1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * SGI IOC3 PS/2 controller driver for linux
  4 *
  5 * Copyright (C) 2019 Thomas Bogendoerfer <tbogendoerfer@suse.de>
  6 *
  7 * Based on code Copyright (C) 2005 Stanislaw Skowronek <skylark@unaligned.org>
  8 *               Copyright (C) 2009 Johannes Dickgreber <tanzy@gmx.de>
  9 */
 10
 11#include <linux/delay.h>
 12#include <linux/init.h>
 13#include <linux/io.h>
 14#include <linux/serio.h>
 15#include <linux/module.h>
 16#include <linux/platform_device.h>
 17
 18#include <asm/sn/ioc3.h>
 19
 20struct ioc3kbd_data {
 21	struct ioc3_serioregs __iomem *regs;
 22	struct serio *kbd, *aux;
 23	bool kbd_exists, aux_exists;
 24	int irq;
 25};
 26
 27static int ioc3kbd_wait(struct ioc3_serioregs __iomem *regs, u32 mask)
 28{
 29	unsigned long timeout = 0;
 30
 31	while ((readl(&regs->km_csr) & mask) && (timeout < 250)) {
 32		udelay(50);
 33		timeout++;
 34	}
 35	return (timeout >= 250) ? -ETIMEDOUT : 0;
 36}
 37
 38static int ioc3kbd_write(struct serio *dev, u8 val)
 39{
 40	struct ioc3kbd_data *d = dev->port_data;
 41	int ret;
 42
 43	ret = ioc3kbd_wait(d->regs, KM_CSR_K_WRT_PEND);
 44	if (ret)
 45		return ret;
 46
 47	writel(val, &d->regs->k_wd);
 48
 49	return 0;
 50}
 51
 52static int ioc3kbd_start(struct serio *dev)
 53{
 54	struct ioc3kbd_data *d = dev->port_data;
 55
 56	d->kbd_exists = true;
 57	return 0;
 58}
 59
 60static void ioc3kbd_stop(struct serio *dev)
 61{
 62	struct ioc3kbd_data *d = dev->port_data;
 63
 64	d->kbd_exists = false;
 65}
 66
 67static int ioc3aux_write(struct serio *dev, u8 val)
 68{
 69	struct ioc3kbd_data *d = dev->port_data;
 70	int ret;
 71
 72	ret = ioc3kbd_wait(d->regs, KM_CSR_M_WRT_PEND);
 73	if (ret)
 74		return ret;
 75
 76	writel(val, &d->regs->m_wd);
 77
 78	return 0;
 79}
 80
 81static int ioc3aux_start(struct serio *dev)
 82{
 83	struct ioc3kbd_data *d = dev->port_data;
 84
 85	d->aux_exists = true;
 86	return 0;
 87}
 88
 89static void ioc3aux_stop(struct serio *dev)
 90{
 91	struct ioc3kbd_data *d = dev->port_data;
 92
 93	d->aux_exists = false;
 94}
 95
 96static void ioc3kbd_process_data(struct serio *dev, u32 data)
 97{
 98	if (data & KM_RD_VALID_0)
 99		serio_interrupt(dev, (data >> KM_RD_DATA_0_SHIFT) & 0xff, 0);
100	if (data & KM_RD_VALID_1)
101		serio_interrupt(dev, (data >> KM_RD_DATA_1_SHIFT) & 0xff, 0);
102	if (data & KM_RD_VALID_2)
103		serio_interrupt(dev, (data >> KM_RD_DATA_2_SHIFT) & 0xff, 0);
104}
105
106static irqreturn_t ioc3kbd_intr(int itq, void *dev_id)
107{
108	struct ioc3kbd_data *d = dev_id;
109	u32 data_k, data_m;
110
111	data_k = readl(&d->regs->k_rd);
112	if (d->kbd_exists)
113		ioc3kbd_process_data(d->kbd, data_k);
114
115	data_m = readl(&d->regs->m_rd);
116	if (d->aux_exists)
117		ioc3kbd_process_data(d->aux, data_m);
118
119	return IRQ_HANDLED;
120}
121
122static int ioc3kbd_probe(struct platform_device *pdev)
123{
124	struct ioc3_serioregs __iomem *regs;
125	struct device *dev = &pdev->dev;
126	struct ioc3kbd_data *d;
127	struct serio *sk, *sa;
128	int irq, ret;
129
130	regs = devm_platform_ioremap_resource(pdev, 0);
131	if (IS_ERR(regs))
132		return PTR_ERR(regs);
133
134	irq = platform_get_irq(pdev, 0);
135	if (irq < 0)
136		return -ENXIO;
137
138	d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL);
139	if (!d)
140		return -ENOMEM;
141
142	sk = kzalloc(sizeof(*sk), GFP_KERNEL);
143	if (!sk)
144		return -ENOMEM;
145
146	sa = kzalloc(sizeof(*sa), GFP_KERNEL);
147	if (!sa) {
148		kfree(sk);
149		return -ENOMEM;
150	}
151
152	sk->id.type = SERIO_8042;
153	sk->write = ioc3kbd_write;
154	sk->start = ioc3kbd_start;
155	sk->stop = ioc3kbd_stop;
156	snprintf(sk->name, sizeof(sk->name), "IOC3 keyboard %d", pdev->id);
157	snprintf(sk->phys, sizeof(sk->phys), "ioc3/serio%dkbd", pdev->id);
158	sk->port_data = d;
159	sk->dev.parent = dev;
160
161	sa->id.type = SERIO_8042;
162	sa->write = ioc3aux_write;
163	sa->start = ioc3aux_start;
164	sa->stop = ioc3aux_stop;
165	snprintf(sa->name, sizeof(sa->name), "IOC3 auxiliary %d", pdev->id);
166	snprintf(sa->phys, sizeof(sa->phys), "ioc3/serio%daux", pdev->id);
167	sa->port_data = d;
168	sa->dev.parent = dev;
169
170	d->regs = regs;
171	d->kbd = sk;
172	d->aux = sa;
173	d->irq = irq;
174
175	platform_set_drvdata(pdev, d);
176	serio_register_port(d->kbd);
177	serio_register_port(d->aux);
178
179	ret = request_irq(irq, ioc3kbd_intr, IRQF_SHARED, "ioc3-kbd", d);
180	if (ret) {
181		dev_err(dev, "could not request IRQ %d\n", irq);
182		serio_unregister_port(d->kbd);
183		serio_unregister_port(d->aux);
184		return ret;
185	}
186
187	/* enable ports */
188	writel(KM_CSR_K_CLAMP_3 | KM_CSR_M_CLAMP_3, &regs->km_csr);
189
190	return 0;
191}
192
193static int ioc3kbd_remove(struct platform_device *pdev)
194{
195	struct ioc3kbd_data *d = platform_get_drvdata(pdev);
196
197	free_irq(d->irq, d);
198
199	serio_unregister_port(d->kbd);
200	serio_unregister_port(d->aux);
201
202	return 0;
203}
204
205static struct platform_driver ioc3kbd_driver = {
206	.probe          = ioc3kbd_probe,
207	.remove         = ioc3kbd_remove,
208	.driver = {
209		.name = "ioc3-kbd",
210	},
211};
212module_platform_driver(ioc3kbd_driver);
213
214MODULE_AUTHOR("Thomas Bogendoerfer <tbogendoerfer@suse.de>");
215MODULE_DESCRIPTION("SGI IOC3 serio driver");
216MODULE_LICENSE("GPL");