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sys/dev/uart/uart_dev_mu.c
- This file was added.
Property | Old Value | New Value |
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svn:eol-style | null | native \ No newline at end of property |
svn:keywords | null | FreeBSD=%H \ No newline at end of property |
svn:mime-type | null | text/plain \ No newline at end of property |
/*- | |||||
* Copyright (c) 2018 Diane Bruce | |||||
* | |||||
* Redistribution and use in source and binary forms, with or without | |||||
* modification, are permitted provided that the following conditions | |||||
* are met: | |||||
* 1. Redistributions of source code must retain the above copyright | |||||
* notice, this list of conditions and the following disclaimer. | |||||
* 2. Redistributions in binary form must reproduce the above copyright | |||||
* notice, this list of conditions and the following disclaimer in the | |||||
* documentation and/or other materials provided with the distribution. | |||||
* | |||||
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND | |||||
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |||||
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |||||
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |||||
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |||||
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |||||
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |||||
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |||||
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |||||
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |||||
* SUCH DAMAGE. | |||||
*/ | |||||
/* | |||||
* Based on uart_dev_pl011.c | |||||
* Copyright (c) 2012 Semihalf. | |||||
* All rights reserved. | |||||
*/ | |||||
/* | |||||
* The mini Uart has the following features: | |||||
* - 7 or 8 bit operation. | |||||
* - 1 start and 1 stop bit. | |||||
* - No parities. | |||||
* - Break generation. | |||||
* - 8 symbols deep FIFOs for receive and transmit. | |||||
* - SW controlled RTS, SW readable CTS. | |||||
* - Auto flow control with programmable FIFO level. | |||||
* - 16550 like registers. | |||||
* - Baudrate derived from system clock. | |||||
* This is a mini UART and it does NOT have the following capabilities: | |||||
* - Break detection | |||||
* - Framing errors detection. | |||||
* - Parity bit | |||||
* - Receive Time-out interrupt | |||||
* - DCD, DSR, DTR or RI signals. | |||||
* The implemented UART is not a 16650 compatible UART However as far | |||||
* as possible the first 8 control and status registers are laid out | |||||
* like a 16550 UART. All 16550 register bits which are not supported can | |||||
* be written but will be ignored and read back as 0. All control bits | |||||
* for simple UART receive/transmit operations are available. | |||||
*/ | |||||
#include "opt_acpi.h" | |||||
#include "opt_platform.h" | |||||
#include <sys/cdefs.h> | |||||
__FBSDID("$FreeBSD$"); | |||||
#include <sys/param.h> | |||||
#include <sys/systm.h> | |||||
#include <sys/kernel.h> | |||||
#include <sys/bus.h> | |||||
#include <machine/bus.h> | |||||
#include <machine/machdep.h> | |||||
#include <machine/pcpu.h> | |||||
#include <dev/uart/uart.h> | |||||
#include <dev/uart/uart_cpu.h> | |||||
#ifdef FDT | |||||
#include <dev/uart/uart_cpu_fdt.h> | |||||
#include <dev/ofw/ofw_bus.h> | |||||
#endif | |||||
#include <dev/uart/uart_bus.h> | |||||
#include "uart_if.h" | |||||
