/branches/gl-inet/target/linux/bcm53xx/patches-4.14/080-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 |
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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; |