1 // SPDX-License-Identifier: GPL-2.0
3 * TX4939 internal RTC driver
4 * Based on RBTX49xx patch from CELF patch archive.
6 * (C) Copyright TOSHIBA CORPORATION 2005-2007
9 #include <linux/platform_device.h>
10 #include <linux/interrupt.h>
11 #include <linux/module.h>
13 #include <linux/gfp.h>
15 #define TX4939_RTCCTL_ALME 0x00000080
16 #define TX4939_RTCCTL_ALMD 0x00000040
17 #define TX4939_RTCCTL_BUSY 0x00000020
19 #define TX4939_RTCCTL_COMMAND 0x00000007
20 #define TX4939_RTCCTL_COMMAND_NOP 0x00000000
21 #define TX4939_RTCCTL_COMMAND_GETTIME 0x00000001
22 #define TX4939_RTCCTL_COMMAND_SETTIME 0x00000002
23 #define TX4939_RTCCTL_COMMAND_GETALARM 0x00000003
24 #define TX4939_RTCCTL_COMMAND_SETALARM 0x00000004
26 #define TX4939_RTCTBC_PM 0x00000080
27 #define TX4939_RTCTBC_COMP 0x0000007f
29 #define TX4939_RTC_REG_RAMSIZE 0x00000100
30 #define TX4939_RTC_REG_RWBSIZE 0x00000006
32 struct tx4939_rtc_reg {
39 struct tx4939rtc_plat_data {
40 struct rtc_device *rtc;
41 struct tx4939_rtc_reg __iomem *rtcreg;
45 static struct tx4939rtc_plat_data *get_tx4939rtc_plat_data(struct device *dev)
47 return platform_get_drvdata(to_platform_device(dev));
50 static int tx4939_rtc_cmd(struct tx4939_rtc_reg __iomem *rtcreg, int cmd)
54 __raw_writel(cmd, &rtcreg->ctl);
55 /* This might take 30us (next 32.768KHz clock) */
56 while (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_BUSY) {
57 /* timeout on approx. 100us (@ GBUS200MHz) */
65 static int tx4939_rtc_set_time(struct device *dev, struct rtc_time *tm)
67 struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
68 struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
69 unsigned long secs = rtc_tm_to_time64(tm);
79 spin_lock_irq(&pdata->lock);
80 __raw_writel(0, &rtcreg->adr);
81 for (i = 0; i < 6; i++)
82 __raw_writel(buf[i], &rtcreg->dat);
83 ret = tx4939_rtc_cmd(rtcreg,
84 TX4939_RTCCTL_COMMAND_SETTIME |
85 (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
86 spin_unlock_irq(&pdata->lock);
90 static int tx4939_rtc_read_time(struct device *dev, struct rtc_time *tm)
92 struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
93 struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
98 spin_lock_irq(&pdata->lock);
99 ret = tx4939_rtc_cmd(rtcreg,
100 TX4939_RTCCTL_COMMAND_GETTIME |
101 (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
103 spin_unlock_irq(&pdata->lock);
106 __raw_writel(2, &rtcreg->adr);
107 for (i = 2; i < 6; i++)
108 buf[i] = __raw_readl(&rtcreg->dat);
109 spin_unlock_irq(&pdata->lock);
110 sec = ((unsigned long)buf[5] << 24) | (buf[4] << 16) |
111 (buf[3] << 8) | buf[2];
112 rtc_time64_to_tm(sec, tm);
116 static int tx4939_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
118 struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
119 struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
122 unsigned char buf[6];
124 sec = rtc_tm_to_time64(&alrm->time);
131 spin_lock_irq(&pdata->lock);
132 __raw_writel(0, &rtcreg->adr);
133 for (i = 0; i < 6; i++)
134 __raw_writel(buf[i], &rtcreg->dat);
135 ret = tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_SETALARM |
136 (alrm->enabled ? TX4939_RTCCTL_ALME : 0));
137 spin_unlock_irq(&pdata->lock);
141 static int tx4939_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
143 struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
144 struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
147 unsigned char buf[6];
150 spin_lock_irq(&pdata->lock);
151 ret = tx4939_rtc_cmd(rtcreg,
152 TX4939_RTCCTL_COMMAND_GETALARM |
153 (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALME));
155 spin_unlock_irq(&pdata->lock);
158 __raw_writel(2, &rtcreg->adr);
159 for (i = 2; i < 6; i++)
160 buf[i] = __raw_readl(&rtcreg->dat);
161 ctl = __raw_readl(&rtcreg->ctl);