#ifdef DEV_ACPI | |||||
#include <dev/uart/uart_cpu_acpi.h> | |||||
#include <contrib/dev/acpica/include/acpi.h> | |||||
#include <contrib/dev/acpica/include/accommon.h> | |||||
#include <contrib/dev/acpica/include/actables.h> | |||||
#endif | |||||
andrew: Is this needed? | |||||
dbAuthorUnsubmitted Not Done Inline ActionsI didn't know whether it would be needed or not. As you said, it's only on RPi with no ACPI so I have ripped it out. db: I didn't know whether it would be needed or not. As you said, it's only on RPi with no ACPI so… | |||||
#include <sys/kdb.h> | |||||
#ifdef __aarch64__ | |||||
#define IS_FDT (arm64_bus_method == ARM64_BUS_FDT) | |||||
#elif defined(FDT) | |||||
#define IS_FDT 1 | |||||
#else | |||||
#error Unsupported configuration | |||||
#endif | |||||
andrewUnsubmitted Done Inline ActionsAnd this? andrew: And this? | |||||
dbAuthorUnsubmitted Not Done Inline ActionsNot needed without ACPI support. Tested compile. db: Not needed without ACPI support. Tested compile. | |||||
/* BCM2835 Micro UART registers and masks*/ | |||||
#define AUX_MU_IO_REG 0x00 /* I/O register */ | |||||
/* | |||||
* According to errata bits 1 and 2 are swapped, | |||||
* Also bits 2 and 3 are required to enable interrupts. | |||||
*/ | |||||
#define AUX_MU_IER_REG 0x01 | |||||
#define IER_RXENABLE (1) | |||||
#define IER_TXENABLE (1<<1) | |||||
#define IER_REQUIRED (3<<2) | |||||
#define IER_MASK_ALL (IER_TXENABLE|IER_RXENABLE) | |||||
#define AUX_MU_IIR_REG 0x02 | |||||
#define IIR_READY (1) | |||||
#define IIR_TXREADY (1<<1) | |||||
#define IIR_RXREADY (1<<2) | |||||
#define IIR_CLEAR (3<<1) | |||||
#define AUX_MU_LCR_REG 0x03 | |||||
#define LCR_WLEN7 (0) | |||||
#define LCR_WLEN8 (3) | |||||
#define AUX_MU_MCR_REG 0x04 | |||||
#define AUX_MCR_RTS (1<<1) | |||||
#define AUX_MU_LSR_REG 0x05 | |||||
#define LSR_RXREADY (1) | |||||
#define LSR_OVRRUN (1<<1) | |||||
#define LSR_TXEMPTY (1<<5) | |||||
#define LSR_TXIDLE (1<<6) | |||||
#define AUX_MU_MSR_REG 0x06 | |||||
#define MSR_CTS (1<<5) | |||||
#define AUX_MU_SCRATCH_REG 0x07 | |||||
#define AUX_MU_CNTL_REG 0x08 | |||||
#define CNTL_RXENAB (1) | |||||
#define CNTL_TXENAB (1<<1) | |||||
#define AUX_MU_STAT_REG 0x09 | |||||
#define STAT_TX_SA (1<<1) | |||||
#define STAT_RX_SA (1) | |||||
#define AUX_MU_BAUD_REG 0x0a | |||||
/* | |||||
* FIXME: actual register size is SoC-dependent, we need to handle it | |||||
*/ | |||||
#define __uart_getreg(bas, reg) \ | |||||
bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg)) | |||||
#define __uart_setreg(bas, reg, value) \ | |||||
bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value) | |||||
/* | |||||
* Low-level UART interface. | |||||
*/ | |||||
static int uart_mu_probe(struct uart_bas *bas); | |||||
static void uart_mu_init(struct uart_bas *bas, int, int, int, int); | |||||
static void uart_mu_term(struct uart_bas *bas); | |||||
static void uart_mu_putc(struct uart_bas *bas, int); | |||||
static int uart_mu_rxready(struct uart_bas *bas); | |||||
static int uart_mu_getc(struct uart_bas *bas, struct mtx *); | |||||
static struct uart_ops uart_mu_ops = { | |||||
.probe = uart_mu_probe, | |||||
.init = uart_mu_init, | |||||
.term = uart_mu_term, | |||||
.putc = uart_mu_putc, | |||||
.rxready = uart_mu_rxready, | |||||
.getc = uart_mu_getc, | |||||
}; | |||||
static int | |||||
uart_mu_probe(struct uart_bas *bas) | |||||
{ | |||||
return (0); | |||||
} | |||||
/* | |||||
