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path: root/drivers/input/serio/altera_ps2.c
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Diffstat (limited to 'drivers/input/serio/altera_ps2.c')
-rw-r--r--drivers/input/serio/altera_ps2.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/input/serio/altera_ps2.c b/drivers/input/serio/altera_ps2.c
new file mode 100644
index 000000000..3a92304f6
--- /dev/null
+++ b/drivers/input/serio/altera_ps2.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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
+ */
+
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/serio.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#define DRV_NAME "altera_ps2"
+
+struct ps2if {
+ struct serio *io;
+ void __iomem *base;
+};
+
+/*
+ * 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;
+ irqreturn_t 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 + 4); /* disable rx irq */
+}
+
+/*
+ * Add one device to this driver.
+ */
+static int altera_ps2_probe(struct platform_device *pdev)
+{
+ struct ps2if *ps2if;
+ struct resource *res;
+ struct serio *serio;
+ int error, irq;
+
+ ps2if = devm_kzalloc(&pdev->dev, sizeof(struct ps2if), GFP_KERNEL);
+ if (!ps2if)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ ps2if->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(ps2if->base))
+ return PTR_ERR(ps2if->base);
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return -ENXIO;
+
+ error = devm_request_irq(&pdev->dev, irq, altera_ps2_rxint, 0,
+ pdev->name, ps2if);
+ if (error) {
+ dev_err(&pdev->dev, "could not request IRQ %d\n", irq);
+ return error;
+ }
+
+ serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+ if (!serio)
+ return -ENOMEM;
+
+ serio->id.type = SERIO_8042;
+ serio->write = altera_ps2_write;
+ serio->open = altera_ps2_open;
+ serio->close = altera_ps2_close;
+ strscpy(serio->name, dev_name(&pdev->dev), sizeof(serio->name));
+ strscpy(serio->phys, dev_name(&pdev->dev), sizeof(serio->phys));
+ serio->port_data = ps2if;
+ serio->dev.parent = &pdev->dev;
+ ps2if->io = serio;
+
+ dev_info(&pdev->dev, "base %p, irq %d\n", ps2if->base, irq);
+
+ serio_register_port(ps2if->io);
+ platform_set_drvdata(pdev, ps2if);
+
+ return 0;
+}
+
+/*
+ * Remove one device from this driver.
+ */
+static int altera_ps2_remove(struct platform_device *pdev)
+{
+ struct ps2if *ps2if = platform_get_drvdata(pdev);
+
+ serio_unregister_port(ps2if->io);
+
+ return 0;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id altera_ps2_match[] = {
+ { .compatible = "ALTR,ps2-1.0", },
+ { .compatible = "altr,ps2-1.0", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, altera_ps2_match);
+#endif /* CONFIG_OF */
+
+/*
+ * Our device driver structure
+ */
+static struct platform_driver altera_ps2_driver = {
+ .probe = altera_ps2_probe,
+ .remove = altera_ps2_remove,
+ .driver = {
+ .name = DRV_NAME,
+ .of_match_table = of_match_ptr(altera_ps2_match),
+ },
+};
+module_platform_driver(altera_ps2_driver);
+
+MODULE_DESCRIPTION("Altera University Program PS2 controller driver");
+MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);