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([2a0b:e7c0:0:107::aaaa:69]) by smtp.gmail.com with ESMTPSA id og20-20020a1709071dd400b00a5970e88670sm198140ejc.176.2024.05.02.01.44.47 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 May 2024 01:44:47 -0700 (PDT) Message-ID: <6ae3c1af-4368-4a3e-bfb5-366080048dac@kernel.org> Date: Thu, 2 May 2024 10:44:46 +0200 Precedence: bulk X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 07/12] can: Add support for serdev LIN adapters To: Christoph Fritz , Oliver Hartkopp , Marc Kleine-Budde , Vincent Mailhol , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Jiri Kosina , Benjamin Tissoires , Greg Kroah-Hartman , Sebastian Reichel , Linus Walleij Cc: Andreas Lauser , Jonathan Corbet , Pavel Pisa , linux-can@vger.kernel.org, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-input@vger.kernel.org, linux-serial@vger.kernel.org References: <20240502075534.882628-1-christoph.fritz@hexdev.de> <20240502075534.882628-8-christoph.fritz@hexdev.de> Content-Language: en-US From: Jiri Slaby Autocrypt: addr=jirislaby@kernel.org; keydata= xsFNBE6S54YBEACzzjLwDUbU5elY4GTg/NdotjA0jyyJtYI86wdKraekbNE0bC4zV+ryvH4j rrcDwGs6tFVrAHvdHeIdI07s1iIx5R/ndcHwt4fvI8CL5PzPmn5J+h0WERR5rFprRh6axhOk rSD5CwQl19fm4AJCS6A9GJtOoiLpWn2/IbogPc71jQVrupZYYx51rAaHZ0D2KYK/uhfc6neJ i0WqPlbtIlIrpvWxckucNu6ZwXjFY0f3qIRg3Vqh5QxPkojGsq9tXVFVLEkSVz6FoqCHrUTx wr+aw6qqQVgvT/McQtsI0S66uIkQjzPUrgAEtWUv76rM4ekqL9stHyvTGw0Fjsualwb0Gwdx ReTZzMgheAyoy/umIOKrSEpWouVoBt5FFSZUyjuDdlPPYyPav+hpI6ggmCTld3u2hyiHji2H cDpcLM2LMhlHBipu80s9anNeZhCANDhbC5E+NZmuwgzHBcan8WC7xsPXPaiZSIm7TKaVoOcL 9tE5aN3jQmIlrT7ZUX52Ff/hSdx/JKDP3YMNtt4B0cH6ejIjtqTd+Ge8sSttsnNM0CQUkXps w98jwz+Lxw/bKMr3NSnnFpUZaxwji3BC9vYyxKMAwNelBCHEgS/OAa3EJoTfuYOK6wT6nadm YqYjwYbZE5V/SwzMbpWu7Jwlvuwyfo5mh7w5iMfnZE+vHFwp/wARAQABzSFKaXJpIFNsYWJ5 IDxqaXJpc2xhYnlAa2VybmVsLm9yZz7CwXcEEwEIACEFAlW3RUwCGwMFCwkIBwIGFQgJCgsC BBYCAwECHgECF4AACgkQvSWxBAa0cEnVTg//TQpdIAr8Tn0VAeUjdVIH9XCFw+cPSU+zMSCH eCZoA/N6gitEcnvHoFVVM7b3hK2HgoFUNbmYC0RdcSc80pOF5gCnACSP9XWHGWzeKCARRcQR 4s5YD8I4VV5hqXcKo2DFAtIOVbHDW+0okOzcecdasCakUTr7s2fXz97uuoc2gIBB7bmHUGAH XQXHvdnCLjDjR+eJN+zrtbqZKYSfj89s/ZHn5Slug6w8qOPT1sVNGG+eWPlc5s7XYhT9z66E l5C0rG35JE4PhC+tl7BaE5IwjJlBMHf/cMJxNHAYoQ1hWQCKOfMDQ6bsEr++kGUCbHkrEFwD UVA72iLnnnlZCMevwE4hc0zVhseWhPc/KMYObU1sDGqaCesRLkE3tiE7X2cikmj/qH0CoMWe gjnwnQ2qVJcaPSzJ4QITvchEQ+tbuVAyvn9H+9MkdT7b7b2OaqYsUP8rn/2k1Td5zknUz7iF oJ0Z9wPTl6tDfF8phaMIPISYrhceVOIoL+rWfaikhBulZTIT5ihieY9nQOw6vhOfWkYvv0Dl