Merge tag 'rtc-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux

Pull RTC updates from Alexandre Belloni:
 "There is an unusual amount of new drivers this cycle, and this
  explains the number of insertions.

  Other than that, the changes are the usual fixes and feature addition.

  Subsystem updates:
   - new quartz-load-femtofarads DT property for quartz load capacitance
   - remove rtc_class_ops.read_callback

  New drivers:
   - Abracon AB-RTCMC-32.768kHz-EOZ9
   - Amlogic Meson RTC
   - Cadence RTC IP
   - Microcrystal RV3028
   - Whwave sd3078

  Driver updates:
   - cmos: ignore bogus century byte
   - ds1307: rework rx8130 support
   - isl1208: add isl1209 support, nvmem support
   - rs5C372: report invalid time when the oscillator stopped
   - rx8581: add rx8571 support"

* tag 'rtc-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (66 commits)
  rtc: pic32: convert to SPDX identifier
  rtc: pic32: let the core handle range
  rtc: pic32: convert to devm_rtc_allocate_device
  rtc: update my email address
  rtc: rv8803: convert to SPDX identifier
  rtc: rv8803: let the core handle range
  rtc: tx4939: convert to SPDX identifier
  rtc: tx4939: use .set_time
  rtc: tx4939: switch to rtc_time64_to_tm/rtc_tm_to_time64
  rtc: tx4939: set range
  rtc: tx4939: remove useless test
  rtc: zynqmp: let the core handle range
  rtc: zynqmp: fix possible race condition
  rtc: imx-sc: use rtc_time64_to_tm
  rtc: rx8581: Add support for Epson rx8571 RTC
  dt-bindings: rtc: add rx8571 compatible
  rtc: pcf85063: remove dead code
  rtc: remove rtc_class_ops.read_callback
  rtc: add AB-RTCMC-32.768kHz-EOZ9 RTC support
  dt-bindings: rtc: add ABEOZ9
  ...

