3  * RTC driver for the interal RTC block in the Amlogic Meson6, Meson8,
6  * The RTC is split in to two parts, the AHB front end and a simple serial
25 #include <linux/rtc.h>
46 /* rtc registers accessed via rtc-serial interface */
62 	struct rtc_device	*rtc;		/* rtc device we created */  member
79 /* RTC front-end serialiser controls */
81 static void meson_rtc_sclk_pulse(struct meson_rtc *rtc)  in meson_rtc_sclk_pulse()  argument
84 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SCLK, 0);  in meson_rtc_sclk_pulse()
86 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SCLK,  in meson_rtc_sclk_pulse()
90 static void meson_rtc_send_bit(struct meson_rtc *rtc, unsigned int bit)  in meson_rtc_send_bit()  argument
92 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI,  in meson_rtc_send_bit()
94 	meson_rtc_sclk_pulse(rtc);  in meson_rtc_send_bit()
97 static void meson_rtc_send_bits(struct meson_rtc *rtc, u32 data,  in meson_rtc_send_bits()  argument
103 		meson_rtc_send_bit(rtc, data & bit);  in meson_rtc_send_bits()
108 static void meson_rtc_set_dir(struct meson_rtc *rtc, u32 mode)  in meson_rtc_set_dir()  argument
110 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN, 0);  in meson_rtc_set_dir()
111 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI, 0);  in meson_rtc_set_dir()
112 	meson_rtc_send_bit(rtc, mode);  in meson_rtc_set_dir()
113 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI, 0);  in meson_rtc_set_dir()
116 static u32 meson_rtc_get_data(struct meson_rtc *rtc)  in meson_rtc_get_data()  argument
122 		meson_rtc_sclk_pulse(rtc);  in meson_rtc_get_data()
125 		regmap_read(rtc->peripheral, RTC_ADDR1, &tmp);  in meson_rtc_get_data()
132 static int meson_rtc_get_bus(struct meson_rtc *rtc)  in meson_rtc_get_bus()  argument
139 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, val, 0);  in meson_rtc_get_bus()
143 		if (!regmap_read_poll_timeout(rtc->peripheral, RTC_ADDR1, val,  in meson_rtc_get_bus()
148 		dev_warn(rtc->dev, "failed to get bus, resetting RTC\n");  in meson_rtc_get_bus()
150 		ret = reset_control_reset(rtc->reset);  in meson_rtc_get_bus()
155 	dev_err(rtc->dev, "bus is not ready\n");  in meson_rtc_get_bus()
162 	struct meson_rtc *rtc = context;  in meson_rtc_serial_bus_reg_read()  local
165 	ret = meson_rtc_get_bus(rtc);  in meson_rtc_serial_bus_reg_read()
169 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN,  in meson_rtc_serial_bus_reg_read()
171 	meson_rtc_send_bits(rtc, reg, RTC_ADDR_BITS);  in meson_rtc_serial_bus_reg_read()
172 	meson_rtc_set_dir(rtc, 0);  in meson_rtc_serial_bus_reg_read()
173 	*data = meson_rtc_get_data(rtc);  in meson_rtc_serial_bus_reg_read()
181 	struct meson_rtc *rtc = context;  in meson_rtc_serial_bus_reg_write()  local
184 	ret = meson_rtc_get_bus(rtc);  in meson_rtc_serial_bus_reg_write()
188 	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN,  in meson_rtc_serial_bus_reg_write()
190 	meson_rtc_send_bits(rtc, data, RTC_DATA_BITS);  in meson_rtc_serial_bus_reg_write()
191 	meson_rtc_send_bits(rtc, reg, RTC_ADDR_BITS);  in meson_rtc_serial_bus_reg_write()
192 	meson_rtc_set_dir(rtc, 1);  in meson_rtc_serial_bus_reg_write()
211 static int meson_rtc_write_static(struct meson_rtc *rtc, u32 data)  in meson_rtc_write_static()  argument
215 	regmap_write(rtc->peripheral, RTC_REG4,  in meson_rtc_write_static()
