diff options
| -rw-r--r-- | MAINTAINERS | 6 | ||||
| -rw-r--r-- | hw/i2c/Kconfig | 4 | ||||
| -rw-r--r-- | hw/i2c/core.c | 55 | ||||
| -rw-r--r-- | hw/i2c/i2c_mux_pca954x.c | 290 | ||||
| -rw-r--r-- | hw/i2c/meson.build | 1 | ||||
| -rw-r--r-- | hw/i2c/trace-events | 5 | ||||
| -rw-r--r-- | include/hw/i2c/i2c.h | 17 | ||||
| -rw-r--r-- | include/hw/i2c/i2c_mux_pca954x.h | 19 |
8 files changed, 383 insertions, 14 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index f73354f..78561a2 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2024,6 +2024,12 @@ S: Maintained F: hw/net/tulip.c F: hw/net/tulip.h +pca954x +M: Patrick Venture <venture@google.com> +S: Maintained +F: hw/i2c/i2c_mux_pca954x.c +F: include/hw/i2c/i2c_mux_pca954x.h + Generic Loader M: Alistair Francis <alistair@alistair23.me> S: Maintained diff --git a/hw/i2c/Kconfig b/hw/i2c/Kconfig index 09642a6..8d120a2 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/core.c b/hw/i2c/core.c index 21ec52a..3a7bae3 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; @@ -115,18 +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); - if ((candidate->address == address) || (bus->broadcast)) { - node = g_malloc(sizeof(struct I2CNode)); - node->elt = candidate; - QLIST_INSERT_HEAD(&bus->current_devs, node, next); - if (!bus->broadcast) { - break; - } - } - } + /* Disregard whether devices were found. */ + (void)i2c_scan_bus(bus, address, bus->broadcast, &bus->current_devs); bus_scanned = true; } @@ -290,12 +303,28 @@ 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/hw/i2c/i2c_mux_pca954x.c b/hw/i2c/i2c_mux_pca954x.c new file mode 100644 index 0000000..847c599 --- /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 cdcd694..dd3aef0 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 82fe6f9..82f19e6 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.h b/include/hw/i2c/i2c.h index 277dd9f..ff4129e 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 { @@ -58,9 +69,11 @@ 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; }; @@ -74,6 +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. diff --git a/include/hw/i2c/i2c_mux_pca954x.h b/include/hw/i2c/i2c_mux_pca954x.h new file mode 100644 index 0000000..8aaf9bb --- /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 |