Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc driver updates from Greg KH:
 "Here is the bit set of char/misc drivers for 4.19-rc1

  There is a lot here, much more than normal, seems like everyone is
  writing new driver subsystems these days... Anyway, major things here
  are:

   - new FSI driver subsystem, yet-another-powerpc low-level hardware
     bus

   - gnss, finally an in-kernel GPS subsystem to try to tame all of the
     crazy out-of-tree drivers that have been floating around for years,
     combined with some really hacky userspace implementations. This is
     only for GNSS receivers, but you have to start somewhere, and this
     is great to see.

  Other than that, there are new slimbus drivers, new coresight drivers,
  new fpga drivers, and loads of DT bindings for all of these and
  existing drivers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
  android: binder: Rate-limit debug and userspace triggered err msgs
  fsi: sbefifo: Bump max command length
  fsi: scom: Fix NULL dereference
  misc: mic: SCIF Fix scif_get_new_port() error handling
  misc: cxl: changed asterisk position
  genwqe: card_base: Use true and false for boolean values
  misc: eeprom: assignment outside the if statement
  uio: potential double frees if __uio_register_device() fails
  eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency
  misc: ti-st: Fix memory leak in the error path of probe()
  android: binder: Show extra_buffers_size in trace
  firmware: vpd: Fix section enabled flag on vpd_section_destroy
  platform: goldfish: Retire pdev_bus
  goldfish: Use dedicated macros instead of manual bit shifting
  goldfish: Add missing includes to goldfish.h
  mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux
  dt-bindings: mux: add adi,adgs1408
  Drivers: hv: vmbus: Cleanup synic memory free path
  Drivers: hv: vmbus: Remove use of slow_virt_to_phys()
  Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()
  ...

1 files changed, 338 insertions, 133 deletions

diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c
index 3f487449a277..4eb3a766fd4a 100644
--- a/drivers/fsi/fsi-master-gpio.c
+++ b/drivers/fsi/fsi-master-gpio.c
@@ -8,59 +8,31 @@
 #include <linux/fsi.h>
 #include <linux/gpio/consumer.h>
 #include <linux/io.h>
+#include <linux/irqflags.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
-#include <linux/spinlock.h>
 
 #include "fsi-master.h"
 
 #define	FSI_GPIO_STD_DLY	1	/* Standard pin delay in nS */
-#define	FSI_ECHO_DELAY_CLOCKS	16	/* Number clocks for echo delay */
-#define	FSI_PRE_BREAK_CLOCKS	50	/* Number clocks to prep for break */
-#define	FSI_BREAK_CLOCKS	256	/* Number of clocks to issue break */
-#define	FSI_POST_BREAK_CLOCKS	16000	/* Number clocks to set up cfam */
-#define	FSI_INIT_CLOCKS		5000	/* Clock out any old data */
-#define	FSI_GPIO_STD_DELAY	10	/* Standard GPIO delay in nS */
-					/* todo: adjust down as low as */
-					/* possible or eliminate */
-#define	FSI_GPIO_CMD_DPOLL      0x2
-#define	FSI_GPIO_CMD_TERM	0x3f
-#define FSI_GPIO_CMD_ABS_AR	0x4
-
-#define	FSI_GPIO_DPOLL_CLOCKS	100      /* < 21 will cause slave to hang */
-
-/* Bus errors */
-#define	FSI_GPIO_ERR_BUSY	1	/* Slave stuck in busy state */
-#define	FSI_GPIO_RESP_ERRA	2	/* Any (misc) Error */
-#define	FSI_GPIO_RESP_ERRC	3	/* Slave reports master CRC error */
-#define	FSI_GPIO_MTOE		4	/* Master time out error */
-#define	FSI_GPIO_CRC_INVAL	5	/* Master reports slave CRC error */
-
-/* Normal slave responses */
-#define	FSI_GPIO_RESP_BUSY	1
-#define	FSI_GPIO_RESP_ACK	0
-#define	FSI_GPIO_RESP_ACKD	4
-
-#define	FSI_GPIO_MAX_BUSY	100
-#define	FSI_GPIO_MTOE_COUNT	1000
-#define	FSI_GPIO_DRAIN_BITS	20
-#define	FSI_GPIO_CRC_SIZE	4
-#define	FSI_GPIO_MSG_ID_SIZE		2
-#define	FSI_GPIO_MSG_RESPID_SIZE	2
-#define	FSI_GPIO_PRIME_SLAVE_CLOCKS	100
+#define LAST_ADDR_INVALID		0x1
 
