RE: [PATCH V5 2/4] firmware: imx: enable imx scu general irq function
From: Anson Huang
Date: Mon Apr 08 2019 - 09:05:49 EST
Hi, Aisheng
Best Regards!
Anson Huang
> -----Original Message-----
> From: Aisheng Dong
> Sent: 2019年4月8日 18:35
> To: Anson Huang <anson.huang@xxxxxxx>; robh+dt@xxxxxxxxxx;
> mark.rutland@xxxxxxx; shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx;
> kernel@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; a.zummo@xxxxxxxxxxxx;
> alexandre.belloni@xxxxxxxxxxx; ulf.hansson@xxxxxxxxxx; Daniel Baluta
> <daniel.baluta@xxxxxxx>; devicetree@xxxxxxxxxxxxxxx; linux-
> kernel@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-
> rtc@xxxxxxxxxxxxxxx
> Cc: dl-linux-imx <linux-imx@xxxxxxx>
> Subject: RE: [PATCH V5 2/4] firmware: imx: enable imx scu general irq
> function
>
> > From: Anson Huang
> > Sent: Monday, March 18, 2019 11:10 AM
> >
> > The System Controller Firmware (SCFW) controls RTC, thermal and WDOG
> > etc., these resources' interrupt function are managed by SCU. When any
> > IRQ pending, SCU will notify Linux via MU general interrupt channel
> > #3, and Linux kernel needs to call SCU APIs to get IRQ status and
> > notify each module to handle the interrupt.
> >
> > Since there is no data transmission for SCU IRQ notification, so
> > doorbell mode is used for this MU channel, and SCU driver will use
> > notifier mechanism to broadcast to every module which registers the SCU
> block notifier.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
>
> This patch mostly looks good me, except a few minor comments.
> Otherwise, you can add my tag.
>
> Reviewed-by: Dong Aisheng <aisheng.dong@xxxxxxx>
>
> > ---
> > Changes since V4:
> > - move scu irq support to a new file imx-scu-irq.c;
> > - improve the function name with "imx_scu_irq_" as prefix for irq
> > related functions;
> > - move MU IRQ sources id out of sc ipc struct;
> > - add IRQ group info message print when get irq status fail;
> > - move MU ID parse into imx_scu_enable_general_irq_channel()
> function
> > and ONLY do it
> > when irq channel enable successfully.
> > - change max IRQ group supported to 4, ONLY support for those
> kernel
> > features.
> > ---
> > drivers/firmware/imx/Makefile | 2 +-
> > drivers/firmware/imx/imx-scu-irq.c | 133
> > +++++++++++++++++++++++++++++++++++++
> > drivers/firmware/imx/imx-scu.c | 6 ++
> > include/linux/firmware/imx/sci.h | 4 ++
> > 4 files changed, 144 insertions(+), 1 deletion(-) create mode 100644
> > drivers/firmware/imx/imx-scu-irq.c
> >
> > diff --git a/drivers/firmware/imx/Makefile
> > b/drivers/firmware/imx/Makefile index 1b2e15b..802c4ad 100644
> > --- a/drivers/firmware/imx/Makefile
> > +++ b/drivers/firmware/imx/Makefile
> > @@ -1,3 +1,3 @@
> > # SPDX-License-Identifier: GPL-2.0
> > -obj-$(CONFIG_IMX_SCU) += imx-scu.o misc.o
> > +obj-$(CONFIG_IMX_SCU) += imx-scu.o misc.o imx-scu-irq.o
> > obj-$(CONFIG_IMX_SCU_PD) += scu-pd.o
> > diff --git a/drivers/firmware/imx/imx-scu-irq.c
> > b/drivers/firmware/imx/imx-scu-irq.c
> > new file mode 100644
> > index 0000000..0e20aa7
> > --- /dev/null
> > +++ b/drivers/firmware/imx/imx-scu-irq.c
> > @@ -0,0 +1,133 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright 2019 NXP
> > + *
> > + * Implementation of the SCU IRQ functions using MU.
> > + *
> > + */
> > +
> > +#include <dt-bindings/firmware/imx/rsrc.h> #include
> > +<linux/firmware/imx/ipc.h> #include <linux/mailbox_client.h>
> > +
> > +#define IMX_SC_IRQ_FUNC_STATUS 2
> > +#define IMX_SC_IRQ_NUM_GROUP 4
> > +
> > +static u32 mu_resource_id;
> > +
> > +struct imx_sc_msg_irq_get_status {
> > + struct imx_sc_rpc_msg hdr;
> > + union {
> > + struct {
> > + u16 resource;
> > + u8 group;
> > + u8 reserved;
> > + } __packed req;
> > + struct {
> > + u32 status;
> > + } resp;
> > + } data;
> > +};
> > +
> > +static struct imx_sc_ipc *imx_sc_irq_ipc_handle; static struct
> > +work_struct imx_sc_irq_work; static
> > +BLOCKING_NOTIFIER_HEAD(imx_scu_irq_notifier_chain);
> > +
> > +int imx_scu_irq_register_notifier(struct notifier_block *nb) {
> > + return blocking_notifier_chain_register(
>
> We probably can use atomic_notifier_call_chain as it's used for irq function.
Agree, it makes more sense to use it in interrupt context. Will update it in V6.
