Input: add new serio driver for Xilinx XPS PS2 IP

Added a new driver for Xilinx XPS PS2 IP. This driver is
a flat driver to better match the Linux driver pattern.

Signed-off-by: Sadanand <sadanan@xilinx.com>
Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 380 insertions, 0 deletions

diff --git a/drivers/input/serio/xilinx_ps2.c b/drivers/input/serio/xilinx_ps2.c
new file mode 100644
index 000000000000..0ed044d5e685
--- /dev/null
+++ b/drivers/input/serio/xilinx_ps2.c
@@ -0,0 +1,380 @@
+/*
+ * Xilinx XPS PS/2 device driver
+ *
+ * (c) 2005 MontaVista Software, Inc.
+ * (c) 2008 Xilinx, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+
+#include <linux/module.h>
+#include <linux/serio.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/io.h>
+
+#include <linux/of_device.h>
+#include <linux/of_platform.h>
+
+#define DRIVER_NAME		"xilinx_ps2"
+
+/* Register offsets for the xps2 device */
+#define XPS2_SRST_OFFSET	0x00000000 /* Software Reset register */
+#define XPS2_STATUS_OFFSET	0x00000004 /* Status register */
+#define XPS2_RX_DATA_OFFSET	0x00000008 /* Receive Data register */
+#define XPS2_TX_DATA_OFFSET	0x0000000C /* Transmit Data register */
+#define XPS2_GIER_OFFSET	0x0000002C /* Global Interrupt Enable reg */
+#define XPS2_IPISR_OFFSET	0x00000030 /* Interrupt Status register */
+#define XPS2_IPIER_OFFSET	0x00000038 /* Interrupt Enable register */
+
+/* Reset Register Bit Definitions */
+#define XPS2_SRST_RESET		0x0000000A /* Software Reset  */
+
+/* Status Register Bit Positions */
+#define XPS2_STATUS_RX_FULL	0x00000001 /* Receive Full  */
+#define XPS2_STATUS_TX_FULL	0x00000002 /* Transmit Full  */
+
+/* Bit definitions for ISR/IER registers. Both the registers have the same bit
+ * definitions and are only defined once. */
+#define XPS2_IPIXR_WDT_TOUT	0x00000001 /* Watchdog Timeout Interrupt */
+#define XPS2_IPIXR_TX_NOACK	0x00000002 /* Transmit No ACK Interrupt */
+#define XPS2_IPIXR_TX_ACK	0x00000004 /* Transmit ACK (Data) Interrupt */
+#define XPS2_IPIXR_RX_OVF	0x00000008 /* Receive Overflow Interrupt */
+#define XPS2_IPIXR_RX_ERR	0x00000010 /* Receive Error Interrupt */
+#define XPS2_IPIXR_RX_FULL	0x00000020 /* Receive Data Interrupt */
+
+/* Mask for all the Transmit Interrupts */
+#define XPS2_IPIXR_TX_ALL	(XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_TX_ACK)
+
+/* Mask for all the Receive Interrupts */
+#define XPS2_IPIXR_RX_ALL	(XPS2_IPIXR_RX_OVF | XPS2_IPIXR_RX_ERR |  \
+					XPS2_IPIXR_RX_FULL)
+
+/* Mask for all the Interrupts */
+#define XPS2_IPIXR_ALL		(XPS2_IPIXR_TX_ALL | XPS2_IPIXR_RX_ALL |  \
+					XPS2_IPIXR_WDT_TOUT)
+
+/* Global Interrupt Enable mask */
+#define XPS2_GIER_GIE_MASK	0x80000000
+
+struct xps2data {
+	int irq;
+	u32 phys_addr;
+	u32 remap_size;
+	spinlock_t lock;
+	u8 rxb;				/* Rx buffer */
+	void __iomem *base_address;	/* virt. address of control registers */
+	unsigned int dfl;
+	struct serio serio;		/* serio */
+};
+
+/************************************/
+/* XPS PS/2 data transmission calls */
+/************************************/
+
+/*
+ * xps2_recv() will attempt to receive a byte of data from the PS/2 port.
