tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1/* drivers/rtc/rtc-v3020.c
2 *
3 * Copyright (C) 2006 8D Technologies inc.
4 * Copyright (C) 2004 Compulab Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Driver for the V3020 RTC
11 *
12 * Changelog:
13 *
14 * 10-May-2006: Raphael Assenat <raph@8d.com>
15 * - Converted to platform driver
16 * - Use the generic rtc class
17 *
18 * ??-???-2004: Someone at Compulab
19 * - Initial driver creation.
20 *
21 */
22#include <linux/platform_device.h>
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/rtc.h>
26#include <linux/types.h>
27#include <linux/bcd.h>
28#include <linux/rtc-v3020.h>
29#include <linux/delay.h>
30#include <linux/gpio.h>
31
32#include <linux/io.h>
33
34#undef DEBUG
35
36struct v3020;
37
38struct v3020_chip_ops {
39 int (*map_io)(struct v3020 *chip, struct platform_device *pdev,
40 struct v3020_platform_data *pdata);
41 void (*unmap_io)(struct v3020 *chip);
42 unsigned char (*read_bit)(struct v3020 *chip);
43 void (*write_bit)(struct v3020 *chip, unsigned char bit);
44};
45
46#define V3020_CS 0
47#define V3020_WR 1
48#define V3020_RD 2
49#define V3020_IO 3
50
51struct v3020_gpio {
52 const char *name;
53 unsigned int gpio;
54};
55
56struct v3020 {
57 /* MMIO access */
58 void __iomem *ioaddress;
59 int leftshift;
60
61 /* GPIO access */
62 struct v3020_gpio *gpio;
63
64 struct v3020_chip_ops *ops;
65
66 struct rtc_device *rtc;
67};
68
69
70static int v3020_mmio_map(struct v3020 *chip, struct platform_device *pdev,
71 struct v3020_platform_data *pdata)
72{
73 if (pdev->num_resources != 1)
74 return -EBUSY;
75
76 if (pdev->resource[0].flags != IORESOURCE_MEM)
77 return -EBUSY;
78
79 chip->leftshift = pdata->leftshift;
80 chip->ioaddress = ioremap(pdev->resource[0].start, 1);
81 if (chip->ioaddress == NULL)
82 return -EBUSY;
83
84 return 0;
85}
86
87static void v3020_mmio_unmap(struct v3020 *chip)
88{
89 iounmap(chip->ioaddress);
90}
91
92static void v3020_mmio_write_bit(struct v3020 *chip, unsigned char bit)
93{
94 writel(bit << chip->leftshift, chip->ioaddress);
95}
96
97static unsigned char v3020_mmio_read_bit(struct v3020 *chip)
98{
99 return readl(chip->ioaddress) & (1 << chip->leftshift);
100}
101
102static struct v3020_chip_ops v3020_mmio_ops = {
103 .map_io = v3020_mmio_map,
104 .unmap_io = v3020_mmio_unmap,
105 .read_bit = v3020_mmio_read_bit,
106 .write_bit = v3020_mmio_write_bit,
107};
108
109static struct v3020_gpio v3020_gpio[] = {
110 { "RTC CS", 0 },
111 { "RTC WR", 0 },
112 { "RTC RD", 0 },
113 { "RTC IO", 0 },
114};
115
116static int v3020_gpio_map(struct v3020 *chip, struct platform_device *pdev,
117 struct v3020_platform_data *pdata)
118{
119 int i, err;
120
121 v3020_gpio[V3020_CS].gpio = pdata->gpio_cs;
122 v3020_gpio[V3020_WR].gpio = pdata->gpio_wr;
123 v3020_gpio[V3020_RD].gpio = pdata->gpio_rd;
124 v3020_gpio[V3020_IO].gpio = pdata->gpio_io;
125
126 for (i = 0; i < ARRAY_SIZE(v3020_gpio); i++) {
127 err = gpio_request(v3020_gpio[i].gpio, v3020_gpio[i].name);
128 if (err)
129 goto err_request;
130
131 gpio_direction_output(v3020_gpio[i].gpio, 1);
132 }
133
134 chip->gpio = v3020_gpio;
135
136 return 0;
137
138err_request:
139 while (--i >= 0)
140 gpio_free(v3020_gpio[i].gpio);
141
142 return err;
143}
144
145static void v3020_gpio_unmap(struct v3020 *chip)
146{
147 int i;
148
149 for (i = 0; i < ARRAY_SIZE(v3020_gpio); i++)
150 gpio_free(v3020_gpio[i].gpio);
151}
152
153static void v3020_gpio_write_bit(struct v3020 *chip, unsigned char bit)
154{
155 gpio_direction_output(chip->gpio[V3020_IO].gpio, bit);
