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