Merge tag 'regmap-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap

Pull regmap updates from Mark Brown:
 "Quite a busy release for regmap, mostly support for new features
  useful on fairly small subsets of devices. The user visible features
  are:

   - A new API for registering large numbers of regmap fields at once.

   - Support for Intel AVMM buses connected via SPI.

   - Support for 12/20 address/value layouts.

   - Support for yet another scheme for acknowledging interrupts used on
     some Qualcomm devices"

* tag 'regmap-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
  regmap: irq: Add support to clear ack registers
  regmap: add support to regmap_field_bulk_alloc/free apis
  regmap: destroy mutex (if used) in regmap_exit()
  regmap: debugfs: use semicolons rather than commas to separate statements
  regmap: debugfs: Fix more error path regressions
  regmap: Add support for 12/20 register formatting
  regmap: Add can_sleep configuration option
  regmap: soundwire: remove unused header mod_devicetable.h
  regmap: Use flexible sleep
  regmap: add Intel SPI Slave to AVMM Bus Bridge support

8 files changed, 902 insertions, 8 deletions

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index 1d1d26b0d279..bcb90d8c3960 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -4,7 +4,7 @@
 # subsystems should select the appropriate symbols.
 
 config REGMAP
-	default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ || REGMAP_SOUNDWIRE || REGMAP_SCCB || REGMAP_I3C)
+	default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ || REGMAP_SOUNDWIRE || REGMAP_SCCB || REGMAP_I3C || REGMAP_SPI_AVMM)
 	select IRQ_DOMAIN if REGMAP_IRQ
 	bool
 
@@ -53,3 +53,7 @@ config REGMAP_SCCB
 config REGMAP_I3C
 	tristate
 	depends on I3C
+
+config REGMAP_SPI_AVMM
+	tristate
+	depends on SPI
diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index ff6c7d8ec1cd..ac1b69ee4051 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -17,3 +17,4 @@ obj-$(CONFIG_REGMAP_W1) += regmap-w1.o
 obj-$(CONFIG_REGMAP_SOUNDWIRE) += regmap-sdw.o
 obj-$(CONFIG_REGMAP_SCCB) += regmap-sccb.o
 obj-$(CONFIG_REGMAP_I3C) += regmap-i3c.o
+obj-$(CONFIG_REGMAP_SPI_AVMM) += regmap-spi-avmm.o
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 7be2fcfeea52..0097696c31de 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -161,6 +161,9 @@ struct regmap {
 	void *selector_work_buf;	/* Scratch buffer used for selector */
 
 	struct hwspinlock *hwlock;
+
+	/* if set, the regmap core can sleep */
+	bool can_sleep;
 };
 
 struct regcache_ops {
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c
index b6d63ef16b44..8dfac7f3ed7a 100644
--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -183,7 +183,7 @@ static inline void regmap_calc_tot_len(struct regmap *map,
 {
 	/* Calculate the length of a fixed format  */
 	if (!map->debugfs_tot_len) {
-		map->debugfs_reg_len = regmap_calc_reg_len(map->max_register),
+		map->debugfs_reg_len = regmap_calc_reg_len(map->max_register);
 		map->debugfs_val_len = 2 * map->format.val_bytes;
 		map->debugfs_tot_len = map->debugfs_reg_len +
 			map->debugfs_val_len + 3;      /* : \n */
diff --git a/drivers/base/regmap/regmap-irq.c b/drivers/base/regmap/regmap-irq.c
index 369a57e6f89d..ad5c2de395d1 100644
--- a/drivers/base/regmap/regmap-irq.c
+++ b/drivers/base/regmap/regmap-irq.c
@@ -168,6 +168,14 @@ static void regmap_irq_sync_unlock(struct irq_data *data)
 				ret = regmap_write(map, reg, ~d->mask_buf[i]);
 			else
 				ret = regmap_write(map, reg, d->mask_buf[i]);
+			if (d->chip->clear_ack) {
+				if (d->chip->ack_invert && !ret)
+					ret = regmap_write(map, reg,
+							   d->mask_buf[i]);
+				else if (!ret)
+					ret = regmap_write(map, reg,
+							   ~d->mask_buf[i]);
+			}
 			if (ret != 0)
 				dev_err(d->map->dev, "Failed to ack 0x%x: %d\n",
 					reg, ret);
@@ -493,7 +501,20 @@ static irqreturn_t regmap_irq_thread(int irq, void *d)
 		if (data->status_buf[i] && (chip->ack_base || chip->use_ack)) {
 			reg = chip->ack_base +
 				(i * map->reg_stride * data->irq_reg_stride);
-			ret = regmap_write(map, reg, data->status_buf[i]);
+			if (chip->ack_invert)
+				ret = regmap_write(map, reg,
+						~data->status_buf[i]);
+			else
+				ret = regmap_write(map, reg,
+						data->status_buf[i]);
+			if (chip->clear_ack) {
+				if (chip->ack_invert && !ret)
+					ret = regmap_write(map, reg,
+							data->status_buf[i]);
+				else if (!ret)
+					ret = regmap_write(map, reg,
+							~data->status_buf[i]);
+			}
 			if (ret != 0)
 				dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 					reg, ret);
@@ -722,6 +743,16 @@ int regmap_add_irq_chip_fwnode(struct fwnode_handle *fwnode,
 			else
 				ret = regmap_write(map, reg,
 					d->status_buf[i] & d->mask_buf[i]);
+			if (chip->clear_ack) {
+				if (chip->ack_invert && !ret)
+					ret = regmap_write(map, reg,
+						(d->status_buf[i] &
+						 d->mask_buf[i]));
+				else if (!ret)
+					ret = regmap_write(map, reg,
+						~(d->status_buf[i] &
+						  d->mask_buf[i]));
+			}
 			if (ret != 0) {
 				dev_err(map->dev, "Failed to ack 0x%x: %d\n",
 					reg, ret);
diff --git a/drivers/base/regmap/regmap-sdw.c b/drivers/base/regmap/regmap-sdw.c
index 50a66382d87d..c92d614b4943 100644
--- a/drivers/base/regmap/regmap-sdw.c
+++ b/drivers/base/regmap/regmap-sdw.c
@@ -2,7 +2,6 @@
 // Copyright(c) 2015-17 Intel Corporation.
 
