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bcm2835_pl011_serial: Add BCM2835 specific serial driver

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On bcm2835 we need to ensure we only access serial devices that are
muxed to the serial output pins of the pin header. To achieve this
for the pl011 device, add a bcm2835 specific pl011 wrapper device
that does this check but otherwise behaves like a pl011 device.

Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Alexander Graf 2018-01-25 12:05:55 +01:00 committed by Tom Rini
parent 958d55f26c
commit 6001985f92
6 changed files with 101 additions and 9 deletions
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1
MAINTAINERS
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@ -99,6 +99,7 @@ F: drivers/gpio/bcm2835_gpio.c
F: drivers/mmc/bcm2835_sdhci.c
F: drivers/mmc/bcm2835_sdhost.c
F: drivers/serial/serial_bcm283x_mu.c
F: drivers/serial/serial_bcm283x_pl011.c
F: drivers/video/bcm2835.c
F: include/dm/platform_data/serial_bcm283x_mu.h
F: drivers/pinctrl/broadcom/

9
drivers/serial/Kconfig
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@ -395,6 +395,15 @@ config BCM283X_MU_SERIAL
help
Select this to enable Mini-UART support on BCM283X family of SoCs.
config BCM283X_PL011_SERIAL
bool "Support for BCM283x PL011 UART"
depends on PL01X_SERIAL && ARCH_BCM283X
default y
help
Select this to enable an overriding PL011 driver for BCM283X SoCs
that supports automatic disable, so that it only gets used when
the UART is actually muxed.
config BCM6345_SERIAL
bool "Support for BCM6345 UART"
depends on DM_SERIAL && ARCH_BMIPS

1
drivers/serial/Makefile
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@ -46,6 +46,7 @@ obj-$(CONFIG_STI_ASC_SERIAL) += serial_sti_asc.o
obj-$(CONFIG_PIC32_SERIAL) += serial_pic32.o
obj-$(CONFIG_STM32_SERIAL) += serial_stm32.o
obj-$(CONFIG_BCM283X_MU_SERIAL) += serial_bcm283x_mu.o
obj-$(CONFIG_BCM283X_PL011_SERIAL) += serial_bcm283x_pl011.o
obj-$(CONFIG_MSM_SERIAL) += serial_msm.o
obj-$(CONFIG_MVEBU_A3700_UART) += serial_mvebu_a3700.o
obj-$(CONFIG_MPC8XX_CONS) += serial_mpc8xx.o

73
drivers/serial/serial_bcm283x_pl011.c Normal file
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@ -0,0 +1,73 @@
/*
* Copyright (c) 2018 Alexander Graf <agraf@suse.de>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <asm/gpio.h>
#include <dm/pinctrl.h>
#include <dm/platform_data/serial_pl01x.h>
#include "serial_pl01x_internal.h"
/*
* Check if this serial device is muxed
*
* The serial device will only work properly if it has been muxed to the serial
* pins by firmware. Check whether that happened here.
*
* @return true if serial device is muxed, false if not
*/
static bool bcm283x_is_serial_muxed(void)
{
int serial_gpio = 15;
struct udevice *dev;
if (uclass_first_device(UCLASS_PINCTRL, &dev) || !dev)
return false;
if (pinctrl_get_gpio_mux(dev, 0, serial_gpio) != BCM2835_GPIO_ALT0)
return false;
return true;
}
static int bcm283x_pl011_serial_ofdata_to_platdata(struct udevice *dev)
{
struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
int ret;
/* Don't spawn the device if it's not muxed */
if (!bcm283x_is_serial_muxed())
return -ENODEV;
ret = pl01x_serial_ofdata_to_platdata(dev);
if (ret)
return ret;
/*
* TODO: Reinitialization doesn't always work for now, just skip
* init always - we know we're already initialized
*/
plat->skip_init = true;
return 0;
}
static const struct udevice_id bcm283x_pl011_serial_id[] = {
{.compatible = "brcm,bcm2835-pl011", .data = TYPE_PL011},
{}
};
U_BOOT_DRIVER(bcm283x_pl011_uart) = {
.name = "bcm283x_pl011",
.id = UCLASS_SERIAL,
.of_match = of_match_ptr(bcm283x_pl011_serial_id),
.ofdata_to_platdata = of_match_ptr(bcm283x_pl011_serial_ofdata_to_platdata),
.platdata_auto_alloc_size = sizeof(struct pl01x_serial_platdata),
.probe = pl01x_serial_probe,
.ops = &pl01x_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
.priv_auto_alloc_size = sizeof(struct pl01x_priv),
};

11
drivers/serial/serial_pl01x.c
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@ -273,11 +273,6 @@ __weak struct serial_device *default_serial_console(void)
#ifdef CONFIG_DM_SERIAL
struct pl01x_priv {
struct pl01x_regs *regs;
enum pl01x_type type;
};
static int pl01x_serial_setbrg(struct udevice *dev, int baudrate)
{
struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
@ -291,7 +286,7 @@ static int pl01x_serial_setbrg(struct udevice *dev, int baudrate)
return 0;
}
static int pl01x_serial_probe(struct udevice *dev)
int pl01x_serial_probe(struct udevice *dev)
{
struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
struct pl01x_priv *priv = dev_get_priv(dev);
@ -329,7 +324,7 @@ static int pl01x_serial_pending(struct udevice *dev, bool input)
return fr & UART_PL01x_FR_TXFF ? 0 : 1;
}
static const struct dm_serial_ops pl01x_serial_ops = {
const struct dm_serial_ops pl01x_serial_ops = {
.putc = pl01x_serial_putc,
.pending = pl01x_serial_pending,
.getc = pl01x_serial_getc,
@ -343,7 +338,7 @@ static const struct udevice_id pl01x_serial_id[] ={
{}
};
static int pl01x_serial_ofdata_to_platdata(struct udevice *dev)
int pl01x_serial_ofdata_to_platdata(struct udevice *dev)
{
struct pl01x_serial_platdata *plat = dev_get_platdata(dev);
fdt_addr_t addr;

15
drivers/serial/serial_pl01x_internal.h
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@ -38,7 +38,20 @@ struct pl01x_regs {
u32 pl011_lcrh; /* 0x2C Line control register */
u32 pl011_cr; /* 0x30 Control register */
};
#endif
#ifdef CONFIG_DM_SERIAL
int pl01x_serial_ofdata_to_platdata(struct udevice *dev);
int pl01x_serial_probe(struct udevice *dev);
extern const struct dm_serial_ops pl01x_serial_ops;
struct pl01x_priv {
struct pl01x_regs *regs;
enum pl01x_type type;
};
#endif /* CONFIG_DM_SERIAL */
#endif /* !__ASSEMBLY__ */
#define UART_PL01x_RSR_OE 0x08
#define UART_PL01x_RSR_BE 0x04