1 files changed, 275 insertions, 114 deletions

diff --git a/drivers/staging/nvec/nvec.c b/drivers/staging/nvec/nvec.c
index 8e97e2d7ac3..1a120c1418e 100644
--- a/drivers/staging/nvec/nvec.c
+++ b/drivers/staging/nvec/nvec.c
@@ -155,27 +155,81 @@ static void nvec_gpio_set_value(struct nvec_chip *nvec, int value)
 void nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
 			short size)
 {
-	struct nvec_msg *msg = kzalloc(sizeof(struct nvec_msg), GFP_NOWAIT);
+	struct nvec_msg *msg;
+	unsigned long flags;
 
-	msg->data = kzalloc(size, GFP_NOWAIT);
+	msg = nvec_msg_alloc(nvec);
 	msg->data[0] = size;
 	memcpy(msg->data + 1, data, size);
 	msg->size = size + 1;
-	msg->pos = 0;
-	INIT_LIST_HEAD(&msg->node);
 
+	spin_lock_irqsave(&nvec->tx_lock, flags);
 	list_add_tail(&msg->node, &nvec->tx_data);
+	spin_unlock_irqrestore(&nvec->tx_lock, flags);
 
-	gpio_set_value(nvec->gpio, 0);
+	queue_work(nvec->wq, &nvec->tx_work);
 }
 EXPORT_SYMBOL(nvec_write_async);
 
+struct nvec_msg *nvec_write_sync(struct nvec_chip *nvec,
+		const unsigned char *data, short size)
+{
+	struct nvec_msg *msg;
+
+	mutex_lock(&nvec->sync_write_mutex);
+
+	nvec->sync_write_pending = (data[1] << 8) + data[0];
+	nvec_write_async(nvec, data, size);
+
+	dev_dbg(nvec->dev, "nvec_sync_write: 0x%04x\n",
+					nvec->sync_write_pending);
+	if (!(wait_for_completion_timeout(&nvec->sync_write,
+				msecs_to_jiffies(2000)))) {
+		dev_warn(nvec->dev, "timeout waiting for sync write to complete\n");
+		mutex_unlock(&nvec->sync_write_mutex);
+		return NULL;
+	}
+
+	dev_dbg(nvec->dev, "nvec_sync_write: pong!\n");
+
+	msg = nvec->last_sync_msg;
+
+	mutex_unlock(&nvec->sync_write_mutex);
+
+	return msg;
+}
+EXPORT_SYMBOL(nvec_write_sync);
+
+/* TX worker */
 static void nvec_request_master(struct work_struct *work)
 {
 	struct nvec_chip *nvec = container_of(work, struct nvec_chip, tx_work);
+	unsigned long flags;
+	long err;
+	struct nvec_msg *msg;
+
+	spin_lock_irqsave(&nvec->tx_lock, flags);
+	while (!list_empty(&nvec->tx_data)) {
+		msg = list_first_entry(&nvec->tx_data, struct nvec_msg, node);
+		spin_unlock_irqrestore(&nvec->tx_lock, flags);
+		nvec_gpio_set_value(nvec, 0);
+		err = wait_for_completion_interruptible_timeout(
+				&nvec->ec_transfer, msecs_to_jiffies(5000));
+
+		if (err == 0) {
+			dev_warn(nvec->dev, "timeout waiting for ec transfer\n");
+			nvec_gpio_set_value(nvec, 1);
+			msg->pos = 0;
+		}
 
-	if (!list_empty(&nvec->tx_data))
-		gpio_set_value(nvec->gpio, 0);
+		spin_lock_irqsave(&nvec->tx_lock, flags);
+
+		if (err > 0) {
+			list_del_init(&msg->node);
+			nvec_msg_free(nvec, msg);
+		}
+	}
+	spin_unlock_irqrestore(&nvec->tx_lock, flags);
 }
 
 static int parse_msg(struct nvec_chip *nvec, struct nvec_msg *msg)
@@ -197,143 +251,243 @@ static int parse_msg(struct nvec_chip *nvec, struct nvec_msg *msg)
 	return 0;
 }
 
