From patchwork Mon Sep 26 19:07:12 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: thomas.abraham@linaro.org X-Patchwork-Id: 4342 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 797C723F57 for ; Mon, 26 Sep 2011 19:07:37 +0000 (UTC) Received: from mail-fx0-f52.google.com (mail-fx0-f52.google.com [209.85.161.52]) by fiordland.canonical.com (Postfix) with ESMTP id 6A8B3A1860E for ; Mon, 26 Sep 2011 19:07:37 +0000 (UTC) Received: by mail-fx0-f52.google.com with SMTP id 23so8789249fxe.11 for ; Mon, 26 Sep 2011 12:07:37 -0700 (PDT) Received: by 10.223.30.151 with SMTP id u23mr1654615fac.122.1317064057253; Mon, 26 Sep 2011 12:07:37 -0700 (PDT) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.152.3.234 with SMTP id f10cs48416laf; Mon, 26 Sep 2011 12:07:37 -0700 (PDT) Received: by 10.236.175.105 with SMTP id y69mr3327195yhl.115.1317064055680; Mon, 26 Sep 2011 12:07:35 -0700 (PDT) Received: from mailout4.samsung.com (mailout4.samsung.com. [203.254.224.34]) by mx.google.com with ESMTP id w27si1618811yhl.66.2011.09.26.12.07.34; Mon, 26 Sep 2011 12:07:35 -0700 (PDT) Received-SPF: neutral (google.com: 203.254.224.34 is neither permitted nor denied by best guess record for domain of thomas.abraham@linaro.org) client-ip=203.254.224.34; Authentication-Results: mx.google.com; spf=neutral (google.com: 203.254.224.34 is neither permitted nor denied by best guess record for domain of thomas.abraham@linaro.org) smtp.mail=thomas.abraham@linaro.org Received: from epcpsbgm1.samsung.com (mailout4.samsung.com [203.254.224.34]) by mailout4.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTP id <0LS500HZL94F7IJ0@mailout4.samsung.com> for patches@linaro.org; Tue, 27 Sep 2011 04:07:33 +0900 (KST) X-AuditID: cbfee61a-b7cf1ae00000208e-6a-4e80cd75c707 Received: from epmmp2 ( [203.254.227.17]) by epcpsbgm1.samsung.com (MMPCPMTA) with SMTP id 1E.37.08334.57DC08E4; Tue, 27 Sep 2011 04:07:33 +0900 (KST) Received: from localhost.localdomain ([107.108.73.37]) by mmp2.samsung.com (Oracle Communications Messaging Exchange Server 7u4-19.01 64bit (built Sep 7 2010)) with ESMTPA id <0LS5008Q69489390@mmp2.samsung.com> for patches@linaro.org; Tue, 27 Sep 2011 04:07:33 +0900 (KST) From: Thomas Abraham To: linux-serial@vger.kernel.org, devicetree-discuss@lists.ozlabs.org Cc: linux-arm-kernel@lists.infradead.org, alan@linux.intel.com, grant.likely@secretlab.ca, linux-samsung-soc@vger.kernel.org, kgene.kim@samsung.com, ben-linux@fluff.org, patches@linaro.org Subject: [PATCH 3/9] serial: samsung: switch to clkdev based clock lookup Date: Tue, 27 Sep 2011 00:37:12 +0530 Message-id: <1317064038-32428-4-git-send-email-thomas.abraham@linaro.org> X-Mailer: git-send-email 1.6.6.rc2 In-reply-to: <1317064038-32428-1-git-send-email-thomas.abraham@linaro.org> References: <1317064038-32428-1-git-send-email-thomas.abraham@linaro.org> X-Brightmail-Tracker: AAAAAA== Instead of using clock names supplied in platform data, use a generic clock name 'clk_uart_baud' to look up clocks. The platform code should register clocks with the name 'clk_uart_baud' which can be used by the baud rate generator. The clock lookup and selection of the best clock as baud rate clock is reworked. Cc: Ben Dooks Signed-off-by: Thomas Abraham --- arch/arm/plat-samsung/include/plat/regs-serial.h | 5 + drivers/tty/serial/samsung.c | 207 +++++++++------------- drivers/tty/serial/samsung.h | 4 + 3 files changed, 95 insertions(+), 121 deletions(-) diff --git a/arch/arm/plat-samsung/include/plat/regs-serial.h b/arch/arm/plat-samsung/include/plat/regs-serial.h index 7207348..b493d8d 100644 --- a/arch/arm/plat-samsung/include/plat/regs-serial.h +++ b/arch/arm/plat-samsung/include/plat/regs-serial.h @@ -222,6 +222,10 @@ #define S5PV210_UFSTAT_RXSHIFT (0) #define NO_NEED_CHECK_CLKSRC 1 +#define S3C2410_UCON_CLKSEL0 (1 << 0) +#define S3C2410_UCON_CLKSEL1 (1 << 1) +#define S3C2410_UCON_CLKSEL2 (1 << 2) +#define S3C2410_UCON_CLKSEL3 (1 << 3) #ifndef __ASSEMBLY__ @@ -257,6 +261,7 @@ struct s3c2410_uartcfg { unsigned char unused; unsigned short flags; upf_t uart_flags; /* default uart flags */ + unsigned int clk_sel; unsigned int has_fracval; diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index