diff options
Diffstat (limited to 'drivers/input/serio/sa1111ps2.c')
-rw-r--r-- | drivers/input/serio/sa1111ps2.c | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/drivers/input/serio/sa1111ps2.c b/drivers/input/serio/sa1111ps2.c new file mode 100644 index 0000000000..2724c3aa51 --- /dev/null +++ b/drivers/input/serio/sa1111ps2.c @@ -0,0 +1,386 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/drivers/input/serio/sa1111ps2.c + * + * Copyright (C) 2002 Russell King + */ +#include <linux/module.h> +#include <linux/init.h> +#include <linux/input.h> +#include <linux/serio.h> +#include <linux/errno.h> +#include <linux/interrupt.h> +#include <linux/ioport.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +#include <asm/io.h> + +#include <asm/hardware/sa1111.h> + +#define PS2CR 0x0000 +#define PS2STAT 0x0004 +#define PS2DATA 0x0008 +#define PS2CLKDIV 0x000c +#define PS2PRECNT 0x0010 + +#define PS2CR_ENA 0x08 +#define PS2CR_FKD 0x02 +#define PS2CR_FKC 0x01 + +#define PS2STAT_STP 0x0100 +#define PS2STAT_TXE 0x0080 +#define PS2STAT_TXB 0x0040 +#define PS2STAT_RXF 0x0020 +#define PS2STAT_RXB 0x0010 +#define PS2STAT_ENA 0x0008 +#define PS2STAT_RXP 0x0004 +#define PS2STAT_KBD 0x0002 +#define PS2STAT_KBC 0x0001 + +struct ps2if { + struct serio *io; + struct sa1111_dev *dev; + void __iomem *base; + int rx_irq; + int tx_irq; + unsigned int open; + spinlock_t lock; + unsigned int head; + unsigned int tail; + unsigned char buf[4]; +}; + +/* + * Read all bytes waiting in the PS2 port. There should be + * at the most one, but we loop for safety. If there was a + * framing error, we have to manually clear the status. + */ +static irqreturn_t ps2_rxint(int irq, void *dev_id) +{ + struct ps2if *ps2if = dev_id; + unsigned int scancode, flag, status; + + status = readl_relaxed(ps2if->base + PS2STAT); + while (status & PS2STAT_RXF) { + if (status & PS2STAT_STP) + writel_relaxed(PS2STAT_STP, ps2if->base + PS2STAT); + + flag = (status & PS2STAT_STP ? SERIO_FRAME : 0) | + (status & PS2STAT_RXP ? 0 : SERIO_PARITY); + + scancode = readl_relaxed(ps2if->base + PS2DATA) & 0xff; + + if (hweight8(scancode) & 1) + flag ^= SERIO_PARITY; + + serio_interrupt(ps2if->io, scancode, flag); + + status = readl_relaxed(ps2if->base + PS2STAT); + } + + return IRQ_HANDLED; +} + +/* + * Completion of ps2 write + */ +static irqreturn_t ps2_txint(int irq, void *dev_id) +{ + struct ps2if *ps2if = dev_id; + unsigned int status; + + spin_lock(&ps2if->lock); + status = readl_relaxed(ps2if->base + PS2STAT); + if (ps2if->head == ps2if->tail) { + disable_irq_nosync(irq); + /* done */ + } else if (status & PS2STAT_TXE) { + writel_relaxed(ps2if->buf[ps2if->tail], ps2if->base + PS2DATA); + ps2if->tail = (ps2if->tail + 1) & (sizeof(ps2if->buf) - 1); + } + spin_unlock(&ps2if->lock); + + return IRQ_HANDLED; +} + +/* + * Write a byte to the PS2 port. We have to wait for the + * port to indicate that the transmitter is empty. + */ +static int ps2_write(struct serio *io, unsigned char val) +{ + struct ps2if *ps2if = io->port_data; + unsigned long flags; + unsigned int head; + + spin_lock_irqsave(&ps2if->lock, flags); + + /* + * If the TX register is empty, we can go straight out. + */ + if (readl_relaxed(ps2if->base + PS2STAT) & PS2STAT_TXE) { + writel_relaxed(val, ps2if->base + PS2DATA); + } else { + if (ps2if->head == ps2if->tail) + enable_irq(ps2if->tx_irq); + head = (ps2if->head + 1) & (sizeof(ps2if->buf) - 1); + if (head != ps2if->tail) { + ps2if->buf[ps2if->head] = val; + ps2if->head = head; + } + } + + spin_unlock_irqrestore(&ps2if->lock, flags); + return 0; +} + +static int ps2_open(struct serio *io) +{ + struct ps2if *ps2if = io->port_data; + int ret; + + ret = sa1111_enable_device(ps2if->dev); + if (ret) + return ret; + + ret = request_irq(ps2if->rx_irq, ps2_rxint, 0, + SA1111_DRIVER_NAME(ps2if->dev), ps2if); + if (ret) { + printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n", + ps2if->rx_irq, ret); + sa1111_disable_device(ps2if->dev); + return ret; + } + + ret = request_irq(ps2if->tx_irq, ps2_txint, 0, + SA1111_DRIVER_NAME(ps2if->dev), ps2if); + if (ret) { + printk(KERN_ERR "sa1111ps2: could not allocate IRQ%d: %d\n", + ps2if->tx_irq, ret); + free_irq(ps2if->rx_irq, ps2if); + sa1111_disable_device(ps2if->dev); + return ret; + } + + ps2if->open = 1; + + enable_irq_wake(ps2if->rx_irq); + + writel_relaxed(PS2CR_ENA, ps2if->base + PS2CR); + return 