Loading...
Note: File does not exist in v6.8.
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#include <linux/slab.h>
32
33#include <linux/io.h>
34
35#undef DEBUG
36
37struct v3020;
38
39struct v3020_chip_ops {
40 int (*map_io)(struct v3020 *chip, struct platform_device *pdev,
41 struct v3020_platform_data *pdata);
42 void (*unmap_io)(struct v3020 *chip);
43 unsigned char (*read_bit)(struct v3020 *chip);
44 void (*write_bit)(struct v3020 *chip, unsigned char bit);
45};
46
47#define V3020_CS 0
48#define V3020_WR 1
49#define V3020_RD 2
50#define V3020_IO 3
51
52struct v3020 {
53 /* MMIO access */
54 void __iomem *ioaddress;
55 int leftshift;
56
57 /* GPIO access */
58 struct gpio *gpio;
59
60 const struct v3020_chip_ops *ops;
61
62 struct rtc_device *rtc;
63};
64
65
66static int v3020_mmio_map(struct v3020 *chip, struct platform_device *pdev,
67 struct v3020_platform_data *pdata)
68{
69 if (pdev->num_resources != 1)
70 return -EBUSY;
71
72 if (pdev->resource[0].flags != IORESOURCE_MEM)
73 return -EBUSY;
74
75 chip->leftshift = pdata->leftshift;
76 chip->ioaddress = ioremap(pdev->resource[0].start, 1);
77 if (chip->ioaddress == NULL)
78 return -EBUSY;
79
80 return 0;
81}
82
83static void v3020_mmio_unmap(struct v3020 *chip)
84{
85 iounmap(chip->ioaddress);
86}
87
88static void v3020_mmio_write_bit(struct v3020 *chip, unsigned char bit)
89{
90 writel(bit << chip->leftshift, chip->ioaddress);
91}
92
93static unsigned char v3020_mmio_read_bit(struct v3020 *chip)
94{
95 return !!(readl(chip->ioaddress) & (1 << chip->leftshift));
96}
97
98static const struct v3020_chip_ops v3020_mmio_ops = {
99 .map_io = v3020_mmio_map,
100 .unmap_io = v3020_mmio_unmap,
101 .read_bit = v3020_mmio_read_bit,
102 .write_bit = v3020_mmio_write_bit,
103};
104
105static struct gpio v3020_gpio[] = {
106 { 0, GPIOF_OUT_INIT_HIGH, "RTC CS"},
107 { 0, GPIOF_OUT_INIT_HIGH, "RTC WR"},
108 { 0, GPIOF_OUT_INIT_HIGH, "RTC RD"},
109 { 0, GPIOF_OUT_INIT_HIGH, "RTC IO"},
110};
111
112static int v3020_gpio_map(struct v3020 *chip, struct platform_device *pdev,
113 struct v3020_platform_data *pdata)
114{
115 int err;
116
117 v3020_gpio[V3020_CS].gpio = pdata->gpio_cs;
118 v3020_gpio[V3020_WR].gpio = pdata->gpio_wr;
119 v3020_gpio[V3020_RD].gpio = pdata->gpio_rd;
120 v3020_gpio[V3020_IO].gpio = pdata->gpio_io;
121
122 err = gpio_request_array(v3020_gpio, ARRAY_SIZE(v3020_gpio));
123
124 if (!err)
125 chip->gpio = v3020_gpio;
126
127 return err;
128}
129
130static void v3020_gpio_unmap(struct v3020 *chip)
131{
132 gpio_free_array(v3020_gpio, ARRAY_SIZE(v3020_gpio));
133}
134
135static void v3020_gpio_write_bit(struct v3020 *chip, unsigned char bit)
136{
137 gpio_direction_output(chip->gpio[V3020_IO].gpio, bit);
138 gpio_set_value(chip->gpio[V3020_CS].gpio, 0);
139 gpio_set_value(chip->gpio[V3020_WR].gpio, 0);
140 udelay(1);
141 gpio_set_value(chip->gpio[V3020_WR].gpio, 1);
142 gpio_set_value(chip->gpio[V3020_CS].gpio, 1);
143}
144
145static unsigned char v3020_gpio_read_bit(struct v3020 *chip)
146{
147 int bit;
148
149 gpio_direction_input(chip->gpio[V3020_IO].gpio);
150 gpio_set_value(chip->gpio[V3020_CS].gpio, 0);