fc242b2..dc5a4ed 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -49,6 +49,7 @@ #include #include +#include #include "samsung.h" @@ -558,133 +559,98 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level, * */ +#define MAX_CLK_NAME_LENGTH 15 -#define MAX_CLKS (8) - -static struct s3c24xx_uart_clksrc tmp_clksrc = { - .name = "pclk", - .min_baud = 0, - .max_baud = 0, - .divisor = 1, -}; - -static inline int -s3c24xx_serial_getsource(struct uart_port *port, struct s3c24xx_uart_clksrc *c) +static inline int s3c24xx_serial_getsource(struct uart_port *port) { struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port); + unsigned int ucon; - return (info->get_clksrc)(port, c); -} - -static inline int -s3c24xx_serial_setsource(struct uart_port *port, struct s3c24xx_uart_clksrc *c) -{ - struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port); + if (info->num_clks == 1) + return 0; - return (info->set_clksrc)(port, c); + ucon = rd_regl(port, S3C2410_UCON); + ucon &= info->clksel_mask; + return ucon >> info->clksel_shift; } -struct baud_calc { - struct s3c24xx_uart_clksrc *clksrc; - unsigned int calc; - unsigned int divslot; - unsigned int quot; - struct clk *src; -}; - -static int s3c24xx_serial_calcbaud(struct baud_calc *calc, - struct uart_port *port, - struct s3c24xx_uart_clksrc *clksrc, - unsigned int baud) +static void s3c24xx_serial_setsource(struct uart_port *port, + unsigned int clk_sel) { - struct s3c24xx_uart_port *ourport = to_ourport(port); - unsigned long rate; - - calc->src = clk_get(port->dev, clksrc->name); - if (calc->src == NULL || IS_ERR(calc->src)) - return 0; - - rate = clk_get_rate(calc->src); - rate /= clksrc->divisor; + struct s3c24xx_uart_info *info = s3c24xx_port_to_info(port); + unsigned int ucon; - calc->clksrc = clksrc; + if (info->num_clks == 1) + return; - if (ourport->info->has_divslot) { - unsigned long div = rate / baud; - - /* The UDIVSLOT register on the newer UARTs allows us to - * get a divisor adjustment of 1/16th on the baud clock. - * - * We don't keep the UDIVSLOT value (the 16ths we calculated - * by not multiplying the baud by 16) as it is easy enough - * to recalculate. - */ - - calc->quot = div / 16; - calc->calc = rate / div; - } else { - calc->quot = (rate + (8 * baud)) / (16 * baud); - calc->calc = (rate / (calc->quot * 16)); - } + ucon = rd_regl(port, S3C2410_UCON); + if ((ucon & info->clksel_mask) >> info->clksel_shift == clk_sel) + return; - calc->quot--; - return 1; + ucon &= ~info->clksel_mask; + ucon |= clk_sel << info->clksel_shift; + wr_regl(port, S3C2410_UCON, ucon); } -static unsigned int s3c24xx_serial_getclk(struct uart_port *port, - struct s3c24xx_uart_clksrc **clksrc, - struct clk **clk, - unsigned int baud) +static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport, + unsigned int req_baud, struct clk **best_clk, + unsigned int *clk_num) { - struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port); - struct s3c24xx_uart_clksrc *clkp; - struct baud_calc res[MAX_CLKS]; - struct baud_calc *resptr, *best, *sptr; - int i; - - clkp = cfg->clocks; - best = NULL; - - if (cfg->clocks_size < 2) { - if (cfg->clocks_size == 0) - clkp = &tmp_clksrc; - - s3c24xx_serial_calcbaud(res, port, clkp, baud); - best = res; - resptr = best + 1; - } else { - resptr = res; - - for (i = 0; i < cfg->clocks_size; i++, clkp++) { - if (s3c24xx_serial_calcbaud(resptr, port, clkp, baud)) - resptr++; + struct s3c24xx_uart_info *info = ourport->info; + struct clk *clk; + unsigned long rate; + unsigned int cnt, baud, quot, clk_sel, best_quot = 0; + char clkname[MAX_CLK_NAME_LENGTH]; + int calc_deviation, deviation = (1 << 30) - 1; + + *best_clk = NULL; + clk_sel = (ourport->cfg->clk_sel) ? ourport->cfg->clk_sel : + ourport->info->def_clk_sel; + for (cnt = 0; cnt < info->num_clks; cnt++) { + if (!