309 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * MOXA ART RTC driver.4 *5 * Copyright (C) 2013 Jonas Jensen6 *7 * Jonas Jensen <jonas.jensen@gmail.com>8 *9 * Based on code from10 * Moxa Technology Co., Ltd. <www.moxa.com>11 */12 13#include <linux/err.h>14#include <linux/init.h>15#include <linux/kernel.h>16#include <linux/delay.h>17#include <linux/rtc.h>18#include <linux/platform_device.h>19#include <linux/module.h>20#include <linux/mod_devicetable.h>21#include <linux/gpio/consumer.h>22 23#define GPIO_RTC_RESERVED 0x0C24#define GPIO_RTC_DATA_SET 0x1025#define GPIO_RTC_DATA_CLEAR 0x1426#define GPIO_RTC_PIN_PULL_ENABLE 0x1827#define GPIO_RTC_PIN_PULL_TYPE 0x1C28#define GPIO_RTC_INT_ENABLE 0x2029#define GPIO_RTC_INT_RAW_STATE 0x2430#define GPIO_RTC_INT_MASKED_STATE 0x2831#define GPIO_RTC_INT_MASK 0x2C32#define GPIO_RTC_INT_CLEAR 0x3033#define GPIO_RTC_INT_TRIGGER 0x3434#define GPIO_RTC_INT_BOTH 0x3835#define GPIO_RTC_INT_RISE_NEG 0x3C36#define GPIO_RTC_BOUNCE_ENABLE 0x4037#define GPIO_RTC_BOUNCE_PRE_SCALE 0x4438#define GPIO_RTC_PROTECT_W 0x8E39#define GPIO_RTC_PROTECT_R 0x8F40#define GPIO_RTC_YEAR_W 0x8C41#define GPIO_RTC_YEAR_R 0x8D42#define GPIO_RTC_DAY_W 0x8A43#define GPIO_RTC_DAY_R 0x8B44#define GPIO_RTC_MONTH_W 0x8845#define GPIO_RTC_MONTH_R 0x8946#define GPIO_RTC_DATE_W 0x8647#define GPIO_RTC_DATE_R 0x8748#define GPIO_RTC_HOURS_W 0x8449#define GPIO_RTC_HOURS_R 0x8550#define GPIO_RTC_MINUTES_W 0x8251#define GPIO_RTC_MINUTES_R 0x8352#define GPIO_RTC_SECONDS_W 0x8053#define GPIO_RTC_SECONDS_R 0x8154#define GPIO_RTC_DELAY_TIME 855 56struct moxart_rtc {57 struct rtc_device *rtc;58 spinlock_t rtc_lock;59 struct gpio_desc *gpio_data;60 struct gpio_desc *gpio_sclk;61 struct gpio_desc *gpio_reset;62};63 64static int day_of_year[12] = { 0, 31, 59, 90, 120, 151, 181,65 212, 243, 273, 304, 334 };66 67static void moxart_rtc_write_byte(struct device *dev, u8 data)68{69 struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);70 int i;71 72 for (i = 0; i < 8; i++, data >>= 1) {73 gpiod_set_value(moxart_rtc->gpio_sclk, 0);74 gpiod_set_value(moxart_rtc->gpio_data, ((data & 1) == 1));75 udelay(GPIO_RTC_DELAY_TIME);76 gpiod_set_value(moxart_rtc->gpio_sclk, 1);77 udelay(GPIO_RTC_DELAY_TIME);78 }79}80 81static u8 moxart_rtc_read_byte(struct device *dev)82{83 struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);84 int i;85 u8 data = 0;86 87 for (i = 0; i < 8; i++) {88 gpiod_set_value(moxart_rtc->gpio_sclk, 0);89 udelay(GPIO_RTC_DELAY_TIME);90 gpiod_set_value(moxart_rtc->gpio_sclk, 1);91 udelay(GPIO_RTC_DELAY_TIME);92 if (gpiod_get_value(moxart_rtc->gpio_data))93 data |= (1 << i);94 udelay(GPIO_RTC_DELAY_TIME);95 }96 return data;97}98 99static u8 moxart_rtc_read_register(struct device *dev, u8 cmd)100{101 struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);102 u8 data;103 unsigned long flags;104 105 local_irq_save(flags);106 107 