* According to the docs, the cpu clock is locked to 250Mhz when | |||||
* the micro-uart is used | |||||
*/ | |||||
#define CPU_CLOCK 250000000 | |||||
static void | |||||
uart_mu_param(struct uart_bas *bas, int baudrate, int databits, int stopbits, | |||||
int parity) | |||||
{ | |||||
uint32_t line; | |||||
uint32_t baud; | |||||
/* | |||||
* Zero all settings to make sure | |||||
* UART is disabled and not configured | |||||
*/ | |||||
line = 0x0; | |||||
__uart_setreg(bas, AUX_MU_CNTL_REG, line); | |||||
/* As I know UART is disabled I can setup the line */ | |||||
switch (databits) { | |||||
case 7: | |||||
line |= LCR_WLEN7; | |||||
break; | |||||
case 6: | |||||
case 8: | |||||
default: | |||||
line |= LCR_WLEN8; | |||||
break; | |||||
} | |||||
__uart_setreg(bas, AUX_MU_LCR_REG, line); | |||||
/* See 2.2.1 BCM2835-ARM-Peripherals baudrate */ | |||||
if (baudrate != 0) { | |||||
baud = CPU_CLOCK / (8 * baudrate); | |||||
/* XXX | |||||
* baud = cpu_clock() / (8 * baudrate); | |||||
*/ | |||||
__uart_setreg(bas, AUX_MU_BAUD_REG, ((uint32_t)(baud & 0xFFFF))); | |||||
} | |||||
/* re-enable UART */ | |||||
__uart_setreg(bas, AUX_MU_CNTL_REG, CNTL_RXENAB|CNTL_TXENAB); | |||||
} | |||||
static void | |||||
uart_mu_init(struct uart_bas *bas, int baudrate, int databits, int stopbits, | |||||
int parity) | |||||
{ | |||||
/* Mask all interrupts */ | |||||
__uart_setreg(bas, AUX_MU_IER_REG, 0); | |||||
uart_mu_param(bas, baudrate, databits, stopbits, parity); | |||||
} | |||||
static void | |||||
uart_mu_term(struct uart_bas *bas) | |||||
{ | |||||
} | |||||
static void | |||||
uart_mu_putc(struct uart_bas *bas, int c) | |||||
{ | |||||
/* Wait when TX FIFO full. Push character otherwise. */ | |||||
while ((__uart_getreg(bas, AUX_MU_LSR_REG) & LSR_TXEMPTY) == 0) | |||||
; | |||||
__uart_setreg(bas, AUX_MU_IO_REG, c & 0xff); | |||||
} | |||||
static int | |||||
uart_mu_rxready(struct uart_bas *bas) | |||||
{ | |||||
return ((__uart_getreg(bas, AUX_MU_LSR_REG) & LSR_RXREADY) != 0); | |||||
} | |||||
static int | |||||
uart_mu_getc(struct uart_bas *bas, struct mtx *hwmtx) | |||||
{ | |||||
int c; | |||||
while(!uart_mu_rxready(bas)) | |||||
; | |||||
c = __uart_getreg(bas, AUX_MU_IO_REG) & 0xff; | |||||
return (c); | |||||
} | |||||
/* | |||||
* High-level UART interface. | |||||
*/ | |||||
struct uart_mu_softc { | |||||
struct uart_softc bas; | |||||
uint16_t aux_ier; /* Interrupt mask */ | |||||
}; | |||||
static int uart_mu_bus_attach(struct uart_softc *); | |||||
static int uart_mu_bus_detach(struct uart_softc *); | |||||
static int uart_mu_bus_flush(struct uart_softc *, int); | |||||
static int uart_mu_bus_getsig(struct uart_softc *); | |||||
static int uart_mu_bus_ioctl(struct uart_softc *, int, intptr_t); | |||||
static int uart_mu_bus_ipend(struct uart_softc *); | |||||
static int uart_mu_bus_param(struct uart_softc *, int, int, int, int); | |||||
static int uart_mu_bus_probe(struct uart_softc *); | |||||
static int uart_mu_bus_receive(struct uart_softc *); | |||||
static int uart_mu_bus_setsig(struct uart_softc *, int); | |||||
static int uart_mu_bus_transmit(struct uart_softc *); | |||||
static void uart_mu_bus_grab(struct uart_softc *); | |||||
static void uart_mu_bus_ungrab(struct uart_softc *); | |||||
static kobj_method_t uart_mu_methods[] = { | |||||
KOBJMETHOD(uart_attach, uart_mu_bus_attach), | |||||
KOBJMETHOD(uart_detach, uart_mu_bus_detach), | |||||
KOBJMETHOD(uart_flush, uart_mu_bus_flush), | |||||
