From 14a8d47d4e9f51372996914c16bdbf1c34e209b5 Mon Sep 17 00:00:00 2001 From: Jamie Iles Date: Tue, 16 Aug 2011 17:47:47 +0100 Subject: tty: of_serial: add support for the DesignWare 8250 Support the DesignWare 8250 by a new compatible string and registering the DesignWare helpers. If the registration of the helpers fails, then continue as a normal 8250 as we may still get some useful debug out. Cc: Alan Cox Cc: Arnd Bergmann Signed-off-by: Jamie Iles Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/tty/serial/of-serial.txt | 1 + 1 file changed, 1 insertion(+) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/tty/serial/of-serial.txt b/Documentation/devicetree/bindings/tty/serial/of-serial.txt index b8b27b0aca1..b7ceaaa7602 100644 --- a/Documentation/devicetree/bindings/tty/serial/of-serial.txt +++ b/Documentation/devicetree/bindings/tty/serial/of-serial.txt @@ -3,6 +3,7 @@ Required properties: - compatible : one of: - "ns8250" + - "ns8250dw" - "ns16450" - "ns16550a" - "ns16550" -- cgit v1.2.3-70-g09d2 From 0b37004dd0113db3b23840b4fd8835dae2395acc Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Wed, 24 Aug 2011 15:24:54 -0700 Subject: Revert "tty: of_serial: add support for the DesignWare 8250" This reverts commit 14a8d47d4e9f51372996914c16bdbf1c34e209b5. It causes a build error that needs to be resolved differently. Cc: Alan Cox Cc: Arnd Bergmann Cc: Jamie Iles Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/tty/serial/of-serial.txt | 1 - drivers/tty/serial/of_serial.c | 7 ------- 2 files changed, 8 deletions(-) (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/tty/serial/of-serial.txt b/Documentation/devicetree/bindings/tty/serial/of-serial.txt index b7ceaaa7602..b8b27b0aca1 100644 --- a/Documentation/devicetree/bindings/tty/serial/of-serial.txt +++ b/Documentation/devicetree/bindings/tty/serial/of-serial.txt @@ -3,7 +3,6 @@ Required properties: - compatible : one of: - "ns8250" - - "ns8250dw" - "ns16450" - "ns16550a" - "ns16550" diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c index 024926c3be5..e58cece6f44 100644 --- a/drivers/tty/serial/of_serial.c +++ b/drivers/tty/serial/of_serial.c @@ -78,12 +78,6 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev, } } - if (of_device_is_compatible(np, "ns8250dw")) { - ret = serial8250_use_designware_io(port); - if (ret) - dev_warn(&ofdev->dev, "unable to register DesignWare 8250 helpers, continuing as a normal 8250\n"); - } - port->type = type; port->uartclk = clk; port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP @@ -182,7 +176,6 @@ static int of_platform_serial_remove(struct platform_device *ofdev) */ static struct of_device_id __devinitdata of_platform_serial_table[] = { { .compatible = "ns8250", .data = (void *)PORT_8250, }, - { .compatible = "ns8250dw", .data = (void *)PORT_8250, }, { .compatible = "ns16450", .data = (void *)PORT_16450, }, { .compatible = "ns16550a", .data = (void *)PORT_16550A, }, { .compatible = "ns16550", .data = (void *)PORT_16550, }, -- cgit v1.2.3-70-g09d2 From 7d4008ebb1c971ce4baf57e45993690b0fa6d9f9 Mon Sep 17 00:00:00 2001 From: Jamie Iles Date: Fri, 26 Aug 2011 19:04:50 +0100 Subject: tty: add a DesignWare 8250 driver The Synopsys DesignWare 8250 is an 8250 that has an extra interrupt that gets raised when writing to the LCR when busy. To handle this we need special serial_out, serial_in and handle_irq methods. Add a new platform driver that uses these accessors. Cc: Alan Cox Cc: Arnd Bergmann Signed-off-by: Jamie Iles Signed-off-by: Greg Kroah-Hartman --- .../bindings/tty/serial/snps-dw-apb-uart.txt | 25 +++ drivers/tty/serial/8250_dw.c | 194 +++++++++++++++++++++ drivers/tty/serial/Kconfig | 7 + drivers/tty/serial/Makefile | 1 + 4 files changed, 227 insertions(+) create mode 100644 Documentation/devicetree/bindings/tty/serial/snps-dw-apb-uart.txt create mode 100644 drivers/tty/serial/8250_dw.c (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/tty/serial/snps-dw-apb-uart.txt b/Documentation/devicetree/bindings/tty/serial/snps-dw-apb-uart.txt new file mode 100644 index 00000000000..f13f1c5be91 --- /dev/null +++ b/Documentation/devicetree/bindings/tty/serial/snps-dw-apb-uart.txt @@ -0,0 +1,25 @@ +* Synopsys DesignWare ABP UART + +Required properties: +- compatible : "snps,dw-apb-uart" +- reg : offset and length of the register set for the device. +- interrupts : should contain uart interrupt. +- clock-frequency : the input clock frequency for the UART. + +Optional properties: +- reg-shift : quantity to shift the register offsets by. If this property is + not present then the register offsets are not shifted. +- reg-io-width : the size (in bytes) of the IO accesses that should be + performed on the device. If this property is not present then single byte + accesses are used. + +Example: + + uart@80230000 { + compatible = "snps,dw-apb-uart"; + reg = <0x80230000 0x100>; + clock-frequency = <3686400>; + interrupts = <10>; + reg-shift = <2>; + reg-io-width = <4>; + }; diff --git a/drivers/tty/serial/8250_dw.c b/drivers/tty/serial/8250_dw.c new file mode 100644 index 00000000000..bf1fba640c2 --- /dev/null +++ b/drivers/tty/serial/8250_dw.c @@ -0,0 +1,194 @@ +/* + * Synopsys DesignWare 8250 driver. + * + * Copyright 2011 Picochip, Jamie Iles. + * + * 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. + * + * The Synopsys DesignWare 8250 has an extra feature whereby it detects if the + * LCR is written whilst busy. If it is, then a busy detect interrupt is + * raised, the LCR needs to be rewritten and the uart status register read. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct dw8250_data { + int last_lcr; + int line; +}; + +static void dw8250_serial_out(struct uart_port *p, int offset, int value) +{ + struct dw8250_data *d = p->private_data; + + if (offset == UART_LCR) + d->last_lcr = value; + + offset <<= p->regshift; + writeb(value, p->membase + offset); +} + +static unsigned int dw8250_serial_in(struct uart_port *p, int offset) +{ + offset <<= p->regshift; + + return readb(p->membase + offset); +} + +static void dw8250_serial_out32(struct uart_port *p, int offset, int value) +{ + struct dw8250_data *d = p->private_data; + + if (offset == UART_LCR) + d->last_lcr = value; + + offset <<= p->regshift; + writel(value, p->membase + offset); +} + +static unsigned int dw8250_serial_in32(struct uart_port *p, int offset) +{ + offset <<= p->regshift; + + return readl(p->membase + offset); +} + +/* Offset for the DesignWare's UART Status Register. */ +#define UART_USR 0x1f + +static int dw8250_handle_irq(struct uart_port *p) +{ + struct dw8250_data *d = p->private_data; + unsigned int iir = p->serial_in(p, UART_IIR); + + if (serial8250_handle_irq(p, iir)) { + return 1; + } else if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY) { + /* Clear the USR and write the LCR again. */ + (void)p->serial_in(p, UART_USR); + p->serial_out(p, d->last_lcr, UART_LCR); + + return 1; + } + + return 0; +} + +static int __devinit dw8250_probe(struct platform_device *pdev) +{ + struct uart_port port = {}; + struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); + struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + struct device_node *np = pdev->dev.of_node; + u32 val; + struct dw8250_data *data; + + if (!regs || !irq) { + dev_err(&pdev->dev, "no registers/irq defined\n"); + return -EINVAL; + } + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + port.private_data = data; + + spin_lock_init(&port.lock); + port.mapbase = regs->start; + port.irq = irq->start; + port.handle_irq = dw8250_handle_irq; + port.type = PORT_8250; + port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP | + UPF_FIXED_PORT | UPF_FIXED_TYPE; + port.dev = &pdev->dev; + + port.iotype = UPIO_MEM; + port.serial_in = dw8250_serial_in; + port.serial_out = dw8250_serial_out; + if (!of_property_read_u32(np, "reg-io-width", &val)) { + switch (val) { + case 1: + break; + case 4: + port.iotype = UPIO_MEM32; + port.serial_in = dw8250_serial_in32; + port.serial_out = dw8250_serial_out32; + break; + default: + dev_err(&pdev->dev, "unsupported reg-io-width (%u)\n", + val); + return -EINVAL; + } + } + + if (!of_property_read_u32(np, "reg-shift", &val)) + port.regshift = val; + + if (of_property_read_u32(np, "clock-frequency", &val)) { + dev_err(&pdev->dev, "no clock-frequency property set\n"); + return -EINVAL; + } + port.uartclk = val; + + data->line = serial8250_register_port(&port); + if (data->line < 0) + return data->line; + + platform_set_drvdata(pdev, data); + + return 0; +} + +static int __devexit dw8250_remove(struct platform_device *pdev) +{ + struct dw8250_data *data = platform_get_drvdata(pdev); + + serial8250_unregister_port(data->line); + + return 0; +} + +static const struct of_device_id dw8250_match[] = { + { .compatible = "snps,dw-apb-uart" }, + { /* Sentinel */ } +}; +MODULE_DEVICE_TABLE(of, dw8250_match); + +static struct platform_driver dw8250_platform_driver = { + .driver = { + .name = "dw-apb-uart", + .owner = THIS_MODULE, + .of_match_table = dw8250_match, + }, + .probe = dw8250_probe, + .remove = __devexit_p(dw8250_remove), +}; + +static int __init dw8250_init(void) +{ + return platform_driver_register(&dw8250_platform_driver); +} +module_init(dw8250_init); + +static void __exit dw8250_exit(void) +{ + platform_driver_unregister(&dw8250_platform_driver); +} +module_exit(dw8250_exit); + +MODULE_AUTHOR("Jamie Iles"); +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("Synopsys DesignWare 8250 serial port driver"); diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 10babe254e5..8ee3a6626ce 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -267,6 +267,13 @@ config SERIAL_8250_RM9K port hardware found on MIPS RM9122 and similar processors. If unsure, say N. +config SERIAL_8250_DW + tristate "Support for Synopsys DesignWare 8250 quirks" + depends on SERIAL_8250 && OF + help + Selecting this option will enable handling of the extra features + present in the Synopsys DesignWare APB UART. + comment "Non-8250 serial port support" config SERIAL_AMBA_PL010 diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 78748136ccc..7b59958f50e 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -28,6 +28,7 @@ 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_MCA) += 8250_mca.o +obj-$(CONFIG_SERIAL_8250_DW) += 8250_dw.o obj-$(CONFIG_SERIAL_AMBA_PL010) += amba-pl010.o obj-$(CONFIG_SERIAL_AMBA_PL011) += amba-pl011.o obj-$(CONFIG_SERIAL_CLPS711X) += clps711x.o -- cgit v1.2.3-70-g09d2 From 0331bbf3c6fd9997e5f0d165840229ccfeba6548 Mon Sep 17 00:00:00 2001 From: Nicolas Ferre Date: Wed, 12 Oct 2011 18:06:56 +0200 Subject: tty/serial: RS485 bindings for device tree Generic bindings for RS485 feature included in some UARTs. Those bindings have to be used withing an UART device tree node. Documentation updated to link to the bindings definition. Signed-off-by: Nicolas Ferre Acked-by: Grant