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| author | Peter Maydell <peter.maydell@linaro.org> | 2024-03-12 13:42:49 +0000 |
|---|---|---|
| committer | Peter Maydell <peter.maydell@linaro.org> | 2024-03-12 13:42:49 +0000 |
| commit | fe6d4434d2531f8bc6fffc7878c801e8d8190c5d (patch) | |
| tree | 620f53e7007bd343b2dd8b4d263cbc4df34a81ad /hw/gpio/pcf8574.c | |
| parent | 8f3f329f5e0117bd1a23a79ab751f8a7d3471e4b (diff) | |
| parent | afc8b05cea14b2eea6f1eaa640f74b21486fca48 (diff) | |
| download | focaccia-qemu-fe6d4434d2531f8bc6fffc7878c801e8d8190c5d.tar.gz focaccia-qemu-fe6d4434d2531f8bc6fffc7878c801e8d8190c5d.zip | |
Merge tag 'hw-misc-20240312' of https://github.com/philmd/qemu into staging
Misc HW patch queue - Rename hw/ide/ahci-internal.h for consistency (Zoltan) - More convenient PCI hotplug trace events (Vladimir) - Short CLI option to add drives for sam460ex machine (Zoltan) - More missing ERRP_GUARD() macros (Zhao) - Avoid faulting when unmapped I/O BAR is accessed on SPARC EBUS (Mark) - Remove unused includes in hw/core/ (Zhao) - New PCF8574 GPIO over I2C model (Dmitriy) - Require ObjC on Darwin macOS by default (Peter) - Corrected "-smp parameter=1" placement in docs/ (Zhao) # -----BEGIN PGP SIGNATURE----- # # iQIzBAABCAAdFiEE+qvnXhKRciHc/Wuy4+MsLN6twN4FAmXwEJkACgkQ4+MsLN6t # wN4A3hAAngVu7VmyrfqYF6jfDMUuRGYaKf4D73/KF6R1PsU+nJdN7UAkECLj8o7g # mkcAQu1U3fKCUssF6MJ2a3kU+rD1OkkA/ZcitzgWwEjCK8KVjtMt2HzEqX+B/X+e # RUVjXMOMkyV48MF0+yLhJz+lQiDpEBFVxIgssPBNUz1Pw9IfoXp29Bfz+bYBThS4 # ywAdvCefNzSira0Nt6RWTnvgBHB/1+aLy1uMSt0Xu926zcqoxQJ0b//0flYL8vAf # JuSSZuiXPw+oAc3qG3d6aPl3g8DrFn3pvPD471KlFQAnB0dlhEZZqNBPvraySpHl # h04Y8teHYj9XfxPtaWfaEdgQCazdkKFR/q7E5c9GU00Rf469BJeuo9Pzkm4kWfbU # sbCl8em5biVZ5DpBIOMT3/D0JOyGf7/CM8y5c3Jc92hapx2NdSszkvCicrDE1+i0 # zEr4N0P/F2x5KFVFkQ3Xzv2Jtzw+iXj6kSE5a5/64GMK29Mqu/EPaSkvwGDQOs3N # QJ9mpa4gg47g310a0/nH0i5eVbvGVuzcCMP6VXOBVr18cJ7JFQFFiYcvoTDXNQ2m # sq5xUelRimnWfKpawomJXkS+/j0usH61/aQBuDKfj45i8/XFRejCIk0gMWQ9hjyD # no1HqDN8CVXtiPNSinC7ctNHU5ClS0xO/BRl0h3PGC7Bl+A2eVY= # =JQg1 # -----END PGP SIGNATURE----- # gpg: Signature made Tue 12 Mar 2024 08:21:45 GMT # gpg: using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE # gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full] # Primary key fingerprint: FAAB E75E 1291 7221 DCFD 6BB2 E3E3 2C2C DEAD C0DE * tag 'hw-misc-20240312' of https://github.com/philmd/qemu: docs/about/deprecated.rst: Move SMP configurations item to system emulator section meson.build: Always require an objc compiler on macos hosts hw/gpio: introduce pcf8574 driver hw/core: Cleanup unused included headers in numa.c hw/core: Cleanup unused included header in machine-qmp-cmds.c hw/core: Cleanup unused included headers in cpu-common.c sun4u: remap ebus BAR0 to use unassigned_io_ops instead of alias to PCI IO space hw/misc/ivshmem: Fix missing ERRP_GUARD() for error_prepend() hw/core/qdev-properties-system: Fix missing ERRP_GUARD() for error_prepend() hw/core/loader-fit: Fix missing ERRP_GUARD() for error_prepend() hw/ppc/sam460ex: Support short options for adding drives hw/pci: add some convenient trace-events for pcie and shpc hotplug hw/ide/ahci: Rename ahci_internal.h to ahci-internal.h Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'hw/gpio/pcf8574.c')
