1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Support Infineon TLE62x0 driver chips
4 *
5 * Copyright (c) 2007 Simtec Electronics
6 *	Ben Dooks, <ben@simtec.co.uk>
7 */
8
9#include <linux/device.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/slab.h>
13
14#include <linux/spi/spi.h>
15#include <linux/spi/tle62x0.h>
16
17
18#define CMD_READ	0x00
19#define CMD_SET		0xff
20
21#define DIAG_NORMAL	0x03
22#define DIAG_OVERLOAD	0x02
23#define DIAG_OPEN	0x01
24#define DIAG_SHORTGND	0x00
25
26struct tle62x0_state {
27	struct spi_device	*us;
28	struct mutex		lock;
29	unsigned int		nr_gpio;
30	unsigned int		gpio_state;
31
32	unsigned char		tx_buff[4];
33	unsigned char		rx_buff[4];
34};
35
36static int to_gpio_num(struct device_attribute *attr);
37
38static inline int tle62x0_write(struct tle62x0_state *st)
39{
40	unsigned char *buff = st->tx_buff;
41	unsigned int gpio_state = st->gpio_state;
42
43	buff[0] = CMD_SET;
44
45	if (st->nr_gpio == 16) {
46		buff[1] = gpio_state >> 8;
47		buff[2] = gpio_state;
48	} else {
49		buff[1] = gpio_state;
50	}
51
52	dev_dbg(&st->us->dev, "buff %3ph\n", buff);
53
54	return spi_write(st->us, buff, (st->nr_gpio == 16) ? 3 : 2);
55}
56
57static inline int tle62x0_read(struct tle62x0_state *st)
58{
59	unsigned char *txbuff = st->tx_buff;
60	struct spi_transfer xfer = {
61		.tx_buf		= txbuff,
62		.rx_buf		= st->rx_buff,
63		.len		= (st->nr_gpio * 2) / 8,
64	};
65	struct spi_message msg;
66
67	txbuff[0] = CMD_READ;
68	txbuff[1] = 0x00;
69	txbuff[2] = 0x00;
70	txbuff[3] = 0x00;
71
72	spi_message_init(&msg);
73	spi_message_add_tail(&xfer, &msg);
74
75	return spi_sync(st->us, &msg);
76}
77
78static unsigned char *decode_fault(unsigned int fault_code)
79{
80	fault_code &= 3;
81
82	switch (fault_code) {
83	case DIAG_NORMAL:
84		return "N";
85	case DIAG_OVERLOAD:
86		return "V";
87	case DIAG_OPEN:
88		return "O";
89	case DIAG_SHORTGND:
90		return "G";
91	}
92
93	return "?";
94}
95
96static ssize_t tle62x0_status_show(struct device *dev,
97		struct device_attribute *attr, char *buf)
98{
99	struct tle62x0_state *st = dev_get_drvdata(dev);
100	char *bp = buf;
101	unsigned char *buff = st->rx_buff;
102	unsigned long fault = 0;
103	int ptr;
104	int ret;
105
106	mutex_lock(&st->lock);
107	ret = tle62x0_read(st);
108	dev_dbg(dev, "tle62x0_read() returned %d\n", ret);
109	if (ret < 0) {
110		mutex_unlock(&st->lock);
111		return ret;
112	}
113
114	for (ptr = 0; ptr < (st->nr_gpio * 2)/8; ptr += 1) {
115		fault <<= 8;
116		fault  |= ((unsigned long)buff[ptr]);
117
118		dev_dbg(dev, "byte %d is %02x\n", ptr, buff[ptr]);
119	}
120
121	for (ptr = 0; ptr < st->nr_gpio; ptr++) {
122		bp += sprintf(bp, "%s ", decode_fault(fault >> (ptr * 2)));
123	}
124
125	*bp++ = '\n';
126
127	mutex_unlock(&st->lock);
128	return bp - buf;
129}
130
131static DEVICE_ATTR(status_show, S_IRUGO, tle62x0_status_show, NULL);
132
133static ssize_t tle62x0_gpio_show(struct device *dev,
134		struct device_attribute *attr, char *buf)
135{
136	struct tle62x0_state *st = dev_get_drvdata(dev);
137	int gpio_num = to_gpio_num(attr);
138	int value;
139
140	mutex_lock(&st->lock);
141	value = (st->gpio_state >> gpio_num) & 1;
142	mutex_unlock(&st->lock);
143
144	return sysfs_emit(buf, "%d", value);
145}
146
147static ssize_t tle62x0_gpio_store(struct device *dev,
148		struct device_attribute *attr,
149		const char *buf, size_t len)
150{
151	struct tle62x0_state *st = dev_get_drvdata(dev);
152	int gpio_num = to_gpio_num(attr);
153	unsigned long val;
154	char *endp;
155
156	val = simple_strtoul(buf, &endp, 0);
157	if (buf == endp)
158		return -EINVAL;
159
160	dev_dbg(dev, "setting gpio %d to %ld\n", gpio_num, val);
161
162	mutex_lock(&st->lock);
163
164	if (val)
165		st->gpio_state |= 1 << gpio_num;
166	else
167		st->gpio_state &= ~(1 << gpio_num);
168
169	tle62x0_write(st);
170	mutex_unlock(&st->lock);
171
172	return len;
173}
174
175static DEVICE_ATTR(gpio1, S_IWUSR|S_IRUGO,
176		tle62x0_gpio_show, tle62x0_gpio_store);
177static DEVICE_ATTR(gpio2, S_IWUSR|S_IRUGO,
