bcm63xx: add support for linux 3.8

Based on 3.8-rc6

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@35482 3c298f89-4303-0410-b956-a3cf2f4a3e73

1 files changed, 240 insertions, 0 deletions

diff --git a/target/linux/brcm63xx/patches-3.8/107-spi-bcm63xx-fix-multi-transfer-messages.patch b/target/linux/brcm63xx/patches-3.8/107-spi-bcm63xx-fix-multi-transfer-messages.patch
new file mode 100644
index 0000000000..85b8524de1
--- /dev/null
+++ b/target/linux/brcm63xx/patches-3.8/107-spi-bcm63xx-fix-multi-transfer-messages.patch
@@ -0,0 +1,240 @@
+From 725e81d507b1098cd275d4e3333c77c4b750fa79 Mon Sep 17 00:00:00 2001
+From: Jonas Gorski <jogo@openwrt.org>
+Date: Sun, 9 Dec 2012 01:53:05 +0100
+Subject: [PATCH V2 2/2] spi/bcm63xx: work around inability to keep CS up
+
+This SPI controller does not support keeping CS asserted after sending
+a transfer.
+Since messages expected on this SPI controller are rather short, we can
+work around it for normal use cases by sending all transfers at once in
+a big full duplex stream.
+
+This means that we cannot change the speed between transfers if they
+require CS to be kept asserted, but these would have been rejected
+before anyway because of the inability of keeping CS asserted.
+
+Signed-off-by: Jonas Gorski <jogo@openwrt.org>
+---
+V1 -> V2:
+ * split out rejection logic into separate patch
+ * fixed return type of bcm63xx_txrx_bufs()
+ * slightly reworked bcm63xx_txrx_bufs, obsoleting one local variable
+
+ drivers/spi/spi-bcm63xx.c |  134 +++++++++++++++++++++++++++++++++++----------
+ 1 file changed, 106 insertions(+), 28 deletions(-)
+
+--- a/drivers/spi/spi-bcm63xx.c
++++ b/drivers/spi/spi-bcm63xx.c
+@@ -37,6 +37,8 @@
+ 
+ #define PFX		KBUILD_MODNAME
+ 
++#define BCM63XX_SPI_MAX_PREPEND		15
++
+ struct bcm63xx_spi {
+ 	struct completion	done;
+ 
+@@ -169,13 +171,17 @@ static int bcm63xx_spi_setup(struct spi_
+ 	return 0;
+ }
+ 
+-static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
++static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *first,
++				unsigned int num_transfers)
+ {
+ 	struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
+ 	u16 msg_ctl;
+ 	u16 cmd;
+ 	u8 rx_tail;
+-	unsigned int timeout = 0;
++	unsigned int i, timeout = 0, prepend_len = 0, len = 0;
++	struct spi_transfer *t = first;
++	bool do_rx = false;
++	bool do_tx = false;
+ 
+ 	/* Disable the CMD_DONE interrupt */
+ 	bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+@@ -183,19 +189,45 @@ static int bcm63xx_txrx_bufs(struct spi_
+ 	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
+ 		t->tx_buf, t->rx_buf, t->len);
+ 
+-	if (t->tx_buf)
+-		memcpy_toio(bs->tx_io, t->tx_buf, t->len);
++	if (num_transfers > 1 && t->tx_buf && t->len <= BCM63XX_SPI_MAX_PREPEND)
++		prepend_len = t->len;
++
++	/* prepare the buffer */
++	for (i = 0; i < num_transfers; i++) {
++		if (t->tx_buf) {
++			do_tx = true;
++			memcpy_toio(bs->tx_io + len, t->tx_buf, t->len);
++
++			/* don't prepend more than one tx */
++			if (t != first)
++				prepend_len = 0;
++		}
++
++		if (t->rx_buf) {
++			do_rx = true;
++			/* prepend is half-duplex write only */
++			if (t == first)
++				prepend_len = 0;
++		}
++
++		len += t->len;
++
++		t = list_entry(t->transfer_list.next, struct spi_transfer,
++			       transfer_list);
++	}
++
++	len -= prepend_len;
+ 
+ 	init_completion(&bs->done);
+ 
+ 	/* Fill in the Message control register */
+-	msg_ctl = (t->len << SPI_BYTE_CNT_SHIFT);
++	msg_ctl = (len << SPI_BYTE_CNT_SHIFT);
+ 
+-	if (t->rx_buf && t->tx_buf)
++	if (do_rx && do_tx && prepend_len == 0)
+ 		msg_ctl |= (SPI_FD_RW << bs->msg_type_shift);
+-	else if (t->rx_buf)
++	else if (do_rx)
+ 		msg_ctl |= (SPI_HD_R << bs->msg_type_shift);
+-	else if (t->tx_buf)
++	else if (do_tx)
+ 		msg_ctl |= (SPI_HD_W << bs->msg_type_shift);
+ 
+ 	switch (bs->msg_ctl_width) {
