Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423600Ab3FUSWM (ORCPT ); Fri, 21 Jun 2013 14:22:12 -0400 Received: from mail1b.islandnet.com ([199.175.107.121]:36509 "EHLO mail1.islandnet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1423383Ab3FUSWL (ORCPT ); Fri, 21 Jun 2013 14:22:11 -0400 X-Greylist: delayed 484 seconds by postgrey-1.27 at vger.kernel.org; Fri, 21 Jun 2013 14:22:11 EDT Message-ID: <51C497EF.1070108@acumalabs.com> Date: Fri, 21 Jun 2013 11:14:07 -0700 From: Simon Pearson User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130509 Thunderbird/17.0.6 MIME-Version: 1.0 To: grant.likely@secretlab.ca, linus.walleij@linaro.org CC: shawn.guo@linaro.org, linux-kernel@vger.kernel.org Subject: [PATCH 001/001] gpio-mxs: Select faster gpio-generic set methods Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1285 Lines: 29 From: Simon Pearson Kernel 3.8.4. By defining both the set and clear registers, the speed of the gpio isimproved. gpio-generic.c, selects the bgpio_set_with_clear() which isfaster than the current bgpio_set_set(). This has performance implications for all bitbang drivers (i2c, spi, etc). Slow SPI as compared to 2.6.35.33 improved by a factor of 10 (80kHz CLK to 800kHz CLK). Signed-off-by: Simon Pearson --- --- a/drivers/gpio/gpio-mxs.c.orig 2013-03-20 13:11:19.000000000 -0700 +++ b/drivers/gpio/gpio-mxs.c 2013-06-21 10:02:33.000000000 -0700 @@ -292,7 +292,8 @@ static int mxs_gpio_probe(struct platfor err = bgpio_init(&port->bgc, &pdev->dev, 4, port->base + PINCTRL_DIN(port), - port->base + PINCTRL_DOUT(port), NULL, + port->base + PINCTRL_DOUT(port) + MXS_SET, + port->base + PINCTRL_DOUT(port) + MXS_CLR, port->base + PINCTRL_DOE(port), NULL, 0); if (err) goto out_irqdesc_free; -- 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/