| Message ID | 20170502074543.1380-1-joel@jms.id.au |
|---|---|
| Headers | show |
| Series | drivers: serial: Aspeed VUART driver | expand |
On Tue, May 2, 2017 at 10:45 AM, Joel Stanley <joel@jms.id.au> wrote: > From: Jeremy Kerr <jk@ozlabs.org> > > This change adds a driver for the 16550-based Aspeed virtual UART > device. We use a similar process to the of_serial driver for device > probe, but expose some VUART-specific functions through sysfs too. > > The VUART is 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. > > 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). > > OpenPOWER host firmware doesn't like it when the host-side of the > VUART's FIFO is not drained. This driver only disables host TX discard > mode when the port is in use. We set the VUART enabled bit when we bind > to the device, and clear it on unbind. > > We don't want to do this on open/release, as the host may be using this > bit to configure serial output modes, which is independent of whether > the devices has been opened by BMC userspace. > > Signed-off-by: Jeremy Kerr <jk@ozlabs.org> > Signed-off-by: Joel Stanley <joel@jms.id.au> > Acked-by: Rob Herring <robh@kernel.org> > I have reviewed the driver and found it's quality good, though one minor about IRQ getting is left untouched. Let's Greg or others to decide, from my side FWIW: Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> > --- > v4: > - Reorder if statements > - Remove uncessary comment > > v3: > - remove whitespace in header > - reformat comment > - don't check for reg-io-width property; we don't need any special > accessors for reading/writing bytes > - move file to 8250_aspeed_vuart.c > > v2: > - Use attribute groups and DEVICE_ATTR_RW > - Use platform_get_resource/devm_ioremap_resource > - of_find_property -> of_property_read_bool > - Drop unncessary 0xff mask > - Fix comment style > - Use BIT and GENMASK where pssible > - Move to 8250 directory > - Rename ast -> aspeed to match other Aspeed drivers > - Add documentation of sysfs file > - Add detail to the commit message > > Documentation/ABI/stable/sysfs-driver-aspeed-vuart | 15 + > Documentation/devicetree/bindings/serial/8250.txt | 2 + > drivers/tty/serial/8250/8250_aspeed_vuart.c | 323 +++++++++++++++++++++ > drivers/tty/serial/8250/Kconfig | 10 + > drivers/tty/serial/8250/Makefile | 1 + > 5 files changed, 351 insertions(+) > create mode 100644 Documentation/ABI/stable/sysfs-driver-aspeed-vuart > create mode 100644 drivers/tty/serial/8250/8250_aspeed_vuart.c > > 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 > -- > 2.11.0 > -- With Best Regards, Andy Shevchenko -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, 2017-05-02 at 17:15 +0930, Joel Stanley wrote: > From: Jeremy Kerr <jk@ozlabs.org> > > This change adds a driver for the 16550-based Aspeed virtual UART > device. We use a similar process to the of_serial driver for device > probe, but expose some VUART-specific functions through sysfs too. > > The VUART is 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. > > 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). > > OpenPOWER host firmware doesn't like it when the host-side of the > VUART's FIFO is not drained. This driver only disables host TX discard > mode when the port is in use. We set the VUART enabled bit when we bind > to the device, and clear it on unbind. > > We don't want to do this on open/release, as the host may be using this > bit to configure serial output modes, which is independent of whether > the devices has been opened by BMC userspace. > > Signed-off-by: Jeremy Kerr <jk@ozlabs.org> > Signed-off-by: Joel Stanley <joel@jms.id.au> > Acked-by: Rob Herring <robh@kernel.org> Reviewed-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > --- > v4: > - Reorder if statements > - Remove uncessary comment > > v3: > - remove whitespace in header > - reformat comment > - don't check for reg-io-width property; we don't need any special > accessors for reading/writing bytes > - move file to 8250_aspeed_vuart.c > > v2: > - Use attribute groups and DEVICE_ATTR_RW > - Use platform_get_resource/devm_ioremap_resource > - of_find_property -> of_property_read_bool > - Drop unncessary 0xff mask > - Fix comment style > - Use BIT and GENMASK where pssible > - Move to 8250 directory > - Rename ast -> aspeed to match other Aspeed drivers > - Add documentation of sysfs file > - Add detail to the commit message > > Documentation/ABI/stable/sysfs-driver-aspeed-vuart | 15 + > Documentation/devicetree/bindings/serial/8250.txt | 2 + > drivers/tty/serial/8250/8250_aspeed_vuart.c | 323 +++++++++++++++++++++ > drivers/tty/serial/8250/Kconfig | 10 + > drivers/tty/serial/8250/Makefile | 1 + > 5 files changed, 351 insertions(+) > create mode 100644 Documentation/ABI/stable/sysfs-driver-aspeed-vuart > create mode 100644 drivers/tty/serial/8250/8250_aspeed_vuart.c > > 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 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html