156 gpio_set_value(chip->gpio[V3020_CS].gpio, 0);
157 gpio_set_value(chip->gpio[V3020_WR].gpio, 0);
158 udelay(1);
159 gpio_set_value(chip->gpio[V3020_WR].gpio, 1);
160 gpio_set_value(chip->gpio[V3020_CS].gpio, 1);
161}
162
163static unsigned char v3020_gpio_read_bit(struct v3020 *chip)
164{
165 int bit;
166
167 gpio_direction_input(chip->gpio[V3020_IO].gpio);
168 gpio_set_value(chip->gpio[V3020_CS].gpio, 0);
169 gpio_set_value(chip->gpio[V3020_RD].gpio, 0);
170 udelay(1);
171 bit = !!gpio_get_value(chip->gpio[V3020_IO].gpio);
172 udelay(1);
173 gpio_set_value(chip->gpio[V3020_RD].gpio, 1);
174 gpio_set_value(chip->gpio[V3020_CS].gpio, 1);
175
176 return bit;
177}
178
179static struct v3020_chip_ops v3020_gpio_ops = {
180 .map_io = v3020_gpio_map,
181 .unmap_io = v3020_gpio_unmap,
182 .read_bit = v3020_gpio_read_bit,
183 .write_bit = v3020_gpio_write_bit,
184};
185
186static void v3020_set_reg(struct v3020 *chip, unsigned char address,
187 unsigned char data)
188{
189 int i;
190 unsigned char tmp;
191
192 tmp = address;
193 for (i = 0; i < 4; i++) {
194 chip->ops->write_bit(chip, (tmp & 1));
195 tmp >>= 1;
196 udelay(1);
197 }
198
199 /* Commands dont have data */
200 if (!V3020_IS_COMMAND(address)) {
201 for (i = 0; i < 8; i++) {
202 chip->ops->write_bit(chip, (data & 1));
203 data >>= 1;
204 udelay(1);
205 }
206 }
207}
208
209static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address)
210{
211 unsigned int data = 0;
212 int i;
213
214 for (i = 0; i < 4; i++) {
215 chip->ops->write_bit(chip, (address & 1));
216 address >>= 1;
217 udelay(1);
218 }
219
220 for (i = 0; i < 8; i++) {
221 data >>= 1;
222 if (chip->ops->read_bit(chip))
223 data |= 0x80;
224 udelay(1);
225 }
226
227 return data;
228}
229
230static int v3020_read_time(struct device *dev, struct rtc_time *dt)
231{
232 struct v3020 *chip = dev_get_drvdata(dev);
233 int tmp;
234
235 /* Copy the current time to ram... */
236 v3020_set_reg(chip, V3020_CMD_CLOCK2RAM, 0);
237
238 /* ...and then read constant values. */
239 tmp = v3020_get_reg(chip, V3020_SECONDS);
240 dt->tm_sec = bcd2bin(tmp);
241 tmp = v3020_get_reg(chip, V3020_MINUTES);
242 dt->tm_min = bcd2bin(tmp);
243 tmp = v3020_get_reg(chip, V3020_HOURS);
244 dt->tm_hour = bcd2bin(tmp);
245 tmp = v3020_get_reg(chip, V3020_MONTH_DAY);
246 dt->tm_mday = bcd2bin(tmp);
247 tmp = v3020_get_reg(chip, V3020_MONTH);
248 dt->tm_mon = bcd2bin(tmp) - 1;
249 tmp = v3020_get_reg(chip, V3020_WEEK_DAY);
250 dt->tm_wday = bcd2bin(tmp);
251 tmp = v3020_get_reg(chip, V3020_YEAR);
252 dt->tm_year = bcd2bin(tmp)+100;
253
254 dev_dbg(dev, "\n%s : Read RTC values\n", __func__);
255 dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
256 dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
257 dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
258 dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
259 dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
260 dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
261 dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
262
263 return 0;
264}
265
266
267static int v3020_set_time(struct device *dev, struct rtc_time *dt)
268{
269 struct v3020 *chip = dev_get_drvdata(dev);
270
271 dev_dbg(dev, "\n%s : Setting RTC values\n", __func__);
272 dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
273 dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
274 dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
275 dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
276 dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
