diff mbox series

[v4,13/21] spi: dw: De-assert chip-select on reset

Message ID 20201007235511.4935-14-Sergey.Semin@baikalelectronics.ru
State Accepted
Commit fbddc989a5c441099978aad320ada0d5327309f4
Headers show
Series spi: dw: Add full Baikal-T1 SPI Controllers support | expand

Commit Message

Serge Semin Oct. 7, 2020, 11:55 p.m. UTC 
SPI memory operations implementation will require to have the CS register
cleared before executing the operation in order not to have the
transmission automatically started prior the Tx FIFO is pre-initialized.
Let's clear the register then on explicit controller reset to fulfil the
requirements in case of an error or having the CS left set by a bootloader
or another software.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
---
 drivers/spi/spi-dw.h | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index cfc9f63acde4..eb1d46983319 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -237,15 +237,16 @@  static inline void spi_umask_intr(struct dw_spi *dws, u32 mask)
 }
 
 /*
- * This disables the SPI controller, interrupts, clears the interrupts status,
- * and re-enable the controller back. Transmit and receive FIFO buffers are
- * cleared when the device is disabled.
+ * This disables the SPI controller, interrupts, clears the interrupts status
+ * and CS, then re-enables the controller back. Transmit and receive FIFO
+ * buffers are cleared when the device is disabled.
  */
 static inline void spi_reset_chip(struct dw_spi *dws)
 {
 	spi_enable_chip(dws, 0);
 	spi_mask_intr(dws, 0xff);
 	dw_readl(dws, DW_SPI_ICR);
+	dw_writel(dws, DW_SPI_SER, 0);
 	spi_enable_chip(dws, 1);
 }