[PATCH] serial uartlite driver (238b8721) · Commits · e / devices / android_kernel_oneplus_sm7250

MAINTAINERS

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		@@ -3454,6 +3454,12 @@ W: http://oss.sgi.com/projects/xfs
		T: git git://oss.sgi.com:8090/xfs/xfs-2.6
		S: Supported

		XILINX UARTLITE SERIAL DRIVER
		P: Peter Korsgaard
		M: jacmet@sunsite.dk
		L: linux-serial@vger.kernel.org
		S: Maintained

		X86 3-LEVEL PAGING (PAE) SUPPORT
		P: Ingo Molnar
		M: mingo@redhat.com

drivers/serial/Kconfig

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		@@ -511,6 +511,25 @@ config SERIAL_IMX_CONSOLE
		your boot loader (lilo or loadlin) about how to pass options to the
		kernel at boot time.)

		config SERIAL_UARTLITE
		tristate "Xilinx uartlite serial port support"
		depends on PPC32
		select SERIAL_CORE
		help
		Say Y here if you want to use the Xilinx uartlite serial controller.

		To compile this driver as a module, choose M here: the
		module will be called uartlite.ko.

		config SERIAL_UARTLITE_CONSOLE
		bool "Support for console on Xilinx uartlite serial port"
		depends on SERIAL_UARTLITE=y
		select SERIAL_CORE_CONSOLE
		help
		Say Y here if you wish to use a Xilinx uartlite as the system
		console (the system console is the device which receives all kernel
		messages and warnings and which allows logins in single user mode).

		config SERIAL_SUNCORE
		bool
		depends on SPARC

drivers/serial/Makefile

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		@@ -55,4 +55,5 @@ obj-$(CONFIG_SERIAL_VR41XX) += vr41xx_siu.o
		obj-$(CONFIG_SERIAL_SGI_IOC4) += ioc4_serial.o
		obj-$(CONFIG_SERIAL_SGI_IOC3) += ioc3_serial.o
		obj-$(CONFIG_SERIAL_ATMEL) += atmel_serial.o
		obj-$(CONFIG_SERIAL_UARTLITE) += uartlite.o
		obj-$(CONFIG_SERIAL_NETX) += netx-serial.o

drivers/serial/uartlite.c

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		/*
		* uartlite.c: Serial driver for Xilinx uartlite serial controller
		*
		* Peter Korsgaard <jacmet@sunsite.dk>
		*
		* This file is licensed under the terms of the GNU General Public License
		* version 2. This program is licensed "as is" without any warranty of any
		* kind, whether express or implied.
		*/

		#include <linux/platform_device.h>
		#include <linux/module.h>
		#include <linux/console.h>
		#include <linux/serial.h>
		#include <linux/serial_core.h>
		#include <linux/tty.h>
		#include <linux/delay.h>
		#include <linux/interrupt.h>
		#include <asm/io.h>

		#define ULITE_MAJOR 204
		#define ULITE_MINOR 187
		#define ULITE_NR_UARTS 4

		/* For register details see datasheet:
		http://www.xilinx.com/bvdocs/ipcenter/data_sheet/opb_uartlite.pdf
		*/
		#define ULITE_RX 0x00
		#define ULITE_TX 0x04
		#define ULITE_STATUS 0x08
		#define ULITE_CONTROL 0x0c

		#define ULITE_REGION 16

		#define ULITE_STATUS_RXVALID 0x01
		#define ULITE_STATUS_RXFULL 0x02
		#define ULITE_STATUS_TXEMPTY 0x04
		#define ULITE_STATUS_TXFULL 0x08
		#define ULITE_STATUS_IE 0x10
		#define ULITE_STATUS_OVERRUN 0x20
		#define ULITE_STATUS_FRAME 0x40
		#define ULITE_STATUS_PARITY 0x80

		#define ULITE_CONTROL_RST_TX 0x01
		#define ULITE_CONTROL_RST_RX 0x02
		#define ULITE_CONTROL_IE 0x10


		static struct uart_port ports[ULITE_NR_UARTS];

		static int ulite_receive(struct uart_port *port, int stat)
		{
		struct tty_struct *tty = port->info->tty;
		unsigned char ch = 0;
		char flag = TTY_NORMAL;

		if ((stat & (ULITE_STATUS_RXVALID \| ULITE_STATUS_OVERRUN
		\| ULITE_STATUS_FRAME)) == 0)
		return 0;

