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 --- MAINTAINERS | 1 + drivers/serial/Kconfig | 9 +++++ drivers/serial/Makefile | 1 + drivers/serial/serial_bcm283x_pl011.c | 73 ++++++++++++++++++++++++++++++++++ drivers/serial/serial_pl01x.c | 11 ++--- drivers/serial/serial_pl01x_internal.h | 15 ++++++- 6 files changed, 101 insertions(+), 9 deletions(-) create mode 100644 drivers/serial/serial_bcm283x_pl011.c
diff --git a/MAINTAINERS b/MAINTAINERS index 19f645d825..c614ff2d5c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -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/ diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index 72281a7b64..3ffedba525 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -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 diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 5ef603ab15..cac9a8b312 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -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 diff --git a/drivers/serial/serial_bcm283x_pl011.c b/drivers/serial/serial_bcm283x_pl011.c new file mode 100644 index 0000000000..bfd39f84f3 --- /dev/null +++ b/drivers/serial/serial_bcm283x_pl011.c @@ -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), +}; diff --git a/drivers/serial/serial_pl01x.c b/drivers/serial/serial_pl01x.c index 2cbc84c1b4..23d9d839cb 100644 --- a/drivers/serial/serial_pl01x.c +++ b/drivers/serial/serial_pl01x.c @@ -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; diff --git a/drivers/serial/serial_pl01x_internal.h b/drivers/serial/serial_pl01x_internal.h index 288a4f19f5..c56dd54c7b 100644 --- a/drivers/serial/serial_pl01x_internal.h +++ b/drivers/serial/serial_pl01x_internal.h @@ -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