Hi Greg
> -----Original Message-----
> From: Greg KH <greg@xxxxxxxxx>
> Sent: Thursday, January 17, 2019 11:06 PM
> To: Ajay Gupta <ajayg@xxxxxxxxxx>
> Cc: heikki.krogerus@xxxxxxxxxxxxxxx; linux-usb@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH 1/7] usb: typec: ucsi: add get_fw_info function
>
> On Thu, Jan 17, 2019 at 05:09:03PM -0800, Ajay Gupta wrote:
> > Function is to get the details of ccg firmware and device version.
> >
> > Signed-off-by: Ajay Gupta <ajayg@xxxxxxxxxx>
> > ---
> > drivers/usb/typec/ucsi/ucsi_ccg.c | 76
> > ++++++++++++++++++++++++++++++-
> > 1 file changed, 74 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c
> > b/drivers/usb/typec/ucsi/ucsi_ccg.c
> > index de8a43bdff68..4d35279ab853 100644
> > --- a/drivers/usb/typec/ucsi/ucsi_ccg.c
> > +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
> > @@ -17,15 +17,46 @@
> > #include <asm/unaligned.h>
> > #include "ucsi.h"
> >
> > +struct ccg_dev_info {
> > + u8 fw_mode:2;
> > + u8 two_pd_ports:2;
> > + u8 row_size_256:2;
> > + u8:1; /* reserved */
> > + u8 hpi_v2_mode:1;
> > + u8 bl_mode:1;
> > + u8 cfgtbl_invalid:1;
> > + u8 fw1_invalid:1;
> > + u8 fw2_invalid:1;
> > + u8:4; /* reserved */
> > + u16 silicon_id;
> > + u16 bl_last_row;
> > +} __packed;
>
> Doesn't all of this break into tiny pieces when you read the memory into a big-
> endian system? Be very careful when using bitfields as a "raw"
> representation of a structure in memory.
I am planning to drop bit fields itself.
> > +
> > +struct version_format {
> > + u16 build;
> > + u8 patch;
> > + u8 min:4;
> > + u8 maj:4;
> > +};
>
> Same here.
>
> And not packed? That's dangerous :)
Same here.
>
>
> > +
> > +struct version_info {
> > + struct version_format base;
> > + struct version_format app;
> > +};
> > +
> > struct ucsi_ccg {
> > struct device *dev;
> > struct ucsi *ucsi;
> > struct ucsi_ppm ppm;
> > struct i2c_client *client;
> > + struct ccg_dev_info info;
> > };
> >
> > -#define CCGX_RAB_INTR_REG 0x06
> > -#define CCGX_RAB_UCSI_CONTROL 0x39
> > +#define CCGX_RAB_DEVICE_MODE 0x0000
> > +#define CCGX_RAB_INTR_REG 0x0006
> > +#define CCGX_RAB_READ_ALL_VER 0x0010
> > +#define CCGX_RAB_READ_FW2_VER 0x0020
> > +#define CCGX_RAB_UCSI_CONTROL 0x0039
> > #define CCGX_RAB_UCSI_CONTROL_START BIT(0)
> > #define CCGX_RAB_UCSI_CONTROL_STOP BIT(1)
> > #define CCGX_RAB_UCSI_DATA_BLOCK(offset) (0xf000 | ((offset) &
> 0xff))
> > @@ -220,6 +251,41 @@ static irqreturn_t ccg_irq_handler(int irq, void *data)
> > return IRQ_HANDLED;
> > }
> >
> > +static int get_fw_info(struct ucsi_ccg *uc) {
> > + struct device *dev = uc->dev;
> > + struct version_info version[3];
> > + struct version_info *v;
> > + int err, i;
> > +
> > + err = ccg_read(uc, CCGX_RAB_READ_ALL_VER, (u8 *)(&version),
> > + sizeof(version));
> > + if (err < 0)
> > + return err;
> > +
> > + for (i = 1; i < ARRAY_SIZE(version); i++) {
> > + v = &version[i];
> > + dev_dbg(dev,
> > + "FW%d Version: %c%c v%x.%x%x, [Base
> %d.%d.%d.%d]\n",
> > + i, (v->app.build >> 8), (v->app.build & 0xFF),
> > + v->app.patch, v->app.maj, v->app.min,
> > + v->base.maj, v->base.min, v->base.patch,
> > + v->base.build);
> > + }
> > +
> > + err = ccg_read(uc, CCGX_RAB_DEVICE_MODE, (u8 *)(&uc->info),
> > + sizeof(uc->info));
> > + if (err < 0)
> > + return err;
> > +
> > + dev_dbg(dev, "fw_mode: %d\n", uc->info.fw_mode);
> > + dev_dbg(dev, "fw1_invalid: %d\n", uc->info.fw1_invalid);
> > + dev_dbg(dev, "fw2_invalid: %d\n", uc->info.fw2_invalid);
> > + dev_dbg(dev, "silicon_id: 0x%04x\n", uc->info.silicon_id);
> > +
> > + return 0;
> > +}
> > +
> > static int ucsi_ccg_probe(struct i2c_client *client,
> > const struct i2c_device_id *id)
> > {
> > @@ -248,6 +314,12 @@ static int ucsi_ccg_probe(struct i2c_client *client,
> > return status;
> > }
> >
> > + status = get_fw_info(uc);
> > + if (status < 0) {
> > + dev_err(uc->dev, "get_fw_info failed - %d\n", status);
> > + return status;
>
> Are all devices required to have this information? if not, you just prevented
> them from working I think :(
The error is due to ccg_read() failure and in that case we want to stop.
Thanks
> nvpublic
> thanks,
>
> greg k-h