277 dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
278
279 /* Write all the values to ram... */
280 v3020_set_reg(chip, V3020_SECONDS, bin2bcd(dt->tm_sec));
281 v3020_set_reg(chip, V3020_MINUTES, bin2bcd(dt->tm_min));
282 v3020_set_reg(chip, V3020_HOURS, bin2bcd(dt->tm_hour));
283 v3020_set_reg(chip, V3020_MONTH_DAY, bin2bcd(dt->tm_mday));
284 v3020_set_reg(chip, V3020_MONTH, bin2bcd(dt->tm_mon + 1));
285 v3020_set_reg(chip, V3020_WEEK_DAY, bin2bcd(dt->tm_wday));
286 v3020_set_reg(chip, V3020_YEAR, bin2bcd(dt->tm_year % 100));
287
288 /* ...and set the clock. */
289 v3020_set_reg(chip, V3020_CMD_RAM2CLOCK, 0);
290
291 /* Compulab used this delay here. I dont know why,
292 * the datasheet does not specify a delay. */
293 /*mdelay(5);*/
294
295 return 0;
296}
297
298static const struct rtc_class_ops v3020_rtc_ops = {
299 .read_time = v3020_read_time,
300 .set_time = v3020_set_time,
301};
302
303static int rtc_probe(struct platform_device *pdev)
304{
305 struct v3020_platform_data *pdata = pdev->dev.platform_data;
306 struct v3020 *chip;
307 struct rtc_device *rtc;
308 int retval = -EBUSY;
309 int i;
310 int temp;
311
312 chip = kzalloc(sizeof *chip, GFP_KERNEL);
313 if (!chip)
314 return -ENOMEM;
315
316 if (pdata->use_gpio)
317 chip->ops = &v3020_gpio_ops;
318 else
319 chip->ops = &v3020_mmio_ops;
320
321 retval = chip->ops->map_io(chip, pdev, pdata);
322 if (retval)
323 goto err_chip;
324
325 /* Make sure the v3020 expects a communication cycle
326 * by reading 8 times */
327 for (i = 0; i < 8; i++)
328 temp = chip->ops->read_bit(chip);
329
330 /* Test chip by doing a write/read sequence
331 * to the chip ram */
332 v3020_set_reg(chip, V3020_SECONDS, 0x33);
333 if (v3020_get_reg(chip, V3020_SECONDS) != 0x33) {
334 retval = -ENODEV;
335 goto err_io;
336 }
337
338 /* Make sure frequency measurment mode, test modes, and lock
339 * are all disabled */
340 v3020_set_reg(chip, V3020_STATUS_0, 0x0);
341
342 if (pdata->use_gpio)
343 dev_info(&pdev->dev, "Chip available at GPIOs "
344 "%d, %d, %d, %d\n",
345 chip->gpio[V3020_CS].gpio, chip->gpio[V3020_WR].gpio,
346 chip->gpio[V3020_RD].gpio, chip->gpio[V3020_IO].gpio);
347 else
348 dev_info(&pdev->dev, "Chip available at "
349 "physical address 0x%llx,"
350 "data connected to D%d\n",
351 (unsigned long long)pdev->resource[0].start,
352 chip->leftshift);
353
354 platform_set_drvdata(pdev, chip);
355
356 rtc = rtc_device_register("v3020",
357 &pdev->dev, &v3020_rtc_ops, THIS_MODULE);
358 if (IS_ERR(rtc)) {
359 retval = PTR_ERR(rtc);
360 goto err_io;
361 }
362 chip->rtc = rtc;
363
364 return 0;
365
366err_io:
367 chip->ops->unmap_io(chip);
368err_chip:
369 kfree(chip);
370
371 return retval;
372}
373
374static int rtc_remove(struct platform_device *dev)
375{
376 struct v3020 *chip = platform_get_drvdata(dev);
377 struct rtc_device *rtc = chip->rtc;
378
379 if (rtc)
380 rtc_device_unregister(rtc);
381
382 chip->ops->unmap_io(chip);
383 kfree(chip);
384
385 return 0;
386}
387
388static struct platform_driver rtc_device_driver = {
389 .probe = rtc_probe,
390 .remove = rtc_remove,
391 .driver = {
392 .name = "v3020",
393 .owner = THIS_MODULE,
394 },
395};
396
397static __init int v3020_init(void)
398{
399 return platform_driver_register(&rtc_device_driver);
400}
401
402static __exit void v3020_exit(void)
403{
404 platform_driver_unregister(&rtc_device_driver);
405}
406
407module_init(v3020_init);
408module_exit(v3020_exit);
409
410MODULE_DESCRIPTION("V3020 RTC");
411MODULE_AUTHOR("Raphael Assenat");
412MODULE_LICENSE("GPL");
413MODULE_ALIAS("platform:v3020");