xref: /linux/arch/x86/platform/ts5500/ts5500.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * Technologic Systems TS-5500 Single Board Computer support
3  *
4  * Copyright (C) 2013-2014 Savoir-faire Linux Inc.
5  *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
6  *
7  * This program is free software; you can redistribute it and/or modify it under
8  * the terms of the GNU General Public License as published by the Free Software
9  * Foundation; either version 2 of the License, or (at your option) any later
10  * version.
11  *
12  *
13  * This driver registers the Technologic Systems TS-5500 Single Board Computer
14  * (SBC) and its devices, and exposes information to userspace such as jumpers'
15  * state or available options. For further information about sysfs entries, see
16  * Documentation/ABI/testing/sysfs-platform-ts5500.
17  *
18  * This code may be extended to support similar x86-based platforms.
19  * Actually, the TS-5500 and TS-5400 are supported.
20  */
21 
22 #include <linux/delay.h>
23 #include <linux/io.h>
24 #include <linux/kernel.h>
25 #include <linux/leds.h>
26 #include <linux/init.h>
27 #include <linux/platform_data/gpio-ts5500.h>
28 #include <linux/platform_data/max197.h>
29 #include <linux/platform_device.h>
30 #include <linux/slab.h>
31 
32 /* Product code register */
33 #define TS5500_PRODUCT_CODE_ADDR	0x74
34 #define TS5500_PRODUCT_CODE		0x60	/* TS-5500 product code */
35 #define TS5400_PRODUCT_CODE		0x40	/* TS-5400 product code */
36 
37 /* SRAM/RS-485/ADC options, and RS-485 RTS/Automatic RS-485 flags register */
38 #define TS5500_SRAM_RS485_ADC_ADDR	0x75
39 #define TS5500_SRAM			BIT(0)	/* SRAM option */
40 #define TS5500_RS485			BIT(1)	/* RS-485 option */
41 #define TS5500_ADC			BIT(2)	/* A/D converter option */
42 #define TS5500_RS485_RTS		BIT(6)	/* RTS for RS-485 */
43 #define TS5500_RS485_AUTO		BIT(7)	/* Automatic RS-485 */
44 
45 /* External Reset/Industrial Temperature Range options register */
46 #define TS5500_ERESET_ITR_ADDR		0x76
47 #define TS5500_ERESET			BIT(0)	/* External Reset option */
48 #define TS5500_ITR			BIT(1)	/* Indust. Temp. Range option */
49 
50 /* LED/Jumpers register */
51 #define TS5500_LED_JP_ADDR		0x77
52 #define TS5500_LED			BIT(0)	/* LED flag */
53 #define TS5500_JP1			BIT(1)	/* Automatic CMOS */
54 #define TS5500_JP2			BIT(2)	/* Enable Serial Console */
55 #define TS5500_JP3			BIT(3)	/* Write Enable Drive A */
56 #define TS5500_JP4			BIT(4)	/* Fast Console (115K baud) */
57 #define TS5500_JP5			BIT(5)	/* User Jumper */
58 #define TS5500_JP6			BIT(6)	/* Console on COM1 (req. JP2) */
59 #define TS5500_JP7			BIT(7)	/* Undocumented (Unused) */
60 
61 /* A/D Converter registers */
62 #define TS5500_ADC_CONV_BUSY_ADDR	0x195	/* Conversion state register */
63 #define TS5500_ADC_CONV_BUSY		BIT(0)
64 #define TS5500_ADC_CONV_INIT_LSB_ADDR	0x196	/* Start conv. / LSB register */
65 #define TS5500_ADC_CONV_MSB_ADDR	0x197	/* MSB register */
66 #define TS5500_ADC_CONV_DELAY		12	/* usec */
67 
68 /**
69  * struct ts5500_sbc - TS-5500 board description
70  * @name:	Board model name.
71  * @id:		Board product ID.
72  * @sram:	Flag for SRAM option.
73  * @rs485:	Flag for RS-485 option.
74  * @adc:	Flag for Analog/Digital converter option.
75  * @ereset:	Flag for External Reset option.
76  * @itr:	Flag for Industrial Temperature Range option.
77  * @jumpers:	Bitfield for jumpers' state.
