xref: /openbmc/linux/arch/x86/platform/ts5500/ts5500.c (revision d2574c33)
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/max197.h>
28 #include <linux/platform_device.h>
29 #include <linux/slab.h>
30 
31 /* Product code register */
32 #define TS5500_PRODUCT_CODE_ADDR	0x74
33 #define TS5500_PRODUCT_CODE		0x60	/* TS-5500 product code */
34 #define TS5400_PRODUCT_CODE		0x40	/* TS-5400 product code */
35 
36 /* SRAM/RS-485/ADC options, and RS-485 RTS/Automatic RS-485 flags register */
37 #define TS5500_SRAM_RS485_ADC_ADDR	0x75
38 #define TS5500_SRAM			BIT(0)	/* SRAM option */
39 #define TS5500_RS485			BIT(1)	/* RS-485 option */
40 #define TS5500_ADC			BIT(2)	/* A/D converter option */
41 #define TS5500_RS485_RTS		BIT(6)	/* RTS for RS-485 */
42 #define TS5500_RS485_AUTO		BIT(7)	/* Automatic RS-485 */
43 
44 /* External Reset/Industrial Temperature Range options register */
45 #define TS5500_ERESET_ITR_ADDR		0x76
46 #define TS5500_ERESET			BIT(0)	/* External Reset option */
47 #define TS5500_ITR			BIT(1)	/* Indust. Temp. Range option */
48 
49 /* LED/Jumpers register */
50 #define TS5500_LED_JP_ADDR		0x77
51 #define TS5500_LED			BIT(0)	/* LED flag */
52 #define TS5500_JP1			BIT(1)	/* Automatic CMOS */
53 #define TS5500_JP2			BIT(2)	/* Enable Serial Console */
54 #define TS5500_JP3			BIT(3)	/* Write Enable Drive A */
55 #define TS5500_JP4			BIT(4)	/* Fast Console (115K baud) */
56 #define TS5500_JP5			BIT(5)	/* User Jumper */
57 #define TS5500_JP6			BIT(6)	/* Console on COM1 (req. JP2) */
58 #define TS5500_JP7			BIT(7)	/* Undocumented (Unused) */
59 
60 /* A/D Converter registers */
61 #define TS5500_ADC_CONV_BUSY_ADDR	0x195	/* Conversion state register */
62 #define TS5500_ADC_CONV_BUSY		BIT(0)
63 #define TS5500_ADC_CONV_INIT_LSB_ADDR	0x196	/* Start conv. / LSB register */
64 #define TS5500_ADC_CONV_MSB_ADDR	0x197	/* MSB register */
65 #define TS5500_ADC_CONV_DELAY		12	/* usec */
66 
67 /**
68  * struct ts5500_sbc - TS-5500 board description
69  * @name:	Board model name.
70  * @id:		Board product ID.
71  * @sram:	Flag for SRAM option.
72  * @rs485:	Flag for RS-485 option.
73  * @adc:	Flag for Analog/Digital converter option.
74  * @ereset:	Flag for External Reset option.
75  * @itr:	Flag for Industrial Temperature Range option.
76  * @jumpers:	Bitfield for jumpers' state.
