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