, dev_name(dev), sizeof(serio->name));
	strlcpy(serio->phys, dev_name(dev), sizeof(serio->phys));

	/* shutoff interrupt */
	writel(0, drvdata->reg_base + PS2_REG_GCTL);

	/* Get IRQ for the device */
	drvdata->irq = platform_get_irq(pdev, 0);
	if (drvdata->irq < 0) {
	error = drvdata->irq;
	goto err_disable_clk;
	}

	drvdata->serio = serio;
	drvdata->dev = dev;

	error = request_irq(drvdata->irq, sun4i_ps2_interrupt, 0,
	DRIVER_NAME, drvdata);
	if (error) {
	dev_err(drvdata->dev, "failed to allocate interrupt %d: %d\n",
	drvdata->irq, error);
	goto err_disable_clk;
	}

	serio_register_port(serio);
	platform_set_drvdata(pdev, drvdata);

	return 0; /* success */

	err_disable_clk:
	clk_disable_unprepare(drvdata->clk);
	err_clk:
	clk_put(drvdata->clk);
	err_ioremap:
	iounmap(drvdata->reg_base);
	err_free_mem:
	kfree(serio);
	kfree(drvdata);
	return error;
	}

	static int sun4i_ps2_remove(struct platform_device *pdev)
	{
	struct sun4i_ps2data *drvdata = platform_get_drvdata(pdev);

	serio_unregister_port(drvdata->serio);

	free_irq(drvdata->irq, drvdata);

	clk_disable_unprepare(drvdata->clk);
	clk_put(drvdata->clk);

	iounmap(drvdata->reg_base);

	kfree(drvdata);

	return 0;
	}

	static const struct of_device_id sun4i_ps2_match[] = {
	{ .compatible = "allwinner,sun4i-a10-ps2", },
	{ },
	};

	MODULE_DEVICE_TABLE(of, sun4i_ps2_match);

	static struct platform_driver sun4i_ps2_driver = {
	.probe = sun4i_ps2_probe,
	.remove = sun4i_ps2_remove,
	.driver = {
	.name = DRIVER_NAME,
	.of_match_table = sun4i_ps2_match,
	},
	};
	module_platform_driver(sun4i_ps2_driver);

	MODULE_AUTHOR("Vishnu Patekar <vishnupatekar0510@gmail.com>");
	MODULE_AUTHOR("Aaron.maoye <leafy.myeh@newbietech.com>");
	MODULE_DESCRIPTION("Allwinner A10/Sun4i PS/2 driver");
	MODULE_LICENSE("GPL v2");