-static struct nvec_msg *nvec_write_sync(struct nvec_chip *nvec,
-					const unsigned char *data, short size)
-{
-	down(&nvec->sync_write_mutex);
-
-	nvec->sync_write_pending = (data[1] << 8) + data[0];
-	nvec_write_async(nvec, data, size);
-
-	dev_dbg(nvec->dev, "nvec_sync_write: 0x%04x\n",
-		nvec->sync_write_pending);
-	wait_for_completion(&nvec->sync_write);
-	dev_dbg(nvec->dev, "nvec_sync_write: pong!\n");
-
-	up(&nvec->sync_write_mutex);
-
-	return nvec->last_sync_msg;
-}
-
 /* RX worker */
 static void nvec_dispatch(struct work_struct *work)
 {
 	struct nvec_chip *nvec = container_of(work, struct nvec_chip, rx_work);
+	unsigned long flags;
 	struct nvec_msg *msg;
 
+	spin_lock_irqsave(&nvec->rx_lock, flags);
 	while (!list_empty(&nvec->rx_data)) {
 		msg = list_first_entry(&nvec->rx_data, struct nvec_msg, node);
 		list_del_init(&msg->node);
+		spin_unlock_irqrestore(&nvec->rx_lock, flags);
 
 		if (nvec->sync_write_pending ==
-		    (msg->data[2] << 8) + msg->data[0]) {
+		      (msg->data[2] << 8) + msg->data[0]) {
 			dev_dbg(nvec->dev, "sync write completed!\n");
 			nvec->sync_write_pending = 0;
 			nvec->last_sync_msg = msg;
 			complete(&nvec->sync_write);
 		} else {
 			parse_msg(nvec, msg);
-			if ((!msg) || (!msg->data))
-				dev_warn(nvec->dev,
-					"attempt access zero pointer\n");
-			else {
-				kfree(msg->data);
-				kfree(msg);
-			}
+			nvec_msg_free(nvec, msg);
 		}
+		spin_lock_irqsave(&nvec->rx_lock, flags);
 	}
+	spin_unlock_irqrestore(&nvec->rx_lock, flags);
 }
 
+static void nvec_tx_completed(struct nvec_chip *nvec)
+{
+	/* We got an END_TRANS, let's skip this, maybe there's an event */
+	if (nvec->tx->pos != nvec->tx->size) {
+		dev_err(nvec->dev, "premature END_TRANS, resending\n");
+		nvec->tx->pos = 0;
+		nvec_gpio_set_value(nvec, 0);
+	} else {
+		nvec->state = 0;
+	}
+}
+
+static void nvec_rx_completed(struct nvec_chip *nvec)
+{
+	if (nvec->rx->pos != nvec_msg_size(nvec->rx))
+		dev_err(nvec->dev, "RX incomplete: Expected %u bytes, got %u\n",
+			   (uint) nvec_msg_size(nvec->rx),
+			   (uint) nvec->rx->pos);
+
+	spin_lock(&nvec->rx_lock);
+
+	/* add the received data to the work list
+	   and move the ring buffer pointer to the next entry */
+	list_add_tail(&nvec->rx->node, &nvec->rx_data);
+
+	spin_unlock(&nvec->rx_lock);
+
+	nvec->state = 0;
+
+	if (!nvec_msg_is_event(nvec->rx))
+		complete(&nvec->ec_transfer);
+
+	queue_work(nvec->wq, &nvec->rx_work);
+}
+
+/**
+ * nvec_invalid_flags - Send an error message about invalid flags and jump
+ * @nvec: The nvec device
+ * @status: The status flags
+ * @reset: Whether we shall jump to state 0.
+ */
+static void nvec_invalid_flags(struct nvec_chip *nvec, unsigned int status,
+			       bool reset)
+{
+	dev_err(nvec->dev, "unexpected status flags 0x%02x during state %i\n",
+		status, nvec->state);
+	if (reset)
+		nvec->state = 0;
+}
+
+/**
+ * nvec_tx_set - Set the message to transfer (nvec->tx)
+ */
+static void nvec_tx_set(struct nvec_chip *nvec)
+{
+	spin_lock(&nvec->tx_lock);
+	if (list_empty(&nvec->tx_data)) {
+		dev_err(nvec->dev, "empty tx - sending no-op\n");
+		memcpy(nvec->tx_scratch.data, "\x02\x07\x02", 3);
+		nvec->tx_scratch.size = 3;
+		nvec->tx_scratch.pos = 0;
+		nvec->tx = &nvec->tx_scratch;
+		list_add_tail(&nvec->tx->node, &nvec->tx_data);
+	} else {
+		nvec->tx = list_first_entry(&nvec->tx_data, struct nvec_msg,
+					    node);
+		nvec->tx->pos = 0;
+	}
+	spin_unlock(&nvec->tx_lock);
+
+	dev_dbg(nvec->dev, "Sending message of length %u, command 0x%x\n",
+		(uint)nvec->tx->size, nvec->tx->data[1]);
+}
+
+/**
+ * nvec_interrupt - Interrupt handler
+ * @irq: The IRQ
+ * @dev: The nvec device
+ */
 static irqreturn_t nvec_interrupt(int irq, void *dev)
 {
 	unsigned long status;
-	unsigned long received;
-	unsigned char to_send;
-	struct nvec_msg *msg;
-	struct nvec_chip *nvec = (struct nvec_chip *)dev;
-	void __iomem *base = nvec->base;
+	unsigned int received = 0;
+	unsigned char to_send = 0xff;
+	const unsigned long irq_mask = I2C_SL_IRQ | END_TRANS | RCVD | RNW;
+	struct nvec_chip *nvec = dev;
+	unsigned int state = nvec->state;
 
