// SPDX-License-Identifier: GPL-2.0-or-later /* * Xilinx XPS PS/2 device driver * * (c) 2005 MontaVista Software, Inc. * (c) 2008 Xilinx, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #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");