Re: [PATCH/RFC] serdev: BREAK/FRAME/PARITY/OVERRUN notification prototype
From: Geert Uytterhoeven <geert@linux-m68k.org>
Date: 2021-12-06 07:48:16
Also in:
linux-renesas-soc
Hi Magnus, On Sun, Dec 5, 2021 at 2:19 AM Magnus Damm [off-list ref] wrote:
From: Magnus Damm <redacted> A prototype patch to let serdev device drivers get notified by hardware errors such as BREAK, FRAME, PARITY and OVERRUN. With this patch, in the event of an error detected in the UART device driver the serdev_device_driver will get the newly introduced ->error() callback invoked if serdev_device_set_error_mask() has previously been used to enable the type of error. The errors are taken straight from the TTY layer and fed into the serdev_device_driver after filtering out only enabled errors. Without this patch the hardware errors never reach the serdev_device_driver. Not-Yet-Signed-off-by: Magnus Damm [off-list ref]
Thanks for your patch!
quoted hunk ↗ jump to hunk
--- 0001/drivers/tty/serdev/core.c +++ work/drivers/tty/serdev/core.c 2021-12-04 15:04:48.108809440 +0900@@ -349,6 +349,17 @@ unsigned int serdev_device_set_baudrate( } EXPORT_SYMBOL_GPL(serdev_device_set_baudrate); +void serdev_device_set_error_mask(struct serdev_device *serdev, unsigned long mask) +{ + struct serdev_controller *ctrl = serdev->ctrl; + + if (!ctrl || !ctrl->ops->set_error_mask)
Can this happen? There's only a single serdev_controller_ops structure, and it provides .set_error_mask().
+ return;
+
+ ctrl->ops->set_error_mask(ctrl, mask);
+}
+EXPORT_SYMBOL_GPL(serdev_device_set_error_mask);
+
void serdev_device_set_flow_control(struct serdev_device *serdev, bool enable)
{
struct serdev_controller *ctrl = serdev->ctrl;quoted hunk ↗ jump to hunk
@@ -27,11 +32,38 @@ static int ttyport_receive_buf(struct tt { struct serdev_controller *ctrl = port->client_data; struct serport *serport = serdev_controller_get_drvdata(ctrl); - int ret; + unsigned long errors = 0; + int i, ret;
unsigned int i;
if (!test_bit(SERPORT_ACTIVE, &serport->flags))
return 0;
+ for (i = 0; fp && i < count; i++) {
+ switch (fp[i]) {
+ case TTY_BREAK:
+ if (test_bit(SERPORT_NOTIFY_BREAK, &serport->flags))
+ set_bit(SERDEV_ERROR_BREAK, &errors);No need to use atomic ops for setting bits in errors.
quoted hunk ↗ jump to hunk
+ break; + + case TTY_FRAME: + if (test_bit(SERPORT_NOTIFY_FRAME, &serport->flags)) + set_bit(SERDEV_ERROR_FRAME, &errors); + break; + + case TTY_PARITY: + if (test_bit(SERPORT_NOTIFY_PARITY, &serport->flags)) + set_bit(SERDEV_ERROR_PARITY, &errors); + break; + + case TTY_OVERRUN: + if (test_bit(SERPORT_NOTIFY_OVERRUN, &serport->flags)) + set_bit(SERDEV_ERROR_OVERRUN, &errors); + break; + } + } + if (errors) + serdev_controller_error(ctrl, errors); + ret = serdev_controller_receive_buf(ctrl, cp, count); dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,@@ -180,6 +212,26 @@ static unsigned int ttyport_set_baudrate return ktermios.c_ospeed; } +static void ttyport_set_flags(struct serport *serport, unsigned long nflag, + unsigned long mask, unsigned long eflag) +{ + if (test_bit(eflag, &mask))
No need to use atomic ops for testing bits in mask.
quoted hunk ↗ jump to hunk
+ set_bit(nflag, &serport->flags); + else + clear_bit(nflag, &serport->flags); +} + +static void ttyport_set_error_mask(struct serdev_controller *ctrl, + unsigned long m) +{ + struct serport *sp = serdev_controller_get_drvdata(ctrl); + + ttyport_set_flags(sp, SERPORT_NOTIFY_BREAK, m, SERDEV_ERROR_BREAK); + ttyport_set_flags(sp, SERPORT_NOTIFY_FRAME, m, SERDEV_ERROR_FRAME); + ttyport_set_flags(sp, SERPORT_NOTIFY_PARITY, m, SERDEV_ERROR_PARITY); + ttyport_set_flags(sp, SERPORT_NOTIFY_OVERRUN, m, SERDEV_ERROR_OVERRUN); +} + static void ttyport_set_flow_control(struct serdev_controller *ctrl, bool enable) { struct serport *serport = serdev_controller_get_drvdata(ctrl);@@ -253,6 +305,7 @@ static const struct serdev_controller_op .write_room = ttyport_write_room, .open = ttyport_open, .close = ttyport_close, + .set_error_mask = ttyport_set_error_mask, .set_flow_control = ttyport_set_flow_control, .set_parity = ttyport_set_parity, .set_baudrate = ttyport_set_baudrate, --- 0001/include/linux/serdev.h +++ work/include/linux/serdev.h 2021-12-04 15:06:26.852815658 +0900@@ -19,12 +19,15 @@ struct serdev_device; /** * struct serdev_device_ops - Callback operations for a serdev device + * @error: Function called with errors received from device; + * may sleep. * @receive_buf: Function called with data received from device; * returns number of bytes accepted; may sleep. * @write_wakeup: Function called when ready to transmit more data; must * not sleep. */ struct serdev_device_ops { + void (*error)(struct serdev_device *, unsigned long); int (*receive_buf)(struct serdev_device *, const unsigned char *, size_t); void (*write_wakeup)(struct serdev_device *); };@@ -76,6 +79,11 @@ enum serdev_parity { SERDEV_PARITY_ODD, }; +#define SERDEV_ERROR_BREAK 0 +#define SERDEV_ERROR_FRAME 1 +#define SERDEV_ERROR_PARITY 2 +#define SERDEV_ERROR_OVERRUN 3 + /* * serdev controller structures */@@ -85,6 +93,7 @@ struct serdev_controller_ops { int (*write_room)(struct serdev_controller *); int (*open)(struct serdev_controller *); void (*close)(struct serdev_controller *); + void (*set_error_mask)(struct serdev_controller *, unsigned long); void (*set_flow_control)(struct serdev_controller *, bool); int (*set_parity)(struct serdev_controller *, enum serdev_parity); unsigned int (*set_baudrate)(struct serdev_controller *, unsigned int);
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds