diff mbox series

[v2,5/5] reset: Add support for resets provided by SCMI

Message ID 20190806170208.6787-6-sudeep.holla@arm.com
State Accepted
Commit c8ae9c2da1cc5d18b6d51d10160508a3dc3436bf
Headers show
Series firmware: arm_scmi: add SCMI v2.0 fastchannels and reset protocol support | expand

Commit Message

Sudeep Holla Aug. 6, 2019, 5:02 p.m. UTC 
On some ARM based systems, a separate Cortex-M based System Control
Processor(SCP) provides the overall power, clock, reset and system
control. System Control and Management Interface(SCMI) Message Protocol
is defined for the communication between the Application Cores(AP)
and the SCP.

Adds support for the resets provided using SCMI protocol for performing
reset management of various devices present on the SoC. Various reset
functionalities are achieved by the means of different ARM SCMI device
operations provided by the ARM SCMI framework.

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

---
 MAINTAINERS                |   1 +
 drivers/reset/Kconfig      |  11 ++++
 drivers/reset/Makefile     |   1 +
 drivers/reset/reset-scmi.c | 126 +++++++++++++++++++++++++++++++++++++
 4 files changed, 139 insertions(+)
 create mode 100644 drivers/reset/reset-scmi.c

v1->v2:
	- Renamed RESET_ARM_SCMI to RESET_SCMI and reworded Kconfig text
	- Dropped unused struct device pointer from scmi_reset_data
	- Added to_scmi_handle which helped to remove some repetitive code
	- Fixed some doxygen comments
	- Initialised rcdev.nr_resets
	- Fixed MODULE_DESCRIPTION

-- 
2.17.1

Comments

Philipp Zabel Aug. 7, 2019, 8:04 a.m. UTC | #1 
On Tue, 2019-08-06 at 18:02 +0100, Sudeep Holla wrote:
> On some ARM based systems, a separate Cortex-M based System Control

> Processor(SCP) provides the overall power, clock, reset and system

> control. System Control and Management Interface(SCMI) Message Protocol

> is defined for the communication between the Application Cores(AP)

> and the SCP.

> 

> Adds support for the resets provided using SCMI protocol for performing

> reset management of various devices present on the SoC. Various reset

> functionalities are achieved by the means of different ARM SCMI device

> operations provided by the ARM SCMI framework.

> 

> Cc: Philipp Zabel <p.zabel@pengutronix.de>

> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

> ---

>  MAINTAINERS                |   1 +

>  drivers/reset/Kconfig      |  11 ++++

>  drivers/reset/Makefile     |   1 +

>  drivers/reset/reset-scmi.c | 126 +++++++++++++++++++++++++++++++++++++

>  4 files changed, 139 insertions(+)

>  create mode 100644 drivers/reset/reset-scmi.c

> 

> v1->v2:

> 	- Renamed RESET_ARM_SCMI to RESET_SCMI and reworded Kconfig text

> 	- Dropped unused struct device pointer from scmi_reset_data

> 	- Added to_scmi_handle which helped to remove some repetitive code

> 	- Fixed some doxygen comments

> 	- Initialised rcdev.nr_resets

> 	- Fixed MODULE_DESCRIPTION

> 

> diff --git a/MAINTAINERS b/MAINTAINERS

> index 6426db5198f0..f4af5c59c116 100644

> --- a/MAINTAINERS

> +++ b/MAINTAINERS

> @@ -15545,6 +15545,7 @@ F:	drivers/clk/clk-sc[mp]i.c

>  F:	drivers/cpufreq/sc[mp]i-cpufreq.c

>  F:	drivers/firmware/arm_scpi.c

>  F:	drivers/firmware/arm_scmi/

> +F:	drivers/reset/reset-scmi.c

>  F:	include/linux/sc[mp]i_protocol.h

>  

>  SYSTEM RESET/SHUTDOWN DRIVERS

> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig

> index 21efb7d39d62..4178ac11ba85 100644

> --- a/drivers/reset/Kconfig

> +++ b/drivers/reset/Kconfig

> @@ -116,6 +116,17 @@ config RESET_QCOM_PDC

>  	  to control reset signals provided by PDC for Modem, Compute,

>  	  Display, GPU, Debug, AOP, Sensors, Audio, SP and APPS.

>  

> +config RESET_SCMI

> +	tristate "Reset driver controlled via ARM SCMI interface"

> +	depends on ARM_SCMI_PROTOCOL || COMPILE_TEST

> +	default ARM_SCMI_PROTOCOL

> +	help

> +	  This driver provides support for reset signal/domains that are

> +	  controlled by firmware that implements the SCMI interface.

> +

> +	  This driver uses SCMI Message Protocol to interact with the

> +	  firmware controlling all the reset signals.