77  */
78 struct ts5500_sbc {
79 	const char *name;
80 	int	id;
81 	bool	sram;
82 	bool	rs485;
83 	bool	adc;
84 	bool	ereset;
85 	bool	itr;
86 	u8	jumpers;
87 };
88 
89 /* Board signatures in BIOS shadow RAM */
90 static const struct {
91 	const char * const string;
92 	const ssize_t offset;
93 } ts5500_signatures[] __initconst = {
94 	{ "TS-5x00 AMD Elan", 0xb14 },
95 };
96 
97 static int __init ts5500_check_signature(void)
98 {
99 	void __iomem *bios;
100 	int i, ret = -ENODEV;
101 
102 	bios = ioremap(0xf0000, 0x10000);
103 	if (!bios)
104 		return -ENOMEM;
105 
106 	for (i = 0; i < ARRAY_SIZE(ts5500_signatures); i++) {
107 		if (check_signature(bios + ts5500_signatures[i].offset,
108 				    ts5500_signatures[i].string,
109 				    strlen(ts5500_signatures[i].string))) {
110 			ret = 0;
111 			break;
112 		}
113 	}
114 
115 	iounmap(bios);
116 	return ret;
117 }
118 
119 static int __init ts5500_detect_config(struct ts5500_sbc *sbc)
120 {
121 	u8 tmp;
122 	int ret = 0;
123 
124 	if (!request_region(TS5500_PRODUCT_CODE_ADDR, 4, "ts5500"))
125 		return -EBUSY;
126 
127 	sbc->id = inb(TS5500_PRODUCT_CODE_ADDR);
128 	if (sbc->id == TS5500_PRODUCT_CODE) {
129 		sbc->name = "TS-5500";
130 	} else if (sbc->id == TS5400_PRODUCT_CODE) {
131 		sbc->name = "TS-5400";
132 	} else {
133 		pr_err("ts5500: unknown product code 0x%x\n", sbc->id);
134 		ret = -ENODEV;
135 		goto cleanup;
136 	}
137 
138 	tmp = inb(TS5500_SRAM_RS485_ADC_ADDR);
139 	sbc->sram = tmp & TS5500_SRAM;
140 	sbc->rs485 = tmp & TS5500_RS485;
141 	sbc->adc = tmp & TS5500_ADC;
142 
143 	tmp = inb(TS5500_ERESET_ITR_ADDR);
144 	sbc->ereset = tmp & TS5500_ERESET;
145 	sbc->itr = tmp & TS5500_ITR;
146 
147 	tmp = inb(TS5500_LED_JP_ADDR);
148 	sbc->jumpers = tmp & ~TS5500_LED;
149 
150 cleanup:
151 	release_region(TS5500_PRODUCT_CODE_ADDR, 4);
152 	return ret;
153 }
154 
155 static ssize_t name_show(struct device *dev, struct device_attribute *attr,
156 		char *buf)
157 {
158 	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
159 
160 	return sprintf(buf, "%s\n", sbc->name);
161 }
162 static DEVICE_ATTR_RO(name);
163 
164 static ssize_t id_show(struct device *dev, struct device_attribute *attr,
165 		char *buf)
166 {
167 	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
168 
169 	return sprintf(buf, "0x%.2x\n", sbc->id);
170 }
171 static DEVICE_ATTR_RO(id);
172 
173 static ssize_t jumpers_show(struct device *dev, struct device_attribute *attr,
174 		char *buf)
175 {
176 	struct ts5500_sbc *sbc = dev_get_drvdata(dev);
177 
178 	return sprintf(buf, "0x%.2x\n", sbc->jumpers >> 1);
179 }
180 static DEVICE_ATTR_RO(jumpers);
181 
182 #define TS5500_ATTR_BOOL(_field)					\
183 	static ssize_t _field##_show(struct device *dev,		\
184 			struct device_attribute *attr, char *buf)	\
185 	{								\
186 		struct ts5500_sbc *sbc = dev_get_drvdata(dev);		\
187 									\
188 		return sprintf(buf, "%d\n", sbc->_field);		\
189 	}								\
190 	static DEVICE_ATTR_RO(_field)
191 
192 TS5500_ATTR_BOOL(sram);
193 TS5500_ATTR_BOOL(rs485);
194 TS5500_ATTR_BOOL(adc);
195 TS5500_ATTR_BOOL(ereset);
196 TS5500_ATTR_BOOL(itr);
197 
198 static struct attribute *ts5500_attributes[] = {
199 	&dev_attr_id.attr,
200 	&dev_attr_name.attr,
201 	&dev_attr_jumpers.attr,
202 	&dev_attr_sram.attr,
203 	&dev_attr_rs485.attr,
204 	&dev_attr_adc.attr,
205 	&dev_attr_ereset.attr,
206 	&dev_attr_itr.attr,
207 	NULL
208 };
209 
210 static const struct attribute_group ts5500_attr_group = {
211 	.attrs = ts5500_attributes,
212 };
213 
214 static struct resource ts5500_dio1_resource[] = {
215 	DEFINE_RES_IRQ_NAMED(7, "DIO1 interrupt"),
216 };
217 
218 static struct platform_device ts5500_dio1_pdev = {
219 	.name = "ts5500-dio1",
220 	.id = -1,
221 	.resource = ts5500_dio1_resource,
222 	.num_resources = 1,
223 };
224 
225 static struct resource ts5500_dio2_resource[] = {
226 	DEFINE_RES_IRQ_NAMED(6, "DIO2 interrupt"),
227 };
228 
229 static struct platform_device ts5500_dio2_pdev = {
230 	.name = "ts5500-dio2",
231 	.id = -1,
232 	.resource = ts5500_dio2_resource,
233 	.num_resources = 1,
234 };
235 
236 static void ts5500_led_set(struct led_classdev *led_cdev,
237 			   enum led_brightness brightness)
238 {
239 	outb(!!brightness, TS5500_LED_JP_ADDR);
240 }
241 
242 static enum led_brightness ts5500_led_get(struct led_classdev *led_cdev)
243 {
244 	return (inb(TS5500_LED_JP_ADDR) & TS5500_LED) ? LED_FULL : LED_OFF;
245 }
246 
247 static struct led_classdev ts5500_led_cdev = {
248 	.name = "ts5500:green:",
249 	.brightness_set = ts5500_led_set,
250 	.brightness_get = ts5500_led_get,
251 };
252 
253 static int ts5500_adc_convert(u8 ctrl)
254 {
255 	u8 lsb, msb;
256 
257 	/* Start conversion (ensure the 3 MSB are set to 0) */
258 	outb(ctrl & 0x1f, TS5500_ADC_CONV_INIT_LSB_ADDR);
259 
260 	/*
261 	 * The platform has CPLD logic driving the A/D converter.