 struct fsi_master_gpio {
 	struct fsi_master	master;
 	struct device		*dev;
-	spinlock_t		cmd_lock;	/* Lock for commands */
+	struct mutex		cmd_lock;	/* mutex for command ordering */
 	struct gpio_desc	*gpio_clk;
 	struct gpio_desc	*gpio_data;
 	struct gpio_desc	*gpio_trans;	/* Voltage translator */
 	struct gpio_desc	*gpio_enable;	/* FSI enable */
 	struct gpio_desc	*gpio_mux;	/* Mux control */
 	bool			external_mode;
+	bool			no_delays;
+	uint32_t		last_addr;
+	uint8_t			t_send_delay;
+	uint8_t			t_echo_delay;
 };
 
 #define CREATE_TRACE_POINTS
@@ -78,19 +50,31 @@ static void clock_toggle(struct fsi_master_gpio *master, int count)
 	int i;
 
 	for (i = 0; i < count; i++) {
-		ndelay(FSI_GPIO_STD_DLY);
+		if (!master->no_delays)
+			ndelay(FSI_GPIO_STD_DLY);
 		gpiod_set_value(master->gpio_clk, 0);
-		ndelay(FSI_GPIO_STD_DLY);
+		if (!master->no_delays)
+			ndelay(FSI_GPIO_STD_DLY);
 		gpiod_set_value(master->gpio_clk, 1);
 	}
 }
 
-static int sda_in(struct fsi_master_gpio *master)
+static int sda_clock_in(struct fsi_master_gpio *master)
 {
 	int in;
 
-	ndelay(FSI_GPIO_STD_DLY);
+	if (!master->no_delays)
+		ndelay(FSI_GPIO_STD_DLY);
+	gpiod_set_value(master->gpio_clk, 0);
+
+	/* Dummy read to feed the synchronizers */
+	gpiod_get_value(master->gpio_data);
+
+	/* Actual data read */
 	in = gpiod_get_value(master->gpio_data);
+	if (!master->no_delays)
+		ndelay(FSI_GPIO_STD_DLY);
+	gpiod_set_value(master->gpio_clk, 1);
 	return in ? 1 : 0;
 }
 
@@ -113,10 +97,17 @@ static void set_sda_output(struct fsi_master_gpio *master, int value)
 
 static void clock_zeros(struct fsi_master_gpio *master, int count)
 {
+	trace_fsi_master_gpio_clock_zeros(master, count);
 	set_sda_output(master, 1);
 	clock_toggle(master, count);
 }
 
+static void echo_delay(struct fsi_master_gpio *master)
+{
+	clock_zeros(master, master->t_echo_delay);
+}
+
+
 static void serial_in(struct fsi_master_gpio *master, struct fsi_gpio_msg *msg,
 			uint8_t num_bits)
 {
@@ -125,8 +116,7 @@ static void serial_in(struct fsi_master_gpio *master, struct fsi_gpio_msg *msg,
 	set_sda_input(master);
 
 	for (bit = 0; bit < num_bits; bit++) {
-		clock_toggle(master, 1);
-		in_bit = sda_in(master);
+		in_bit = sda_clock_in(master);
 		msg->msg <<= 1;
 		msg->msg |= ~in_bit & 0x1;	/* Data is active low */
 	}
@@ -191,22 +181,92 @@ static void msg_push_crc(struct fsi_gpio_msg *msg)
 	msg_push_bits(msg, crc, 4);
 }
 
