Merge branch 'next' (accumulated 3.16 merge window patches) into master

Now that 3.15 is released, this merges the 'next' branch into 'master',
bringing us to the normal situation where my 'master' branch is the
merge window.

* accumulated work in next: (6809 commits)
  ufs: sb mutex merge + mutex_destroy
  powerpc: update comments for generic idle conversion
  cris: update comments for generic idle conversion
  idle: remove cpu_idle() forward declarations
  nbd: zero from and len fields in NBD_CMD_DISCONNECT.
  mm: convert some level-less printks to pr_*
  MAINTAINERS: adi-buildroot-devel is moderated
  MAINTAINERS: add linux-api for review of API/ABI changes
  mm/kmemleak-test.c: use pr_fmt for logging
  fs/dlm/debug_fs.c: replace seq_printf by seq_puts
  fs/dlm/lockspace.c: convert simple_str to kstr
  fs/dlm/config.c: convert simple_str to kstr
  mm: mark remap_file_pages() syscall as deprecated
  mm: memcontrol: remove unnecessary memcg argument from soft limit functions
  mm: memcontrol: clean up memcg zoneinfo lookup
  mm/memblock.c: call kmemleak directly from memblock_(alloc|free)
  mm/mempool.c: update the kmemleak stack trace for mempool allocations
  lib/radix-tree.c: update the kmemleak stack trace for radix tree allocations
  mm: introduce kmemleak_update_trace()
  mm/kmemleak.c: use %u to print ->checksum
  ...

