diff options
Diffstat (limited to 'drivers/input/serio/apbps2.c')
| -rw-r--r-- | drivers/input/serio/apbps2.c | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/drivers/input/serio/apbps2.c b/drivers/input/serio/apbps2.c new file mode 100644 index 000000000..594ac4e6f --- /dev/null +++ b/drivers/input/serio/apbps2.c @@ -0,0 +1,223 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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. + * + * 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 __iomem *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_ioremap_resource(&ofdev->dev, res); + if (IS_ERR(priv->regs)) + return PTR_ERR(priv->regs); + + /* 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 const 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", + .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"); |