From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Figa Subject: Re: [PATCH 1/2 v3] i2c: exynos5: add support for HSI2C on Exynos5260 SoC Date: Thu, 06 Feb 2014 14:31:16 +0100 Message-ID: <52F38EA4.10805@samsung.com> References: <1385100851-32254-1-git-send-email-ch.naveen@samsung.com> <1391688408-8077-1-git-send-email-ch.naveen@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1391688408-8077-1-git-send-email-ch.naveen@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org To: Naveen Krishna Chatradhi , linux-samsung-soc@vger.kernel.org, linux-i2c@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, devicetree-discuss@lists.ozlabs.org, naveenkrishna.ch@gmail.com, kgene.kim@samsung.com, grant.likely@secretlab.ca, w.sang@pengutronix.de, linux-kernel@vger.kernel.org, taeggyun.ko@samsung.com, balbi@ti.com, cpgs@samsung.com List-Id: linux-i2c@vger.kernel.org Hi Naveen, On 06.02.2014 13:06, Naveen Krishna Chatradhi wrote: > This patch implements a variant struct to handle the differences > (like fifo_depths) in the HSI2C modules across SoCs. > > Adds a new compatible to support HSI2C module on Exynos5260. > Also resets the module as an init sequence (Needed by Exynos5260). > > Signed-off-by: Naveen Krishna Chatradhi > --- > Changes since v2: > 1. Used variant struct as suggested by Tomasz Figa. > 2. Change compatible strings from samsung,exynos5-hsi2c to > samsung,exynos5250-hsi2c based on the first SoC to see the feature. > 3. Using reset as init sequences. > 4. Merged the 2 patches into one. > > .../devicetree/bindings/i2c/i2c-exynos5.txt | 8 ++- > drivers/i2c/busses/i2c-exynos5.c | 64 ++++++++++++++++---- > 2 files changed, 58 insertions(+), 14 deletions(-) > > diff --git a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt > index 056732c..5bc4998 100644 > --- a/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt > +++ b/Documentation/devicetree/bindings/i2c/i2c-exynos5.txt > @@ -5,7 +5,11 @@ at various speeds ranging from 100khz to 3.4Mhz. > > Required properties: > - compatible: value should be. > - -> "samsung,exynos5-hsi2c", for i2c compatible with exynos5 hsi2c. Device tree bindings need to be backwards compatible, so you need to keep this compatible string supported, just marked as (DEPRECATED). Driver-wise, it will use the same driver data / variant struct as "samsung,exynos5250-hsi2c", just one more entry in OF match table is needed. > + -> "samsung,exynos5250-hsi2c", for i2c compatible with HSI2C available > + on Exynos5250 and Exynos5420 SoCs. > + -> "samsung,exynos5260-hsi2c", for i2c compatible with HSI2C available > + on Exynos5260 SoCs. > + > - reg: physical base address of the controller and length of memory mapped > region. > - interrupts: interrupt number to the cpu. > @@ -26,7 +30,7 @@ Optional properties: > Example: > > hsi2c@12ca0000 { > - compatible = "samsung,exynos5-hsi2c"; > + compatible = "samsung,exynos5250-hsi2c"; > reg = <0x12ca0000 0x100>; > interrupts = <56>; > clock-frequency = <100000>; [snip] > @@ -483,6 +514,7 @@ 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); > @@ -493,13 +525,19 @@ 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->variant->fifo_depth) ? > + (i2c->variant->fifo_depth * 3/4) : i2c->msg->len; > + fifo_ctl |= HSI2C_RXFIFO_TRIGGER_LEVEL(trig_lvl); > + This is a rather serious semantic change, that doesn't look to belong to this patch. If this is needed, it should be done in a separate patch. > int_en |= (HSI2C_INT_RX_ALMOSTFULL_EN | > HSI2C_INT_TRAILING_EN); > } else { > i2c_ctl |= HSI2C_TXCHON; > > - fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(HSI2C_DEF_RXFIFO_LVL); > + trig_lvl = (i2c->msg->len > i2c->variant->fifo_depth) ? > + (i2c->variant->fifo_depth * 1/4) : i2c->msg->len; > + fifo_ctl |= HSI2C_TXFIFO_TRIGGER_LEVEL(trig_lvl); > + Ditto. Best regards, Tomasz