1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Technologic Systems TS-5500 Single Board Computer support
4 *
5 * Copyright (C) 2013-2014 Savoir-faire Linux Inc.
6 *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
7 *
8 * This driver registers the Technologic Systems TS-5500 Single Board Computer
9 * (SBC) and its devices, and exposes information to userspace such as jumpers'
10 * state or available options. For further information about sysfs entries, see
11 * Documentation/ABI/testing/sysfs-platform-ts5500.
12 *
13 * This code may be extended to support similar x86-based platforms.
14 * Actually, the TS-5500 and TS-5400 are supported.
15 */
16
17#include <linux/delay.h>
18#include <linux/io.h>
19#include <linux/kernel.h>
20#include <linux/leds.h>
21#include <linux/init.h>
22#include <linux/platform_data/max197.h>
23#include <linux/platform_device.h>
24#include <linux/slab.h>
25
26/* Product code register */
27#define TS5500_PRODUCT_CODE_ADDR	0x74
28#define TS5500_PRODUCT_CODE		0x60	/* TS-5500 product code */
29#define TS5400_PRODUCT_CODE		0x40	/* TS-5400 product code */
30
31/* SRAM/RS-485/ADC options, and RS-485 RTS/Automatic RS-485 flags register */
32#define TS5500_SRAM_RS485_ADC_ADDR	0x75
33#define TS5500_SRAM			BIT(0)	/* SRAM option */
34#define TS5500_RS485			BIT(1)	/* RS-485 option */
35#define TS5500_ADC			BIT(2)	/* A/D converter option */
36#define TS5500_RS485_RTS		BIT(6)	/* RTS for RS-485 */
37#define TS5500_RS485_AUTO		BIT(7)	/* Automatic RS-485 */
38
39/* External Reset/Industrial Temperature Range options register */
40#define TS5500_ERESET_ITR_ADDR		0x76
41#define TS5500_ERESET			BIT(0)	/* External Reset option */
42#define TS5500_ITR			BIT(1)	/* Indust. Temp. Range option */
43
44/* LED/Jumpers register */
45#define TS5500_LED_JP_ADDR		0x77
46#define TS5500_LED			BIT(0)	/* LED flag */
47#define TS5500_JP1			BIT(1)	/* Automatic CMOS */
48#define TS5500_JP2			BIT(2)	/* Enable Serial Console */
49#define TS5500_JP3			BIT(3)	/* Write Enable Drive A */
50#define TS5500_JP4			BIT(4)	/* Fast Console (115K baud) */
51#define TS5500_JP5			BIT(5)	/* User Jumper */
52#define TS5500_JP6			BIT(6)	/* Console on COM1 (req. JP2) */
53#define TS5500_JP7			BIT(7)	/* Undocumented (Unused) */
54
55/* A/D Converter registers */
56#define TS5500_ADC_CONV_BUSY_ADDR	0x195	/* Conversion state register */
57#define TS5500_ADC_CONV_BUSY		BIT(0)
58#define TS5500_ADC_CONV_INIT_LSB_ADDR	0x196	/* Start conv. / LSB register */
59#define TS5500_ADC_CONV_MSB_ADDR	0x197	/* MSB register */
60#define TS5500_ADC_CONV_DELAY		12	/* usec */
61
62/**
63 * struct ts5500_sbc - TS-5500 board description
64 * @name:	Board model name.
65 * @id:		Board product ID.
66 * @sram:	Flag for SRAM option.
67 * @rs485:	Flag for RS-485 option.
68 * @adc:	Flag for Analog/Digital converter option.
69 * @ereset:	Flag for External Reset option.
70 * @itr:	Flag for Industrial Temperature Range option.
71 * @jumpers:	Bitfield for jumpers' state.
