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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Faraday Technology FTRTC010 driver
4 *
5 * Copyright (C) 2009 Janos Laube <[email protected]>
6 *
7 * Original code for older kernel 2.6.15 are from Stormlinksemi
8 * first update from Janos Laube for > 2.6.29 kernels
9 *
10 * checkpatch fixes and usage of rtc-lib code
11 * Hans Ulli Kroll <[email protected]>
12 */
13
14#include <linux/rtc.h>
15#include <linux/io.h>
16#include <linux/slab.h>
17#include <linux/platform_device.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/clk.h>
21
22#define DRV_NAME "rtc-ftrtc010"
23
24MODULE_AUTHOR("Hans Ulli Kroll <[email protected]>");
25MODULE_DESCRIPTION("RTC driver for Gemini SoC");
26MODULE_LICENSE("GPL");
27MODULE_ALIAS("platform:" DRV_NAME);
28
29struct ftrtc010_rtc {
30 void __iomem *rtc_base;
31 int rtc_irq;
32 struct clk *pclk;
33 struct clk *extclk;
34};
35
36enum ftrtc010_rtc_offsets {
37 FTRTC010_RTC_SECOND = 0x00,
38 FTRTC010_RTC_MINUTE = 0x04,
39 FTRTC010_RTC_HOUR = 0x08,
40 FTRTC010_RTC_DAYS = 0x0C,
41 FTRTC010_RTC_ALARM_SECOND = 0x10,
42 FTRTC010_RTC_ALARM_MINUTE = 0x14,
43 FTRTC010_RTC_ALARM_HOUR = 0x18,
44 FTRTC010_RTC_RECORD = 0x1C,
45 FTRTC010_RTC_CR = 0x20,
46};
47
48static irqreturn_t ftrtc010_rtc_interrupt(int irq, void *dev)
49{
50 return IRQ_HANDLED;
51}
52
53/*
54 * Looks like the RTC in the Gemini SoC is (totaly) broken
55 * We can't read/write directly the time from RTC registers.
56 * We must do some "offset" calculation to get the real time
57 *
58 * This FIX works pretty fine and Stormlinksemi aka Cortina-Networks does
59 * the same thing, without the rtc-lib.c calls.
60 */
61
62static int ftrtc010_rtc_read_time(struct device *dev, struct rtc_time *tm)
63{
64 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
65
66 u32 days, hour, min, sec, offset;
67 timeu64_t time;
68
69 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
70 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
71 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
72 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
73 offset = readl(rtc->rtc_base + FTRTC010_RTC_RECORD);
74
75 time = offset + days * 86400 + hour * 3600 + min * 60 + sec;
76
77 rtc_time64_to_tm(time, tm);
78
79 return 0;
80}
81
82static int ftrtc010_rtc_set_time(struct device *dev, struct rtc_time *tm)
83{
84 struct ftrtc010_rtc *rtc = dev_get_drvdata(dev);
85 u32 sec, min, hour, day, offset;
86 timeu64_t time;
87
88 time = rtc_tm_to_time64(tm);
89
90 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
91 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
92 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
93 day = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
94
95 offset = time - (day * 86400 + hour * 3600 + min * 60 + sec);
96
97 writel(offset, rtc->rtc_base + FTRTC010_RTC_RECORD);
98 writel(0x01, rtc->rtc_base + FTRTC010_RTC_CR);
99
100 return 0;
101}
102
103static const struct rtc_class_ops ftrtc010_rtc_ops = {
104 .read_time = ftrtc010_rtc_read_time,
