Re: [PATCH 2/4] ARM: shmobile: r8a7790: add I2C support in Device Tree mode

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

Hi Laurent

On Wed, 25 Sep 2013, Laurent Pinchart wrote:

> Hi Guennadi,
> 
> Thank you for the patch.
> 
> On Monday 09 September 2013 18:03:54 Guennadi Liakhovetski wrote:
> > This patch adds clocks and clock lookup entries for the four I2C
> > controllers on r8a7790 and respective Device Tree nodes.
> > 
> > Signed-off-by: Guennadi Liakhovetski <g.liakhovetski+renesas@gmail.com>
> > ---
> >  arch/arm/boot/dts/r8a7790.dtsi         |   36 +++++++++++++++++++++++++++++
> >  arch/arm/mach-shmobile/clock-r8a7790.c |   10 ++++++++
> >  2 files changed, 46 insertions(+), 0 deletions(-)
> > 
> > diff --git a/arch/arm/boot/dts/r8a7790.dtsi b/arch/arm/boot/dts/r8a7790.dtsi
> > index 885f9f4..a5021112 100644
> > --- a/arch/arm/boot/dts/r8a7790.dtsi
> > +++ b/arch/arm/boot/dts/r8a7790.dtsi
> > @@ -127,6 +127,42 @@
> >  		interrupts = <0 0 4>, <0 1 4>, <0 2 4>,	<0 3 4>;
> >  	};
> > 
> > +	i2c0: i2c@e6508000 {
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +		compatible = "renesas,i2c-rcar-h2";
> > +		reg = <0 0xe6508000 0 0x40>;
> > +		interrupt-parent = <&gic>;
> > +		interrupts = <0 287 0x4>;
> 
> Shouldn't you add state = "disabled" to all I2C controllers in order not to 
> enable the unused controllers by default ?

It would be logical, yes, and I seem to remember having discussed this 
earlier with someone (with Magnus, IIRC), and the outcome was, that all 
Renesas .dtsi files so far define all I2C directly in enabled mode and 
that it's intentional, so, I just followed this pattern here. You can 
indeed check in other .dtsi files - all seem to do exactly the same.

Thanks
Guennadi

> 
> > +	};
> > +
> > +	i2c1: i2c@e6518000 {
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +		compatible = "renesas,i2c-rcar-h2";
> > +		reg = <0 0xe6518000 0 0x40>;
> > +		interrupt-parent = <&gic>;
> > +		interrupts = <0 288 0x4>;
> > +	};
> > +
> > +	i2c2: i2c@e6530000 {
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +		compatible = "renesas,i2c-rcar-h2";
> > +		reg = <0 0xe6530000 0 0x40>;
> > +		interrupt-parent = <&gic>;
> > +		interrupts = <0 286 0x4>;
> > +	};
> > +
> > +	i2c3: i2c@e6540000 {
> > +		#address-cells = <1>;
> > +		#size-cells = <0>;
> > +		compatible = "renesas,i2c-rcar-h2";
> > +		reg = <0 0xe6540000 0 0x40>;
> > +		interrupt-parent = <&gic>;
> > +		interrupts = <0 290 0x4>;
> > +	};
> > +
> >  	mmcif0: mmcif@ee200000 {
> >  		compatible = "renesas,sh-mmcif";
> >  		reg = <0 0xee200000 0 0x80>;
> > diff --git a/arch/arm/mach-shmobile/clock-r8a7790.c
> > b/arch/arm/mach-shmobile/clock-r8a7790.c index fc36d3d..8e5e90b 100644
> > --- a/arch/arm/mach-shmobile/clock-r8a7790.c
> > +++ b/arch/arm/mach-shmobile/clock-r8a7790.c
> > @@ -52,6 +52,7 @@
> >  #define SMSTPCR5 0xe6150144
> >  #define SMSTPCR7 0xe615014c
> >  #define SMSTPCR8 0xe6150990
> > +#define SMSTPCR9 0xe6150994
> > 
> >  #define SDCKCR		0xE6150074
> >  #define SD2CKCR		0xE6150078
> > @@ -181,6 +182,7 @@ static struct clk div6_clks[DIV6_NR] = {
> > 
> >  /* MSTP */
> >  enum {
> > +	MSTP931, MSTP930, MSTP929, MSTP928,
> >  	MSTP813,
> >  	MSTP721, MSTP720,
> >  	MSTP717, MSTP716,
> > @@ -192,6 +194,10 @@ enum {
> >  };
> > 
> >  static struct clk mstp_clks[MSTP_NR] = {
> > +	[MSTP931] = SH_CLK_MSTP32(&hp_clk, SMSTPCR9, 31, 0), /* I2C0 */
> > +	[MSTP930] = SH_CLK_MSTP32(&hp_clk, SMSTPCR9, 30, 0), /* I2C1 */
> > +	[MSTP929] = SH_CLK_MSTP32(&hp_clk, SMSTPCR9, 29, 0), /* I2C2 */
> > +	[MSTP928] = SH_CLK_MSTP32(&hp_clk, SMSTPCR9, 28, 0), /* I2C3 */
> >  	[MSTP813] = SH_CLK_MSTP32(&p_clk, SMSTPCR8, 13, 0), /* Ether */
> >  	[MSTP721] = SH_CLK_MSTP32(&p_clk, SMSTPCR7, 21, 0), /* SCIF0 */
> >  	[MSTP720] = SH_CLK_MSTP32(&p_clk, SMSTPCR7, 20, 0), /* SCIF1 */
> > @@ -261,6 +267,10 @@ static struct clk_lookup lookups[] = {
> >  	CLKDEV_DEV_ID("sh-sci.7", &mstp_clks[MSTP720]),
> >  	CLKDEV_DEV_ID("sh-sci.8", &mstp_clks[MSTP717]),
> >  	CLKDEV_DEV_ID("sh-sci.9", &mstp_clks[MSTP716]),
> > +	CLKDEV_DEV_ID("e6508000.i2c", &mstp_clks[MSTP931]),
> > +	CLKDEV_DEV_ID("e6518000.i2c", &mstp_clks[MSTP930]),
> > +	CLKDEV_DEV_ID("e6530000.i2c", &mstp_clks[MSTP929]),
> > +	CLKDEV_DEV_ID("e6540000.i2c", &mstp_clks[MSTP928]),
> >  	CLKDEV_DEV_ID("r8a7790-ether", &mstp_clks[MSTP813]),
> >  	CLKDEV_DEV_ID("rcar_thermal", &mstp_clks[MSTP522]),
> >  	CLKDEV_DEV_ID("ee200000.mmcif", &mstp_clks[MSTP315]),
> -- 
> Regards,
> 
> Laurent Pinchart
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/