> +

>  config RESET_SIMPLE

>  	bool "Simple Reset Controller Driver" if COMPILE_TEST

>  	default ARCH_STM32 || ARCH_STRATIX10 || ARCH_SUNXI || ARCH_ZX || ARCH_ASPEED || ARCH_BITMAIN

> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile

> index 61456b8f659c..cf60ce526064 100644

> --- a/drivers/reset/Makefile

> +++ b/drivers/reset/Makefile

> @@ -18,6 +18,7 @@ obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o

>  obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o

>  obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o

>  obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o

> +obj-$(CONFIG_RESET_SCMI) += reset-scmi.o

>  obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o

>  obj-$(CONFIG_RESET_STM32MP157) += reset-stm32mp1.o

>  obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o

> diff --git a/drivers/reset/reset-scmi.c b/drivers/reset/reset-scmi.c

> new file mode 100644

> index 000000000000..5e976a02a6cc

> --- /dev/null

> +++ b/drivers/reset/reset-scmi.c

> @@ -0,0 +1,126 @@

> +// SPDX-License-Identifier: GPL-2.0

> +/*

> + * ARM System Control and Management Interface (ARM SCMI) reset driver

> + *

> + * Copyright (C) 2019 ARM Ltd.

> + */

> +

> +#include <linux/module.h>

> +#include <linux/mutex.h>


You can drop mutex.h, it is unused.

> +#include <linux/of.h>

> +#include <linux/platform_device.h>


This is not a platform device driver. Better replace this with

#include <linux/device.h>

> +#include <linux/reset-controller.h>

> +#include <linux/scmi_protocol.h>

> +

> +/**

> + * struct scmi_reset_data - reset controller information structure

> + * @rcdev: reset controller entity

> + * @handle: ARM SCMI handle used for communication with system controller

> + * @dev: reset controller device pointer


Drop this line, dev has been removed from struct scmi_reset_data.

> + */

> +struct scmi_reset_data {

> +	struct reset_controller_dev rcdev;

> +	const struct scmi_handle *handle;

> +};

> +

> +#define to_scmi_reset_data(p)	container_of((p), struct scmi_reset_data, rcdev)

> +#define to_scmi_handle(p)	(to_scmi_reset_data(p)->handle)

[...]

Apart from these,
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>


regards
Philipp
Sudeep Holla Aug. 7, 2019, 10:31 a.m. UTC | #2 
On Wed, Aug 07, 2019 at 10:04:26AM +0200, Philipp Zabel wrote:
> On Tue, 2019-08-06 at 18:02 +0100, Sudeep Holla wrote:

> > On some ARM based systems, a separate Cortex-M based System Control

> > Processor(SCP) provides the overall power, clock, reset and system

> > control. System Control and Management Interface(SCMI) Message Protocol

> > is defined for the communication between the Application Cores(AP)

> > and the SCP.

> >

> > Adds support for the resets provided using SCMI protocol for performing

> > reset management of various devices present on the SoC. Various reset

> > functionalities are achieved by the means of different ARM SCMI device

> > operations provided by the ARM SCMI framework.

> >

> > Cc: Philipp Zabel <p.zabel@pengutronix.de>

> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

> > ---

> >  MAINTAINERS                |   1 +

> >  drivers/reset/Kconfig      |  11 ++++

> >  drivers/reset/Makefile     |   1 +

> >  drivers/reset/reset-scmi.c | 126 +++++++++++++++++++++++++++++++++++++

> >  4 files changed, 139 insertions(+)

> >  create mode 100644 drivers/reset/reset-scmi.c

> >

> > v1->v2:

> > 	- Renamed RESET_ARM_SCMI to RESET_SCMI and reworded Kconfig text

> > 	- Dropped unused struct device pointer from scmi_reset_data

> > 	- Added to_scmi_handle which helped to remove some repetitive code

> > 	- Fixed some doxygen comments

> > 	- Initialised rcdev.nr_resets

> > 	- Fixed MODULE_DESCRIPTION

> >

> > diff --git a/MAINTAINERS b/MAINTAINERS

> > index 6426db5198f0..f4af5c59c116 100644

> > --- a/MAINTAINERS

> > +++ b/MAINTAINERS

> > @@ -15545,6 +15545,7 @@ F:	drivers/clk/clk-sc[mp]i.c

> >  F:	drivers/cpufreq/sc[mp]i-cpufreq.c

> >  F:	drivers/firmware/arm_scpi.c

> >  F:	drivers/firmware/arm_scmi/

> > +F:	drivers/reset/reset-scmi.c

> >  F:	include/linux/sc[mp]i_protocol.h

> >

> >  SYSTEM RESET/SHUTDOWN DRIVERS

> > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig

> > index 21efb7d39d62..4178ac11ba85 100644

> > --- a/drivers/reset/Kconfig

> > +++ b/drivers/reset/Kconfig

> > @@ -116,6 +116,17 @@ config RESET_QCOM_PDC

> >  	  to control reset signals provided by PDC for Modem, Compute,

> >  	  Display, GPU, Debug, AOP, Sensors, Audio, SP and APPS.