+ */
+static int xps2_recv(struct xps2data *drvdata, u8 *byte)
+{
+	u32 sr;
+	int status = -1;
+
+	/* If there is data available in the PS/2 receiver, read it */
+	sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
+	if (sr & XPS2_STATUS_RX_FULL) {
+		*byte = in_be32(drvdata->base_address + XPS2_RX_DATA_OFFSET);
+		status = 0;
+	}
+
+	return status;
+}
+
+/*********************/
+/* Interrupt handler */
+/*********************/
+static irqreturn_t xps2_interrupt(int irq, void *dev_id)
+{
+	struct xps2data *drvdata = dev_id;
+	u32 intr_sr;
+	u8 c;
+	int status;
+
+	/* Get the PS/2 interrupts and clear them */
+	intr_sr = in_be32(drvdata->base_address + XPS2_IPISR_OFFSET);
+	out_be32(drvdata->base_address + XPS2_IPISR_OFFSET, intr_sr);
+
+	/* Check which interrupt is active */
+	if (intr_sr & XPS2_IPIXR_RX_OVF)
+		printk(KERN_WARNING "%s: receive overrun error\n",
+			drvdata->serio.name);
+
+	if (intr_sr & XPS2_IPIXR_RX_ERR)
+		drvdata->dfl |= SERIO_PARITY;
+
+	if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT))
+		drvdata->dfl |= SERIO_TIMEOUT;
+
+	if (intr_sr & XPS2_IPIXR_RX_FULL) {
+		status = xps2_recv(drvdata, &drvdata->rxb);
+
+		/* Error, if a byte is not received */
+		if (status) {
+			printk(KERN_ERR
+				"%s: wrong rcvd byte count (%d)\n",
+				drvdata->serio.name, status);
+		} else {
+			c = drvdata->rxb;
+			serio_interrupt(&drvdata->serio, c, drvdata->dfl);
+			drvdata->dfl = 0;
+		}
+	}
+
+	if (intr_sr & XPS2_IPIXR_TX_ACK)
+		drvdata->dfl = 0;
+
+	return IRQ_HANDLED;
+}
+
+/*******************/
+/* serio callbacks */
+/*******************/
+
+/*
+ * sxps2_write() sends a byte out through the PS/2 interface.
+ */
+static int sxps2_write(struct serio *pserio, unsigned char c)
+{
+	struct xps2data *drvdata = pserio->port_data;
+	unsigned long flags;
+	u32 sr;
+	int status = -1;
+
+	spin_lock_irqsave(&drvdata->lock, flags);
+
+	/* If the PS/2 transmitter is empty send a byte of data */
+	sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET);
+	if (!(sr & XPS2_STATUS_TX_FULL)) {
+		out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c);
+		status = 0;
+	}
+
+	spin_unlock_irqrestore(&drvdata->lock, flags);
+
+	return status;
+}
+
+/*
+ * sxps2_open() is called when a port is open by the higher layer.
+ */
+static int sxps2_open(struct serio *pserio)
+{
+	struct xps2data *drvdata = pserio->port_data;
+	int retval;
+
+	retval = request_irq(drvdata->irq, &xps2_interrupt, 0,
+				DRIVER_NAME, drvdata);
+	if (retval) {
+		printk(KERN_ERR
+			"%s: Couldn't allocate interrupt %d\n",
+			drvdata->serio.name, drvdata->irq);
+		return retval;
+	}
+
+	/* start reception by enabling the interrupts */
+	out_be32(drvdata->base_address + XPS2_GIER_OFFSET, XPS2_GIER_GIE_MASK);
+	out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, XPS2_IPIXR_RX_ALL);
+	(void)xps2_recv(drvdata, &drvdata->rxb);
+
+	return 0;		/* success */
+}
+
+/*
+ * sxps2_close() frees the interrupt.