162 alrm->enabled = (ctl & TX4939_RTCCTL_ALME) ? 1 : 0;
163 alrm->pending = (ctl & TX4939_RTCCTL_ALMD) ? 1 : 0;
164 spin_unlock_irq(&pdata->lock);
165 sec = ((unsigned long)buf[5] << 24) | (buf[4] << 16) |
166 (buf[3] << 8) | buf[2];
167 rtc_time64_to_tm(sec, &alrm->time);
168 return rtc_valid_tm(&alrm->time);
171 static int tx4939_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
173 struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev);
175 spin_lock_irq(&pdata->lock);
176 tx4939_rtc_cmd(pdata->rtcreg,
177 TX4939_RTCCTL_COMMAND_NOP |
178 (enabled ? TX4939_RTCCTL_ALME : 0));
179 spin_unlock_irq(&pdata->lock);
183 static irqreturn_t tx4939_rtc_interrupt(int irq, void *dev_id)
185 struct tx4939rtc_plat_data *pdata = get_tx4939rtc_plat_data(dev_id);
186 struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
187 unsigned long events = RTC_IRQF;
189 spin_lock(&pdata->lock);
190 if (__raw_readl(&rtcreg->ctl) & TX4939_RTCCTL_ALMD) {
192 tx4939_rtc_cmd(rtcreg, TX4939_RTCCTL_COMMAND_NOP);
194 spin_unlock(&pdata->lock);
195 rtc_update_irq(pdata->rtc, 1, events);
200 static const struct rtc_class_ops tx4939_rtc_ops = {
201 .read_time = tx4939_rtc_read_time,
202 .read_alarm = tx4939_rtc_read_alarm,
203 .set_alarm = tx4939_rtc_set_alarm,
204 .set_time = tx4939_rtc_set_time,
205 .alarm_irq_enable = tx4939_rtc_alarm_irq_enable,
208 static int tx4939_nvram_read(void *priv, unsigned int pos, void *val,
211 struct tx4939rtc_plat_data *pdata = priv;
212 struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
215 spin_lock_irq(&pdata->lock);
216 for (; bytes; bytes--) {
217 __raw_writel(pos++, &rtcreg->adr);
218 *buf++ = __raw_readl(&rtcreg->dat);
220 spin_unlock_irq(&pdata->lock);
224 static int tx4939_nvram_write(void *priv, unsigned int pos, void *val,
227 struct tx4939rtc_plat_data *pdata = priv;
228 struct tx4939_rtc_reg __iomem *rtcreg = pdata->rtcreg;
231 spin_lock_irq(&pdata->lock);
232 for (; bytes; bytes--) {
233 __raw_writel(pos++, &rtcreg->adr);
234 __raw_writel(*buf++, &rtcreg->dat);
236 spin_unlock_irq(&pdata->lock);
240 static int __init tx4939_rtc_probe(struct platform_device *pdev)
242 struct rtc_device *rtc;
243 struct tx4939rtc_plat_data *pdata;
244 struct resource *res;
246 struct nvmem_config nvmem_cfg = {
247 .name = "tx4939_nvram",
248 .size = TX4939_RTC_REG_RAMSIZE,
249 .reg_read = tx4939_nvram_read,
250 .reg_write = tx4939_nvram_write,
253 irq = platform_get_irq(pdev, 0);
256 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
259 platform_set_drvdata(pdev, pdata);
261 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
262 pdata->rtcreg = devm_ioremap_resource(&pdev->dev, res);
263 if (IS_ERR(pdata->rtcreg))
264 return PTR_ERR(pdata->rtcreg);
266 spin_lock_init(&pdata->lock);
267 tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
268 if (devm_request_irq(&pdev->dev, irq, tx4939_rtc_interrupt,
269 0, pdev->name, &pdev->dev) < 0)
271 rtc = devm_rtc_allocate_device(&pdev->dev);
275 rtc->ops = &tx4939_rtc_ops;
276 rtc->nvram_old_abi = true;
277 rtc->range_max = U32_MAX;
281 nvmem_cfg.priv = pdata;
282 ret = rtc_nvmem_register(rtc, &nvmem_cfg);
286 return rtc_register_device(rtc);
289 static int __exit tx4939_rtc_remove(struct platform_device *pdev)
291 struct tx4939rtc_plat_data *pdata = platform_get_drvdata(pdev);
293 spin_lock_irq(&pdata->lock);
294 tx4939_rtc_cmd(pdata->rtcreg, TX4939_RTCCTL_COMMAND_NOP);
295 spin_unlock_irq(&pdata->lock);
299 static struct platform_driver tx4939_rtc_driver = {
300 .remove = __exit_p(tx4939_rtc_remove),
306 module_platform_driver_probe(tx4939_rtc_driver, tx4939_rtc_probe);
308 MODULE_AUTHOR("Atsushi Nemoto <anemo@mba.ocn.ne.jp>");
309 MODULE_DESCRIPTION("TX4939 internal RTC driver");
310 MODULE_LICENSE("GPL v2");
311 MODULE_ALIAS("platform:tx4939rtc");