Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751650AbWHSJEi (ORCPT ); Sat, 19 Aug 2006 05:04:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751645AbWHSJEi (ORCPT ); Sat, 19 Aug 2006 05:04:38 -0400 Received: from caramon.arm.linux.org.uk ([217.147.92.249]:56329 "EHLO caramon.arm.linux.org.uk") by vger.kernel.org with ESMTP id S1751268AbWHSJEh (ORCPT ); Sat, 19 Aug 2006 05:04:37 -0400 Date: Sat, 19 Aug 2006 10:04:27 +0100 From: Russell King To: Vitaly Wool Cc: jean-paul.saman@philips.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH/RFC] UART driver for PNX8550/8950 revised Message-ID: <20060819090427.GB25767@flint.arm.linux.org.uk> Mail-Followup-To: Vitaly Wool , jean-paul.saman@philips.com, linux-kernel@vger.kernel.org References: <20060819122600.000017e6.vitalywool@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060819122600.000017e6.vitalywool@gmail.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11371 Lines: 390 On Sat, Aug 19, 2006 at 12:26:00PM +0400, Vitaly Wool wrote: > Hello Russell, > > please find the patch that adds PNX8xxx UART support with your > comments taken into account inlined. On the whole, it's good, but still not quite there yet. There's a couple of comments that seem to have been missed from last time around - if you don't understand them or know how to correct them, feel free to discuss them. I've picked up a few more points as well. > + > +#include linux/config.h is not required anymore. > + > +#if defined(CONFIG_SERIAL_PNX8XXX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ) > +#define SUPPORT_SYSRQ > +#endif > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include serial_pnx8xxx.h just contains structure and register definitions for this driver - wouldn't it make more sense for it to be in drivers/serial along side this driver? > + > +#include > +#include > + > +#include What is uart.h? It isn't in this patch, neither is it part of mainline. > +static void > +pnx8xxx_rx_chars(struct pnx8xxx_port *sport, struct pt_regs *regs) > +{ > + struct tty_struct *tty = sport->port.info->tty; > + unsigned int status, ch, flg; > + > + status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) | > + ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT)); > + while (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFIFO)) { > + ch = serial_in(sport, PNX8XXX_FIFO); > + > + sport->port.icount.rx++; > + > + flg = TTY_NORMAL; > + > + /* > + * note that the error handling code is > + * out of the main execution path > + */ > + if (status & (FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE | > + PNX8XXX_UART_FIFO_RXPAR) | > + ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN))) { > + if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR)) > + sport->port.icount.parity++; > + else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE)) > + sport->port.icount.frame++; > + if (status & ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN)) > + sport->port.icount.overrun++; Still not using read_status_mask here, as detailed in my previous review. status &= sport->port.read_status_mask; is what's missing. > + > + if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR)) > + flg = TTY_PARITY; > + else if (status & FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE)) > + flg = TTY_FRAME; > + > +#ifdef SUPPORT_SYSRQ > + sport->port.sysrq = 0; > +#endif > + } Weird indentation - is this close brace part of the while loop (as its indentation suggests) or the if () clause (as it seems to be in reality). > + > + if (uart_handle_sysrq_char(&sport->port, ch, regs)) > + goto ignore_char; > + > + uart_insert_char(&sport->port, status, > + ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN), ch, flg); > + > + ignore_char: > + serial_out(sport, PNX8XXX_LCR, serial_in(sport, PNX8XXX_LCR) | > + PNX8XXX_UART_LCR_RX_NEXT); > + status = FIFO_TO_SM(serial_in(sport, PNX8XXX_FIFO)) | > + ISTAT_TO_SM(serial_in(sport, PNX8XXX_ISTAT)); > + } > + tty_flip_buffer_push(tty); > +} ... > +static irqreturn_t pnx8xxx_int(int irq, void *dev_id, struct pt_regs *regs) > +{ > + struct pnx8xxx_port *sport = dev_id; > + unsigned int status; > + > + spin_lock(&sport->port.lock); > + /* Get the interrupts */ > + status = serial_in(sport, PNX8XXX_ISTAT) & serial_in(sport, PNX8XXX_IEN); > + > + /* RX Receiver Holding Register Overrun */ > + if (status & PNX8XXX_UART_INT_RXOVRN) { > + sport->port.icount.overrun++; > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_RXOVRN); > + } > + > + /* RX Frame Error */ > + if (status & PNX8XXX_UART_INT_FRERR) { > + sport->port.icount.frame++; Aren't frame/parity/overrun errors handled in your receive function? Does this mean that if you have one framing error, you increment icount.frame twice? Please check the behaviour of your uart. > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_FRERR); > + } > + > + /* Break signal received */ > + if (status & PNX8XXX_UART_INT_BREAK) { > + sport->port.icount.brk++; > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_BREAK); > + uart_handle_break(&sport->port); > + } > + > + /* RX Parity Error */ > + if (status & PNX8XXX_UART_INT_PARITY) { > + sport->port.icount.parity++; > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_PARITY); > + } > + > + /* Byte received */ > + if (status & PNX8XXX_UART_INT_RX) { > + pnx8xxx_rx_chars(sport, regs); > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_RX); > + } > + > + /* TX holding register empty - transmit a byte */ > + if (status & PNX8XXX_UART_INT_TX) { > + pnx8xxx_tx_chars(sport); > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_TX); > + } > + > + /* TX shift register and holding register empty */ > + if (status & PNX8XXX_UART_INT_EMPTY) { > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_EMPTY); > + } > + > + /* Receiver time out */ > + if (status & PNX8XXX_UART_INT_RCVTO) { > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_RCVTO); > + } > + spin_unlock(&sport->port.lock); > + return IRQ_HANDLED; > +} ... > +static void pnx8xxx_shutdown(struct uart_port *port) > +{ > + struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port; > + > + /* > + * Stop our timer. > + */ > + del_timer_sync(&sport->timer); > + > + /* > + * Disable all interrupts, port and break condition. > + */ > + serial_out(sport, PNX8XXX_IEN, 0); This comment's not correct - where is the break condition disabled? I thought it might be in the next serial_out() but it seems to be missing from there as well? > + > + /* > + * Reset the Tx and Rx FIFOS > + */ > + serial_out(sport, PNX8XXX_LCR, serial_in(sport, PNX8XXX_LCR) | > + PNX8XXX_UART_LCR_TX_RST | > + PNX8XXX_UART_LCR_RX_RST); > + > + /* > + * Clear all interrupts > + */ > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_ALLRX | > + PNX8XXX_UART_INT_ALLTX); > + > + /* > + * Free the interrupt > + */ > + free_irq(sport->port.irq, sport); > +} > + > +static void > +pnx8xxx_set_termios(struct uart_port *port, struct termios *termios, > + struct termios *old) > +{ > + struct pnx8xxx_port *sport = (struct pnx8xxx_port *)port; > + unsigned long flags; > + unsigned int lcr_fcr, old_ien, baud, quot; > + unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8; > + > + /* > + * We only support CS7 and CS8. > + */ > + while ((termios->c_cflag & CSIZE) != CS7 && > + (termios->c_cflag & CSIZE) != CS8) { > + termios->c_cflag &= ~CSIZE; > + termios->c_cflag |= old_csize; > + old_csize = CS8; > + } > + > + if ((termios->c_cflag & CSIZE) == CS8) > + lcr_fcr = PNX8XXX_UART_LCR_8BIT; > + else > + lcr_fcr = 0; > + > + if (termios->c_cflag & CSTOPB) > + lcr_fcr |= PNX8XXX_UART_LCR_2STOPB; > + if (termios->c_cflag & PARENB) { > + lcr_fcr |= PNX8XXX_UART_LCR_PAREN; > + if (!