 #include <linux/device.h>
-#include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/soundwire/sdw.h>
 #include "internal.h"
diff --git a/drivers/base/regmap/regmap-spi-avmm.c b/drivers/base/regmap/regmap-spi-avmm.c
new file mode 100644
index 000000000000..ad1da83e849f
--- /dev/null
+++ b/drivers/base/regmap/regmap-spi-avmm.c
@@ -0,0 +1,719 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Register map access API - SPI AVMM support
+//
+// Copyright (C) 2018-2020 Intel Corporation. All rights reserved.
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+
+/*
+ * This driver implements the regmap operations for a generic SPI
+ * master to access the registers of the spi slave chip which has an
+ * Avalone bus in it.
+ *
+ * The "SPI slave to Avalon Master Bridge" (spi-avmm) IP should be integrated
+ * in the spi slave chip. The IP acts as a bridge to convert encoded streams of
+ * bytes from the host to the internal register read/write on Avalon bus. In
+ * order to issue register access requests to the slave chip, the host should
+ * send formatted bytes that conform to the transfer protocol.
+ * The transfer protocol contains 3 layers: transaction layer, packet layer
+ * and physical layer.
+ *
+ * Reference Documents could be found at:
+ * https://www.intel.com/content/www/us/en/programmable/documentation/sfo1400787952932.html
+ *
+ * Chapter "SPI Slave/JTAG to Avalon Master Bridge Cores" is a general
+ * introduction to the protocol.
+ *
+ * Chapter "Avalon Packets to Transactions Converter Core" describes
+ * the transaction layer.
+ *
+ * Chapter "Avalon-ST Bytes to Packets and Packets to Bytes Converter Cores"
+ * describes the packet layer.
+ *
+ * Chapter "Avalon-ST Serial Peripheral Interface Core" describes the
+ * physical layer.
+ *
+ *
+ * When host issues a regmap read/write, the driver will transform the request
+ * to byte stream layer by layer. It formats the register addr, value and
+ * length to the transaction layer request, then converts the request to packet
+ * layer bytes stream and then to physical layer bytes stream. Finally the
+ * driver sends the formatted byte stream over SPI bus to the slave chip.
+ *
+ * The spi-avmm IP on the slave chip decodes the byte stream and initiates
+ * register read/write on its internal Avalon bus, and then encodes the
+ * response to byte stream and sends back to host.
+ *
+ * The driver receives the byte stream, reverses the 3 layers transformation,
+ * and finally gets the response value (read out data for register read,
+ * successful written size for register write).
+ */
+
+#define PKT_SOP			0x7a
+#define PKT_EOP			0x7b
+#define PKT_CHANNEL		0x7c
+#define PKT_ESC			0x7d
+
+#define PHY_IDLE		0x4a
+#define PHY_ESC			0x4d
+
+#define TRANS_CODE_WRITE	0x0
+#define TRANS_CODE_SEQ_WRITE	0x4
+#define TRANS_CODE_READ		0x10
+#define TRANS_CODE_SEQ_READ	0x14
+#define TRANS_CODE_NO_TRANS	0x7f
+
+#define SPI_AVMM_XFER_TIMEOUT	(msecs_to_jiffies(200))
+
+/* slave's register addr is 32 bits */
+#define SPI_AVMM_REG_SIZE		4UL
+/* slave's register value is 32 bits */
+#define SPI_AVMM_VAL_SIZE		4UL
+
+/*
+ * max rx size could be larger. But considering the buffer consuming,
+ * it is proper that we limit 1KB xfer at max.
+ */
+#define MAX_READ_CNT		256UL
+#define MAX_WRITE_CNT		1UL
+
+struct trans_req_header {
+	u8 code;
+	u8 rsvd;
+	__be16 size;
+	__be32 addr;
+} __packed;
+
+struct trans_resp_header {
+	u8 r_code;
+	u8 rsvd;
+	__be16 size;
+} __packed;
+
+#define TRANS_REQ_HD_SIZE	(sizeof(struct trans_req_header))
+#define TRANS_RESP_HD_SIZE	(sizeof(struct trans_resp_header))
+
+/*
+ * In transaction layer,
+ * the write request format is: Transaction request header + data
+ * the read request format is: Transaction request header
+ * the write response format is: Transaction response header
+ * the read response format is: pure data, no Transaction response header
+ */
+#define TRANS_WR_TX_SIZE(n)	(TRANS_REQ_HD_SIZE + SPI_AVMM_VAL_SIZE * (n))
+#define TRANS_RD_TX_SIZE	TRANS_REQ_HD_SIZE
+#define TRANS_TX_MAX		TRANS_WR_TX_SIZE(MAX_WRITE_CNT)
+
+#define TRANS_RD_RX_SIZE(n)	(SPI_AVMM_VAL_SIZE * (n))
+#define TRANS_WR_RX_SIZE	TRANS_RESP_HD_SIZE
