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spi: fsl-spi: Don't use cpm_command on CPM1

PATCH Applied Christophe Leroy 2 participants 2 messages Nov 20, 2014 – Nov 21, 2014 SPI

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PATCH 1/1 spi: fsl-spi: Don't use cpm_command on CPM1

On CPM1, when the SPI parameter RAM is relocated to somewhere else than the default location, in accordance with freescale documentation (refer micropatch SPI application note EB662), init RX/TX params command shall not be used because it doesn't take into account the new location, and overwrites data that is in original location of SPI param ram at addresses SCC2 param base + (u32*)0x88 (u16*)0x90 (u32*)0x98 (u16*)0xA0, hence breaking activity on SCC2 if SCC2 is used in a mode like QMC for instance.

Therefore, the action shall be done manually as described by freescale and as was already partly done by the driver.

---
 drivers/spi/spi-fsl-cpm.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
drivers/spi/spi-fsl-cpm.c +4 -1
index 54b0637..da97988 100644
@@ -56,12 +56,15 @@ void fsl_spi_cpm_reinit_txrx(struct mpc8xxx_spi *mspi)
 		qe_issue_cmd(QE_INIT_TX_RX, mspi->subblock,
 			     QE_CR_PROTOCOL_UNSPECIFIED, 0);
 	} else {
-		cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
 		if (mspi->flags & SPI_CPM1) {
+			out_be32(&mspi->pram->rstate, 0);
 			out_be16(&mspi->pram->rbptr,
 				 in_be16(&mspi->pram->rbase));
+			out_be32(&mspi->pram->tstate, 0);
 			out_be16(&mspi->pram->tbptr,
 				 in_be16(&mspi->pram->tbase));
+		} else {
+			cpm_command(CPM_SPI_CMD, CPM_CR_INIT_TRX);
 		}
 	}
 }
Signature · 1 line
2.1.0
maintainer Applied
#1 lore raw
Quoted 7 lines · Christophe Leroy

On CPM1, when the SPI parameter RAM is relocated to somewhere else than the default location, in accordance with freescale documentation (refer micropatch SPI application note EB662), init RX/TX params command shall not be used because it doesn't take into account the new location, and overwrites data that is in original location of SPI param ram at addresses SCC2 param base + (u32*)0x88 (u16*)0x90 (u32*)0x98 (u16*)0xA0, hence breaking activity on SCC2 if SCC2 is used in a mode like QMC for instance.

Applied, thanks.