On Thu, 2024-05-02 at 10:44 +0200, Jiri Slaby wrote: > On 02. 05. 24, 9:55, Christoph Fritz wrote: > > This commit introduces LIN-Bus support for UART devices equipped with > > LIN transceivers, utilizing the Serial Device Bus (serdev) interface. > > > > For more details on an adapter, visit: https://hexdev.de/hexlin#tty > ... > > --- /dev/null > > +++ b/drivers/net/can/lin-serdev.c > > @@ -0,0 +1,514 @@ > > +// SPDX-License-Identifier: GPL-2.0+ > > +/* Copyright (C) 2024 hexDEV GmbH - https://hexdev.de */ > > + > > +#include <linux/module.h> > > +#include <linux/wait.h> > > +#include <linux/init.h> > > +#include <linux/errno.h> > > +#include <linux/string.h> > > +#include <linux/kernel.h> > > What do you need kernel.h for? You should explicitly require what you > need (you apparently do), so kernel.h should not be needed. OK > > > +#include <net/lin.h> > > +#include <linux/of.h> > > +#include <linux/serdev.h> > > +#include <linux/slab.h> > > +#include <linux/kfifo.h> > > +#include <linux/workqueue.h> > > +#include <linux/tty.h> > > Might be eaier to maintain if you sort them. OK, hid driver gets also sorted > > > +#define LINSER_SAMPLES_PER_CHAR 10 > > +#define LINSER_TX_BUFFER_SIZE 11 > > +#define LINSER_RX_FIFO_SIZE 256 > > +#define LINSER_PARSE_BUFFER 24 > > + > > +struct linser_rx { > > + u8 data; > > + u8 flag; > > +}; > > + > > +enum linser_rx_status { > > + NEED_MORE = -1, > > + MODE_OK = 0, > > + NEED_FORCE, > > +}; > > + > > +struct linser_priv { > > + struct lin_device *lin_dev; > > + struct serdev_device *serdev; > > + DECLARE_KFIFO_PTR(rx_fifo, struct linser_rx); > > + struct delayed_work rx_work; > > + ulong break_usleep_min; > > + ulong break_usleep_max; > > + ulong post_break_usleep_min; > > + ulong post_break_usleep_max; > > + ulong force_timeout_jfs; > > The same as for uint :) OK > > > + struct lin_responder_answer respond_answ[LIN_NUM_IDS]; > > + struct mutex resp_lock; /* protects respond_answ */ > > + bool is_stopped; > > +}; > ... > > +static void linser_derive_timings(struct linser_priv *priv, u16 bitrate) > > +{ > > + unsigned long break_baud = (bitrate * 2) / 3; > > + unsigned long timeout_us; > > + > > Are those 1000000UL USEC_PER_SEC? yes > > > + priv->break_usleep_min = (1000000UL * LINSER_SAMPLES_PER_CHAR) / > > + break_baud; > > + priv->break_usleep_max = priv->break_usleep_min + 50; > > + priv->post_break_usleep_min = (1000000UL * 1 /* 1 bit */) / break_baud; > > + priv->post_break_usleep_max = priv->post_break_usleep_min + 30; > > + > > + timeout_us = DIV_ROUND_CLOSEST(1000000UL * 256 /* bit */, bitrate); > > + priv->force_timeout_jfs = usecs_to_jiffies(timeout_us); > > +} > ... > > +static bool linser_tx_frame_as_responder(struct linser_priv *priv, u8 id) > > +{ > > + struct lin_responder_answer *answ = &priv->respond_answ[id]; > > + struct serdev_device *serdev = priv->serdev; > > + u8 buf[LINSER_TX_BUFFER_SIZE]; > > + u8 checksum, count, n; > > + ssize_t write_len; > > + > > + mutex_lock(&priv->resp_lock); > > + > > + if (!answ->is_active) > > + goto unlock_and_exit_false; > > + > > + if (answ->is_event_frame) { > > + struct lin_responder_answer *e_answ; > > + > > + e_answ = &priv->respond_answ[answ->event_associated_id]; > > + n = min(e_answ->lf.len, LIN_MAX_DLEN); > > + if (memcmp(answ->lf.data, e_answ->lf.data, n) != 0) { > > + memcpy(answ->lf.data, e_answ->lf.data, n); > > + checksum = lin_get_checksum(LIN_FORM_PID(answ->lf.lin_id), > > + n, e_answ->lf.data, > > + answ->lf.checksum_mode); > > + answ = e_answ; > > + } else { > > + goto unlock_and_exit_false; > > Can't you simply use guard(mutex) above and avoid the error-prone > gotos/cleanup completely? OK > > > + } > > + } else { > > + checksum = answ->lf.checksum; > > + } > > + > > + count = min(answ->lf.len, LIN_MAX_DLEN); > > + memcpy(&buf[0], answ->lf.data, count); > > + buf[count] = checksum; > > + > > + mutex_unlock(&priv->resp_lock); > > + > > + write_len = serdev_device_write(serdev, buf, count + 1, 0); > > + if (write_len < count + 1) > > + return false; > > + > > + serdev_device_wait_until_sent(serdev, 0); > > + > > + return true; > > + > > +unlock_and_exit_false: > > + mutex_unlock(&priv->resp_lock); > > + return false; > > +} > > + > > +static void linser_pop_fifo(struct linser_priv *priv, size_t n) > > +{ > > + struct serdev_device *serdev = priv->serdev; > > + struct linser_rx dummy; > > + size_t ret, i; > > + > > + for (i = 0; i < n; i++) { > > + ret = kfifo_out(&priv->rx_fifo, &dummy, 1); > > Does kfifo_skip() not work for records? (I added it recently for serial.) Using kfifo_skip() greatly simplifies this function and it works for records (uses __kfifo_skip_r), tests are successful. Maybe the comment in kfifo.h could be made more clear from: "kfifo_skip - skip output data" to "kfifo_skip - skip the next fifo record" > > > + if (ret != 1) { > > + dev_err(&serdev->dev, "Failed to pop from FIFO\n"); > > + break; > > + } > > + } > > +} > Let me address these points and reroll in v3. Thanks -- Christoph