+#define TRANS_RX_MAX		TRANS_RD_RX_SIZE(MAX_READ_CNT)
+
+/* tx & rx share one transaction layer buffer */
+#define TRANS_BUF_SIZE		((TRANS_TX_MAX > TRANS_RX_MAX) ?	\
+				 TRANS_TX_MAX : TRANS_RX_MAX)
+
+/*
+ * In tx phase, the host prepares all the phy layer bytes of a request in the
+ * phy buffer and sends them in a batch.
+ *
+ * The packet layer and physical layer defines several special chars for
+ * various purpose, when a transaction layer byte hits one of these special
+ * chars, it should be escaped. The escape rule is, "Escape char first,
+ * following the byte XOR'ed with 0x20".
+ *
+ * This macro defines the max possible length of the phy data. In the worst
+ * case, all transaction layer bytes need to be escaped (so the data length
+ * doubles), plus 4 special chars (SOP, CHANNEL, CHANNEL_NUM, EOP). Finally
+ * we should make sure the length is aligned to SPI BPW.
+ */
+#define PHY_TX_MAX		ALIGN(2 * TRANS_TX_MAX + 4, 4)
+
+/*
+ * Unlike tx, phy rx is affected by possible PHY_IDLE bytes from slave, the max
+ * length of the rx bit stream is unpredictable. So the driver reads the words
+ * one by one, and parses each word immediately into transaction layer buffer.
+ * Only one word length of phy buffer is used for rx.
+ */
+#define PHY_BUF_SIZE		PHY_TX_MAX
+
+/**
+ * struct spi_avmm_bridge - SPI slave to AVMM bus master bridge
+ *
+ * @spi: spi slave associated with this bridge.
+ * @word_len: bytes of word for spi transfer.
+ * @trans_len: length of valid data in trans_buf.
+ * @phy_len: length of valid data in phy_buf.
+ * @trans_buf: the bridge buffer for transaction layer data.
+ * @phy_buf: the bridge buffer for physical layer data.
+ * @swap_words: the word swapping cb for phy data. NULL if not needed.
+ *
+ * As a device's registers are implemented on the AVMM bus address space, it
+ * requires the driver to issue formatted requests to spi slave to AVMM bus
+ * master bridge to perform register access.
+ */
+struct spi_avmm_bridge {
+	struct spi_device *spi;
+	unsigned char word_len;
+	unsigned int trans_len;
+	unsigned int phy_len;
+	/* bridge buffer used in translation between protocol layers */
+	char trans_buf[TRANS_BUF_SIZE];
+	char phy_buf[PHY_BUF_SIZE];
+	void (*swap_words)(char *buf, unsigned int len);
+};
+
+static void br_swap_words_32(char *buf, unsigned int len)
+{
+	u32 *p = (u32 *)buf;
+	unsigned int count;
+
+	count = len / 4;
+	while (count--) {
+		*p = swab32p(p);
+		p++;
+	}
+}
+
+/*
+ * Format transaction layer data in br->trans_buf according to the register
+ * access request, Store valid transaction layer data length in br->trans_len.
+ */
+static int br_trans_tx_prepare(struct spi_avmm_bridge *br, bool is_read, u32 reg,
+			       u32 *wr_val, u32 count)
+{
+	struct trans_req_header *header;
+	unsigned int trans_len;
+	u8 code;
+	__le32 *data;
+	int i;
+
+	if (is_read) {
+		if (count == 1)
+			code = TRANS_CODE_READ;
+		else
+			code = TRANS_CODE_SEQ_READ;
+	} else {
+		if (count == 1)
+			code = TRANS_CODE_WRITE;
+		else
+			code = TRANS_CODE_SEQ_WRITE;
+	}
+
+	header = (struct trans_req_header *)br->trans_buf;
+	header->code = code;
+	header->rsvd = 0;
+	header->size = cpu_to_be16((u16)count * SPI_AVMM_VAL_SIZE);
+	header->addr = cpu_to_be32(reg);
+
+	trans_len = TRANS_REQ_HD_SIZE;
+
+	if (!is_read) {
+		trans_len += SPI_AVMM_VAL_SIZE * count;
+		if (trans_len > sizeof(br->trans_buf))
+			return -ENOMEM;
+
+		data = (__le32 *)(br->trans_buf + TRANS_REQ_HD_SIZE);
+
+		for (i = 0; i < count; i++)
+			*data++ = cpu_to_le32(*wr_val++);
+	}
+
+	/* Store valid trans data length for next layer */
+	br->trans_len = trans_len;
+
+	return 0;
+}
+
+/*
+ * Convert transaction layer data (in br->trans_buf) to phy layer data, store
+ * them in br->phy_buf. Pad the phy_buf aligned with SPI's BPW. Store valid phy
+ * layer data length in br->phy_len.
+ *
+ * phy_buf len should be aligned with SPI's BPW. Spare bytes should be padded
+ * with PHY_IDLE, then the slave will just drop them.
+ *
+ * The driver will not simply pad 4a at the tail. The concern is that driver
+ * will not store MISO data during tx phase, if the driver pads 4a at the tail,