72 */
73struct ts5500_sbc {
74	const char *name;
75	int	id;
76	bool	sram;
77	bool	rs485;
78	bool	adc;
79	bool	ereset;
80	bool	itr;
81	u8	jumpers;
82};
83
84/* Board signatures in BIOS shadow RAM */
85static const struct {
86	const char * const string;
87	const ssize_t offset;
88} ts5500_signatures[] __initconst = {
89	{ "TS-5x00 AMD Elan", 0xb14 },
90};
91
92static int __init ts5500_check_signature(void)
93{
94	void __iomem *bios;
95	int i, ret = -ENODEV;
96
97	bios = ioremap(0xf0000, 0x10000);
98	if (!bios)
99		return -ENOMEM;
100
101	for (i = 0; i < ARRAY_SIZE(ts5500_signatures); i++) {
102		if (check_signature(bios + ts5500_signatures[i].offset,
103				    ts5500_signatures[i].string,
104				    strlen(ts5500_signatures[i].string))) {
105			ret = 0;
106			break;
107		}
108	}
109
110	iounmap(bios);
111	return ret;
112}
113
114static int __init ts5500_detect_config(struct ts5500_sbc *sbc)
115{
116	u8 tmp;
117	int ret = 0;
118
119	if (!request_region(TS5500_PRODUCT_CODE_ADDR, 4, "ts5500"))
120		return -EBUSY;
121
122	sbc->id = inb(TS5500_PRODUCT_CODE_ADDR);
123	if (sbc->id == TS5500_PRODUCT_CODE) {
124		sbc->name = "TS-5500";
125	} else if (sbc->id == TS5400_PRODUCT_CODE) {
126		sbc->name = "TS-5400";
127	} else {
128		pr_err("ts5500: unknown product code 0x%x\n", sbc->id);
129		ret = -ENODEV;
130		goto cleanup;
131	}
132
133	tmp = inb(TS5500_SRAM_RS485_ADC_ADDR);
134	sbc->sram = tmp & TS5500_SRAM;
135	sbc->rs485 = tmp & TS5500_RS485;
136	sbc->adc = tmp & TS5500_ADC;
137
138	tmp = inb(TS5500_ERESET_ITR_ADDR);
139	sbc->ereset = tmp & TS5500_ERESET;
140	sbc->itr = tmp & TS5500_ITR;
141
142	tmp = inb(TS5500_LED_JP_ADDR);
143	sbc->jumpers = tmp & ~TS5500_LED;
144
145cleanup:
146	release_region(TS5500_PRODUCT_CODE_ADDR, 4);
147	return ret;
148}
149
150static ssize_t name_show(struct device *dev, struct device_attribute *attr,
151		char *buf)
152{
153	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
154
155	return sprintf(buf, "%s\n", sbc->name);
156}
157static DEVICE_ATTR_RO(name);
158
159static ssize_t id_show(struct device *dev, struct device_attribute *attr,
160		char *buf)
161{
162	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
163
164	return sprintf(buf, "0x%.2x\n", sbc->id);
165}
166static DEVICE_ATTR_RO(id);
167
168static ssize_t jumpers_show(struct device *dev, struct device_attribute *attr,
169		char *buf)
170{
171	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
172
173	return sprintf(buf, "0x%.2x\n", sbc->jumpers >> 1);
174}
175static DEVICE_ATTR_RO(jumpers);
176
177#define TS5500_ATTR_BOOL(_field)					\
178	static ssize_t _field##_show(struct device *dev,		\
179			struct device_attribute *attr, char *buf)	\
180	{								\
181		struct ts5500_sbc *sbc = dev_get_drvdata(dev);		\
182									\
183		return sprintf(buf, "%d\n", sbc->_field);		\
184	}								\
185	static DEVICE_ATTR_RO(_field)
186
187TS5500_ATTR_BOOL(sram);
188TS5500_ATTR_BOOL(rs485);
189TS5500_ATTR_BOOL(adc);
190TS5500_ATTR_BOOL(ereset);
191TS5500_ATTR_BOOL(itr);
192
193static struct attribute *ts5500_attributes[] = {
194	&dev_attr_id.attr,
195	&dev_attr_name.attr,
196	&dev_attr_jumpers.attr,
197	&dev_attr_sram.attr,
198	&dev_attr_rs485.attr,
199	&dev_attr_adc.attr,
200	&dev_attr_ereset.attr,
201	&dev_attr_itr.attr,
202	NULL
203};
204
205static const struct attribute_group ts5500_attr_group = {
206	.attrs = ts5500_attributes,
207};
208
209static struct resource ts5500_dio1_resource[] = {
210	DEFINE_RES_IRQ_NAMED(7, "DIO1 interrupt"),
211};
212
213static struct platform_device ts5500_dio1_pdev = {
214	.name = "ts5500-dio1",
215	.id = -1,
216	.resource = ts5500_dio1_resource,
217	.num_resources = 1,
218};
219
220static struct resource ts5500_dio2_resource[] = {
221	DEFINE_RES_IRQ_NAMED(6, "DIO2 interrupt"),
222};
223
224static struct platform_device ts5500_dio2_pdev = {
225	.name = "ts5500-dio2",
226	.id = -1,
227	.resource = ts5500_dio2_resource,
228	.num_resources = 1,
229};
230
231static void ts5500_led_set(struct led_classdev *led_cdev,
232			   enum led_brightness brightness)
233{
234	outb(!!brightness, TS5500_LED_JP_ADDR);
235}
236
237static enum led_brightness ts5500_led_get(struct led_classdev *led_cdev)
238{
239	return (inb(TS5500_LED_JP_ADDR) & TS5500_LED) ? LED_FULL : LED_OFF;
240}
241
242static struct led_classdev ts5500_led_cdev = {
243	.name = "ts5500:green:",
244	.brightness_set = ts5500_led_set,
245	.brightness_get = ts5500_led_get,
246};
247
248static int ts5500_adc_convert(u8 ctrl)
249{
250	u8 lsb, msb;
251
252	/* Start conversion (ensure the 3 MSB are set to 0) */
253	outb(ctrl & 0x1f, TS5500_ADC_CONV_INIT_LSB_ADDR);
254
255	/*
256	 * The platform has CPLD logic driving the A/D converter.