-	status = readl(base + I2C_SL_STATUS);
+	status = readl(nvec->base + I2C_SL_STATUS);
 
-	if (!(status & I2C_SL_IRQ)) {
-		dev_warn(nvec->dev, "nvec Spurious IRQ\n");
-		goto handled;
+	/* Filter out some errors */
+	if ((status & irq_mask) == 0 && (status & ~irq_mask) != 0) {
+		dev_err(nvec->dev, "unexpected irq mask %lx\n", status);
+		return IRQ_HANDLED;
 	}
-	if (status & END_TRANS && !(status & RCVD)) {
-		nvec->state = NVEC_WAIT;
-		if (nvec->rx->size > 1) {
-			list_add_tail(&nvec->rx->node, &nvec->rx_data);
-			schedule_work(&nvec->rx_work);
-		} else {
-			kfree(nvec->rx->data);
-			kfree(nvec->rx);
-		}
+	if ((status & I2C_SL_IRQ) == 0) {
+		dev_err(nvec->dev, "Spurious IRQ\n");
 		return IRQ_HANDLED;
-	} else if (status & RNW) {
-		if (status & RCVD)
-			udelay(3);
+	}
 
+	/* The EC did not request a read, so it send us something, read it */
+	if ((status & RNW) == 0) {
+		received = readl(nvec->base + I2C_SL_RCVD);
 		if (status & RCVD)
-			nvec->state = NVEC_WRITE;
+			writel(0, nvec->base + I2C_SL_RCVD);
+	}
 
