Commit 00611047 authored by Mugunthan V N's avatar Mugunthan V N Committed by Mark Brown

drivers: spi: ti-qspi: wait for busy bit clear before data write/read

Data corruption is seen while reading/writing large data from/to qspi
device because the data register is over written or read before data
is ready which is denoted by busy bit in status register. SO adding
a busy bit check before writing/reading data to/from qspi device.
Signed-off-by: default avatarMugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 66886337
...@@ -101,6 +101,7 @@ struct ti_qspi { ...@@ -101,6 +101,7 @@ struct ti_qspi {
#define QSPI_FLEN(n) ((n - 1) << 0) #define QSPI_FLEN(n) ((n - 1) << 0)
/* STATUS REGISTER */ /* STATUS REGISTER */
#define BUSY 0x01
#define WC 0x02 #define WC 0x02
/* INTERRUPT REGISTER */ /* INTERRUPT REGISTER */
...@@ -199,6 +200,21 @@ static void ti_qspi_restore_ctx(struct ti_qspi *qspi) ...@@ -199,6 +200,21 @@ static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG); ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
} }
static inline u32 qspi_is_busy(struct ti_qspi *qspi)
{
u32 stat;
unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
while ((stat & BUSY) && time_after(timeout, jiffies)) {
cpu_relax();
stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
}
WARN(stat & BUSY, "qspi busy\n");
return stat & BUSY;
}
static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
{ {
int wlen, count; int wlen, count;
...@@ -211,6 +227,9 @@ static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t) ...@@ -211,6 +227,9 @@ static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
wlen = t->bits_per_word >> 3; /* in bytes */ wlen = t->bits_per_word >> 3; /* in bytes */
while (count) { while (count) {
if (qspi_is_busy(qspi))
return -EBUSY;
switch (wlen) { switch (wlen) {
case 1: case 1:
dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n", dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
...@@ -266,6 +285,9 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t) ...@@ -266,6 +285,9 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
while (count) { while (count) {
dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc); dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
if (qspi_is_busy(qspi))
return -EBUSY;
ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG); ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
if (!wait_for_completion_timeout(&qspi->transfer_complete, if (!wait_for_completion_timeout(&qspi->transfer_complete,
QSPI_COMPLETION_TIMEOUT)) { QSPI_COMPLETION_TIMEOUT)) {
......
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