--- /dev/null
+/*
+ * 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/slab.h>
+#include <linux/list.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/of_irq.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;
+ spinlock_t lock;
+ void __iomem *base_address; /* virt. address of control registers */
+ unsigned int flags;
+ struct serio *serio; /* serio */
+ struct device *dev;
+};
+
+/************************************/
+/* XPS PS/2 data transmission calls */
+/************************************/
+
+/**
+ * xps2_recv() - attempts to receive a byte from the PS/2 port.
+ * @drvdata: pointer to ps2 device private data structure
+ * @byte: address where the read data will be copied
+ *
+ * If there is any data available in the PS/2 receiver, this functions reads
+ * the data, otherwise it returns error.
+ */
+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)
+ dev_warn(drvdata->dev, "receive overrun error\n");
+
+ if (intr_sr & XPS2_IPIXR_RX_ERR)
+ drvdata->flags |= SERIO_PARITY;
+
+ if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT))
+ drvdata->flags |= SERIO_TIMEOUT;
+
+ if (intr_sr & XPS2_IPIXR_RX_FULL) {
+ status = xps2_recv(drvdata, &c);
+
+ /* Error, if a byte is not received */
+ if (status) {
+ dev_err(drvdata->dev,
+ "wrong rcvd byte count (%d)\n", status);
+ } else {
+ serio_interrupt(drvdata->serio, c, drvdata->flags);
+ drvdata->flags = 0;
+ }
+ }
+
+ return IRQ_HANDLED;
+}
+
+/*******************/
+/* serio callbacks */
+/*******************/
+
+/**
+ * sxps2_write() - sends a byte out through the PS/2 port.
+ * @pserio: pointer to the serio structure of the PS/2 port
+ * @c: data that needs to be written to the PS/2 port
+ *
+ * This function checks if the PS/2 transmitter is empty and sends a byte.
+ * Otherwise it returns error. Transmission fails only when nothing is connected
+ * to the PS/2 port. Thats why, we do not try to resend the data in case of a
+ * failure.
+ */
+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() - called when a port is opened by the higher layer.
+ * @pserio: pointer to the serio structure of the PS/2 device
+ *
+ * This function requests irq and enables interrupts for the PS/2 device.
+ */
+static int sxps2_open(struct serio *pserio)
+{
+ struct xps2data *drvdata = pserio->port_data;
+ int error;
+ u8 c;
+
+ error = request_irq(drvdata->irq, &xps2_interrupt, 0,
+ DRIVER_NAME, drvdata);
+ if (error) {
+ dev_err(drvdata->dev,
+ "Couldn't allocate interrupt %d\n", drvdata->irq);
+ return error;
+ }
+
+ /* 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, &c);
+
+ return 0; /* success */
+}
+
+/**
+ * sxps2_close() - frees the interrupt.
+ * @pserio: pointer to the serio structure of the PS/2 device
+ *
+ * This function frees the irq and disables interrupts for the PS/2 device.
+ */
+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);
+}
+
+/**
+ * xps2_of_probe - probe method for the PS/2 device.
+ * @of_dev: pointer to OF device structure
+ * @match: pointer to the structure used for matching a device
+ *
+ * This function probes the PS/2 device in the device tree.
+ * It initializes the driver data structure and the hardware.
+ * It returns 0, if the driver is bound to the PS/2 device, or a negative
+ * value if there is an error.
+ */
+static int xps2_of_probe(struct platform_device *ofdev)
+{
+ struct resource r_mem; /* IO mem resources */
+ struct xps2data *drvdata;
+ struct serio *serio;
+ struct device *dev = &ofdev->dev;
+ resource_size_t remap_size, phys_addr;
+ unsigned int irq;
+ int error;
+
+ dev_info(dev, "Device Tree Probing \'%s\'\n",
+ ofdev->dev.of_node->name);
+
+ /* Get iospace for the device */
+ error = of_address_to_resource(ofdev->dev.of_node, 0, &r_mem);
+ if (error) {
+ dev_err(dev, "invalid address\n");
+ return error;
+ }
+
+ /* Get IRQ for the device */
+ irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
+ if (!irq) {
+ dev_err(dev, "no IRQ found\n");
+ return -ENODEV;
+ }
+
+ drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL);
+ serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+ if (!drvdata || !serio) {
+ error = -ENOMEM;
+ goto failed1;
+ }
+
+ spin_lock_init(&drvdata->lock);
+ drvdata->irq = irq;
+ drvdata->serio = serio;
+ drvdata->dev = dev;
+
+ phys_addr = r_mem.start;
+ remap_size = resource_size(&r_mem);
+ if (!request_mem_region(phys_addr, remap_size, DRIVER_NAME)) {
+ dev_err(dev, "Couldn't lock memory region at 0x%08llX\n",
+ (unsigned long long)phys_addr);
+ error = -EBUSY;
+ goto failed1;
+ }
+
+ /* Fill in configuration data and add them to the list */
+ drvdata->base_address = ioremap(phys_addr, remap_size);
+ if (drvdata->base_address == NULL) {
+ dev_err(dev, "Couldn't ioremap memory at 0x%08llX\n",
+ (unsigned long long)phys_addr);
+ error = -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%08llX mapped to 0x%p, irq=%d\n",
+ (unsigned long long)phys_addr, drvdata->base_address,
+ drvdata->irq);
+
+ 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 %08llX", (unsigned long long)phys_addr);
+ snprintf(serio->phys, sizeof(serio->phys),
+ "xilinxps2/serio at %08llX", (unsigned long long)phys_addr);
+
+ serio_register_port(serio);
+
+ platform_set_drvdata(ofdev, drvdata);
+ return 0; /* success */
+
+failed2:
+ release_mem_region(phys_addr, remap_size);
+failed1:
+ kfree(serio);
+ kfree(drvdata);
+
+ return error;
+}
+
+/**
+ * xps2_of_remove - unbinds the driver from the PS/2 device.
+ * @of_dev: pointer to OF device structure
+ *
+ * This function is called if a device is physically removed from the system or
+ * if the driver module is being unloaded. It frees any resources allocated to
+ * the device.
+ */
+static int xps2_of_remove(struct platform_device *of_dev)
+{
+ struct xps2data *drvdata = platform_get_drvdata(of_dev);
+ struct resource r_mem; /* IO mem resources */
+
+ serio_unregister_port(drvdata->serio);
+ iounmap(drvdata->base_address);
+
+ /* Get iospace of the device */
+ if (of_address_to_resource(of_dev->dev.of_node, 0, &r_mem))
+ dev_err(drvdata->dev, "invalid address\n");
+ else
+ release_mem_region(r_mem.start, resource_size(&r_mem));
+
+ kfree(drvdata);
+
+ return 0;
+}
+
+/* Match table for of_platform binding */
+static const struct of_device_id xps2_of_match[] = {
+ { .compatible = "xlnx,xps-ps2-1.00.a", },
+ { /* end of list */ },
+};
+MODULE_DEVICE_TABLE(of, xps2_of_match);
+
+static struct platform_driver xps2_of_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = xps2_of_match,
+ },
+ .probe = xps2_of_probe,
+ .remove = xps2_of_remove,
+};
+module_platform_driver(xps2_of_driver);
+
+MODULE_AUTHOR("Xilinx, Inc.");
+MODULE_DESCRIPTION("Xilinx XPS PS/2 driver");
+MODULE_LICENSE("GPL");
+
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