(termios->c_cflag & PARODD)) > + lcr_fcr |= PNX8XXX_UART_LCR_PAREVN; > + } > + > + /* > + * Ask the core to calculate the divisor for us. > + */ > + baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); > + quot = uart_get_divisor(port, baud); > + > + spin_lock_irqsave(&sport->port.lock, flags); > + > + sport->port.read_status_mask = ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN) | > + ISTAT_TO_SM(PNX8XXX_UART_INT_EMPTY) | > + ISTAT_TO_SM(PNX8XXX_UART_INT_RX); > + if (termios->c_iflag & INPCK) > + sport->port.read_status_mask |= > + FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) | > + FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR); > + if (termios->c_iflag & (BRKINT | PARMRK)) > + sport->port.read_status_mask |= > + ISTAT_TO_SM(PNX8XXX_UART_INT_BREAK); > + > + /* > + * Characters to ignore > + */ > + sport->port.ignore_status_mask = 0; > + if (termios->c_iflag & IGNPAR) > + sport->port.ignore_status_mask |= > + FIFO_TO_SM(PNX8XXX_UART_FIFO_RXFE) | > + FIFO_TO_SM(PNX8XXX_UART_FIFO_RXPAR); > + if (termios->c_iflag & IGNBRK) { > + sport->port.ignore_status_mask |= > + ISTAT_TO_SM(PNX8XXX_UART_INT_BREAK); > + /* > + * If we're ignoring parity and break indicators, > + * ignore overruns too (for real raw support). > + */ > + if (termios->c_iflag & IGNPAR) > + sport->port.ignore_status_mask |= > + ISTAT_TO_SM(PNX8XXX_UART_INT_RXOVRN); > + } How about CREAD support? > + > + del_timer_sync(&sport->timer); > + > + /* > + * Update the per-port timeout. > + */ > + uart_update_timeout(port, termios->c_cflag, baud); > + > + /* > + * disable interrupts and drain transmitter > + */ > + old_ien = serial_in(sport, PNX8XXX_IEN); > + serial_out(sport, PNX8XXX_IEN, old_ien & ~(PNX8XXX_UART_INT_ALLTX | > + PNX8XXX_UART_INT_ALLRX)); > + > + while (serial_in(sport, PNX8XXX_FIFO) & PNX8XXX_UART_FIFO_TXFIFO_STA) > + barrier(); > + > + /* then, disable everything */ > + serial_out(sport, PNX8XXX_IEN, 0); > + > + /* Reset the Rx and Tx FIFOs too */ > + lcr_fcr |= PNX8XXX_UART_LCR_TX_RST; > + lcr_fcr |= PNX8XXX_UART_LCR_RX_RST; > + > + /* set the parity, stop bits and data size */ > + serial_out(sport, PNX8XXX_LCR, lcr_fcr); > + > + /* set the baud rate */ > + quot -= 1; > + serial_out(sport, PNX8XXX_BAUD, quot); > + > + serial_out(sport, PNX8XXX_ICLR, -1); > + > + serial_out(sport, PNX8XXX_IEN, old_ien); > + > + if (UART_ENABLE_MS(&sport->port, termios->c_cflag)) > + pnx8xxx_enable_ms(&sport->port); > + > + spin_unlock_irqrestore(&sport->port.lock, flags); > +} ... > +/* > + * Interrupts are disabled on entering > + */ > +static void > +pnx8xxx_console_write(struct console *co, const char *s, unsigned int count) > +{ > + struct pnx8xxx_port *sport = &pnx8xxx_ports[co->index]; > + unsigned int old_ien, status, i; > + > + /* > + * First, save IEN and then disable interrupts > + */ > + old_ien = serial_in(sport, PNX8XXX_IEN); > + serial_out(sport, PNX8XXX_IEN, old_ien & ~(PNX8XXX_UART_INT_ALLTX | > + PNX8XXX_UART_INT_ALLRX)); > + > + /* > + * Now, do each character > + */ > + for (i = 0; i < count; i++) { > + do { > + /* Wait for UART_TX register to empty */ > + status = serial_in(sport, PNX8XXX_FIFO); > + } while (status & PNX8XXX_UART_FIFO_TXFIFO); > + serial_out(sport, PNX8XXX_FIFO, s[i]); > + if (s[i] == '\n') { > + do { > + status = serial_in(sport, PNX8XXX_FIFO); > + } while (status & PNX8XXX_UART_FIFO_TXFIFO); > + serial_out(sport, PNX8XXX_FIFO, '\r'); > + } > + } Still not using uart_console_write(). > + > + /* > + * Finally, wait for transmitter to become empty > + * and restore IEN > + */ > + do { > + /* Wait for UART_TX register to empty */ > + status = serial_in(sport, PNX8XXX_FIFO); > + } while (status & PNX8XXX_UART_FIFO_TXFIFO); > + > + /* Clear TX and EMPTY interrupt */ > + serial_out(sport, PNX8XXX_ICLR, PNX8XXX_UART_INT_TX | > + PNX8XXX_UART_INT_EMPTY); > + > + serial_out(sport, PNX8XXX_IEN, old_ien); > +} -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/