Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 539 insertions, 0 deletions

diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c
new file mode 100644
index 000000000..c7d34823f
--- /dev/null
+++ b/drivers/tty/serial/21285.c
@@ -0,0 +1,539 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the serial port on the 21285 StrongArm-110 core logic chip.
+ *
+ * Based on drivers/char/serial.c
+ */
+#include <linux/module.h>
+#include <linux/tty.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/device.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/io.h>
+
+#include <asm/irq.h>
+#include <asm/mach-types.h>
+#include <asm/system_info.h>
+#include <asm/hardware/dec21285.h>
+#include <mach/hardware.h>
+
+#define BAUD_BASE		(mem_fclk_21285/64)
+
+#define SERIAL_21285_NAME	"ttyFB"
+#define SERIAL_21285_MAJOR	204
+#define SERIAL_21285_MINOR	4
+
+#define RXSTAT_DUMMY_READ	0x80000000
+#define RXSTAT_FRAME		(1 << 0)
+#define RXSTAT_PARITY		(1 << 1)
+#define RXSTAT_OVERRUN		(1 << 2)
+#define RXSTAT_ANYERR		(RXSTAT_FRAME|RXSTAT_PARITY|RXSTAT_OVERRUN)
+
+#define H_UBRLCR_BREAK		(1 << 0)
+#define H_UBRLCR_PARENB		(1 << 1)
+#define H_UBRLCR_PAREVN		(1 << 2)
+#define H_UBRLCR_STOPB		(1 << 3)
+#define H_UBRLCR_FIFO		(1 << 4)
+
+static const char serial21285_name[] = "Footbridge UART";
+
+/*
+ * We only need 2 bits of data, so instead of creating a whole structure for
+ * this, use bits of the private_data pointer of the uart port structure.
+ */
+#define tx_enabled_bit	0
+#define rx_enabled_bit	1
+
+static bool is_enabled(struct uart_port *port, int bit)
+{
+	unsigned long *private_data = (unsigned long *)&port->private_data;
+
+	if (test_bit(bit, private_data))
+		return true;
+	return false;
+}
+
+static void enable(struct uart_port *port, int bit)
+{
+	unsigned long *private_data = (unsigned long *)&port->private_data;
+
+	set_bit(bit, private_data);
+}
+
+static void disable(struct uart_port *port, int bit)
+{
+	unsigned long *private_data = (unsigned long *)&port->private_data;
+
+	clear_bit(bit, private_data);
+}
+
+#define is_tx_enabled(port)	is_enabled(port, tx_enabled_bit)
+#define tx_enable(port)		enable(port, tx_enabled_bit)
+#define tx_disable(port)	disable(port, tx_enabled_bit)
+
+#define is_rx_enabled(port)	is_enabled(port, rx_enabled_bit)
+#define rx_enable(port)		enable(port, rx_enabled_bit)
+#define rx_disable(port)	disable(port, rx_enabled_bit)
+
+/*
+ * The documented expression for selecting the divisor is:
+ *  BAUD_BASE / baud - 1
+ * However, typically BAUD_BASE is not divisible by baud, so
+ * we want to select the divisor that gives us the minimum
+ * error.  Therefore, we want:
+ *  int(BAUD_BASE / baud - 0.5) ->
+ *  int(BAUD_BASE / baud - (baud >> 1) / baud) ->
+ *  int((BAUD_BASE - (baud >> 1)) / baud)
+ */
+
+static void serial21285_stop_tx(struct uart_port *port)
+{
+	if (is_tx_enabled(port)) {
+		disable_irq_nosync(IRQ_CONTX);
+		tx_disable(port);
+	}
+}
+
+static void serial21285_start_tx(struct uart_port *port)
+{
+	if (!is_tx_enabled(port)) {
+		enable_irq(IRQ_CONTX);
+		tx_enable(port);
+	}
+}
+
+static void serial21285_stop_rx(struct uart_port *port)
+{
+	if (is_rx_enabled(port)) {
+		disable_irq_nosync(IRQ_CONRX);
+		rx_disable(port);
+	}
+}
+