KOBJMETHOD(uart_getsig, uart_mu_bus_getsig), | |||||
KOBJMETHOD(uart_ioctl, uart_mu_bus_ioctl), | |||||
KOBJMETHOD(uart_ipend, uart_mu_bus_ipend), | |||||
KOBJMETHOD(uart_param, uart_mu_bus_param), | |||||
KOBJMETHOD(uart_probe, uart_mu_bus_probe), | |||||
KOBJMETHOD(uart_receive, uart_mu_bus_receive), | |||||
KOBJMETHOD(uart_setsig, uart_mu_bus_setsig), | |||||
KOBJMETHOD(uart_transmit, uart_mu_bus_transmit), | |||||
KOBJMETHOD(uart_grab, uart_mu_bus_grab), | |||||
KOBJMETHOD(uart_ungrab, uart_mu_bus_ungrab), | |||||
{ 0, 0 } | |||||
}; | |||||
static struct uart_class uart_mu_class = { | |||||
"aux-uart", | |||||
uart_mu_methods, | |||||
sizeof(struct uart_mu_softc), | |||||
.uc_ops = &uart_mu_ops, | |||||
.uc_range = 0x48, | |||||
.uc_rclk = 0, | |||||
.uc_rshift = 2 | |||||
}; | |||||
#ifdef FDT | |||||
static struct ofw_compat_data fdt_compat_data[] = { | |||||
{"brcm,bcm2835-aux-uart" , (uintptr_t)&uart_mu_class}, | |||||
{NULL, (uintptr_t)NULL}, | |||||
}; | |||||
UART_FDT_CLASS_AND_DEVICE(fdt_compat_data); | |||||
#endif | |||||
/* XXX Where should ACPI_DBG2_ARM_MU go? */ | |||||
#ifdef DEV_ACPI | |||||
static struct acpi_uart_compat_data acpi_compat_data[] = { | |||||
#if 0 | |||||
{"ARMHMU", &uart_mu_class, ACPI_DBG2_ARM_MU}, | |||||
#endif | |||||
{"ARMHMU", &uart_mu_class, ACPI_DBG2_ARM_SBSA_GENERIC}, | |||||
{NULL, NULL, 0}, | |||||
}; | |||||
UART_ACPI_CLASS_AND_DEVICE(acpi_compat_data); | |||||
#endif | |||||
andrewUnsubmitted Done Inline ActionsWe could probably just ignore ACPI support in a RPi only driver andrew: We could probably just ignore ACPI support in a RPi only driver | |||||
dbAuthorUnsubmitted Not Done Inline ActionsAgreed. db: Agreed. | |||||
static int | |||||
uart_mu_bus_attach(struct uart_softc *sc) | |||||
{ | |||||
struct uart_mu_softc *psc; | |||||
struct uart_bas *bas; | |||||
psc = (struct uart_mu_softc *)sc; | |||||
bas = &sc->sc_bas; | |||||
/* Clear interrupts */ | |||||
__uart_setreg(bas, AUX_MU_IIR_REG, IIR_CLEAR); | |||||
/* Enable interrupts */ | |||||
psc->aux_ier = (IER_RXENABLE|IER_TXENABLE|IER_REQUIRED); | |||||
__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier); | |||||
sc->sc_txbusy = 0; | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_detach(struct uart_softc *sc) | |||||
{ | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_flush(struct uart_softc *sc, int what) | |||||
{ | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_getsig(struct uart_softc *sc) | |||||
{ | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_ioctl(struct uart_softc *sc, int request, intptr_t data) | |||||
{ | |||||
struct uart_bas *bas; | |||||
int error; | |||||
bas = &sc->sc_bas; | |||||
error = 0; | |||||
uart_lock(sc->sc_hwmtx); | |||||
switch (request) { | |||||
case UART_IOCTL_BREAK: | |||||
break; | |||||
case UART_IOCTL_BAUD: | |||||
*(int*)data = 115200; | |||||
break; | |||||
default: | |||||
error = EINVAL; | |||||
break; | |||||
} | |||||
uart_unlock(sc->sc_hwmtx); | |||||
return (error); | |||||
} | |||||
static int | |||||
uart_mu_bus_ipend(struct uart_softc *sc) | |||||
{ | |||||
struct uart_mu_softc *psc; | |||||
struct uart_bas *bas; | |||||
uint32_t ints; | |||||
int ipend; | |||||
psc = (struct uart_mu_softc *)sc; | |||||
bas = &sc->sc_bas; | |||||
uart_lock(sc->sc_hwmtx); | |||||
ints = __uart_getreg(bas, AUX_MU_IIR_REG); | |||||
ipend = 0; | |||||
/* | |||||
* According to docs only one of IIR_RXREADY | |||||