1 files changed, 407 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-meson.c b/drivers/rtc/rtc-meson.c
new file mode 100644
index 000000000000..e08b981dfc21
--- /dev/null
+++ b/drivers/rtc/rtc-meson.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RTC driver for the interal RTC block in the Amlogic Meson6, Meson8,
+ * Meson8b and Meson8m2 SoCs.
+ *
+ * The RTC is split in to two parts, the AHB front end and a simple serial
+ * connection to the actual registers. This driver manages both parts.
+ *
+ * Copyright (c) 2018 Martin Blumenstingl <martin.blumenstingl@googlemail.com>
+ * Copyright (c) 2015 Ben Dooks <ben.dooks@codethink.co.uk> for Codethink Ltd
+ * Based on origin by Carlo Caione <carlo@endlessm.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/rtc.h>
+
+/* registers accessed from cpu bus */
+#define RTC_ADDR0				0x00
+	#define RTC_ADDR0_LINE_SCLK		BIT(0)
+	#define RTC_ADDR0_LINE_SEN		BIT(1)
+	#define RTC_ADDR0_LINE_SDI		BIT(2)
+	#define RTC_ADDR0_START_SER		BIT(17)
+	#define RTC_ADDR0_WAIT_SER		BIT(22)
+	#define RTC_ADDR0_DATA			GENMASK(31, 24)
+
+#define RTC_ADDR1				0x04
+	#define RTC_ADDR1_SDO			BIT(0)
+	#define RTC_ADDR1_S_READY		BIT(1)
+
+#define RTC_ADDR2				0x08
+#define RTC_ADDR3				0x0c
+
+#define RTC_REG4				0x10
+	#define RTC_REG4_STATIC_VALUE		GENMASK(7, 0)
+
+/* rtc registers accessed via rtc-serial interface */
+#define RTC_COUNTER		(0)
+#define RTC_SEC_ADJ		(2)
+#define RTC_REGMEM_0		(4)
+#define RTC_REGMEM_1		(5)
+#define RTC_REGMEM_2		(6)
+#define RTC_REGMEM_3		(7)
+
+#define RTC_ADDR_BITS		(3)	/* number of address bits to send */
+#define RTC_DATA_BITS		(32)	/* number of data bits to tx/rx */
+
+#define MESON_STATIC_BIAS_CUR	(0x5 << 1)
+#define MESON_STATIC_VOLTAGE	(0x3 << 11)
+#define MESON_STATIC_DEFAULT    (MESON_STATIC_BIAS_CUR | MESON_STATIC_VOLTAGE)
+
+struct meson_rtc {
+	struct rtc_device	*rtc;		/* rtc device we created */
+	struct device		*dev;		/* device we bound from */
+	struct reset_control	*reset;		/* reset source */
+	struct regulator	*vdd;		/* voltage input */
+	struct regmap		*peripheral;	/* peripheral registers */
+	struct regmap		*serial;	/* serial registers */
+};
+
+static const struct regmap_config meson_rtc_peripheral_regmap_config = {
+	.name		= "peripheral-registers",
+	.reg_bits	= 8,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.max_register	= RTC_REG4,
+	.fast_io	= true,
+};
+
+/* RTC front-end serialiser controls */
+
+static void meson_rtc_sclk_pulse(struct meson_rtc *rtc)
+{
+	udelay(5);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SCLK, 0);
+	udelay(5);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SCLK,
+			   RTC_ADDR0_LINE_SCLK);
+}
+
+static void meson_rtc_send_bit(struct meson_rtc *rtc, unsigned int bit)
+{
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI,
+			   bit ? RTC_ADDR0_LINE_SDI : 0);
+	meson_rtc_sclk_pulse(rtc);
+}
+
+static void meson_rtc_send_bits(struct meson_rtc *rtc, u32 data,
+				unsigned int nr)
+{
+	u32 bit = 1 << (nr - 1);
+
+	while (bit) {
+		meson_rtc_send_bit(rtc, data & bit);
+		bit >>= 1;
+	}
+}
+
+static void meson_rtc_set_dir(struct meson_rtc *rtc, u32 mode)
+{
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN, 0);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI, 0);
+	meson_rtc_send_bit(rtc, mode);
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SDI, 0);
+}
+
+static u32 meson_rtc_get_data(struct meson_rtc *rtc)
+{
+	u32 tmp, val = 0;
+	int bit;
+
+	for (bit = 0; bit < RTC_DATA_BITS; bit++) {
+		meson_rtc_sclk_pulse(rtc);
+		val <<= 1;
+
+		regmap_read(rtc->peripheral, RTC_ADDR1, &tmp);
