From: "zhichang.yuan" <yuanzhich...@hisilicon.com> On Hip06 platform, a 16550 compatible UART is connected to low-pin-count and controlled through the LPC I/O cycles. After registering the LPC uart specific serial_in/serial_out to 8250 core driver, serial data can be read/written through the LPC.
Signed-off-by: zhichang.yuan <yuanzhich...@hisilicon.com> --- .../devicetree/bindings/serial/hisi-lpc-uart.txt | 60 ++++++++ drivers/tty/serial/8250/8250_hisi_lpc.c | 171 +++++++++++++++++++++ drivers/tty/serial/8250/Kconfig | 9 ++ drivers/tty/serial/8250/Makefile | 1 + 4 files changed, 241 insertions(+) create mode 100644 Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt create mode 100644 drivers/tty/serial/8250/8250_hisi_lpc.c diff --git a/Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt b/Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt new file mode 100644 index 0000000..0f8ec2a --- /dev/null +++ b/Documentation/devicetree/bindings/serial/hisi-lpc-uart.txt @@ -0,0 +1,60 @@ +* Hisilicon hip06 UART through low-pin-count + +Required properties: +- compatible : "hisilicon,lpc-uart" +- reg : offset and length of the I/O port set for the device. +- reg-names : name the uart resources. + "lpc_mem" represents memory resource of the LPC parent. When + flat-tree earlycon is needed, this memory resource and + resource name are mandatory. Otherwise they are optional; + "dev_io" represents I/O resource of this device. It is + mandatory to access this device; + +Clock handling: + The clock rate of this device is same as the 8250 default clock rate, that + is 1843200. No need to define the clock rate in device tree. + +Note: + This device depends on its parent device whose compatible string is + "hisilicon,low-pin-count". + + The format of "reg" property follows the I/O space definition in ISA/EISA + binding specification linked to: + http://www.firmware.org/1275/bindings/isa/isa0_4d.ps + +Example: + + uart0: lpc-uart@2f8 { + compatible = "hisilicon,lpc-uart"; + reg = <0x01 0x2f8 0x08>; + status = "disabled"; + }; + + +Example with low-pin-count parent device: + + isa@a01b0000 { + compatible = "hisilicon,low-pin-count"; + #address-cells = <2>; + #size-cells = <1>; + reg = <0x0 0xa01b0000 0x0 0x1000>; + ranges = <0x00 0xa01b0000 0x00 0xa01b0000 0x1000>, + <0x01 0xe4 0x0 0xe4 0x04>, + <0x01 0x2f8 0x0 0x2f8 0x08>; + + ipmi0: bt@e4 { + compatible = "ipmi-bt"; + device_type = "ipmi"; + reg = <0x01 0xe4 0x04>; + reg-names = "dev_io"; + status = "disabled"; + }; + + uart0: lpc-uart@2f8 { + compatible = "hisilicon,lpc-uart"; + reg = <0x00 0xa01b0000 0x1000>, + <0x01 0x2f8 0x08>; + ret-names = "lpc_mem", "dev_io"; + status = "disabled"; + }; + }; diff --git a/drivers/tty/serial/8250/8250_hisi_lpc.c b/drivers/tty/serial/8250/8250_hisi_lpc.c new file mode 100644 index 0000000..a8ba1ca --- /dev/null +++ b/drivers/tty/serial/8250/8250_hisi_lpc.c @@ -0,0 +1,171 @@ +/* + * Copyright (C) 2016 Hisilicon Limited, All Rights Reserved. + * Author: Zhichang Yuan <yuanzhich...@hisilicon.com> + * Author: Zou Rongrong <@huawei.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/module.h> +#include <linux/acpi.h> +#include <linux/serial_8250.h> +#include <asm-generic/serial.h> +#include <linux/of_address.h> + + +/** + * hisilpc_serial_inb - read/input data from the designated serial port. + * @p: the serial port where the data read from + * @offset: the target I/O port address where the read is from + * + * Returns the byte data from this serial port. + * -1 means some failures. + * + */ +static unsigned int hisilpc_serial_inb(struct uart_port *p, int offset) +{ + struct extio_ops *parentops; + + parentops = p->private_data; + if (!parentops || !parentops->pfin) + return -1; + + return parentops->pfin(parentops->devpara, + p->iobase + (offset << p->regshift), + NULL, sizeof(u8), 1); +} + +/** + * hisilpc_serial_outb - write/output data from the designated serial port. + * @p: the serial port where the data is written to + * @offset: the target I/O port address where the write is from + * + */ +static void hisilpc_serial_outb(struct uart_port *p, int offset, int value) +{ + struct