From b98ec6896ee88f1dcdd7098af25bcb6ee0fc50f0 Mon Sep 17 00:00:00 2001 From: Patrick Venture Date: Mon, 12 Apr 2021 12:45:19 -0700 Subject: hw/i2c: name I2CNode list in I2CBus To enable passing the current_devs field as a parameter, we need to use a named struct type. Tested: BMC firmware with i2c devices booted to userspace. Signed-off-by: Patrick Venture Reviewed-by: Hao Wu Reviewed-by: Philippe Mathieu-Daudé Message-Id: <20210412194522.664594-2-venture@google.com> Signed-off-by: Corey Minyard --- include/hw/i2c/i2c.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index 277dd9f2d6..1f7c268c86 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -58,9 +58,11 @@ struct I2CNode { QLIST_ENTRY(I2CNode) next; }; +typedef QLIST_HEAD(I2CNodeList, I2CNode) I2CNodeList; + struct I2CBus { BusState qbus; - QLIST_HEAD(, I2CNode) current_devs; + I2CNodeList current_devs; uint8_t saved_address; bool broadcast; }; -- cgit v1.2.3-55-g7522 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 +++++++++++++++++++---- include/hw/i2c/i2c.h | 11 +++++++++++ 2 files changed, 30 insertions(+), 4 deletions(-) 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 = { diff --git a/include/hw/i2c/i2c.h b/include/hw/i2c/i2c.h index 1f7c268c86..9b8b95ff4a 100644 --- a/include/hw/i2c/i2c.h +++ b/include/hw/i2c/i2c.h @@ -16,6 +16,7 @@ enum i2c_event { I2C_NACK /* Masker NACKed a receive byte. */ }; +typedef struct I2CNodeList I2CNodeList; #define TYPE_I2C_SLAVE "i2c-slave" OBJECT_DECLARE_TYPE(I2CSlave, I2CSlaveClass, @@ -39,6 +40,16 @@ struct I2CSlaveClass { * return code is not used and should be zero. */ int (*event)(I2CSlave *s, enum i2c_event event); + + /* + * Check if this device matches the address provided. Returns bool of + * true if it matches (or broadcast), and updates the device list, false + * otherwise. + * + * If broadcast is true, match should add the device and return true. + */ + bool (*match_and_add)(I2CSlave *candidate, uint8_t address, bool broadcast, + I2CNodeList *current_devs); }; struct I2CSlave { -- 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(-) 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 From 065177eeceff552a5316bff9435188b50a2da1b6 Mon Sep 17 00:00:00 2001 From: Patrick Venture Date: Mon, 12 Apr 2021 12:45:22 -0700 Subject: hw/i2c: add pca954x i2c-mux switch The pca954x is an i2c mux, and this adds support for two variants of this device: the pca9546 and pca9548. This device is very common on BMCs to route a different channel to each PCIe i2c bus downstream from the BMC. Signed-off-by: Patrick Venture Reviewed-by: Hao Wu Reviewed-by: Havard Skinnemoen Message-Id: <20210412194522.664594-5-venture@google.com> Signed-off-by: Corey Minyard --- MAINTAINERS | 6 + hw/i2c/Kconfig | 4 + hw/i2c/i2c_mux_pca954x.c | 290 +++++++++++++++++++++++++++++++++++++++ hw/i2c/meson.build | 1 + hw/i2c/trace-events | 5 + include/hw/i2c/i2c_mux_pca954x.h | 19 +++ 6 files changed, 325 insertions(+) create mode 100644 hw/i2c/i2c_mux_pca954x.c create mode 100644 include/hw/i2c/i2c_mux_pca954x.h diff --git a/MAINTAINERS