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eb7b8585 JB |
1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | // | |
3 | // Copyright 2022 NXP. | |
4 | ||
5 | #include <linux/init.h> | |
6 | #include <linux/io.h> | |
7 | #include <linux/kernel.h> | |
8 | #include <linux/mfd/syscon.h> | |
9 | #include <linux/module.h> | |
10 | #include <linux/of.h> | |
11 | #include <linux/platform_device.h> | |
12 | #include <linux/pm_wakeirq.h> | |
13 | #include <linux/regmap.h> | |
14 | #include <linux/rtc.h> | |
15 | ||
16 | #define BBNSM_CTRL 0x8 | |
17 | #define BBNSM_INT_EN 0x10 | |
18 | #define BBNSM_EVENTS 0x14 | |
19 | #define BBNSM_RTC_LS 0x40 | |
20 | #define BBNSM_RTC_MS 0x44 | |
21 | #define BBNSM_TA 0x50 | |
22 | ||
23 | #define RTC_EN 0x2 | |
24 | #define RTC_EN_MSK 0x3 | |
25 | #define TA_EN (0x2 << 2) | |
26 | #define TA_DIS (0x1 << 2) | |
27 | #define TA_EN_MSK (0x3 << 2) | |
28 | #define RTC_INT_EN 0x2 | |
29 | #define TA_INT_EN (0x2 << 2) | |
30 | ||
31 | #define BBNSM_EVENT_TA (0x2 << 2) | |
32 | ||
33 | #define CNTR_TO_SECS_SH 15 | |
34 | ||
35 | struct bbnsm_rtc { | |
36 | struct rtc_device *rtc; | |
37 | struct regmap *regmap; | |
38 | int irq; | |
39 | struct clk *clk; | |
40 | }; | |
41 | ||
42 | static u32 bbnsm_read_counter(struct bbnsm_rtc *bbnsm) | |
43 | { | |
44 | u32 rtc_msb, rtc_lsb; | |
45 | unsigned int timeout = 100; | |
46 | u32 time; | |
47 | u32 tmp = 0; | |
48 | ||
49 | do { | |
50 | time = tmp; | |
51 | /* read the msb */ | |
52 | regmap_read(bbnsm->regmap, BBNSM_RTC_MS, &rtc_msb); | |
53 | /* read the lsb */ | |
54 | regmap_read(bbnsm->regmap, BBNSM_RTC_LS, &rtc_lsb); | |
55 | /* convert to seconds */ | |
56 | tmp = (rtc_msb << 17) | (rtc_lsb >> 15); | |
57 | } while (tmp != time && --timeout); | |
58 | ||
59 | return time; | |
60 | } | |
61 | ||
62 | static int bbnsm_rtc_read_time(struct device *dev, struct rtc_time *tm) | |
63 | { | |
64 | struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); | |
65 | unsigned long time; | |
66 | u32 val; | |
67 | ||
68 | regmap_read(bbnsm->regmap, BBNSM_CTRL, &val); | |
69 | if ((val & RTC_EN_MSK) != RTC_EN) | |
70 | return -EINVAL; | |
71 | ||
72 | time = bbnsm_read_counter(bbnsm); | |
73 | rtc_time64_to_tm(time, tm); | |
74 | ||
75 | return 0; | |
76 | } | |
77 | ||
78 | static int bbnsm_rtc_set_time(struct device *dev, struct rtc_time *tm) | |
79 | { | |
80 | struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); | |
81 | unsigned long time = rtc_tm_to_time64(tm); | |
82 | ||
83 | /* disable the RTC first */ | |
84 | regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, 0); | |
85 | ||
86 | /* write the 32bit sec time to 47 bit timer counter, leaving 15 LSBs blank */ | |
87 | regmap_write(bbnsm->regmap, BBNSM_RTC_LS, time << CNTR_TO_SECS_SH); | |
88 | regmap_write(bbnsm->regmap, BBNSM_RTC_MS, time >> (32 - CNTR_TO_SECS_SH)); | |
89 | ||
90 | /* Enable the RTC again */ | |
91 | regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, RTC_EN_MSK, RTC_EN); | |
92 | ||
93 | return 0; | |
94 | } | |
95 | ||
96 | static int bbnsm_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) | |
97 | { | |
98 | struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); | |
99 | u32 bbnsm_events, bbnsm_ta; | |
100 | ||
101 | regmap_read(bbnsm->regmap, BBNSM_TA, &bbnsm_ta); | |
102 | rtc_time64_to_tm(bbnsm_ta, &alrm->time); | |
103 | ||
104 | regmap_read(bbnsm->regmap, BBNSM_EVENTS, &bbnsm_events); | |
105 | alrm->pending = (bbnsm_events & BBNSM_EVENT_TA) ? 1 : 0; | |
106 | ||
107 | return 0; | |
108 | } | |
109 | ||
110 | static int bbnsm_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) | |
111 | { | |
112 | struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); | |
113 | ||
114 | /* enable the alarm event */ | |
115 | regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN_MSK, enable ? TA_EN : TA_DIS); | |
