Input: add driver for Altera PS/2 controller

This patch adds a new SERIO driver to support the Altera University
Program PS/2 controller.

[dtor@mail.ru: assorted cleanups]
Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

3 files changed, 209 insertions, 0 deletions

diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index aa533ceffe3..7e319d65ec5 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -201,4 +201,12 @@ config SERIO_XILINX_XPS_PS2
           To compile this driver as a module, choose M here: the
           module will be called xilinx_ps2.
 
+config SERIO_ALTERA_PS2
+        tristate "Altera UP PS/2 controller"
+        help
+          Say Y here if you have Altera University Program PS/2 ports.
+
+          To compile this driver as a module, choose M here: the
+          module will be called altera_ps2.
+
 endif
diff --git a/drivers/input/serio/Makefile b/drivers/input/serio/Makefile
index 9b6c8135955..bf945f789d0 100644
--- a/drivers/input/serio/Makefile
+++ b/drivers/input/serio/Makefile
@@ -22,3 +22,4 @@ 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
+obj-$(CONFIG_SERIO_ALTERA_PS2)  += altera_ps2.o
diff --git a/drivers/input/serio/altera_ps2.c b/drivers/input/serio/altera_ps2.c
new file mode 100644
index 00000000000..f479ea50919
--- /dev/null
+++ b/drivers/input/serio/altera_ps2.c
@@ -0,0 +1,200 @@
+/*
+ * Altera University Program PS2 controller driver
+ *
+ * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
+ *
+ * Based on sa1111ps2.c, which is:
+ * Copyright (C) 2002 Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+
+#define DRV_NAME "altera_ps2"
+
+struct ps2if {
+        struct serio *io;
+        struct resource *iomem_res;
+        void __iomem *base;
+        unsigned irq;
+};
+
+/*
+ * Read all bytes waiting in the PS2 port.  There should be
+ * at the most one, but we loop for safety.
+ */
+static irqreturn_t altera_ps2_rxint(int irq, void *dev_id)
+{
+        struct ps2if *ps2if = dev_id;
+        unsigned int status;
+        int handled = IRQ_NONE;
+
+        while ((status = readl(ps2if->base)) & 0xffff0000) {
+                serio_interrupt(ps2if->io, status & 0xff, 0);
+                handled = IRQ_HANDLED;
+        }
+
+        return handled;
+}
+
+/*
+ * Write a byte to the PS2 port.
+ */
+static int altera_ps2_write(struct serio *io, unsigned char val)
+{
+        struct ps2if *ps2if = io->port_data;
+
+        writel(val, ps2if->base);
+        return 0;
+}
+
+static int altera_ps2_open(struct serio *io)
+{
+        struct ps2if *ps2if = io->port_data;
+
+        /* clear fifo */
+        while (readl(ps2if->base) & 0xffff0000)
+                /* empty */;
+
+        writel(1, ps2if->base + 4); /* enable rx irq */
+        return 0;
+}
+
+static void altera_ps2_close(struct serio *io)
+{
+        struct ps2if *ps2if = io->port_data;
+
+        writel(0, ps2if->base); /* disable rx irq */
+}
+
+/*
+ * Add one device to this driver.
+ */
+static int altera_ps2_probe(struct platform_device *pdev)
+{
+        struct ps2if *ps2if;
+        struct serio *serio;
+        int error;
+
+        ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL);
+        serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+        if (!ps2if || !serio) {
+                error = -ENOMEM;
+                goto err_free_mem;
+        }
+
+        serio->id.type          = SERIO_8042;
+        serio->write            = altera_ps2_write;
+        serio->open             = altera_ps2_open;
+        serio->close            = altera_ps2_close;
+        strlcpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
+        strlcpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
+        serio->port_data        = ps2if;
+        serio->dev.parent       = &pdev->dev;
+        ps2if->io               = serio;
+
+        ps2if->iomem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (ps2if->iomem_res == NULL) {
+                error = -ENOENT;
+                goto err_free_mem;
+        }
+
+        ps2if->irq  = platform_get_irq(pdev, 0);
+        if (ps2if->irq < 0) {
+                error = -ENXIO;
+                goto err_free_mem;
+        }
+
+        if (!request_mem_region(ps2if->iomem_res->start,
+                                resource_size(ps2if->iomem_res), pdev->name)) {
+                error = -EBUSY;
+                goto err_free_mem;
+        }
+
+        ps2if->base = ioremap(ps2if->iomem_res->start,
+                              resource_size(ps2if->iomem_res));
+        if (!ps2if->base) {
+                error = -ENOMEM;
+                goto err_free_res;
+        }
+
+        error = request_irq(ps2if->irq, altera_ps2_rxint, 0, pdev->name, ps2if);
+        if (error) {
+                dev_err(&pdev->dev, "could not allocate IRQ %d: %d\n",
+                        ps2if->irq, error);
+                goto err_unmap;
+        }
+
+        dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, ps2if->irq);
+
+        serio_register_port(ps2if->io);
+        platform_set_drvdata(pdev, ps2if);
+
+        return 0;
+
+ err_unmap:
+        iounmap(ps2if->base);
+ err_free_res:
+        release_mem_region(ps2if->iomem_res->start,
+                           resource_size(ps2if->iomem_res));
+ err_free_mem:
+        kfree(ps2if);
+        kfree(serio);
+        return error;
+}
+
+/*
+ * Remove one device from this driver.
+ */
+static int altera_ps2_remove(struct platform_device *pdev)
+{
+        struct ps2if *ps2if = platform_get_drvdata(pdev);
+
+        platform_set_drvdata(pdev, NULL);
+        serio_unregister_port(ps2if->io);
+        free_irq(ps2if->irq, ps2if);
+        iounmap(ps2if->base);
+        release_mem_region(ps2if->iomem_res->start,
+                           resource_size(ps2if->iomem_res));
+        kfree(ps2if);
+
+        return 0;
+}
+
+/*
+ * Our device driver structure
+ */
+static struct platform_driver altera_ps2_driver = {
+        .probe          = altera_ps2_probe,
+        .remove         = altera_ps2_remove,
+        .driver = {
+                .name   = DRV_NAME,
+        },
+};
+
+static int __init altera_ps2_init(void)
+{
+        return platform_driver_register(&altera_ps2_driver);
+}
+
+static void __exit altera_ps2_exit(void)
+{
+        platform_driver_unregister(&altera_ps2_driver);
+}
+
+module_init(altera_ps2_init);
+module_exit(altera_ps2_exit);
+
+MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
+MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);