o4GRnb2ybPQpfEs7WtetOsUgiUbfljTgILFw3CsPW8JESOGQc0Pv8ieznIighqPPFz9g+zSu Ss/rpcsqag5n9rQp/H3WW5zKUpeYcKGaPDp/vSUovMcjp8USIhzBBrmI7UWAtuedG9prjqfO wU0ETpLnhgEQAM+cDWLL+Wvc9cLhA2OXZ/gMmu7NbYKjfth1UyOuBd5emIO+d4RfFM02XFTI t4MxwhAryhsKQQcA4iQNldkbyeviYrPKWjLTjRXT5cD2lpWzr+Jx7mX7InV5JOz1Qq+P+nJW YIBjUKhI03ux89p58CYil24Zpyn2F5cX7U+inY8lJIBwLPBnc9Z0An/DVnUOD+0wIcYVnZAK DiIXODkGqTg3fhZwbbi+KAhtHPFM2fGw2VTUf62IHzV+eBSnamzPOBc1XsJYKRo3FHNeLuS8 f4wUe7bWb9O66PPFK/RkeqNX6akkFBf9VfrZ1rTEKAyJ2uqf1EI1olYnENk4+00IBa+BavGQ 8UW9dGW3nbPrfuOV5UUvbnsSQwj67pSdrBQqilr5N/5H9z7VCDQ0dhuJNtvDSlTf2iUFBqgk 3smln31PUYiVPrMP0V4ja0i9qtO/TB01rTfTyXTRtqz53qO5dGsYiliJO5aUmh8swVpotgK4 /57h3zGsaXO9PGgnnAdqeKVITaFTLY1ISg+Ptb4KoliiOjrBMmQUSJVtkUXMrCMCeuPDGHo7 39Xc75lcHlGuM3yEB//htKjyprbLeLf1y4xPyTeeF5zg/0ztRZNKZicgEmxyUNBHHnBKHQxz 1j+mzH0HjZZtXjGu2KLJ18G07q0fpz2ZPk2D53Ww39VNI/J9ABEBAAHCwV8EGAECAAkFAk6S 54YCGwwACgkQvSWxBAa0cEk3tRAAgO+DFpbyIa4RlnfpcW17AfnpZi9VR5+zr496n2jH/1ld wRO/S+QNSA8qdABqMb9WI4BNaoANgcg0AS429Mq0taaWKkAjkkGAT7mD1Q5PiLr06Y/+Kzdr 90eUVneqM2TUQQbK+Kh7JwmGVrRGNqQrDk+gRNvKnGwFNeTkTKtJ0P8jYd7P1gZb9Fwj9YLx jhn/sVIhNmEBLBoI7PL+9fbILqJPHgAwW35rpnq4f/EYTykbk1sa13Tav6btJ+4QOgbcezWI wZ5w/JVfEJW9JXp3BFAVzRQ5nVrrLDAJZ8Y5ioWcm99JtSIIxXxt9FJaGc1Bgsi5K/+dyTKL wLMJgiBzbVx8G+fCJJ9YtlNOPWhbKPlrQ8+AY52Aagi9WNhe6XfJdh5g6ptiOILm330mkR4g W6nEgZVyIyTq3ekOuruftWL99qpP5zi+eNrMmLRQx9iecDNgFr342R9bTDlb1TLuRb+/tJ98 f/bIWIr0cqQmqQ33FgRhrG1+Xml6UXyJ2jExmlO8JljuOGeXYh6ZkIEyzqzffzBLXZCujlYQ DFXpyMNVJ2ZwPmX2mWEoYuaBU0JN7wM+/zWgOf2zRwhEuD3A2cO2PxoiIfyUEfB9SSmffaK/ S4xXoB6wvGENZ85Hg37C7WDNdaAt6Xh2uQIly5grkgvWppkNy4ZHxE+jeNsU7tg= In-Reply-To: <20240502075534.882628-8-christoph.fritz@hexdev.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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 > +#include > +#include > +#include > +#include > +#include What do you need kernel.h for? You should explicitly require what you need (you apparently do), so kernel.h should not be needed. > +#include > +#include > +#include > +#include > +#include > +#include > +#include Might be eaier to maintain if you sort them. > +#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 :) > + 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? > + 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? > + } > + } 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.) > + if (ret != 1) { > + dev_err(&serdev->dev, "Failed to pop from FIFO\n"); > + break; > + } > + } > +} thanks, -- js suse labs