On Tue, Jan 03, 2023 at 04:15:31PM +0800, Haotien Hsu wrote:
> From: Sing-Han Chen <singhanc@xxxxxxxxxx>
>
> For the CCGx, when the OPM field in the INTR_REG is cleared, then the
> CCI data in the PPM is reset.
>
> To align with the CCGx UCSI interface guide, this patch updates the
> driver to copy CCI and MESSAGE_IN before clearing UCSI interrupt.
> When a new command is sent, the driver will clear the old CCI and
> MESSAGE_IN copy.
>
> Finally, clear UCSI_READ_INT before calling complete() to ensure that
> the ucsi_ccg_sync_write() would wait for the interrupt handling to
> complete.
> It prevents the driver from resetting CCI prematurely.
>
> Signed-off-by: Sing-Han Chen <singhanc@xxxxxxxxxx>
> Signed-off-by: Haotien Hsu <haotienh@xxxxxxxxxx>
> ---
> V1->V2
> - Fix uninitialized symbol 'cci'
> v2->v3
> - Remove wrong Reported-by tags
> ---
> drivers/usb/typec/ucsi/ucsi_ccg.c | 86 ++++++++++++++++++++++++++++---
> 1 file changed, 79 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/usb/typec/ucsi/ucsi_ccg.c b/drivers/usb/typec/ucsi/ucsi_ccg.c
> index eab3012e1b01..b35a3a97c9fb 100644
> --- a/drivers/usb/typec/ucsi/ucsi_ccg.c
> +++ b/drivers/usb/typec/ucsi/ucsi_ccg.c
> @@ -192,6 +192,12 @@ struct ucsi_ccg_altmode {
> bool checked;
> } __packed;
>
> +#define CCGX_MESSAGE_IN_MAX 4
> +struct op_region {
> + u32 cci;
> + u32 message_in[CCGX_MESSAGE_IN_MAX];
> +};
> +
> struct ucsi_ccg {
> struct device *dev;
> struct ucsi *ucsi;
> @@ -222,6 +228,9 @@ struct ucsi_ccg {
> bool has_multiple_dp;
> struct ucsi_ccg_altmode orig[UCSI_MAX_ALTMODES];
> struct ucsi_ccg_altmode updated[UCSI_MAX_ALTMODES];
> +
> + spinlock_t op_lock;
What does this lock protect? Please document that so that we can verify
if this really is a correct change _AND_ so we know what future changes
need to take the lock or not.
> + struct op_region op_data;
> };
>
> static int ccg_read(struct ucsi_ccg *uc, u16 rab, u8 *data, u32 len)
> @@ -305,12 +314,57 @@ static int ccg_write(struct ucsi_ccg *uc, u16 rab, const u8 *data, u32 len)
> return 0;
> }
>
> +static void ccg_op_region_read(struct ucsi_ccg *uc, unsigned int offset,
> + void *val, size_t val_len)
> +{
> + struct op_region *data = &uc->op_data;
> +
> + spin_lock(&uc->op_lock);
> + if (offset == UCSI_CCI)
> + memcpy(val, &data->cci, val_len);
> + else if (offset == UCSI_MESSAGE_IN)
> + memcpy(val, &data->message_in, val_len);
> + spin_unlock(&uc->op_lock);
> +}
> +
> +static void ccg_op_region_update(struct ucsi_ccg *uc, u32 cci)
> +{
> + u16 reg = CCGX_RAB_UCSI_DATA_BLOCK(UCSI_MESSAGE_IN);
> + struct op_region *data = &uc->op_data;
> + u32 message_in[CCGX_MESSAGE_IN_MAX];
> +
> + if (UCSI_CCI_LENGTH(cci))
> + if (ccg_read(uc, reg, (void *)&message_in,
> + sizeof(message_in))) {
> + dev_err(uc->dev, "failed to read MESSAGE_IN\n");
What can userspace do with this error? Will it be repeated a lot?
thanks,
greg k-h
