From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre-Louis Bossart Subject: Re: [alsa-devel] [RESEND PATCH v4 2/4] soundwire: core: add device tree support for slave devices Date: Fri, 23 Aug 2019 10:44:30 -0500 Message-ID: <2f1b5e2e-4699-1d06-e28e-708d5ed99b6a@linux.intel.com> References: <20190822233759.12663-1-srinivas.kandagatla@linaro.org> <20190822233759.12663-3-srinivas.kandagatla@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190822233759.12663-3-srinivas.kandagatla@linaro.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Srinivas Kandagatla , broonie@kernel.org, robh+dt@kernel.org, vkoul@kernel.org Cc: devicetree@vger.kernel.org, alsa-devel@alsa-project.org, bgoswami@codeaurora.org, spapothi@codeaurora.org, lgirdwood@gmail.com, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org On 8/22/19 6:37 PM, Srinivas Kandagatla wrote: > This patch adds support to parsing device tree based > SoundWire slave devices. > > Signed-off-by: Srinivas Kandagatla > --- > drivers/soundwire/bus.c | 2 ++ > drivers/soundwire/bus.h | 1 + > drivers/soundwire/slave.c | 52 +++++++++++++++++++++++++++++++++++++++ > 3 files changed, 55 insertions(+) > > diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c > index 49f64b2115b9..c2eaeb5c38ed 100644 > --- a/drivers/soundwire/bus.c > +++ b/drivers/soundwire/bus.c > @@ -77,6 +77,8 @@ int sdw_add_bus_master(struct sdw_bus *bus) > */ > if (IS_ENABLED(CONFIG_ACPI) && ACPI_HANDLE(bus->dev)) > ret = sdw_acpi_find_slaves(bus); > + else if (IS_ENABLED(CONFIG_OF) && bus->dev->of_node) > + ret = sdw_of_find_slaves(bus); > else > ret = -ENOTSUPP; /* No ACPI/DT so error out */ > > diff --git a/drivers/soundwire/bus.h b/drivers/soundwire/bus.h > index 3048ca153f22..ee46befedbd1 100644 > --- a/drivers/soundwire/bus.h > +++ b/drivers/soundwire/bus.h > @@ -15,6 +15,7 @@ static inline int sdw_acpi_find_slaves(struct sdw_bus *bus) > } > #endif > > +int sdw_of_find_slaves(struct sdw_bus *bus); > void sdw_extract_slave_id(struct sdw_bus *bus, > u64 addr, struct sdw_slave_id *id); > > diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c > index f39a5815e25d..3ef265d2ee89 100644 > --- a/drivers/soundwire/slave.c > +++ b/drivers/soundwire/slave.c > @@ -2,6 +2,7 @@ > // Copyright(c) 2015-17 Intel Corporation. > > #include > +#include > #include > #include > #include "bus.h" > @@ -35,6 +36,7 @@ static int sdw_slave_add(struct sdw_bus *bus, > > slave->dev.release = sdw_slave_release; > slave->dev.bus = &sdw_bus_type; > + slave->dev.of_node = of_node_get(to_of_node(fwnode)); > slave->bus = bus; > slave->status = SDW_SLAVE_UNATTACHED; > slave->dev_num = 0; > @@ -112,3 +114,53 @@ int sdw_acpi_find_slaves(struct sdw_bus *bus) > } > > #endif > + > +/* > + * sdw_of_find_slaves() - Find Slave devices in master device tree node > + * @bus: SDW bus instance > + * > + * Scans Master DT node for SDW child Slave devices and registers it. > + */ > +int sdw_of_find_slaves(struct sdw_bus *bus) > +{ > + struct device *dev = bus->dev; > + struct device_node *node; > + > + for_each_child_of_node(bus->dev->of_node, node) { > + int link_id, sdw_version, ret, len; > + const char *compat = NULL; > + struct sdw_slave_id id; > + const __be32 *addr; > + > + compat = of_get_property(node, "compatible", NULL); > + if (!compat) > + continue; > + > + ret = sscanf(compat, "sdw%01x%04hx%04hx%02hhx", &sdw_version, > + &id.mfg_id, &id.part_id, &id.class_id); > + > + if (ret != 4) { > + dev_err(dev, "Invalid compatible string found %s\n", > + compat); > + continue; > + } > + > + addr = of_get_property(node, "reg", &len); > + if (!addr || (len < 2 * sizeof(u32))) { > + dev_err(dev, "Invalid Instance and Link ID\n"); > + continue; > + } > + > + id.unique_id = be32_to_cpup(addr++); > + link_id = be32_to_cpup(addr); So here the link ID is obviously not in the address, so you are not using the MIPI spec as we discussed initially? > + id.sdw_version = sdw_version; > + > + /* Check for link_id match */ > + if (link_id != bus->link_id) > + continue; > + > + sdw_slave_add(bus, &id, of_fwnode_handle(node)); > + } > + > + return 0; > +} >