+static bool check_same_address(struct fsi_master_gpio *master, int id,
+		uint32_t addr)
+{
+	/* this will also handle LAST_ADDR_INVALID */
+	return master->last_addr == (((id & 0x3) << 21) | (addr & ~0x3));
+}
+
+static bool check_relative_address(struct fsi_master_gpio *master, int id,
+		uint32_t addr, uint32_t *rel_addrp)
+{
+	uint32_t last_addr = master->last_addr;
+	int32_t rel_addr;
+
+	if (last_addr == LAST_ADDR_INVALID)
+		return false;
+
+	/* We may be in 23-bit addressing mode, which uses the id as the
+	 * top two address bits. So, if we're referencing a different ID,
+	 * use absolute addresses.
+	 */
+	if (((last_addr >> 21) & 0x3) != id)
+		return false;
+
+	/* remove the top two bits from any 23-bit addressing */
+	last_addr &= (1 << 21) - 1;
+
+	/* We know that the addresses are limited to 21 bits, so this won't
+	 * overflow the signed rel_addr */
+	rel_addr = addr - last_addr;
+	if (rel_addr > 255 || rel_addr < -256)
+		return false;
+
+	*rel_addrp = (uint32_t)rel_addr;
+
+	return true;
+}
+
+static void last_address_update(struct fsi_master_gpio *master,
+		int id, bool valid, uint32_t addr)
+{
+	if (!valid)
+		master->last_addr = LAST_ADDR_INVALID;
+	else
+		master->last_addr = ((id & 0x3) << 21) | (addr & ~0x3);
+}
+
 /*
- * Encode an Absolute Address command
+ * Encode an Absolute/Relative/Same Address command
  */
-static void build_abs_ar_command(struct fsi_gpio_msg *cmd,
-		uint8_t id, uint32_t addr, size_t size, const void *data)
+static void build_ar_command(struct fsi_master_gpio *master,
+		struct fsi_gpio_msg *cmd, uint8_t id,
+		uint32_t addr, size_t size, const void *data)
 {
+	int i, addr_bits, opcode_bits;
 	bool write = !!data;
-	uint8_t ds;
-	int i;
+	uint8_t ds, opcode;
+	uint32_t rel_addr;
 
 	cmd->bits = 0;
 	cmd->msg = 0;
 
-	msg_push_bits(cmd, id, 2);
-	msg_push_bits(cmd, FSI_GPIO_CMD_ABS_AR, 3);
-	msg_push_bits(cmd, write ? 0 : 1, 1);
+	/* we have 21 bits of address max */
+	addr &= ((1 << 21) - 1);
+
+	/* cmd opcodes are variable length - SAME_AR is only two bits */
+	opcode_bits = 3;
+
+	if (check_same_address(master, id, addr)) {
+		/* we still address the byte offset within the word */
+		addr_bits = 2;
+		opcode_bits = 2;
+		opcode = FSI_CMD_SAME_AR;
+		trace_fsi_master_gpio_cmd_same_addr(master);
+
+	} else if (check_relative_address(master, id, addr, &rel_addr)) {
+		/* 8 bits plus sign */
+		addr_bits = 9;
+		addr = rel_addr;
+		opcode = FSI_CMD_REL_AR;
+		trace_fsi_master_gpio_cmd_rel_addr(master, rel_addr);
+
+	} else {
+		addr_bits = 21;
+		opcode = FSI_CMD_ABS_AR;
+		trace_fsi_master_gpio_cmd_abs_addr(master, addr);
+	}
 
 	/*
 	 * The read/write size is encoded in the lower bits of the address
@@ -223,7 +283,10 @@ static void build_abs_ar_command(struct fsi_gpio_msg *cmd,
 	if (size == 4)
 		addr |= 1;
 
-	msg_push_bits(cmd, addr & ((1 << 21) - 1), 21);
+	msg_push_bits(cmd, id, 2);
+	msg_push_bits(cmd, opcode, opcode_bits);
+	msg_push_bits(cmd, write ? 0 : 1, 1);
+	msg_push_bits(cmd, addr, addr_bits);
 	msg_push_bits(cmd, ds, 1);
 	for (i = 0; write && i < size; i++)
 		msg_push_bits(cmd, ((uint8_t *)data)[i], 8);
@@ -237,14 +300,18 @@ static void build_dpoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id)
 	cmd->msg = 0;
 
 	msg_push_bits(cmd, slave_id, 2);
-	msg_push_bits(cmd, FSI_GPIO_CMD_DPOLL, 3);
+	msg_push_bits(cmd, FSI_CMD_DPOLL, 3);
 	msg_push_crc(cmd);
 }
 
-static void echo_delay(struct fsi_master_gpio *master)
+static void build_epoll_command(struct fsi_gpio_msg *cmd, uint8_t slave_id)
 {
-	set_sda_output(master, 1);
-	clock_toggle(master, FSI_ECHO_DELAY_CLOCKS);
+	cmd->bits = 0;
+	cmd->msg = 0;
+
+	msg_push_bits(cmd, slave_id, 2);
+	msg_push_bits(cmd, FSI_CMD_EPOLL, 3);
+	msg_push_crc(cmd);
 }
 
 static void build_term_command(struct fsi_gpio_msg *cmd, uint8_t slave_id)
@@ -253,40 +320,40 @@ static void build_term_command(struct fsi_gpio_msg *cmd, uint8_t slave_id)
 	cmd->msg = 0;
 
 	msg_push_bits(cmd, slave_id, 2);
-	msg_push_bits(cmd, FSI_GPIO_CMD_TERM, 6);
+	msg_push_bits(cmd, FSI_CMD_TERM, 6);
 	msg_push_crc(cmd);
 }
 
