Messages in this thread | | | Date | Wed, 7 Aug 2019 11:35:49 +0100 | From | Sudeep Holla <> | Subject | Re: [PATCH v2 4/5] firmware: arm_scmi: Add RESET protocol in SCMI v2.0 |
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On Wed, Aug 07, 2019 at 10:17:50AM +0200, Philipp Zabel wrote: > 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, >
Ah, new function to me. I will take a look, may need more place to fix.
> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> >
Thanks, Sudeep
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