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Raphael Assenat362600f2006-06-25 05:48:24 -07001/* 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>
Mike Rapoportf3d79b22007-09-11 15:23:45 -070029#include <linux/delay.h>
Mike Rapoport96615842009-04-02 16:57:01 -070030#include <linux/gpio.h>
Raphael Assenat362600f2006-06-25 05:48:24 -070031
Mike Rapoportc08cf9d2009-03-31 15:24:59 -070032#include <linux/io.h>
Raphael Assenat362600f2006-06-25 05:48:24 -070033
34#undef DEBUG
35
Mike Rapoport96615842009-04-02 16:57:01 -070036struct 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
Raphael Assenat362600f2006-06-25 05:48:24 -070056struct v3020 {
Mike Rapoport96615842009-04-02 16:57:01 -070057 /* MMIO access */
Raphael Assenat362600f2006-06-25 05:48:24 -070058 void __iomem *ioaddress;
59 int leftshift;
Mike Rapoport96615842009-04-02 16:57:01 -070060
61 /* GPIO access */
62 struct v3020_gpio *gpio;
63
64 struct v3020_chip_ops *ops;
65
Raphael Assenat362600f2006-06-25 05:48:24 -070066 struct rtc_device *rtc;
67};
68
Mike Rapoport96615842009-04-02 16:57:01 -070069
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{
Scott Valentinebcb3a162009-11-11 14:26:49 -080099 return !!(readl(chip->ioaddress) & (1 << chip->leftshift));
Mike Rapoport96615842009-04-02 16:57:01 -0700100}
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
Raphael Assenat362600f2006-06-25 05:48:24 -0700186static 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++) {
Mike Rapoport96615842009-04-02 16:57:01 -0700194 chip->ops->write_bit(chip, (tmp & 1));
Raphael Assenat362600f2006-06-25 05:48:24 -0700195 tmp >>= 1;
Mike Rapoportf3d79b22007-09-11 15:23:45 -0700196 udelay(1);
Raphael Assenat362600f2006-06-25 05:48:24 -0700197 }
198
199 /* Commands dont have data */
200 if (!V3020_IS_COMMAND(address)) {
201 for (i = 0; i < 8; i++) {
Mike Rapoport96615842009-04-02 16:57:01 -0700202 chip->ops->write_bit(chip, (data & 1));
Raphael Assenat362600f2006-06-25 05:48:24 -0700203 data >>= 1;
Mike Rapoportf3d79b22007-09-11 15:23:45 -0700204 udelay(1);
Raphael Assenat362600f2006-06-25 05:48:24 -0700205 }
206 }
207}
208
209static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address)
210{
Mike Rapoportc08cf9d2009-03-31 15:24:59 -0700211 unsigned int data = 0;
Raphael Assenat362600f2006-06-25 05:48:24 -0700212 int i;
213
214 for (i = 0; i < 4; i++) {
Mike Rapoport96615842009-04-02 16:57:01 -0700215 chip->ops->write_bit(chip, (address & 1));
Raphael Assenat362600f2006-06-25 05:48:24 -0700216 address >>= 1;
Mike Rapoportf3d79b22007-09-11 15:23:45 -0700217 udelay(1);
Raphael Assenat362600f2006-06-25 05:48:24 -0700218 }
219
220 for (i = 0; i < 8; i++) {
221 data >>= 1;
Mike Rapoport96615842009-04-02 16:57:01 -0700222 if (chip->ops->read_bit(chip))
Raphael Assenat362600f2006-06-25 05:48:24 -0700223 data |= 0x80;
Mike Rapoportf3d79b22007-09-11 15:23:45 -0700224 udelay(1);
Raphael Assenat362600f2006-06-25 05:48:24 -0700225 }
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);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700240 dt->tm_sec = bcd2bin(tmp);
Raphael Assenat362600f2006-06-25 05:48:24 -0700241 tmp = v3020_get_reg(chip, V3020_MINUTES);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700242 dt->tm_min = bcd2bin(tmp);
Raphael Assenat362600f2006-06-25 05:48:24 -0700243 tmp = v3020_get_reg(chip, V3020_HOURS);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700244 dt->tm_hour = bcd2bin(tmp);
Raphael Assenat362600f2006-06-25 05:48:24 -0700245 tmp = v3020_get_reg(chip, V3020_MONTH_DAY);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700246 dt->tm_mday = bcd2bin(tmp);
Raphael Assenat362600f2006-06-25 05:48:24 -0700247 tmp = v3020_get_reg(chip, V3020_MONTH);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700248 dt->tm_mon = bcd2bin(tmp) - 1;
Raphael Assenat362600f2006-06-25 05:48:24 -0700249 tmp = v3020_get_reg(chip, V3020_WEEK_DAY);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700250 dt->tm_wday = bcd2bin(tmp);
Raphael Assenat362600f2006-06-25 05:48:24 -0700251 tmp = v3020_get_reg(chip, V3020_YEAR);
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700252 dt->tm_year = bcd2bin(tmp)+100;
Raphael Assenat362600f2006-06-25 05:48:24 -0700253
Mike Rapoportc08cf9d2009-03-31 15:24:59 -0700254 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);