| -rw-r--r-- | hw/gpio/pcf8574.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/hw/gpio/pcf8574.c b/hw/gpio/pcf8574.c new file mode 100644 index 0000000000..d37909e2ad --- /dev/null +++ b/hw/gpio/pcf8574.c @@ -0,0 +1,162 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +/* + * NXP PCF8574 8-port I2C GPIO expansion chip. + * Copyright (c) 2024 KNS Group (YADRO). + * Written by Dmitrii Sharikhin <d.sharikhin@yadro.com> + */ + +#include "qemu/osdep.h" +#include "hw/i2c/i2c.h" +#include "hw/gpio/pcf8574.h" +#include "hw/irq.h" +#include "migration/vmstate.h" +#include "qemu/log.h" +#include "qemu/module.h" +#include "qom/object.h" + +/* + * PCF8574 and compatible chips incorporate quasi-bidirectional + * IO. Electrically it means that device sustain pull-up to line + * unless IO port is configured as output _and_ driven low. + * + * IO access is implemented as simple I2C single-byte read + * or write operation. So, to configure line to input user write 1 + * to corresponding bit. To configure line to output and drive it low + * user write 0 to corresponding bit. + * + * In essence, user can think of quasi-bidirectional IO as + * open-drain line, except presence of builtin rising edge acceleration + * embedded in PCF8574 IC + * + * PCF8574 has interrupt request line, which is being pulled down when + * port line state differs from last read. Port read operation clears + * state and INT line returns to high state via pullup. + */ + +OBJECT_DECLARE_SIMPLE_TYPE(PCF8574State, PCF8574) + +#define PORTS_COUNT (8) + +struct PCF8574State { + I2CSlave parent_obj; + uint8_t lastrq; /* Last requested state. If changed - assert irq */ + uint8_t input; /* external electrical line state */ + uint8_t output; /* Pull-up (1) or drive low (0) on bit */ + qemu_irq handler[PORTS_COUNT]; + qemu_irq intrq; /* External irq request */ +}; + +static void pcf8574_reset(DeviceState *dev) +{ + PCF8574State *s = PCF8574(dev); + s->lastrq = MAKE_64BIT_MASK(0, PORTS_COUNT); + s->input = MAKE_64BIT_MASK(0, PORTS_COUNT); + s->output = MAKE_64BIT_MASK(0, PORTS_COUNT); +} + +static inline uint8_t pcf8574_line_state(PCF8574State *s) +{ + /* we driving line low or external circuit does that */ + return s->input & s->output; +} + +static uint8_t pcf8574_rx(I2CSlave *i2c) +{ + PCF8574State *s = PCF8574(i2c); + uint8_t linestate = pcf8574_line_state(s); + if (s->lastrq != linestate) { + s->lastrq = linestate; + if (s->intrq) { + qemu_set_irq(s->intrq, 1); + } + } + return linestate; +} + +static int pcf8574_tx(I2CSlave *i2c, uint8_t data) +{ + PCF8574State *s = PCF8574(i2c); + uint8_t prev; + uint8_t diff; + uint8_t actual; + int line = 0; + + prev = pcf8574_line_state(s); + s->output = data; + actual = pcf8574_line_state(s); + + for (diff = (actual ^ prev); diff; diff &= ~(1 << line)) { + line = ctz32(diff); + if (s->handler[line]) { + qemu_set_irq(s->handler[line], (actual >> line) & 1); + } + } + + if (s->intrq) { + qemu_set_irq(s->intrq, actual == s->lastrq); + } + + return 0; +} + +static const VMStateDescription vmstate_pcf8574 = { + .name = "pcf8574", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_I2C_SLAVE(parent_obj, PCF8574State), + VMSTATE_UINT8(lastrq, PCF8574State), + VMSTATE_UINT8(input, PCF8574State), + VMSTATE_UINT8(output, PCF8574State), + VMSTATE_END_OF_LIST() + } +}; + +static void pcf8574_gpio_set(void *opaque, int line, int level) +{ + PCF8574State *s = (PCF8574State *) opaque; + assert(line >= 0 && line < ARRAY_SIZE(s->handler)); + + if (level) { + s->input |= (1 << line); + } else { + s->input &= ~(1 << line); + } + + if (pcf8574_line_state(s) != s->lastrq && s->intrq) { + qemu_set_irq(s->intrq, 0); + } +} + +static void pcf8574_realize(DeviceState *dev, Error **errp) +{ + PCF8574State *s = PCF8574(dev); + + qdev_init_gpio_in(dev, pcf8574_gpio_set, ARRAY_SIZE(s->handler)); + qdev_init_gpio_out(dev, s->handler, ARRAY_SIZE(s->handler)); + qdev_init_gpio_out_named(dev, &s->intrq, "nINT", 1); +} + +static void pcf8574_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); + + k->recv = pcf8574_rx; + k->send = pcf8574_tx; + dc->realize = pcf8574_realize; + dc->reset = pcf8574_reset; + dc->vmsd = &vmstate_pcf8574; +} + +static const TypeInfo pcf8574_infos[] = { + { + .name = TYPE_PCF8574, + .parent = TYPE_I2C_SLAVE, + .instance_size = sizeof(PCF8574State), + .class_init = pcf8574_class_init, + } +}; + +DEFINE_TYPES(pcf8574_infos); |