Messages in this thread | | | From | Vitor Soares <> | Subject | RE: [RFC 5/5] i3c: add i3cdev module to expose i3c dev in /dev | Date | Tue, 10 Dec 2019 19:15:05 +0000 |
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Hi Arnd,
From: Arnd Bergmann <arnd@arndb.de> Date: Tue, Dec 10, 2019 at 17:51:14
> On Tue, Dec 10, 2019 at 4:37 PM Vitor Soares <Vitor.Soares@synopsys.com> wrote: > > > > +/* IOCTL commands */ > > +#define I3C_DEV_IOC_MAGIC 0x07 > > + > > +struct i3c_ioc_priv_xfer { > > + struct i3c_priv_xfer __user *xfers; /* pointers to i3c_priv_xfer */ > > + __u32 nxfers; /* number of i3c_priv_xfer */ > > +}; > > + > > +#define I3C_IOC_PRIV_XFER \ > > + _IOW(I3C_DEV_IOC_MAGIC, 30, struct i3c_ioc_priv_xfer) > > + > > +#define I3C_IOC_PRIV_XFER_MAX_MSGS 42 > > This is not a great data structure for UAPI, please see > https://urldefense.proofpoint.com/v2/url?u=https-3A__git.kernel.org_pub_scm_linux_kernel_git_arnd_playground.git_tree_Documentation_core-2Dapi_ioctl.rst-3Fh-3Dcompat-2Dioctl-2Dendgame-26id-3D927324b7900ee9b877691a8b237e272fabb21bf5&d=DwIBaQ&c=DPL6_X_6JkXFx7AXWqB0tg&r=qVuU64u9x77Y0Kd0PhDK_lpxFgg6PK9PateHwjb_DY0&m=5Q9WjK0o93NR7DQ9NM6So6mfdgpNnZnSaP8qMpgaC7E&s=LzzjrUQAG8fx5jkVyK73dBDrahNAvk09Cxxlx3KOiXI&e= > > for some background. I'm planning to submit that documentation for > mainline integration soon. > > Arnd
Thanks for sharing the document.
My understanding is that I should use a data structure like the struct spi_ioc_transfer, with this I may also use the same ioctl command definition. Am I right? In the documentation you also refer the compact_ioctl() and It is not clear to me if the compact_ioctl() is mandatory in this case. Should I implement it as well?
Best regards, Vitor Soares
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