Raphael Assenat362600f2006-06-25 05:48:24 -0700262
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
Mike Rapoportc08cf9d2009-03-31 15:24:59 -0700271 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);
Raphael Assenat362600f2006-06-25 05:48:24 -0700278
279 /* Write all the values to ram... */
Adrian Bunkfe20ba72008-10-18 20:28:41 -0700280 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));
Raphael Assenat362600f2006-06-25 05:48:24 -0700287
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
David Brownellff8371a2006-09-30 23:28:17 -0700298static const struct rtc_class_ops v3020_rtc_ops = {
Raphael Assenat362600f2006-06-25 05:48:24 -0700299 .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;
Raphael Assenat362600f2006-06-25 05:48:24 -0700307 int retval = -EBUSY;
308 int i;
309 int temp;
310
Raphael Assenat362600f2006-06-25 05:48:24 -0700311 chip = kzalloc(sizeof *chip, GFP_KERNEL);
312 if (!chip)
313 return -ENOMEM;
314
Mike Rapoport96615842009-04-02 16:57:01 -0700315 if (pdata->use_gpio)
316 chip->ops = &v3020_gpio_ops;
317 else
318 chip->ops = &v3020_mmio_ops;
319
320 retval = chip->ops->map_io(chip, pdev, pdata);
321 if (retval)
Raphael Assenat362600f2006-06-25 05:48:24 -0700322 goto err_chip;
323
324 /* Make sure the v3020 expects a communication cycle
325 * by reading 8 times */
326 for (i = 0; i < 8; i++)
Mike Rapoport96615842009-04-02 16:57:01 -0700327 temp = chip->ops->read_bit(chip);
Raphael Assenat362600f2006-06-25 05:48:24 -0700328
329 /* Test chip by doing a write/read sequence
330 * to the chip ram */
331 v3020_set_reg(chip, V3020_SECONDS, 0x33);
Mike Rapoportc08cf9d2009-03-31 15:24:59 -0700332 if (v3020_get_reg(chip, V3020_SECONDS) != 0x33) {
Raphael Assenat362600f2006-06-25 05:48:24 -0700333 retval = -ENODEV;
334 goto err_io;
335 }
336
André Goddard Rosaaf901ca2009-11-14 13:09:05 -0200337 /* Make sure frequency measurement mode, test modes, and lock
Raphael Assenat362600f2006-06-25 05:48:24 -0700338 * are all disabled */
339 v3020_set_reg(chip, V3020_STATUS_0, 0x0);
340
Mike Rapoport96615842009-04-02 16:57:01 -0700341 if (pdata->use_gpio)
342 dev_info(&pdev->dev, "Chip available at GPIOs "
343 "%d, %d, %d, %d\n",
344 chip->gpio[V3020_CS].gpio, chip->gpio[V3020_WR].gpio,
345 chip->gpio[V3020_RD].gpio, chip->gpio[V3020_IO].gpio);
346 else
347 dev_info(&pdev->dev, "Chip available at "
348 "physical address 0x%llx,"
349 "data connected to D%d\n",
350 (unsigned long long)pdev->resource[0].start,
351 chip->leftshift);
Raphael Assenat362600f2006-06-25 05:48:24 -0700352
353 platform_set_drvdata(pdev, chip);
354
Alessandro Zummob74d2ca2009-12-15 16:45:53 -0800355 chip->rtc = rtc_device_register("v3020",
Raphael Assenat362600f2006-06-25 05:48:24 -0700356 &pdev->dev, &v3020_rtc_ops, THIS_MODULE);
Alessandro Zummob74d2ca2009-12-15 16:45:53 -0800357 if (IS_ERR(chip->rtc)) {
358 retval = PTR_ERR(chip->rtc);
Raphael Assenat362600f2006-06-25 05:48:24 -0700359 goto err_io;
360 }
Raphael Assenat362600f2006-06-25 05:48:24 -0700361
362 return 0;
363
364err_io:
Mike Rapoport96615842009-04-02 16:57:01 -0700365 chip->ops->unmap_io(chip);
Raphael Assenat362600f2006-06-25 05:48:24 -0700366err_chip:
367 kfree(chip);
368
369 return retval;
370}
371
372static int rtc_remove(struct platform_device *dev)
373{
374 struct v3020 *chip = platform_get_drvdata(dev);
375 struct rtc_device *rtc = chip->rtc;
376
377 if (rtc)
378 rtc_device_unregister(rtc);
379
Mike Rapoport96615842009-04-02 16:57:01 -0700380 chip->ops->unmap_io(chip);
Raphael Assenat362600f2006-06-25 05:48:24 -0700381 kfree(chip);
382
383 return 0;
384}
385
386static struct platform_driver rtc_device_driver = {
387 .probe = rtc_probe,
388 .remove = rtc_remove,
389 .driver = {
390 .name = "v3020",
391 .owner = THIS_MODULE,
392 },
393};
394
395static __init int v3020_init(void)
396{
397 return platform_driver_register(&rtc_device_driver);
398}
399
400static __exit void v3020_exit(void)
401{
402 platform_driver_unregister(&rtc_device_driver);
403}
404
405module_init(v3020_init);
406module_exit(v3020_exit);
407
408MODULE_DESCRIPTION("V3020 RTC");
409MODULE_AUTHOR("Raphael Assenat");
410MODULE_LICENSE("GPL");
Kay Sieversad28a072008-04-10 21:29:25 -0700411MODULE_ALIAS("platform:v3020");