 /*
- * Store information on master errors so handler can detect and clean
- * up the bus
+ * Note: callers rely specifically on this returning -EAGAIN for
+ * a CRC error detected in the response. Use other error code
+ * for other situations. It will be converted to something else
+ * higher up the stack before it reaches userspace.
  */
-static void fsi_master_gpio_error(struct fsi_master_gpio *master, int error)
-{
-
-}
-
 static int read_one_response(struct fsi_master_gpio *master,
 		uint8_t data_size, struct fsi_gpio_msg *msgp, uint8_t *tagp)
 {
 	struct fsi_gpio_msg msg;
-	uint8_t id, tag;
+	unsigned long flags;
 	uint32_t crc;
+	uint8_t tag;
 	int i;
 
+	local_irq_save(flags);
+
 	/* wait for the start bit */
-	for (i = 0; i < FSI_GPIO_MTOE_COUNT; i++) {
+	for (i = 0; i < FSI_MASTER_MTOE_COUNT; i++) {
 		msg.bits = 0;
 		msg.msg = 0;
 		serial_in(master, &msg, 1);
 		if (msg.msg)
 			break;
 	}
-	if (i == FSI_GPIO_MTOE_COUNT) {
+	if (i == FSI_MASTER_MTOE_COUNT) {
 		dev_dbg(master->dev,
 			"Master time out waiting for response\n");
-		fsi_master_gpio_error(master, FSI_GPIO_MTOE);
-		return -EIO;
+		local_irq_restore(flags);
+		return -ETIMEDOUT;
 	}
 
 	msg.bits = 0;
@@ -295,23 +362,27 @@ static int read_one_response(struct fsi_master_gpio *master,
 	/* Read slave ID & response tag */
 	serial_in(master, &msg, 4);
 
-	id = (msg.msg >> FSI_GPIO_MSG_RESPID_SIZE) & 0x3;
 	tag = msg.msg & 0x3;
 
 	/* If we have an ACK and we're expecting data, clock the data in too */
-	if (tag == FSI_GPIO_RESP_ACK && data_size)
+	if (tag == FSI_RESP_ACK && data_size)
 		serial_in(master, &msg, data_size * 8);
 
 	/* read CRC */
-	serial_in(master, &msg, FSI_GPIO_CRC_SIZE);
+	serial_in(master, &msg, FSI_CRC_SIZE);
+
+	local_irq_restore(flags);
 
 	/* we have a whole message now; check CRC */
 	crc = crc4(0, 1, 1);
 	crc = crc4(crc, msg.msg, msg.bits);
 	if (crc) {
-		dev_dbg(master->dev, "ERR response CRC\n");
-		fsi_master_gpio_error(master, FSI_GPIO_CRC_INVAL);
-		return -EIO;
+		/* Check if it's all 1's, that probably means the host is off */
+		if (((~msg.msg) & ((1ull << msg.bits) - 1)) == 0)
+			return -ENODEV;
+		dev_dbg(master->dev, "ERR response CRC msg: 0x%016llx (%d bits)\n",
+			msg.msg, msg.bits);
+		return -EAGAIN;
 	}
 
 	if (msgp)
@@ -325,19 +396,23 @@ static int read_one_response(struct fsi_master_gpio *master,
 static int issue_term(struct fsi_master_gpio *master, uint8_t slave)
 {
 	struct fsi_gpio_msg cmd;
+	unsigned long flags;
 	uint8_t tag;
 	int rc;
 
 	build_term_command(&cmd, slave);
+
+	local_irq_save(flags);
 	serial_out(master, &cmd);
 	echo_delay(master);
+	local_irq_restore(flags);
 