-		if (list_empty(&nvec->tx_data)) {
-			dev_err(nvec->dev, "nvec empty tx - sending no-op\n");
-			to_send = 0x8a;
-			nvec_write_async(nvec, "\x07\x02", 2);
+	if (status == (I2C_SL_IRQ | RCVD))
+		nvec->state = 0;
+
+	switch (nvec->state) {
+	case 0:		/* Verify that its a transfer start, the rest later */
+		if (status != (I2C_SL_IRQ | RCVD))
+			nvec_invalid_flags(nvec, status, false);
+		break;
+	case 1:		/* command byte */
+		if (status != I2C_SL_IRQ) {
+			nvec_invalid_flags(nvec, status, true);
 		} else {
-			msg =
-			    list_first_entry(&nvec->tx_data, struct nvec_msg,
-					     node);
-			if (msg->pos < msg->size) {
-				to_send = msg->data[msg->pos];
-				msg->pos++;
-			} else {
-				dev_err(nvec->dev, "nvec crap! %d\n",
-					msg->size);
-				to_send = 0x01;
-			}
-
-			if (msg->pos >= msg->size) {
-				list_del_init(&msg->node);
-				kfree(msg->data);
-				kfree(msg);
-				schedule_work(&nvec->tx_work);
-				nvec->state = NVEC_WAIT;
+			nvec->rx = nvec_msg_alloc(nvec);
+			nvec->rx->data[0] = received;
+			nvec->rx->pos = 1;
+			nvec->state = 2;
+		}
+		break;
+	case 2:		/* first byte after command */
+		if (status == (I2C_SL_IRQ | RNW | RCVD)) {
+			udelay(33);
+			if (nvec->rx->data[0] != 0x01) {
+				dev_err(nvec->dev,
+					"Read without prior read command\n");
+				nvec->state = 0;
+				break;
 			}
+			nvec_msg_free(nvec, nvec->rx);
+			nvec->state = 3;
+			nvec_tx_set(nvec);
+			BUG_ON(nvec->tx->size < 1);
+			to_send = nvec->tx->data[0];
+			nvec->tx->pos = 1;
+		} else if (status == (I2C_SL_IRQ)) {
+			BUG_ON(nvec->rx == NULL);
+			nvec->rx->data[1] = received;
+			nvec->rx->pos = 2;
+			nvec->state = 4;
+		} else {
+			nvec_invalid_flags(nvec, status, true);
 		}
-		writel(to_send, base + I2C_SL_RCVD);
-
-		gpio_set_value(nvec->gpio, 1);
-
-		dev_dbg(nvec->dev, "nvec sent %x\n", to_send);
-
-		goto handled;
-	} else {
-		received = readl(base + I2C_SL_RCVD);
-
-		if (status & RCVD) {
-			writel(0, base + I2C_SL_RCVD);
-			goto handled;
+		break;
+	case 3:		/* EC does a block read, we transmit data */
+		if (status & END_TRANS) {
+			nvec_tx_completed(nvec);
+		} else if ((status & RNW) == 0 || (status & RCVD)) {
+			nvec_invalid_flags(nvec, status, true);
+		} else if (nvec->tx && nvec->tx->pos < nvec->tx->size) {
+			to_send = nvec->tx->data[nvec->tx->pos++];
+		} else {
+			dev_err(nvec->dev, "tx buffer underflow on %p (%u > %u)\n",
+				nvec->tx,
+				(uint) (nvec->tx ? nvec->tx->pos : 0),
+				(uint) (nvec->tx ? nvec->tx->size : 0));
+			nvec->state = 0;
 		}
+		break;
+	case 4:		/* EC does some write, we read the data */
+		if ((status & (END_TRANS | RNW)) == END_TRANS)
+			nvec_rx_completed(nvec);
+		else if (status & (RNW | RCVD))
+			nvec_invalid_flags(nvec, status, true);
+		else if (nvec->rx && nvec->rx->pos < NVEC_MSG_SIZE)
+			nvec->rx->data[nvec->rx->pos++] = received;
+		else
+			dev_err(nvec->dev,
+				"RX buffer overflow on %p: "
+				"Trying to write byte %u of %u\n",
+				nvec->rx, nvec->rx->pos, NVEC_MSG_SIZE);
+		break;
+	default:
+		nvec->state = 0;
+	}
 
