summaryrefslogtreecommitdiff
path: root/target/linux/brcm63xx/patches-3.8/001-spi-bcm63xx-reject-transfers-unable-to-transfer.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/brcm63xx/patches-3.8/001-spi-bcm63xx-reject-transfers-unable-to-transfer.patch')
-rw-r--r--target/linux/brcm63xx/patches-3.8/001-spi-bcm63xx-reject-transfers-unable-to-transfer.patch162
1 files changed, 162 insertions, 0 deletions
diff --git a/target/linux/brcm63xx/patches-3.8/001-spi-bcm63xx-reject-transfers-unable-to-transfer.patch b/target/linux/brcm63xx/patches-3.8/001-spi-bcm63xx-reject-transfers-unable-to-transfer.patch
new file mode 100644
index 0000000..8726b19
--- /dev/null
+++ b/target/linux/brcm63xx/patches-3.8/001-spi-bcm63xx-reject-transfers-unable-to-transfer.patch
@@ -0,0 +1,162 @@
+From 243970ea035623f70431a80ece802f572cd446be Mon Sep 17 00:00:00 2001
+From: Jonas Gorski <jogo@openwrt.org>
+Date: Sun, 9 Dec 2012 00:10:00 +0100
+Subject: [PATCH V2 1/2] spi/bcm63xx: reject transfers unable to transfer
+
+The hardware does not support keeping CS asserted after sending one
+FIFO buffer worth of data, so reject transfers requiring CS being kept
+asserted, either between transers or for a certain time after it,
+or exceeding the FIFO size.
+
+Signed-off-by: Jonas Gorski <jogo@openwrt.org>
+---
+ drivers/spi/spi-bcm63xx.c | 91 +++++++++++++++++++++------------------------
+ 1 file changed, 42 insertions(+), 49 deletions(-)
+
+--- a/drivers/spi/spi-bcm63xx.c
++++ b/drivers/spi/spi-bcm63xx.c
+@@ -49,16 +49,10 @@ struct bcm63xx_spi {
+ unsigned int msg_type_shift;
+ unsigned int msg_ctl_width;
+
+- /* Data buffers */
+- const unsigned char *tx_ptr;
+- unsigned char *rx_ptr;
+-
+ /* data iomem */
+ u8 __iomem *tx_io;
+ const u8 __iomem *rx_io;
+
+- int remaining_bytes;
+-
+ struct clk *clk;
+ struct platform_device *pdev;
+ };
+@@ -175,24 +169,13 @@ static int bcm63xx_spi_setup(struct spi_
+ return 0;
+ }
+
+-/* Fill the TX FIFO with as many bytes as possible */
+-static void bcm63xx_spi_fill_tx_fifo(struct bcm63xx_spi *bs)
+-{
+- u8 size;
+-
+- /* Fill the Tx FIFO with as many bytes as possible */
+- size = bs->remaining_bytes < bs->fifo_size ? bs->remaining_bytes :
+- bs->fifo_size;
+- memcpy_toio(bs->tx_io, bs->tx_ptr, size);
+- bs->remaining_bytes -= size;
+-}
+-
+-static unsigned int bcm63xx_txrx_bufs(struct spi_device *spi,
+- struct spi_transfer *t)
++static 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;
++ u8 rx_tail;
++ unsigned int timeout = 0;
+
+ /* Disable the CMD_DONE interrupt */
+ bcm_spi_writeb(bs, 0, SPI_INT_MASK);
+@@ -200,14 +183,8 @@ static unsigned int bcm63xx_txrx_bufs(st
+ 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;
+-
+- if (t->tx_buf) {
+- bs->remaining_bytes = t->len;
+- bcm63xx_spi_fill_tx_fifo(bs);
+- }
++ if (t->tx_buf)
++ memcpy_toio(bs->tx_io, t->tx_buf, t->len);
+
+ init_completion(&bs->done);
+
+@@ -239,7 +216,18 @@ static unsigned int bcm63xx_txrx_bufs(st
+ /* Enable the CMD_DONE interrupt */
+ bcm_spi_writeb(bs, SPI_INTR_CMD_DONE, SPI_INT_MASK);
+
+- return t->len - bs->remaining_bytes;
++ timeout = wait_for_completion_timeout(&bs->done, HZ);
++ if (!timeout)
++ return -ETIMEDOUT;
++
++ /* read out all data */
++ rx_tail = bcm_spi_readb(bs, SPI_RX_TAIL);
++
++ /* Read out all the data */
++ if (rx_tail)
++ memcpy_fromio(t->rx_ptr, bs->rx_io, rx_tail);
++
++ return 0;
+ }
+
+ static int bcm63xx_spi_prepare_transfer(struct spi_master *master)
+@@ -267,36 +255,41 @@ static int bcm63xx_spi_transfer_one(stru
+ 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) {
+- unsigned int len = t->len;
+- u8 rx_tail;
+-
+ status = bcm63xx_spi_check_transfer(spi, t);
+ if (status < 0)
+ goto exit;
+
++ /* we can only transfer one fifo worth of data */
++ if (t->len > bs->fifo_size) {
++ dev_err(&spi->dev, "unable to do transfers larger than FIFO size (%i > %i)\n",
++ t->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");
++ 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");
++ status = -EINVAL;
++ goto exit;
++ }
++
+ /* 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);
+- }
++ /* send the data */
++ status = bcm63xx_txrx_bufs(spi, t);
++ if (status)
++ goto exit;
+
+ m->actual_length += t->len;
+ }