 	rc = read_one_response(master, 0, NULL, &tag);
 	if (rc < 0) {
 		dev_err(master->dev,
 				"TERM failed; lost communication with slave\n");
 		return -EIO;
-	} else if (tag != FSI_GPIO_RESP_ACK) {
+	} else if (tag != FSI_RESP_ACK) {
 		dev_err(master->dev, "TERM failed; response %d\n", tag);
 		return -EIO;
 	}
@@ -350,16 +425,39 @@ static int poll_for_response(struct fsi_master_gpio *master,
 {
 	struct fsi_gpio_msg response, cmd;
 	int busy_count = 0, rc, i;
+	unsigned long flags;
 	uint8_t tag;
 	uint8_t *data_byte = data;
-
+	int crc_err_retries = 0;
 retry:
 	rc = read_one_response(master, size, &response, &tag);
-	if (rc)
-		return rc;
+
+	/* Handle retries on CRC errors */
+	if (rc == -EAGAIN) {
+		/* Too many retries ? */
+		if (crc_err_retries++ > FSI_CRC_ERR_RETRIES) {
+			/*
+			 * Pass it up as a -EIO otherwise upper level will retry
+			 * the whole command which isn't what we want here.
+			 */
+			rc = -EIO;
+			goto fail;
+		}
+		dev_dbg(master->dev,
+			 "CRC error retry %d\n", crc_err_retries);
+		trace_fsi_master_gpio_crc_rsp_error(master);
+		build_epoll_command(&cmd, slave);
+		local_irq_save(flags);
+		clock_zeros(master, FSI_MASTER_EPOLL_CLOCKS);
+		serial_out(master, &cmd);
+		echo_delay(master);
+		local_irq_restore(flags);
+		goto retry;
+	} else if (rc)
+		goto fail;
 
 	switch (tag) {
-	case FSI_GPIO_RESP_ACK:
+	case FSI_RESP_ACK:
 		if (size && data) {
 			uint64_t val = response.msg;
 			/* clear crc & mask */
@@ -372,57 +470,89 @@ retry:
 			}
 		}
 		break;
-	case FSI_GPIO_RESP_BUSY:
+	case FSI_RESP_BUSY:
 		/*
 		 * Its necessary to clock slave before issuing
 		 * d-poll, not indicated in the hardware protocol
 		 * spec. < 20 clocks causes slave to hang, 21 ok.
 		 */
-		clock_zeros(master, FSI_GPIO_DPOLL_CLOCKS);
-		if (busy_count++ < FSI_GPIO_MAX_BUSY) {
+		if (busy_count++ < FSI_MASTER_MAX_BUSY) {
 			build_dpoll_command(&cmd, slave);
+			local_irq_save(flags);
+			clock_zeros(master, FSI_MASTER_DPOLL_CLOCKS);
 			serial_out(master, &cmd);
 			echo_delay(master);
+			local_irq_restore(flags);
 			goto retry;
 		}
 		dev_warn(master->dev,
 			"ERR slave is stuck in busy state, issuing TERM\n");
+		local_irq_save(flags);
+		clock_zeros(master, FSI_MASTER_DPOLL_CLOCKS);
+		local_irq_restore(flags);
 		issue_term(master, slave);
 		rc = -EIO;
 		break;
 
-	case FSI_GPIO_RESP_ERRA:
-	case FSI_GPIO_RESP_ERRC:
-		dev_dbg(master->dev, "ERR%c received: 0x%x\n",
-			tag == FSI_GPIO_RESP_ERRA ? 'A' : 'C',
-			(int)response.msg);
-		fsi_master_gpio_error(master, response.msg);
+	case FSI_RESP_ERRA:
+		dev_dbg(master->dev, "ERRA received: 0x%x\n", (int)response.msg);
 		rc = -EIO;
 		break;
+	case FSI_RESP_ERRC:
+		dev_dbg(master->dev, "ERRC received: 0x%x\n", (int)response.msg);
+		trace_fsi_master_gpio_crc_cmd_error(master);
+		rc = -EAGAIN;
+		break;
 	}
 
-	/* Clock the slave enough to be ready for next operation */
-	clock_zeros(master, FSI_GPIO_PRIME_SLAVE_CLOCKS);
+	if (busy_count > 0)
+		trace_fsi_master_gpio_poll_response_busy(master, busy_count);
+ fail:
+	/*
+	 * tSendDelay clocks, avoids signal reflections when switching
+	 * from receive of response back to send of data.
+	 */
+	local_irq_save(flags);
+	clock_zeros(master, master->t_send_delay);
+	local_irq_restore(flags);
+
 	return rc;
 }
 
-static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave,
-		struct fsi_gpio_msg *cmd, size_t resp_len, void *resp)
+static int send_request(struct fsi_master_gpio *master,
+		struct fsi_gpio_msg *cmd)
 {
 	unsigned long flags;
-	int rc;
-
-	spin_lock_irqsave(&master->cmd_lock, flags);
 