+static irqreturn_t serial21285_rx_chars(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	unsigned int status, ch, flag, rxs, max_count = 256;
+
+	status = *CSR_UARTFLG;
+	while (!(status & 0x10) && max_count--) {
+		ch = *CSR_UARTDR;
+		flag = TTY_NORMAL;
+		port->icount.rx++;
+
+		rxs = *CSR_RXSTAT | RXSTAT_DUMMY_READ;
+		if (unlikely(rxs & RXSTAT_ANYERR)) {
+			if (rxs & RXSTAT_PARITY)
+				port->icount.parity++;
+			else if (rxs & RXSTAT_FRAME)
+				port->icount.frame++;
+			if (rxs & RXSTAT_OVERRUN)
+				port->icount.overrun++;
+
+			rxs &= port->read_status_mask;
+
+			if (rxs & RXSTAT_PARITY)
+				flag = TTY_PARITY;
+			else if (rxs & RXSTAT_FRAME)
+				flag = TTY_FRAME;
+		}
+
+		uart_insert_char(port, rxs, RXSTAT_OVERRUN, ch, flag);
+
+		status = *CSR_UARTFLG;
+	}
+	tty_flip_buffer_push(&port->state->port);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t serial21285_tx_chars(int irq, void *dev_id)
+{
+	struct uart_port *port = dev_id;
+	struct circ_buf *xmit = &port->state->xmit;
+	int count = 256;
+
+	if (port->x_char) {
+		*CSR_UARTDR = port->x_char;
+		port->icount.tx++;
+		port->x_char = 0;
+		goto out;
+	}
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		serial21285_stop_tx(port);
+		goto out;
+	}
+
+	do {
+		*CSR_UARTDR = xmit->buf[xmit->tail];
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+		if (uart_circ_empty(xmit))
+			break;
+	} while (--count > 0 && !(*CSR_UARTFLG & 0x20));
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (uart_circ_empty(xmit))
+		serial21285_stop_tx(port);
+
+ out:
+	return IRQ_HANDLED;
+}
+
+static unsigned int serial21285_tx_empty(struct uart_port *port)
+{
+	return (*CSR_UARTFLG & 8) ? 0 : TIOCSER_TEMT;
+}
+
+/* no modem control lines */
+static unsigned int serial21285_get_mctrl(struct uart_port *port)
+{
+	return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
+}
+
+static void serial21285_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static void serial21285_break_ctl(struct uart_port *port, int break_state)
+{
+	unsigned long flags;
+	unsigned int h_lcr;
+
+	spin_lock_irqsave(&port->lock, flags);
+	h_lcr = *CSR_H_UBRLCR;
+	if (break_state)
+		h_lcr |= H_UBRLCR_BREAK;
+	else
+		h_lcr &= ~H_UBRLCR_BREAK;
+	*CSR_H_UBRLCR = h_lcr;
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static int serial21285_startup(struct uart_port *port)
+{
+	int ret;
+
+	tx_enable(port);
+	rx_enable(port);
+
+	ret = request_irq(IRQ_CONRX, serial21285_rx_chars, 0,
+			  serial21285_name, port);
+	if (ret == 0) {
+		ret = request_irq(IRQ_CONTX, serial21285_tx_chars, 0,
+				  serial21285_name, port);
+		if (ret)
+			free_irq(IRQ_CONRX, port);
+	}
+
+	return ret;
+}
+
+static void serial21285_shutdown(struct uart_port *port)
+{
+	free_irq(IRQ_CONTX, port);
+	free_irq(IRQ_CONRX, port);
+}
+
+static void
+serial21285_set_termios(struct uart_port *port, struct ktermios *termios,
+			const struct ktermios *old)
+{
+	unsigned long flags;
+	unsigned int baud, quot, h_lcr, b;
+
+	/*
+	 * We don't support modem control lines.
+	 */
+	termios->c_cflag &= ~(HUPCL | CRTSCTS | CMSPAR);
+	termios->c_cflag |= CLOCAL;
+
+	/*
+	 * We don't support BREAK character recognition.
+	 */
+	termios->c_iflag &= ~(IGNBRK | BRKINT);
+
+	/*
+	 * Ask the core to calculate the divisor for us.