257	 * The conversion must complete within 11 microseconds,
258	 * otherwise we have to re-initiate a conversion.
259	 */
260	udelay(TS5500_ADC_CONV_DELAY);
261	if (inb(TS5500_ADC_CONV_BUSY_ADDR) & TS5500_ADC_CONV_BUSY)
262		return -EBUSY;
263
264	/* Read the raw data */
265	lsb = inb(TS5500_ADC_CONV_INIT_LSB_ADDR);
266	msb = inb(TS5500_ADC_CONV_MSB_ADDR);
267
268	return (msb << 8) | lsb;
269}
270
271static struct max197_platform_data ts5500_adc_pdata = {
272	.convert = ts5500_adc_convert,
273};
274
275static struct platform_device ts5500_adc_pdev = {
276	.name = "max197",
277	.id = -1,
278	.dev = {
279		.platform_data = &ts5500_adc_pdata,
280	},
281};
282
283static int __init ts5500_init(void)
284{
285	struct platform_device *pdev;
286	struct ts5500_sbc *sbc;
287	int err;
288
289	/*
290	 * There is no DMI available or PCI bridge subvendor info,
291	 * only the BIOS provides a 16-bit identification call.
292	 * It is safer to find a signature in the BIOS shadow RAM.
293	 */
294	err = ts5500_check_signature();
295	if (err)
296		return err;
297
298	pdev = platform_device_register_simple("ts5500", -1, NULL, 0);
299	if (IS_ERR(pdev))
300		return PTR_ERR(pdev);
301
302	sbc = devm_kzalloc(&pdev->dev, sizeof(struct ts5500_sbc), GFP_KERNEL);
303	if (!sbc) {
304		err = -ENOMEM;
305		goto error;
306	}
307
308	err = ts5500_detect_config(sbc);
309	if (err)
310		goto error;
311
312	platform_set_drvdata(pdev, sbc);
313
314	err = sysfs_create_group(&pdev->dev.kobj, &ts5500_attr_group);
315	if (err)
316		goto error;
317
318	if (sbc->id == TS5500_PRODUCT_CODE) {
319		ts5500_dio1_pdev.dev.parent = &pdev->dev;
320		if (platform_device_register(&ts5500_dio1_pdev))
321			dev_warn(&pdev->dev, "DIO1 block registration failed\n");
322		ts5500_dio2_pdev.dev.parent = &pdev->dev;
323		if (platform_device_register(&ts5500_dio2_pdev))
324			dev_warn(&pdev->dev, "DIO2 block registration failed\n");
325	}
326
327	if (led_classdev_register(&pdev->dev, &ts5500_led_cdev))
328		dev_warn(&pdev->dev, "LED registration failed\n");
329
330	if (sbc->adc) {
331		ts5500_adc_pdev.dev.parent = &pdev->dev;
332		if (platform_device_register(&ts5500_adc_pdev))
333			dev_warn(&pdev->dev, "ADC registration failed\n");
334	}
335
336	return 0;
337error:
338	platform_device_unregister(pdev);
339	return err;
340}
341device_initcall(ts5500_init);
342