+ * it is possible that if the slave is fast enough to response at the padding
+ * time. As a result these rx bytes are lost. In the following case, 7a,7c,00
+ * will lost.
+ * MOSI ...|7a|7c|00|10| |00|00|04|02| |4b|7d|5a|7b| |40|4a|4a|4a| |XX|XX|...
+ * MISO ...|4a|4a|4a|4a| |4a|4a|4a|4a| |4a|4a|4a|4a| |4a|7a|7c|00| |78|56|...
+ *
+ * So the driver moves EOP and bytes after EOP to the end of the aligned size,
+ * then fill the hole with PHY_IDLE. As following:
+ * before pad ...|7a|7c|00|10| |00|00|04|02| |4b|7d|5a|7b| |40|
+ * after pad  ...|7a|7c|00|10| |00|00|04|02| |4b|7d|5a|4a| |4a|4a|7b|40|
+ * Then if the slave will not get the entire packet before the tx phase is
+ * over, it can't responsed to anything either.
+ */
+static int br_pkt_phy_tx_prepare(struct spi_avmm_bridge *br)
+{
+	char *tb, *tb_end, *pb, *pb_limit, *pb_eop = NULL;
+	unsigned int aligned_phy_len, move_size;
+	bool need_esc = false;
+
+	tb = br->trans_buf;
+	tb_end = tb + br->trans_len;
+	pb = br->phy_buf;
+	pb_limit = pb + ARRAY_SIZE(br->phy_buf);
+
+	*pb++ = PKT_SOP;
+
+	/*
+	 * The driver doesn't support multiple channels so the channel number
+	 * is always 0.
+	 */
+	*pb++ = PKT_CHANNEL;
+	*pb++ = 0x0;
+
+	for (; pb < pb_limit && tb < tb_end; pb++) {
+		if (need_esc) {
+			*pb = *tb++ ^ 0x20;
+			need_esc = false;
+			continue;
+		}
+
+		/* EOP should be inserted before the last valid char */
+		if (tb == tb_end - 1 && !pb_eop) {
+			*pb = PKT_EOP;
+			pb_eop = pb;
+			continue;
+		}
+
+		/*
+		 * insert an ESCAPE char if the data value equals any special
+		 * char.
+		 */
+		switch (*tb) {
+		case PKT_SOP:
+		case PKT_EOP:
+		case PKT_CHANNEL:
+		case PKT_ESC:
+			*pb = PKT_ESC;
+			need_esc = true;
+			break;
+		case PHY_IDLE:
+		case PHY_ESC:
+			*pb = PHY_ESC;
+			need_esc = true;
+			break;
+		default:
+			*pb = *tb++;
+			break;
+		}
+	}
+
+	/* The phy buffer is used out but transaction layer data remains */
+	if (tb < tb_end)
+		return -ENOMEM;
+
+	/* Store valid phy data length for spi transfer */
+	br->phy_len = pb - br->phy_buf;
+
+	if (br->word_len == 1)
+		return 0;
+
+	/* Do phy buf padding if word_len > 1 byte. */
+	aligned_phy_len = ALIGN(br->phy_len, br->word_len);
+	if (aligned_phy_len > sizeof(br->phy_buf))
+		return -ENOMEM;
+
+	if (aligned_phy_len == br->phy_len)
+		return 0;
+
+	/* move EOP and bytes after EOP to the end of aligned size */
+	move_size = pb - pb_eop;
+	memmove(&br->phy_buf[aligned_phy_len - move_size], pb_eop, move_size);
+
+	/* fill the hole with PHY_IDLEs */
+	memset(pb_eop, PHY_IDLE, aligned_phy_len - br->phy_len);
+
+	/* update the phy data length */
+	br->phy_len = aligned_phy_len;
+
+	return 0;
+}
+
+/*
+ * In tx phase, the slave only returns PHY_IDLE (0x4a). So the driver will
+ * ignore rx in tx phase.
+ */
+static int br_do_tx(struct spi_avmm_bridge *br)
+{
+	/* reorder words for spi transfer */
+	if (br->swap_words)
+		br->swap_words(br->phy_buf, br->phy_len);
+
+	/* send all data in phy_buf  */
+	return spi_write(br->spi, br->phy_buf, br->phy_len);
+}
+
+/*
+ * This function read the rx byte stream from SPI word by word and convert
+ * them to transaction layer data in br->trans_buf. It also stores the length
+ * of rx transaction layer data in br->trans_len
+ *
+ * The slave may send an unknown number of PHY_IDLEs in rx phase, so we cannot
+ * prepare a fixed length buffer to receive all of the rx data in a batch. We
+ * have to read word by word and convert them to transaction layer data at
+ * once.
+ */
+static int br_do_rx_and_pkt_phy_parse(struct spi_avmm_bridge *br)
+{
+	bool eop_found = false, channel_found = false, esc_found = false;
+	bool valid_word = false, last_try = false;
+	struct device *dev = &br->spi->dev;
+	char *pb, *tb_limit, *tb = NULL;
+	unsigned long poll_timeout;
+	int ret, i;
+
+	tb_limit = br->trans_buf + ARRAY_SIZE(br->trans_buf);
+	pb = br->phy_buf;
+	poll_timeout = jiffies + SPI_AVMM_XFER_TIMEOUT;
+	while (tb < tb_limit) {
+		ret = spi_read(br->spi, pb, br->word_len);
+		if (ret)
+			return ret;
+
+		/* reorder the word back */
+		if (br->swap_words)
+			br->swap_words(pb, br->word_len);
+
+		valid_word = false;
+		for (i = 0; i < br->word_len; i++) {