151 gpio_set_value(chip->gpio[V3020_RD].gpio, 0);
152 udelay(1);
153 bit = !!gpio_get_value(chip->gpio[V3020_IO].gpio);
154 udelay(1);
155 gpio_set_value(chip->gpio[V3020_RD].gpio, 1);
156 gpio_set_value(chip->gpio[V3020_CS].gpio, 1);
157
158 return bit;
159}
160
161static const struct v3020_chip_ops v3020_gpio_ops = {
162 .map_io = v3020_gpio_map,
163 .unmap_io = v3020_gpio_unmap,
164 .read_bit = v3020_gpio_read_bit,
165 .write_bit = v3020_gpio_write_bit,
166};
167
168static void v3020_set_reg(struct v3020 *chip, unsigned char address,
169 unsigned char data)
170{
171 int i;
172 unsigned char tmp;
173
174 tmp = address;
175 for (i = 0; i < 4; i++) {
176 chip->ops->write_bit(chip, (tmp & 1));
177 tmp >>= 1;
178 udelay(1);
179 }
180
181 /* Commands dont have data */
182 if (!V3020_IS_COMMAND(address)) {
183 for (i = 0; i < 8; i++) {
184 chip->ops->write_bit(chip, (data & 1));
185 data >>= 1;
186 udelay(1);
187 }
188 }
189}
190
191static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address)
192{
193 unsigned int data = 0;
194 int i;
195
196 for (i = 0; i < 4; i++) {
197 chip->ops->write_bit(chip, (address & 1));
198 address >>= 1;
199 udelay(1);
200 }
201
202 for (i = 0; i < 8; i++) {
203 data >>= 1;
204 if (chip->ops->read_bit(chip))
205 data |= 0x80;
206 udelay(1);
207 }
208
209 return data;
210}
211
212static int v3020_read_time(struct device *dev, struct rtc_time *dt)
213{
214 struct v3020 *chip = dev_get_drvdata(dev);
215 int tmp;
216
217 /* Copy the current time to ram... */
218 v3020_set_reg(chip, V3020_CMD_CLOCK2RAM, 0);
219
220 /* ...and then read constant values. */
221 tmp = v3020_get_reg(chip, V3020_SECONDS);
222 dt->tm_sec = bcd2bin(tmp);
223 tmp = v3020_get_reg(chip, V3020_MINUTES);
224 dt->tm_min = bcd2bin(tmp);
225 tmp = v3020_get_reg(chip, V3020_HOURS);
226 dt->tm_hour = bcd2bin(tmp);
227 tmp = v3020_get_reg(chip, V3020_MONTH_DAY);
228 dt->tm_mday = bcd2bin(tmp);
229 tmp = v3020_get_reg(chip, V3020_MONTH);
230 dt->tm_mon = bcd2bin(tmp) - 1;
231 tmp = v3020_get_reg(chip, V3020_WEEK_DAY);
232 dt->tm_wday = bcd2bin(tmp);
233 tmp = v3020_get_reg(chip, V3020_YEAR);
234 dt->tm_year = bcd2bin(tmp)+100;
235
236 dev_dbg(dev, "\n%s : Read RTC values\n", __func__);
237 dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
238 dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
239 dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
240 dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
241 dev_dbg(dev, "tm_mon : %i\n", dt->tm_mon);
242 dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
243 dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
244
245 return 0;
246}
247
248
249static int v3020_set_time(struct device *dev, struct rtc_time *dt)
250{
251 struct v3020 *chip = dev_get_drvdata(dev);
252
253 dev_dbg(dev, "\n%s : Setting RTC values\n", __func__);
254 dev_dbg(dev, "tm_sec : %i\n", dt->tm_sec);
255 dev_dbg(dev, "tm_min : %i\n", dt->tm_min);
256 dev_dbg(dev, "tm_hour: %i\n", dt->tm_hour);
257 dev_dbg(dev, "tm_mday: %i\n", dt->tm_mday);
258 dev_dbg(dev, "tm_wday: %i\n", dt->tm_wday);
259 dev_dbg(dev, "tm_year: %i\n", dt->tm_year);
