From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marek Vasut Subject: [PATCH 1/2] MXS: Set I2C timing registers for mxs-i2c Date: Sun, 27 May 2012 04:10:55 +0200 Message-ID: <1338084656-11961-1-git-send-email-marex@denx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Cc: Marek Vasut , Detlev Zundel , Dong Aisheng , Fabio Estevam , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sascha Hauer , Shawn Guo , Stefano Babic , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Wolfgang Denk , Wolfram Sang List-Id: linux-i2c@vger.kernel.org This patch configures the I2C bus timing registers according to information passed via DT. Currently, 100kHz and 400kHz modes are supported. Signed-off-by: Marek Vasut Cc: Detlev Zundel CC: Dong Aisheng CC: Fabio Estevam Cc: Linux ARM kernel Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org CC: Sascha Hauer CC: Shawn Guo Cc: Stefano Babic CC: Uwe Kleine-K=C3=B6nig Cc: Wolfgang Denk Cc: Wolfram Sang --- Documentation/devicetree/bindings/i2c/i2c-mxs.txt | 1 + arch/arm/boot/dts/imx28.dtsi | 2 + drivers/i2c/busses/i2c-mxs.c | 64 +++++++++++++= ++++++++ 3 files changed, 67 insertions(+) diff --git a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt b/Docume= ntation/devicetree/bindings/i2c/i2c-mxs.txt index 1bfc02d..790b5c6 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-mxs.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-mxs.txt @@ -4,6 +4,7 @@ Required properties: - compatible: Should be "fsl,-i2c" - reg: Should contain registers location and length - interrupts: Should contain ERROR and DMA interrupts +- speed: Speed of the bus in kHz (400 or 100 are supported) =20 Examples: =20 diff --git a/arch/arm/boot/dts/imx28.dtsi b/arch/arm/boot/dts/imx28.dts= i index 4634cb8..d927155 100644 --- a/arch/arm/boot/dts/imx28.dtsi +++ b/arch/arm/boot/dts/imx28.dtsi @@ -381,6 +381,7 @@ compatible =3D "fsl,imx28-i2c"; reg =3D <0x80058000 2000>; interrupts =3D <111 68>; + fsl,speed =3D <400>; status =3D "disabled"; }; =20 @@ -390,6 +391,7 @@ compatible =3D "fsl,imx28-i2c"; reg =3D <0x8005a000 2000>; interrupts =3D <110 69>; + fsl,speed =3D <400>; status =3D "disabled"; }; =20 diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.= c index 04eb441..fff0a09 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -46,6 +46,10 @@ #define MXS_I2C_CTRL0_DIRECTION 0x00010000 #define MXS_I2C_CTRL0_XFER_COUNT(v) ((v) & 0x0000FFFF) =20 +#define MXS_I2C_TIMING0 (0x10) +#define MXS_I2C_TIMING1 (0x20) +#define MXS_I2C_TIMING2 (0x30) + #define MXS_I2C_CTRL1 (0x40) #define MXS_I2C_CTRL1_SET (0x44) #define MXS_I2C_CTRL1_CLR (0x48) @@ -97,6 +101,24 @@ #define MXS_CMD_I2C_READ (MXS_I2C_CTRL0_SEND_NAK_ON_LAST | \ MXS_I2C_CTRL0_MASTER_MODE) =20 +struct mxs_i2c_speed_config { + uint32_t timing0; + uint32_t timing1; + uint32_t timing2; +}; + +const struct mxs_i2c_speed_config mxs_i2c_95kHz_config =3D { + .timing0 =3D 0x00780030, + .timing1 =3D 0x00800030, + .timing2 =3D 0x0015000d, +}; + +const struct mxs_i2c_speed_config mxs_i2c_400kHz_config =3D { + .timing0 =3D 0x000f0007, + .timing1 =3D 0x001f000f, + .timing2 =3D 0x0015000d, +}; + /** * struct mxs_i2c_dev - per device, private MXS-I2C data * @@ -112,11 +134,17 @@ struct mxs_i2c_dev { struct completion cmd_complete; u32 cmd_err; struct i2c_adapter adapter; + const struct mxs_i2c_speed_config *speed; }; =20 static void mxs_i2c_reset(struct mxs_i2c_dev *i2c) { stmp_reset_block(i2c->regs); + + writel(i2c->speed->timing0, i2c->regs + MXS_I2C_TIMING0); + writel(i2c->speed->timing1, i2c->regs + MXS_I2C_TIMING1); + writel(i2c->speed->timing2, i2c->regs + MXS_I2C_TIMING2); + writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET); writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE, i2c->regs + MXS_I2C_QUEUECTRL_SET); @@ -319,6 +347,38 @@ static const struct i2c_algorithm mxs_i2c_algo =3D= { .functionality =3D mxs_i2c_func, }; =20 +#ifdef CONFIG_OF +static int mxs_i2c_get_ofdata(struct platform_device *pdev, + struct mxs_i2c_dev *i2c) +{ + const __be32 *speed; + uint32_t speed_khz; + struct device_node *node =3D pdev->dev.of_node; + + if (!node) + return -EINVAL; + + i2c->speed =3D &mxs_i2c_95kHz_config; + speed =3D of_get_property(node, "fsl,speed", NULL); + if (!speed) + dev_warn(&pdev->dev, + "No I2C speed selected, using 100kHz\n"); + + speed_khz =3D be32_to_cpup(speed); + if (speed_khz =3D=3D 400) + i2c->speed =3D &mxs_i2c_400kHz_config; + else if (speed_khz !=3D 100) + dev_warn(&pdev->dev, + "Invalid I2C speed selected, using 100kHz\n"); + + return 0; +} +#else +static int mxs_i2c_get_ofdata(struct platform_device *pdev, + struct mxs_i2c_dev *i2c) +{ } +#endif /* CONFIG_OF */ + static int __devinit mxs_i2c_probe(struct platform_device *pdev) { struct device *dev =3D &pdev->dev; @@ -357,6 +417,10 @@ static int __devinit mxs_i2c_probe(struct platform= _device *pdev) if (err) return err; =20 + err =3D mxs_i2c_get_ofdata(pdev, i2c); + if (err) + return err; + i2c->dev =3D dev; platform_set_drvdata(pdev, i2c); =20 --=20 1.7.10