[PATCH v2] treewide, serdev: change receive_buf() return type to size_t

Francesco Dolcini
2024-01-22T18:06:05Z

From: Francesco Dolcini <francesco.dolcini@toradex.com>

receive_buf() is called from ttyport_receive_buf() that expects values
">= 0" from serdev_controller_receive_buf(), change its return type from
ssize_t to size_t.

The need for this clean-up was noticed while fixing a warning, see
commit 94d053942544 ("Bluetooth: btnxpuart: fix recv_buf() return value").
Changing the callback prototype to return an unsigned seems the best way
to document the API and ensure that is properly used.

GNSS drivers implementation of serdev receive_buf() callback return
directly the return value of gnss_insert_raw(). gnss_insert_raw()
returns a signed int, however this is not an issue since the value
returned is always positive, because of the kfifo_in() implementation.
gnss_insert_raw() could be changed to return also an unsigned, however
this is not implemented here as request by the GNSS maintainer Johan
Hovold.

Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/all/087be419-ec6b-47ad-851a-5e1e3ea5cfcc@kernel.org/
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> #for-iio
---
v1:
- https://lore.kernel.org/all/20231214170146.641783-1-francesco@dolcini.it/
v2:
- rebased on 6.8-rc1
- add acked-by Jonathan
- do not change gnss_insert_raw()
- do not change the code style of the gnss code
- commit message improvements, explain the reasons for doing only minimal
changes on the GNSS part
---
drivers/bluetooth/btmtkuart.c | 4 ++--
drivers/bluetooth/btnxpuart.c | 4 ++--
drivers/bluetooth/hci_serdev.c | 4 ++--
drivers/gnss/serial.c | 2 +-
drivers/gnss/sirf.c | 2 +-
drivers/greybus/gb-beagleplay.c | 6 +++---
drivers/iio/chemical/pms7003.c | 4 ++--
drivers/iio/chemical/scd30_serial.c | 4 ++--
drivers/iio/chemical/sps30_serial.c | 4 ++--
drivers/iio/imu/bno055/bno055_ser_core.c | 4 ++--
drivers/mfd/rave-sp.c | 4 ++--
drivers/net/ethernet/qualcomm/qca_uart.c | 2 +-
drivers/nfc/pn533/uart.c | 4 ++--
drivers/nfc/s3fwrn5/uart.c | 4 ++--
drivers/platform/chrome/cros_ec_uart.c | 4 ++--
drivers/platform/surface/aggregator/core.c | 4 ++--
drivers/tty/serdev/serdev-ttyport.c | 10 ++++------
include/linux/serdev.h | 8 ++++----
sound/drivers/serial-generic.c | 4 ++--
19 files changed, 40 insertions(+), 42 deletions(-)

diff --git a/drivers/bluetooth/btmtkuart.c b/drivers/bluetooth/btmtkuart.c
index 3c84fcbda01a..e6bc4a73c9fc 100644
--- a/drivers/bluetooth/btmtkuart.c
+++ b/drivers/bluetooth/btmtkuart.c
@@ -383,8 +383,8 @@ static void btmtkuart_recv(struct hci_dev *hdev, const u8 *data, size_t count)
}
}

-static ssize_t btmtkuart_receive_buf(struct serdev_device *serdev,
- const u8 *data, size_t count)
+static size_t btmtkuart_receive_buf(struct serdev_device *serdev,
+ const u8 *data, size_t count)
{
struct btmtkuart_dev *bdev = serdev_device_get_drvdata(serdev);

diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index 1d592ac413d1..056bef5b2919 100644
--- a/drivers/bluetooth/btnxpuart.c
+++ b/drivers/bluetooth/btnxpuart.c
@@ -1264,8 +1264,8 @@ static const struct h4_recv_pkt nxp_recv_pkts[] = {
{ NXP_RECV_FW_REQ_V3, .recv = nxp_recv_fw_req_v3 },
};