260
261 /* Write all the values to ram... */
262 v3020_set_reg(chip, V3020_SECONDS, bin2bcd(dt->tm_sec));
263 v3020_set_reg(chip, V3020_MINUTES, bin2bcd(dt->tm_min));
264 v3020_set_reg(chip, V3020_HOURS, bin2bcd(dt->tm_hour));
265 v3020_set_reg(chip, V3020_MONTH_DAY, bin2bcd(dt->tm_mday));
266 v3020_set_reg(chip, V3020_MONTH, bin2bcd(dt->tm_mon + 1));
267 v3020_set_reg(chip, V3020_WEEK_DAY, bin2bcd(dt->tm_wday));
268 v3020_set_reg(chip, V3020_YEAR, bin2bcd(dt->tm_year % 100));
269
270 /* ...and set the clock. */
271 v3020_set_reg(chip, V3020_CMD_RAM2CLOCK, 0);
272
273 /* Compulab used this delay here. I dont know why,
274 * the datasheet does not specify a delay. */
275 /*mdelay(5);*/
276
277 return 0;
278}
279
280static const struct rtc_class_ops v3020_rtc_ops = {
281 .read_time = v3020_read_time,
282 .set_time = v3020_set_time,
283};
284
285static int rtc_probe(struct platform_device *pdev)
286{
287 struct v3020_platform_data *pdata = dev_get_platdata(&pdev->dev);
288 struct v3020 *chip;
289 int retval = -EBUSY;
290 int i;
291 int temp;
292
293 chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
294 if (!chip)
295 return -ENOMEM;
296
297 if (pdata->use_gpio)
298 chip->ops = &v3020_gpio_ops;
299 else
300 chip->ops = &v3020_mmio_ops;
301
302 retval = chip->ops->map_io(chip, pdev, pdata);
303 if (retval)
304 return retval;
305
306 /* Make sure the v3020 expects a communication cycle
307 * by reading 8 times */
308 for (i = 0; i < 8; i++)
309 temp = chip->ops->read_bit(chip);
310
311 /* Test chip by doing a write/read sequence
312 * to the chip ram */
313 v3020_set_reg(chip, V3020_SECONDS, 0x33);
314 if (v3020_get_reg(chip, V3020_SECONDS) != 0x33) {
315 retval = -ENODEV;
316 goto err_io;
317 }
318
319 /* Make sure frequency measurement mode, test modes, and lock
320 * are all disabled */
321 v3020_set_reg(chip, V3020_STATUS_0, 0x0);
322
323 if (pdata->use_gpio)
324 dev_info(&pdev->dev, "Chip available at GPIOs "
325 "%d, %d, %d, %d\n",
326 chip->gpio[V3020_CS].gpio, chip->gpio[V3020_WR].gpio,
327 chip->gpio[V3020_RD].gpio, chip->gpio[V3020_IO].gpio);
328 else
329 dev_info(&pdev->dev, "Chip available at "
330 "physical address 0x%llx,"
331 "data connected to D%d\n",
332 (unsigned long long)pdev->resource[0].start,
333 chip->leftshift);
334
335 platform_set_drvdata(pdev, chip);
336
337 chip->rtc = devm_rtc_device_register(&pdev->dev, "v3020",
338 &v3020_rtc_ops, THIS_MODULE);
339 if (IS_ERR(chip->rtc)) {
340 retval = PTR_ERR(chip->rtc);
341 goto err_io;
342 }
343
344 return 0;
345
346err_io:
347 chip->ops->unmap_io(chip);
348
349 return retval;
350}
351
352static int rtc_remove(struct platform_device *dev)
353{
354 struct v3020 *chip = platform_get_drvdata(dev);
355
356 chip->ops->unmap_io(chip);
357
358 return 0;
359}
360
361static struct platform_driver rtc_device_driver = {
362 .probe = rtc_probe,
363 .remove = rtc_remove,
364 .driver = {
365 .name = "v3020",
366 },
367};
368
369module_platform_driver(rtc_device_driver);
370
371MODULE_DESCRIPTION("V3020 RTC");
372MODULE_AUTHOR("Raphael Assenat");
373MODULE_LICENSE("GPL");
374MODULE_ALIAS("platform:v3020");