Likely Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/serial/rs485.txt | 31 ++++++++++++++++++++++ .../devicetree/bindings/tty/serial/atmel-usart.txt | 27 +++++++++++++++++++ Documentation/serial/serial-rs485.txt | 5 ++++ 3 files changed, 63 insertions(+) create mode 100644 Documentation/devicetree/bindings/serial/rs485.txt create mode 100644 Documentation/devicetree/bindings/tty/serial/atmel-usart.txt (limited to 'Documentation/devicetree') diff --git a/Documentation/devicetree/bindings/serial/rs485.txt b/Documentation/devicetree/bindings/serial/rs485.txt new file mode 100644 index 00000000000..1e753c69fc8 --- /dev/null +++ b/Documentation/devicetree/bindings/serial/rs485.txt @@ -0,0 +1,31 @@ +* RS485 serial communications + +The RTS signal is capable of automatically controlling line direction for +the built-in half-duplex mode. +The properties described hereafter shall be given to a half-duplex capable +UART node. + +Required properties: +- rs485-rts-delay: prop-encoded-array where: + * a is the delay beteween rts signal and beginning of data sent in milliseconds. + it corresponds to the delay before sending data. + * b is the delay between end of data sent and rts signal in milliseconds + it corresponds to the delay after sending data and actual release of the line. + +Optional properties: +- linux,rs485-enabled-at-boot-time: empty property telling to enable the rs485 + feature at boot time. It can be disabled later with proper ioctl. +- rs485-rx-during-tx: empty property that enables the receiving of data even + whilst sending data. + +RS485 example for Atmel USART: + usart0: serial@fff8c000 { + compatible = "atmel,at91sam9260-usart"; + reg = <0xfff8c000 0x4000>; + interrupts = <7>; + atmel,use-dma-rx; + atmel,use-dma-tx; + linux,rs485-enabled-at-boot-time; + rs485-rts-delay = <0 200>; // in milliseconds + }; + diff --git a/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt new file mode 100644 index 00000000000..a49d9a1d4cc --- /dev/null +++ b/Documentation/devicetree/bindings/tty/serial/atmel-usart.txt @@ -0,0 +1,27 @@ +* Atmel Universal Synchronous Asynchronous Receiver/Transmitter (USART) + +Required properties: +- compatible: Should be "atmel,-usart" + The compatible indicated will be the first SoC to support an + additional mode or an USART new feature. +- reg: Should contain registers location and length +- interrupts: Should contain interrupt + +Optional properties: +- atmel,use-dma-rx: use of PDC or DMA for receiving data +- atmel,use-dma-tx: use of PDC or DMA for transmitting data + + compatible description: +- at91rm9200: legacy USART support +- at91sam9260: generic USART implementation for SAM9 SoCs + +Example: + + usart0: serial@fff8c000 { + compatible = "atmel,at91sam9260-usart"; + reg = <0xfff8c000 0x4000>; + interrupts = <7>; + atmel,use-dma-rx; + atmel,use-dma-tx; + }; + diff --git a/Documentation/serial/serial-rs485.txt b/Documentation/serial/serial-rs485.txt index c8878f821d1..079cb3df62c 100644 --- a/Documentation/serial/serial-rs485.txt +++ b/Documentation/serial/serial-rs485.txt @@ -28,6 +28,10 @@ RS485 communications. This data structure is used to set and configure RS485 parameters in the platform data and in ioctls. + The device tree can also provide RS485 boot time parameters (see [2] + for bindings). The driver is in charge of filling this data structure from + the values given by the device tree. + Any driver for devices capable of working both as RS232 and RS485 should provide at least the following ioctls: @@ -121,3 +125,4 @@ 5. REFERENCES [1] include/linux/serial.h + [2] Documentation/devicetree/bindings/serial/rs485.txt -- cgit v1.2.3-70-g09d2