On Tue, Dec 16, 2014 at 3:47 PM, Peter Crosthwaite <peter.crosthwa...@xilinx.com> wrote: > On Wed, Dec 10, 2014 at 12:46 AM, Alistair Francis <alistai...@gmail.com> > wrote: >> This patch adds the stm32f2xx USART controller >> (UART also uses the same controller). >> >> Signed-off-by: Alistair Francis <alistai...@gmail.com> >> --- >> V6: >> - Rename to STM32F2XX >> - Fix up unimplemented printing >> - Add a qemu_chr_accept() >> V3: >> - Update debug printing >> V2: >> - Drop charecters if the device is not enabled >> - Thanks to Peter C >> >> default-configs/arm-softmmu.mak | 1 + >> hw/char/Makefile.objs | 1 + >> hw/char/stm32f2xx_usart.c | 219 >> ++++++++++++++++++++++++++++++++++++++ >> include/hw/char/stm32f2xx_usart.h | 69 ++++++++++++ >> 4 files changed, 290 insertions(+) >> create mode 100644 hw/char/stm32f2xx_usart.c >> create mode 100644 include/hw/char/stm32f2xx_usart.h >> >> diff --git a/default-configs/arm-softmmu.mak >> b/default-configs/arm-softmmu.mak >> index faea100..1348104 100644 >> --- a/default-configs/arm-softmmu.mak >> +++ b/default-configs/arm-softmmu.mak >> @@ -79,6 +79,7 @@ CONFIG_REALVIEW=y >> CONFIG_ZAURUS=y >> CONFIG_ZYNQ=y >> CONFIG_STM32F2XX_TIMER=y >> +CONFIG_STM32F2XX_USART=y >> >> CONFIG_VERSATILE_PCI=y >> CONFIG_VERSATILE_I2C=y >> diff --git a/hw/char/Makefile.objs b/hw/char/Makefile.objs >> index 317385d..5931cc8 100644 >> --- a/hw/char/Makefile.objs >> +++ b/hw/char/Makefile.objs >> @@ -15,6 +15,7 @@ obj-$(CONFIG_OMAP) += omap_uart.o >> obj-$(CONFIG_SH4) += sh_serial.o >> obj-$(CONFIG_PSERIES) += spapr_vty.o >> obj-$(CONFIG_DIGIC) += digic-uart.o >> +obj-$(CONFIG_STM32F2XX_USART) += stm32f2xx_usart.o >> >> common-obj-$(CONFIG_ETRAXFS) += etraxfs_ser.o >> common-obj-$(CONFIG_ISA_DEBUG) += debugcon.o >> diff --git a/hw/char/stm32f2xx_usart.c b/hw/char/stm32f2xx_usart.c >> new file mode 100644 >> index 0000000..843ff4a >> --- /dev/null >> +++ b/hw/char/stm32f2xx_usart.c >> @@ -0,0 +1,219 @@ >> +/* >> + * STM32F2XX USART >> + * >> + * Copyright (c) 2014 Alistair Francis <alist...@alistair23.me> >> + * >> + * Permission is hereby granted, free of charge, to any person obtaining a >> copy >> + * of this software and associated documentation files (the "Software"), to >> deal >> + * in the Software without restriction, including without limitation the >> rights >> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell >> + * copies of the Software, and to permit persons to whom the Software is >> + * furnished to do so, subject to the following conditions: >> + * >> + * The above copyright notice and this permission notice shall be included >> in >> + * all copies or substantial portions of the Software. >> + * >> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS >> OR >> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, >> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL >> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR >> OTHER >> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING >> FROM, >> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN >> + * THE SOFTWARE. >> + */ >> + >> +#include "hw/char/stm32f2xx_usart.h" >> + >> +#ifndef STM_USART_ERR_DEBUG >> +#define STM_USART_ERR_DEBUG 0 >> +#endif >> + >> +#define DB_PRINT_L(lvl, fmt, args...) do { \ >> + if (STM_USART_ERR_DEBUG >= lvl) { \ >> + qemu_log("%s: " fmt, __func__, ## args); \ >> + } \ >> +} while (0); >> + >> +#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args) >> + >> +static int stm32f2xx_usart_can_receive(void *opaque) >> +{ >> + STM32F2XXUsartState *s = opaque; >> + >> + if (!(s->usart_sr & USART_SR_RXNE)) { >> + return 1; >> + } >> + >> + return 0; >> +} >> + >> +static void stm32f2xx_usart_receive(void *opaque, const uint8_t *buf, int >> size) >> +{ >> + STM32F2XXUsartState *s = opaque; >> + >> + s->usart_dr = *buf; >> + >> + if (!