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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>
29
30#include <asm/io.h>
31
32#undef DEBUG
33
34struct v3020 {
35 void __iomem *ioaddress;
36 int leftshift;
37 struct rtc_device *rtc;
38};
39
40static void v3020_set_reg(struct v3020 *chip, unsigned char address,
41 unsigned char data)
42{
43 int i;
44 unsigned char tmp;
45
46 tmp = address;
47 for (i = 0; i < 4; i++) {
48 writel((tmp & 1) << chip->leftshift, chip->ioaddress);
49 tmp >>= 1;
50 }
51
52 /* Commands dont have data */
53 if (!V3020_IS_COMMAND(address)) {
54 for (i = 0; i < 8; i++) {
55 writel((data & 1) << chip->leftshift, chip->ioaddress);
56 data >>= 1;
57 }
58 }
59}
60
61static unsigned char v3020_get_reg(struct v3020 *chip, unsigned char address)
62{
63 unsigned int data=0;
64 int i;
65
66 for (i = 0; i < 4; i++) {
67 writel((address & 1) << chip->leftshift, chip->ioaddress);
68 address >>= 1;
69 }
70
71 for (i = 0; i < 8; i++) {
72 data >>= 1;
73 if (readl(chip->ioaddress) & (1 << chip->leftshift))
74 data |= 0x80;
75 }
76
77 return data;
78}
79
80static int v3020_read_time(struct device *dev, struct rtc_time *dt)
81{
82 struct v3020 *chip = dev_get_drvdata(dev);
83 int tmp;
84
85 /* Copy the current time to ram... */
86 v3020_set_reg(chip, V3020_CMD_CLOCK2RAM, 0);
87
88 /* ...and then read constant values. */
89 tmp = v3020_get_reg(chip, V3020_SECONDS);
90 dt->tm_sec = BCD2BIN(tmp);
91 tmp = v3020_get_reg(chip, V3020_MINUTES);
92 dt->tm_min = BCD2BIN(tmp);
93 tmp = v3020_get_reg(chip, V3020_HOURS);
94 dt->tm_hour = BCD2BIN(tmp);
95 tmp = v3020_get_reg(chip, V3020_MONTH_DAY);
96 dt->tm_mday = BCD2BIN(tmp);
97 tmp = v3020_get_reg(chip, V3020_MONTH);
98 dt->tm_mon = BCD2BIN(tmp);
99 tmp = v3020_get_reg(chip, V3020_WEEK_DAY);
100 dt->tm_wday = BCD2BIN(tmp);
101 tmp = v3020_get_reg(chip, V3020_YEAR);
102 dt->tm_year = BCD2BIN(tmp)+100;
103
104#ifdef DEBUG
105 printk("\n%s : Read RTC values\n",__FUNCTION__);
106 printk("tm_hour: %i\n",dt->tm_hour);
107 printk("tm_min : %i\n",dt->tm_min);
108 printk("tm_sec : %i\n",dt->tm_sec);
109 printk("tm_year: %i\n",dt->tm_year);
110 printk("tm_mon : %i\n",dt->tm_mon);
111 printk("tm_mday: %i\n",dt->tm_mday);
112 printk("tm_wday: %i\n",dt->tm_wday);
113#endif
114
115 return 0;
116}
117
118
119static int v3020_set_time(struct device *dev, struct rtc_time *dt)
120{
121 struct v3020 *chip = dev_get_drvdata(dev);
122
123#ifdef DEBUG
124 printk("\n%s : Setting RTC values\n",__FUNCTION__);
125 printk("tm_sec : %i\n",dt->tm_sec);
126 printk("tm_min : %i\n",dt->tm_min);
127 printk("tm_hour: %i\n",dt->tm_hour);
128 printk("tm_mday: %i\n",dt->tm_mday);
129 printk("tm_wday: %i\n",dt->tm_wday);
130 printk("tm_year: %i\n",dt->tm_year);
131#endif
132
133 /* Write all the values to ram... */
134 v3020_set_reg(chip, V3020_SECONDS, BIN2BCD(dt->tm_sec));
135 v3020_set_reg(chip, V3020_MINUTES, BIN2BCD(dt->tm_min));
136 v3020_set_reg(chip, V3020_HOURS, BIN2BCD(dt->tm_hour));
137 v3020_set_reg(chip, V3020_MONTH_DAY, BIN2BCD(dt->tm_mday));
138 v3020_set_reg(chip, V3020_MONTH, BIN2BCD(dt->tm_mon));
139 v3020_set_reg(chip, V3020_WEEK_DAY, BIN2BCD(dt->tm_wday));
140 v3020_set_reg(chip, V3020_YEAR, BIN2BCD(dt->tm_year % 100));
