From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934006Ab3LIQbX (ORCPT ); Mon, 9 Dec 2013 11:31:23 -0500 Received: from mailout1.w1.samsung.com ([210.118.77.11]:29831 "EHLO mailout1.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932737Ab3LIQbT (ORCPT ); Mon, 9 Dec 2013 11:31:19 -0500 X-AuditID: cbfec7f4-b7f966d0000003d9-48-52a5f055dab4 From: Tomasz Figa To: Naveen Krishna Chatradhi Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-samsung-soc@vger.kernel.org, hs@denx.de, khali@linux-fr.org, ben-linux@fluff.org, naveenkrishna.ch@gmail.com Subject: Re: [PATCH 2/2] i2c: exynos5: configure fifo_depth based on HSI2C module version Date: Mon, 09 Dec 2013 17:31:07 +0100 Message-id: <1739891.MYO4PRtJOt@amdc1227> Organization: Samsung Poland R&D Center User-Agent: KMail/4.11.3 (Linux/3.11.5-gentoo; KDE/4.11.3; x86_64; ; ) In-reply-to: <1385100851-32254-1-git-send-email-ch.naveen@samsung.com> References: <1385100851-32254-1-git-send-email-ch.naveen@samsung.com> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset=us-ascii X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrMLMWRmVeSWpSXmKPExsVy+t/xa7qhH5YGGexbY2wxad0BJou7zw8z Wuy4c5/ZovFvpEXH3y+MFpd3zWGzmHF+H5PFom3/mR04PObNOsHi8XfVC2aPnbPusntcaTjJ 5tG3ZRWjx+dNcgFsUVw2Kak5mWWpRfp2CVwZs7euZS34LFLxd8MaxgbG1wJdjJwcEgImEk8a VjNB2GISF+6tZ+ti5OIQEljKKPH1xD4op4tJ4siGG6wgVWwCahKfGx6xgdgiQN3HX51hByli FtjMKHHx82wWkISwQLTE1j07wYpYBFQljvf3gsV5BTQllq8+AWbzC6hLvNv2FGy1qICbxIt9 W9hBbE4g+9+TiUBxDqDNrhLXJ0ZCtApK/Jh8D6yVWUBeYt/+qawQtpbE+p3HmSYwCs5CUjYL SdksJGULGJlXMYqmliYXFCel5xrqFSfmFpfmpesl5+duYoRExJcdjIuPWR1iFOBgVOLhXcG6 NEiINbGsuDL3EKMEB7OSCG/Da6AQb0piZVVqUX58UWlOavEhRiYOTqkGxvUa3HGSpRYfZnW8 fH44X9i0u2y11D21KyW7J5iXlQhcfvxcfI7NtnV+L/lvBLec5li1w1yebWfg0bUTfvQtKVmk vLNX0Nin8QhneMiJFZtO973Zyrle5cCzLVHdznVdsveO2THy7JuZ5vbuZAjnasfKB352v5kX u/QxPd3xgnNfev27d/cfn1NiKc5INNRiLipOBACac+VIZgIAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Naveen, On Friday 22 of November 2013 11:44:11 Naveen Krishna Chatradhi wrote: > fifo_depth of the HSI2C is not constant > Exynos5420 and Exynos5250 supports fifo_depth of 64bytes > Exynos5260 supports fifo_depth of 16bytes > > This patch configures the fifo_depth based on HSI2C modules version. > Signed-off-by: Naveen Krishna Chatradhi > --- > drivers/i2c/busses/i2c-exynos5.c | 29 ++++++++++++++++++----------- > 1 file changed, 18 insertions(+), 11 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-exynos5.c b/drivers/i2c/busses/i2c-exynos5.c > index cbb49e2..19277d8 100644 > --- a/drivers/i2c/busses/i2c-exynos5.c > +++ b/drivers/i2c/busses/i2c-exynos5.c > @@ -77,12 +77,6 @@ > #define HSI2C_RXFIFO_TRIGGER_LEVEL(x) ((x) << 4) > #define HSI2C_TXFIFO_TRIGGER_LEVEL(x) ((x) << 16) > > -/* As per user manual FIFO max depth is 64bytes */ > -#define HSI2C_FIFO_MAX 0x40 > -/* default trigger levels for Tx and Rx FIFOs */ > -#define HSI2C_DEF_TXFIFO_LVL (HSI2C_FIFO_MAX - 0x30) > -#define HSI2C_DEF_RXFIFO_LVL (HSI2C_FIFO_MAX - 0x10) > - > /* I2C_TRAILING_CTL Register bits */ > #define HSI2C_TRAILING_COUNT (0xf) > > @@ -187,6 +181,9 @@ struct exynos5_i2c { > > /* Version of HS-I2C Hardware */ > unsigned int version; > + > + /* FIFO depth */ > + unsigned int fifo_depth; > }; > > enum hsi2c_version { > @@ -437,7 +434,7 @@ static irqreturn_t exynos5_i2c_irq(int irqno, void *dev_id) > fifo_status = readl(i2c->regs + HSI2C_FIFO_STATUS); > fifo_level = HSI2C_TX_FIFO_LVL(fifo_status); > > - len = HSI2C_FIFO_MAX - fifo_level; > + len = i2c->fifo_depth - fifo_level; > if (len > (i2c->msg->len - i2c->msg_ptr)) > len = i2c->msg->len - i2c->msg_ptr; > > @@ -505,6 +502,7 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop) > u32 i2c_auto_conf = 0; > u32 fifo_ctl; > unsigned long flags; > + unsigned short trig_lvl; > > i2c_ctl = readl(i2c->regs + HSI2C_CTL); > i2c_ctl &= ~(HSI2C_TXCHON | HSI2C_RXCHON); > @@ -515,13 +513,19 @@ static void exynos5_i2c_message_start(struct exynos5_i2c *i2c, int stop) > > i2c_auto_conf = HSI2C_READ_WRITE; > > - fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(HSI2C_DEF_TXFIFO_LVL); > + trig_lvl = (i2c->msg->len > i2c->fifo_depth) ? > + (i2c->fifo_depth * 3/4) : i2c->msg->len; This patch changes the fifo trigger level calculation (it's dependent now on message length), not just maximum fifo size, as the description says. It should be split into two separate patches, explaining why both changes are necessary. Best regards, Tomasz