-		if (nvec->state == NVEC_WAIT) {
-			nvec->state = NVEC_READ;
-			msg = kzalloc(sizeof(struct nvec_msg), GFP_NOWAIT);
-			msg->data = kzalloc(32, GFP_NOWAIT);
-			INIT_LIST_HEAD(&msg->node);
-			nvec->rx = msg;
-		} else
-			msg = nvec->rx;
-
-		BUG_ON(msg->pos > 32);
-
-		msg->data[msg->pos] = received;
-		msg->pos++;
-		msg->size = msg->pos;
-		dev_dbg(nvec->dev, "Got %02lx from Master (pos: %d)!\n",
-			received, msg->pos);
+	/* If we are told that a new transfer starts, verify it */
+	if ((status & (RCVD | RNW)) == RCVD) {
+		if (received != nvec->i2c_addr)
+			dev_err(nvec->dev,
+			"received address 0x%02x, expected 0x%02x\n",
+			received, nvec->i2c_addr);
+		nvec->state = 1;
 	}
-handled:
+
+	/* Send data if requested, but not on end of transmission */
+	if ((status & (RNW | END_TRANS)) == RNW)
+		writel(to_send, nvec->base + I2C_SL_RCVD);
+
+	/* If we have send the first byte */
+	if (status == (I2C_SL_IRQ | RNW | RCVD))
+		nvec_gpio_set_value(nvec, 1);
+
+	dev_dbg(nvec->dev,
+		"Handled: %s 0x%02x, %s 0x%02x in state %u [%s%s%s]\n",
+		(status & RNW) == 0 ? "received" : "R=",
+		received,
+		(status & (RNW | END_TRANS)) ? "sent" : "S=",
+		to_send,
+		state,
+		status & END_TRANS ? " END_TRANS" : "",
+		status & RCVD ? " RCVD" : "",
+		status & RNW ? " RNW" : "");
+
 	return IRQ_HANDLED;
 }
 
@@ -432,6 +586,7 @@ static int __devinit tegra_nvec_probe(struct platform_device *pdev)
 	nvec->base = base;
 	nvec->irq = res->start;
 	nvec->i2c_clk = i2c_clk;
+	nvec->rx = &nvec->msg_pool[0];
 
 	/* Set the gpio to low when we've got something to say */
 	err = gpio_request(nvec->gpio, "nvec gpio");
@@ -441,11 +596,15 @@ static int __devinit tegra_nvec_probe(struct platform_device *pdev)
 	ATOMIC_INIT_NOTIFIER_HEAD(&nvec->notifier_list);
 
 	init_completion(&nvec->sync_write);
-	sema_init(&nvec->sync_write_mutex, 1);
-	INIT_LIST_HEAD(&nvec->tx_data);
+	init_completion(&nvec->ec_transfer);
+	mutex_init(&nvec->sync_write_mutex);
+	spin_lock_init(&nvec->tx_lock);
+	spin_lock_init(&nvec->rx_lock);
 	INIT_LIST_HEAD(&nvec->rx_data);
+	INIT_LIST_HEAD(&nvec->tx_data);
 	INIT_WORK(&nvec->rx_work, nvec_dispatch);
 	INIT_WORK(&nvec->tx_work, nvec_request_master);
+	nvec->wq = alloc_workqueue("nvec", WQ_NON_REENTRANT, 2);
 
 	err = request_irq(nvec->irq, nvec_interrupt, 0, "nvec", nvec);
 	if (err) {
@@ -473,13 +632,14 @@ static int __devinit tegra_nvec_probe(struct platform_device *pdev)
 
 	/* Get Firmware Version */
 	msg = nvec_write_sync(nvec, EC_GET_FIRMWARE_VERSION,
-			      sizeof(EC_GET_FIRMWARE_VERSION));
+		sizeof(EC_GET_FIRMWARE_VERSION));
 
-	dev_warn(nvec->dev, "ec firmware version %02x.%02x.%02x / %02x\n",
-		 msg->data[4], msg->data[5], msg->data[6], msg->data[7]);
+	if (msg) {
+		dev_warn(nvec->dev, "ec firmware version %02x.%02x.%02x / %02x\n",
+			msg->data[4], msg->data[5], msg->data[6], msg->data[7]);
 
-	kfree(msg->data);
-	kfree(msg);
+		nvec_msg_free(nvec, msg);
+	}
 
 	ret = mfd_add_devices(nvec->dev, -1, nvec_devices,
 			      ARRAY_SIZE(nvec_devices), base, 0);
@@ -513,6 +673,7 @@ static int __devexit tegra_nvec_remove(struct platform_device *pdev)
 	free_irq(nvec->irq, &nvec_interrupt);
 	iounmap(nvec->base);
 	gpio_free(nvec->gpio);
+	destroy_workqueue(nvec->wq);
 	kfree(nvec);
 
 	return 0;