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1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * The RTC driver for Sunplus SP7021
5 *
6 * Copyright (C) 2019 Sunplus Technology Inc., All rights reseerved.
7 */
8
9#include <linux/bitfield.h>
10#include <linux/clk.h>
11#include <linux/err.h>
12#include <linux/io.h>
13#include <linux/ktime.h>
14#include <linux/module.h>
15#include <linux/of.h>
16#include <linux/platform_device.h>
17#include <linux/reset.h>
18#include <linux/rtc.h>
19
20#define RTC_REG_NAME "rtc"
21
22#define RTC_CTRL 0x40
23#define TIMER_FREEZE_MASK_BIT BIT(5 + 16)
24#define TIMER_FREEZE BIT(5)
25#define DIS_SYS_RST_RTC_MASK_BIT BIT(4 + 16)
26#define DIS_SYS_RST_RTC BIT(4)
27#define RTC32K_MODE_RESET_MASK_BIT BIT(3 + 16)
28#define RTC32K_MODE_RESET BIT(3)
29#define ALARM_EN_OVERDUE_MASK_BIT BIT(2 + 16)
30#define ALARM_EN_OVERDUE BIT(2)
31#define ALARM_EN_PMC_MASK_BIT BIT(1 + 16)
32#define ALARM_EN_PMC BIT(1)
33#define ALARM_EN_MASK_BIT BIT(0 + 16)
34#define ALARM_EN BIT(0)
35#define RTC_TIMER_OUT 0x44
36#define RTC_DIVIDER 0x48
37#define RTC_TIMER_SET 0x4c
38#define RTC_ALARM_SET 0x50
39#define RTC_USER_DATA 0x54
40#define RTC_RESET_RECORD 0x58
41#define RTC_BATT_CHARGE_CTRL 0x5c
42#define BAT_CHARGE_RSEL_MASK_BIT GENMASK(3 + 16, 2 + 16)
43#define BAT_CHARGE_RSEL_MASK GENMASK(3, 2)
44#define BAT_CHARGE_RSEL_2K_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 0)
45#define BAT_CHARGE_RSEL_250_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 1)
46#define BAT_CHARGE_RSEL_50_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 2)
47#define BAT_CHARGE_RSEL_0_OHM FIELD_PREP(BAT_CHARGE_RSEL_MASK, 3)
48#define BAT_CHARGE_DSEL_MASK_BIT BIT(1 + 16)
49#define BAT_CHARGE_DSEL_MASK GENMASK(1, 1)
50#define BAT_CHARGE_DSEL_ON FIELD_PREP(BAT_CHARGE_DSEL_MASK, 0)
51#define BAT_CHARGE_DSEL_OFF FIELD_PREP(BAT_CHARGE_DSEL_MASK, 1)
52#define BAT_CHARGE_EN_MASK_BIT BIT(0 + 16)
53#define BAT_CHARGE_EN BIT(0)
54#define RTC_TRIM_CTRL 0x60
55
56struct sunplus_rtc {
57 struct rtc_device *rtc;
58 struct resource *res;
59 struct clk *rtcclk;
60 struct reset_control *rstc;
61 void __iomem *reg_base;
62 int irq;
63};
64
65static void sp_get_seconds(struct device *dev, unsigned long *secs)
66{
67 struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
68
69 *secs = (unsigned long)readl(sp_rtc->reg_base + RTC_TIMER_OUT);
70}
71
72static void sp_set_seconds(struct device *dev, unsigned long secs)
73{
74 struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
75
76 writel((u32)secs, sp_rtc->reg_base + RTC_TIMER_SET);
77}
78
79static int sp_rtc_read_time(struct device *dev, struct rtc_time *tm)
80{
81 unsigned long secs;
82
83 sp_get_seconds(dev, &secs);
84 rtc_time64_to_tm(secs, tm);
85
86 return 0;
87}
88
89static int sp_rtc_set_time(struct device *dev, struct rtc_time *tm)
90{
91 unsigned long secs;
92
93 secs = rtc_tm_to_time64(tm);
94 dev_dbg(dev, "%s, secs = %lu\n", __func__, secs);
95 sp_set_seconds(dev, secs);
96
97 return 0;
98}
99
100static int sp_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
101{
102 struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
103 unsigned long alarm_time;
104
105 alarm_time = rtc_tm_to_time64(&alrm->time);
106 dev_dbg(dev, "%s, alarm_time: %u\n", __func__, (u32)(alarm_time));
107 writel((u32)alarm_time, sp_rtc->reg_base + RTC_ALARM_SET);
108
109 return 0;
110}
111
112static int sp_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
113{
114 struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
115 unsigned int alarm_time;
116
117 alarm_time = readl(sp_rtc->reg_base + RTC_ALARM_SET);
