leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

serial: samsung: Add samsung_early_read to support early kgdboc

Browse Source 
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>
This commit is contained in:
Woody Lin 2022-03-02 19:49:23 +08:00 committed by Greg Kroah-Hartman
parent 3f8bab174c
commit 3631e48df0
1 changed files with 25 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
drivers/tty/serial/samsung_tty.c
View File

@ -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,