diff options
Diffstat (limited to 'target/linux/bcm53xx/patches-4.4/084-0003-spi-bcm53xx-simplify-reading-SPI-data.patch')
| -rw-r--r-- | target/linux/bcm53xx/patches-4.4/084-0003-spi-bcm53xx-simplify-reading-SPI-data.patch | 107 |
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; |