[PATCH] tty: serial: cpm_uart - fix init when SMC is relocated

From: Christophe Leroy
Date: Wed May 22 2019 - 08:19:55 EST


SMC relocation can also be activated earlier by the bootloader,
so the driver's behaviour cannot rely on selected kernel config.

When the SMC is relocated, CPM_CR_INIT_TRX cannot be used.

But the only thing CPM_CR_INIT_TRX does is to clear the
rstate and tstate registers, so this can be done manually,
even when SMC is not relocated.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Fixes: 9ab921201444 ("cpm_uart: fix non-console port startup bug")
---
drivers/tty/serial/cpm_uart/cpm_uart_core.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/tty/serial/cpm_uart/cpm_uart_core.c b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
index b929c7ae3a27..7bab9a3eda92 100644
--- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c
+++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c
@@ -407,7 +407,16 @@ static int cpm_uart_startup(struct uart_port *port)
clrbits16(&pinfo->sccp->scc_sccm, UART_SCCM_RX);
}
cpm_uart_initbd(pinfo);
- cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
+ if (IS_SMC(pinfo)) {
+ out_be32(&pinfo->smcup->smc_rstate, 0);
+ out_be32(&pinfo->smcup->smc_tstate, 0);
+ out_be16(&pinfo->smcup->smc_rbptr,
+ in_be16(&pinfo->smcup->smc_rbase));
+ out_be16(&pinfo->smcup->smc_tbptr,
+ in_be16(&pinfo->smcup->smc_tbase));
+ } else {
+ cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
+ }
}
/* Install interrupt handler. */
retval = request_irq(port->irq, cpm_uart_int, 0, "cpm_uart", port);
@@ -861,16 +870,14 @@ static void cpm_uart_init_smc(struct uart_cpm_port *pinfo)
(u8 __iomem *)pinfo->tx_bd_base - DPRAM_BASE);

/*
- * In case SMC1 is being relocated...
+ * In case SMC is being relocated...
*/
-#if defined (CONFIG_I2C_SPI_SMC1_UCODE_PATCH)
out_be16(&up->smc_rbptr, in_be16(&pinfo->smcup->smc_rbase));
out_be16(&up->smc_tbptr, in_be16(&pinfo->smcup->smc_tbase));
out_be32(&up->smc_rstate, 0);
out_be32(&up->smc_tstate, 0);
out_be16(&up->smc_brkcr, 1); /* number of break chars */
out_be16(&up->smc_brkec, 0);
-#endif

/* Set up the uart parameters in the
* parameter ram.
@@ -884,8 +891,6 @@ static void cpm_uart_init_smc(struct uart_cpm_port *pinfo)
out_be16(&up->smc_brkec, 0);
out_be16(&up->smc_brkcr, 1);

- cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
-
/* Set UART mode, 8 bit, no parity, one stop.
* Enable receive and transmit.
*/
--
2.13.3