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authorLinus Torvalds <torvalds@linux-foundation.org>2011-10-26 15:11:09 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2011-10-26 15:11:09 +0200
commitefb8d21b2c6db3497655cc6a033ae8a9883e4063 (patch)
treea14a0dbb9fec3a6db5e542ba7ed4a49681706420 /drivers/tty/serial/8250_dw.c
parent3cb603284b3d256ae9ae9e65887cee8416bfef15 (diff)
parentd208a3bf77f902283894f546b6b5383202cf7882 (diff)
Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (79 commits) TTY: serial_core: Fix crash if DCD drop during suspend tty/serial: atmel_serial: bootconsole removed from auto-enumerates Revert "TTY: call tty_driver_lookup_tty unconditionally" tty/serial: atmel_serial: add device tree support tty/serial: atmel_serial: auto-enumerate ports tty/serial: atmel_serial: whitespace and braces modifications tty/serial: atmel_serial: change platform_data variable name tty/serial: RS485 bindings for device tree TTY: call tty_driver_lookup_tty unconditionally TTY: pty, release tty in all ptmx_open fail paths TTY: make tty_add_file non-failing TTY: drop driver reference in tty_open fail path 8250_pci: Fix kernel panic when pch_uart is disabled h8300: drivers/serial/Kconfig was moved parport_pc: release IO region properly if unsupported ITE887x card is found tty: Support compat_ioctl get/set termios_locked hvc_console: display printk messages on console. TTY: snyclinkmp: forever loop in tx_load_dma_buffer() tty/n_gsm: avoid fifo overflow in gsm_dlci_data_output tty/n_gsm: fix a bug in gsm_dlci_data_output (adaption = 2 case) ... Fix up Conflicts in: - drivers/tty/serial/8250_pci.c Trivial conflict with removed duplicate device ID - drivers/tty/serial/atmel_serial.c Annoying silly conflict between "specify the port num via platform_data" and other changes to atmel_console_init
Diffstat (limited to 'drivers/tty/serial/8250_dw.c')
-rw-r--r--drivers/tty/serial/8250_dw.c194
1 files changed, 194 insertions, 0 deletions
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 <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/serial_8250.h>
+#include <linux/serial_core.h>
+#include <linux/serial_reg.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+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");