Messages in this thread | | | Subject | Re: [PATCH v2] gnss: get serial speed from subdrivers | From | Robin Murphy <> | Date | Thu, 16 May 2019 19:02:05 +0100 |
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On 16/05/2019 17:37, Loys Ollivier wrote: > The default serial speed was hardcoded in the code. > Rename current-speed to default-speed. > Add a function parameter that lets the subdrivers specify their > default speed. > If not specified fallback to the device-tree default-speed. > > Signed-off-by: Loys Ollivier <lollivier@baylibre.com> > --- > Hello, > > This patch moves the currently hardcoded, default serial speed > to the subdrivers. > If the default speed is not specified by the subdriver then it is read > from the device tree. > > Changes since v1[0] > - Use u32 data types instead of uint > > [0]: https://lore.kernel.org/lkml/1557322788-10403-1-git-send-email-lollivier@baylibre.com/ > > Cheers, > Loys > > drivers/gnss/mtk.c | 7 ++++++- > drivers/gnss/serial.c | 21 +++++++++++++-------- > drivers/gnss/serial.h | 3 ++- > drivers/gnss/ubx.c | 3 ++- > 4 files changed, 23 insertions(+), 11 deletions(-) > > diff --git a/drivers/gnss/mtk.c b/drivers/gnss/mtk.c > index d1fc55560daf..1d35bcb52072 100644 > --- a/drivers/gnss/mtk.c > +++ b/drivers/gnss/mtk.c > @@ -16,6 +16,10 @@ > > #include "serial.h" > > +static uint serial_speed = 9600; /* Serial speed (baud rate) */ > +module_param(serial_speed, uint, 0644); > +MODULE_PARM_DESC(serial_speed, "Serial baud rate (bit/s), (default = 9600)"); > + > struct mtk_data { > struct regulator *vbackup; > struct regulator *vcc; > @@ -69,7 +73,8 @@ static int mtk_probe(struct serdev_device *serdev) > struct mtk_data *data; > int ret; > > - gserial = gnss_serial_allocate(serdev, sizeof(*data)); > + gserial = gnss_serial_allocate(serdev, sizeof(*data), > + (u32)serial_speed); > if (IS_ERR(gserial)) { > ret = PTR_ERR(gserial); > return ret; > diff --git a/drivers/gnss/serial.c b/drivers/gnss/serial.c > index def64b36d994..3be799702291 100644 > --- a/drivers/gnss/serial.c > +++ b/drivers/gnss/serial.c > @@ -103,17 +103,13 @@ static int gnss_serial_set_power(struct gnss_serial *gserial, > return gserial->ops->set_power(gserial, state); > } > > -/* > - * FIXME: need to provide subdriver defaults or separate dt parsing from > - * allocation. > - */ > static int gnss_serial_parse_dt(struct serdev_device *serdev) > { > struct gnss_serial *gserial = serdev_device_get_drvdata(serdev); > struct device_node *node = serdev->dev.of_node; > - u32 speed = 4800; > + u32 speed; > > - of_property_read_u32(node, "current-speed", &speed); > + of_property_read_u32(node, "default-speed", &speed); > > gserial->speed = speed;
Hmm, maybe it's a bit too convoluted for the compiler to warn about, but if a "default-speed" property is not present, gserial->speed will now be assigned an uninitialised value. I don't know what the intent is neither the driver nor the DT provides a value, but you'll either need to bring back the fallback initialisation above or propagate errors from of_property_read_u32().
Robin.
> > @@ -121,7 +117,8 @@ static int gnss_serial_parse_dt(struct serdev_device *serdev) > } > > struct gnss_serial *gnss_serial_allocate(struct serdev_device *serdev, > - size_t data_size) > + size_t data_size, > + u32 serial_speed) > { > struct gnss_serial *gserial; > struct gnss_device *gdev; > @@ -146,10 +143,18 @@ struct gnss_serial *gnss_serial_allocate(struct serdev_device *serdev, > serdev_device_set_drvdata(serdev, gserial); > serdev_device_set_client_ops(serdev, &gnss_serial_serdev_ops); > > - ret = gnss_serial_parse_dt(serdev); > + /* Serial speed provided by subdriver takes precedence over dt*/ > + if (!serial_speed) > + ret = gnss_serial_parse_dt(serdev); > + else > + gserial->speed = serial_speed; > + > if (ret) > goto err_put_device; > > + if (!gserial->speed) > + return -EINVAL; > + > return gserial; > > err_put_device: > diff --git a/drivers/gnss/serial.h b/drivers/gnss/serial.h > index 980ffdc86c2a..17df61e399e6 100644 > --- a/drivers/gnss/serial.h > +++ b/drivers/gnss/serial.h > @@ -33,7 +33,8 @@ struct gnss_serial_ops { > extern const struct dev_pm_ops gnss_serial_pm_ops; > > struct gnss_serial *gnss_serial_allocate(struct serdev_device *gserial, > - size_t data_size); > + size_t data_size, > + u32 serial_speed); > void gnss_serial_free(struct gnss_serial *gserial); > > int gnss_serial_register(struct gnss_serial *gserial); > diff --git a/drivers/gnss/ubx.c b/drivers/gnss/ubx.c > index 7b05bc40532e..52ae6e4987e0 100644 > --- a/drivers/gnss/ubx.c > +++ b/drivers/gnss/ubx.c > @@ -68,8 +68,9 @@ static int ubx_probe(struct serdev_device *serdev) > struct gnss_serial *gserial; > struct ubx_data *data; > int ret; > + u32 speed = 4800; > > - gserial = gnss_serial_allocate(serdev, sizeof(*data)); > + gserial = gnss_serial_allocate(serdev, sizeof(*data), speed); > if (IS_ERR(gserial)) { > ret = PTR_ERR(gserial); > return ret; >
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