178		tle62x0_gpio_show, tle62x0_gpio_store);
179static DEVICE_ATTR(gpio3, S_IWUSR|S_IRUGO,
180		tle62x0_gpio_show, tle62x0_gpio_store);
181static DEVICE_ATTR(gpio4, S_IWUSR|S_IRUGO,
182		tle62x0_gpio_show, tle62x0_gpio_store);
183static DEVICE_ATTR(gpio5, S_IWUSR|S_IRUGO,
184		tle62x0_gpio_show, tle62x0_gpio_store);
185static DEVICE_ATTR(gpio6, S_IWUSR|S_IRUGO,
186		tle62x0_gpio_show, tle62x0_gpio_store);
187static DEVICE_ATTR(gpio7, S_IWUSR|S_IRUGO,
188		tle62x0_gpio_show, tle62x0_gpio_store);
189static DEVICE_ATTR(gpio8, S_IWUSR|S_IRUGO,
190		tle62x0_gpio_show, tle62x0_gpio_store);
191static DEVICE_ATTR(gpio9, S_IWUSR|S_IRUGO,
192		tle62x0_gpio_show, tle62x0_gpio_store);
193static DEVICE_ATTR(gpio10, S_IWUSR|S_IRUGO,
194		tle62x0_gpio_show, tle62x0_gpio_store);
195static DEVICE_ATTR(gpio11, S_IWUSR|S_IRUGO,
196		tle62x0_gpio_show, tle62x0_gpio_store);
197static DEVICE_ATTR(gpio12, S_IWUSR|S_IRUGO,
198		tle62x0_gpio_show, tle62x0_gpio_store);
199static DEVICE_ATTR(gpio13, S_IWUSR|S_IRUGO,
200		tle62x0_gpio_show, tle62x0_gpio_store);
201static DEVICE_ATTR(gpio14, S_IWUSR|S_IRUGO,
202		tle62x0_gpio_show, tle62x0_gpio_store);
203static DEVICE_ATTR(gpio15, S_IWUSR|S_IRUGO,
204		tle62x0_gpio_show, tle62x0_gpio_store);
205static DEVICE_ATTR(gpio16, S_IWUSR|S_IRUGO,
206		tle62x0_gpio_show, tle62x0_gpio_store);
207
208static struct device_attribute *gpio_attrs[] = {
209	[0]		= &dev_attr_gpio1,
210	[1]		= &dev_attr_gpio2,
211	[2]		= &dev_attr_gpio3,
212	[3]		= &dev_attr_gpio4,
213	[4]		= &dev_attr_gpio5,
214	[5]		= &dev_attr_gpio6,
215	[6]		= &dev_attr_gpio7,
216	[7]		= &dev_attr_gpio8,
217	[8]		= &dev_attr_gpio9,
218	[9]		= &dev_attr_gpio10,
219	[10]		= &dev_attr_gpio11,
220	[11]		= &dev_attr_gpio12,
221	[12]		= &dev_attr_gpio13,
222	[13]		= &dev_attr_gpio14,
223	[14]		= &dev_attr_gpio15,
224	[15]		= &dev_attr_gpio16
225};
226
227static int to_gpio_num(struct device_attribute *attr)
228{
229	int ptr;
230
231	for (ptr = 0; ptr < ARRAY_SIZE(gpio_attrs); ptr++) {
232		if (gpio_attrs[ptr] == attr)
233			return ptr;
234	}
235
236	return -1;
237}
238
239static int tle62x0_probe(struct spi_device *spi)
240{
241	struct tle62x0_state *st;
242	struct tle62x0_pdata *pdata;
243	int ptr;
244	int ret;
245
246	pdata = dev_get_platdata(&spi->dev);
247	if (pdata == NULL) {
248		dev_err(&spi->dev, "no device data specified\n");
249		return -EINVAL;
250	}
251
252	st = kzalloc(sizeof(struct tle62x0_state), GFP_KERNEL);
253	if (st == NULL)
254		return -ENOMEM;
255
256	st->us = spi;
257	st->nr_gpio = pdata->gpio_count;
258	st->gpio_state = pdata->init_state;
259
260	mutex_init(&st->lock);
261
262	ret = device_create_file(&spi->dev, &dev_attr_status_show);
263	if (ret) {
264		dev_err(&spi->dev, "cannot create status attribute\n");
265		goto err_status;
266	}
267
268	for (ptr = 0; ptr < pdata->gpio_count; ptr++) {
269		ret = device_create_file(&spi->dev, gpio_attrs[ptr]);
270		if (ret) {
271			dev_err(&spi->dev, "cannot create gpio attribute\n");
272			goto err_gpios;
273		}
274	}
275
276	/* tle62x0_write(st); */
277	spi_set_drvdata(spi, st);
278	return 0;
279
280 err_gpios:
281	while (--ptr >= 0)
282		device_remove_file(&spi->dev, gpio_attrs[ptr]);
283
284	device_remove_file(&spi->dev, &dev_attr_status_show);
285
286 err_status:
287	kfree(st);
288	return ret;
289}
290
291static void tle62x0_remove(struct spi_device *spi)
292{
293	struct tle62x0_state *st = spi_get_drvdata(spi);
294	int ptr;
295
296	for (ptr = 0; ptr < st->nr_gpio; ptr++)
297		device_remove_file(&spi->dev, gpio_attrs[ptr]);
298
299	device_remove_file(&spi->dev, &dev_attr_status_show);
300	kfree(st);
301}
302
303static struct spi_driver tle62x0_driver = {
304	.driver = {
305		.name	= "tle62x0",
306	},
307	.probe		= tle62x0_probe,
308	.remove		= tle62x0_remove,
309};
310
311module_spi_driver(tle62x0_driver);
312
313MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>");
314MODULE_DESCRIPTION("TLE62x0 SPI driver");
315MODULE_LICENSE("GPL v2");
316MODULE_ALIAS("spi:tle62x0");
317