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[185.219.167.24]) by smtp.gmail.com with ESMTPSA id m10-20020a50998a000000b004e48f8df7e2sm15805828edb.72.2023.03.28.02.23.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 28 Mar 2023 02:23:46 -0700 (PDT) Message-ID: Date: Tue, 28 Mar 2023 11:23:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Content-Language: en-US To: Jacky Huang , robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, lee@kernel.org, mturquette@baylibre.com, sboyd@kernel.org, p.zabel@pengutronix.de, gregkh@linuxfoundation.org Cc: devicetree@vger.kernel.org, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, linux-serial@vger.kernel.org, arnd@arndb.de, schung@nuvoton.com, mjchen@nuvoton.com, Jacky Huang References: <20230328021912.177301-1-ychuang570808@gmail.com> <20230328021912.177301-12-ychuang570808@gmail.com> From: Jiri Slaby Subject: Re: [PATCH v6 11/12] tty: serial: Add Nuvoton ma35d1 serial driver support In-Reply-To: <20230328021912.177301-12-ychuang570808@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On 28. 03. 23, 4:19, Jacky Huang wrote: > +static void transmit_chars(struct uart_ma35d1_port *up) > +{ > + struct circ_buf *xmit = &up->port.state->xmit; > + int count; > + u8 ch; > + > + if (uart_tx_stopped(&up->port)) { > + ma35d1serial_stop_tx(&up->port); > + return; > + } > + if (uart_circ_empty(xmit)) { > + __stop_tx(up); > + return; > + } Why is this necessary? > + count = UART_FIFO_DEPTH - ((serial_in(up, UART_REG_FSR) & FSR_TXPTR_MSK) >> 16); > + > + uart_port_tx_limited(&up->port, ch, count, > + !(serial_in(up, UART_REG_FSR) & FSR_TX_FULL), > + serial_out(up, UART_REG_THR, ch), > + ({})); > + > + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) > + uart_write_wakeup(&up->port); > + > + if (uart_circ_empty(xmit)) > + __stop_tx(up); uart_port_tx_limited() should take care about the above and this too, right? > +} ... > +static void receive_chars(struct uart_ma35d1_port *up) > +{ > + u8 flag; > + u32 fsr; > + unsigned int ch; Shouldn't ch be u8 too? > + int max_count = 256; > + > + fsr = serial_in(up, UART_REG_FSR); > + do { > + flag = TTY_NORMAL; > + up->port.icount.rx++; > + > + if (unlikely(fsr & (FSR_BIF | FSR_FEF | FSR_PEF | FSR_RX_OVER_IF))) { > + if (fsr & FSR_BIF) { > + up->port.icount.brk++; > + if (uart_handle_break(&up->port)) > + continue; > + } > + if (fsr & FSR_FEF) > + up->port.icount.frame++; > + if (fsr & FSR_PEF) > + up->port.icount.parity++; > + if (fsr & FSR_RX_OVER_IF) > + up->port.icount.overrun++; > + > + serial_out(up, UART_REG_FSR, fsr & > + (FSR_BIF | FSR_FEF | FSR_PEF | FSR_RX_OVER_IF)); > + > + if (fsr & FSR_BIF) > + flag = TTY_BREAK; > + else if (fsr & FSR_PEF) > + flag = TTY_PARITY; > + else if (fsr & FSR_FEF) > + flag = TTY_FRAME; > + } > + > + ch = serial_in(up, UART_REG_RBR); > + if (uart_handle_sysrq_char(&up->port, ch)) > + continue; > + > + spin_lock(&up->port.lock); > + uart_insert_char(&up->port, fsr, FSR_RX_OVER_IF, ch, flag); > + spin_unlock(&up->port.lock); > + > + fsr = serial_in(up, UART_REG_FSR); > + } while (!(fsr & FSR_RX_EMPTY) && (max_count-- > 0)); > + > + spin_lock(&up->port.lock); > + tty_flip_buffer_push(&up->port.state->port); > + spin_unlock(&up->port.lock); > +} ... > +static int ma35d1serial_remove(struct platform_device *dev) > +{ > + struct uart_port *port = platform_get_drvdata(dev); > + > + if (port) { Can this ever be NULL? > + uart_remove_one_port(&ma35d1serial_reg, port); > + free_irq(port->irq, port); > + } > + return 0; > +} > + > +static int ma35d1serial_suspend(struct platform_device *dev, pm_message_t state) > +{ > + int i; > + struct uart_ma35d1_port *up; > + > + if (dev->dev.of_node) > + i = of_alias_get_id(dev->dev.of_node, "serial"); > + if (i < 0) { > + dev_err(&dev->dev, "failed to get alias/pdev id, errno %d\n", i); > + return i; > + } > + up = &ma35d1serial_ports[i]; platform_get_drvdata(dev) ? > + if (i == 0) { > + up->console_baud_rate = serial_in(up, UART_REG_BAUD); > + up->console_line = serial_in(up, UART_REG_LCR); > + up->console_int = serial_in(up, UART_REG_IER); > + } > + return 0; > +} > + > +static int ma35d1serial_resume(struct platform_device *dev) > +{ > + int i; > + struct uart_ma35d1_port *up; > + > + if (dev->dev.of_node) > + i = of_alias_get_id(dev->dev.of_node, "serial"); > + if (i < 0) { > + dev_err(&dev->dev, "failed to get alias/pdev id, errno %d\n", i); > + return i; > + } > + up = &ma35d1serial_ports[i]; > + if (i == 0) { > + serial_out(up, UART_REG_BAUD, up->console_baud_rate); > + serial_out(up, UART_REG_LCR, up->console_line); > + serial_out(up, UART_REG_IER, up->console_int); > + } > + return 0; > +} No uart_suspend_port()/uart_resume_port()? You don't wait for transmitter to be empty in suspend. You don't stop tx etc. > +static struct platform_driver ma35d1serial_driver = { > + .probe = ma35d1serial_probe, > + .remove = ma35d1serial_remove, > + .suspend = ma35d1serial_suspend, > + .resume = ma35d1serial_resume, > + .driver = { > + .name = "ma35d1-uart", > + .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(ma35d1_serial_of_match), > + }, > +}; > + > +static int __init ma35d1serial_init(void) > +{ > + int ret; > + > + ret = uart_register_driver(&ma35d1serial_reg); > + if (ret) > + return ret; > + ret = platform_driver_register(&ma35d1serial_driver); > + if (ret) > + uart_unregister_driver(&ma35d1serial_reg); > + return ret; > +} > + > +static void __exit ma35d1serial_exit(void) > +{ > + platform_driver_unregister(&ma35d1serial_driver); > + uart_unregister_driver(&ma35d1serial_reg); > +} > + > +module_init(ma35d1serial_init); > +module_exit(ma35d1serial_exit); > + > +MODULE_LICENSE("GPL"); > +MODULE_DESCRIPTION("MA35D1 serial driver"); > +MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR); Why is this needed? How are other platform drivers autoloaded? thanks, -- js suse labs