+ */
+static void sxps2_close(struct serio *pserio)
+{
+	struct xps2data *drvdata = pserio->port_data;
+
+	/* Disable the PS2 interrupts */
+	out_be32(drvdata->base_address + XPS2_GIER_OFFSET, 0x00);
+	out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0x00);
+	free_irq(drvdata->irq, drvdata);
+}
+
+/*********************/
+/* Device setup code */
+/*********************/
+
+static int xps2_setup(struct device *dev, struct resource *regs_res,
+		      struct resource *irq_res)
+{
+	struct xps2data *drvdata;
+	struct serio *serio;
+	unsigned long remap_size;
+	int retval;
+
+	if (!dev)
+		return -EINVAL;
+
+	if (!regs_res || !irq_res) {
+		dev_err(dev, "IO resource(s) not found\n");
+		return -EINVAL;
+	}
+
+	drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL);
+	if (!drvdata) {
+		dev_err(dev, "Couldn't allocate device private record\n");
+		return -ENOMEM;
+	}
+
+	dev_set_drvdata(dev, drvdata);
+
+	spin_lock_init(&drvdata->lock);
+	drvdata->irq = irq_res->start;
+
+	remap_size = regs_res->end - regs_res->start + 1;
+	if (!request_mem_region(regs_res->start, remap_size, DRIVER_NAME)) {
+		dev_err(dev, "Couldn't lock memory region at 0x%08X\n",
+			(unsigned int)regs_res->start);
+		retval = -EBUSY;
+		goto failed1;
+	}
+
+	/* Fill in configuration data and add them to the list */
+	drvdata->phys_addr = regs_res->start;
+	drvdata->remap_size = remap_size;
+	drvdata->base_address = ioremap(regs_res->start, remap_size);
+	if (drvdata->base_address == NULL) {
+		dev_err(dev, "Couldn't ioremap memory at 0x%08X\n",
+			(unsigned int)regs_res->start);
+		retval = -EFAULT;
+		goto failed2;
+	}
+
+	/* Disable all the interrupts, just in case */
+	out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0);
+
+	/* Reset the PS2 device and abort any current transaction, to make sure
+	 * we have the PS2 in a good state */
+	out_be32(drvdata->base_address + XPS2_SRST_OFFSET, XPS2_SRST_RESET);
+
+	dev_info(dev, "Xilinx PS2 at 0x%08X mapped to 0x%08X, irq=%d\n",
+		drvdata->phys_addr, (u32)drvdata->base_address, drvdata->irq);
+
+	serio = &drvdata->serio;
+	serio->id.type = SERIO_8042;
+	serio->write = sxps2_write;
+	serio->open = sxps2_open;
+	serio->close = sxps2_close;
+	serio->port_data = drvdata;
+	serio->dev.parent = dev;
+	snprintf(serio->name, sizeof(serio->name),
+		 "Xilinx XPS PS/2 at %08X", drvdata->phys_addr);
+	snprintf(serio->phys, sizeof(serio->phys),
+		 "xilinxps2/serio at %08X", drvdata->phys_addr);
+	serio_register_port(serio);
+
+	return 0;		/* success */
+
+failed2:
+	release_mem_region(regs_res->start, remap_size);
+failed1:
+	kfree(drvdata);
+	dev_set_drvdata(dev, NULL);
+
+	return retval;
+}
+
+/***************************/
+/* OF Platform Bus Support */
+/***************************/
+
+static int __devinit xps2_of_probe(struct of_device *ofdev, const struct
+				   of_device_id * match)
+{
+	struct resource r_irq; /* Interrupt resources */
+	struct resource r_mem; /* IO mem resources */
+	int rc = 0;
+
+	printk(KERN_INFO "Device Tree Probing \'%s\'\n",
+			ofdev->node->name);
+
+	/* Get iospace for the device */
+	rc = of_address_to_resource(ofdev->node, 0, &r_mem);
+	if (rc) {
+		dev_err(&ofdev->dev, "invalid address\n");
+		return rc;
+	}
+
+	/* Get IRQ for the device */
+	rc = of_irq_to_resource(ofdev->node, 0, &r_irq);
+	if (rc == NO_IRQ) {
+		dev_err(&ofdev->dev, "no IRQ found\n");
+		return rc;
+	}
+
+	return xps2_setup(&ofdev->dev, &r_mem, &r_irq);
+}
+
+static int __devexit xps2_of_remove(struct of_device *of_dev)
+{
+	struct device *dev = &of_dev->dev;
+	struct xps2data *drvdata;
+
+	if (!dev)
+		return -EINVAL;
+
+	drvdata = dev_get_drvdata(dev);
+
+	serio_unregister_port(&drvdata->serio);
+	iounmap(drvdata->base_address);
+	release_mem_region(drvdata->phys_addr, drvdata->remap_size);
+	kfree(drvdata);
+
+	dev_set_drvdata(dev, NULL);
+
+	return 0;		/* success */
+}
+
+/* Match table for of_platform binding */
+static struct of_device_id xps2_of_match[] __devinitdata = {
+	{ .compatible = "xlnx,xps-ps2-1.00.a", },
+	{ /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, xps2_of_match);
+
+static struct of_platform_driver xps2_of_driver = {
+	.name		= DRIVER_NAME,
+	.match_table	= xps2_of_match,
+	.probe		= xps2_of_probe,
+	.remove		= __devexit_p(xps2_of_remove),
+};
+
+static int __init xps2_init(void)
+{
+	return of_register_platform_driver(&xps2_of_driver);
+}
+
+static void __exit xps2_cleanup(void)
+{
+	of_unregister_platform_driver(&xps2_of_driver);
+}
+
+module_init(xps2_init);
+module_exit(xps2_cleanup);
+
+MODULE_AUTHOR("Xilinx, Inc.");
+MODULE_DESCRIPTION("Xilinx XPS PS/2 driver");
+MODULE_LICENSE("GPL");
+