> >

> > +config RESET_SCMI

> > +	tristate "Reset driver controlled via ARM SCMI interface"

> > +	depends on ARM_SCMI_PROTOCOL || COMPILE_TEST

> > +	default ARM_SCMI_PROTOCOL

> > +	help

> > +	  This driver provides support for reset signal/domains that are

> > +	  controlled by firmware that implements the SCMI interface.

> > +

> > +	  This driver uses SCMI Message Protocol to interact with the

> > +	  firmware controlling all the reset signals.

> > +

> >  config RESET_SIMPLE

> >  	bool "Simple Reset Controller Driver" if COMPILE_TEST

> >  	default ARCH_STM32 || ARCH_STRATIX10 || ARCH_SUNXI || ARCH_ZX || ARCH_ASPEED || ARCH_BITMAIN

> > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile

> > index 61456b8f659c..cf60ce526064 100644

> > --- a/drivers/reset/Makefile

> > +++ b/drivers/reset/Makefile

> > @@ -18,6 +18,7 @@ obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o

> >  obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o

> >  obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o

> >  obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o

> > +obj-$(CONFIG_RESET_SCMI) += reset-scmi.o

> >  obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o

> >  obj-$(CONFIG_RESET_STM32MP157) += reset-stm32mp1.o

> >  obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o

> > diff --git a/drivers/reset/reset-scmi.c b/drivers/reset/reset-scmi.c

> > new file mode 100644

> > index 000000000000..5e976a02a6cc

> > --- /dev/null

> > +++ b/drivers/reset/reset-scmi.c

> > @@ -0,0 +1,126 @@

> > +// SPDX-License-Identifier: GPL-2.0

> > +/*

> > + * ARM System Control and Management Interface (ARM SCMI) reset driver

> > + *

> > + * Copyright (C) 2019 ARM Ltd.

> > + */

> > +

> > +#include <linux/module.h>

> > +#include <linux/mutex.h>

>

> You can drop mutex.h, it is unused.

>

> > +#include <linux/of.h>

> > +#include <linux/platform_device.h>

>

> This is not a platform device driver. Better replace this with

>

> #include <linux/device.h>

>

> > +#include <linux/reset-controller.h>

> > +#include <linux/scmi_protocol.h>

> > +

> > +/**

> > + * struct scmi_reset_data - reset controller information structure

> > + * @rcdev: reset controller entity

> > + * @handle: ARM SCMI handle used for communication with system controller

> > + * @dev: reset controller device pointer

>

> Drop this line, dev has been removed from struct scmi_reset_data.

>


All the above 3 are now fixed.

> > + */

> > +struct scmi_reset_data {

> > +	struct reset_controller_dev rcdev;

> > +	const struct scmi_handle *handle;

> > +};

> > +

> > +#define to_scmi_reset_data(p)	container_of((p), struct scmi_reset_data, rcdev)

> > +#define to_scmi_handle(p)	(to_scmi_reset_data(p)->handle)

> [...]

>

> Apart from these,

> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

>


Thanks

--
Regards,
Sudeep
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 6426db5198f0..f4af5c59c116 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15545,6 +15545,7 @@  F:	drivers/clk/clk-sc[mp]i.c
 F:	drivers/cpufreq/sc[mp]i-cpufreq.c
 F:	drivers/firmware/arm_scpi.c
 F:	drivers/firmware/arm_scmi/
+F:	drivers/reset/reset-scmi.c
 F:	include/linux/sc[mp]i_protocol.h
 
 SYSTEM RESET/SHUTDOWN DRIVERS
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 21efb7d39d62..4178ac11ba85 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -116,6 +116,17 @@  config RESET_QCOM_PDC
 	  to control reset signals provided by PDC for Modem, Compute,
 	  Display, GPU, Debug, AOP, Sensors, Audio, SP and APPS.
 