+			/* drop everything before first SOP */
+			if (!tb && pb[i] != PKT_SOP)
+				continue;
+
+			/* drop PHY_IDLE */
+			if (pb[i] == PHY_IDLE)
+				continue;
+
+			valid_word = true;
+
+			/*
+			 * We don't support multiple channels, so error out if
+			 * a non-zero channel number is found.
+			 */
+			if (channel_found) {
+				if (pb[i] != 0) {
+					dev_err(dev, "%s channel num != 0\n",
+						__func__);
+					return -EFAULT;
+				}
+
+				channel_found = false;
+				continue;
+			}
+
+			switch (pb[i]) {
+			case PKT_SOP:
+				/*
+				 * reset the parsing if a second SOP appears.
+				 */
+				tb = br->trans_buf;
+				eop_found = false;
+				channel_found = false;
+				esc_found = false;
+				break;
+			case PKT_EOP:
+				/*
+				 * No special char is expected after ESC char.
+				 * No special char (except ESC & PHY_IDLE) is
+				 * expected after EOP char.
+				 *
+				 * The special chars are all dropped.
+				 */
+				if (esc_found || eop_found)
+					return -EFAULT;
+
+				eop_found = true;
+				break;
+			case PKT_CHANNEL:
+				if (esc_found || eop_found)
+					return -EFAULT;
+
+				channel_found = true;
+				break;
+			case PKT_ESC:
+			case PHY_ESC:
+				if (esc_found)
+					return -EFAULT;
+
+				esc_found = true;
+				break;
+			default:
+				/* Record the normal byte in trans_buf. */
+				if (esc_found) {
+					*tb++ = pb[i] ^ 0x20;
+					esc_found = false;
+				} else {
+					*tb++ = pb[i];
+				}
+
+				/*
+				 * We get the last normal byte after EOP, it is
+				 * time we finish. Normally the function should
+				 * return here.
+				 */
+				if (eop_found) {
+					br->trans_len = tb - br->trans_buf;
+					return 0;
+				}
+			}
+		}
+
+		if (valid_word) {
+			/* update poll timeout when we get valid word */
+			poll_timeout = jiffies + SPI_AVMM_XFER_TIMEOUT;
+			last_try = false;
+		} else {
+			/*
+			 * We timeout when rx keeps invalid for some time. But
+			 * it is possible we are scheduled out for long time
+			 * after a spi_read. So when we are scheduled in, a SW
+			 * timeout happens. But actually HW may have worked fine and
+			 * has been ready long time ago. So we need to do an extra
+			 * read, if we get a valid word then we could continue rx,
+			 * otherwise real a HW issue happens.
+			 */
+			if (last_try)
+				return -ETIMEDOUT;
+
+			if (time_after(jiffies, poll_timeout))
+				last_try = true;
+		}
+	}
+
+	/*
+	 * We have used out all transfer layer buffer but cannot find the end
+	 * of the byte stream.
+	 */
+	dev_err(dev, "%s transfer buffer is full but rx doesn't end\n",
+		__func__);
+
+	return -EFAULT;
+}
+
+/*
+ * For read transactions, the avmm bus will directly return register values
+ * without transaction response header.
+ */
+static int br_rd_trans_rx_parse(struct spi_avmm_bridge *br,
+				u32 *val, unsigned int expected_count)
+{
+	unsigned int i, trans_len = br->trans_len;
+	__le32 *data;
+
+	if (expected_count * SPI_AVMM_VAL_SIZE != trans_len)
+		return -EFAULT;
+
+	data = (__le32 *)br->trans_buf;
+	for (i = 0; i < expected_count; i++)
+		*val++ = le32_to_cpu(*data++);
+
+	return 0;
+}
+
+/*
+ * For write transactions, the slave will return a transaction response
+ * header.
+ */
+static int br_wr_trans_rx_parse(struct spi_avmm_bridge *br,
+				unsigned int expected_count)
+{
+	unsigned int trans_len = br->trans_len;
+	struct trans_resp_header *resp;
+	u8 code;
+	u16 val_len;
+
+	if (trans_len != TRANS_RESP_HD_SIZE)
+		return -EFAULT;
+
+	resp = (struct trans_resp_header *)br->trans_buf;
+
+	code = resp->r_code ^ 0x80;
+	val_len = be16_to_cpu(resp->size);
+	if (!val_len || val_len != expected_count * SPI_AVMM_VAL_SIZE)
+		return -EFAULT;
+
+	/* error out if the trans code doesn't align with the val size */
+	if ((val_len == SPI_AVMM_VAL_SIZE && code != TRANS_CODE_WRITE) ||
+	    (val_len > SPI_AVMM_VAL_SIZE && code != TRANS_CODE_SEQ_WRITE))
+		return -EFAULT;
+
+	return 0;
+}
+
+static int do_reg_access(void *context, bool is_read, unsigned int reg,
+			 unsigned int *value, unsigned int count)
+{
+	struct spi_avmm_bridge *br = context;
+	int ret;
+
+	/* invalidate bridge buffers first */
+	br->trans_len = 0;
+	br->phy_len = 0;
+
+	ret = br_trans_tx_prepare(br, is_read, reg, value, count);
+	if (ret)
+		return ret;
+
+	ret = br_pkt_phy_tx_prepare(br);
+	if (ret)
+		return ret;
+
+	ret = br_do_tx(br);
+	if (ret)
+		return ret;
+
+	ret = br_do_rx_and_pkt_phy_parse(br);
+	if (ret)
+		return ret;
+
+	if (is_read)
+		return br_rd_trans_rx_parse(br, value, count);
+	else
+		return br_wr_trans_rx_parse(br, count);
+}
+
+static int regmap_spi_avmm_gather_write(void *context,
+					const void *reg_buf, size_t reg_len,
+					const void *val_buf, size_t val_len)
+{
+	if (reg_len != SPI_AVMM_REG_SIZE)
+		return -EINVAL;
+
+	if (!IS_ALIGNED(val_len, SPI_AVMM_VAL_SIZE))
+		return -EINVAL;
+
+	return do_reg_access(context, false, *(u32 *)reg_buf, (u32 *)val_buf,
+			     val_len / SPI_AVMM_VAL_SIZE);
+}
+
+static int regmap_spi_avmm_write(void *context, const void *data, size_t bytes)
+{
+	if (bytes < SPI_AVMM_REG_SIZE + SPI_AVMM_VAL_SIZE)
+		return -EINVAL;
+
+	return regmap_spi_avmm_gather_write(context, data, SPI_AVMM_REG_SIZE,
+					    data + SPI_AVMM_REG_SIZE,
+					    bytes - SPI_AVMM_REG_SIZE);
+}
+
+static int regmap_spi_avmm_read(void *context,
+				const void *reg_buf, size_t reg_len,
+				void *val_buf, size_t val_len)
+{
+	if (reg_len != SPI_AVMM_REG_SIZE)
+		return -EINVAL;
+
+	if (!IS_ALIGNED(val_len, SPI_AVMM_VAL_SIZE))
+		return -EINVAL;
+
+	return do_reg_access(context, true, *(u32 *)reg_buf, val_buf,
+			     (val_len / SPI_AVMM_VAL_SIZE));
+}
+
+static struct spi_avmm_bridge *
+spi_avmm_bridge_ctx_gen(struct spi_device *spi)
+{
+	struct spi_avmm_bridge *br;
+
+	if (!spi)
+		return ERR_PTR(-ENODEV);
+
+	/* Only support BPW == 8 or 32 now. Try 32 BPW first. */
+	spi->mode = SPI_MODE_1;
+	spi->bits_per_word = 32;
+	if (spi_setup(spi)) {
+		spi->bits_per_word = 8;
+		if (spi_setup(spi))
+			return ERR_PTR(-EINVAL);
+	}
+
+	br = kzalloc(sizeof(*br), GFP_KERNEL);
+	if (!br)
+		return ERR_PTR(-ENOMEM);
+
+	br->spi = spi;
+	br->word_len = spi->bits_per_word / 8;
+	if (br->word_len == 4) {
+		/*
+		 * The protocol requires little endian byte order but MSB
+		 * first. So driver needs to swap the byte order word by word
+		 * if word length > 1.
+		 */
+		br->swap_words = br_swap_words_32;
+	}
+
+	return br;
+}
+
+static void spi_avmm_bridge_ctx_free(void *context)
+{
+	kfree(context);
+}
+
+static const struct regmap_bus regmap_spi_avmm_bus = {
+	.write = regmap_spi_avmm_write,
+	.gather_write = regmap_spi_avmm_gather_write,
+	.read = regmap_spi_avmm_read,
+	.reg_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.val_format_endian_default = REGMAP_ENDIAN_NATIVE,
+	.max_raw_read = SPI_AVMM_VAL_SIZE * MAX_READ_CNT,
+	.max_raw_write = SPI_AVMM_VAL_SIZE * MAX_WRITE_CNT,
+	.free_context = spi_avmm_bridge_ctx_free,
+};
+
+struct regmap *__regmap_init_spi_avmm(struct spi_device *spi,
+				      const struct regmap_config *config,
+				      struct lock_class_key *lock_key,
+				      const char *lock_name)
+{
+	struct spi_avmm_bridge *bridge;
+	struct regmap *map;
+
+	bridge = spi_avmm_bridge_ctx_gen(spi);
+	if (IS_ERR(bridge))
+		return ERR_CAST(bridge);
+
+	map = __regmap_init(&spi->dev, &regmap_spi_avmm_bus,
+			    bridge, config, lock_key, lock_name);
+	if (IS_ERR(map)) {
+		spi_avmm_bridge_ctx_free(bridge);
+		return ERR_CAST(map);
+	}
+
+	return map;
+}
+EXPORT_SYMBOL_GPL(__regmap_init_spi_avmm);
+
+struct regmap *__devm_regmap_init_spi_avmm(struct spi_device *spi,
+					   const struct regmap_config *config,
+					   struct lock_class_key *lock_key,
+					   const char *lock_name)
+{
+	struct spi_avmm_bridge *bridge;
+	struct regmap *map;
+
+	bridge = spi_avmm_bridge_ctx_gen(spi);
+	if (IS_ERR(bridge))
+		return ERR_CAST(bridge);
+
+	map = __devm_regmap_init(&spi->dev, &regmap_spi_avmm_bus,
+				 bridge, config, lock_key, lock_name);
+	if (IS_ERR(map)) {
+		spi_avmm_bridge_ctx_free(bridge);
+		return ERR_CAST(map);
+	}
+
+	return map;
+}
+EXPORT_SYMBOL_GPL(__devm_regmap_init_spi_avmm);
+
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index b71f9ecddff5..5db536ccfcd6 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -209,6 +209,18 @@ static bool regmap_volatile_range(struct regmap *map, unsigned int reg,
 	return true;
 }
 
