diff options
Diffstat (limited to 'drivers/input/serio/altera_ps2.c')
| -rw-r--r-- | drivers/input/serio/altera_ps2.c | 164 |
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); |