// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright (C) 2013 Aeroflex Gaisler * * This driver supports the APBPS2 PS/2 core available in the GRLIB * VHDL IP core library. * * Full documentation of the APBPS2 core can be found here: * http://www.gaisler.com/products/grlib/grip.pdf * * See "Documentation/devicetree/bindings/input/ps2keyb-mouse-apbps2.txt" for * information on open firmware properties. * * Contributors: Daniel Hellstrom <daniel@gaisler.com> */#include <linux/platform_device.h>#include <linux/module.h>#include <linux/serio.h>#include <linux/errno.h>#include <linux/interrupt.h>#include <linux/of.h>#include <linux/of_irq.h>#include <linux/device.h>#include <linux/delay.h>#include <linux/err.h>#include <linux/slab.h>#include <linux/string.h>#include <linux/kernel.h>#include <linux/io.h> struct apbps2_regs {	u32 __iomem data;	/* 0x00 */	u32 __iomem status;	/* 0x04 */	u32 __iomem ctrl;	/* 0x08 */	u32 __iomem reload;	/* 0x0c */}; #define APBPS2_STATUS_DR	(1<<0)#define APBPS2_STATUS_PE	(1<<1)#define APBPS2_STATUS_FE	(1<<2)#define APBPS2_STATUS_KI	(1<<3)#define APBPS2_STATUS_RF	(1<<4)#define APBPS2_STATUS_TF	(1<<5)#define APBPS2_STATUS_TCNT	(0x1f<<22)#define APBPS2_STATUS_RCNT	(0x1f<<27) #define APBPS2_CTRL_RE		(1<<0)#define APBPS2_CTRL_TE		(1<<1)#define APBPS2_CTRL_RI		(1<<2)#define APBPS2_CTRL_TI		(1<<3) struct apbps2_priv {	struct serio		*io;	struct apbps2_regs	__iomem *regs;}; static int apbps2_idx; static irqreturn_t apbps2_isr(int irq, void *dev_id){	struct apbps2_priv *priv = dev_id;	unsigned long status, data, rxflags;	irqreturn_t ret = IRQ_NONE; 	while ((status = ioread32be(&priv->regs->status)) & APBPS2_STATUS_DR) {		data = ioread32be(&priv->regs->data);		rxflags = (status & APBPS2_STATUS_PE) ? SERIO_PARITY : 0;		rxflags |= (status & APBPS2_STATUS_FE) ? SERIO_FRAME : 0; 		/* Clear error bits */		if (rxflags)			iowrite32be(0, &priv->regs->status); 		serio_interrupt(priv->io, data, rxflags); 		ret = IRQ_HANDLED;	} 	return ret;} static int apbps2_write(struct serio *io, unsigned char val){	struct apbps2_priv *priv = io->port_data;	unsigned int tleft = 10000; /* Timeout in 100ms */ 	/* Delay until PS/2 controller has room for more chars */	while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) && tleft--)		udelay(10); 	if ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) == 0) {		iowrite32be(val, &priv->regs->data); 		iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI | APBPS2_CTRL_TE,				&priv->regs->ctrl);		return 0;	} 	return -ETIMEDOUT;} static int apbps2_open(struct serio *io){	struct apbps2_priv *priv = io->port_data;	int limit; 	/* Clear error flags */	iowrite32be(0, &priv->regs->status); 	/* Clear old data if available (unlikely) */	limit = 1024;	while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_DR) && --limit)		ioread32be(&priv->regs->data); 	/* Enable receiver and its interrupt */	iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI, &priv->regs->ctrl); 	return 0;} static void apbps2_close(struct serio *io){	struct apbps2_priv *priv = io->port_data; 	/* Stop interrupts at PS/2 HW level */	iowrite32be(0, &priv->regs->ctrl);} /* Initialize one APBPS2 PS/2 core */static int apbps2_of_probe(struct platform_device *ofdev){	struct apbps2_priv *priv;	int irq, err;	u32 freq_hz; 	priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL);	if (!priv) {		dev_err(&ofdev->dev, "memory allocation failed\n");		return -ENOMEM;	} 	/* Find device address */	priv->regs = devm_platform_ioremap_resource(ofdev, 0);	if (IS_ERR(priv->regs))		return PTR_ERR(priv->regs); 	/* Reset hardware, disable interrupt */	iowrite32be(0, &priv->regs->ctrl); 	/* IRQ */	irq = platform_get_irq(ofdev, 0);	if (irq < 0)		return irq; 	err = devm_request_irq(&ofdev->dev, irq, apbps2_isr,				IRQF_SHARED, "apbps2", priv);	if (err) {		dev_err(&ofdev->dev, "request IRQ%d failed\n", irq);		return err;	} 	/* Get core frequency */	if (of_property_read_u32(ofdev->dev.of_node, "freq", &freq_hz)) {		dev_err(&ofdev->dev, "unable to get core frequency\n");		return -EINVAL;	} 	/* Set reload register to core freq in kHz/10 */	iowrite32be(freq_hz / 10000, &priv->regs->reload); 	priv->io = kzalloc_obj(*priv->io);	if (!priv->io)		return -ENOMEM; 	priv->io->id.type = SERIO_8042;	priv->io->open = apbps2_open;	priv->io->close = apbps2_close;	priv->io->write = apbps2_write;	priv->io->port_data = priv;	strscpy(priv->io->name, "APBPS2 PS/2", sizeof(priv->io->name));	snprintf(priv->io->phys, sizeof(priv->io->phys),		 "apbps2_%d", apbps2_idx++); 	dev_info(&ofdev->dev, "irq = %d, base = 0x%p\n", irq, priv->regs); 	serio_register_port(priv->io); 	platform_set_drvdata(ofdev, priv); 	return 0;} static void apbps2_of_remove(struct platform_device *of_dev){	struct apbps2_priv *priv = platform_get_drvdata(of_dev); 	serio_unregister_port(priv->io);} static const struct of_device_id apbps2_of_match[] = {	{ .name = "GAISLER_APBPS2", },	{ .name = "01_060", },	{}}; MODULE_DEVICE_TABLE(of, apbps2_of_match); static struct platform_driver apbps2_of_driver = {	.driver = {		.name = "grlib-apbps2",		.of_match_table = apbps2_of_match,	},	.probe = apbps2_of_probe,	.remove = apbps2_of_remove,}; module_platform_driver(apbps2_of_driver); MODULE_AUTHOR("Aeroflex Gaisler AB.");MODULE_DESCRIPTION("GRLIB APBPS2 PS/2 serial I/O");MODULE_LICENSE("GPL");