Merge tag 'isci-for-3.5' into misc

isci update for 3.5

1/ Rework remote-node-context (RNC) handling for proper management of
   the silicon state machine in error handling and hot-plug conditions.
   Further details below, suffice to say if the RNC is mismanaged the
   silicon state machines may lock up.

2/ Refactor the initialization code to be reused for suspend/resume support

3/ Miscellaneous bug fixes to address discovery issues and hardware
   compatibility.

RNC rework details from Jeff Skirvin:

In the controller, devices as they appear on a SAS domain (or
direct-attached SATA devices) are represented by memory structures known
as "Remote Node Contexts" (RNCs).  These structures are transferred from
main memory to the controller using a set of register commands; these
commands include setting up the context ("posting"), removing the
context ("invalidating"), and commands to control the scheduling of
commands and connections to that remote device ("suspensions" and
"resumptions").  There is a similar path to control RNC scheduling from
the protocol engine, which interprets the results of command and data
transmission and reception.

In general, the controller chooses among non-suspended RNCs to find one
that has work requiring scheduling the transmission of command and data
frames to a target.  Likewise, when a target tries to return data back
to the initiator, the state of the RNC is used by the controller to
determine how to treat the incoming request. As an example, if the RNC
is in the state "TX/RX Suspended", incoming SSP connection requests from
the target will be rejected by the controller hardware.  When an RNC is
"TX Suspended", it will not be selected by the controller hardware to
start outgoing command or data operations (with certain priority-based
exceptions).

As mentioned above, there are two sources for management of the RNC
states: commands from driver software, and the result of transmission
and reception conditions of commands and data signaled by the controller
hardware.  As an example of the latter, if an outgoing SSP command ends
with a OPEN_REJECT(BAD_DESTINATION) status, the RNC state will
transition to the "TX Suspended" state, and this is signaled by the
controller hardware in the status to the completion of the pending
command as well as signaled in a controller hardware event.  Examples of
the former are included in the patch changelogs.

Driver software is required to suspend the RNC in a "TX/RX Suspended"
condition before any outstanding commands can be terminated.  Failure to
guarantee this can lead to a complete hardware hang condition.  Earlier
versions of the driver software did not guarantee that an RNC was
correctly managed before I/O termination, and so operated in an unsafe
way.

Further, the driver performed unnecessary contortions to preserve the
remote device command state and so was more complicated than it needed
to be.  A simplifying driver assumption is that once an I/O has entered
the error handler path without having completed in the target, the
requirement on the driver is that all use of the sas_task must end.
Beyond that, recovery of operation is dependent on libsas and other
components to reset, rediscover and reconfigure the device before normal
operation can restart.  In the driver, this simplifying assumption meant
that the RNC management could be reduced to entry into the suspended
state, terminating the targeted I/O request, and resuming the RNC as
needed for device-specific management such as an SSP Abort Task or LUN
Reset Management request.

1 files changed, 92 insertions, 71 deletions

diff --git a/drivers/spi/spi-bcm63xx.c b/drivers/spi/spi-bcm63xx.c
index f01b2648452e..7491971139a6 100644
--- a/drivers/spi/spi-bcm63xx.c
+++ b/drivers/spi/spi-bcm63xx.c
@@ -1,7 +1,7 @@
 /*
  * Broadcom BCM63xx SPI controller support
  *
- * Copyright (C) 2009-2011 Florian Fainelli <florian@openwrt.org>
+ * Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
  * Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
  *
  * This program is free software; you can redistribute it and/or
@@ -30,6 +30,8 @@
 #include <linux/spi/spi.h>
 #include <linux/completion.h>
 #include <linux/err.h>
+#include <linux/workqueue.h>
+#include <linux/pm_runtime.h>
 
 #include <bcm63xx_dev_spi.h>
 
@@ -37,8 +39,6 @@
 #define DRV_VER		"0.1.2"
 
 struct bcm63xx_spi {
-	spinlock_t		lock;
-	int			stopping;
 	struct completion	done;
 
 	void __iomem		*regs;
@@ -96,17 +96,12 @@ static const unsigned bcm63xx_spi_freq_table[SPI_CLK_MASK][2] = {
 	{   391000, SPI_CLK_0_391MHZ }
 };
 