+	 */
+	baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16); 
+	quot = uart_get_divisor(port, baud);
+	b = port->uartclk / (16 * quot);
+	tty_termios_encode_baud_rate(termios, b, b);
+
+	switch (termios->c_cflag & CSIZE) {
+	case CS5:
+		h_lcr = 0x00;
+		break;
+	case CS6:
+		h_lcr = 0x20;
+		break;
+	case CS7:
+		h_lcr = 0x40;
+		break;
+	default: /* CS8 */
+		h_lcr = 0x60;
+		break;
+	}
+
+	if (termios->c_cflag & CSTOPB)
+		h_lcr |= H_UBRLCR_STOPB;
+	if (termios->c_cflag & PARENB) {
+		h_lcr |= H_UBRLCR_PARENB;
+		if (!(termios->c_cflag & PARODD))
+			h_lcr |= H_UBRLCR_PAREVN;
+	}
+
+	if (port->fifosize)
+		h_lcr |= H_UBRLCR_FIFO;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	/*
+	 * Update the per-port timeout.
+	 */
+	uart_update_timeout(port, termios->c_cflag, baud);
+
+	/*
+	 * Which character status flags are we interested in?
+	 */
+	port->read_status_mask = RXSTAT_OVERRUN;
+	if (termios->c_iflag & INPCK)
+		port->read_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY;
+
+	/*
+	 * Which character status flags should we ignore?
+	 */
+	port->ignore_status_mask = 0;
+	if (termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= RXSTAT_FRAME | RXSTAT_PARITY;
+	if (termios->c_iflag & IGNBRK && termios->c_iflag & IGNPAR)
+		port->ignore_status_mask |= RXSTAT_OVERRUN;
+
+	/*
+	 * Ignore all characters if CREAD is not set.
+	 */
+	if ((termios->c_cflag & CREAD) == 0)
+		port->ignore_status_mask |= RXSTAT_DUMMY_READ;
+
+	quot -= 1;
+
+	*CSR_UARTCON = 0;
+	*CSR_L_UBRLCR = quot & 0xff;
+	*CSR_M_UBRLCR = (quot >> 8) & 0x0f;
+	*CSR_H_UBRLCR = h_lcr;
+	*CSR_UARTCON = 1;
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *serial21285_type(struct uart_port *port)
+{
+	return port->type == PORT_21285 ? "DC21285" : NULL;
+}
+
+static void serial21285_release_port(struct uart_port *port)
+{
+	release_mem_region(port->mapbase, 32);
+}
+
+static int serial21285_request_port(struct uart_port *port)
+{
+	return request_mem_region(port->mapbase, 32, serial21285_name)
+			 != NULL ? 0 : -EBUSY;
+}
+
+static void serial21285_config_port(struct uart_port *port, int flags)
+{
+	if (flags & UART_CONFIG_TYPE && serial21285_request_port(port) == 0)
+		port->type = PORT_21285;
+}
+
+/*
+ * verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int serial21285_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+	int ret = 0;
+	if (ser->type != PORT_UNKNOWN && ser->type != PORT_21285)
+		ret = -EINVAL;
+	if (ser->irq <= 0)
+		ret = -EINVAL;
+	if (ser->baud_base != port->uartclk / 16)
+		ret = -EINVAL;
+	return ret;
+}
+
+static const struct uart_ops serial21285_ops = {
+	.tx_empty	= serial21285_tx_empty,
+	.get_mctrl	= serial21285_get_mctrl,
+	.set_mctrl	= serial21285_set_mctrl,
+	.stop_tx	= serial21285_stop_tx,
+	.start_tx	= serial21285_start_tx,
+	.stop_rx	= serial21285_stop_rx,
+	.break_ctl	= serial21285_break_ctl,
+	.startup	= serial21285_startup,
+	.shutdown	= serial21285_shutdown,
+	.set_termios	= serial21285_set_termios,
+	.type		= serial21285_type,
+	.release_port	= serial21285_release_port,
+	.request_port	= serial21285_request_port,
+	.config_port	= serial21285_config_port,
+	.verify_port	= serial21285_verify_port,
+};
+
+static struct uart_port serial21285_port = {
