Messages in this thread | | | Date | Wed, 11 Nov 2020 10:41:57 +0000 | From | Sudeep Holla <> | Subject | Re: [PATCH v1 2/2] firmware: arm_scmi: Augment SMC/HVC to allow optional interrupt |
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On Tue, Nov 10, 2020 at 01:38:19PM -0500, Jim Quinlan wrote: > The SMC/HVC SCMI transport is modified to allow the completion of an SCMI > message to be indicated by an interrupt rather than the return of the smc > call. This accommodates the existing behavior of the BrcmSTB SCMI > "platform" whose SW is already out in the field and cannot be changed. > > Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com> > --- > drivers/firmware/arm_scmi/smc.c | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c > index 82a82a5dc86a..3bf935dbd00e 100644 > --- a/drivers/firmware/arm_scmi/smc.c > +++ b/drivers/firmware/arm_scmi/smc.c > @@ -9,9 +9,11 @@ > #include <linux/arm-smccc.h> > #include <linux/device.h> > #include <linux/err.h> > +#include <linux/interrupt.h> > #include <linux/mutex.h> > #include <linux/of.h> > #include <linux/of_address.h> > +#include <linux/of_irq.h> > #include <linux/slab.h> > > #include "common.h" > @@ -23,6 +25,8 @@ > * @shmem: Transmit/Receive shared memory area > * @shmem_lock: Lock to protect access to Tx/Rx shared memory area > * @func_id: smc/hvc call function id > + * @irq: Optional; employed when platforms indicates msg completion by intr. > + * @tx_complete: Optional, employed only when irq is valid. > */ > > struct scmi_smc { > @@ -30,8 +34,19 @@ struct scmi_smc { > struct scmi_shared_mem __iomem *shmem; > struct mutex shmem_lock; > u32 func_id; > + int irq; > + struct completion tx_complete; > }; > > +static irqreturn_t smc_msg_done_isr(int irq, void *data) > +{ > + struct scmi_smc *scmi_info = data; > + > + complete(&scmi_info->tx_complete); > + > + return IRQ_HANDLED; > +} > + > static bool smc_chan_available(struct device *dev, int idx) > { > struct device_node *np = of_parse_phandle(dev->of_node, "shmem", 0); > @@ -79,6 +94,20 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, > if (ret < 0) > return ret; > > + /* Optional feature -- signal message completion using an interrupt */ > + ret = of_irq_get_byname(cdev->of_node, "msg-serviced");
So, looks like it is mandatory if "interrupts" is used. Please update the binding or if that is not the practice followed elsewhere, drop search by name. Also I prefer full name "message-serviced" if possible, not strong opinion.
> + if (ret > 0) { > + scmi_info->irq = ret;
May be set this only if we succeed setting up handler ? I mean move this down.
Other than these, the changes look fine.
-- Regards, Sudeep
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