78  */
79 struct ts5500_sbc {
80 	const char *name;
81 	int	id;
82 	bool	sram;
83 	bool	rs485;
84 	bool	adc;
85 	bool	ereset;
86 	bool	itr;
87 	u8	jumpers;
88 };
89 
90 /* Board signatures in BIOS shadow RAM */
91 static const struct {
92 	const char * const string;
93 	const ssize_t offset;
94 } ts5500_signatures[] __initconst = {
95 	{ "TS-5x00 AMD Elan", 0xb14 },
96 };
97 
98 static int __init ts5500_check_signature(void)
99 {
100 	void __iomem *bios;
101 	int i, ret = -ENODEV;
102 
103 	bios = ioremap(0xf0000, 0x10000);
104 	if (!bios)
105 		return -ENOMEM;
106 
107 	for (i = 0; i < ARRAY_SIZE(ts5500_signatures); i++) {
108 		if (check_signature(bios + ts5500_signatures[i].offset,
109 				    ts5500_signatures[i].string,
110 				    strlen(ts5500_signatures[i].string))) {
111 			ret = 0;
112 			break;
113 		}
114 	}
115 
116 	iounmap(bios);
117 	return ret;
118 }
119 
120 static int __init ts5500_detect_config(struct ts5500_sbc *sbc)
121 {
122 	u8 tmp;
123 	int ret = 0;
124 
125 	if (!request_region(TS5500_PRODUCT_CODE_ADDR, 4, "ts5500"))
126 		return -EBUSY;
127 
128 	sbc->id = inb(TS5500_PRODUCT_CODE_ADDR);
129 	if (sbc->id == TS5500_PRODUCT_CODE) {
130 		sbc->name = "TS-5500";
131 	} else if (sbc->id == TS5400_PRODUCT_CODE) {
132 		sbc->name = "TS-5400";
133 	} else {
134 		pr_err("ts5500: unknown product code 0x%x\n", sbc->id);
135 		ret = -ENODEV;
136 		goto cleanup;
137 	}
138 
139 	tmp = inb(TS5500_SRAM_RS485_ADC_ADDR);
140 	sbc->sram = tmp & TS5500_SRAM;
141 	sbc->rs485 = tmp & TS5500_RS485;
142 	sbc->adc = tmp & TS5500_ADC;
143 
144 	tmp = inb(TS5500_ERESET_ITR_ADDR);
145 	sbc->ereset = tmp & TS5500_ERESET;
146 	sbc->itr = tmp & TS5500_ITR;
147 
148 	tmp = inb(TS5500_LED_JP_ADDR);
149 	sbc->jumpers = tmp & ~TS5500_LED;
150 
151 cleanup:
152 	release_region(TS5500_PRODUCT_CODE_ADDR, 4);
153 	return ret;
154 }
155 
156 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
157 		char *buf)
158 {
159 	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
160 
161 	return sprintf(buf, "%s\n", sbc->name);
162 }
163 static DEVICE_ATTR_RO(name);
164 
165 static ssize_t id_show(struct device *dev, struct device_attribute *attr,
166 		char *buf)
167 {
168 	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
169 
170 	return sprintf(buf, "0x%.2x\n", sbc->id);
171 }
172 static DEVICE_ATTR_RO(id);
173 
174 static ssize_t jumpers_show(struct device *dev, struct device_attribute *attr,
175 		char *buf)
176 {
177 	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
178 
179 	return sprintf(buf, "0x%.2x\n", sbc->jumpers >> 1);
180 }
181 static DEVICE_ATTR_RO(jumpers);
182 
183 #define TS5500_ATTR_BOOL(_field)					\
184 	static ssize_t _field##_show(struct device *dev,		\
185 			struct device_attribute *attr, char *buf)	\
186 	{								\
187 		struct ts5500_sbc *sbc = dev_get_drvdata(dev);		\
188 									\
189 		return sprintf(buf, "%d\n", sbc->_field);		\
190 	}								\
191 	static DEVICE_ATTR_RO(_field)
192 
193 TS5500_ATTR_BOOL(sram);
194 TS5500_ATTR_BOOL(rs485);
195 TS5500_ATTR_BOOL(adc);
196 TS5500_ATTR_BOOL(ereset);
197 TS5500_ATTR_BOOL(itr);
198 
199 static struct attribute *ts5500_attributes[] = {
200 	&dev_attr_id.attr,
201 	&dev_attr_name.attr,
202 	&dev_attr_jumpers.attr,
203 	&dev_attr_sram.attr,
204 	&dev_attr_rs485.attr,
205 	&dev_attr_adc.attr,
206 	&dev_attr_ereset.attr,
207 	&dev_attr_itr.attr,
208 	NULL
209 };
210 
211 static const struct attribute_group ts5500_attr_group = {
212 	.attrs = ts5500_attributes,
213 };
214 
215 static struct resource ts5500_dio1_resource[] = {
216 	DEFINE_RES_IRQ_NAMED(7, "DIO1 interrupt"),
217 };
218 