+		val |= tmp & RTC_ADDR1_SDO;
+	}
+
+	return val;
+}
+
+static int meson_rtc_get_bus(struct meson_rtc *rtc)
+{
+	int ret, retries = 3;
+	u32 val;
+
+	/* prepare bus for transfers, set all lines low */
+	val = RTC_ADDR0_LINE_SDI | RTC_ADDR0_LINE_SEN | RTC_ADDR0_LINE_SCLK;
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, val, 0);
+
+	for (retries = 0; retries < 3; retries++) {
+		/* wait for the bus to be ready */
+		if (!regmap_read_poll_timeout(rtc->peripheral, RTC_ADDR1, val,
+					      val & RTC_ADDR1_S_READY, 10,
+					      10000))
+			return 0;
+
+		dev_warn(rtc->dev, "failed to get bus, resetting RTC\n");
+
+		ret = reset_control_reset(rtc->reset);
+		if (ret)
+			return ret;
+	}
+
+	dev_err(rtc->dev, "bus is not ready\n");
+	return -ETIMEDOUT;
+}
+
+static int meson_rtc_serial_bus_reg_read(void *context, unsigned int reg,
+					 unsigned int *data)
+{
+	struct meson_rtc *rtc = context;
+	int ret;
+
+	ret = meson_rtc_get_bus(rtc);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN,
+			   RTC_ADDR0_LINE_SEN);
+	meson_rtc_send_bits(rtc, reg, RTC_ADDR_BITS);
+	meson_rtc_set_dir(rtc, 0);
+	*data = meson_rtc_get_data(rtc);
+
+	return 0;
+}
+
+static int meson_rtc_serial_bus_reg_write(void *context, unsigned int reg,
+					  unsigned int data)
+{
+	struct meson_rtc *rtc = context;
+	int ret;
+
+	ret = meson_rtc_get_bus(rtc);
+	if (ret)
+		return ret;
+
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0, RTC_ADDR0_LINE_SEN,
+			   RTC_ADDR0_LINE_SEN);
+	meson_rtc_send_bits(rtc, data, RTC_DATA_BITS);
+	meson_rtc_send_bits(rtc, reg, RTC_ADDR_BITS);
+	meson_rtc_set_dir(rtc, 1);
+
+	return 0;
+}
+
+static const struct regmap_bus meson_rtc_serial_bus = {
+	.reg_read	= meson_rtc_serial_bus_reg_read,
+	.reg_write	= meson_rtc_serial_bus_reg_write,
+};
+
+static const struct regmap_config meson_rtc_serial_regmap_config = {
+	.name		= "serial-registers",
+	.reg_bits	= 4,
+	.reg_stride	= 1,
+	.val_bits	= 32,
+	.max_register	= RTC_REGMEM_3,
+	.fast_io	= false,
+};
+
+static int meson_rtc_write_static(struct meson_rtc *rtc, u32 data)
+{
+	u32 tmp;
+
+	regmap_write(rtc->peripheral, RTC_REG4,
+		     FIELD_PREP(RTC_REG4_STATIC_VALUE, (data >> 8)));
+
+	/* write the static value and start the auto serializer */
+	tmp = FIELD_PREP(RTC_ADDR0_DATA, (data & 0xff)) | RTC_ADDR0_START_SER;
+	regmap_update_bits(rtc->peripheral, RTC_ADDR0,
+			   RTC_ADDR0_DATA | RTC_ADDR0_START_SER, tmp);
+
+	/* wait for the auto serializer to complete */
+	return regmap_read_poll_timeout(rtc->peripheral, RTC_REG4, tmp,
+					!(tmp & RTC_ADDR0_WAIT_SER), 10,
+					10000);
+}
+
+/* RTC interface layer functions */
+
+static int meson_rtc_gettime(struct device *dev, struct rtc_time *tm)
+{
+	struct meson_rtc *rtc = dev_get_drvdata(dev);
+	u32 time;
+	int ret;
+
+	ret = regmap_read(rtc->serial, RTC_COUNTER, &time);
+	if (!ret)
+		rtc_time64_to_tm(time, tm);
+
+	return ret;
+}
+
+static int meson_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	struct meson_rtc *rtc = dev_get_drvdata(dev);
+
+	return regmap_write(rtc->serial, RTC_COUNTER, rtc_tm_to_time64(tm));
+}
+
+static const struct rtc_class_ops meson_rtc_ops = {
+	.read_time	= meson_rtc_gettime,
+	.set_time	= meson_rtc_settime,
+};
+
+/* NVMEM interface layer functions */
+
+static int meson_rtc_regmem_read(void *context, unsigned int offset,
+				 void *buf, size_t bytes)
+{
+	struct meson_rtc *rtc = context;
+	unsigned int read_offset, read_size;
+
+	read_offset = RTC_REGMEM_0 + (offset / 4);
+	read_size = bytes / 4;
+
+	return regmap_bulk_read(rtc->serial, read_offset, buf, read_size);
+}
+