>
> > + &imx_scu_irq_notifier_chain, nb);
> > +}
> > +EXPORT_SYMBOL(imx_scu_irq_register_notifier);
> > +
> > +int imx_scu_irq_unregister_notifier(struct notifier_block *nb) {
> > + return blocking_notifier_chain_unregister(
> > + &imx_scu_irq_notifier_chain, nb);
> > +}
> > +EXPORT_SYMBOL(imx_scu_irq_unregister_notifier);
> > +
> > +static int imx_scu_irq_notifier_call_chain(unsigned long status, u8
> > +*group) {
> > + return blocking_notifier_call_chain(&imx_scu_irq_notifier_chain,
> > + status, (void *)group);
> > +}
> > +
> > +static void imx_scu_irq_work_handler(struct work_struct *work) {
> > + struct imx_sc_msg_irq_get_status msg;
> > + struct imx_sc_rpc_msg *hdr = &msg.hdr;
> > + u32 irq_status;
> > + int ret;
> > + u8 i;
> > +
> > + for (i = 0; i < IMX_SC_IRQ_NUM_GROUP; i++) {
> > + hdr->ver = IMX_SC_RPC_VERSION;
> > + hdr->svc = IMX_SC_RPC_SVC_IRQ;
> > + hdr->func = IMX_SC_IRQ_FUNC_STATUS;
> > + hdr->size = 2;
> > +
> > + msg.data.req.resource = mu_resource_id;
> > + msg.data.req.group = i;
> > +
> > + ret = imx_scu_call_rpc(imx_sc_irq_ipc_handle, &msg, true);
> > + if (ret) {
> > + pr_err("get irq group %d status failed, ret %d\n",
> > + i, ret);
> > + return;
> > + }
> > +
> > + irq_status = msg.data.resp.status;
> > + if (!irq_status)
> > + continue;
> > +
> > + imx_scu_irq_notifier_call_chain(irq_status, &i);
> > + }
> > +}
> > +
> > +static void imx_scu_irq_callback(struct mbox_client *c, void *msg) {
> > + schedule_work(&imx_sc_irq_work);
> > +}
> > +
> > +int imx_scu_enable_general_irq_channel(struct device *dev) {
> > + struct of_phandle_args spec;
> > + struct mbox_client *cl;
> > + struct mbox_chan *ch;
> > + int ret = 0, i = 0;
> > +
> > + cl = devm_kzalloc(dev, sizeof(*cl), GFP_KERNEL);
> > + if (!cl)
> > + return -ENOMEM;
> > +
> > + cl->dev = dev;
> > + cl->rx_callback = imx_scu_irq_callback;
> > +
> > + /* SCU general IRQ uses general interrupt channel 3 */
> > + ch = mbox_request_channel_byname(cl, "gip3");
> > + if (IS_ERR(ch)) {
> > + ret = PTR_ERR(ch);
> > + dev_err(dev, "failed to request mbox chan gip3, ret %d\n",
> ret);
>
> There may be memory leak as this function is optional in imx-scu.c.
> So here seems to miss a devm_kfree
Correct, I need to handle it, will add it in V6.
Thanks,
Anson.
>
> Regards
> Dong Aisheng
>
> > + return ret;
> > + }
> > +
> > + ret = imx_scu_get_handle(&imx_sc_irq_ipc_handle);
> > + if (ret)
> > + return ret;
> > +
> > + INIT_WORK(&imx_sc_irq_work, imx_scu_irq_work_handler);
> > +
> > + if (!of_parse_phandle_with_args(dev->of_node, "mboxes",
> > + "#mbox-cells", 0, &spec))
> > + i = of_alias_get_id(spec.np, "mu");
> > +
> > + /* use mu1 as general mu irq channel if failed */
> > + if (i < 0)
> > + i = 1;
> > +
> > + mu_resource_id = IMX_SC_R_MU_0A + i;
> > +
> > + return ret;
> > +}
> > +EXPORT_SYMBOL(imx_scu_enable_general_irq_channel);
> > diff --git a/drivers/firmware/imx/imx-scu.c
> > b/drivers/firmware/imx/imx-scu.c index 2bb1a19..04a24a8 100644
> > --- a/drivers/firmware/imx/imx-scu.c
> > +++ b/drivers/firmware/imx/imx-scu.c
> > @@ -10,6 +10,7 @@
> > #include <linux/err.h>
> > #include <linux/firmware/imx/types.h> #include
> > <linux/firmware/imx/ipc.h>
> > +#include <linux/firmware/imx/sci.h>
> > #include <linux/interrupt.h>
> > #include <linux/irq.h>
> > #include <linux/kernel.h>
> > @@ -246,6 +247,11 @@ static int imx_scu_probe(struct platform_device
> > *pdev)
> >
> > imx_sc_ipc_handle = sc_ipc;
> >
> > + ret = imx_scu_enable_general_irq_channel(dev);
> > + if (ret)
> > + dev_warn(dev,
> > + "failed to enable general irq channel: %d\n", ret);
> > +
> > dev_info(dev, "NXP i.MX SCU Initialized\n");
> >
> > return devm_of_platform_populate(dev); diff --git
> > a/include/linux/firmware/imx/sci.h b/include/linux/firmware/imx/sci.h
> > index ebc5509..918fa16 100644
> > --- a/include/linux/firmware/imx/sci.h
> > +++ b/include/linux/firmware/imx/sci.h
> > @@ -15,4 +15,8 @@
> >
> > #include <linux/firmware/imx/svc/misc.h> #include
> > <linux/firmware/imx/svc/pm.h>
> > +
> > +int imx_scu_enable_general_irq_channel(struct device *dev); int
> > +imx_scu_irq_register_notifier(struct notifier_block *nb); int
> > +imx_scu_irq_unregister_notifier(struct notifier_block *nb);
> > #endif /* _SC_SCI_H */
> > --
> > 2.7.4