118 dev_dbg(dev, "%s, alarm_time: %u\n", __func__, alarm_time);
119
120 if (alarm_time == 0)
121 alrm->enabled = 0;
122 else
123 alrm->enabled = 1;
124
125 rtc_time64_to_tm((unsigned long)(alarm_time), &alrm->time);
126
127 return 0;
128}
129
130static int sp_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
131{
132 struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
133
134 if (enabled)
135 writel((TIMER_FREEZE_MASK_BIT | DIS_SYS_RST_RTC_MASK_BIT |
136 RTC32K_MODE_RESET_MASK_BIT | ALARM_EN_OVERDUE_MASK_BIT |
137 ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) |
138 (DIS_SYS_RST_RTC | ALARM_EN_OVERDUE | ALARM_EN_PMC | ALARM_EN),
139 sp_rtc->reg_base + RTC_CTRL);
140 else
141 writel((ALARM_EN_OVERDUE_MASK_BIT | ALARM_EN_PMC_MASK_BIT | ALARM_EN_MASK_BIT) |
142 0x0, sp_rtc->reg_base + RTC_CTRL);
143
144 return 0;
145}
146
147static const struct rtc_class_ops sp_rtc_ops = {
148 .read_time = sp_rtc_read_time,
149 .set_time = sp_rtc_set_time,
150 .set_alarm = sp_rtc_set_alarm,
151 .read_alarm = sp_rtc_read_alarm,
152 .alarm_irq_enable = sp_rtc_alarm_irq_enable,
153};
154
155static irqreturn_t sp_rtc_irq_handler(int irq, void *dev_id)
156{
157 struct platform_device *plat_dev = dev_id;
158 struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev);
159
160 rtc_update_irq(sp_rtc->rtc, 1, RTC_IRQF | RTC_AF);
161 dev_dbg(&plat_dev->dev, "[RTC] ALARM INT\n");
162
163 return IRQ_HANDLED;
164}
165
166/*
167 * -------------------------------------------------------------------------------------
168 * bat_charge_rsel bat_charge_dsel bat_charge_en Remarks
169 * x x 0 Disable
170 * 0 0 1 0.86mA (2K Ohm with diode)
171 * 1 0 1 1.81mA (250 Ohm with diode)
172 * 2 0 1 2.07mA (50 Ohm with diode)
173 * 3 0 1 16.0mA (0 Ohm with diode)
174 * 0 1 1 1.36mA (2K Ohm without diode)
175 * 1 1 1 3.99mA (250 Ohm without diode)
176 * 2 1 1 4.41mA (50 Ohm without diode)
177 * 3 1 1 16.0mA (0 Ohm without diode)
178 * -------------------------------------------------------------------------------------
179 */
180static void sp_rtc_set_trickle_charger(struct device dev)
181{
182 struct sunplus_rtc *sp_rtc = dev_get_drvdata(&dev);
183 u32 ohms, rsel;
184 u32 chargeable;
185
186 if (of_property_read_u32(dev.of_node, "trickle-resistor-ohms", &ohms) ||
187 of_property_read_u32(dev.of_node, "aux-voltage-chargeable", &chargeable)) {
188 dev_warn(&dev, "battery charger disabled\n");
189 return;
190 }
191
192 switch (ohms) {
193 case 2000:
194 rsel = BAT_CHARGE_RSEL_2K_OHM;
195 break;
196 case 250:
197 rsel = BAT_CHARGE_RSEL_250_OHM;
198 break;
199 case 50:
200 rsel = BAT_CHARGE_RSEL_50_OHM;
201 break;
202 case 0:
203 rsel = BAT_CHARGE_RSEL_0_OHM;
204 break;
205 default:
206 dev_err(&dev, "invalid charger resistor value (%d)\n", ohms);
207 return;
208 }
209
210 writel(BAT_CHARGE_RSEL_MASK_BIT | rsel, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
211
212 switch (chargeable) {
213 case 0:
214 writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_OFF,
215 sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
216 break;
217 case 1:
218 writel(BAT_CHARGE_DSEL_MASK_BIT | BAT_CHARGE_DSEL_ON,
219 sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
220 break;
221 default:
222 dev_err(&dev, "invalid aux-voltage-chargeable value (%d)\n", chargeable);
223 return;
224 }
225
226 writel(BAT_CHARGE_EN_MASK_BIT | BAT_CHARGE_EN, sp_rtc->reg_base + RTC_BATT_CHARGE_CTRL);
227}
228
229static int sp_rtc_probe(struct platform_device *plat_dev)
230{
231 struct sunplus_rtc *sp_rtc;
232 int ret;
233
234 sp_rtc = devm_kzalloc(&plat_dev->dev, sizeof(*sp_rtc), GFP_KERNEL);