219 static struct platform_device ts5500_dio1_pdev = {
220 	.name = "ts5500-dio1",
221 	.id = -1,
222 	.resource = ts5500_dio1_resource,
223 	.num_resources = 1,
224 };
225 
226 static struct resource ts5500_dio2_resource[] = {
227 	DEFINE_RES_IRQ_NAMED(6, "DIO2 interrupt"),
228 };
229 
230 static struct platform_device ts5500_dio2_pdev = {
231 	.name = "ts5500-dio2",
232 	.id = -1,
233 	.resource = ts5500_dio2_resource,
234 	.num_resources = 1,
235 };
236 
237 static void ts5500_led_set(struct led_classdev *led_cdev,
238 			   enum led_brightness brightness)
239 {
240 	outb(!!brightness, TS5500_LED_JP_ADDR);
241 }
242 
243 static enum led_brightness ts5500_led_get(struct led_classdev *led_cdev)
244 {
245 	return (inb(TS5500_LED_JP_ADDR) & TS5500_LED) ? LED_FULL : LED_OFF;
246 }
247 
248 static struct led_classdev ts5500_led_cdev = {
249 	.name = "ts5500:green:",
250 	.brightness_set = ts5500_led_set,
251 	.brightness_get = ts5500_led_get,
252 };
253 
254 static int ts5500_adc_convert(u8 ctrl)
255 {
256 	u8 lsb, msb;
257 
258 	/* Start conversion (ensure the 3 MSB are set to 0) */
259 	outb(ctrl & 0x1f, TS5500_ADC_CONV_INIT_LSB_ADDR);
260 
261 	/*
262 	 * The platform has CPLD logic driving the A/D converter.
263 	 * The conversion must complete within 11 microseconds,
264 	 * otherwise we have to re-initiate a conversion.
265 	 */
266 	udelay(TS5500_ADC_CONV_DELAY);
267 	if (inb(TS5500_ADC_CONV_BUSY_ADDR) & TS5500_ADC_CONV_BUSY)
268 		return -EBUSY;
269 
270 	/* Read the raw data */
271 	lsb = inb(TS5500_ADC_CONV_INIT_LSB_ADDR);
272 	msb = inb(TS5500_ADC_CONV_MSB_ADDR);
273 
274 	return (msb << 8) | lsb;
275 }
276 
277 static struct max197_platform_data ts5500_adc_pdata = {
278 	.convert = ts5500_adc_convert,
279 };
280 
281 static struct platform_device ts5500_adc_pdev = {
282 	.name = "max197",
283 	.id = -1,
284 	.dev = {
285 		.platform_data = &ts5500_adc_pdata,
286 	},
287 };
288 
289 static int __init ts5500_init(void)
290 {
291 	struct platform_device *pdev;
292 	struct ts5500_sbc *sbc;
293 	int err;
294 
295 	/*
296 	 * There is no DMI available or PCI bridge subvendor info,
297 	 * only the BIOS provides a 16-bit identification call.
298 	 * It is safer to find a signature in the BIOS shadow RAM.
299 	 */
300 	err = ts5500_check_signature();
301 	if (err)
302 		return err;
303 
304 	pdev = platform_device_register_simple("ts5500", -1, NULL, 0);
305 	if (IS_ERR(pdev))
306 		return PTR_ERR(pdev);
307 
308 	sbc = devm_kzalloc(&pdev->dev, sizeof(struct ts5500_sbc), GFP_KERNEL);
309 	if (!sbc) {
310 		err = -ENOMEM;
311 		goto error;
312 	}
313 
314 	err = ts5500_detect_config(sbc);
315 	if (err)
316 		goto error;
317 
318 	platform_set_drvdata(pdev, sbc);
319 
320 	err = sysfs_create_group(&pdev->dev.kobj, &ts5500_attr_group);
321 	if (err)
322 		goto error;
323 
324 	if (sbc->id == TS5500_PRODUCT_CODE) {
325 		ts5500_dio1_pdev.dev.parent = &pdev->dev;
326 		if (platform_device_register(&ts5500_dio1_pdev))
327 			dev_warn(&pdev->dev, "DIO1 block registration failed\n");
328 		ts5500_dio2_pdev.dev.parent = &pdev->dev;
329 		if (platform_device_register(&ts5500_dio2_pdev))
330 			dev_warn(&pdev->dev, "DIO2 block registration failed\n");
331 	}
332 
333 	if (led_classdev_register(&pdev->dev, &ts5500_led_cdev))
334 		dev_warn(&pdev->dev, "LED registration failed\n");
335 
336 	if (sbc->adc) {
337 		ts5500_adc_pdev.dev.parent = &pdev->dev;
338 		if (platform_device_register(&ts5500_adc_pdev))
339 			dev_warn(&pdev->dev, "ADC registration failed\n");
340 	}
341 
342 	return 0;
343 error:
344 	platform_device_unregister(pdev);
345 	return err;
346 }
347 device_initcall(ts5500_init);
348