From 8836384c754295b1bbbb2910664c0d07de0dbde4 Mon Sep 17 00:00:00 2001 From: Sagar Shrikant Kadam Date: Tue, 9 Jul 2019 05:23:44 -0700 Subject: [PATCH] riscv : serial: use rx watermark to indicate rx data is present In y-modem transfer mode, tstc/getc fail to check if there is any data available / received in RX FIFO, and so y-modem transfer never succeeds. Using receive watermark bit within ip register fixes the issue. This patch is based on commit c7392b7bc4e1 ("Use the RX watermark interrupt pending bit for TSTC") available at[1] [1] https://github.com/sifive/HiFive_U-Boot/tree/regression Signed-off-by: Sagar Shrikant Kadam Reviewed-by: Anup Patel Tested-by: Anup Patel Reviewed-by: Padmarao Begari Tested-by: Padmarao Begari --- drivers/serial/serial_sifive.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/serial/serial_sifive.c b/drivers/serial/serial_sifive.c index fdfef69aaa..c142ccdf3d 100644 --- a/drivers/serial/serial_sifive.c +++ b/drivers/serial/serial_sifive.c @@ -22,6 +22,9 @@ DECLARE_GLOBAL_DATA_PTR; #define UART_TXCTRL_TXEN 0x1 #define UART_RXCTRL_RXEN 0x1 +/* IP register */ +#define UART_IP_RXWM 0x2 + struct uart_sifive { u32 txfifo; u32 rxfifo; @@ -34,7 +37,6 @@ struct uart_sifive { struct sifive_uart_platdata { unsigned long clock; - int saved_input_char; struct uart_sifive *regs; }; @@ -94,7 +96,7 @@ static int _sifive_serial_getc(struct uart_sifive *regs) return -EAGAIN; ch &= UART_RXFIFO_DATA; - return (!ch) ? -EAGAIN : ch; + return ch; } static int sifive_serial_setbrg(struct udevice *dev, int baudrate) @@ -133,7 +135,6 @@ static int sifive_serial_probe(struct udevice *dev) if (gd->flags & GD_FLG_RELOC) return 0; - platdata->saved_input_char = 0; _sifive_serial_init(platdata->regs); return 0; @@ -145,12 +146,6 @@ static int sifive_serial_getc(struct udevice *dev) struct sifive_uart_platdata *platdata = dev_get_platdata(dev); struct uart_sifive *regs = platdata->regs; - if (platdata->saved_input_char > 0) { - c = platdata->saved_input_char; - platdata->saved_input_char = 0; - return c; - } - while ((c = _sifive_serial_getc(regs)) == -EAGAIN) ; return c; @@ -171,14 +166,10 @@ static int sifive_serial_pending(struct udevice *dev, bool input) struct sifive_uart_platdata *platdata = dev_get_platdata(dev); struct uart_sifive *regs = platdata->regs; - if (input) { - if (platdata->saved_input_char > 0) - return 1; - platdata->saved_input_char = _sifive_serial_getc(regs); - return (platdata->saved_input_char > 0) ? 1 : 0; - } else { + if (input) + return (readl(®s->ip) & UART_IP_RXWM); + else return !!(readl(®s->txfifo) & UART_TXFIFO_FULL); - } } static int sifive_serial_ofdata_to_platdata(struct udevice *dev)