+static void regmap_format_12_20_write(struct regmap *map,
+				     unsigned int reg, unsigned int val)
+{
+	u8 *out = map->work_buf;
+
+	out[0] = reg >> 4;
+	out[1] = (reg << 4) | (val >> 16);
+	out[2] = val >> 8;
+	out[3] = val;
+}
+
+
 static void regmap_format_2_6_write(struct regmap *map,
 				     unsigned int reg, unsigned int val)
 {
@@ -711,13 +723,17 @@ struct regmap *__regmap_init(struct device *dev,
 	if (ret)
 		goto err_map;
 
+	ret = -EINVAL; /* Later error paths rely on this */
+
 	if (config->disable_locking) {
 		map->lock = map->unlock = regmap_lock_unlock_none;
+		map->can_sleep = config->can_sleep;
 		regmap_debugfs_disable(map);
 	} else if (config->lock && config->unlock) {
 		map->lock = config->lock;
 		map->unlock = config->unlock;
 		map->lock_arg = config->lock_arg;
+		map->can_sleep = config->can_sleep;
 	} else if (config->use_hwlock) {
 		map->hwlock = hwspin_lock_request_specific(config->hwlock_id);
 		if (!map->hwlock) {
@@ -753,6 +769,7 @@ struct regmap *__regmap_init(struct device *dev,
 			mutex_init(&map->mutex);
 			map->lock = regmap_lock_mutex;
 			map->unlock = regmap_unlock_mutex;
+			map->can_sleep = true;
 			lockdep_set_class_and_name(&map->mutex,
 						   lock_key, lock_name);
 		}
@@ -883,6 +900,16 @@ struct regmap *__regmap_init(struct device *dev,
 		}
 		break;
 
