From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp14.mail.ru ([94.100.176.91]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TPZSI-0003u2-Rh for barebox@lists.infradead.org; Sat, 20 Oct 2012 13:51:12 +0000 Date: Sat, 20 Oct 2012 17:50:58 +0400 From: Alexander Shiyan Message-Id: <20121020175058.7a9270e287ea94ed5df84925@mail.ru> In-Reply-To: <20121016213956.GH27665@pengutronix.de> References: <1350318405-20081-1-git-send-email-shc_work@mail.ru> <1350318405-20081-2-git-send-email-shc_work@mail.ru> <20121015175852.GC5803@game.jcrosoft.org> <20121015215839.GR27665@pengutronix.de> <20121016080801.GF5803@game.jcrosoft.org> <20121016213956.GH27665@pengutronix.de> Mime-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH v2 2/3] ARM: clps711x: Add serial driver To: Sascha Hauer Cc: barebox@lists.infradead.org On Tue, 16 Oct 2012 23:39:56 +0200 Sascha Hauer wrote: ... > > > We already had this. This SoC has a very strange register layout. The > > > registers for the UARTs are spread around the SoC and the registers > > > are not even exclusively used for the UARTs. They have bits which are > > > also used for the timer and other stuff. > > use the device id to select the register is wrong > > > > we need to pass the register via resource (without request) or platform data > > > > > > > > +static int clps711x_tstc(struct console_device *cdev) > > > > > +{ > > > > > + return !(readl(SYSFLG(cdev->dev->id)) & SYSFLG_URXFE); > > > > factorise those pull status as > > > > > > > > status int xxx(data, mask) {} > > > > > > I don'r understand this. This is a single register read, there's not > > > much to factorize and the code is easy to read. > > he use the code at a least 2 place > > Testing for a bit like above is done a thousand times all around the > kernel and barebox. There is nothing to factorize. The way Alexander did > it is perfectly fine. Please look on new version below. If it looks OK, I will make complete v2 patch. Thanks! /* * Simple CLPS711X serial driver * * (C) Copyright 2012 Alexander Shiyan * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of * the License, or (at your option) any later version. */ #include #include #include #include #include #include struct clps711x_uart { void __iomem *UBRLCR; void __iomem *SYSCON; void __iomem *SYSFLG; void __iomem *UARTDR; struct clk *uart_clk; struct console_device cdev; }; static int clps711x_setbaudrate(struct console_device *cdev, int baudrate) { struct clps711x_uart *s = cdev->dev->priv; int divisor; u32 tmp; divisor = (clk_get_rate(s->uart_clk) / 16) / baudrate; tmp = readl(s->UBRLCR) & ~UBRLCR_BAUD_MASK; tmp |= divisor - 1; writel(tmp, s->UBRLCR); return 0; } static void clps711x_init_port(struct console_device *cdev) { struct clps711x_uart *s = cdev->dev->priv; u32 tmp; /* Disable the UART */ writel(readl(s->SYSCON) & ~SYSCON_UARTEN, s->SYSCON); /* Setup Line Control Register */ tmp = readl(s->UBRLCR) & UBRLCR_BAUD_MASK; tmp |= UBRLCR_FIFOEN | UBRLCR_WRDLEN8; /* FIFO on, 8N1 mode */ writel(tmp, s->UBRLCR); /* Set default baudrate on initialization */ clps711x_setbaudrate(cdev, CONFIG_BAUDRATE); /* Enable the UART */ writel(readl(s->SYSCON) | SYSCON_UARTEN, s->SYSCON); } static void clps711x_putc(struct console_device *cdev, char c) { struct clps711x_uart *s = cdev->dev->priv; /* Wait until there is space in the FIFO */ while (readl(s->SYSFLG) & SYSFLG_UTXFF) barrier(); /* Send the character */ writew(c, s->UARTDR); } static int clps711x_getc(struct console_device *cdev) { struct clps711x_uart *s = cdev->dev->priv; u16 data; /* Wait until there is data in the FIFO */ while (readl(s->SYSFLG) & SYSFLG_URXFE) barrier(); data = readw(s->UARTDR); /* Check for an error flag */ if (data & (UARTDR_FRMERR | UARTDR_PARERR | UARTDR_OVERR)) return -1; return (int)data; } static int clps711x_tstc(struct console_device *cdev) { struct clps711x_uart *s = cdev->dev->priv; return !(readl(s->SYSFLG) & SYSFLG_URXFE); } static void clps711x_flush(struct console_device *cdev) { struct clps711x_uart *s = cdev->dev->priv; while (readl(s->SYSFLG) & SYSFLG_UBUSY) barrier(); } static int clps711x_probe(struct device_d *dev) { struct clps711x_uart *s; BUG_ON(dev->num_resources != 4); s = xzalloc(sizeof(struct clps711x_uart)); s->uart_clk = clk_get(dev, NULL); BUG_ON(!s->uart_clk); s->UBRLCR = dev_get_mem_region(dev, 0); s->SYSCON = dev_get_mem_region(dev, 1); s->SYSFLG = dev_get_mem_region(dev, 2); s->UARTDR = dev_get_mem_region(dev, 3); dev->priv = s; s->cdev.dev = dev; s->cdev.f_caps = CONSOLE_STDIN | CONSOLE_STDOUT | CONSOLE_STDERR; s->cdev.tstc = clps711x_tstc; s->cdev.putc = clps711x_putc; s->cdev.getc = clps711x_getc; s->cdev.flush = clps711x_flush; s->cdev.setbrg = clps711x_setbaudrate; clps711x_init_port(&s->cdev); return console_register(&s->cdev); } static void clps711x_remove(struct device_d *dev) { struct clps711x_uart *s = dev->priv; clps711x_flush(&s->cdev); console_unregister(&s->cdev); free(s); } static struct driver_d clps711x_driver = { .name = "clps711x_serial", .probe = clps711x_probe, .remove = clps711x_remove, }; static int clps711x_init(void) { return platform_driver_register(&clps711x_driver); } console_initcall(clps711x_init); -- Alexander Shiyan _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox