diff options
Diffstat (limited to 'drivers/input/serio/xilinx_ps2.c')
| -rw-r--r-- | drivers/input/serio/xilinx_ps2.c | 371 |
1 files changed, 371 insertions, 0 deletions
diff --git a/drivers/input/serio/xilinx_ps2.c b/drivers/input/serio/xilinx_ps2.c new file mode 100644 index 0000000000..f3d28da70b --- /dev/null +++ b/drivers/input/serio/xilinx_ps2.c @@ -0,0 +1,371 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Xilinx XPS PS/2 device driver + * + * (c) 2005 MontaVista Software, Inc. + * (c) 2008 Xilinx, Inc. + */ + + +#include <linux/module.h> +#include <linux/serio.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/slab.h> +#include <linux/list.h> +#include <linux/io.h> +#include <linux/mod_devicetable.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> + +#define DRIVER_NAME "xilinx_ps2" + +/* Register offsets for the xps2 device */ +#define XPS2_SRST_OFFSET 0x00000000 /* Software Reset register */ +#define XPS2_STATUS_OFFSET 0x00000004 /* Status register */ +#define XPS2_RX_DATA_OFFSET 0x00000008 /* Receive Data register */ +#define XPS2_TX_DATA_OFFSET 0x0000000C /* Transmit Data register */ +#define XPS2_GIER_OFFSET 0x0000002C /* Global Interrupt Enable reg */ +#define XPS2_IPISR_OFFSET 0x00000030 /* Interrupt Status register */ +#define XPS2_IPIER_OFFSET 0x00000038 /* Interrupt Enable register */ + +/* Reset Register Bit Definitions */ +#define XPS2_SRST_RESET 0x0000000A /* Software Reset */ + +/* Status Register Bit Positions */ +#define XPS2_STATUS_RX_FULL 0x00000001 /* Receive Full */ +#define XPS2_STATUS_TX_FULL 0x00000002 /* Transmit Full */ + +/* + * Bit definitions for ISR/IER registers. Both the registers have the same bit + * definitions and are only defined once. + */ +#define XPS2_IPIXR_WDT_TOUT 0x00000001 /* Watchdog Timeout Interrupt */ +#define XPS2_IPIXR_TX_NOACK 0x00000002 /* Transmit No ACK Interrupt */ +#define XPS2_IPIXR_TX_ACK 0x00000004 /* Transmit ACK (Data) Interrupt */ +#define XPS2_IPIXR_RX_OVF 0x00000008 /* Receive Overflow Interrupt */ +#define XPS2_IPIXR_RX_ERR 0x00000010 /* Receive Error Interrupt */ +#define XPS2_IPIXR_RX_FULL 0x00000020 /* Receive Data Interrupt */ + +/* Mask for all the Transmit Interrupts */ +#define XPS2_IPIXR_TX_ALL (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_TX_ACK) + +/* Mask for all the Receive Interrupts */ +#define XPS2_IPIXR_RX_ALL (XPS2_IPIXR_RX_OVF | XPS2_IPIXR_RX_ERR | \ + XPS2_IPIXR_RX_FULL) + +/* Mask for all the Interrupts */ +#define XPS2_IPIXR_ALL (XPS2_IPIXR_TX_ALL | XPS2_IPIXR_RX_ALL | \ + XPS2_IPIXR_WDT_TOUT) + +/* Global Interrupt Enable mask */ +#define XPS2_GIER_GIE_MASK 0x80000000 + +struct xps2data { + int irq; + spinlock_t lock; + void __iomem *base_address; /* virt. address of control registers */ + unsigned int flags; + struct serio *serio; /* serio */ + struct device *dev; +}; + +/************************************/ +/* XPS PS/2 data transmission calls */ +/************************************/ + +/** + * xps2_recv() - attempts to receive a byte from the PS/2 port. + * @drvdata: pointer to ps2 device private data structure + * @byte: address where the read data will be copied + * + * If there is any data available in the PS/2 receiver, this functions reads + * the data, otherwise it returns error. + */ +static int xps2_recv(struct xps2data *drvdata, u8 *byte) +{ + u32 sr; + int status = -1; + + /* If there is data available in the PS/2 receiver, read it */ + sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET); + if (sr & XPS2_STATUS_RX_FULL) { + *byte = in_be32(drvdata->base_address + XPS2_RX_DATA_OFFSET); + status = 0; + } + + return status; +} + +/*********************/ +/* Interrupt handler */ +/*********************/ +static irqreturn_t xps2_interrupt(int irq, void *dev_id) +{ + struct xps2data *drvdata = dev_id; + u32 intr_sr; + u8 c; + int status; + + /* Get the PS/2 interrupts and clear them */ + intr_sr = in_be32(drvdata->base_address + XPS2_IPISR_OFFSET); + out_be32(drvdata->base_address + XPS2_IPISR_OFFSET, intr_sr); + + /* Check which interrupt is active */ + if (intr_sr & XPS2_IPIXR_RX_OVF) + dev_warn(drvdata->dev, "receive overrun error\n"); + + if (intr_sr & XPS2_IPIXR_RX_ERR) + drvdata->flags |= SERIO_PARITY; + + if (intr_sr & (XPS2_IPIXR_TX_NOACK | XPS2_IPIXR_WDT_TOUT)) + drvdata->flags |= SERIO_TIMEOUT; + + if (intr_sr & XPS2_IPIXR_RX_FULL) { + status = xps2_recv(drvdata, &c); + + /* Error, if a byte is not received */ + if (status) { + dev_err(drvdata->dev, + "wrong rcvd byte count (%d)\n", status); + } else { + serio_interrupt(drvdata->serio, c, drvdata->flags); + drvdata->flags = 0; + } + } + + return IRQ_HANDLED; +} + +/*******************/ +/* serio callbacks */ +/*******************/ + +/** + * sxps2_write() - sends a byte out through the PS/2 port. + * @pserio: pointer to the serio structure of the PS/2 port + * @c: data that needs to be written to the PS/2 port + * + * This function checks if the PS/2 transmitter is empty and sends a byte. + * Otherwise it returns error. Transmission fails only when nothing is connected + * to the PS/2 port. Thats why, we do not try to resend the data in case of a + * failure. + */ +static int sxps2_write(struct serio *pserio, unsigned char c) +{ + struct xps2data *drvdata = pserio->port_data; + unsigned long flags; + u32 sr; + int status = -1; + + spin_lock_irqsave(&drvdata->lock, flags); + + /* If the PS/2 transmitter is empty send a byte of data */ + sr = in_be32(drvdata->base_address + XPS2_STATUS_OFFSET); + if (!(sr & XPS2_STATUS_TX_FULL)) { + out_be32(drvdata->base_address + XPS2_TX_DATA_OFFSET, c); + status = 0; + } + + spin_unlock_irqrestore(&drvdata->lock, flags); + + return status; +} + +/** + * sxps2_open() - called when a port is opened by the higher layer. + * @pserio: pointer to the serio structure of the PS/2 device + * + * This function requests irq and enables interrupts for the PS/2 device. + */ +static int sxps2_open(struct serio *pserio) +{ + struct xps2data *drvdata = pserio->port_data; + int error; + u8 c; + + error = request_irq(drvdata->irq, &xps2_interrupt, 0, + DRIVER_NAME, drvdata); + if (error) { + dev_err(drvdata->dev, + "Couldn't allocate interrupt %d\n", drvdata->irq); + return error; + } + + /* start reception by enabling the interrupts */ + out_be32(drvdata->base_address + XPS2_GIER_OFFSET, XPS2_GIER_GIE_MASK); + out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, XPS2_IPIXR_RX_ALL); + (void)xps2_recv(drvdata, &c); + + return 0; /* success */ +} + +/** + * sxps2_close() - frees the interrupt. + * @pserio: pointer to the serio structure of the PS/2 device + * + * This function frees the irq and disables interrupts for the PS/2 device. + */ +static void sxps2_close(struct serio *pserio) +{ + struct xps2data *drvdata = pserio->port_data; + + /* Disable the PS2 interrupts */ + out_be32(drvdata->base_address + XPS2_GIER_OFFSET, 0x00); + out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0x00); + free_irq(drvdata->irq, drvdata); +} + +/** + * xps2_of_probe - probe method for the PS/2 device. + * @of_dev: pointer to OF device structure + * @match: pointer to the structure used for matching a device + * + * This function probes the PS/2 device in the device tree. + * It initializes the driver data structure and the hardware. + * It returns 0, if the driver is bound to the PS/2 device, or a negative + * value if there is an error. + */ +static int xps2_of_probe(struct platform_device *ofdev) +{ + struct resource r_mem; /* IO mem resources */ + struct xps2data *drvdata; + struct serio *serio; + struct device *dev = &ofdev->dev; + resource_size_t remap_size, phys_addr; + unsigned int irq; + int error; + + dev_info(dev, "Device Tree Probing \'%pOFn\'\n", dev->of_node); + + /* Get iospace for the device */ + error = of_address_to_resource(dev->of_node, 0, &r_mem); + if (error) { + dev_err(dev, "invalid address\n"); + return error; + } + + /* Get IRQ for the device */ + irq = irq_of_parse_and_map(dev->of_node, 0); + if (!irq) { + dev_err(dev, "no IRQ found\n"); + return -ENODEV; + } + + drvdata = kzalloc(sizeof(struct xps2data), GFP_KERNEL); + serio = kzalloc(sizeof(struct serio), GFP_KERNEL); + if (!drvdata || !serio) { + error = -ENOMEM; + goto failed1; + } + + spin_lock_init(&drvdata->lock); + drvdata->irq = irq; + drvdata->serio = serio; + drvdata->dev = dev; + + phys_addr = r_mem.start; + remap_size = resource_size(&r_mem); + if (!request_mem_region(phys_addr, remap_size, DRIVER_NAME)) { + dev_err(dev, "Couldn't lock memory region at 0x%08llX\n", + (unsigned long long)phys_addr); + error = -EBUSY; + goto failed1; + } + + /* Fill in configuration data and add them to the list */ + drvdata->base_address = ioremap(phys_addr, remap_size); + if (drvdata->base_address == NULL) { + dev_err(dev, "Couldn't ioremap memory at 0x%08llX\n", + (unsigned long long)phys_addr); + error = -EFAULT; + goto failed2; + } + + /* Disable all the interrupts, just in case */ + out_be32(drvdata->base_address + XPS2_IPIER_OFFSET, 0); + + /* + * Reset the PS2 device and abort any current transaction, + * to make sure we have the PS2 in a good state. + */ + out_be32(drvdata->base_address + XPS2_SRST_OFFSET, XPS2_SRST_RESET); + + dev_info(dev, "Xilinx PS2 at 0x%08llX mapped to 0x%p, irq=%d\n", + (unsigned long long)phys_addr, drvdata->base_address, + drvdata->irq); + + serio->id.type = SERIO_8042; + serio->write = sxps2_write; + serio->open = sxps2_open; + serio->close = sxps2_close; + serio->port_data = drvdata; + serio->dev.parent = dev; + snprintf(serio->name, sizeof(serio->name), + "Xilinx XPS PS/2 at %08llX", (unsigned long long)phys_addr); + snprintf(serio->phys, sizeof(serio->phys), + "xilinxps2/serio at %08llX", (unsigned long long)phys_addr); + + serio_register_port(serio); + + platform_set_drvdata(ofdev, drvdata); + return 0; /* success */ + +failed2: + release_mem_region(phys_addr, remap_size); +failed1: + kfree(serio); + kfree(drvdata); + + return error; +} + +/** + * xps2_of_remove - unbinds the driver from the PS/2 device. + * @of_dev: pointer to OF device structure + * + * This function is called if a device is physically removed from the system or + * if the driver module is being unloaded. It frees any resources allocated to + * the device. + */ +static int xps2_of_remove(struct platform_device *of_dev) +{ + struct xps2data *drvdata = platform_get_drvdata(of_dev); + struct resource r_mem; /* IO mem resources */ + + serio_unregister_port(drvdata->serio); + iounmap(drvdata->base_address); + + /* Get iospace of the device */ + if (of_address_to_resource(of_dev->dev.of_node, 0, &r_mem)) + dev_err(drvdata->dev, "invalid address\n"); + else + release_mem_region(r_mem.start, resource_size(&r_mem)); + + kfree(drvdata); + + return 0; +} + +/* Match table for of_platform binding */ +static const struct of_device_id xps2_of_match[] = { + { .compatible = "xlnx,xps-ps2-1.00.a", }, + { /* end of list */ }, +}; +MODULE_DEVICE_TABLE(of, xps2_of_match); + +static struct platform_driver xps2_of_driver = { + .driver = { + .name = DRIVER_NAME, + .of_match_table = xps2_of_match, + }, + .probe = xps2_of_probe, + .remove = xps2_of_remove, +}; +module_platform_driver(xps2_of_driver); + +MODULE_AUTHOR("Xilinx, Inc."); +MODULE_DESCRIPTION("Xilinx XPS PS/2 driver"); +MODULE_LICENSE("GPL"); + |