[PATCH V4 2/4] firmware: imx: enable imx scu general irq function

Anson Huang anson.huang at nxp.com
Sun Mar 17 19:58:53 PDT 2019



Best Regards!
Anson Huang

> -----Original Message-----
> From: Aisheng Dong
> Sent: 2019年3月15日 19:05
> To: Anson Huang <anson.huang at nxp.com>; robh+dt at kernel.org;
> mark.rutland at arm.com; shawnguo at kernel.org; s.hauer at pengutronix.de;
> kernel at pengutronix.de; festevam at gmail.com; a.zummo at towertech.it;
> alexandre.belloni at bootlin.com; ulf.hansson at linaro.org; Daniel Baluta
> <daniel.baluta at nxp.com>; devicetree at vger.kernel.org; linux-
> kernel at vger.kernel.org; linux-arm-kernel at lists.infradead.org; linux-
> rtc at vger.kernel.org
> Cc: dl-linux-imx <linux-imx at nxp.com>
> Subject: RE: [PATCH V4 2/4] firmware: imx: enable imx scu general irq
> function
> 
> > From: Anson Huang
> >
> > 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 at nxp.com>
> > ---
> > Changes since V3:
> > 	- use alias to get general MU interrupt channel id and then get
> > resource ID,
> > 	  this is to support different MU instance;
> > 	- add return value check for imx_scu_enable_general_irq_channel().
> > ---
> >  drivers/firmware/imx/imx-scu.c   | 116
> > +++++++++++++++++++++++++++++++++++++++
> 
> Generally I would suggest to put scu irq support into another separate file
> under The same folder to make code clean from function point of view.

OK, I will add a imx-scu-irq.c file to support SCU irq function.

> 
> >  include/linux/firmware/imx/sci.h |   3 +
> >  2 files changed, 119 insertions(+)
> >
> > diff --git a/drivers/firmware/imx/imx-scu.c
> > b/drivers/firmware/imx/imx-scu.c index 2bb1a19..1dcd7b3 100644
> > --- a/drivers/firmware/imx/imx-scu.c
> > +++ b/drivers/firmware/imx/imx-scu.c
> > @@ -7,6 +7,7 @@
> >   *
> >   */
> >
> > +#include <dt-bindings/firmware/imx/rsrc.h>
> >  #include <linux/err.h>
> >  #include <linux/firmware/imx/types.h>  #include
> > <linux/firmware/imx/ipc.h> @@ -21,6 +22,8 @@
> >
> >  #define SCU_MU_CHAN_NUM		8
> >  #define MAX_RX_TIMEOUT		(msecs_to_jiffies(30))
> > +#define IMX_SC_IRQ_FUNC_STATUS	2
> > +#define IMX_SC_IRQ_NUM_GROUP	6
> >
> >  struct imx_sc_chan {
> >  	struct imx_sc_ipc *sc_ipc;
> > @@ -41,6 +44,7 @@ struct imx_sc_ipc {
> >  	u32 *msg;
> >  	u8 rx_size;
> >  	u8 count;
> > +	u32 mu_resource_id;
> 
> I feel it a bit strange to put this mu id in struct imx_sc_ipc.

Since I will create new file imx-sc-irq.c, I will move this out of the struct and
use define a static variable for it.

> 
> >  };
> >
> >  /*
> > @@ -77,7 +81,23 @@ static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] =
> {
> >  	-EIO,	 /* IMX_SC_ERR_FAIL */
> >  };
> >
> > +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;
> > +		} __packed resp;
> 
> No packed needed for this one

OK

> 
> > +	} data;
> > +};
> > +
> >  static struct imx_sc_ipc *imx_sc_ipc_handle;
> > +static struct work_struct imx_sc_general_irq_work; static
> > +BLOCKING_NOTIFIER_HEAD(imx_scu_notifier_chain);
> 
> Imx_scu_irq_xxx

OK

> 
> >
> >  static inline int imx_sc_to_linux_errno(int errno)  { @@ -194,9
> > +214,90 @@ int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg,
> > bool have_resp)  } EXPORT_SYMBOL(imx_scu_call_rpc);
> >
> > +int imx_scu_register_notifier(struct notifier_block *nb) {
> > +	return blocking_notifier_chain_register(&imx_scu_notifier_chain,
> > +nb); } EXPORT_SYMBOL(imx_scu_register_notifier);
> > +
> > +int imx_scu_unregister_notifier(struct notifier_block *nb) {
> > +	return blocking_notifier_chain_unregister(&imx_scu_notifier_chain,
> > +nb); } EXPORT_SYMBOL(imx_scu_unregister_notifier);
> > +
> > +static int imx_scu_notifier_call_chain(unsigned long status, u8
> > +*group) {
> > +	return blocking_notifier_call_chain(&imx_scu_notifier_chain,
> > +					    status, (void *)group);
> > +}
> > +
> > +static void imx_scu_general_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++) {
> 
> Do we need to support all irq group?