220 	regmap_update_bits(rtc->peripheral, RTC_ADDR0,  in meson_rtc_write_static()
224 	return regmap_read_poll_timeout(rtc->peripheral, RTC_REG4, tmp,  in meson_rtc_write_static()
229 /* RTC interface layer functions */
233 	struct meson_rtc *rtc = dev_get_drvdata(dev);  in meson_rtc_gettime()  local
237 	ret = regmap_read(rtc->serial, RTC_COUNTER, &time);  in meson_rtc_gettime()
246 	struct meson_rtc *rtc = dev_get_drvdata(dev);  in meson_rtc_settime()  local
248 	return regmap_write(rtc->serial, RTC_COUNTER, rtc_tm_to_time64(tm));  in meson_rtc_settime()
261 	struct meson_rtc *rtc = context;  in meson_rtc_regmem_read()  local
267 	return regmap_bulk_read(rtc->serial, read_offset, buf, read_size);  in meson_rtc_regmem_read()
273 	struct meson_rtc *rtc = context;  in meson_rtc_regmem_write()  local
279 	return regmap_bulk_write(rtc->serial, write_offset, buf, write_size);  in meson_rtc_regmem_write()
285 		.name = "meson-rtc-regmem",  in meson_rtc_probe()
294 	struct meson_rtc *rtc;  in meson_rtc_probe()  local
299 	rtc = devm_kzalloc(dev, sizeof(struct meson_rtc), GFP_KERNEL);  in meson_rtc_probe()
300 	if (!rtc)  in meson_rtc_probe()
303 	rtc->rtc = devm_rtc_allocate_device(dev);  in meson_rtc_probe()
304 	if (IS_ERR(rtc->rtc))  in meson_rtc_probe()
305 		return PTR_ERR(rtc->rtc);  in meson_rtc_probe()
307 	platform_set_drvdata(pdev, rtc);  in meson_rtc_probe()
309 	rtc->dev = dev;  in meson_rtc_probe()
311 	rtc->rtc->ops = &meson_rtc_ops;  in meson_rtc_probe()
312 	rtc->rtc->range_max = U32_MAX;  in meson_rtc_probe()
318 	rtc->peripheral = devm_regmap_init_mmio(dev, base,  in meson_rtc_probe()
320 	if (IS_ERR(rtc->peripheral)) {  in meson_rtc_probe()
322 		return PTR_ERR(rtc->peripheral);  in meson_rtc_probe()
325 	rtc->reset = devm_reset_control_get(dev, NULL);  in meson_rtc_probe()
326 	if (IS_ERR(rtc->reset)) {  in meson_rtc_probe()
328 		return PTR_ERR(rtc->reset);  in meson_rtc_probe()
331 	rtc->vdd = devm_regulator_get(dev, "vdd");  in meson_rtc_probe()
332 	if (IS_ERR(rtc->vdd)) {  in meson_rtc_probe()
334 		return PTR_ERR(rtc->vdd);  in meson_rtc_probe()
337 	ret = regulator_enable(rtc->vdd);  in meson_rtc_probe()
343 	ret = meson_rtc_write_static(rtc, MESON_STATIC_DEFAULT);  in meson_rtc_probe()
349 	rtc->serial = devm_regmap_init(dev, &meson_rtc_serial_bus, rtc,  in meson_rtc_probe()
351 	if (IS_ERR(rtc->serial)) {  in meson_rtc_probe()
353 		ret = PTR_ERR(rtc->serial);  in meson_rtc_probe()
358 	 * check if we can read RTC counter, if not then the RTC is probably  in meson_rtc_probe()
361 	ret = regmap_read(rtc->serial, RTC_COUNTER, &tm);  in meson_rtc_probe()
363 		dev_err(dev, "cannot read RTC counter, RTC not functional\n");  in meson_rtc_probe()
367 	meson_rtc_nvmem_config.priv = rtc;  in meson_rtc_probe()
368 	ret = devm_rtc_nvmem_register(rtc->rtc, &meson_rtc_nvmem_config);  in meson_rtc_probe()
372 	ret = devm_rtc_register_device(rtc->rtc);  in meson_rtc_probe()
379 	regulator_disable(rtc->vdd);  in meson_rtc_probe()
384 	{ .compatible = "amlogic,meson6-rtc", },
385 	{ .compatible = "amlogic,meson8-rtc", },
386 	{ .compatible = "amlogic,meson8b-rtc", },
387 	{ .compatible = "amlogic,meson8m2-rtc", },
395 		.name		= "meson-rtc",
401 MODULE_DESCRIPTION("Amlogic Meson RTC Driver");
405 MODULE_ALIAS("platform:meson-rtc");