-	if (master->external_mode) {
-		spin_unlock_irqrestore(&master->cmd_lock, flags);
+	if (master->external_mode)
 		return -EBUSY;
-	}
 
+	local_irq_save(flags);
 	serial_out(master, cmd);
 	echo_delay(master);
-	rc = poll_for_response(master, slave, resp_len, resp);
-	spin_unlock_irqrestore(&master->cmd_lock, flags);
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+static int fsi_master_gpio_xfer(struct fsi_master_gpio *master, uint8_t slave,
+		struct fsi_gpio_msg *cmd, size_t resp_len, void *resp)
+{
+	int rc = -EAGAIN, retries = 0;
+
+	while ((retries++) < FSI_CRC_ERR_RETRIES) {
+		rc = send_request(master, cmd);
+		if (rc)
+			break;
+		rc = poll_for_response(master, slave, resp_len, resp);
+		if (rc != -EAGAIN)
+			break;
+		rc = -EIO;
+		dev_warn(master->dev, "ECRC retry %d\n", retries);
+
+		/* Pace it a bit before retry */
+		msleep(1);
+	}
 
 	return rc;
 }
@@ -432,12 +562,18 @@ static int fsi_master_gpio_read(struct fsi_master *_master, int link,
 {
 	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
 	struct fsi_gpio_msg cmd;
+	int rc;
 
 	if (link != 0)
 		return -ENODEV;
 
-	build_abs_ar_command(&cmd, id, addr, size, NULL);
-	return fsi_master_gpio_xfer(master, id, &cmd, size, val);
+	mutex_lock(&master->cmd_lock);
+	build_ar_command(master, &cmd, id, addr, size, NULL);
+	rc = fsi_master_gpio_xfer(master, id, &cmd, size, val);
+	last_address_update(master, id, rc == 0, addr);
+	mutex_unlock(&master->cmd_lock);
+
+	return rc;
 }
 
 static int fsi_master_gpio_write(struct fsi_master *_master, int link,
@@ -445,12 +581,18 @@ static int fsi_master_gpio_write(struct fsi_master *_master, int link,
 {
 	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
 	struct fsi_gpio_msg cmd;
+	int rc;
 
 	if (link != 0)
 		return -ENODEV;
 
-	build_abs_ar_command(&cmd, id, addr, size, val);
-	return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	mutex_lock(&master->cmd_lock);
+	build_ar_command(master, &cmd, id, addr, size, val);
+	rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	last_address_update(master, id, rc == 0, addr);
+	mutex_unlock(&master->cmd_lock);
+
+	return rc;
 }
 
 static int fsi_master_gpio_term(struct fsi_master *_master,
@@ -458,12 +600,18 @@ static int fsi_master_gpio_term(struct fsi_master *_master,
 {
 	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
 	struct fsi_gpio_msg cmd;
+	int rc;
 
 	if (link != 0)
 		return -ENODEV;
 
+	mutex_lock(&master->cmd_lock);
 	build_term_command(&cmd, id);
-	return fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	rc = fsi_master_gpio_xfer(master, id, &cmd, 0, NULL);
+	last_address_update(master, id, false, 0);
+	mutex_unlock(&master->cmd_lock);
+
+	return rc;
 }
 
 static int fsi_master_gpio_break(struct fsi_master *_master, int link)
@@ -476,11 +624,14 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link)
 
 	trace_fsi_master_gpio_break(master);
 
-	spin_lock_irqsave(&master->cmd_lock, flags);
+	mutex_lock(&master->cmd_lock);
 	if (master->external_mode) {
-		spin_unlock_irqrestore(&master->cmd_lock, flags);
+		mutex_unlock(&master->cmd_lock);
 		return -EBUSY;
 	}
+
+	local_irq_save(flags);
+
 	set_sda_output(master, 1);
 	sda_out(master, 1);
 	clock_toggle(master, FSI_PRE_BREAK_CLOCKS);
@@ -489,7 +640,11 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link)
 	echo_delay(master);
 	sda_out(master, 1);
 	clock_toggle(master, FSI_POST_BREAK_CLOCKS);
-	spin_unlock_irqrestore(&master->cmd_lock, flags);
+
+	local_irq_restore(flags);
+
+	last_address_update(master, 0, false, 0);
+	mutex_unlock(&master->cmd_lock);
 