0; +} + +static void ps2_close(struct serio *io) +{ + struct ps2if *ps2if = io->port_data; + + writel_relaxed(0, ps2if->base + PS2CR); + + disable_irq_wake(ps2if->rx_irq); + + ps2if->open = 0; + + free_irq(ps2if->tx_irq, ps2if); + free_irq(ps2if->rx_irq, ps2if); + + sa1111_disable_device(ps2if->dev); +} + +/* + * Clear the input buffer. + */ +static void ps2_clear_input(struct ps2if *ps2if) +{ + int maxread = 100; + + while (maxread--) { + if ((readl_relaxed(ps2if->base + PS2DATA) & 0xff) == 0xff) + break; + } +} + +static unsigned int ps2_test_one(struct ps2if *ps2if, + unsigned int mask) +{ + unsigned int val; + + writel_relaxed(PS2CR_ENA | mask, ps2if->base + PS2CR); + + udelay(10); + + val = readl_relaxed(ps2if->base + PS2STAT); + return val & (PS2STAT_KBC | PS2STAT_KBD); +} + +/* + * Test the keyboard interface. We basically check to make sure that + * we can drive each line to the keyboard independently of each other. + */ +static int ps2_test(struct ps2if *ps2if) +{ + unsigned int stat; + int ret = 0; + + stat = ps2_test_one(ps2if, PS2CR_FKC); + if (stat != PS2STAT_KBD) { + printk("PS/2 interface test failed[1]: %02x\n", stat); + ret = -ENODEV; + } + + stat = ps2_test_one(ps2if, 0); + if (stat != (PS2STAT_KBC | PS2STAT_KBD)) { + printk("PS/2 interface test failed[2]: %02x\n", stat); + ret = -ENODEV; + } + + stat = ps2_test_one(ps2if, PS2CR_FKD); + if (stat != PS2STAT_KBC) { + printk("PS/2 interface test failed[3]: %02x\n", stat); + ret = -ENODEV; + } + + writel_relaxed(0, ps2if->base + PS2CR); + + return ret; +} + +/* + * Add one device to this driver. + */ +static int ps2_probe(struct sa1111_dev *dev) +{ + struct ps2if *ps2if; + struct serio *serio; + int ret; + + ps2if = kzalloc(sizeof(struct ps2if), GFP_KERNEL); + serio = kzalloc(sizeof(struct serio), GFP_KERNEL); + if (!ps2if || !serio) { + ret = -ENOMEM; + goto free; + } + + serio->id.type = SERIO_8042; + serio->write = ps2_write; + serio->open = ps2_open; + serio->close = ps2_close; + strscpy(serio->name, dev_name(&dev->dev), sizeof(serio->name)); + strscpy(serio->phys, dev_name(&dev->dev), sizeof(serio->phys)); + serio->port_data = ps2if; + serio->dev.parent = &dev->dev; + ps2if->io = serio; + ps2if->dev = dev; + sa1111_set_drvdata(dev, ps2if); + + spin_lock_init(&ps2if->lock); + + ps2if->rx_irq = sa1111_get_irq(dev, 0); + if (ps2if->rx_irq <= 0) { + ret = ps2if->rx_irq ? : -ENXIO; + goto free; + } + + ps2if->tx_irq = sa1111_get_irq(dev, 1); + if (ps2if->tx_irq <= 0) { + ret = ps2if->tx_irq ? : -ENXIO; + goto free; + } + + /* + * Request the physical region for this PS2 port. + */ + if (!request_mem_region(dev->res.start, + dev->res.end - dev->res.start + 1, + SA1111_DRIVER_NAME(dev))) { + ret = -EBUSY; + goto free; + } + + /* + * Our parent device has already mapped the region. + */ + ps2if->base = dev->mapbase; + + sa1111_enable_device(ps2if->dev); + + /* Incoming clock is 8MHz */ + writel_relaxed(0, ps2if->base + PS2CLKDIV); + writel_relaxed(127, ps2if->base + PS2PRECNT); + + /* + * Flush any pending input. + */ + ps2_clear_input(ps2if); + + /* + * Test the keyboard interface. + */ + ret = ps2_test(ps2if); + if (ret) + goto out; + + /* + * Flush any pending input. + */ + ps2_clear_input(ps2if); + + sa1111_disable_device(ps2if->dev); + serio_register_port(ps2if->io); + return 0; + + out: + sa1111_disable_device(ps2if->dev); + release_mem_region(dev->res.start, resource_size(&dev->res)); + free: + sa1111_set_drvdata(dev, NULL); + kfree(ps2if); + kfree(serio); + return ret; +} + +/* + * Remove one device from this driver. + */ +static void ps2_remove(struct sa1111_dev *dev) +{ + struct ps2if *ps2if = sa1111_get_drvdata(dev); + + serio_unregister_port(ps2if->io); + release_mem_region(dev->res.start, resource_size(&dev->res)); + sa1111_set_drvdata(dev, NULL); + + kfree(ps2if); +} + +/* + * Our device driver structure + */ +static struct sa1111_driver ps2_driver = { + .drv = { + .name = "sa1111-ps2", + .owner = THIS_MODULE, + }, + .devid = SA1111_DEVID_PS2, + .probe = ps2_probe, + .remove = ps2_remove, +}; + +static int __init ps2_init(void) +{ + return sa1111_driver_register(&ps2_driver); +} + +static void __exit ps2_exit(void) +{ + sa1111_driver_unregister(&ps2_driver); +} + +module_init(ps2_init); +module_exit(ps2_exit); + +MODULE_AUTHOR("Russell King <rmk@arm.linux.org.uk>"); +MODULE_DESCRIPTION("SA1111 PS2 controller driver"); +MODULE_LICENSE("GPL"); |