(s->usart_cr1 & USART_CR1_UE && s->usart_cr1 & USART_CR1_RE)) { >> + /* USART not enabled - drop the chars */ >> + DB_PRINT("Dropping the chars\n"); >> + return; >> + } >> + >> + s->usart_sr |= USART_SR_RXNE; >> + >> + if (s->usart_cr1 & USART_CR1_RXNEIE) { >> + qemu_set_irq(s->irq, 1); >> + } >> + >> + DB_PRINT("Receiving: %c\n", s->usart_dr); >> +} >> + >> +static void stm32f2xx_usart_reset(DeviceState *dev) >> +{ >> + STM32F2XXUsartState *s = STM32F2XX_USART(dev); >> + >> + s->usart_sr = USART_SR_RESET; >> + s->usart_dr = 0x00000000; >> + s->usart_brr = 0x00000000; >> + s->usart_cr1 = 0x00000000; >> + s->usart_cr2 = 0x00000000; >> + s->usart_cr3 = 0x00000000; >> + s->usart_gtpr = 0x00000000; > > Does the interrupt lower on a reset?
It doesn't specify that it does, but I assume it will > >> +} >> + >> +static uint64_t stm32f2xx_usart_read(void *opaque, hwaddr addr, >> + unsigned int size) >> +{ >> + STM32F2XXUsartState *s = opaque; >> + uint64_t retvalue; >> + >> + DB_PRINT("Read 0x%"HWADDR_PRIx"\n", addr); >> + >> + switch (addr) { >> + case USART_SR: >> + retvalue = s->usart_sr; >> + s->usart_sr &= ~USART_SR_TC; >> + if (s->chr) { >> + qemu_chr_accept_input(s->chr); >> + } >> + return retvalue; >> + case USART_DR: >> + DB_PRINT("Value: 0x%" PRIx32 ", %c\n", s->usart_dr, (char) >> s->usart_dr); >> + s->usart_sr |= USART_SR_TXE; > > How does a read of the data register affect the TX data-path? > To quote the reference manual: "This bit is set by hardware when the content of the TDR register has been transferred into the shift register.... It is cleared by a write to the USART_DR register." So I just set it there because it has to be set somewhere, and I figured that was the easiest/best place. It also works with code written for the hardware. If you can think of anywhere better I am happy to change it. >> + s->usart_sr &= ~USART_SR_RXNE; >> + if (s->chr) { >> + qemu_chr_accept_input(s->chr); >> + } >> + return s->usart_dr & 0x3FF; >> + case USART_BRR: >> + return s->usart_brr; >> + case USART_CR1: >> + return s->usart_cr1; >> + case USART_CR2: >> + return s->usart_cr2; >> + case USART_CR3: >> + return s->usart_cr3; >> + case USART_GTPR: >> + return s->usart_gtpr; >> + default: >> + qemu_log_mask(LOG_GUEST_ERROR, >> + "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr); >> + return 0; >> + } >> + >> + return 0; >> +} >> + >> +static void stm32f2xx_usart_write(void *opaque, hwaddr addr, >> + uint64_t val64, unsigned int size) >> +{ >> + STM32F2XXUsartState *s = opaque; >> + uint32_t value = val64; >> + unsigned char ch; >> + >> + DB_PRINT("Write 0x%" PRIx32 ", 0x%"HWADDR_PRIx"\n", value, addr); >> + >> + switch (addr) { >> + case USART_SR: >> + if (value <= 0x3FF) { >> + s->usart_sr = value; >> + } else { >> + s->usart_sr &= value; >> + } > > If you set the interrupt enable bit before RXNE is cleared, should the > interrupt raise here? I'm not sure. I can't find anything that specifies either way, but I'm going to assume yes as they represent it with AND gates. Thanks, Alistair > > Regards, > Peter > >> + return; >> + case USART_DR: >> + if (value < 0xF000) { >> + ch = value; >> + if (s->chr) { >> + qemu_chr_fe_write_all(s->chr, &ch, 1); >> + } >> + s->usart_sr |= USART_SR_TC; >> + s->usart_sr &= ~USART_SR_TXE; >> + } >> + return; >> + case USART_BRR: >> + s->usart_brr = value; >> + return; >> + case USART_CR1: >> + s->usart_cr1 = value; >> + return; >> + case USART_CR2: >> + s->usart_cr2 = value; >> + return; >> + case USART_CR3: >> + s->usart_cr3 = value; >> + return; >> + case USART_GTPR: >> + s->usart_gtpr = value; >> + return; >> + default: >> + qemu_log_mask(LOG_GUEST_ERROR, >> + "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr); >> + } >> +} >> + >> +static const MemoryRegionOps