extio_ops *parentops; + + parentops = p->private_data; + if (!parentops || !parentops->pfout) + return; + + parentops->pfout(parentops->devpara, + p->iobase + (offset << p->regshift), + &value, sizeof(u8), 1); +} + + +static int hisilpc8250_probe(struct platform_device *pdev) +{ + struct uart_8250_port uart = {}; + struct uart_port *port = &uart.port; + int err = 0; + struct resource *iores; + struct extio_ops *platdata; + + if (!pdev->dev.parent) + return -ENODEV; + dev_info(&pdev->dev, "##probe entering\n"); + + /* To support the earlycon in bootargs, the first reg must be MEM */ + iores = platform_get_resource_byname(pdev, IORESOURCE_IO, + "dev_io"); + if (!iores) { + dev_err(&pdev->dev, "can not find the IO0\n"); + return -ENXIO; + } + + /* + * save the platform data from parent in uart_port for serial_in, + * serial_out + */ + platdata = dev_get_platdata(&pdev->dev); + port->private_data = (void *)platdata; + if (!port->private_data) { + dev_err(&pdev->dev, "no platform data!\n"); + return -ENODEV; + } + + if (platdata->start != iores->start || platdata->end != iores->end) { + dev_err(&pdev->dev, "PIO range[0x%lx - %lx] isn't fit!\n", + (unsigned long)iores->start, + (unsigned long)iores->end); + return -ENXIO; + } + port->iobase = (unsigned long)iores->start + platdata->ptoffset; + dev_info(&pdev->dev, "real port start is 0x%lx\n", port->iobase); + + port->irq = 0; + port->flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT; + port->dev = &pdev->dev; + port->iotype = UPIO_PORT; + port->regshift = 0; + port->uartclk = BASE_BAUD * 16; + + spin_lock_init(&port->lock); + + port->serial_in = hisilpc_serial_inb; + port->serial_out = hisilpc_serial_outb; + + err = serial8250_register_8250_port(&uart); + if (err < 0) { + dev_err(&pdev->dev, "register uart FAIL(%d)!\n", -err); + return err; + } + + platform_set_drvdata(pdev, (void *)&err); + dev_info(&pdev->dev, "##probing OK(%d)\n", err); + return 0; +} + +static int hisilpc8250_remove(struct platform_device *pdev) +{ + int line = *((int *)platform_get_drvdata(pdev)); + + serial8250_unregister_port(line); + + return 0; +} + + +static const struct of_device_id hs8250_of_match[] = { + { .compatible = "hisilicon,lpc-uart" }, + { } +}; +MODULE_DEVICE_TABLE(of, hs8250_of_match); + +static const struct acpi_device_id hs8250_acpi_match[] = { + /*{ "PNP0501", 0 },*/ + { "HISI1031", 0 }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, hs8250_acpi_match); + +static struct platform_driver hs_lpc8250_driver = { + .driver = { + .name = "hisi-lpc-uart", + .of_match_table = hs8250_of_match, + .acpi_match_table = ACPI_PTR(hs8250_acpi_match), + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, + .probe = hisilpc8250_probe, + .remove = hisilpc8250_remove, +}; + +module_platform_driver(hs_lpc8250_driver); + + +MODULE_AUTHOR("Rongrong Zou"); +MODULE_DESCRIPTION("8250 serial probe module for Hisilicon LPC UART"); +MODULE_LICENSE("GPL"); +MODULE_VERSION("v1.0"); diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index 7c6f7af..c2e42f7 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -246,6 +246,15 @@ config SERIAL_8250_HUB6 To compile this driver as a module, choose M here: the module will be called 8250_hub6. +config SERIAL_8250_HISI_LPC + tristate "Support Hisilicon Hip0X UART through LPC" + depends on SERIAL_8250 !=n && HISILICON_LPC + help + Say Y here if you have a hip06 board. + + To compile this driver as a module, choose M here: the module + will be called 8250_hisi_lpc. + # # Misc. options/drivers. # diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile index 367d403..1f2915b 100644 --- a/drivers/tty/serial/8250/Makefile +++ b/drivers/tty/serial/8250/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_SERIAL_8250_BOCA) += 8250_boca.o obj-$(CONFIG_SERIAL_8250_EXAR_ST16C554) += 8250_exar_st16c554.o obj-$(CONFIG_SERIAL_8250_HUB6) += 8250_hub6.o obj-$(CONFIG_SERIAL_8250_FSL) += 8250_fsl.o +obj-$(CONFIG_SERIAL_8250_HISI_LPC) += 8250_hisi_lpc.o obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o obj-$(CONFIG_SERIAL_8250_EM) += 8250_em.o obj-$(CONFIG_SERIAL_8250_OMAP) += 8250_omap.o -- 1.9.1
