Re: [PATCH] powerpc: Xilinx: PS2: Added new XPS PS2 driver

---
 drivers/input/serio/Kconfig      |    5 +
 drivers/input/serio/Makefile     |    1 +
 drivers/input/serio/xilinx_ps2.c |  464 ++++++++++++++++++++++++++++++++++++++
 drivers/input/serio/xilinx_ps2.h |   97 ++++++++
 4 files changed, 567 insertions(+), 0 deletions(-)
 create mode 100644 drivers/input/serio/xilinx_ps2.c
 create mode 100644 drivers/input/serio/xilinx_ps2.h

diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index ec4b661..0e62b39 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig

@@ -190,4 +190,9 @@ 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"
+	help
+	  This driver supports XPS PS/2 IP from Xilinx EDK.
+

 endif

diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
index 38b8868..9b6c813 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 0000000..670d47f
--- /dev/null
+++ b/drivers/input/serio/xilinx_ps2.c

@@ -0,0 +1,464 @@
+/*
+ * xilinx_ps2.c

+ *
+ * Xilinx PS/2 driver to interface PS/2 component to Linux
+ *
+ * Author: MontaVista Software, Inc.
+ *	   source@mvista.com

+ *
+ * (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 <asm/io.h>
+
+#ifdef CONFIG_OF		/* For open firmware */
+ #include <linux/of_device.h>
+ #include <linux/of_platform.h>
+#endif /* CONFIG_OF */

+#define DRIVER_DESCRIPTION	"Xilinx XPS PS/2 driver"
+#define XPS2_NAME_DESC		"Xilinx XPS PS/2 Port #%d"
+#define XPS2_PHYS_DESC		"xilinxps2/serio%d"

+
+
+static DECLARE_MUTEX(cfg_sem);

+
+/*********************/
+/* Interrupt handler */
+/*********************/
+static irqreturn_t xps2_interrupt(int irq, void *dev_id)
+{
+	struct xps2data *drvdata = (struct xps2data *)dev_id;
+	u32 intr_sr;
+	u32 ier;
+	u8 c;
+	u8 retval;
+
+	/* 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_ERR "%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) {
+		retval = xps2_recv(drvdata, &drvdata->rxb);
+
+		/* Error, if 1 byte is not received */
+		if (retval != 1) {
+			printk(KERN_ERR
+				"%s: wrong rcvd byte count (%d)\n",
+				drvdata->serio.name, retval);
+		}
+		c = drvdata->rxb;
+		serio_interrupt(&drvdata->serio, c, drvdata->dfl);
+		drvdata->dfl = 0;
+	}
+
+	if (intr_sr & XPS2_IPIXR_TX_ACK) {
+
+		/* Disable the TX interrupts after the transmission is
+		 * complete */
+		ier = in_be32(drvdata->base_address + XPS2_IPIER_OFFSET);
+		ier &= (~(XPS2_IPIXR_TX_ACK & XPS2_IPIXR_ALL ));
+		out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, ier);
+		drvdata->dfl = 0;
+	}
+
+	return IRQ_HANDLED;
+}
+
+/*******************/
+/* serio callbacks */
+/*******************/
+
+/*
+ * sxps2_write() sends a byte out through the PS/2 interface.
+ *
+ * The sole purpose of drvdata->tx_end is to prevent the driver
+ * from locking up in the do {} while; loop when nothing is connected
+ * to the given PS/2 port. That's why we do not try to recover
+ * from the transmission failure.
+ * drvdata->tx_end needs not to be initialized to some "far in the
+ * future" value, as the very first attempt to xps2_send() a byte
+ * is always successful, and drvdata->tx_end will be set to a proper
+ * value at that moment - before the 1st use in the comparison.
+ */

+static int sxps2_write(struct serio *pserio, unsigned char c)
+{
+	struct xps2data *drvdata = pserio->port_data;
+	unsigned long flags;
+	int retval;
+
+	do {
+		spin_lock_irqsave(&drvdata->lock, flags);
+		retval = xps2_send(drvdata, &c);
+		spin_unlock_irqrestore(&drvdata->lock, flags);
+
+		if (retval == 1) {
+			drvdata->tx_end = jiffies + HZ;
+			return 0;	/* success */
+		}
+	} while (!time_after(jiffies, drvdata->tx_end));
+
+	return 1;			/* transmission is frozen */
+}
+
+/*
+ * 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);
+}
+
+/*************************/
+/* XPS PS/2 driver calls */
+/*************************/
+
+/*
+ * xps2_initialize() initializes the Xilinx PS/2 device.
+ */
+static int xps2_initialize(struct xps2data *drvdata)
+{
+	/* 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);
+
+	return 0;
+}
+
+/*
+ * xps2_send() sends the specified byte of data to the PS/2 port in interrupt
+ * mode.
+ */
+static u8 xps2_send(struct xps2data *drvdata, u8 *byte)
+{
+	u32 sr;
+	u32 ier;
+	u8 retval = 0;
+
+	/* Enter a critical region by disabling the PS/2 transmit interrupts to
+	 * allow this call to stop a previous operation that may be interrupt
+	 * driven. Only stop the transmit interrupt since this critical region
+	 * is not really exited in the normal manner */
+	ier = in_be32(drvdata->base_address + XPS2_IPIER_OFFSET);
+	ier &= (~(XPS2_IPIXR_TX_ALL & XPS2_IPIXR_ALL ));
+	out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, ier);
+
+	/* 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) == 0) {
+		out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, *byte);
+		retval = 1;
+	}
+
+	/* Enable the TX interrupts to track the status of the transmission */
+	ier = in_be32(drvdata->base_address + XPS2_IPIER_OFFSET);
+	ier |= ((XPS2_IPIXR_TX_ALL | XPS2_IPIXR_WDT_TOUT ));
+	out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, ier);
+
+	return retval;		/* no. of bytes sent */
+}
+
+/*
+ * xps2_recv() will attempt to receive a byte of data from the PS/2 port.
+ */
+static u8 xps2_recv(struct xps2data *drvdata, u8 *byte)
+{
+	u32 sr;
+	u8 retval = 0;
+
+	/* 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);
+		retval = 1;
+	}
+
+	return retval;		/* no. of bytes received */
+}

+
+/******************************/
+/* The platform device driver */
+/******************************/

+static struct device_driver xps2_driver = {
+	.name = DRIVER_NAME,
+	.bus = &platform_bus_type,
+	.probe = xps2_probe,
+	.remove = xps2_remove
+};

new file mode 100644
index 0000000..4db73ca

--- /dev/null
+++ b/drivers/input/serio/xilinx_ps2.h

@@ -0,0 +1,97 @@
+/*****************************************************************************
+ *
+ *     Author: 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.
+ *
+ *     XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
+ *     AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
+ *     SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
+ *     OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
+ *     APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
+ *     THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
+ *     AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
+ *     FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
+ *     WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
+ *     IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
+ *     REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
+ *     INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ *     FOR A PARTICULAR PURPOSE.

+
+static u8 xps2_send(struct xps2data *drvdata, u8 *buffer_ptr);
+static u8 xps2_recv(struct xps2data *drvdata, u8 *buffer_ptr);
+static int xps2_initialize(struct xps2data *drvdata);
+static int xps2_setup(struct device *dev, int id, struct resource *regs_res,
+		      struct resource *irq_res);