		/* stats */
		if (stat & ULITE_STATUS_RXVALID) {
		port->icount.rx++;
		ch = readb(port->membase + ULITE_RX);

		if (stat & ULITE_STATUS_PARITY)
		port->icount.parity++;
		}

		if (stat & ULITE_STATUS_OVERRUN)
		port->icount.overrun++;

		if (stat & ULITE_STATUS_FRAME)
		port->icount.frame++;


		/* drop byte with parity error if IGNPAR specificed */
		if (stat & port->ignore_status_mask & ULITE_STATUS_PARITY)
		stat &= ~ULITE_STATUS_RXVALID;

		stat &= port->read_status_mask;

		if (stat & ULITE_STATUS_PARITY)
		flag = TTY_PARITY;


		stat &= ~port->ignore_status_mask;

		if (stat & ULITE_STATUS_RXVALID)
		tty_insert_flip_char(tty, ch, flag);

		if (stat & ULITE_STATUS_FRAME)
		tty_insert_flip_char(tty, 0, TTY_FRAME);

		if (stat & ULITE_STATUS_OVERRUN)
		tty_insert_flip_char(tty, 0, TTY_OVERRUN);

		return 1;
		}

		static int ulite_transmit(struct uart_port *port, int stat)
		{
		struct circ_buf *xmit = &port->info->xmit;

		if (stat & ULITE_STATUS_TXFULL)
		return 0;

		if (port->x_char) {
		writeb(port->x_char, port->membase + ULITE_TX);
		port->x_char = 0;
		port->icount.tx++;
		return 1;
		}

		if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port))
		return 0;

		writeb(xmit->buf[xmit->tail], port->membase + ULITE_TX);
		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE-1);
		port->icount.tx++;

		/* wake up */
		if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(port);

		return 1;
		}

		static irqreturn_t ulite_isr(int irq, void *dev_id)
		{
		struct uart_port port = (struct uart_port )dev_id;
		int busy;

		do {
		int stat = readb(port->membase + ULITE_STATUS);
		busy = ulite_receive(port, stat);
		busy \|= ulite_transmit(port, stat);
		} while (busy);

		tty_flip_buffer_push(port->info->tty);

		return IRQ_HANDLED;
		}

		static unsigned int ulite_tx_empty(struct uart_port *port)
		{
		unsigned long flags;
		unsigned int ret;

		spin_lock_irqsave(&port->lock, flags);
		ret = readb(port->membase + ULITE_STATUS);
		spin_unlock_irqrestore(&port->lock, flags);

		return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
		}

		static unsigned int ulite_get_mctrl(struct uart_port *port)
		{
		return TIOCM_CTS \| TIOCM_DSR \| TIOCM_CAR;
		}

		static void ulite_set_mctrl(struct uart_port *port, unsigned int mctrl)
		{
		/* N/A */
		}

		static void ulite_stop_tx(struct uart_port *port)
		{
		/* N/A */
		}

		static void ulite_start_tx(struct uart_port *port)
		{
		ulite_transmit(port, readb(port->membase + ULITE_STATUS));
		}

		static void ulite_stop_rx(struct uart_port *port)
		{
		/* don't forward any more data (like !CREAD) */
		port->ignore_status_mask = ULITE_STATUS_RXVALID \| ULITE_STATUS_PARITY
		\| ULITE_STATUS_FRAME \| ULITE_STATUS_OVERRUN;
		}

		static void ulite_enable_ms(struct uart_port *port)
		{
		/* N/A */
		}

		static void ulite_break_ctl(struct uart_port *port, int ctl)
		{
		/* N/A */
		}

		static int ulite_startup(struct uart_port *port)
		{
		int ret;

		ret = request_irq(port->irq, ulite_isr,
		IRQF_DISABLED \| IRQF_SAMPLE_RANDOM, "uartlite", port);
		if (ret)
		return ret;

		writeb(ULITE_CONTROL_RST_RX \| ULITE_CONTROL_RST_TX,
		port->membase + ULITE_CONTROL);
		writeb(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);

		return 0;
		}

		static void ulite_shutdown(struct uart_port *port)
		{
		writeb(0, port->membase + ULITE_CONTROL);
		readb(port->membase + ULITE_CONTROL); /* dummy */
		free_irq(port->irq, port);
		}