b/MAINTAINERS index 36055f14c5..34452de9b4 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2040,6 +2040,12 @@ S: Maintained F: hw/net/tulip.c F: hw/net/tulip.h +pca954x +M: Patrick Venture +S: Maintained +F: hw/i2c/i2c_mux_pca954x.c +F: include/hw/i2c/i2c_mux_pca954x.h + Generic Loader M: Alistair Francis S: Maintained diff --git a/hw/i2c/Kconfig b/hw/i2c/Kconfig index 09642a6dcb..8d120a25d5 100644 --- a/hw/i2c/Kconfig +++ b/hw/i2c/Kconfig @@ -28,3 +28,7 @@ config IMX_I2C config MPC_I2C bool select I2C + +config PCA954X + bool + select I2C diff --git a/hw/i2c/i2c_mux_pca954x.c b/hw/i2c/i2c_mux_pca954x.c new file mode 100644 index 0000000000..847c59921c --- /dev/null +++ b/hw/i2c/i2c_mux_pca954x.c @@ -0,0 +1,290 @@ +/* + * I2C multiplexer for PCA954x series of I2C multiplexer/switch chips. + * + * Copyright 2021 Google LLC + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "hw/i2c/i2c.h" +#include "hw/i2c/i2c_mux_pca954x.h" +#include "hw/i2c/smbus_slave.h" +#include "hw/qdev-core.h" +#include "hw/sysbus.h" +#include "qemu/log.h" +#include "qemu/module.h" +#include "qemu/queue.h" +#include "qom/object.h" +#include "trace.h" + +#define PCA9548_CHANNEL_COUNT 8 +#define PCA9546_CHANNEL_COUNT 4 + +/* + * struct Pca954xChannel - The i2c mux device will have N of these states + * that own the i2c channel bus. + * @bus: The owned channel bus. + * @enabled: Is this channel active? + */ +typedef struct Pca954xChannel { + SysBusDevice parent; + + I2CBus *bus; + + bool enabled; +} Pca954xChannel; + +#define TYPE_PCA954X_CHANNEL "pca954x-channel" +#define PCA954X_CHANNEL(obj) \ + OBJECT_CHECK(Pca954xChannel, (obj), TYPE_PCA954X_CHANNEL) + +/* + * struct Pca954xState - The pca954x state object. + * @control: The value written to the mux control. + * @channel: The set of i2c channel buses that act as channels which own the + * i2c children. + */ +typedef struct Pca954xState { + SMBusDevice parent; + + uint8_t control; + + /* The channel i2c buses. */ + Pca954xChannel channel[PCA9548_CHANNEL_COUNT]; +} Pca954xState; + +/* + * struct Pca954xClass - The pca954x class object. + * @nchans: The number of i2c channels this device has. + */ +typedef struct Pca954xClass { + SMBusDeviceClass parent; + + uint8_t nchans; +} Pca954xClass; + +#define TYPE_PCA954X "pca954x" +OBJECT_DECLARE_TYPE(Pca954xState, Pca954xClass, PCA954X) + +/* + * For each channel, if it's enabled, recursively call match on those children. + */ +static bool pca954x_match(I2CSlave *candidate, uint8_t address, + bool broadcast, + I2CNodeList *current_devs) +{ + Pca954xState *mux = PCA954X(candidate); + Pca954xClass *mc = PCA954X_GET_CLASS(mux); + int i; + + /* They are talking to the mux itself (or all devices enabled). */ + if ((candidate->address == address) || broadcast) { + I2CNode *node = g_malloc(sizeof(struct I2CNode)); + node->elt = candidate; + QLIST_INSERT_HEAD(current_devs, node, next); + if (!broadcast) { + return true; + } + } + + for (i = 0; i < mc->nchans; i++) { + if (!mux->channel[i].enabled) { + continue; + } + + if (i2c_scan_bus(mux->channel[i].bus, address, broadcast, + current_devs)) { + if (!broadcast) { + return true; + } + } + } + + /* If we arrived here we didn't find a match, return broadcast. */ + return broadcast; +} + +static void pca954x_enable_channel(Pca954xState *s, uint8_t enable_mask) +{ + Pca954xClass *mc = PCA954X_GET_CLASS(s); + int i; + + /* + * For each channel, check if their bit is set in enable_mask and if yes, + * enable it, otherwise disable, hide it. + */ + for (i = 0; i < mc->nchans; i++) { + if (enable_mask & (1 << i)) { + s->channel[i].enabled = true; + } else { + s->channel[i].enabled = false; + } + } +} + +static void pca954x_write(Pca954xState *s, uint8_t data) +{ + s->control = data; + pca954x_enable_channel(s, data); + + trace_pca954x_write_bytes(data); +} + +static int pca954x_write_data(SMBusDevice *d, uint8_t *buf, uint8_t len) +{ + Pca954xState *s = PCA954X(d); + + if (len == 0) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: writing empty data\n", __func__); + return -1; + } + + /* + * len should be 1, because they write one byte to enable/disable channels. + */ + if (len > 1) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: extra data after channel selection mask\n", + __func__); + return -1; + } + + pca954x_write(s, buf[0]); + return 0; +} + +static uint8_t pca954x_read_byte(SMBusDevice *d) +{ + Pca954xState *s = PCA954X(d); + uint8_t data = s->control; + trace_pca954x_read_data(data); + return data; +} + +static void pca954x_enter_reset(Object *obj, ResetType type) +{ + Pca954xState *s = PCA954X(obj); + /* Reset will disable all channels. */ + pca954x_write(s, 0); +} + +I2CBus *pca954x_i2c_get_bus(I2CSlave *mux, uint8_t channel) +{ + Pca954xClass *pc = PCA954X_GET_CLASS(mux); + Pca954xState *pca954x = PCA954X(mux); + + g_assert(channel < pc->nchans); + return I2C_BUS(qdev_get_child_bus(DEVICE(&pca954x->channel[channel]), + "i2c-bus")); +} + +static void pca954x_channel_init(Object *obj) +{ + Pca954xChannel *s = PCA954X_CHANNEL(obj); + s->bus = i2c_init_bus(DEVICE(s), "i2c-bus"); + + /* Start all channels as disabled. */ + s->enabled = false; +} + +static void pca954x_channel_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + dc->desc = "Pca954x Channel"; +} + +static void pca9546_class_init(ObjectClass *klass, void *data) +{ + Pca954xClass *s = PCA954X_CLASS(klass); + s->nchans = PCA9546_CHANNEL_COUNT; +} + +static void pca9548_class_init(ObjectClass *klass, void *data) +{ + Pca954xClass *s = PCA954X_CLASS(klass); + s->nchans = PCA9548_CHANNEL_COUNT; +} + +static void pca954x_realize(DeviceState *dev, Error **errp) +{ + Pca954xState *s = PCA954X(dev); + Pca954xClass *c = PCA954X_GET_CLASS(s); + int i; + + /* SMBus modules. Cannot fail. */ + for (i = 0; i < c->nchans; i++) { + sysbus_realize(SYS_BUS_DEVICE(&s->channel[i]), &error_abort); + } +} + +static void pca954x_init(Object *obj) +{ + Pca954xState *s = PCA954X(obj); + Pca954xClass *c = PCA954X_GET_CLASS(obj); + int i; + + /* Only initialize the children we expect. */ + for (i = 0; i < c->nchans; i++) { + object_initialize_child(obj, "channel[*]", &s->channel[i], + TYPE_PCA954X_CHANNEL); + } +} + +static