diff options
| -rw-r--r-- | Documentation/ABI/stable/sysfs-driver-aspeed-vuart | 15 | ||||
| -rw-r--r-- | Documentation/devicetree/bindings/serial/8250.txt | 2 | ||||
| -rw-r--r-- | drivers/tty/serial/8250/8250_aspeed_vuart.c | 323 | ||||
| -rw-r--r-- | drivers/tty/serial/8250/Kconfig | 10 | ||||
| -rw-r--r-- | drivers/tty/serial/8250/Makefile | 1 |
5 files changed, 351 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-aspeed-vuart b/Documentation/ABI/stable/sysfs-driver-aspeed-vuart new file mode 100644 index 000000000000..8062953ce77b --- /dev/null +++ b/Documentation/ABI/stable/sysfs-driver-aspeed-vuart @@ -0,0 +1,15 @@ +What: /sys/bus/platform/drivers/aspeed-vuart/*/lpc_address +Date: April 2017 +Contact: Jeremy Kerr <jk@ozlabs.org> +Description: Configures which IO port the host side of the UART + will appear on the host <-> BMC LPC bus. +Users: OpenBMC. Proposed changes should be mailed to + openbmc@lists.ozlabs.org + +What: /sys/bus/platform/drivers/aspeed-vuart*/sirq +Date: April 2017 +Contact: Jeremy Kerr <jk@ozlabs.org> +Description: Configures which interrupt number the host side of + the UART will appear on the host <-> BMC LPC bus. +Users: OpenBMC. Proposed changes should be mailed to + openbmc@lists.ozlabs.org diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt index 10276a46ecef..656733949309 100644 --- a/Documentation/devicetree/bindings/serial/8250.txt +++ b/Documentation/devicetree/bindings/serial/8250.txt @@ -20,6 +20,8 @@ Required properties: - "fsl,16550-FIFO64" - "fsl,ns16550" - "ti,da830-uart" + - "aspeed,ast2400-vuart" + - "aspeed,ast2500-vuart" - "serial" if the port type is unknown. - reg : offset and length of the register set for the device. - interrupts : should contain uart interrupt. diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c new file mode 100644 index 000000000000..822be4906763 --- /dev/null +++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c @@ -0,0 +1,323 @@ +/* + * Serial Port driver for Aspeed VUART device + * + * Copyright (C) 2016 Jeremy Kerr <jk@ozlabs.org>, IBM Corp. + * Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ +#include <linux/device.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <linux/of_platform.h> +#include <linux/clk.h> + +#include "8250.h" + +#define ASPEED_VUART_GCRA 0x20 +#define ASPEED_VUART_GCRA_VUART_EN BIT(0) +#define ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD BIT(5) +#define ASPEED_VUART_GCRB 0x24 +#define ASPEED_VUART_GCRB_HOST_SIRQ_MASK GENMASK(7, 4) +#define ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT 4 +#define ASPEED_VUART_ADDRL 0x28 +#define ASPEED_VUART_ADDRH 0x2c + +struct aspeed_vuart { + struct device *dev; + void __iomem *regs; + struct clk *clk; + int line; +}; + +/* + * The VUART is basically two UART 'front ends' connected by their FIFO + * (no actual serial line in between). One is on the BMC side (management + * controller) and one is on the host CPU side. + * + * It allows the BMC to provide to the host a "UART" that pipes into + * the BMC itself and can then be turned by the BMC into a network console + * of some sort for example. + * + * This driver is for the BMC side. The sysfs files allow the BMC + * userspace which owns the system configuration policy, to specify + * at what IO port and interrupt number the host side will appear + * to the host on the Host <-> BMC LPC bus. It could be different on a + * different system (though most of them use 3f8/4). + */ + +static ssize_t lpc_address_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + u16 addr; + + addr = (readb(vuart->regs + ASPEED_VUART_ADDRH) << 8) | + (readb(vuart->regs + ASPEED_VUART_ADDRL)); + + return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr); +} + +static ssize_t lpc_address_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + unsigned long val; + int err; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + writeb(val >> 8, vuart->regs + ASPEED_VUART_ADDRH); + writeb(val >> 0, vuart->regs + ASPEED_VUART_ADDRL); + + return count; +} + +static DEVICE_ATTR_RW(lpc_address); + +static ssize_t sirq_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + u8 reg; + + reg = readb(vuart->regs + ASPEED_VUART_GCRB); + reg &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + reg >>= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT; + + return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg); +} + +static ssize_t sirq_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct aspeed_vuart *vuart = dev_get_drvdata(dev); + unsigned long val; + int err; + u8 reg; + + err = kstrtoul(buf, 0, &val); + if (err) + return err; + + val <<= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT; + val &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + + reg = readb(vuart->regs + ASPEED_VUART_GCRB); + reg &= ~ASPEED_VUART_GCRB_HOST_SIRQ_MASK; + reg |= val; + writeb(reg, vuart->regs + ASPEED_VUART_GCRB); + + return count; +} + +static DEVICE_ATTR_RW(sirq); + +static struct attribute *aspeed_vuart_attrs[] = { + &dev_attr_sirq.attr, + &dev_attr_lpc_address.attr, + NULL, +}; + +static const struct attribute_group aspeed_vuart_attr_group = { + .attrs = aspeed_vuart_attrs, +}; + +static void aspeed_vuart_set_enabled(struct aspeed_vuart *vuart, bool enabled) +{ + u8 reg = readb(vuart->regs + ASPEED_VUART_GCRA); + + if (enabled) + reg |= ASPEED_VUART_GCRA_VUART_EN; + else + reg &= ~ASPEED_VUART_GCRA_VUART_EN; + + writeb(reg, vuart->regs + ASPEED_VUART_GCRA); +} + +static void aspeed_vuart_set_host_tx_discard(struct aspeed_vuart *vuart, + bool discard) +{ + u8 reg; + + reg = readb(vuart->regs + ASPEED_VUART_GCRA); + + /* If the DISABLE_HOST_TX_DISCARD bit is set, discard is disabled */ + if (!discard) + reg |= ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD; + else + reg &= ~ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD; + + writeb(reg, vuart->regs + ASPEED_VUART_GCRA); +} + +static int aspeed_vuart_startup(struct uart_port *uart_port) +{ + struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port); + struct aspeed_vuart *vuart = uart_8250_port->port.private_data; + int rc; + + rc = serial8250_do_startup(uart_port); + if (rc) + return rc; + + aspeed_vuart_set_host_tx_discard(vuart, false); + + return 0; +} + +static void aspeed_vuart_shutdown(struct uart_port *uart_port) +{ + struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port); + struct aspeed_vuart *vuart = uart_8250_port->port.private_data; + + aspeed_vuart_set_host_tx_discard(vuart, true); + + serial8250_do_shutdown(uart_port); +} + +static int aspeed_vuart_probe(struct platform_device *pdev) +{ + struct uart_8250_port port; + struct aspeed_vuart *vuart; + struct device_node *np; + struct resource *res; + u32 clk, prop; + int rc; + + np = pdev->dev.of_node; + + vuart = devm_kzalloc(&pdev->dev, sizeof(*vuart), GFP_KERNEL); + if (!vuart) + return -ENOMEM; + + vuart->dev = &pdev->dev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + vuart->regs = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(vuart->regs)) + return PTR_ERR(vuart->regs); + + memset(&port, 0, sizeof(port)); + port.port.private_data = vuart; + port.port.membase = vuart->regs; + port.port.mapbase = res->start; + port.port.mapsize = resource_size(res); + port.port.startup = aspeed_vuart_startup; + port.port.shutdown = aspeed_vuart_shutdown; + port.port.dev = &pdev->dev; + + rc = sysfs_create_group(&vuart->dev->kobj, &aspeed_vuart_attr_group); + if (rc < 0) + return rc; + + if (of_property_read_u32(np, "clock-frequency", &clk)) { + vuart->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(vuart->clk)) { + dev_warn(&pdev->dev, + "clk or clock-frequency not defined\n"); + return PTR_ERR(vuart->clk); + } + + rc = clk_prepare_enable(vuart->clk); + if (rc < 0) + return rc; + + clk = clk_get_rate(vuart->clk); + } + + /* If current-speed was set, then try not to change it. */ + if (of_property_read_u32(np, "current-speed", &prop) == 0) + port.port.custom_divisor = clk / (16 * prop); + + /* Check for shifted address mapping */ + if (of_property_read_u32(np, "reg-offset", &prop) == 0) + port.port.mapbase += prop; + + /* Check for registers offset within the devices address range */ + if (of_property_read_u32(np, "reg-shift", &prop) == 0) + port.port.regshift = prop; + + /* Check for fifo size */ + if (of_property_read_u32(np, "fifo-size", &prop) == 0) + port.port.fifosize = prop; + + /* Check for a fixed line number */ + rc = of_alias_get_id(np, "serial"); + if (rc >= 0) + port.port.line = rc; + + port.port.irq = irq_of_parse_and_map(np, 0); + port.port.irqflags = IRQF_SHARED; + port.port.iotype = UPIO_MEM; + port.port.type = PORT_16550A; + port.port.uartclk = clk; + port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF + | UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST; + + if (of_property_read_bool(np, "no-loopback-test")) + port.port.flags |= UPF_SKIP_TEST; + + if (port.port.fifosize) + port.capabilities = UART_CAP_FIFO; + + if (of_property_read_bool(np, "auto-flow-control")) + port.capabilities |= UART_CAP_AFE; + + rc = serial8250_register_8250_port(&port); + if (rc < 0) + goto err_clk_disable; + + vuart->line = rc; + + aspeed_vuart_set_enabled(vuart, true); + aspeed_vuart_set_host_tx_discard(vuart, true); + platform_set_drvdata(pdev, vuart); + + return 0; + +err_clk_disable: + clk_disable_unprepare(vuart->clk); + irq_dispose_mapping(port.port.irq); + return rc; +} + +static int aspeed_vuart_remove(struct platform_device *pdev) +{ + struct aspeed_vuart *vuart = platform_get_drvdata(pdev); + + aspeed_vuart_set_enabled(vuart, false); + serial8250_unregister_port(vuart->line); + sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group); + clk_disable_unprepare(vuart->clk); + + return 0; +} + +static const struct of_device_id aspeed_vuart_table[] = { + { .compatible = "aspeed,ast2400-vuart" }, + { .compatible = "aspeed,ast2500-vuart" }, + { }, +}; + +static struct platform_driver aspeed_vuart_driver = { + .driver = { + .name = "aspeed-vuart", + .of_match_table = aspeed_vuart_table, + }, + .probe = aspeed_vuart_probe, + .remove = aspeed_vuart_remove, +}; + +module_platform_driver(aspeed_vuart_driver); + +MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Driver for Aspeed VUART device"); diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig index 0e3f529d50e9..a1161ec0256f 100644 --- a/drivers/tty/serial/8250/Kconfig +++ b/drivers/tty/serial/8250/Kconfig @@ -224,6 +224,16 @@ config SERIAL_8250_ACCENT To compile this driver as a module, choose M here: the module will be called 8250_accent. +config SERIAL_8250_ASPEED_VUART + tristate "Aspeed Virtual UART" + depends on SERIAL_8250 + depends on OF + help + If you want to use the virtual UART (VUART) device on Aspeed + BMC platforms, enable this option. This enables the 16550A- + compatible device on the local LPC bus, giving a UART device + with no physical RS232 connections. + config SERIAL_8250_BOCA tristate "Support Boca cards" depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile index 2f30f9ecdb1b..a44a99a3e623 100644 --- a/drivers/tty/serial/8250/Makefile +++ b/drivers/tty/serial/8250/Makefile @@ -14,6 +14,7 @@ obj-$(CONFIG_SERIAL_8250_EXAR) += 8250_exar.o obj-$(CONFIG_SERIAL_8250_HP300) += 8250_hp300.o obj-$(CONFIG_SERIAL_8250_CS) += serial_cs.o obj-$(CONFIG_SERIAL_8250_ACORN) += 8250_acorn.o +obj-$(CONFIG_SERIAL_8250_ASPEED_VUART) += 8250_aspeed_vuart.o obj-$(CONFIG_SERIAL_8250_BCM2835AUX) += 8250_bcm2835aux.o obj-$(CONFIG_SERIAL_8250_CONSOLE) += 8250_early.o obj-$(CONFIG_SERIAL_8250_FOURPORT) += 8250_fourport.o |