gpiod_direction_output(moxart_rtc->gpio_data, 0);108 gpiod_set_value(moxart_rtc->gpio_reset, 1);109 udelay(GPIO_RTC_DELAY_TIME);110 moxart_rtc_write_byte(dev, cmd);111 gpiod_direction_input(moxart_rtc->gpio_data);112 udelay(GPIO_RTC_DELAY_TIME);113 data = moxart_rtc_read_byte(dev);114 gpiod_set_value(moxart_rtc->gpio_sclk, 0);115 gpiod_set_value(moxart_rtc->gpio_reset, 0);116 udelay(GPIO_RTC_DELAY_TIME);117 118 local_irq_restore(flags);119 120 return data;121}122 123static void moxart_rtc_write_register(struct device *dev, u8 cmd, u8 data)124{125 struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);126 unsigned long flags;127 128 local_irq_save(flags);129 130 gpiod_direction_output(moxart_rtc->gpio_data, 0);131 gpiod_set_value(moxart_rtc->gpio_reset, 1);132 udelay(GPIO_RTC_DELAY_TIME);133 moxart_rtc_write_byte(dev, cmd);134 moxart_rtc_write_byte(dev, data);135 gpiod_set_value(moxart_rtc->gpio_sclk, 0);136 gpiod_set_value(moxart_rtc->gpio_reset, 0);137 udelay(GPIO_RTC_DELAY_TIME);138 139 local_irq_restore(flags);140}141 142static int moxart_rtc_set_time(struct device *dev, struct rtc_time *tm)143{144 struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);145 146 spin_lock_irq(&moxart_rtc->rtc_lock);147 148 moxart_rtc_write_register(dev, GPIO_RTC_PROTECT_W, 0);149 moxart_rtc_write_register(dev, GPIO_RTC_YEAR_W,150 (((tm->tm_year - 100) / 10) << 4) |151 ((tm->tm_year - 100) % 10));152 153 moxart_rtc_write_register(dev, GPIO_RTC_MONTH_W,154 (((tm->tm_mon + 1) / 10) << 4) |155 ((tm->tm_mon + 1) % 10));156 157 moxart_rtc_write_register(dev, GPIO_RTC_DATE_W,158 ((tm->tm_mday / 10) << 4) |159 (tm->tm_mday % 10));160 161 moxart_rtc_write_register(dev, GPIO_RTC_HOURS_W,162 ((tm->tm_hour / 10) << 4) |163 (tm->tm_hour % 10));164 165 moxart_rtc_write_register(dev, GPIO_RTC_MINUTES_W,166 ((tm->tm_min / 10) << 4) |167 (tm->tm_min % 10));168 169 moxart_rtc_write_register(dev, GPIO_RTC_SECONDS_W,170 ((tm->tm_sec / 10) << 4) |171 (tm->tm_sec % 10));172 173 moxart_rtc_write_register(dev, GPIO_RTC_PROTECT_W, 0x80);174 175 spin_unlock_irq(&moxart_rtc->rtc_lock);176 177 dev_dbg(dev, "%s: success tm_year=%d tm_mon=%d\n"178 "tm_mday=%d tm_hour=%d tm_min=%d tm_sec=%d\n",179 __func__, tm->tm_year, tm->tm_mon, tm->tm_mday,180 tm->tm_hour, tm->tm_min, tm->tm_sec);181 182 return 0;183}184 185static int moxart_rtc_read_time(struct device *dev, struct rtc_time *tm)186{187 struct moxart_rtc *moxart_rtc = dev_get_drvdata(dev);188 unsigned char v;189 190 spin_lock_irq(&moxart_rtc->rtc_lock);191 192 v = moxart_rtc_read_register(dev, GPIO_RTC_SECONDS_R);193 tm->tm_sec = (((v & 0x70) >> 4) * 10) + (v & 0x0F);194 195 v = moxart_rtc_read_register(dev, GPIO_RTC_MINUTES_R);196 tm->tm_min = (((v & 0x70) >> 4) * 10) + (v & 0x0F);197 198 v = moxart_rtc_read_register(dev, GPIO_RTC_HOURS_R);199 if (v & 0x80) { /* 12-hour mode */200 tm->tm_hour = (((v & 0x10) >> 4) * 10) + (v & 0x0F);201 if (v & 0x20) { /* PM