116 | /* enable the alarm interrupt */ | |
117 | regmap_update_bits(bbnsm->regmap, BBNSM_INT_EN, TA_EN_MSK, enable ? TA_EN : TA_DIS); | |
118 | ||
119 | return 0; | |
120 | } | |
121 | ||
122 | static int bbnsm_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) | |
123 | { | |
124 | struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); | |
125 | unsigned long time = rtc_tm_to_time64(&alrm->time); | |
126 | ||
127 | /* disable the alarm */ | |
128 | regmap_update_bits(bbnsm->regmap, BBNSM_CTRL, TA_EN, TA_EN); | |
129 | ||
130 | /* write the seconds to TA */ | |
131 | regmap_write(bbnsm->regmap, BBNSM_TA, time); | |
132 | ||
133 | return bbnsm_rtc_alarm_irq_enable(dev, alrm->enabled); | |
134 | } | |
135 | ||
136 | static const struct rtc_class_ops bbnsm_rtc_ops = { | |
137 | .read_time = bbnsm_rtc_read_time, | |
138 | .set_time = bbnsm_rtc_set_time, | |
139 | .read_alarm = bbnsm_rtc_read_alarm, | |
140 | .set_alarm = bbnsm_rtc_set_alarm, | |
141 | .alarm_irq_enable = bbnsm_rtc_alarm_irq_enable, | |
142 | }; | |
143 | ||
144 | static irqreturn_t bbnsm_rtc_irq_handler(int irq, void *dev_id) | |
145 | { | |
146 | struct device *dev = dev_id; | |
147 | struct bbnsm_rtc *bbnsm = dev_get_drvdata(dev); | |
148 | u32 val; | |
149 | ||
150 | regmap_read(bbnsm->regmap, BBNSM_EVENTS, &val); | |
151 | if (val & BBNSM_EVENT_TA) { | |
152 | bbnsm_rtc_alarm_irq_enable(dev, false); | |
153 | /* clear the alarm event */ | |
154 | regmap_write_bits(bbnsm->regmap, BBNSM_EVENTS, TA_EN_MSK, BBNSM_EVENT_TA); | |
155 | rtc_update_irq(bbnsm->rtc, 1, RTC_AF | RTC_IRQF); | |
156 | ||
157 | return IRQ_HANDLED; | |
158 | } | |
159 | ||
160 | return IRQ_NONE; | |
161 | } | |
162 | ||
163 | static int bbnsm_rtc_probe(struct platform_device *pdev) | |
164 | { | |
165 | struct device_node *np = pdev->dev.of_node; | |
166 | struct bbnsm_rtc *bbnsm; | |
167 | int ret; | |
168 | ||
169 | bbnsm = devm_kzalloc(&pdev->dev, sizeof(*bbnsm), GFP_KERNEL); | |
170 | if (!bbnsm) | |
171 | return -ENOMEM; | |
172 | ||
173 | bbnsm->rtc = devm_rtc_allocate_device(&pdev->dev); | |
174 | if (IS_ERR(bbnsm->rtc)) | |
175 | return PTR_ERR(bbnsm->rtc); | |
176 | ||
177 | bbnsm->regmap = syscon_node_to_regmap(np->parent); | |
178 | if (IS_ERR(bbnsm->regmap)) { | |
179 | dev_dbg(&pdev->dev, "bbnsm get regmap failed\n"); | |
180 | return PTR_ERR(bbnsm->regmap); | |
181 | } | |
182 | ||
183 | bbnsm->irq = platform_get_irq(pdev, 0); | |
184 | if (bbnsm->irq < 0) | |
185 | return bbnsm->irq; | |
186 | ||
187 | platform_set_drvdata(pdev, bbnsm); | |
188 | ||
189 | /* clear all the pending events */ | |
190 | regmap_write(bbnsm->regmap, BBNSM_EVENTS, 0x7A); | |
191 | ||
192 | device_init_wakeup(&pdev->dev, true); | |
193 | dev_pm_set_wake_irq(&pdev->dev, bbnsm->irq); | |
194 | ||
195 | ret = devm_request_irq(&pdev->dev, bbnsm->irq, bbnsm_rtc_irq_handler, | |
196 | IRQF_SHARED, "rtc alarm", &pdev->dev); | |
197 | if (ret) { | |
198 | dev_err(&pdev->dev, "failed to request irq %d: %d\n", | |
199 | bbnsm->irq, ret); | |
200 | return ret; | |
201 | } | |
202 | ||
203 | bbnsm->rtc->ops = &bbnsm_rtc_ops; | |
204 | bbnsm->rtc->range_max = U32_MAX; | |
205 | ||
206 | return devm_rtc_register_device(bbnsm->rtc); | |
207 | } | |
208 | ||
209 | static const struct of_device_id bbnsm_dt_ids[] = { | |
210 | { .compatible = "nxp,imx93-bbnsm-rtc" }, | |
211 | { /* sentinel */ }, | |
212 | }; | |
213 | MODULE_DEVICE_TABLE(of, bbnsm_dt_ids); | |
214 | ||
215 | static struct platform_driver bbnsm_rtc_driver = { | |
216 | .driver = { | |
217 | .name = "bbnsm_rtc", | |
218 | .of_match_table = bbnsm_dt_ids, | |
219 | }, | |
220 | .probe = bbnsm_rtc_probe, | |
221 | }; | |
222 | module_platform_driver(bbnsm_rtc_driver); | |
223 | ||
224 | MODULE_AUTHOR("Jacky Bai <ping.bai@nxp.com>"); | |
225 | MODULE_DESCRIPTION("NXP BBNSM RTC Driver"); | |
226 | MODULE_LICENSE("GPL"); |