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-rw-r--r--target/linux/bcm53xx/patches-4.4/084-0003-spi-bcm53xx-simplify-reading-SPI-data.patch107
1 files changed, 107 insertions, 0 deletions
diff --git a/target/linux/bcm53xx/patches-4.4/084-0003-spi-bcm53xx-simplify-reading-SPI-data.patch b/target/linux/bcm53xx/patches-4.4/084-0003-spi-bcm53xx-simplify-reading-SPI-data.patch
new file mode 100644
index 0000000000..ee377c491f
--- /dev/null
+++ b/target/linux/bcm53xx/patches-4.4/084-0003-spi-bcm53xx-simplify-reading-SPI-data.patch
@@ -0,0 +1,107 @@
+From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
+Date: Fri, 29 Dec 2017 14:44:09 +0100
+Subject: [PATCH] spi: bcm53xx: simplify reading SPI data
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This commit makes transfer function use spi_transfer_is_last to
+determine if currently processed transfer is the last one. Thanks to
+that we finally set hardware registers properly and it makes controller
+behave the way it's expected to.
+
+This allows simplifying read function which can now simply start reading
+from the slot 0 instead of the last saved offset. It has been
+successfully tested using spi_write_then_read.
+
+Moreover this change fixes handling messages with two writing transfers.
+It's important for SPI flash devices as their drivers commonly use one
+transfer for a command and another one for data.
+
+Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
+---
+ drivers/spi/spi-bcm53xx.c | 26 ++++++++++----------------
+ 1 file changed, 10 insertions(+), 16 deletions(-)
+
+--- a/drivers/spi/spi-bcm53xx.c
++++ b/drivers/spi/spi-bcm53xx.c
+@@ -27,8 +27,6 @@ struct bcm53xxspi {
+ struct bcma_device *core;
+ struct spi_master *master;
+ void __iomem *mmio_base;
+-
+- size_t read_offset;
+ bool bspi; /* Boot SPI mode with memory mapping */
+ };
+
+@@ -172,8 +170,6 @@ static void bcm53xxspi_buf_write(struct
+
+ if (!cont)
+ bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);
+-
+- b53spi->read_offset = len;
+ }
+
+ static void bcm53xxspi_buf_read(struct bcm53xxspi *b53spi, u8 *r_buf,
+@@ -182,10 +178,10 @@ static void bcm53xxspi_buf_read(struct b
+ u32 tmp;
+ int i;
+
+- for (i = 0; i < b53spi->read_offset + len; i++) {
++ for (i = 0; i < len; i++) {
+ tmp = B53SPI_CDRAM_CONT | B53SPI_CDRAM_PCS_DISABLE_ALL |
+ B53SPI_CDRAM_PCS_DSCK;
+- if (!cont && i == b53spi->read_offset + len - 1)
++ if (!cont && i == len - 1)
+ tmp &= ~B53SPI_CDRAM_CONT;
+ tmp &= ~0x1;
+ /* Command Register File */
+@@ -194,8 +190,7 @@ static void bcm53xxspi_buf_read(struct b
+
+ /* Set queue pointers */
+ bcm53xxspi_write(b53spi, B53SPI_MSPI_NEWQP, 0);
+- bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP,
+- b53spi->read_offset + len - 1);
++ bcm53xxspi_write(b53spi, B53SPI_MSPI_ENDQP, len - 1);
+
+ if (cont)
+ bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 1);
+@@ -214,13 +209,11 @@ static void bcm53xxspi_buf_read(struct b
+ bcm53xxspi_write(b53spi, B53SPI_MSPI_WRITE_LOCK, 0);
+
+ for (i = 0; i < len; ++i) {
+- int offset = b53spi->read_offset + i;
++ u16 reg = B53SPI_MSPI_RXRAM + 4 * (1 + i * 2);
+
+ /* Data stored in the transmit register file LSB */
+- r_buf[i] = (u8)bcm53xxspi_read(b53spi, B53SPI_MSPI_RXRAM + 4 * (1 + offset * 2));
++ r_buf[i] = (u8)bcm53xxspi_read(b53spi, reg);
+ }
+-
+- b53spi->read_offset = 0;
+ }
+
+ static int bcm53xxspi_transfer_one(struct spi_master *master,
+@@ -238,7 +231,8 @@ static int bcm53xxspi_transfer_one(struc
+ left = t->len;
+ while (left) {
+ size_t to_write = min_t(size_t, 16, left);
+- bool cont = left - to_write > 0;
++ bool cont = !spi_transfer_is_last(master, t) ||
++ left - to_write > 0;
+
+ bcm53xxspi_buf_write(b53spi, buf, to_write, cont);
+ left -= to_write;
+@@ -250,9 +244,9 @@ static int bcm53xxspi_transfer_one(struc
+ buf = (u8 *)t->rx_buf;
+ left = t->len;
+ while (left) {
+- size_t to_read = min_t(size_t, 16 - b53spi->read_offset,
+- left);
+- bool cont = left - to_read > 0;
++ size_t to_read = min_t(size_t, 16, left);
++ bool cont = !spi_transfer_is_last(master, t) ||
++ left - to_read > 0;
+
+ bcm53xxspi_buf_read(b53spi, buf, to_read, cont);
+ left -= to_read;