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| author | Woody Lin <woodylin@google.com> | 2022-03-02 19:49:23 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-03-03 15:08:58 +0100 |
| commit | 3631e48df0dbfcce3b08f0ccafcaa587657379cd (patch) | |
| tree | 6a34ae9aa06b6180dbab779e214d254b8edc8d7f /drivers/tty/serial/samsung_tty.c | |
| parent | 3f8bab174cb26aa5a8053c4457cc733881e3ad88 (diff) | |
| download | linux-stable-3631e48df0dbfcce3b08f0ccafcaa587657379cd.tar.gz linux-stable-3631e48df0dbfcce3b08f0ccafcaa587657379cd.tar.bz2 linux-stable-3631e48df0dbfcce3b08f0ccafcaa587657379cd.zip | |
serial: samsung: Add samsung_early_read to support early kgdboc
The 'kgdboc_earlycon_init' looks for boot console that has both .read
and .write callbacks. Adds 'samsung_early_read' to samsung_tty.c's early
console to support kgdboc.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Woody Lin <woodylin@google.com>
Link: https://lore.kernel.org/r/20220302114923.144523-1-woodylin@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/samsung_tty.c')
| -rw-r--r-- | drivers/tty/serial/samsung_tty.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c index 2bde7bde7116..95018a847023 100644 --- a/drivers/tty/serial/samsung_tty.c +++ b/drivers/tty/serial/samsung_tty.c @@ -2949,6 +2949,7 @@ static void wr_reg_barrier(struct uart_port *port, u32 reg, u32 val) struct samsung_early_console_data { u32 txfull_mask; + u32 rxfifo_mask; }; static void samsung_early_busyuart(struct uart_port *port) @@ -2983,6 +2984,26 @@ static void samsung_early_write(struct console *con, const char *s, uart_console_write(&dev->port, s, n, samsung_early_putc); } +static int samsung_early_read(struct console *con, char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + const struct samsung_early_console_data *data = dev->port.private_data; + int ch, ufstat, num_read = 0; + + while (num_read < n) { + ufstat = rd_regl(&dev->port, S3C2410_UFSTAT); + if (!(ufstat & data->rxfifo_mask)) + break; + ch = rd_reg(&dev->port, S3C2410_URXH); + if (ch == NO_POLL_CHAR) + break; + + s[num_read++] = ch; + } + + return num_read; +} + static int __init samsung_early_console_setup(struct earlycon_device *device, const char *opt) { @@ -2990,12 +3011,14 @@ static int __init samsung_early_console_setup(struct earlycon_device *device, return -ENODEV; device->con->write = samsung_early_write; + device->con->read = samsung_early_read; return 0; } /* S3C2410 */ static struct samsung_early_console_data s3c2410_early_console_data = { .txfull_mask = S3C2410_UFSTAT_TXFULL, + .rxfifo_mask = S3C2410_UFSTAT_RXFULL | S3C2410_UFSTAT_RXMASK, }; static int __init s3c2410_early_console_setup(struct earlycon_device *device, @@ -3011,6 +3034,7 @@ OF_EARLYCON_DECLARE(s3c2410, "samsung,s3c2410-uart", /* S3C2412, S3C2440, S3C64xx */ static struct samsung_early_console_data s3c2440_early_console_data = { .txfull_mask = S3C2440_UFSTAT_TXFULL, + .rxfifo_mask = S3C2440_UFSTAT_RXFULL | S3C2440_UFSTAT_RXMASK, }; static int __init s3c2440_early_console_setup(struct earlycon_device *device, @@ -3030,6 +3054,7 @@ OF_EARLYCON_DECLARE(s3c6400, "samsung,s3c6400-uart", /* S5PV210, Exynos */ static struct samsung_early_console_data s5pv210_early_console_data = { .txfull_mask = S5PV210_UFSTAT_TXFULL, + .rxfifo_mask = S5PV210_UFSTAT_RXFULL | S5PV210_UFSTAT_RXMASK, }; static int __init s5pv210_early_console_setup(struct earlycon_device *device, |