 	/* Wait for logic reset to take effect */
 	udelay(200);
@@ -499,6 +654,8 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link)
 
 static void fsi_master_gpio_init(struct fsi_master_gpio *master)
 {
+	unsigned long flags;
+
 	gpiod_direction_output(master->gpio_mux, 1);
 	gpiod_direction_output(master->gpio_trans, 1);
 	gpiod_direction_output(master->gpio_enable, 1);
@@ -506,7 +663,9 @@ static void fsi_master_gpio_init(struct fsi_master_gpio *master)
 	gpiod_direction_output(master->gpio_data, 1);
 
 	/* todo: evaluate if clocks can be reduced */
+	local_irq_save(flags);
 	clock_zeros(master, FSI_INIT_CLOCKS);
+	local_irq_restore(flags);
 }
 
 static void fsi_master_gpio_init_external(struct fsi_master_gpio *master)
@@ -521,22 +680,37 @@ static void fsi_master_gpio_init_external(struct fsi_master_gpio *master)
 static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link)
 {
 	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
-	unsigned long flags;
 	int rc = -EBUSY;
 
 	if (link != 0)
 		return -ENODEV;
 
-	spin_lock_irqsave(&master->cmd_lock, flags);
+	mutex_lock(&master->cmd_lock);
 	if (!master->external_mode) {
 		gpiod_set_value(master->gpio_enable, 1);
 		rc = 0;
 	}
-	spin_unlock_irqrestore(&master->cmd_lock, flags);
+	mutex_unlock(&master->cmd_lock);
 
 	return rc;
 }
 
+static int fsi_master_gpio_link_config(struct fsi_master *_master, int link,
+				       u8 t_send_delay, u8 t_echo_delay)
+{
+	struct fsi_master_gpio *master = to_fsi_master_gpio(_master);
+
+	if (link != 0)
+		return -ENODEV;
+
+	mutex_lock(&master->cmd_lock);
+	master->t_send_delay = t_send_delay;
+	master->t_echo_delay = t_echo_delay;
+	mutex_unlock(&master->cmd_lock);
+
+	return 0;
+}
+
 static ssize_t external_mode_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
@@ -550,7 +724,7 @@ static ssize_t external_mode_store(struct device *dev,
 		struct device_attribute *attr, const char *buf, size_t count)
 {
 	struct fsi_master_gpio *master = dev_get_drvdata(dev);
-	unsigned long flags, val;
+	unsigned long val;
 	bool external_mode;
 	int err;
 
@@ -560,10 +734,10 @@ static ssize_t external_mode_store(struct device *dev,
 
 	external_mode = !!val;
 
-	spin_lock_irqsave(&master->cmd_lock, flags);
+	mutex_lock(&master->cmd_lock);
 
 	if (external_mode == master->external_mode) {
-		spin_unlock_irqrestore(&master->cmd_lock, flags);
+		mutex_unlock(&master->cmd_lock);
 		return count;
 	}
 
@@ -572,7 +746,8 @@ static ssize_t external_mode_store(struct device *dev,
 		fsi_master_gpio_init_external(master);
 	else
 		fsi_master_gpio_init(master);
-	spin_unlock_irqrestore(&master->cmd_lock, flags);
+
+	mutex_unlock(&master->cmd_lock);
 
 	fsi_master_rescan(&master->master);
 
@@ -582,31 +757,44 @@ static ssize_t external_mode_store(struct device *dev,
 static DEVICE_ATTR(external_mode, 0664,
 		external_mode_show, external_mode_store);
 
+static void fsi_master_gpio_release(struct device *dev)
+{
+	struct fsi_master_gpio *master = to_fsi_master_gpio(dev_to_fsi_master(dev));
+
+	of_node_put(dev_of_node(master->dev));
+
+	kfree(master);
+}
+
 static int fsi_master_gpio_probe(struct platform_device *pdev)
 {
 	struct fsi_master_gpio *master;
 	struct gpio_desc *gpio;
 	int rc;
 