		static void ulite_set_termios(struct uart_port port, struct termios termios,
		struct termios *old)
		{
		unsigned long flags;
		unsigned int baud;

		spin_lock_irqsave(&port->lock, flags);

		port->read_status_mask = ULITE_STATUS_RXVALID \| ULITE_STATUS_OVERRUN
		\| ULITE_STATUS_TXFULL;

		if (termios->c_iflag & INPCK)
		port->read_status_mask \|=
		ULITE_STATUS_PARITY \| ULITE_STATUS_FRAME;

		port->ignore_status_mask = 0;
		if (termios->c_iflag & IGNPAR)
		port->ignore_status_mask \|= ULITE_STATUS_PARITY
		\| ULITE_STATUS_FRAME \| ULITE_STATUS_OVERRUN;

		/* ignore all characters if CREAD is not set */
		if ((termios->c_cflag & CREAD) == 0)
		port->ignore_status_mask \|=
		ULITE_STATUS_RXVALID \| ULITE_STATUS_PARITY
		\| ULITE_STATUS_FRAME \| ULITE_STATUS_OVERRUN;

		/* update timeout */
		baud = uart_get_baud_rate(port, termios, old, 0, 460800);
		uart_update_timeout(port, termios->c_cflag, baud);

		spin_unlock_irqrestore(&port->lock, flags);
		}

		static const char ulite_type(struct uart_port port)
		{
		return port->type == PORT_UARTLITE ? "uartlite" : NULL;
		}

		static void ulite_release_port(struct uart_port *port)
		{
		release_mem_region(port->mapbase, ULITE_REGION);
		iounmap(port->membase);
		port->membase = 0;
		}

		static int ulite_request_port(struct uart_port *port)
		{
		if (!request_mem_region(port->mapbase, ULITE_REGION, "uartlite")) {
		dev_err(port->dev, "Memory region busy\n");
		return -EBUSY;
		}

		port->membase = ioremap(port->mapbase, ULITE_REGION);
		if (!port->membase) {
		dev_err(port->dev, "Unable to map registers\n");
		release_mem_region(port->mapbase, ULITE_REGION);
		return -EBUSY;
		}

		return 0;
		}

		static void ulite_config_port(struct uart_port *port, int flags)
		{
		ulite_request_port(port);
		port->type = PORT_UARTLITE;
		}

		static int ulite_verify_port(struct uart_port port, struct serial_struct ser)
		{
		/* we don't want the core code to modify any port params */
		return -EINVAL;
		}

		static struct uart_ops ulite_ops = {
		.tx_empty = ulite_tx_empty,
		.set_mctrl = ulite_set_mctrl,
		.get_mctrl = ulite_get_mctrl,
		.stop_tx = ulite_stop_tx,
		.start_tx = ulite_start_tx,
		.stop_rx = ulite_stop_rx,
		.enable_ms = ulite_enable_ms,
		.break_ctl = ulite_break_ctl,
		.startup = ulite_startup,
		.shutdown = ulite_shutdown,
		.set_termios = ulite_set_termios,
		.type = ulite_type,
		.release_port = ulite_release_port,
		.request_port = ulite_request_port,
		.config_port = ulite_config_port,
		.verify_port = ulite_verify_port
		};

		#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
		static void ulite_console_wait_tx(struct uart_port *port)
		{
		int i;

		/* wait up to 10ms for the character(s) to be sent */
		for (i = 0; i < 10000; i++) {
		if (readb(port->membase + ULITE_STATUS) & ULITE_STATUS_TXEMPTY)
		break;
		udelay(1);
		}
		}

		static void ulite_console_putchar(struct uart_port *port, int ch)
		{
		ulite_console_wait_tx(port);
		writeb(ch, port->membase + ULITE_TX);
		}

		static void ulite_console_write(struct console co, const char s,
		unsigned int count)
		{
		struct uart_port *port = &ports[co->index];
		unsigned long flags;
		unsigned int ier;
		int locked = 1;

		if (oops_in_progress) {
		locked = spin_trylock_irqsave(&port->lock, flags);
		} else
		spin_lock_irqsave(&port->lock, flags);

		/* save and disable interrupt */
		ier = readb(port->membase + ULITE_STATUS) & ULITE_STATUS_IE;
		writeb(0, port->membase + ULITE_CONTROL);

		uart_console_write(port, s, count, ulite_console_putchar);

		ulite_console_wait_tx(port);

