1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * PXA930 track ball mouse driver
  4 *
  5 * Copyright (C) 2007 Marvell International Ltd.
  6 * 2008-02-28: Yong Yao <yaoyong@marvell.com>
  7 *             initial version
  8 */
  9
 10#include <linux/input.h>
 11#include <linux/interrupt.h>
 12#include <linux/module.h>
 13#include <linux/platform_device.h>
 14#include <linux/delay.h>
 15#include <linux/io.h>
 16#include <linux/slab.h>
 17
 18#include <mach/hardware.h>
 19#include <linux/platform_data/mouse-pxa930_trkball.h>
 20
 21/* Trackball Controller Register Definitions */
 22#define TBCR		(0x000C)
 23#define TBCNTR		(0x0010)
 24#define TBSBC		(0x0014)
 25
 26#define TBCR_TBRST	(1 << 1)
 27#define TBCR_TBSB	(1 << 10)
 28
 29#define TBCR_Y_FLT(n)	(((n) & 0xf) << 6)
 30#define TBCR_X_FLT(n)	(((n) & 0xf) << 2)
 31
 32#define TBCNTR_YM(n)	(((n) >> 24) & 0xff)
 33#define TBCNTR_YP(n)	(((n) >> 16) & 0xff)
 34#define TBCNTR_XM(n)	(((n) >> 8) & 0xff)
 35#define TBCNTR_XP(n)	((n) & 0xff)
 36
 37#define TBSBC_TBSBC	(0x1)
 38
 39struct pxa930_trkball {
 40	struct pxa930_trkball_platform_data *pdata;
 41
 42	/* Memory Mapped Register */
 43	struct resource *mem;
 44	void __iomem *mmio_base;
 45
 46	struct input_dev *input;
 47};
 48
 49static irqreturn_t pxa930_trkball_interrupt(int irq, void *dev_id)
 50{
 51	struct pxa930_trkball *trkball = dev_id;
 52	struct input_dev *input = trkball->input;
 53	int tbcntr, x, y;
 54
 55	/* According to the spec software must read TBCNTR twice:
 56	 * if the read value is the same, the reading is valid
 57	 */
 58	tbcntr = __raw_readl(trkball->mmio_base + TBCNTR);
 59
 60	if (tbcntr == __raw_readl(trkball->mmio_base + TBCNTR)) {
 61		x = (TBCNTR_XP(tbcntr) - TBCNTR_XM(tbcntr)) / 2;
 62		y = (TBCNTR_YP(tbcntr) - TBCNTR_YM(tbcntr)) / 2;
 63
 64		input_report_rel(input, REL_X, x);
 65		input_report_rel(input, REL_Y, y);
 66		input_sync(input);
 67	}
 68
 69	__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
 70	__raw_writel(0, trkball->mmio_base + TBSBC);
 71
 72	return IRQ_HANDLED;
 73}
 74
 75/* For TBCR, we need to wait for a while to make sure it has been modified. */
 76static int write_tbcr(struct pxa930_trkball *trkball, int v)
 77{
 78	int i = 100;
 79
 80	__raw_writel(v, trkball->mmio_base + TBCR);
 81
 82	while (--i) {
 83		if (__raw_readl(trkball->mmio_base + TBCR) == v)
 84			break;
 85		msleep(1);
 86	}
 87
 88	if (i == 0) {
 89		pr_err("%s: timed out writing TBCR(%x)!\n", __func__, v);
 90		return -ETIMEDOUT;
 91	}
 92
 93	return 0;
 94}
 95
 96static void pxa930_trkball_config(struct pxa930_trkball *trkball)
 97{
 98	uint32_t tbcr;
 99
100	/* According to spec, need to write the filters of x,y to 0xf first! */
101	tbcr = __raw_readl(trkball->mmio_base + TBCR);
102	write_tbcr(trkball, tbcr | TBCR_X_FLT(0xf) | TBCR_Y_FLT(0xf));
103	write_tbcr(trkball, TBCR_X_FLT(trkball->pdata->x_filter) |
104			    TBCR_Y_FLT(trkball->pdata->y_filter));
105
106	/* According to spec, set TBCR_TBRST first, before clearing it! */
107	tbcr = __raw_readl(trkball->mmio_base + TBCR);
108	write_tbcr(trkball, tbcr | TBCR_TBRST);
109	write_tbcr(trkball, tbcr & ~TBCR_TBRST);
110
111	__raw_writel(TBSBC_TBSBC, trkball->mmio_base + TBSBC);
112	__raw_writel(0, trkball->mmio_base + TBSBC);
113
114	pr_debug("%s: final TBCR=%x!\n", __func__,
115		 __raw_readl(trkball->mmio_base + TBCR));
116}
117
118static int pxa930_trkball_open(struct input_dev *dev)
119{