141
142 /* ...and set the clock. */
143 v3020_set_reg(chip, V3020_CMD_RAM2CLOCK, 0);
144
145 /* Compulab used this delay here. I dont know why,
146 * the datasheet does not specify a delay. */
147 /*mdelay(5);*/
148
149 return 0;
150}
151
David Brownellff8371a2006-09-30 23:28:17 -0700152static const struct rtc_class_ops v3020_rtc_ops = {
Raphael Assenat362600f2006-06-25 05:48:24 -0700153 .read_time = v3020_read_time,
154 .set_time = v3020_set_time,
155};
156
157static int rtc_probe(struct platform_device *pdev)
158{
159 struct v3020_platform_data *pdata = pdev->dev.platform_data;
160 struct v3020 *chip;
161 struct rtc_device *rtc;
162 int retval = -EBUSY;
163 int i;
164 int temp;
165
166 if (pdev->num_resources != 1)
167 return -EBUSY;
168
169 if (pdev->resource[0].flags != IORESOURCE_MEM)
170 return -EBUSY;
171
Raphael Assenat362600f2006-06-25 05:48:24 -0700172 chip = kzalloc(sizeof *chip, GFP_KERNEL);
173 if (!chip)
174 return -ENOMEM;
175
176 chip->leftshift = pdata->leftshift;
177 chip->ioaddress = ioremap(pdev->resource[0].start, 1);
178 if (chip->ioaddress == NULL)
179 goto err_chip;
180
181 /* Make sure the v3020 expects a communication cycle
182 * by reading 8 times */
183 for (i = 0; i < 8; i++)
184 temp = readl(chip->ioaddress);
185
186 /* Test chip by doing a write/read sequence
187 * to the chip ram */
188 v3020_set_reg(chip, V3020_SECONDS, 0x33);
189 if(v3020_get_reg(chip, V3020_SECONDS) != 0x33) {
190 retval = -ENODEV;
191 goto err_io;
192 }
193
194 /* Make sure frequency measurment mode, test modes, and lock
195 * are all disabled */
196 v3020_set_reg(chip, V3020_STATUS_0, 0x0);
197
Jeff Garzik6a15f462006-10-17 00:10:25 -0700198 dev_info(&pdev->dev, "Chip available at physical address 0x%llx,"
Raphael Assenat362600f2006-06-25 05:48:24 -0700199 "data connected to D%d\n",
Jeff Garzik6a15f462006-10-17 00:10:25 -0700200 (unsigned long long)pdev->resource[0].start,
Raphael Assenat362600f2006-06-25 05:48:24 -0700201 chip->leftshift);
202
203 platform_set_drvdata(pdev, chip);
204
205 rtc = rtc_device_register("v3020",
206 &pdev->dev, &v3020_rtc_ops, THIS_MODULE);
207 if (IS_ERR(rtc)) {
208 retval = PTR_ERR(rtc);
209 goto err_io;
210 }
211 chip->rtc = rtc;
212
213 return 0;
214
215err_io:
216 iounmap(chip->ioaddress);
217err_chip:
218 kfree(chip);
219
220 return retval;
221}
222
223static int rtc_remove(struct platform_device *dev)
224{
225 struct v3020 *chip = platform_get_drvdata(dev);
226 struct rtc_device *rtc = chip->rtc;
227
228 if (rtc)
229 rtc_device_unregister(rtc);
230
231 iounmap(chip->ioaddress);
232 kfree(chip);
233
234 return 0;
235}
236
237static struct platform_driver rtc_device_driver = {
238 .probe = rtc_probe,
239 .remove = rtc_remove,
240 .driver = {
241 .name = "v3020",
242 .owner = THIS_MODULE,
243 },
244};
245
246static __init int v3020_init(void)
247{
248 return platform_driver_register(&rtc_device_driver);
249}
250
251static __exit void v3020_exit(void)
252{
253 platform_driver_unregister(&rtc_device_driver);
254}
255
256module_init(v3020_init);
257module_exit(v3020_exit);
258
259MODULE_DESCRIPTION("V3020 RTC");
260MODULE_AUTHOR("Raphael Assenat");
261MODULE_LICENSE("GPL");