235 if (!sp_rtc)
236 return -ENOMEM;
237
238 sp_rtc->reg_base = devm_platform_ioremap_resource_byname(plat_dev, RTC_REG_NAME);
239 if (IS_ERR(sp_rtc->reg_base))
240 return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->reg_base),
241 "%s devm_ioremap_resource fail\n", RTC_REG_NAME);
242 dev_dbg(&plat_dev->dev, "res = %pR, reg_base = %p\n",
243 sp_rtc->res, sp_rtc->reg_base);
244
245 sp_rtc->irq = platform_get_irq(plat_dev, 0);
246 if (sp_rtc->irq < 0)
247 return sp_rtc->irq;
248
249 ret = devm_request_irq(&plat_dev->dev, sp_rtc->irq, sp_rtc_irq_handler,
250 IRQF_TRIGGER_RISING, "rtc irq", plat_dev);
251 if (ret)
252 return dev_err_probe(&plat_dev->dev, ret, "devm_request_irq failed:\n");
253
254 sp_rtc->rtcclk = devm_clk_get(&plat_dev->dev, NULL);
255 if (IS_ERR(sp_rtc->rtcclk))
256 return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rtcclk),
257 "devm_clk_get fail\n");
258
259 sp_rtc->rstc = devm_reset_control_get_exclusive(&plat_dev->dev, NULL);
260 if (IS_ERR(sp_rtc->rstc))
261 return dev_err_probe(&plat_dev->dev, PTR_ERR(sp_rtc->rstc),
262 "failed to retrieve reset controller\n");
263
264 ret = clk_prepare_enable(sp_rtc->rtcclk);
265 if (ret)
266 goto free_clk;
267
268 ret = reset_control_deassert(sp_rtc->rstc);
269 if (ret)
270 goto free_reset_assert;
271
272 device_init_wakeup(&plat_dev->dev, true);
273 dev_set_drvdata(&plat_dev->dev, sp_rtc);
274
275 sp_rtc->rtc = devm_rtc_allocate_device(&plat_dev->dev);
276 if (IS_ERR(sp_rtc->rtc)) {
277 ret = PTR_ERR(sp_rtc->rtc);
278 goto free_reset_assert;
279 }
280
281 sp_rtc->rtc->range_max = U32_MAX;
282 sp_rtc->rtc->range_min = 0;
283 sp_rtc->rtc->ops = &sp_rtc_ops;
284
285 ret = devm_rtc_register_device(sp_rtc->rtc);
286 if (ret)
287 goto free_reset_assert;
288
289 /* Setup trickle charger */
290 if (plat_dev->dev.of_node)
291 sp_rtc_set_trickle_charger(plat_dev->dev);
292
293 /* Keep RTC from system reset */
294 writel(DIS_SYS_RST_RTC_MASK_BIT | DIS_SYS_RST_RTC, sp_rtc->reg_base + RTC_CTRL);
295
296 return 0;
297
298free_reset_assert:
299 reset_control_assert(sp_rtc->rstc);
300free_clk:
301 clk_disable_unprepare(sp_rtc->rtcclk);
302
303 return ret;
304}
305
306static void sp_rtc_remove(struct platform_device *plat_dev)
307{
308 struct sunplus_rtc *sp_rtc = dev_get_drvdata(&plat_dev->dev);
309
310 device_init_wakeup(&plat_dev->dev, false);
311 reset_control_assert(sp_rtc->rstc);
312 clk_disable_unprepare(sp_rtc->rtcclk);
313}
314
315#ifdef CONFIG_PM_SLEEP
316static int sp_rtc_suspend(struct device *dev)
317{
318 struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
319
320 if (device_may_wakeup(dev))
321 enable_irq_wake(sp_rtc->irq);
322
323 return 0;
324}
325
326static int sp_rtc_resume(struct device *dev)
327{
328 struct sunplus_rtc *sp_rtc = dev_get_drvdata(dev);
329
330 if (device_may_wakeup(dev))
331 disable_irq_wake(sp_rtc->irq);
332
333 return 0;
334}
335#endif
336
337static const struct of_device_id sp_rtc_of_match[] = {
338 { .compatible = "sunplus,sp7021-rtc" },
339 { /* sentinel */ }
340};
341MODULE_DEVICE_TABLE(of, sp_rtc_of_match);
342
343static SIMPLE_DEV_PM_OPS(sp_rtc_pm_ops, sp_rtc_suspend, sp_rtc_resume);
344
345static struct platform_driver sp_rtc_driver = {
346 .probe = sp_rtc_probe,
347 .remove = sp_rtc_remove,
348 .driver = {
349 .name = "sp7021-rtc",
350 .of_match_table = sp_rtc_of_match,
351 .pm = &sp_rtc_pm_ops,
352 },
353};
354module_platform_driver(sp_rtc_driver);
355
356MODULE_AUTHOR("Vincent Shih <[email protected]>");
357MODULE_DESCRIPTION("Sunplus RTC driver");
358MODULE_LICENSE("GPL v2");
359