stm32f2xx_usart_ops = { >> + .read = stm32f2xx_usart_read, >> + .write = stm32f2xx_usart_write, >> + .endianness = DEVICE_NATIVE_ENDIAN, >> +}; >> + >> +static void stm32f2xx_usart_init(Object *obj) >> +{ >> + STM32F2XXUsartState *s = STM32F2XX_USART(obj); >> + >> + sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irq); >> + >> + memory_region_init_io(&s->mmio, obj, &stm32f2xx_usart_ops, s, >> + TYPE_STM32F2XX_USART, 0x2000); >> + sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio); >> + >> + s->chr = qemu_char_get_next_serial(); >> + >> + if (s->chr) { >> + qemu_chr_add_handlers(s->chr, stm32f2xx_usart_can_receive, >> + stm32f2xx_usart_receive, NULL, s); >> + } >> +} >> + >> +static void stm32f2xx_usart_class_init(ObjectClass *klass, void *data) >> +{ >> + DeviceClass *dc = DEVICE_CLASS(klass); >> + >> + dc->reset = stm32f2xx_usart_reset; >> +} >> + >> +static const TypeInfo stm32f2xx_usart_info = { >> + .name = TYPE_STM32F2XX_USART, >> + .parent = TYPE_SYS_BUS_DEVICE, >> + .instance_size = sizeof(STM32F2XXUsartState), >> + .instance_init = stm32f2xx_usart_init, >> + .class_init = stm32f2xx_usart_class_init, >> +}; >> + >> +static void stm32f2xx_usart_register_types(void) >> +{ >> + type_register_static(&stm32f2xx_usart_info); >> +} >> + >> +type_init(stm32f2xx_usart_register_types) >> diff --git a/include/hw/char/stm32f2xx_usart.h >> b/include/hw/char/stm32f2xx_usart.h >> new file mode 100644 >> index 0000000..c9fad3c >> --- /dev/null >> +++ b/include/hw/char/stm32f2xx_usart.h >> @@ -0,0 +1,69 @@ >> +/* >> + * STM32F2XX USART >> + * >> + * Copyright (c) 2014 Alistair Francis <alist...@alistair23.me> >> + * >> + * Permission is hereby granted, free of charge, to any person obtaining a >> copy >> + * of this software and associated documentation files (the "Software"), to >> deal >> + * in the Software without restriction, including without limitation the >> rights >> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell >> + * copies of the Software, and to permit persons to whom the Software is >> + * furnished to do so, subject to the following conditions: >> + * >> + * The above copyright notice and this permission notice shall be included >> in >> + * all copies or substantial portions of the Software. >> + * >> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS >> OR >> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, >> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL >> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR >> OTHER >> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING >> FROM, >> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN >> + * THE SOFTWARE. >> + */ >> + >> +#include "hw/sysbus.h" >> +#include "sysemu/char.h" >> +#include "hw/hw.h" >> + >> +#define USART_SR 0x00 >> +#define USART_DR 0x04 >> +#define USART_BRR 0x08 >> +#define USART_CR1 0x0C >> +#define USART_CR2 0x10 >> +#define USART_CR3 0x14 >> +#define USART_GTPR 0x18 >> + >> +#define USART_SR_RESET 0x00C00000 >> + >> +#define USART_SR_TXE (1 << 7) >> +#define USART_SR_TC (1 << 6) >> +#define USART_SR_RXNE (1 << 5) >> + >> +#define USART_CR1_UE (1 << 13) >> +#define USART_CR1_RXNEIE (1 << 5) >> +#define USART_CR1_TE (1 << 3) >> +#define USART_CR1_RE (1 << 2) >> + >> +#define TYPE_STM32F2XX_USART "stm32f2xx-usart" >> +#define STM32F2XX_USART(obj) \ >> + OBJECT_CHECK(STM32F2XXUsartState, (obj), TYPE_STM32F2XX_USART) >> + >> +typedef struct { >> + /* <private> */ >> + SysBusDevice parent_obj; >> + >> + /* <public> */ >> + MemoryRegion mmio; >> + >> + uint32_t usart_sr; >> + uint32_t usart_dr; >> + uint32_t usart_brr; >> + uint32_t usart_cr1; >> + uint32_t usart_cr2; >> + uint32_t usart_cr3; >> + uint32_t usart_gtpr; >> + >> + CharDriverState *chr; >> + qemu_irq irq; >> +} STM32F2XXUsartState; >> -- >> 2.1.0 >> >>