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>

3 files changed, 391 insertions, 0 deletions

diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index ec4b6610f730..27d70d326ff3 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -190,4 +190,14 @@ config SERIO_RAW
           To compile this driver as a module, choose M here: the
           module will be called serio_raw.
 
+config SERIO_XILINX_XPS_PS2
+        tristate "Xilinx XPS PS/2 Controller Support"
+        depends on PPC
+        help
+          This driver supports XPS PS/2 IP from the Xilinx EDK on
+          PowerPC platform.
+
+          To compile this driver as a module, choose M here: the
+          module will be called xilinx_ps2.
+
 endif
diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
index 38b886887cbc..9b6c8135955f 100644
--- a/drivers/input/serio/Makefile
+++ b/drivers/input/serio/Makefile
@@ -21,3 +21,4 @@ obj-$(CONFIG_SERIO_PCIPS2)	+= pcips2.o
 obj-$(CONFIG_SERIO_MACEPS2)     += maceps2.o
 obj-$(CONFIG_SERIO_LIBPS2)      += libps2.o
 obj-$(CONFIG_SERIO_RAW)         += serio_raw.o
+obj-$(CONFIG_SERIO_XILINX_XPS_PS2)      += xilinx_ps2.o
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");
+