void pca954x_class_init(ObjectClass *klass, void *data) +{ + I2CSlaveClass *sc = I2C_SLAVE_CLASS(klass); + ResettableClass *rc = RESETTABLE_CLASS(klass); + DeviceClass *dc = DEVICE_CLASS(klass); + SMBusDeviceClass *k = SMBUS_DEVICE_CLASS(klass); + + sc->match_and_add = pca954x_match; + + rc->phases.enter = pca954x_enter_reset; + + dc->desc = "Pca954x i2c-mux"; + dc->realize = pca954x_realize; + + k->write_data = pca954x_write_data; + k->receive_byte = pca954x_read_byte; +} + +static const TypeInfo pca954x_info[] = { + { + .name = TYPE_PCA954X, + .parent = TYPE_SMBUS_DEVICE, + .instance_size = sizeof(Pca954xState), + .instance_init = pca954x_init, + .class_size = sizeof(Pca954xClass), + .class_init = pca954x_class_init, + .abstract = true, + }, + { + .name = TYPE_PCA9546, + .parent = TYPE_PCA954X, + .class_init = pca9546_class_init, + }, + { + .name = TYPE_PCA9548, + .parent = TYPE_PCA954X, + .class_init = pca9548_class_init, + }, + { + .name = TYPE_PCA954X_CHANNEL, + .parent = TYPE_SYS_BUS_DEVICE, + .class_init = pca954x_channel_class_init, + .instance_size = sizeof(Pca954xChannel), + .instance_init = pca954x_channel_init, + } +}; + +DEFINE_TYPES(pca954x_info) diff --git a/hw/i2c/meson.build b/hw/i2c/meson.build index cdcd694a7f..dd3aef02b2 100644 --- a/hw/i2c/meson.build +++ b/hw/i2c/meson.build @@ -14,4 +14,5 @@ i2c_ss.add(when: 'CONFIG_SMBUS_EEPROM', if_true: files('smbus_eeprom.c')) i2c_ss.add(when: 'CONFIG_VERSATILE_I2C', if_true: files('versatile_i2c.c')) i2c_ss.add(when: 'CONFIG_OMAP', if_true: files('omap_i2c.c')) i2c_ss.add(when: 'CONFIG_PPC4XX', if_true: files('ppc4xx_i2c.c')) +i2c_ss.add(when: 'CONFIG_PCA954X', if_true: files('i2c_mux_pca954x.c')) softmmu_ss.add_all(when: 'CONFIG_I2C', if_true: i2c_ss) diff --git a/hw/i2c/trace-events b/hw/i2c/trace-events index 82fe6f965f..82f19e6a2d 100644 --- a/hw/i2c/trace-events +++ b/hw/i2c/trace-events @@ -26,3 +26,8 @@ npcm7xx_smbus_recv_byte(const char *id, uint8_t value) "%s recv byte: 0x%02x" npcm7xx_smbus_stop(const char *id) "%s stopping" npcm7xx_smbus_nack(const char *id) "%s nacking" npcm7xx_smbus_recv_fifo(const char *id, uint8_t received, uint8_t expected) "%s recv fifo: received %u, expected %u" + +# i2c-mux-pca954x.c + +pca954x_write_bytes(uint8_t value) "PCA954X write data: 0x%02x" +pca954x_read_data(uint8_t value) "PCA954X read data: 0x%02x" diff --git a/include/hw/i2c/i2c_mux_pca954x.h b/include/hw/i2c/i2c_mux_pca954x.h new file mode 100644 index 0000000000..8aaf9bbc39 --- /dev/null +++ b/include/hw/i2c/i2c_mux_pca954x.h @@ -0,0 +1,19 @@ +#ifndef QEMU_I2C_MUX_PCA954X +#define QEMU_I2C_MUX_PCA954X + +#include "hw/i2c/i2c.h" + +#define TYPE_PCA9546 "pca9546" +#define TYPE_PCA9548 "pca9548" + +/** + * Retrieves the i2c bus associated with the specified channel on this i2c + * mux. + * @mux: an i2c mux device. + * @channel: the i2c channel requested + * + * Returns: a pointer to the associated i2c bus. + */ +I2CBus *pca954x_i2c_get_bus(I2CSlave *mux, uint8_t channel); + +#endif -- cgit v1.2.3-55-g7522