-static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
-				      struct spi_transfer *t)
+static int bcm63xx_spi_check_transfer(struct spi_device *spi,
+					struct spi_transfer *t)
 {
-	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
 	u8 bits_per_word;
-	u8 clk_cfg, reg;
-	u32 hz;
-	int i;
 
 	bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
-	hz = (t) ? t->speed_hz : spi->max_speed_hz;
 	if (bits_per_word != 8) {
 		dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
 			__func__, bits_per_word);
@@ -119,6 +114,19 @@ static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
 		return -EINVAL;
 	}
 
+	return 0;
+}
+
+static void bcm63xx_spi_setup_transfer(struct spi_device *spi,
+				      struct spi_transfer *t)
+{
+	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+	u32 hz;
+	u8 clk_cfg, reg;
+	int i;
+
+	hz = (t) ? t->speed_hz : spi->max_speed_hz;
+
 	/* Find the closest clock configuration */
 	for (i = 0; i < SPI_CLK_MASK; i++) {
 		if (hz <= bcm63xx_spi_freq_table[i][0]) {
@@ -139,8 +147,6 @@ static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
 	bcm_spi_writeb(bs, reg, SPI_CLK_CFG);
 	dev_dbg(&spi->dev, "Setting clock register to %02x (hz %d)\n",
 		clk_cfg, hz);
-
-	return 0;
 }
 
 /* the spi->mode bits understood by this driver: */
@@ -153,9 +159,6 @@ static int bcm63xx_spi_setup(struct spi_device *spi)
 
 	bs = spi_master_get_devdata(spi->master);
 
-	if (bs->stopping)
-		return -ESHUTDOWN;
-
 	if (!spi->bits_per_word)
 		spi->bits_per_word = 8;
 
@@ -165,7 +168,7 @@ static int bcm63xx_spi_setup(struct spi_device *spi)
 		return -EINVAL;
 	}
 
-	ret = bcm63xx_spi_setup_transfer(spi, NULL);
+	ret = bcm63xx_spi_check_transfer(spi, NULL);
 	if (ret < 0) {
 		dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
 			spi->mode & ~MODEBITS);
@@ -190,28 +193,29 @@ static void bcm63xx_spi_fill_tx_fifo(struct bcm63xx_spi *bs)
 	bs->remaining_bytes -= size;
 }
 
-static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
+static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi,
+					struct spi_transfer *t)
 {
 	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
 	u16 msg_ctl;
 	u16 cmd;
 
+	/* Disable the CMD_DONE interrupt */
+	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+
 	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
 		t->tx_buf, t->rx_buf, t->len);
 
 	/* Transmitter is inhibited */
 	bs->tx_ptr = t->tx_buf;
 	bs->rx_ptr = t->rx_buf;
-	init_completion(&bs->done);
 
 	if (t->tx_buf) {
 		bs->remaining_bytes = t->len;
 		bcm63xx_spi_fill_tx_fifo(bs);
 	}
 
-	/* Enable the command done interrupt which
-	 * we use to determine completion of a command */
-	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+	init_completion(&bs->done);
 
 	/* Fill in the Message control register */
 	msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT);
@@ -230,33 +234,76 @@ static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
 	cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
 	cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
 	bcm_spi_writew(bs, cmd, SPI_CMD);
-	wait_for_completion(&bs->done);
 
-	/* Disable the CMD_DONE interrupt */
-	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+	/* Enable the CMD_DONE interrupt */
+	bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
 
 	return t->len - bs->remaining_bytes;
 }
 
-static int bcm63xx_transfer(struct spi_device *spi, struct spi_message *m)
+static int bcm63xx_spi_prepare_transfer(struct spi_master *master)
 {
-	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
-	struct spi_transfer *t;
-	int ret = 0;
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
 
-	if (unlikely(list_empty(&m->transfers)))
-		return -EINVAL;
+	pm_runtime_get_sync(&bs->pdev->dev);
 
-	if (bs->stopping)
-		return -ESHUTDOWN;
+	return 0;
+}
+
+static int bcm63xx_spi_unprepare_transfer(struct spi_master *master)
+{
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+
+	pm_runtime_put(&bs->pdev->dev);
+
+	return 0;
+}
+
+static int bcm63xx_spi_transfer_one(struct spi_master *master,
+					struct spi_message *m)
+{
+	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+	struct spi_transfer *t;
+	struct spi_device *spi = m->spi;
+	int status = 0;
+	unsigned int timeout = 0;
 
 	list_for_each_entry(t, &m->transfers, transfer_list) {
-		ret += bcm63xx_txrx_bufs(spi, t);
-	}
+		unsigned int len = t->len;
+		u8 rx_tail;
 
