// SPDX-License-Identifier: GPL-2.0-or-later /* * OLPC serio driver for multiplexed input from Marvell MMP security processor * * Copyright (C) 2011-2013 One Laptop Per Child */ #include <linux/module.h> #include <linux/interrupt.h> #include <linux/serio.h> #include <linux/err.h> #include <linux/platform_device.h> #include <linux/io.h> #include <linux/of.h> #include <linux/slab.h> #include <linux/delay.h> /* * The OLPC XO-1.75 and XO-4 laptops do not have a hardware PS/2 controller. * Instead, the OLPC firmware runs a bit-banging PS/2 implementation on an * otherwise-unused slow processor which is included in the Marvell MMP2/MMP3 * SoC, known as the "Security Processor" (SP) or "Wireless Trusted Module" * (WTM). This firmware then reports its results via the WTM registers, * which we read from the Application Processor (AP, i.e. main CPU) in this * driver. * * On the hardware side we have a PS/2 mouse and an AT keyboard, the data * is multiplexed through this system. We create a serio port for each one, * and demultiplex the data accordingly. */ /* WTM register offsets */ #define SECURE_PROCESSOR_COMMAND … #define COMMAND_RETURN_STATUS … #define COMMAND_FIFO_STATUS … #define PJ_RST_INTERRUPT … #define PJ_INTERRUPT_MASK … /* * The upper byte of SECURE_PROCESSOR_COMMAND and COMMAND_RETURN_STATUS is * used to identify which port (device) is being talked to. The lower byte * is the data being sent/received. */ #define PORT_MASK … #define DATA_MASK … #define PORT_SHIFT … #define KEYBOARD_PORT … #define TOUCHPAD_PORT … /* COMMAND_FIFO_STATUS */ #define CMD_CNTR_MASK … #define MAX_PENDING_CMDS … /* PJ_RST_INTERRUPT */ #define SP_COMMAND_COMPLETE_RESET … /* PJ_INTERRUPT_MASK */ #define INT_0 … /* COMMAND_FIFO_STATUS */ #define CMD_STS_MASK … struct olpc_apsp { … }; static int olpc_apsp_write(struct serio *port, unsigned char val) { … } static irqreturn_t olpc_apsp_rx(int irq, void *dev_id) { … } static int olpc_apsp_open(struct serio *port) { … } static void olpc_apsp_close(struct serio *port) { … } static int olpc_apsp_probe(struct platform_device *pdev) { … } static void olpc_apsp_remove(struct platform_device *pdev) { … } static const struct of_device_id olpc_apsp_dt_ids[] = …; MODULE_DEVICE_TABLE(of, olpc_apsp_dt_ids); static struct platform_driver olpc_apsp_driver = …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; module_platform_driver(…) …;
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