+	case 12:
+		switch (config->val_bits) {
+		case 20:
+			map->format.format_write = regmap_format_12_20_write;
+			break;
+		default:
+			goto err_hwlock;
+		}
+		break;
+
 	case 8:
 		map->format.format_reg = regmap_format_8;
 		break;
@@ -1243,6 +1270,106 @@ struct regmap_field *devm_regmap_field_alloc(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_regmap_field_alloc);
 
+
+/**
+ * regmap_field_bulk_alloc() - Allocate and initialise a bulk register field.
+ *
+ * @regmap: regmap bank in which this register field is located.
+ * @rm_field: regmap register fields within the bank.
+ * @reg_field: Register fields within the bank.
+ * @num_fields: Number of register fields.
+ *
+ * The return value will be an -ENOMEM on error or zero for success.
+ * Newly allocated regmap_fields should be freed by calling
+ * regmap_field_bulk_free()
+ */
+int regmap_field_bulk_alloc(struct regmap *regmap,
+			    struct regmap_field **rm_field,
+			    struct reg_field *reg_field,
+			    int num_fields)
+{
+	struct regmap_field *rf;
+	int i;
+
+	rf = kcalloc(num_fields, sizeof(*rf), GFP_KERNEL);
+	if (!rf)
+		return -ENOMEM;
+
+	for (i = 0; i < num_fields; i++) {
+		regmap_field_init(&rf[i], regmap, reg_field[i]);
+		rm_field[i] = &rf[i];
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(regmap_field_bulk_alloc);
+
+/**
+ * devm_regmap_field_bulk_alloc() - Allocate and initialise a bulk register
+ * fields.
+ *
+ * @dev: Device that will be interacted with
+ * @regmap: regmap bank in which this register field is located.
+ * @rm_field: regmap register fields within the bank.
+ * @reg_field: Register fields within the bank.
+ * @num_fields: Number of register fields.
+ *
+ * The return value will be an -ENOMEM on error or zero for success.
+ * Newly allocated regmap_fields will be automatically freed by the
+ * device management code.
+ */
+int devm_regmap_field_bulk_alloc(struct device *dev,
+				 struct regmap *regmap,
+				 struct regmap_field **rm_field,
+				 struct reg_field *reg_field,
+				 int num_fields)
+{
+	struct regmap_field *rf;
+	int i;
+
+	rf = devm_kcalloc(dev, num_fields, sizeof(*rf), GFP_KERNEL);
+	if (!rf)
+		return -ENOMEM;
+
+	for (i = 0; i < num_fields; i++) {
+		regmap_field_init(&rf[i], regmap, reg_field[i]);
+		rm_field[i] = &rf[i];
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(devm_regmap_field_bulk_alloc);
+
+/**
+ * regmap_field_bulk_free() - Free register field allocated using
+ *                       regmap_field_bulk_alloc.
+ *
+ * @field: regmap fields which should be freed.
+ */
+void regmap_field_bulk_free(struct regmap_field *field)
+{
+	kfree(field);
+}
+EXPORT_SYMBOL_GPL(regmap_field_bulk_free);
+
+/**
+ * devm_regmap_field_bulk_free() - Free a bulk register field allocated using
+ *                            devm_regmap_field_bulk_alloc.
+ *
+ * @dev: Device that will be interacted with
+ * @field: regmap field which should be freed.
+ *
+ * Free register field allocated using devm_regmap_field_bulk_alloc(). Usually
+ * drivers need not call this function, as the memory allocated via devm
+ * will be freed as per device-driver life-cycle.
+ */
+void devm_regmap_field_bulk_free(struct device *dev,
+				 struct regmap_field *field)
+{
+	devm_kfree(dev, field);
+}
+EXPORT_SYMBOL_GPL(devm_regmap_field_bulk_free);
+
 /**
  * devm_regmap_field_free() - Free a register field allocated using
  *                            devm_regmap_field_alloc.
@@ -1365,6 +1492,8 @@ void regmap_exit(struct regmap *map)
 	}
 	if (map->hwlock)
 		hwspin_lock_free(map->hwlock);
+	if (map->lock == regmap_lock_mutex)
+		mutex_destroy(&map->mutex);
 	kfree_const(map->name);
 	kfree(map->patch);
 	kfree(map);
@@ -2253,8 +2382,12 @@ static int _regmap_range_multi_paged_reg_write(struct regmap *map,
 				if (ret != 0)
 					return ret;
 
-				if (regs[i].delay_us)
-					udelay(regs[i].delay_us);
+				if (regs[i].delay_us) {
+					if (map->can_sleep)
+						fsleep(regs[i].delay_us);
+					else
+						udelay(regs[i].delay_us);
+				}
 
 				base += n;
 				n = 0;
@@ -2290,8 +2423,12 @@ static int _regmap_multi_reg_write(struct regmap *map,
 			if (ret != 0)
 				return ret;
 
-			if (regs[i].delay_us)
-				udelay(regs[i].delay_us);
+			if (regs[i].delay_us) {
+				if (map->can_sleep)
+					fsleep(regs[i].delay_us);
+				else
+					udelay(regs[i].delay_us);
+			}
 		}
 		return 0;
 	}