+	.mapbase	= 0x42000160,
+	.iotype		= UPIO_MEM,
+	.irq		= 0,
+	.fifosize	= 16,
+	.ops		= &serial21285_ops,
+	.flags		= UPF_BOOT_AUTOCONF,
+};
+
+static void serial21285_setup_ports(void)
+{
+	serial21285_port.uartclk = mem_fclk_21285 / 4;
+}
+
+#ifdef CONFIG_SERIAL_21285_CONSOLE
+static void serial21285_console_putchar(struct uart_port *port, unsigned char ch)
+{
+	while (*CSR_UARTFLG & 0x20)
+		barrier();
+	*CSR_UARTDR = ch;
+}
+
+static void
+serial21285_console_write(struct console *co, const char *s,
+			  unsigned int count)
+{
+	uart_console_write(&serial21285_port, s, count, serial21285_console_putchar);
+}
+
+static void __init
+serial21285_get_options(struct uart_port *port, int *baud,
+			int *parity, int *bits)
+{
+	if (*CSR_UARTCON == 1) {
+		unsigned int tmp;
+
+		tmp = *CSR_H_UBRLCR;
+		switch (tmp & 0x60) {
+		case 0x00:
+			*bits = 5;
+			break;
+		case 0x20:
+			*bits = 6;
+			break;
+		case 0x40:
+			*bits = 7;
+			break;
+		default:
+		case 0x60:
+			*bits = 8;
+			break;
+		}
+
+		if (tmp & H_UBRLCR_PARENB) {
+			*parity = 'o';
+			if (tmp & H_UBRLCR_PAREVN)
+				*parity = 'e';
+		}
+
+		tmp = *CSR_L_UBRLCR | (*CSR_M_UBRLCR << 8);
+
+		*baud = port->uartclk / (16 * (tmp + 1));
+	}
+}
+
+static int __init serial21285_console_setup(struct console *co, char *options)
+{
+	struct uart_port *port = &serial21285_port;
+	int baud = 9600;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+
+	/*
+	 * Check whether an invalid uart number has been specified, and
+	 * if so, search for the first available port that does have
+	 * console support.
+	 */
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		serial21285_get_options(port, &baud, &parity, &bits);
+
+	return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver serial21285_reg;
+
+static struct console serial21285_console =
+{
+	.name		= SERIAL_21285_NAME,
+	.write		= serial21285_console_write,
+	.device		= uart_console_device,
+	.setup		= serial21285_console_setup,
+	.flags		= CON_PRINTBUFFER,
+	.index		= -1,
+	.data		= &serial21285_reg,
+};
+
+static int __init rs285_console_init(void)
+{
+	serial21285_setup_ports();
+	register_console(&serial21285_console);
+	return 0;
+}
+console_initcall(rs285_console_init);
+
+#define SERIAL_21285_CONSOLE	&serial21285_console
+#else
+#define SERIAL_21285_CONSOLE	NULL
+#endif
+
+static struct uart_driver serial21285_reg = {
+	.owner			= THIS_MODULE,
+	.driver_name		= "ttyFB",
+	.dev_name		= "ttyFB",
+	.major			= SERIAL_21285_MAJOR,
+	.minor			= SERIAL_21285_MINOR,
+	.nr			= 1,
+	.cons			= SERIAL_21285_CONSOLE,
+};
+
+static int __init serial21285_init(void)
+{
+	int ret;
+
+	printk(KERN_INFO "Serial: 21285 driver\n");
+
+	serial21285_setup_ports();
+
+	ret = uart_register_driver(&serial21285_reg);
+	if (ret == 0)
+		uart_add_one_port(&serial21285_reg, &serial21285_port);
+
+	return ret;
+}
+
+static void __exit serial21285_exit(void)
+{
+	uart_remove_one_port(&serial21285_reg, &serial21285_port);
+	uart_unregister_driver(&serial21285_reg);
+}
+
+module_init(serial21285_init);
+module_exit(serial21285_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Intel Footbridge (21285) serial driver");
+MODULE_ALIAS_CHARDEV(SERIAL_21285_MAJOR, SERIAL_21285_MINOR);