1 files changed, 199 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-mcp795.c b/drivers/rtc/rtc-mcp795.c
new file mode 100644
index 00000000000..34295bf0041
--- /dev/null
+++ b/drivers/rtc/rtc-mcp795.c
@@ -0,0 +1,199 @@
+/*
+ * SPI Driver for Microchip MCP795 RTC
+ *
+ * Copyright (C) Josef Gajdusek <atx@atx.name>
+ *
+ * based on other Linux RTC drivers
+ *
+ * Device datasheet:
+ * http://ww1.microchip.com/downloads/en/DeviceDoc/22280A.pdf
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/printk.h>
+#include <linux/spi/spi.h>
+#include <linux/rtc.h>
+
+/* MCP795 Instructions, see datasheet table 3-1 */
+#define MCP795_EEREAD	0x03
+#define MCP795_EEWRITE	0x02
+#define MCP795_EEWRDI	0x04
+#define MCP795_EEWREN	0x06
+#define MCP795_SRREAD	0x05
+#define MCP795_SRWRITE	0x01
+#define MCP795_READ		0x13
+#define MCP795_WRITE	0x12
+#define MCP795_UNLOCK	0x14
+#define MCP795_IDWRITE	0x32
+#define MCP795_IDREAD	0x33
+#define MCP795_CLRWDT	0x44
+#define MCP795_CLRRAM	0x54
+
+#define MCP795_ST_BIT	0x80
+#define MCP795_24_BIT	0x40
+
+static int mcp795_rtcc_read(struct device *dev, u8 addr, u8 *buf, u8 count)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	int ret;
+	u8 tx[2];
+
+	tx[0] = MCP795_READ;
+	tx[1] = addr;
+	ret = spi_write_then_read(spi, tx, sizeof(tx), buf, count);
+
+	if (ret)
+		dev_err(dev, "Failed reading %d bytes from address %x.\n",
+					count, addr);
+
+	return ret;
+}
+
+static int mcp795_rtcc_write(struct device *dev, u8 addr, u8 *data, u8 count)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	int ret;
+	u8 tx[2 + count];
+
+	tx[0] = MCP795_WRITE;
+	tx[1] = addr;
+	memcpy(&tx[2], data, count);
+
+	ret = spi_write(spi, tx, 2 + count);
+
+	if (ret)
+		dev_err(dev, "Failed to write %d bytes to address %x.\n",
+					count, addr);
+
+	return ret;
+}
+
+static int mcp795_rtcc_set_bits(struct device *dev, u8 addr, u8 mask, u8 state)
+{
+	int ret;
+	u8 tmp;
+
+	ret = mcp795_rtcc_read(dev, addr, &tmp, 1);
+	if (ret)
+		return ret;
+
+	if ((tmp & mask) != state) {
+		tmp = (tmp & ~mask) | state;
+		ret = mcp795_rtcc_write(dev, addr, &tmp, 1);
+	}
+
+	return ret;
+}
+
+static int mcp795_set_time(struct device *dev, struct rtc_time *tim)
+{
+	int ret;
+	u8 data[7];
+
+	/* Read first, so we can leave config bits untouched */
+	ret = mcp795_rtcc_read(dev, 0x01, data, sizeof(data));
+
+	if (ret)
+		return ret;
+
+	data[0] = (data[0] & 0x80) | ((tim->tm_sec / 10) << 4) | (tim->tm_sec % 10);
+	data[1] = (data[1] & 0x80) | ((tim->tm_min / 10) << 4) | (tim->tm_min % 10);
+	data[2] = ((tim->tm_hour / 10) << 4) | (tim->tm_hour % 10);
+	data[4] = ((tim->tm_mday / 10) << 4) | ((tim->tm_mday) % 10);
+	data[5] = (data[5] & 0x10) | (tim->tm_mon / 10) | (tim->tm_mon % 10);
+
+	if (tim->tm_year > 100)
+		tim->tm_year -= 100;
+
+	data[6] = ((tim->tm_year / 10) << 4) | (tim->tm_year % 10);
+
+	ret = mcp795_rtcc_write(dev, 0x01, data, sizeof(data));
+
+	if (ret)
+		return ret;
+
+	dev_dbg(dev, "Set mcp795: %04d-%02d-%02d %02d:%02d:%02d\n",
+			tim->tm_year + 1900, tim->tm_mon, tim->tm_mday,
+			tim->tm_hour, tim->tm_min, tim->tm_sec);
+
+	return 0;
+}
+
+static int mcp795_read_time(struct device *dev, struct rtc_time *tim)
+{
+	int ret;
+	u8 data[7];
+
+	ret = mcp795_rtcc_read(dev, 0x01, data, sizeof(data));
+
+	if (ret)
+		return ret;
+
+	tim->tm_sec		= ((data[0] & 0x70) >> 4) * 10 + (data[0] & 0x0f);
+	tim->tm_min		= ((data[1] & 0x70) >> 4) * 10 + (data[1] & 0x0f);
+	tim->tm_hour	= ((data[2] & 0x30) >> 4) * 10 + (data[2] & 0x0f);
+	tim->tm_mday	= ((data[4] & 0x30) >> 4) * 10 + (data[4] & 0x0f);
+	tim->tm_mon		= ((data[5] & 0x10) >> 4) * 10 + (data[5] & 0x0f);
+	tim->tm_year	= ((data[6] & 0xf0) >> 4) * 10 + (data[6] & 0x0f) + 100; /* Assume we are in 20xx */
+
+	dev_dbg(dev, "Read from mcp795: %04d-%02d-%02d %02d:%02d:%02d\n",
+				tim->tm_year + 1900, tim->tm_mon, tim->tm_mday,
+				tim->tm_hour, tim->tm_min, tim->tm_sec);
+
+	return rtc_valid_tm(tim);
+}
+
+static struct rtc_class_ops mcp795_rtc_ops = {
+		.read_time = mcp795_read_time,
+		.set_time = mcp795_set_time
+};
+
+static int mcp795_probe(struct spi_device *spi)
+{
+	struct rtc_device *rtc;
+	int ret;
+
+	spi->mode = SPI_MODE_0;
+	spi->bits_per_word = 8;
+	ret = spi_setup(spi);
+	if (ret) {
+		dev_err(&spi->dev, "Unable to setup SPI\n");
+		return ret;
+	}
+
+	/* Start the oscillator */
+	mcp795_rtcc_set_bits(&spi->dev, 0x01, MCP795_ST_BIT, MCP795_ST_BIT);
+	/* Clear the 12 hour mode flag*/
+	mcp795_rtcc_set_bits(&spi->dev, 0x03, MCP795_24_BIT, 0);
+
+	rtc = devm_rtc_device_register(&spi->dev, "rtc-mcp795",
+								&mcp795_rtc_ops, THIS_MODULE);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	spi_set_drvdata(spi, rtc);
+
+	return 0;
+}
+
+static struct spi_driver mcp795_driver = {
+		.driver = {
+				.name = "rtc-mcp795",
+				.owner = THIS_MODULE,
+		},
+		.probe = mcp795_probe,
+};
+
+module_spi_driver(mcp795_driver);
+
+MODULE_DESCRIPTION("MCP795 RTC SPI Driver");
+MODULE_AUTHOR("Josef Gajdusek <atx@atx.name>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("spi:mcp795");