+@@ -209,7 +241,7 @@ static int bcm63xx_txrx_bufs(struct spi_
+ 
+ 	/* Issue the transfer */
+ 	cmd = SPI_CMD_START_IMMEDIATE;
+-	cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
++	cmd |= (prepend_len << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
+ 	cmd |= (spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
+ 	bcm_spi_writew(bs, cmd, SPI_CMD);
+ 
+@@ -223,9 +255,25 @@ static int bcm63xx_txrx_bufs(struct spi_
+ 	/* read out all data */
+ 	rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
+ 
++	if (do_rx && rx_tail != len)
++		return -EIO;
++
++	if (!rx_tail)
++		return 0;
++
++	len = 0;
++	t = first;
+ 	/* Read out all the data */
+-	if (rx_tail)
+-		memcpy_fromio(t->rx_ptr, bs->rx_io, rx_tail);
++	for (i = 0; i < num_transfers; i++) {
++		if (t->rx_buf)
++			memcpy_fromio(t->rx_buf, bs->rx_io + len, t->len);
++
++		if (t != first || prepend_len == 0)
++			len += t->len;
++
++		t = list_entry(t->transfer_list.next, struct spi_transfer,
++			       transfer_list);
++	}
+ 
+ 	return 0;
+ }
+@@ -252,46 +300,76 @@ static int bcm63xx_spi_transfer_one(stru
+ 					struct spi_message *m)
+ {
+ 	struct bcm63xx_spi *bs = spi_master_get_devdata(master);
+-	struct spi_transfer *t;
++	struct spi_transfer *t, *first = NULL;
+ 	struct spi_device *spi = m->spi;
+ 	int status = 0;
++	unsigned int n_transfers = 0, total_len = 0;
++	bool can_use_prepend = false;
+ 
++	/*
++	 * This SPI controller does not support keeping CS active after a
++	 * transfer.
++	 * Work around this by merging as many transfers we can into one big
++	 * full-duplex transfers.
++	 */
+ 	list_for_each_entry(t, &m->transfers, transfer_list) {
+ 		status = bcm63xx_spi_check_transfer(spi, t);
+ 		if (status < 0)
+ 			goto exit;
+ 
++		if (!first)
++			first = t;
++
++		n_transfers++;
++		total_len += t->len;
++
++		if (n_transfers == 2 && !first->rx_buf && !t->tx_buf &&
++		    first->len <= BCM63XX_SPI_MAX_PREPEND)
++			can_use_prepend = true;
++		else if (can_use_prepend && t->tx_buf)
++			can_use_prepend = false;
++
+ 		/* we can only transfer one fifo worth of data */
+-		if (t->len > bs->fifo_size) {
++		if ((can_use_prepend &&
++		     total_len > (bs->fifo_size + BCM63XX_SPI_MAX_PREPEND)) ||
++		    (!can_use_prepend && total_len > bs->fifo_size)) {
+ 			dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
+-				t->len, bs->fifo_size);
++				total_len, bs->fifo_size);
+ 			status = -EINVAL;
+ 			goto exit;
+ 		}
+ 
+-		/* CS will be deasserted directly after transfer */
+-		if (t->delay_usecs) {
+-			dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
++		/* all combined transfers have to have the same speed */
++		if (t->speed_hz != first->speed_hz) {
++			dev_err(&spi->dev, "unable to change speed between transfers\n");
+ 			status = -EINVAL;
+ 			goto exit;
+ 		}
+ 
+-		if (!t->cs_change &&
+-		    !list_is_last(&t->transfer_list, &m->transfers)) {
+-			dev_err(&spi->dev, "unable to keep CS asserted between transfers\n");
++		/* CS will be deasserted directly after transfer */
++		if (t->delay_usecs) {
++			dev_err(&spi->dev, "unable to keep CS asserted after transfer\n");
+ 			status = -EINVAL;
+ 			goto exit;
+ 		}
+ 
+-		/* configure adapter for a new transfer */
+-		bcm63xx_spi_setup_transfer(spi, t);
+-
+-		/* send the data */
+-		status = bcm63xx_txrx_bufs(spi, t);
+-		if (status)
+-			goto exit;
+-
+-		m->actual_length += t->len;
++		if (t->cs_change ||
++		    list_is_last(&t->transfer_list, &m->transfers)) {
++			/* configure adapter for a new transfer */
++			bcm63xx_spi_setup_transfer(spi, first);
++
++			/* send the data */
++			status = bcm63xx_txrx_bufs(spi, first, n_transfers);
++			if (status)
++				goto exit;
++
++			m->actual_length += total_len;
++
++			first = NULL;
++			n_transfers = 0;
++			total_len = 0;
++			can_use_prepend = false;
++		}
+ 	}
+ exit:
+ 	m->status = status;