* or IIR_TXREADY are valid eg. Only one or the other. | |||||
*/ | |||||
if (ints & IIR_RXREADY) { | |||||
ipend |= SER_INT_RXREADY; | |||||
} else if (ints & IIR_TXREADY) { | |||||
if (__uart_getreg(bas, AUX_MU_LSR_REG) & LSR_TXIDLE) { | |||||
if (sc->sc_txbusy) | |||||
ipend |= SER_INT_TXIDLE; | |||||
/* Disable TX interrupt */ | |||||
__uart_setreg(bas, AUX_MU_IER_REG, | |||||
psc->aux_ier & ~IER_TXENABLE); | |||||
} | |||||
} | |||||
uart_unlock(sc->sc_hwmtx); | |||||
return (ipend); | |||||
} | |||||
static int | |||||
uart_mu_bus_param(struct uart_softc *sc, int baudrate, int databits, | |||||
int stopbits, int parity) | |||||
{ | |||||
uart_lock(sc->sc_hwmtx); | |||||
uart_mu_param(&sc->sc_bas, baudrate, databits, stopbits, parity); | |||||
uart_unlock(sc->sc_hwmtx); | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_probe(struct uart_softc *sc) | |||||
{ | |||||
/* MU always has 8 byte deep fifo */ | |||||
sc->sc_rxfifosz = 8; | |||||
sc->sc_txfifosz = 8; | |||||
device_set_desc(sc->sc_dev, "BCM2835 Mini-UART"); | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_receive(struct uart_softc *sc) | |||||
{ | |||||
struct uart_mu_softc *psc; | |||||
struct uart_bas *bas; | |||||
uint32_t lsr, xc; | |||||
int rx; | |||||
bas = &sc->sc_bas; | |||||
uart_lock(sc->sc_hwmtx); | |||||
psc = (struct uart_mu_softc *)sc; | |||||
lsr = __uart_getreg(bas, AUX_MU_LSR_REG); | |||||
while (lsr & LSR_RXREADY) { | |||||
xc = __uart_getreg(bas, AUX_MU_IO_REG); | |||||
rx = xc & 0xff; | |||||
if (uart_rx_full(sc)) { | |||||
sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN; | |||||
break; | |||||
} | |||||
uart_rx_put(sc, rx); | |||||
lsr = __uart_getreg(bas, AUX_MU_LSR_REG); | |||||
} | |||||
uart_unlock(sc->sc_hwmtx); | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_setsig(struct uart_softc *sc, int sig) | |||||
{ | |||||
return (0); | |||||
} | |||||
static int | |||||
uart_mu_bus_transmit(struct uart_softc *sc) | |||||
{ | |||||
struct uart_mu_softc *psc; | |||||
struct uart_bas *bas; | |||||
int i; | |||||
psc = (struct uart_mu_softc *)sc; | |||||
bas = &sc->sc_bas; | |||||
uart_lock(sc->sc_hwmtx); | |||||
for (i = 0; i < sc->sc_txdatasz; i++) { | |||||
__uart_setreg(bas, AUX_MU_IO_REG, sc->sc_txbuf[i] & 0xff); | |||||
uart_barrier(bas); | |||||
} | |||||
/* Mark busy and enable TX interrupt */ | |||||
sc->sc_txbusy = 1; | |||||
__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier); | |||||
uart_unlock(sc->sc_hwmtx); | |||||
return (0); | |||||
} | |||||
static void | |||||
uart_mu_bus_grab(struct uart_softc *sc) | |||||
{ | |||||
struct uart_mu_softc *psc; | |||||
struct uart_bas *bas; | |||||
psc = (struct uart_mu_softc *)sc; | |||||
bas = &sc->sc_bas; | |||||
/* Disable interrupts on switch to polling */ | |||||
uart_lock(sc->sc_hwmtx); | |||||
__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier &~IER_MASK_ALL); | |||||
uart_unlock(sc->sc_hwmtx); | |||||
} | |||||
static void | |||||
uart_mu_bus_ungrab(struct uart_softc *sc) | |||||
{ | |||||
struct uart_mu_softc *psc; | |||||
struct uart_bas *bas; | |||||
psc = (struct uart_mu_softc *)sc; | |||||
bas = &sc->sc_bas; | |||||
/* Switch to using interrupts while not grabbed */ | |||||
uart_lock(sc->sc_hwmtx); | |||||
__uart_setreg(bas, AUX_MU_CNTL_REG, CNTL_RXENAB|CNTL_TXENAB); | |||||
__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier); | |||||
uart_unlock(sc->sc_hwmtx); | |||||
} |
Is this needed?