tty: serial: fsl_lpuart: add LS1028A support

The LS1028A uses little endian register access and has a different FIFO
size encoding.

Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20200306214433.23215-4-michael@walle.cc
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index f45f97cb769c57782eafa8078f26562d7ee2b296..1d4f75716e32451152ec876b06aab910c234a5c0 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -234,6 +234,7 @@ static DEFINE_IDA(fsl_lpuart_ida);
 enum lpuart_type {
        VF610_LPUART,
        LS1021A_LPUART,
+       LS1028A_LPUART,
        IMX7ULP_LPUART,
        IMX8QXP_LPUART,
 };
@@ -278,11 +279,16 @@ static const struct lpuart_soc_data vf_data = {
        .iotype = UPIO_MEM,
 };
 
-static const struct lpuart_soc_data ls_data = {
+static const struct lpuart_soc_data ls1021a_data = {
        .devtype = LS1021A_LPUART,
        .iotype = UPIO_MEM32BE,
 };
 
+static const struct lpuart_soc_data ls1028a_data = {
+       .devtype = LS1028A_LPUART,
+       .iotype = UPIO_MEM32,
+};
+
 static struct lpuart_soc_data imx7ulp_data = {
        .devtype = IMX7ULP_LPUART,
        .iotype = UPIO_MEM32,
@@ -297,7 +303,8 @@ static struct lpuart_soc_data imx8qxp_data = {
 
 static const struct of_device_id lpuart_dt_ids[] = {
        { .compatible = "fsl,vf610-lpuart",     .data = &vf_data, },
-       { .compatible = "fsl,ls1021a-lpuart",   .data = &ls_data, },
+       { .compatible = "fsl,ls1021a-lpuart",   .data = &ls1021a_data, },
+       { .compatible = "fsl,ls1028a-lpuart",   .data = &ls1028a_data, },
        { .compatible = "fsl,imx7ulp-lpuart",   .data = &imx7ulp_data, },
        { .compatible = "fsl,imx8qxp-lpuart",   .data = &imx8qxp_data, },
        { /* sentinel */ }
@@ -307,6 +314,11 @@ MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
 /* Forward declare this for the dma callbacks*/
 static void lpuart_dma_tx_complete(void *arg);
 
+static inline bool is_ls1028a_lpuart(struct lpuart_port *sport)
+{
+       return sport->devtype == LS1028A_LPUART;
+}
+
 static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport)
 {
        return sport->devtype == IMX8QXP_LPUART;
@@ -1626,6 +1638,17 @@ static int lpuart32_startup(struct uart_port *port)
        sport->rxfifo_size = UARTFIFO_DEPTH((temp >> UARTFIFO_RXSIZE_OFF) &
                                            UARTFIFO_FIFOSIZE_MASK);
 
+       /*
+        * The LS1028A has a fixed length of 16 words. Although it supports the
+        * RX/TXSIZE fields their encoding is different. Eg the reference manual
+        * states 0b101 is 16 words.
+        */
+       if (is_ls1028a_lpuart(sport)) {
+               sport->rxfifo_size = 16;
+               sport->txfifo_size = 16;
+               sport->port.fifosize = sport->txfifo_size;
+       }
+
        spin_lock_irqsave(&sport->port.lock, flags);
 
        lpuart32_setup_watermark_enable(sport);