+static int meson_rtc_regmem_write(void *context, unsigned int offset,
+				  void *buf, size_t bytes)
+{
+	struct meson_rtc *rtc = context;
+	unsigned int write_offset, write_size;
+
+	write_offset = RTC_REGMEM_0 + (offset / 4);
+	write_size = bytes / 4;
+
+	return regmap_bulk_write(rtc->serial, write_offset, buf, write_size);
+}
+
+static int meson_rtc_probe(struct platform_device *pdev)
+{
+	struct nvmem_config meson_rtc_nvmem_config = {
+		.name = "meson-rtc-regmem",
+		.type = NVMEM_TYPE_BATTERY_BACKED,
+		.word_size = 4,
+		.stride = 4,
+		.size = 4 * 4,
+		.reg_read = meson_rtc_regmem_read,
+		.reg_write = meson_rtc_regmem_write,
+	};
+	struct device *dev = &pdev->dev;
+	struct meson_rtc *rtc;
+	struct resource *res;
+	void __iomem *base;
+	int ret;
+	u32 tm;
+
+	rtc = devm_kzalloc(dev, sizeof(struct meson_rtc), GFP_KERNEL);
+	if (!rtc)
+		return -ENOMEM;
+
+	rtc->rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc->rtc))
+		return PTR_ERR(rtc->rtc);
+
+	platform_set_drvdata(pdev, rtc);
+
+	rtc->dev = dev;
+
+	rtc->rtc->ops = &meson_rtc_ops;
+	rtc->rtc->range_max = U32_MAX;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	rtc->peripheral = devm_regmap_init_mmio(dev, base,
+					&meson_rtc_peripheral_regmap_config);
+	if (IS_ERR(rtc->peripheral)) {
+		dev_err(dev, "failed to create peripheral regmap\n");
+		return PTR_ERR(rtc->peripheral);
+	}
+
+	rtc->reset = devm_reset_control_get(dev, NULL);
+	if (IS_ERR(rtc->reset)) {
+		dev_err(dev, "missing reset line\n");
+		return PTR_ERR(rtc->reset);
+	}
+
+	rtc->vdd = devm_regulator_get(dev, "vdd");
+	if (IS_ERR(rtc->vdd)) {
+		dev_err(dev, "failed to get the vdd-supply\n");
+		return PTR_ERR(rtc->vdd);
+	}
+
+	ret = regulator_enable(rtc->vdd);
+	if (ret) {
+		dev_err(dev, "failed to enable vdd-supply\n");
+		return ret;
+	}
+
+	ret = meson_rtc_write_static(rtc, MESON_STATIC_DEFAULT);
+	if (ret) {
+		dev_err(dev, "failed to set static values\n");
+		goto out_disable_vdd;
+	}
+
+	rtc->serial = devm_regmap_init(dev, &meson_rtc_serial_bus, rtc,
+				       &meson_rtc_serial_regmap_config);
+	if (IS_ERR(rtc->serial)) {
+		dev_err(dev, "failed to create serial regmap\n");
+		ret = PTR_ERR(rtc->serial);
+		goto out_disable_vdd;
+	}
+
+	/*
+	 * check if we can read RTC counter, if not then the RTC is probably
+	 * not functional. If it isn't probably best to not bind.
+	 */
+	ret = regmap_read(rtc->serial, RTC_COUNTER, &tm);
+	if (ret) {
+		dev_err(dev, "cannot read RTC counter, RTC not functional\n");
+		goto out_disable_vdd;
+	}
+
+	meson_rtc_nvmem_config.priv = rtc;
+	ret = rtc_nvmem_register(rtc->rtc, &meson_rtc_nvmem_config);
+	if (ret)
+		goto out_disable_vdd;
+
+	ret = rtc_register_device(rtc->rtc);
+	if (ret)
+		goto out_disable_vdd;
+
+	return 0;
+
+out_disable_vdd:
+	regulator_disable(rtc->vdd);
+	return ret;
+}
+
+static const struct of_device_id meson_rtc_dt_match[] = {
+	{ .compatible = "amlogic,meson6-rtc", },
+	{ .compatible = "amlogic,meson8-rtc", },
+	{ .compatible = "amlogic,meson8b-rtc", },
+	{ .compatible = "amlogic,meson8m2-rtc", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, meson_rtc_dt_match);
+
+static struct platform_driver meson_rtc_driver = {
+	.probe		= meson_rtc_probe,
+	.driver		= {
+		.name		= "meson-rtc",
+		.of_match_table	= of_match_ptr(meson_rtc_dt_match),
+	},
+};
+module_platform_driver(meson_rtc_driver);
+
+MODULE_DESCRIPTION("Amlogic Meson RTC Driver");
+MODULE_AUTHOR("Ben Dooks <ben.doosk@codethink.co.uk>");
+MODULE_AUTHOR("Martin Blumenstingl <martin.blumenstingl@googlemail.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:meson-rtc");