--- /dev/null
+/*
+ * Copyright (C) 2013 Aeroflex Gaisler
+ *
+ * This driver supports the APBPS2 PS/2 core available in the GRLIB
+ * VHDL IP core library.
+ *
+ * Full documentation of the APBPS2 core can be found here:
+ * http://www.gaisler.com/products/grlib/grip.pdf
+ *
+ * See "Documentation/devicetree/bindings/input/ps2keyb-mouse-apbps2.txt" for
+ * information on open firmware properties.
+ *
+ * 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.
+ *
+ * Contributors: Daniel Hellstrom <daniel@gaisler.com>
+ */
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/module.h>
+#include <linux/serio.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+
+struct apbps2_regs {
+ u32 __iomem data; /* 0x00 */
+ u32 __iomem status; /* 0x04 */
+ u32 __iomem ctrl; /* 0x08 */
+ u32 __iomem reload; /* 0x0c */
+};
+
+#define APBPS2_STATUS_DR (1<<0)
+#define APBPS2_STATUS_PE (1<<1)
+#define APBPS2_STATUS_FE (1<<2)
+#define APBPS2_STATUS_KI (1<<3)
+#define APBPS2_STATUS_RF (1<<4)
+#define APBPS2_STATUS_TF (1<<5)
+#define APBPS2_STATUS_TCNT (0x1f<<22)
+#define APBPS2_STATUS_RCNT (0x1f<<27)
+
+#define APBPS2_CTRL_RE (1<<0)
+#define APBPS2_CTRL_TE (1<<1)
+#define APBPS2_CTRL_RI (1<<2)
+#define APBPS2_CTRL_TI (1<<3)
+
+struct apbps2_priv {
+ struct serio *io;
+ struct apbps2_regs *regs;
+};
+
+static int apbps2_idx;
+
+static irqreturn_t apbps2_isr(int irq, void *dev_id)
+{
+ struct apbps2_priv *priv = dev_id;
+ unsigned long status, data, rxflags;
+ irqreturn_t ret = IRQ_NONE;
+
+ while ((status = ioread32be(&priv->regs->status)) & APBPS2_STATUS_DR) {
+ data = ioread32be(&priv->regs->data);
+ rxflags = (status & APBPS2_STATUS_PE) ? SERIO_PARITY : 0;
+ rxflags |= (status & APBPS2_STATUS_FE) ? SERIO_FRAME : 0;
+
+ /* clear error bits? */
+ if (rxflags)
+ iowrite32be(0, &priv->regs->status);
+
+ serio_interrupt(priv->io, data, rxflags);
+
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+static int apbps2_write(struct serio *io, unsigned char val)
+{
+ struct apbps2_priv *priv = io->port_data;
+ unsigned int tleft = 10000; /* timeout in 100ms */
+
+ /* delay until PS/2 controller has room for more chars */
+ while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) && tleft--)
+ udelay(10);
+
+ if ((ioread32be(&priv->regs->status) & APBPS2_STATUS_TF) == 0) {
+ iowrite32be(val, &priv->regs->data);
+
+ iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI | APBPS2_CTRL_TE,
+ &priv->regs->ctrl);
+ return 0;
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int apbps2_open(struct serio *io)
+{
+ struct apbps2_priv *priv = io->port_data;
+ int limit;
+ unsigned long tmp;
+
+ /* clear error flags */
+ iowrite32be(0, &priv->regs->status);
+
+ /* Clear old data if available (unlikely) */
+ limit = 1024;
+ while ((ioread32be(&priv->regs->status) & APBPS2_STATUS_DR) && --limit)
+ tmp = ioread32be(&priv->regs->data);
+
+ /* Enable reciever and it's interrupt */
+ iowrite32be(APBPS2_CTRL_RE | APBPS2_CTRL_RI, &priv->regs->ctrl);
+
+ return 0;
+}
+
+static void apbps2_close(struct serio *io)
+{
+ struct apbps2_priv *priv = io->port_data;
+
+ /* stop interrupts at PS/2 HW level */
+ iowrite32be(0, &priv->regs->ctrl);
+}
+
+/* Initialize one APBPS2 PS/2 core */
+static int apbps2_of_probe(struct platform_device *ofdev)
+{
+ struct apbps2_priv *priv;
+ int irq, err;
+ u32 freq_hz;
+ struct resource *res;
+
+ priv = devm_kzalloc(&ofdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv) {
+ dev_err(&ofdev->dev, "memory allocation failed\n");
+ return -ENOMEM;
+ }
+
+ /* Find Device Address */
+ res = platform_get_resource(ofdev, IORESOURCE_MEM, 0);
+ priv->regs = devm_request_and_ioremap(&ofdev->dev, res);
+ if (!priv->regs) {
+ dev_err(&ofdev->dev, "io-regs mapping failed\n");
+ return -EBUSY;
+ }
+
+ /* Reset hardware, disable interrupt */
+ iowrite32be(0, &priv->regs->ctrl);
+
+ /* IRQ */
+ irq = irq_of_parse_and_map(ofdev->dev.of_node, 0);
+ err = devm_request_irq(&ofdev->dev, irq, apbps2_isr,
+ IRQF_SHARED, "apbps2", priv);
+ if (err) {
+ dev_err(&ofdev->dev, "request IRQ%d failed\n", irq);
+ return err;
+ }
+
+ /* Get core frequency */
+ if (of_property_read_u32(ofdev->dev.of_node, "freq", &freq_hz)) {
+ dev_err(&ofdev->dev, "unable to get core frequency\n");
+ return -EINVAL;
+ }
+
+ /* Set reload register to core freq in kHz/10 */
+ iowrite32be(freq_hz / 10000, &priv->regs->reload);
+
+ priv->io = kzalloc(sizeof(struct serio), GFP_KERNEL);
+ if (!priv->io)
+ return -ENOMEM;
+
+ priv->io->id.type = SERIO_8042;
+ priv->io->open = apbps2_open;
+ priv->io->close = apbps2_close;
+ priv->io->write = apbps2_write;
+ priv->io->port_data = priv;
+ strlcpy(priv->io->name, "APBPS2 PS/2", sizeof(priv->io->name));
+ snprintf(priv->io->phys, sizeof(priv->io->phys),
+ "apbps2_%d", apbps2_idx++);
+
+ dev_info(&ofdev->dev, "irq = %d, base = 0x%p\n", irq, priv->regs);
+
+ serio_register_port(priv->io);
+
+ platform_set_drvdata(ofdev, priv);
+
+ return 0;
+}
+
+static int apbps2_of_remove(struct platform_device *of_dev)
+{
+ struct apbps2_priv *priv = platform_get_drvdata(of_dev);
+
+ serio_unregister_port(priv->io);
+
+ return 0;
+}
+
+static struct of_device_id apbps2_of_match[] = {
+ { .name = "GAISLER_APBPS2", },
+ { .name = "01_060", },
+ {}
+};
+
+MODULE_DEVICE_TABLE(of, apbps2_of_match);
+
+static struct platform_driver apbps2_of_driver = {
+ .driver = {
+ .name = "grlib-apbps2",
+ .owner = THIS_MODULE,
+ .of_match_table = apbps2_of_match,
+ },
+ .probe = apbps2_of_probe,
+ .remove = apbps2_of_remove,
+};
+
+module_platform_driver(apbps2_of_driver);
+
+MODULE_AUTHOR("Aeroflex Gaisler AB.");
+MODULE_DESCRIPTION("GRLIB APBPS2 PS/2 serial I/O");
+MODULE_LICENSE("GPL");
projects / firefly-linux-kernel-4.4.55.git / commitdiff