Re: [early RFC] Device Tree bindings for OMAP3 Camera Subsystem

013/11/3 Sebastian Reichel [off-list ref]:

Hi,

This is an early RFC for omap3isp DT support. For now i just created a potential DT
binding documentation based on the existing platform data:

Binding for the OMAP3 Camera subsystem with the image signal processor (ISP) feature.

This is very interesting, I am in the process of transforming an (out
of tree) machine board file into
a device tree description, and I was precisely searching for "oma3isp
dt" when I saw your mail.
I would be happy to test or help develop any patch aiming at DT
support for omap3isp. I am new to DT, so I
will leave the DT bindings review to  people that actually  have a clue.

I am looking forward to testing patches and bugging you when things break ;)
Regards,
Jean-Philippe François

omap3isp node
-------------

Required properties:

- compatible    : should be "ti,omap3isp" for OMAP3;
- reg           : physical addresses and length of the registers set;
- clocks        : list of clock specifiers, corresponding to entries in
                  clock-names property;
- clock-names   : must contain "cam_ick", "cam_mclk", "csi2_96m_fck",
                  "l3_ick" entries, matching entries in the clocks property;
- interrupts    : must contain mmu interrupt;
- ti,iommu      : phandle to isp mmu;

Optional properties:

- VDD_CSIPHY1-supply    : regulator for csi phy1
- VDD_CSIPHY2-supply    : regulator for csi phy2
- ti,isp-xclk-1         : device(s) attached to ISP's first external clock
- ti,isp-xclk-2         : device(s) attached to ISP's second external clock

device-group subnode
--------------------

Required properties:
- ti,isp-interface-type : Integer describing the interface type, one of the following
   * 0 = ISP_INTERFACE_PARALLEL
   * 1 = ISP_INTERFACE_CSI2A_PHY2
   * 2 = ISP_INTERFACE_CCP2B_PHY1
   * 3 = ISP_INTERFACE_CCP2B_PHY2
   * 4 = ISP_INTERFACE_CSI2C_PHY1
- ti,isp-devices        : Array of phandles to devices connected via the interface
- One of the following configuration nodes (depending on ti,isp-interface-type)
 - ti,ccp2-bus-cfg      : CCP2 bus configuration (needed for ISP_INTERFACE_CCP*)
 - ti,parallel-bus-cfg  : PARALLEL bus configuration (needed for ISP_INTERFACE_PARALLEL)
 - ti,csi2-bus-cfg      : CSI bus configuration (needed for ISP_INTERFACE_CSI*)

ccp2-bus-cfg subnode
--------------------

Required properties:
- ti,video-port-clock-divisor   : integer; used for video port output clock control

Optional properties:
- ti,inverted-clock             : boolean; clock/strobe signal is inverted
- ti,enable-crc                 : boolean; enable crc checking
- ti,ccp2-mode-mipi             : boolean; port is used in MIPI-CSI1 mode (default: CCP2 mode)
- ti,phy-layer-is-strobe        : boolean; use data/strobe physical layer (default: data/clock physical layer)
- ti,data-lane-configuration    : integer array with position and polarity information for lane 1 and 2
- ti,clock-lane-configuration   : integer array with position and polarity information for clock lane

parallel-bus-cfg subnode
------------------------

Required properties:
- ti,data-lane-shift                            : integer; shift data lanes by this amount

Optional properties:
- ti,clock-falling-edge                         : boolean; sample on falling edge (default: rising edge)
- ti,horizontal-synchronization-active-low      : boolean; default: active high
- ti,vertical-synchronization-active-low        : boolean; default: active high
- ti,data-polarity-ones-complement              : boolean; data polarity is one's complement

csi2-bus-cfg subnode
--------------------

Required properties:
- ti,video-port-clock-divisor   : integer; used for video port output clock control

Optional properties:
- ti,data-lane-configuration    : integer array with position and polarity information for lane 1 and 2
- ti,clock-lane-configuration   : integer array with position and polarity information for clock lane
- ti,enable-crc                 : boolean; enable crc checking

Example for Nokia N900
----------------------

omap3isp: isp@480BC000 {
        compatible = "ti,omap3isp";
        reg = <
                /* OMAP3430+ */
                0x480BC000 0x070        /* base */
                0x480BC100 0x078        /* cbuf */
                0x480BC400 0x1F0        /* cpp2 */
                0x480BC600 0x0A8        /* ccdc */
                0x480BCA00 0x048        /* hist */
                0x480BCC00 0x060        /* h3a  */
                0x480BCE00 0x0A0        /* prev */
                0x480BD000 0x0AC        /* resz */
                0x480BD200 0x0FC        /* sbl  */
                0x480BD400 0x070        /* mmu  */
        >;

        clocks = < &cam_ick &cam_mclk &csi2_96m_fck &l3_ick >;
        clock-names = "cam_ick", "cam_mclk", "csi2_96m_fck", "l3_ick";

        interrupts = <24>;

        ti,iommu = <&mmu_isp>;

        ti,isp-xclk-1 = <
                &et8ek8
                &smiapp_dfl
        >;

        group1: device-group@0 {
                ti,isp-interface-type = <2>;

                ti,isp-devices = <
                        &et8ek8
                        &ad5820
                        &adp1653
                >;

                ti,ccp2-bus-cfg {
                        ti,enable-crc;
                        ti,phy-layer-is-strobe;
                        ti,video-port-clock-divisor = <1>;
                };
        };

        group2: device-group@1 {
                ti,isp-interface-type = <2>;

                ti,isp-devices = <
                        &smiapp_dfl
                >;

                ti,ccp2-bus-cfg {
                        ti,enable-crc;
                        ti,phy-layer-is-strobe;
                        ti,video-port-clock-divisor = <1>;
                };
        };
};