262 	 * The conversion must complete within 11 microseconds,
263 	 * otherwise we have to re-initiate a conversion.
264 	 */
265 	udelay(TS5500_ADC_CONV_DELAY);
266 	if (inb(TS5500_ADC_CONV_BUSY_ADDR) & TS5500_ADC_CONV_BUSY)
267 		return -EBUSY;
268 
269 	/* Read the raw data */
270 	lsb = inb(TS5500_ADC_CONV_INIT_LSB_ADDR);
271 	msb = inb(TS5500_ADC_CONV_MSB_ADDR);
272 
273 	return (msb << 8) | lsb;
274 }
275 
276 static struct max197_platform_data ts5500_adc_pdata = {
277 	.convert = ts5500_adc_convert,
278 };
279 
280 static struct platform_device ts5500_adc_pdev = {
281 	.name = "max197",
282 	.id = -1,
283 	.dev = {
284 		.platform_data = &ts5500_adc_pdata,
285 	},
286 };
287 
288 static int __init ts5500_init(void)
289 {
290 	struct platform_device *pdev;
291 	struct ts5500_sbc *sbc;
292 	int err;
293 
294 	/*
295 	 * There is no DMI available or PCI bridge subvendor info,
296 	 * only the BIOS provides a 16-bit identification call.
297 	 * It is safer to find a signature in the BIOS shadow RAM.
298 	 */
299 	err = ts5500_check_signature();
300 	if (err)
301 		return err;
302 
303 	pdev = platform_device_register_simple("ts5500", -1, NULL, 0);
304 	if (IS_ERR(pdev))
305 		return PTR_ERR(pdev);
306 
307 	sbc = devm_kzalloc(&pdev->dev, sizeof(struct ts5500_sbc), GFP_KERNEL);
308 	if (!sbc) {
309 		err = -ENOMEM;
310 		goto error;
311 	}
312 
313 	err = ts5500_detect_config(sbc);
314 	if (err)
315 		goto error;
316 
317 	platform_set_drvdata(pdev, sbc);
318 
319 	err = sysfs_create_group(&pdev->dev.kobj, &ts5500_attr_group);
320 	if (err)
321 		goto error;
322 
323 	if (sbc->id == TS5500_PRODUCT_CODE) {
324 		ts5500_dio1_pdev.dev.parent = &pdev->dev;
325 		if (platform_device_register(&ts5500_dio1_pdev))
326 			dev_warn(&pdev->dev, "DIO1 block registration failed\n");
327 		ts5500_dio2_pdev.dev.parent = &pdev->dev;
328 		if (platform_device_register(&ts5500_dio2_pdev))
329 			dev_warn(&pdev->dev, "DIO2 block registration failed\n");
330 	}
331 
332 	if (led_classdev_register(&pdev->dev, &ts5500_led_cdev))
333 		dev_warn(&pdev->dev, "LED registration failed\n");
334 
335 	if (sbc->adc) {
336 		ts5500_adc_pdev.dev.parent = &pdev->dev;
337 		if (platform_device_register(&ts5500_adc_pdev))
338 			dev_warn(&pdev->dev, "ADC registration failed\n");
339 	}
340 
341 	return 0;
342 error:
343 	platform_device_unregister(pdev);
344 	return err;
345 }
346 device_initcall(ts5500_init);
347