(clk_sel & (1 << cnt))) + continue; + + sprintf(clkname, "clk_uart_baud%d", cnt); + clk = clk_get(ourport->port.dev, clkname); + if (IS_ERR_OR_NULL(clk)) + continue; + + rate = clk_get_rate(clk); + if (!rate) + continue; + + if (ourport->info->has_divslot) { + unsigned long div = rate / req_baud; + + /* The UDIVSLOT register on the newer UARTs allows us to + * get a divisor adjustment of 1/16th on the baud clock. + * + * We don't keep the UDIVSLOT value (the 16ths we + * calculated by not multiplying the baud by 16) as it + * is easy enough to recalculate. + */ + + quot = div / 16; + baud = rate / div; + } else { + quot = (rate + (8 * req_baud)) / (16 * req_baud); + baud = rate / (quot * 16); } - } - - /* ok, we now need to select the best clock we found */ - - if (!best) { - unsigned int deviation = (1<<30)|((1<<30)-1); - int calc_deviation; + quot--; - for (sptr = res; sptr < resptr; sptr++) { - calc_deviation = baud - sptr->calc; - if (calc_deviation < 0) - calc_deviation = -calc_deviation; + calc_deviation = req_baud - baud; + if (calc_deviation < 0) + calc_deviation = -calc_deviation; - if (calc_deviation < deviation) { - best = sptr; - deviation = calc_deviation; - } + if (calc_deviation < deviation) { + *best_clk = clk; + best_quot = quot; + *clk_num = cnt; + deviation = calc_deviation; } } - /* store results to pass back */ - - *clksrc = best->clksrc; - *clk = best->src; - - return best->quot; + return best_quot; } /* udivslot_table[] @@ -717,10 +683,9 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, { struct s3c2410_uartcfg *cfg = s3c24xx_port_to_cfg(port); struct s3c24xx_uart_port *ourport = to_ourport(port); - struct s3c24xx_uart_clksrc *clksrc = NULL; struct clk *clk = NULL; unsigned long flags; - unsigned int baud, quot; + unsigned int baud, quot, clk_sel = 0; unsigned int ulcon; unsigned int umcon; unsigned int udivslot = 0; @@ -736,17 +701,16 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, */ baud = uart_get_baud_rate(port, termios, old, 0, 115200*8); - + quot = s3c24xx_serial_getclk(ourport, baud, &clk, &clk_sel); if (baud == 38400 && (port->flags & UPF_SPD_MASK) == UPF_SPD_CUST) quot = port->custom_divisor; - else - quot = s3c24xx_serial_getclk(port, &clksrc, &clk, baud); + if (!clk) + return; /* check to see if we need to change clock source */ - if (ourport->clksrc != clksrc || ourport->baudclk != clk) { - dbg("selecting clock %p\n", clk); - s3c24xx_serial_setsource(port, clksrc); + if (ourport->baudclk != clk) { + s3c24xx_serial_setsource(port, clk_sel); if (ourport->baudclk != NULL && !IS_ERR(ourport->baudclk)) { clk_disable(ourport->baudclk); @@ -755,7 +719,6 @@ static void s3c24xx_serial_set_termios(struct uart_port *port, clk_enable(clk); - ourport->clksrc = clksrc; ourport->baudclk = clk; ourport->baudclk_rate = clk ? clk_get_rate(clk) : 0; } @@ -1202,7 +1165,7 @@ static ssize_t s3c24xx_serial_show_clksrc(struct device *dev, struct uart_port *port = s3c24xx_dev_to_port(dev); struct s3c24xx_uart_port *ourport = to_ourport(port); - return snprintf(buf, PAGE_SIZE, "* %s\n", ourport->clksrc->name); + return snprintf(buf, PAGE_SIZE, "* %s\n", ourport->baudclk->name); } static DEVICE_ATTR(clock_source, S_IRUGO, s3c24xx_serial_show_clksrc, NULL); @@ -1382,12 +1345,13 @@ static void __init s3c24xx_serial_get_options(struct uart_port *port, int *baud, int *parity, int *bits) { - struct s3c24xx_uart_clksrc clksrc; struct clk *clk; unsigned int ulcon; unsigned int ucon; unsigned int ubrdiv; unsigned long rate; + unsigned int clk_sel; + char clk_name[MAX_CLK_NAME_LENGTH]; ulcon = rd_regl(port, S3C2410_ULCON); ucon = rd_regl(port, S3C2410_UCON); @@ -1432,11 +1396,12 @@ s3c24xx_serial_get_options(struct uart_port *port, int *baud, /* now calculate the baud rate */ - s3c24xx_serial_getsource(port, &clksrc); + clk_sel = s3c24xx_serial_getsource(port); + sprintf(clk_name, "clk_uart_baud%d", clk_sel); - clk = clk_get(port->dev, clksrc.name); + clk = clk_get(port->dev, clk_name); if (!IS_ERR(clk) && clk != NULL) - rate = clk_get_rate(clk) / clksrc.divisor; + rate = clk_get_rate(clk); else rate = 1; diff --git a/drivers/tty/serial/samsung.h b/drivers/tty/serial/samsung.h index 6c9cb9d..11369f3 100644 --- a/drivers/tty/serial/samsung.h +++ b/drivers/tty/serial/samsung.h @@ -19,6 +19,10 @@ struct s3c24xx_uart_info { unsigned long tx_fifomask; unsigned long tx_fifoshift; unsigned long tx_fifofull; + unsigned int def_clk_sel; + unsigned long num_clks; + unsigned long clksel_mask; + unsigned long clksel_shift; /* uart port features */