-static ssize_t btnxpuart_receive_buf(struct serdev_device *serdev,
- const u8 *data, size_t count)
+static size_t btnxpuart_receive_buf(struct serdev_device *serdev,
+ const u8 *data, size_t count)
{
struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);

diff --git a/drivers/bluetooth/hci_serdev.c b/drivers/bluetooth/hci_serdev.c
index 39c8b567da3c..a3c3beb2806d 100644
--- a/drivers/bluetooth/hci_serdev.c
+++ b/drivers/bluetooth/hci_serdev.c
@@ -271,8 +271,8 @@ static void hci_uart_write_wakeup(struct serdev_device *serdev)
*
* Return: number of processed bytes
*/
-static ssize_t hci_uart_receive_buf(struct serdev_device *serdev,
- const u8 *data, size_t count)
+static size_t hci_uart_receive_buf(struct serdev_device *serdev,
+ const u8 *data, size_t count)
{
struct hci_uart *hu = serdev_device_get_drvdata(serdev);

diff --git a/drivers/gnss/serial.c b/drivers/gnss/serial.c
index baa956494e79..0e43bf6294f8 100644
--- a/drivers/gnss/serial.c
+++ b/drivers/gnss/serial.c
@@ -80,7 +80,7 @@ static const struct gnss_operations gnss_serial_gnss_ops = {
.write_raw = gnss_serial_write_raw,
};

-static ssize_t gnss_serial_receive_buf(struct serdev_device *serdev,
+static size_t gnss_serial_receive_buf(struct serdev_device *serdev,
const u8 *buf, size_t count)
{
struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
diff --git a/drivers/gnss/sirf.c b/drivers/gnss/sirf.c
index 6801a8fb2040..79375d14bbb6 100644
--- a/drivers/gnss/sirf.c
+++ b/drivers/gnss/sirf.c
@@ -160,7 +160,7 @@ static const struct gnss_operations sirf_gnss_ops = {
.write_raw = sirf_write_raw,
};

-static ssize_t sirf_receive_buf(struct serdev_device *serdev,
+static size_t sirf_receive_buf(struct serdev_device *serdev,
const u8 *buf, size_t count)
{
struct sirf_data *data = serdev_device_get_drvdata(serdev);
diff --git a/drivers/greybus/gb-beagleplay.c b/drivers/greybus/gb-beagleplay.c
index c3e90025064b..33f8fad70260 100644
--- a/drivers/greybus/gb-beagleplay.c
+++ b/drivers/greybus/gb-beagleplay.c
@@ -271,7 +271,7 @@ static void hdlc_rx_frame(struct gb_beagleplay *bg)
}
}

-static ssize_t hdlc_rx(struct gb_beagleplay *bg, const u8 *data, size_t count)
+static size_t hdlc_rx(struct gb_beagleplay *bg, const u8 *data, size_t count)
{
size_t i;
u8 c;
@@ -331,8 +331,8 @@ static void hdlc_deinit(struct gb_beagleplay *bg)
flush_work(&bg->tx_work);
}

-static ssize_t gb_tty_receive(struct serdev_device *sd, const u8 *data,
- size_t count)
+static size_t gb_tty_receive(struct serdev_device *sd, const u8 *data,
+ size_t count)
{
struct gb_beagleplay *bg = serdev_device_get_drvdata(sd);

diff --git a/drivers/iio/chemical/pms7003.c b/drivers/iio/chemical/pms7003.c
index b5cf15a515d2..43025866d5b7 100644
--- a/drivers/iio/chemical/pms7003.c
+++ b/drivers/iio/chemical/pms7003.c
@@ -211,8 +211,8 @@ static bool pms7003_frame_is_okay(struct pms7003_frame *frame)
return checksum == pms7003_calc_checksum(frame);
}

-static ssize_t pms7003_receive_buf(struct serdev_device *serdev, const u8 *buf,
- size_t size)
+static size_t pms7003_receive_buf(struct serdev_device *serdev, const u8 *buf,
+ size_t size)
{
struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
struct pms7003_state *state = iio_priv(indio_dev);
diff --git a/drivers/iio/chemical/scd30_serial.c b/drivers/iio/chemical/scd30_serial.c
index a47654591e55..2adb76dbb020 100644
--- a/drivers/iio/chemical/scd30_serial.c
+++ b/drivers/iio/chemical/scd30_serial.c
@@ -174,8 +174,8 @@ static int scd30_serdev_command(struct scd30_state *state, enum scd30_cmd cmd, u
return 0;
}

-static ssize_t scd30_serdev_receive_buf(struct serdev_device *serdev,
- const u8 *buf, size_t size)
+static size_t scd30_serdev_receive_buf(struct serdev_device *serdev,
+ const u8 *buf, size_t size)
{
struct iio_dev *indio_dev = serdev_device_get_drvdata(serdev);
struct scd30_serdev_priv *priv;
diff --git a/drivers/iio/chemical/sps30_serial.c b/drivers/iio/chemical/sps30_serial.c
index 3afa89f8acc3..a6dfbe28c914 100644
--- a/drivers/iio/chemical/sps30_serial.c
+++ b/drivers/iio/chemical/sps30_serial.c
@@ -210,8 +210,8 @@ static int sps30_serial_command(struct sps30_state *state, unsigned char cmd,
return rsp_size;
}

-static ssize_t sps30_serial_receive_buf(struct serdev_device *serdev,
- const u8 *buf, size_t size)
+static size_t sps30_serial_receive_buf(struct serdev_device *serdev,
+ const u8 *buf, size_t size)
{
struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev);
struct sps30_serial_priv *priv;
diff --git a/drivers/iio/imu/bno055/bno055_ser_core.c b/drivers/iio/imu/bno055/bno055_ser_core.c
index 5677bdf4f846..694ff14a3aa2 100644
--- a/drivers/iio/imu/bno055/bno055_ser_core.c
+++ b/drivers/iio/imu/bno055/bno055_ser_core.c
@@ -378,8 +378,8 @@ static void bno055_ser_handle_rx(struct bno055_ser_priv *priv, int status)
* Also, we assume to RX one pkt per time (i.e. the HW doesn't send anything
* unless we require to AND we don't queue more than one request per time).
*/
-static ssize_t bno055_ser_receive_buf(struct serdev_device *serdev,
- const u8 *buf, size_t size)
+static size_t bno055_ser_receive_buf(struct serdev_device *serdev,
+ const u8 *buf, size_t size)
{
int status;
struct bno055_ser_priv *priv = serdev_device_get_drvdata(serdev);
diff --git a/drivers/mfd/rave-sp.c b/drivers/mfd/rave-sp.c
index 6ff84b2600c5..62a6613fb070 100644
--- a/drivers/mfd/rave-sp.c
+++ b/drivers/mfd/rave-sp.c
@@ -471,8 +471,8 @@ static void rave_sp_receive_frame(struct rave_sp *sp,
rave_sp_receive_reply(sp, data, length);
}

-static ssize_t rave_sp_receive_buf(struct serdev_device *serdev,
- const u8 *buf, size_t size)
+static size_t rave_sp_receive_buf(struct serdev_device *serdev,
+ const u8 *buf, size_t size)
{
struct device *dev = &serdev->dev;
struct rave_sp *sp = dev_get_drvdata(dev);
diff --git a/drivers/net/ethernet/qualcomm/qca_uart.c b/drivers/net/ethernet/qualcomm/qca_uart.c
index 223321897b96..20f50bde82ac 100644
--- a/drivers/net/ethernet/qualcomm/qca_uart.c
+++ b/drivers/net/ethernet/qualcomm/qca_uart.c
@@ -58,7 +58,7 @@ struct qcauart {
unsigned char *tx_buffer;
};

-static ssize_t
+static size_t
qca_tty_receive(struct serdev_device *serdev, const u8 *data, size_t count)
{
struct qcauart *qca = serdev_device_get_drvdata(serdev);
diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c
index 2eb5978bd79e..cfbbe0713317 100644
--- a/drivers/nfc/pn533/uart.c
+++ b/drivers/nfc/pn533/uart.c
@@ -203,8 +203,8 @@ static int pn532_uart_rx_is_frame(struct sk_buff *skb)
return 0;
}

-static ssize_t pn532_receive_buf(struct serdev_device *serdev,
- const u8 *data, size_t count)
+static size_t pn532_receive_buf(struct serdev_device *serdev,
+ const u8 *data, size_t count)
{
struct pn532_uart_phy *dev = serdev_device_get_drvdata(serdev);
size_t i;
diff --git a/drivers/nfc/s3fwrn5/uart.c b/drivers/nfc/s3fwrn5/uart.c
index 456d3947116c..9c09c10c2a46 100644
--- a/drivers/nfc/s3fwrn5/uart.c
+++ b/drivers/nfc/s3fwrn5/uart.c
@@ -51,8 +51,8 @@ static const struct s3fwrn5_phy_ops uart_phy_ops = {
.write = s3fwrn82_uart_write,
};