mode */202 tm->tm_hour += 12;203 if (tm->tm_hour >= 24)204 tm->tm_hour = 0;205 }206 } else { /* 24-hour mode */207 tm->tm_hour = (((v & 0x30) >> 4) * 10) + (v & 0x0F);208 }209 210 v = moxart_rtc_read_register(dev, GPIO_RTC_DATE_R);211 tm->tm_mday = (((v & 0x30) >> 4) * 10) + (v & 0x0F);212 213 v = moxart_rtc_read_register(dev, GPIO_RTC_MONTH_R);214 tm->tm_mon = (((v & 0x10) >> 4) * 10) + (v & 0x0F);215 tm->tm_mon--;216 217 v = moxart_rtc_read_register(dev, GPIO_RTC_YEAR_R);218 tm->tm_year = (((v & 0xF0) >> 4) * 10) + (v & 0x0F);219 tm->tm_year += 100;220 if (tm->tm_year <= 69)221 tm->tm_year += 100;222 223 v = moxart_rtc_read_register(dev, GPIO_RTC_DAY_R);224 tm->tm_wday = (v & 0x0f) - 1;225 tm->tm_yday = day_of_year[tm->tm_mon];226 tm->tm_yday += (tm->tm_mday - 1);227 if (tm->tm_mon >= 2) {228 if (!(tm->tm_year % 4) && (tm->tm_year % 100))229 tm->tm_yday++;230 }231 232 tm->tm_isdst = 0;233 234 spin_unlock_irq(&moxart_rtc->rtc_lock);235 236 return 0;237}238 239static const struct rtc_class_ops moxart_rtc_ops = {240 .read_time = moxart_rtc_read_time,241 .set_time = moxart_rtc_set_time,242};243 244static int moxart_rtc_probe(struct platform_device *pdev)245{246 struct moxart_rtc *moxart_rtc;247 int ret = 0;248 249 moxart_rtc = devm_kzalloc(&pdev->dev, sizeof(*moxart_rtc), GFP_KERNEL);250 if (!moxart_rtc)251 return -ENOMEM;252 253 moxart_rtc->gpio_data = devm_gpiod_get(&pdev->dev, "rtc-data",254 GPIOD_IN);255 ret = PTR_ERR_OR_ZERO(moxart_rtc->gpio_data);256 if (ret) {257 dev_err(&pdev->dev, "can't get rtc data gpio: %d\n", ret);258 return ret;259 }260 261 moxart_rtc->gpio_sclk = devm_gpiod_get(&pdev->dev, "rtc-sclk",262 GPIOD_ASIS);263 ret = PTR_ERR_OR_ZERO(moxart_rtc->gpio_sclk);264 if (ret) {265 dev_err(&pdev->dev, "can't get rtc sclk gpio: %d\n", ret);266 return ret;267 }268 269 moxart_rtc->gpio_reset = devm_gpiod_get(&pdev->dev, "rtc-reset",270 GPIOD_ASIS);271 ret = PTR_ERR_OR_ZERO(moxart_rtc->gpio_reset);272 if (ret) {273 dev_err(&pdev->dev, "can't get rtc reset gpio: %d\n", ret);274 return ret;275 }276 277 spin_lock_init(&moxart_rtc->rtc_lock);278 platform_set_drvdata(pdev, moxart_rtc);279 280 moxart_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,281 &moxart_rtc_ops,282 THIS_MODULE);283 if (IS_ERR(moxart_rtc->rtc)) {284 dev_err(&pdev->dev, "devm_rtc_device_register failed\n");285 return PTR_ERR(moxart_rtc->rtc);286 }287 288 return 0;289}290 291static const struct of_device_id moxart_rtc_match[] = {292 { .compatible = "moxa,moxart-rtc" },293 { },294};295MODULE_DEVICE_TABLE(of, moxart_rtc_match);296 297static struct platform_driver moxart_rtc_driver = {298 .probe = moxart_rtc_probe,299 .driver = {300 .name = "moxart-rtc",301 .of_match_table = moxart_rtc_match,302 },303};304module_platform_driver(moxart_rtc_driver);305 306MODULE_DESCRIPTION("MOXART RTC driver");307MODULE_LICENSE("GPL");308MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");309