105 .set_time = ftrtc010_rtc_set_time,
106};
107
108static int ftrtc010_rtc_probe(struct platform_device *pdev)
109{
110 u32 days, hour, min, sec;
111 struct ftrtc010_rtc *rtc;
112 struct device *dev = &pdev->dev;
113 struct resource *res;
114 struct rtc_device *rtc_dev;
115 int ret;
116
117 rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
118 if (unlikely(!rtc))
119 return -ENOMEM;
120 platform_set_drvdata(pdev, rtc);
121
122 rtc->pclk = devm_clk_get(dev, "PCLK");
123 if (IS_ERR(rtc->pclk)) {
124 dev_err(dev, "could not get PCLK\n");
125 } else {
126 ret = clk_prepare_enable(rtc->pclk);
127 if (ret) {
128 dev_err(dev, "failed to enable PCLK\n");
129 return ret;
130 }
131 }
132 rtc->extclk = devm_clk_get(dev, "EXTCLK");
133 if (IS_ERR(rtc->extclk)) {
134 dev_err(dev, "could not get EXTCLK\n");
135 } else {
136 ret = clk_prepare_enable(rtc->extclk);
137 if (ret) {
138 dev_err(dev, "failed to enable EXTCLK\n");
139 goto err_disable_pclk;
140 }
141 }
142
143 rtc->rtc_irq = platform_get_irq(pdev, 0);
144 if (rtc->rtc_irq < 0) {
145 ret = rtc->rtc_irq;
146 goto err_disable_extclk;
147 }
148
149 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
150 if (!res) {
151 ret = -ENODEV;
152 goto err_disable_extclk;
153 }
154
155 rtc->rtc_base = devm_ioremap(dev, res->start,
156 resource_size(res));
157 if (!rtc->rtc_base) {
158 ret = -ENOMEM;
159 goto err_disable_extclk;
160 }
161
162 rtc_dev = devm_rtc_allocate_device(dev);
163 if (IS_ERR(rtc_dev)) {
164 ret = PTR_ERR(rtc_dev);
165 goto err_disable_extclk;
166 }
167
168 rtc_dev->ops = &ftrtc010_rtc_ops;
169
170 sec = readl(rtc->rtc_base + FTRTC010_RTC_SECOND);
171 min = readl(rtc->rtc_base + FTRTC010_RTC_MINUTE);
172 hour = readl(rtc->rtc_base + FTRTC010_RTC_HOUR);
173 days = readl(rtc->rtc_base + FTRTC010_RTC_DAYS);
174
175 rtc_dev->range_min = (u64)days * 86400 + hour * 3600 + min * 60 + sec;
176 rtc_dev->range_max = U32_MAX + rtc_dev->range_min;
177
178 ret = devm_request_irq(dev, rtc->rtc_irq, ftrtc010_rtc_interrupt,
179 IRQF_SHARED, pdev->name, dev);
180 if (unlikely(ret))
181 goto err_disable_extclk;
182
183 return devm_rtc_register_device(rtc_dev);
184
185err_disable_extclk:
186 clk_disable_unprepare(rtc->extclk);
187err_disable_pclk:
188 clk_disable_unprepare(rtc->pclk);
189 return ret;
190}
191
192static void ftrtc010_rtc_remove(struct platform_device *pdev)
193{
194 struct ftrtc010_rtc *rtc = platform_get_drvdata(pdev);
195
196 if (!IS_ERR(rtc->extclk))
197 clk_disable_unprepare(rtc->extclk);
198 if (!IS_ERR(rtc->pclk))
199 clk_disable_unprepare(rtc->pclk);
200}
201
202static const struct of_device_id ftrtc010_rtc_dt_match[] = {
203 { .compatible = "cortina,gemini-rtc" },
204 { .compatible = "faraday,ftrtc010" },
205 { }
206};
207MODULE_DEVICE_TABLE(of, ftrtc010_rtc_dt_match);
208
209static struct platform_driver ftrtc010_rtc_driver = {
210 .driver = {
211 .name = DRV_NAME,
212 .of_match_table = ftrtc010_rtc_dt_match,
213 },
214 .probe = ftrtc010_rtc_probe,
215 .remove = ftrtc010_rtc_remove,
216};
217
218module_platform_driver_probe(ftrtc010_rtc_driver, ftrtc010_rtc_probe);