aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm63xx/patches-3.8/002-spi-bcm63xx-fix-multi-transfer-messages.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/brcm63xx/patches-3.8/002-spi-bcm63xx-fix-multi-transfer-messages.patch')
-rw-r--r--target/linux/brcm63xx/patches-3.8/002-spi-bcm63xx-fix-multi-transfer-messages.patch240
1 files changed, 0 insertions, 240 deletions
diff --git a/target/linux/brcm63xx/patches-3.8/002-spi-bcm63xx-fix-multi-transfer-messages.patch b/target/linux/brcm63xx/patches-3.8/002-spi-bcm63xx-fix-multi-transfer-messages.patch
deleted file mode 100644
index 85b8524de1..0000000000
--- a/target/linux/brcm63xx/patches-3.8/002-spi-bcm63xx-fix-multi-transfer-messages.patch
+++ /dev/null
@@ -1,240 +0,0 @@
-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;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 10:40:39 +0000