		/* restore interrupt state */
		if (ier)
		writeb(ULITE_CONTROL_IE, port->membase + ULITE_CONTROL);

		if (locked)
		spin_unlock_irqrestore(&port->lock, flags);
		}

		static int __init ulite_console_setup(struct console co, char options)
		{
		struct uart_port *port;
		int baud = 9600;
		int bits = 8;
		int parity = 'n';
		int flow = 'n';

		if (co->index < 0 \|\| co->index >= ULITE_NR_UARTS)
		return -EINVAL;

		port = &ports[co->index];

		/* not initialized yet? */
		if (!port->membase)
		return -ENODEV;

		if (options)
		uart_parse_options(options, &baud, &parity, &bits, &flow);

		return uart_set_options(port, co, baud, parity, bits, flow);
		}

		static struct uart_driver ulite_uart_driver;

		static struct console ulite_console = {
		.name = "ttyUL",
		.write = ulite_console_write,
		.device = uart_console_device,
		.setup = ulite_console_setup,
		.flags = CON_PRINTBUFFER,
		.index = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */
		.data = &ulite_uart_driver,
		};

		static int __init ulite_console_init(void)
		{
		register_console(&ulite_console);
		return 0;
		}

		console_initcall(ulite_console_init);

		#endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */

		static struct uart_driver ulite_uart_driver = {
		.owner = THIS_MODULE,
		.driver_name = "uartlite",
		.dev_name = "ttyUL",
		.major = ULITE_MAJOR,
		.minor = ULITE_MINOR,
		.nr = ULITE_NR_UARTS,
		#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE
		.cons = &ulite_console,
		#endif
		};

		static int __devinit ulite_probe(struct platform_device *pdev)
		{
		struct resource res, res2;
		struct uart_port *port;

		if (pdev->id < 0 \|\| pdev->id >= ULITE_NR_UARTS)
		return -EINVAL;

		if (ports[pdev->id].membase)
		return -EBUSY;

		res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
		if (!res)
		return -ENODEV;

		res2 = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
		if (!res2)
		return -ENODEV;

		port = &ports[pdev->id];

		port->fifosize = 16;
		port->regshift = 2;
		port->iotype = UPIO_MEM;
		port->iobase = 1; /* mark port in use */
		port->mapbase = res->start;
		port->membase = 0;
		port->ops = &ulite_ops;
		port->irq = res2->start;
		port->flags = UPF_BOOT_AUTOCONF;
		port->dev = &pdev->dev;
		port->type = PORT_UNKNOWN;
		port->line = pdev->id;

		uart_add_one_port(&ulite_uart_driver, port);
		platform_set_drvdata(pdev, port);

		return 0;
		}

		static int ulite_remove(struct platform_device *pdev)
		{
		struct uart_port *port = platform_get_drvdata(pdev);

		platform_set_drvdata(pdev, NULL);

		if (port)
		uart_remove_one_port(&ulite_uart_driver, port);

		/* mark port as free */
		port->membase = 0;

		return 0;
		}

		static struct platform_driver ulite_platform_driver = {
		.probe = ulite_probe,
		.remove = ulite_remove,
		.driver = {
		.owner = THIS_MODULE,
		.name = "uartlite",
		},
		};

		int __init ulite_init(void)
		{
		int ret;

		ret = uart_register_driver(&ulite_uart_driver);
		if (ret)
		return ret;

		ret = platform_driver_register(&ulite_platform_driver);
		if (ret)
		uart_unregister_driver(&ulite_uart_driver);

		return ret;
		}

		void __exit ulite_exit(void)
		{
		platform_driver_unregister(&ulite_platform_driver);
		uart_unregister_driver(&ulite_uart_driver);
		}

		module_init(ulite_init);
		module_exit(ulite_exit);

		MODULE_AUTHOR("Peter Korsgaard <jacmet@sunsite.dk>");
		MODULE_DESCRIPTION("Xilinx uartlite serial driver");
		MODULE_LICENSE("GPL");

include/linux/serial_core.h

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		@@ -132,6 +132,8 @@

		#define PORT_S3C2412 73

		/* Xilinx uartlite */
		#define PORT_UARTLITE 74

		#ifdef __KERNEL__