-	m->complete(m->context);
+		status = bcm63xx_spi_check_transfer(spi, t);
+		if (status < 0)
+			goto exit;
 
-	return ret;
+		/* configure adapter for a new transfer */
+		bcm63xx_spi_setup_transfer(spi, t);
+
+		while (len) {
+			/* send the data */
+			len -= bcm63xx_txrx_bufs(spi, t);
+
+			timeout = wait_for_completion_timeout(&bs->done, HZ);
+			if (!timeout) {
+				status = -ETIMEDOUT;
+				goto exit;
+			}
+
+			/* read out all data */
+			rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
+
+			/* Read out all the data */
+			if (rx_tail)
+				memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail);
+		}
+
+		m->actual_length += t->len;
+	}
+exit:
+	m->status = status;
+	spi_finalize_current_message(master);
+
+	return 0;
 }
 
 /* This driver supports single master mode only. Hence
@@ -267,39 +314,15 @@ static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
 	struct spi_master *master = (struct spi_master *)dev_id;
 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
 	u8 intr;
-	u16 cmd;
 
 	/* Read interupts and clear them immediately */
 	intr = bcm_spi_readb(bs, SPI_INT_STATUS);
 	bcm_spi_writeb(bs, SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
 
-	/* A tansfer completed */
-	if (intr & SPI_INTR_CMD_DONE) {
-		u8 rx_tail;
-
-		rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
-
-		/* Read out all the data */
-		if (rx_tail)
-			memcpy_fromio(bs->rx_ptr, bs->rx_io, rx_tail);
-
-		/* See if there is more data to send */
-		if (bs->remaining_bytes > 0) {
-			bcm63xx_spi_fill_tx_fifo(bs);
-
-			/* Start the transfer */
-			bcm_spi_writew(bs, SPI_HD_W << SPI_MSG_TYPE_SHIFT,
-				       SPI_MSG_CTL);
-			cmd = bcm_spi_readw(bs, SPI_CMD);
-			cmd |= SPI_CMD_START_IMMEDIATE;
-			cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
-			bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
-			bcm_spi_writew(bs, cmd, SPI_CMD);
-		} else {
-			complete(&bs->done);
-		}
-	}
+	/* A transfer completed */
+	if (intr & SPI_INTR_CMD_DONE)
+		complete(&bs->done);
 
 	return IRQ_HANDLED;
 }
@@ -345,7 +368,6 @@ static int __devinit bcm63xx_spi_probe(struct platform_device *pdev)
 	}
 
 	bs = spi_master_get_devdata(master);
-	init_completion(&bs->done);
 
 	platform_set_drvdata(pdev, master);
 	bs->pdev = pdev;
@@ -379,12 +401,13 @@ static int __devinit bcm63xx_spi_probe(struct platform_device *pdev)
 	master->bus_num = pdata->bus_num;
 	master->num_chipselect = pdata->num_chipselect;
 	master->setup = bcm63xx_spi_setup;
-	master->transfer = bcm63xx_transfer;
+	master->prepare_transfer_hardware = bcm63xx_spi_prepare_transfer;
+	master->unprepare_transfer_hardware = bcm63xx_spi_unprepare_transfer;
+	master->transfer_one_message = bcm63xx_spi_transfer_one;
+	master->mode_bits = MODEBITS;
 	bs->speed_hz = pdata->speed_hz;
-	bs->stopping = 0;
 	bs->tx_io = (u8 *)(bs->regs + bcm63xx_spireg(SPI_MSG_DATA));
 	bs->rx_io = (const u8 *)(bs->regs + bcm63xx_spireg(SPI_RX_DATA));
-	spin_lock_init(&bs->lock);
 
 	/* Initialize hardware */
 	clk_enable(bs->clk);
@@ -418,18 +441,16 @@ static int __devexit bcm63xx_spi_remove(struct platform_device *pdev)
 	struct spi_master *master = platform_get_drvdata(pdev);
 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
 
+	spi_unregister_master(master);
+
 	/* reset spi block */
 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
-	spin_lock(&bs->lock);
-	bs->stopping = 1;
 
 	/* HW shutdown */
 	clk_disable(bs->clk);
 	clk_put(bs->clk);
 
-	spin_unlock(&bs->lock);
 	platform_set_drvdata(pdev, 0);
-	spi_unregister_master(master);
 
 	return 0;
 }