-	master = devm_kzalloc(&pdev->dev, sizeof(*master), GFP_KERNEL);
+	master = kzalloc(sizeof(*master), GFP_KERNEL);
 	if (!master)
 		return -ENOMEM;
 
 	master->dev = &pdev->dev;
 	master->master.dev.parent = master->dev;
 	master->master.dev.of_node = of_node_get(dev_of_node(master->dev));
+	master->master.dev.release = fsi_master_gpio_release;
+	master->last_addr = LAST_ADDR_INVALID;
 
 	gpio = devm_gpiod_get(&pdev->dev, "clock", 0);
 	if (IS_ERR(gpio)) {
 		dev_err(&pdev->dev, "failed to get clock gpio\n");
-		return PTR_ERR(gpio);
+		rc = PTR_ERR(gpio);
+		goto err_free;
 	}
 	master->gpio_clk = gpio;
 
 	gpio = devm_gpiod_get(&pdev->dev, "data", 0);
 	if (IS_ERR(gpio)) {
 		dev_err(&pdev->dev, "failed to get data gpio\n");
-		return PTR_ERR(gpio);
+		rc = PTR_ERR(gpio);
+		goto err_free;
 	}
 	master->gpio_data = gpio;
 
@@ -614,24 +802,38 @@ static int fsi_master_gpio_probe(struct platform_device *pdev)
 	gpio = devm_gpiod_get_optional(&pdev->dev, "trans", 0);
 	if (IS_ERR(gpio)) {
 		dev_err(&pdev->dev, "failed to get trans gpio\n");
-		return PTR_ERR(gpio);
+		rc = PTR_ERR(gpio);
+		goto err_free;
 	}
 	master->gpio_trans = gpio;
 
 	gpio = devm_gpiod_get_optional(&pdev->dev, "enable", 0);
 	if (IS_ERR(gpio)) {
 		dev_err(&pdev->dev, "failed to get enable gpio\n");
-		return PTR_ERR(gpio);
+		rc = PTR_ERR(gpio);
+		goto err_free;
 	}
 	master->gpio_enable = gpio;
 
 	gpio = devm_gpiod_get_optional(&pdev->dev, "mux", 0);
 	if (IS_ERR(gpio)) {
 		dev_err(&pdev->dev, "failed to get mux gpio\n");
-		return PTR_ERR(gpio);
+		rc = PTR_ERR(gpio);
+		goto err_free;
 	}
 	master->gpio_mux = gpio;
 
+	/*
+	 * Check if GPIO block is slow enought that no extra delays
+	 * are necessary. This improves performance on ast2500 by
+	 * an order of magnitude.
+	 */
+	master->no_delays = device_property_present(&pdev->dev, "no-gpio-delays");
+
+	/* Default FSI command delays */
+	master->t_send_delay = FSI_SEND_DELAY_CLOCKS;
+	master->t_echo_delay = FSI_ECHO_DELAY_CLOCKS;
+
 	master->master.n_links = 1;
 	master->master.flags = FSI_MASTER_FLAG_SWCLOCK;
 	master->master.read = fsi_master_gpio_read;
@@ -639,34 +841,37 @@ static int fsi_master_gpio_probe(struct platform_device *pdev)
 	master->master.term = fsi_master_gpio_term;
 	master->master.send_break = fsi_master_gpio_break;
 	master->master.link_enable = fsi_master_gpio_link_enable;
+	master->master.link_config = fsi_master_gpio_link_config;
 	platform_set_drvdata(pdev, master);
-	spin_lock_init(&master->cmd_lock);
+	mutex_init(&master->cmd_lock);
 
 	fsi_master_gpio_init(master);
 
 	rc = device_create_file(&pdev->dev, &dev_attr_external_mode);
 	if (rc)
-		return rc;
+		goto err_free;
 
-	return fsi_master_register(&master->master);
+	rc = fsi_master_register(&master->master);
+	if (rc) {
+		device_remove_file(&pdev->dev, &dev_attr_external_mode);
+		put_device(&master->master.dev);
+		return rc;
+	}
+	return 0;
+ err_free:
+	kfree(master);
+	return rc;
 }
 
 
+
 static int fsi_master_gpio_remove(struct platform_device *pdev)
 {
 	struct fsi_master_gpio *master = platform_get_drvdata(pdev);
 
-	devm_gpiod_put(&pdev->dev, master->gpio_clk);
-	devm_gpiod_put(&pdev->dev, master->gpio_data);
-	if (master->gpio_trans)
-		devm_gpiod_put(&pdev->dev, master->gpio_trans);
-	if (master->gpio_enable)
-		devm_gpiod_put(&pdev->dev, master->gpio_enable);
-	if (master->gpio_mux)
-		devm_gpiod_put(&pdev->dev, master->gpio_mux);
-	fsi_master_unregister(&master->master);
+	device_remove_file(&pdev->dev, &dev_attr_external_mode);
 
-	of_node_put(master->master.dev.of_node);
+	fsi_master_unregister(&master->master);
 
 	return 0;
 }