From 513ca82d8982463aca98aa01dcf584e0b4fc0982 Mon Sep 17 00:00:00 2001 From: Patrick Venture Date: Mon, 12 Apr 2021 12:45:20 -0700 Subject: hw/i2c: add match method for device search At the start of an i2c transaction, the i2c bus searches its list of children to identify which devices correspond to the address (or broadcast). Now the I2CSlave device has a method "match" that encapsulates the lookup behavior. This allows the behavior to be changed to support devices, such as i2c muxes. Tested: A BMC firmware was booted to userspace and i2c devices were detected. Signed-off-by: Patrick Venture Reviewed-by: Hao Wu Message-Id: <20210412194522.664594-3-venture@google.com> Signed-off-by: Corey Minyard --- hw/i2c/core.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) (limited to 'hw/i2c/core.c') diff --git a/hw/i2c/core.c b/hw/i2c/core.c index 21ec52ac5a..d03b0eea5c 100644 --- a/hw/i2c/core.c +++ b/hw/i2c/core.c @@ -118,10 +118,9 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv) QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) { DeviceState *qdev = kid->child; I2CSlave *candidate = I2C_SLAVE(qdev); - if ((candidate->address == address) || (bus->broadcast)) { - node = g_malloc(sizeof(struct I2CNode)); - node->elt = candidate; - QLIST_INSERT_HEAD(&bus->current_devs, node, next); + sc = I2C_SLAVE_GET_CLASS(candidate); + if (sc->match_and_add(candidate, address, bus->broadcast, + &bus->current_devs)) { if (!bus->broadcast) { break; } @@ -290,12 +289,28 @@ I2CSlave *i2c_slave_create_simple(I2CBus *bus, const char *name, uint8_t addr) return dev; } +static bool i2c_slave_match(I2CSlave *candidate, uint8_t address, + bool broadcast, I2CNodeList *current_devs) +{ + if ((candidate->address == address) || (broadcast)) { + I2CNode *node = g_malloc(sizeof(struct I2CNode)); + node->elt = candidate; + QLIST_INSERT_HEAD(current_devs, node, next); + return true; + } + + /* Not found and not broadcast. */ + return false; +} + static void i2c_slave_class_init(ObjectClass *klass, void *data) { DeviceClass *k = DEVICE_CLASS(klass); + I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass); set_bit(DEVICE_CATEGORY_MISC, k->categories); k->bus_type = TYPE_I2C_BUS; device_class_set_props(k, i2c_props); + sc->match_and_add = i2c_slave_match; } static const TypeInfo i2c_slave_type_info = { -- cgit v1.2.3-55-g7522 From 3f9b32595e785c79720ed174198472c3d4d32c03 Mon Sep 17 00:00:00 2001 From: Patrick Venture Date: Mon, 12 Apr 2021 12:45:21 -0700 Subject: hw/i2c: move search to i2c_scan_bus method Moves the search for matching devices on an i2c bus into a separate method. This allows for an object that owns an I2CBus can avoid duplicating this method. Tested: A BMC firmware was booted to userspace and i2c devices were detected. Signed-off-by: Patrick Venture Reviewed-by: Hao Wu Message-Id: <20210412194522.664594-4-venture@google.com> Signed-off-by: Corey Minyard --- hw/i2c/core.c | 38 ++++++++++++++++++++++++++------------ include/hw/i2c/i2c.h | 2 ++ 2 files changed, 28 insertions(+), 12 deletions(-) (limited to 'hw/i2c/core.c') diff --git a/hw/i2c/core.c b/hw/i2c/core.c index d03b0eea5c..3a7bae311d 100644 --- a/hw/i2c/core.c +++ b/hw/i2c/core.c @@ -77,6 +77,30 @@ int i2c_bus_busy(I2CBus *bus) return !QLIST_EMPTY(&bus->current_devs); } +bool i2c_scan_bus(I2CBus *bus, uint8_t address, bool broadcast, + I2CNodeList *current_devs) +{ + BusChild *kid; + + QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) { + DeviceState *qdev = kid->child; + I2CSlave *candidate = I2C_SLAVE(qdev); + I2CSlaveClass *sc = I2C_SLAVE_GET_CLASS(candidate); + + if (sc->match_and_add(candidate, address, broadcast, current_devs)) { + if (!broadcast) { + return true; + } + } + } + + /* + * If broadcast was true, and the list was full or empty, return true. If + * broadcast was false, return false. + */ + return broadcast; +} + /* TODO: Make this handle multiple masters. */ /* * Start or continue an i2c transaction. When this is called for the @@ -93,7 +117,6 @@ int i2c_bus_busy(I2CBus *bus) */ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv) { - BusChild *kid; I2CSlaveClass *sc; I2CNode *node; bool bus_scanned = false; @@ -115,17 +138,8 @@ int i2c_start_transfer(I2CBus *bus, uint8_t address, int recv) * terminating the previous transaction. */ if (QLIST_EMPTY(&bus->current_devs)) { - QTAILQ_FOREACH(kid, &bus->qbus.children, sibling) { - DeviceState *qdev = kid->child; - I2CSlave *candidate = I2C_SLAVE(qdev); - sc = I2C_SLAVE_GET_CLASS(candidate); - if (sc->match_and_add(candidate, address, bus->broadcast, - &bus->current_devs)) { - if (!bus->broadcast) { - break; - } - } - } + /* Disregard whether devices were found. */ + (void)i2c_scan_bus(bus, address, bus->broadcast, &bus->current_devs); bus_scanned = true; } diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index 9b8b95ff4a..ff4129ea70 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -87,6 +87,8 @@ void i2c_nack(I2CBus *bus); int i2c_send_recv(I2CBus *bus, uint8_t *data, bool send); int i2c_send(I2CBus *bus, uint8_t data); uint8_t i2c_recv(I2CBus *bus); +bool i2c_scan_bus(I2CBus *bus, uint8_t address, bool broadcast, + I2CNodeList *current_devs); /** * Create an I2C slave device on the heap. -- cgit v1.2.3-55-g7522