+config RESET_SCMI
+	tristate "Reset driver controlled via ARM SCMI interface"
+	depends on ARM_SCMI_PROTOCOL || COMPILE_TEST
+	default ARM_SCMI_PROTOCOL
+	help
+	  This driver provides support for reset signal/domains that are
+	  controlled by firmware that implements the SCMI interface.
+
+	  This driver uses SCMI Message Protocol to interact with the
+	  firmware controlling all the reset signals.
+
 config RESET_SIMPLE
 	bool "Simple Reset Controller Driver" if COMPILE_TEST
 	default ARCH_STM32 || ARCH_STRATIX10 || ARCH_SUNXI || ARCH_ZX || ARCH_ASPEED || ARCH_BITMAIN
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 61456b8f659c..cf60ce526064 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -18,6 +18,7 @@  obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
 obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
 obj-$(CONFIG_RESET_QCOM_AOSS) += reset-qcom-aoss.o
 obj-$(CONFIG_RESET_QCOM_PDC) += reset-qcom-pdc.o
+obj-$(CONFIG_RESET_SCMI) += reset-scmi.o
 obj-$(CONFIG_RESET_SIMPLE) += reset-simple.o
 obj-$(CONFIG_RESET_STM32MP157) += reset-stm32mp1.o
 obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
diff --git a/drivers/reset/reset-scmi.c b/drivers/reset/reset-scmi.c
new file mode 100644
index 000000000000..5e976a02a6cc
--- /dev/null
+++ b/drivers/reset/reset-scmi.c
@@ -0,0 +1,126 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ARM System Control and Management Interface (ARM SCMI) reset driver
+ *
+ * Copyright (C) 2019 ARM Ltd.
+ */
+
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/scmi_protocol.h>
+
+/**
+ * struct scmi_reset_data - reset controller information structure
+ * @rcdev: reset controller entity
+ * @handle: ARM SCMI handle used for communication with system controller
+ * @dev: reset controller device pointer
+ */
+struct scmi_reset_data {
+	struct reset_controller_dev rcdev;
+	const struct scmi_handle *handle;
+};
+
+#define to_scmi_reset_data(p)	container_of((p), struct scmi_reset_data, rcdev)
+#define to_scmi_handle(p)	(to_scmi_reset_data(p)->handle)
+
+/**
+ * scmi_reset_assert() - assert device reset
+ * @rcdev: reset controller entity
+ * @id: ID of the reset to be asserted
+ *
+ * This function implements the reset driver op to assert a device's reset
+ * using the ARM SCMI protocol.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int
+scmi_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	const struct scmi_handle *handle = to_scmi_handle(rcdev);
+
+	return handle->reset_ops->assert(handle, id);
+}
+
+/**
+ * scmi_reset_deassert() - deassert device reset
+ * @rcdev: reset controller entity
+ * @id: ID of the reset to be deasserted
+ *
+ * This function implements the reset driver op to deassert a device's reset
+ * using the ARM SCMI protocol.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int
+scmi_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	const struct scmi_handle *handle = to_scmi_handle(rcdev);
+
+	return handle->reset_ops->deassert(handle, id);
+}
+
+/**
+ * scmi_reset_reset() - reset the device
+ * @rcdev: reset controller entity
+ * @id: ID of the reset signal to be reset(assert + deassert)
+ *
+ * This function implements the reset driver op to trigger a device's
+ * reset signal using the ARM SCMI protocol.
+ *
+ * Return: 0 for successful request, else a corresponding error value
+ */
+static int
+scmi_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	const struct scmi_handle *handle = to_scmi_handle(rcdev);
+
+	return handle->reset_ops->reset(handle, id);
+}
+
+static const struct reset_control_ops scmi_reset_ops = {
+	.assert		= scmi_reset_assert,
+	.deassert	= scmi_reset_deassert,
+	.reset		= scmi_reset_reset,
+};
+
+static int scmi_reset_probe(struct scmi_device *sdev)
+{
+	struct scmi_reset_data *data;
+	struct device *dev = &sdev->dev;
+	struct device_node *np = dev->of_node;
+	const struct scmi_handle *handle = sdev->handle;
+
+	if (!handle || !handle->reset_ops)
+		return -ENODEV;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->rcdev.ops = &scmi_reset_ops;
+	data->rcdev.owner = THIS_MODULE;
+	data->rcdev.of_node = np;
+	data->rcdev.nr_resets = handle->reset_ops->num_domains_get(handle);
+
+	return devm_reset_controller_register(dev, &data->rcdev);
+}
+
+static const struct scmi_device_id scmi_id_table[] = {
+	{ SCMI_PROTOCOL_RESET },
+	{ },
+};
+MODULE_DEVICE_TABLE(scmi, scmi_id_table);
+
+static struct scmi_driver scmi_reset_driver = {
+	.name = "scmi-reset",
+	.probe = scmi_reset_probe,
+	.id_table = scmi_id_table,
+};
+module_scmi_driver(scmi_reset_driver);
+
+MODULE_AUTHOR("Sudeep Holla <sudeep.holla@arm.com>");
+MODULE_DESCRIPTION("ARM SCMI reset controller driver");
+MODULE_LICENSE("GPL v2");