Messages in this thread | | | Subject | Re: [PATCH v2 4/5] firmware: arm_scmi: Add RESET protocol in SCMI v2.0 | From | Philipp Zabel <> | Date | Wed, 07 Aug 2019 10:17:50 +0200 |
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On Tue, 2019-08-06 at 18:02 +0100, Sudeep Holla wrote: > SCMIv2.0 adds a new Reset Management Protocol to manage various reset > states a given device or domain can enter. Device(s) that can be > collectively reset through a common reset signal constitute a reset > domain for the firmware. > > A reset domain can be reset autonomously or explicitly through assertion > and de-assertion of the signal. When autonomous reset is chosen, the > firmware is responsible for taking the necessary steps to reset the > domain and to subsequently bring it out of reset. When explicit reset is > chosen, the caller has to specifically assert and then de-assert the > reset signal by issuing two separate RESET commands. > > Add the basic SCMI reset infrastructure that can be used by Linux > reset controller driver. > > Cc: Philipp Zabel <p.zabel@pengutronix.de> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> > --- > drivers/firmware/arm_scmi/Makefile | 2 +- > drivers/firmware/arm_scmi/reset.c | 231 +++++++++++++++++++++++++++++ > include/linux/scmi_protocol.h | 26 ++++ > 3 files changed, 258 insertions(+), 1 deletion(-) > create mode 100644 drivers/firmware/arm_scmi/reset.c > > diff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile > index c47d28d556b6..5f298f00a82e 100644 > --- a/drivers/firmware/arm_scmi/Makefile > +++ b/drivers/firmware/arm_scmi/Makefile > @@ -2,5 +2,5 @@ > obj-y = scmi-bus.o scmi-driver.o scmi-protocols.o > scmi-bus-y = bus.o > scmi-driver-y = driver.o > -scmi-protocols-y = base.o clock.o perf.o power.o sensors.o > +scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o > obj-$(CONFIG_ARM_SCMI_POWER_DOMAIN) += scmi_pm_domain.o > diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c > new file mode 100644 > index 000000000000..11cb8b5ccf34 > --- /dev/null > +++ b/drivers/firmware/arm_scmi/reset.c > @@ -0,0 +1,231 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * System Control and Management Interface (SCMI) Reset Protocol > + * > + * Copyright (C) 2019 ARM Ltd. > + */ > + > +#include "common.h" > + > +enum scmi_reset_protocol_cmd { > + RESET_DOMAIN_ATTRIBUTES = 0x3, > + RESET = 0x4, > + RESET_NOTIFY = 0x5, > +}; > + > +enum scmi_reset_protocol_notify { > + RESET_ISSUED = 0x0, > +}; > + > +#define NUM_RESET_DOMAIN_MASK 0xffff > +#define RESET_NOTIFY_ENABLE BIT(0) > + > +struct scmi_msg_resp_reset_domain_attributes { > + __le32 attributes; > +#define SUPPORTS_ASYNC_RESET(x) ((x) & BIT(31)) > +#define SUPPORTS_NOTIFY_RESET(x) ((x) & BIT(30)) > + __le32 latency; > + u8 name[SCMI_MAX_STR_SIZE]; > +}; > + > +struct scmi_msg_reset_domain_reset { > + __le32 domain_id; > + __le32 flags; > +#define AUTONOMOUS_RESET BIT(0) > +#define EXPLICIT_RESET_ASSERT BIT(1) > +#define ASYNCHRONOUS_RESET BIT(2) > + __le32 reset_state; > +#define ARCH_RESET_TYPE BIT(31) > +#define COLD_RESET_STATE BIT(0) > +#define ARCH_COLD_RESET (ARCH_RESET_TYPE | COLD_RESET_STATE) > +}; > + > +struct reset_dom_info { > + bool async_reset; > + bool reset_notify; > + u32 latency_us; > + char name[SCMI_MAX_STR_SIZE]; > +}; > + > +struct scmi_reset_info { > + int num_domains; > + struct reset_dom_info *dom_info; > +}; > + > +static int scmi_reset_attributes_get(const struct scmi_handle *handle, > + struct scmi_reset_info *pi) > +{ > + int ret; > + struct scmi_xfer *t; > + u32 *attr; > + > + ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES, > + SCMI_PROTOCOL_RESET, 0, sizeof(*attr), &t); > + if (ret) > + return ret; > + > + attr = t->rx.buf; > + > + ret = scmi_do_xfer(handle, t); > + if (!ret) > + pi->num_domains = le32_to_cpu(*attr) & NUM_RESET_DOMAIN_MASK; > + > + scmi_xfer_put(handle, t); > + return ret; > +} > + > +static int > +scmi_reset_domain_attributes_get(const struct scmi_handle *handle, u32 domain, > + struct reset_dom_info *dom_info) > +{ > + int ret; > + struct scmi_xfer *t; > + struct scmi_msg_resp_reset_domain_attributes *attr; > + > + ret = scmi_xfer_get_init(handle, RESET_DOMAIN_ATTRIBUTES, > + SCMI_PROTOCOL_RESET, sizeof(domain), > + sizeof(*attr), &t); > + if (ret) > + return ret; > + > + *(__le32 *)t->tx.buf = cpu_to_le32(domain);
Should this use put_unaligned_le32(domain, t->tx.buf); ? Either way,
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
regards Philipp
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