120	struct pxa930_trkball *trkball = input_get_drvdata(dev);
121
122	pxa930_trkball_config(trkball);
123
124	return 0;
125}
126
127static void pxa930_trkball_disable(struct pxa930_trkball *trkball)
128{
129	uint32_t tbcr = __raw_readl(trkball->mmio_base + TBCR);
130
131	/* Held in reset, gate the 32-KHz input clock off */
132	write_tbcr(trkball, tbcr | TBCR_TBRST);
133}
134
135static void pxa930_trkball_close(struct input_dev *dev)
136{
137	struct pxa930_trkball *trkball = input_get_drvdata(dev);
138
139	pxa930_trkball_disable(trkball);
140}
141
142static int pxa930_trkball_probe(struct platform_device *pdev)
143{
144	struct pxa930_trkball *trkball;
145	struct input_dev *input;
146	struct resource *res;
147	int irq, error;
148
149	irq = platform_get_irq(pdev, 0);
150	if (irq < 0)
151		return -ENXIO;
152
153	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
154	if (!res) {
155		dev_err(&pdev->dev, "failed to get register memory\n");
156		return -ENXIO;
157	}
158
159	trkball = kzalloc(sizeof(struct pxa930_trkball), GFP_KERNEL);
160	if (!trkball)
161		return -ENOMEM;
162
163	trkball->pdata = dev_get_platdata(&pdev->dev);
164	if (!trkball->pdata) {
165		dev_err(&pdev->dev, "no platform data defined\n");
166		error = -EINVAL;
167		goto failed;
168	}
169
170	trkball->mmio_base = ioremap(res->start, resource_size(res));
171	if (!trkball->mmio_base) {
172		dev_err(&pdev->dev, "failed to ioremap registers\n");
173		error = -ENXIO;
174		goto failed;
175	}
176
177	/* held the module in reset, will be enabled in open() */
178	pxa930_trkball_disable(trkball);
179
180	error = request_irq(irq, pxa930_trkball_interrupt, 0,
181			    pdev->name, trkball);
182	if (error) {
183		dev_err(&pdev->dev, "failed to request irq: %d\n", error);
184		goto failed_free_io;
185	}
186
187	platform_set_drvdata(pdev, trkball);
188
189	input = input_allocate_device();
190	if (!input) {
191		dev_err(&pdev->dev, "failed to allocate input device\n");
192		error = -ENOMEM;
193		goto failed_free_irq;
194	}
195
196	input->name = pdev->name;
197	input->id.bustype = BUS_HOST;
198	input->open = pxa930_trkball_open;
199	input->close = pxa930_trkball_close;
200	input->dev.parent = &pdev->dev;
201	input_set_drvdata(input, trkball);
202
203	trkball->input = input;
204
205	input_set_capability(input, EV_REL, REL_X);
206	input_set_capability(input, EV_REL, REL_Y);
207
208	error = input_register_device(input);
209	if (error) {
210		dev_err(&pdev->dev, "unable to register input device\n");
211		goto failed_free_input;
212	}
213
214	return 0;
215
216failed_free_input:
217	input_free_device(input);
218failed_free_irq:
219	free_irq(irq, trkball);
220failed_free_io:
221	iounmap(trkball->mmio_base);
222failed:
223	kfree(trkball);
224	return error;
225}
226
227static int pxa930_trkball_remove(struct platform_device *pdev)
228{
229	struct pxa930_trkball *trkball = platform_get_drvdata(pdev);
230	int irq = platform_get_irq(pdev, 0);
231
232	input_unregister_device(trkball->input);
233	free_irq(irq, trkball);
234	iounmap(trkball->mmio_base);
235	kfree(trkball);
236
237	return 0;
238}
239
240static struct platform_driver pxa930_trkball_driver = {
241	.driver		= {
242		.name	= "pxa930-trkball",
243	},
244	.probe		= pxa930_trkball_probe,
245	.remove		= pxa930_trkball_remove,
246};
247module_platform_driver(pxa930_trkball_driver);
248
249MODULE_AUTHOR("Yong Yao <yaoyong@marvell.com>");
250MODULE_DESCRIPTION("PXA930 Trackball Mouse Driver");
251MODULE_LICENSE("GPL");