After further check, maybe we can change the group number to 4, ONLY supporting those
kernel related features, others are NOT needed in kernel now.

34 #define SC_IRQ_GROUP_TEMP       0U   /* Temp interrupts */
 35 #define SC_IRQ_GROUP_WDOG       1U   /* Watchdog interrupts */
 36 #define SC_IRQ_GROUP_RTC        2U   /* RTC interrupts */
 37 #define SC_IRQ_GROUP_WAKE       3U   /* Wakeup interrupts */
 38 #define SC_IRQ_GROUP_SYSCTR     4U   /* System counter interrupts */
 39 #define SC_IRQ_GROUP_REBOOTED   5U   /* Partition reboot complete */
 40 #define SC_IRQ_GROUP_REBOOT     6U   /* Partition reboot starting */

> 
> > +		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 = imx_sc_ipc_handle-
> >mu_resource_id;
> > +		msg.data.req.group = i;
> > +
> > +		ret = imx_scu_call_rpc(imx_sc_ipc_handle, &msg, true);
> > +		if (ret) {
> > +			pr_err("get irq status failed, ret %d\n", ret);
> 
> Can the error output more useful information?

Yes, I will add group number in the error message.

> 
> > +			return;
> > +		}
> > +
> > +		irq_status = msg.data.resp.status;
> > +		if (!irq_status)
> > +			continue;
> > +
> > +		imx_scu_notifier_call_chain(irq_status, &i);
> > +	}
> > +}
> > +
> > +static void imx_scu_rxdb_callback(struct mbox_client *c, void *msg) {
> 
> Imx_scu_irq_callback

OK

> 
> > +	schedule_work(&imx_sc_general_irq_work);
> > +}
> > +
> > +static int imx_scu_enable_general_irq_channel(struct device *dev) {
> > +	struct mbox_client *cl;
> > +	struct mbox_chan *ch;
> > +	int ret = 0;
> > +
> > +	cl = devm_kzalloc(dev, sizeof(*cl), GFP_KERNEL);
> > +	if (!cl)
> > +		return -ENOMEM;
> > +
> > +	cl->dev = dev;
> > +	cl->rx_callback = imx_scu_rxdb_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);
> > +		return ret;
> > +	}
> > +
> > +	INIT_WORK(&imx_sc_general_irq_work,
> > imx_scu_general_irq_work_handler);
> > +
> > +	return ret;
> > +}
> > +
> >  static int imx_scu_probe(struct platform_device *pdev)  {
> >  	struct device *dev = &pdev->dev;
> > +	struct of_phandle_args spec;
> >  	struct imx_sc_ipc *sc_ipc;
> >  	struct imx_sc_chan *sc_chan;
> >  	struct mbox_client *cl;
> > @@ -246,6 +347,21 @@ 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);
> > +
> 
> It does not make sense to parse again if failed. Pls put them into one function.

Will put the mu id parse into imx_scu_enable_general_irq_channel function and
ONLY parse it when irq channel enabled successfully.

> 
> > +	if (!of_parse_phandle_with_args(dev->of_node, "mboxes",
> > +				       "#mbox-cells", 0, &spec))
> > +		i = of_alias_get_id(spec.np, "mu");
> 
> This needs a binding doc for mailbox (mu).

Will add it.

> 
> > +
> > +	/* use mu1 as general mu irq channel if failed */
> > +	if (i < 0)
> > +		i = 1;
> > +
> > +	imx_sc_ipc_handle->mu_resource_id = IMX_SC_R_MU_0A + i;
> > +
> >  	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..9d608db 100644
> > --- a/include/linux/firmware/imx/sci.h
> > +++ b/include/linux/firmware/imx/sci.h
> > @@ -15,4 +15,7 @@
> >
> >  #include <linux/firmware/imx/svc/misc.h>  #include
> > <linux/firmware/imx/svc/pm.h>
> > +
> > +int imx_scu_register_notifier(struct notifier_block *nb); int
> > +imx_scu_unregister_notifier(struct notifier_block *nb);
> 
> imx_scu_irq_xxx

OK

Thanks,
Anson.

> 
> Regards
> Dong Aisheng
> 
> >  #endif /* _SC_SCI_H */
> > --
> > 2.7.4



More information about the linux-arm-kernel mailing list