-static ssize_t s3fwrn82_uart_read(struct serdev_device *serdev,
- const u8 *data, size_t count)
+static size_t s3fwrn82_uart_read(struct serdev_device *serdev,
+ const u8 *data, size_t count)
{
struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev);
size_t i;
diff --git a/drivers/platform/chrome/cros_ec_uart.c b/drivers/platform/chrome/cros_ec_uart.c
index 68d80559fddc..8ea867c2a01a 100644
--- a/drivers/platform/chrome/cros_ec_uart.c
+++ b/drivers/platform/chrome/cros_ec_uart.c
@@ -81,8 +81,8 @@ struct cros_ec_uart {
struct response_info response;
};

-static ssize_t cros_ec_uart_rx_bytes(struct serdev_device *serdev,
- const u8 *data, size_t count)
+static size_t cros_ec_uart_rx_bytes(struct serdev_device *serdev,
+ const u8 *data, size_t count)
{
struct ec_host_response *host_response;
struct cros_ec_device *ec_dev = serdev_device_get_drvdata(serdev);
diff --git a/drivers/platform/surface/aggregator/core.c b/drivers/platform/surface/aggregator/core.c
index 9591a28bc38a..ba550eaa06fc 100644
--- a/drivers/platform/surface/aggregator/core.c
+++ b/drivers/platform/surface/aggregator/core.c
@@ -227,8 +227,8 @@ EXPORT_SYMBOL_GPL(ssam_client_bind);

/* -- Glue layer (serdev_device -> ssam_controller). ------------------------ */

-static ssize_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
- size_t n)
+static size_t ssam_receive_buf(struct serdev_device *dev, const u8 *buf,
+ size_t n)
{
struct ssam_controller *ctrl;
int ret;
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index e94e090cf0a1..3d7ae7fa5018 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -27,19 +27,17 @@ static size_t ttyport_receive_buf(struct tty_port *port, const u8 *cp,
{
struct serdev_controller *ctrl = port->client_data;
struct serport *serport = serdev_controller_get_drvdata(ctrl);
- int ret;
+ size_t ret;

if (!test_bit(SERPORT_ACTIVE, &serport->flags))
return 0;

ret = serdev_controller_receive_buf(ctrl, cp, count);

- dev_WARN_ONCE(&ctrl->dev, ret < 0 || ret > count,
- "receive_buf returns %d (count = %zu)\n",
+ dev_WARN_ONCE(&ctrl->dev, ret > count,
+ "receive_buf returns %zu (count = %zu)\n",
ret, count);
- if (ret < 0)
- return 0;
- else if (ret > count)
+ if (ret > count)
return count;

return ret;
diff --git a/include/linux/serdev.h b/include/linux/serdev.h
index 3fab88ba265e..ff78efc1f60d 100644
--- a/include/linux/serdev.h
+++ b/include/linux/serdev.h
@@ -27,7 +27,7 @@ struct serdev_device;
* not sleep.
*/
struct serdev_device_ops {
- ssize_t (*receive_buf)(struct serdev_device *, const u8 *, size_t);
+ size_t (*receive_buf)(struct serdev_device *, const u8 *, size_t);
void (*write_wakeup)(struct serdev_device *);
};

@@ -185,9 +185,9 @@ static inline void serdev_controller_write_wakeup(struct serdev_controller *ctrl
serdev->ops->write_wakeup(serdev);
}

-static inline ssize_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
- const u8 *data,
- size_t count)
+static inline size_t serdev_controller_receive_buf(struct serdev_controller *ctrl,
+ const u8 *data,
+ size_t count)
{
struct serdev_device *serdev = ctrl->serdev;

diff --git a/sound/drivers/serial-generic.c b/sound/drivers/serial-generic.c
index d6e5aafd697c..36409a56c675 100644
--- a/sound/drivers/serial-generic.c
+++ b/sound/drivers/serial-generic.c
@@ -100,8 +100,8 @@ static void snd_serial_generic_write_wakeup(struct serdev_device *serdev)
snd_serial_generic_tx_wakeup(drvdata);
}

-static ssize_t snd_serial_generic_receive_buf(struct serdev_device *serdev,
- const u8 *buf, size_t count)
+static size_t snd_serial_generic_receive_buf(struct serdev_device *serdev,
+ const u8 *buf, size_t count)
{
int ret;
struct snd_serial_generic *drvdata = serdev_device_get_drvdata(serdev);
--
2.39.2