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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/tty/serial/timbuart.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/tty/serial/timbuart.c')
-rw-r--r--drivers/tty/serial/timbuart.c496
1 files changed, 496 insertions, 0 deletions
diff --git a/drivers/tty/serial/timbuart.c b/drivers/tty/serial/timbuart.c
new file mode 100644
index 000000000..7a0326e71
--- /dev/null
+++ b/drivers/tty/serial/timbuart.c
@@ -0,0 +1,496 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * timbuart.c timberdale FPGA UART driver
+ * Copyright (c) 2009 Intel Corporation
+ */
+
+/* Supports:
+ * Timberdale FPGA UART
+ */
+
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include <linux/serial_core.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "timbuart.h"
+
+struct timbuart_port {
+ struct uart_port port;
+ struct tasklet_struct tasklet;
+ int usedma;
+ u32 last_ier;
+ struct platform_device *dev;
+};
+
+static int baudrates[] = {9600, 19200, 38400, 57600, 115200, 230400, 460800,
+ 921600, 1843200, 3250000};
+
+static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier);
+
+static irqreturn_t timbuart_handleinterrupt(int irq, void *devid);
+
+static void timbuart_stop_rx(struct uart_port *port)
+{
+ /* spin lock held by upper layer, disable all RX interrupts */
+ u32 ier = ioread32(port->membase + TIMBUART_IER) & ~RXFLAGS;
+ iowrite32(ier, port->membase + TIMBUART_IER);
+}
+
+static void timbuart_stop_tx(struct uart_port *port)
+{
+ /* spinlock held by upper layer, disable TX interrupt */
+ u32 ier = ioread32(port->membase + TIMBUART_IER) & ~TXBAE;
+ iowrite32(ier, port->membase + TIMBUART_IER);
+}
+
+static void timbuart_start_tx(struct uart_port *port)
+{
+ struct timbuart_port *uart =
+ container_of(port, struct timbuart_port, port);
+
+ /* do not transfer anything here -> fire off the tasklet */
+ tasklet_schedule(&uart->tasklet);
+}
+
+static unsigned int timbuart_tx_empty(struct uart_port *port)
+{
+ u32 isr = ioread32(port->membase + TIMBUART_ISR);
+
+ return (isr & TXBE) ? TIOCSER_TEMT : 0;
+}
+
+static void timbuart_flush_buffer(struct uart_port *port)
+{
+ if (!timbuart_tx_empty(port)) {
+ u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
+ TIMBUART_CTRL_FLSHTX;
+
+ iowrite8(ctl, port->membase + TIMBUART_CTRL);
+ iowrite32(TXBF, port->membase + TIMBUART_ISR);
+ }
+}
+
+static void timbuart_rx_chars(struct uart_port *port)
+{
+ struct tty_port *tport = &port->state->port;
+
+ while (ioread32(port->membase + TIMBUART_ISR) & RXDP) {
+ u8 ch = ioread8(port->membase + TIMBUART_RXFIFO);
+ port->icount.rx++;
+ tty_insert_flip_char(tport, ch, TTY_NORMAL);
+ }
+
+ tty_flip_buffer_push(tport);
+
+ dev_dbg(port->dev, "%s - total read %d bytes\n",
+ __func__, port->icount.rx);
+}
+
+static void timbuart_tx_chars(struct uart_port *port)
+{
+ unsigned char ch;
+
+ while (!(ioread32(port->membase + TIMBUART_ISR) & TXBF) &&
+ uart_fifo_get(port, &ch))
+ iowrite8(ch, port->membase + TIMBUART_TXFIFO);
+
+ dev_dbg(port->dev,
+ "%s - total written %d bytes, CTL: %x, RTS: %x, baud: %x\n",
+ __func__,
+ port->icount.tx,
+ ioread8(port->membase + TIMBUART_CTRL),
+ port->mctrl & TIOCM_RTS,
+ ioread8(port->membase + TIMBUART_BAUDRATE));
+}
+
+static void timbuart_handle_tx_port(struct uart_port *port, u32 isr, u32 *ier)
+{
+ struct timbuart_port *uart =
+ container_of(port, struct timbuart_port, port);
+ struct tty_port *tport = &port->state->port;
+
+ if (kfifo_is_empty(&tport->xmit_fifo) || uart_tx_stopped(port))
+ return;
+
+ if (port->x_char)
+ return;
+
+ if (isr & TXFLAGS) {
+ timbuart_tx_chars(port);
+ /* clear all TX interrupts */
+ iowrite32(TXFLAGS, port->membase + TIMBUART_ISR);
+
+ if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+ } else
+ /* Re-enable any tx interrupt */
+ *ier |= uart->last_ier & TXFLAGS;
+
+ /* enable interrupts if there are chars in the transmit buffer,
+ * Or if we delivered some bytes and want the almost empty interrupt
+ * we wake up the upper layer later when we got the interrupt
+ * to give it some time to go out...
+ */
+ if (!kfifo_is_empty(&tport->xmit_fifo))
+ *ier |= TXBAE;
+
+ dev_dbg(port->dev, "%s - leaving\n", __func__);
+}
+
+static void timbuart_handle_rx_port(struct uart_port *port, u32 isr, u32 *ier)
+{
+ if (isr & RXFLAGS) {
+ /* Some RX status is set */
+ if (isr & RXBF) {
+ u8 ctl = ioread8(port->membase + TIMBUART_CTRL) |
+ TIMBUART_CTRL_FLSHRX;
+ iowrite8(ctl, port->membase + TIMBUART_CTRL);
+ port->icount.overrun++;
+ } else if (isr & (RXDP))
+ timbuart_rx_chars(port);
+
+ /* ack all RX interrupts */
+ iowrite32(RXFLAGS, port->membase + TIMBUART_ISR);
+ }
+
+ /* always have the RX interrupts enabled */
+ *ier |= RXBAF | RXBF | RXTT;
+
+ dev_dbg(port->dev, "%s - leaving\n", __func__);
+}
+
+static void timbuart_tasklet(struct tasklet_struct *t)
+{
+ struct timbuart_port *uart = from_tasklet(uart, t, tasklet);
+ u32 isr, ier = 0;
+
+ uart_port_lock(&uart->port);
+
+ isr = ioread32(uart->port.membase + TIMBUART_ISR);
+ dev_dbg(uart->port.dev, "%s ISR: %x\n", __func__, isr);
+
+ if (!uart->usedma)
+ timbuart_handle_tx_port(&uart->port, isr, &ier);
+
+ timbuart_mctrl_check(&uart->port, isr, &ier);
+
+ if (!uart->usedma)
+ timbuart_handle_rx_port(&uart->port, isr, &ier);
+
+ iowrite32(ier, uart->port.membase + TIMBUART_IER);
+
+ uart_port_unlock(&uart->port);
+ dev_dbg(uart->port.dev, "%s leaving\n", __func__);
+}
+
+static unsigned int timbuart_get_mctrl(struct uart_port *port)
+{
+ u8 cts = ioread8(port->membase + TIMBUART_CTRL);
+ dev_dbg(port->dev, "%s - cts %x\n", __func__, cts);
+
+ if (cts & TIMBUART_CTRL_CTS)
+ return TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+ else
+ return TIOCM_DSR | TIOCM_CAR;
+}
+
+static void timbuart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ dev_dbg(port->dev, "%s - %x\n", __func__, mctrl);
+
+ if (mctrl & TIOCM_RTS)
+ iowrite8(TIMBUART_CTRL_RTS, port->membase + TIMBUART_CTRL);
+ else
+ iowrite8(0, port->membase + TIMBUART_CTRL);
+}
+
+static void timbuart_mctrl_check(struct uart_port *port, u32 isr, u32 *ier)
+{
+ unsigned int cts;
+
+ if (isr & CTS_DELTA) {
+ /* ack */
+ iowrite32(CTS_DELTA, port->membase + TIMBUART_ISR);
+ cts = timbuart_get_mctrl(port);
+ uart_handle_cts_change(port, cts & TIOCM_CTS);
+ wake_up_interruptible(&port->state->port.delta_msr_wait);
+ }
+
+ *ier |= CTS_DELTA;
+}
+
+static void timbuart_break_ctl(struct uart_port *port, int ctl)
+{
+ /* N/A */
+}
+
+static int timbuart_startup(struct uart_port *port)
+{
+ struct timbuart_port *uart =
+ container_of(port, struct timbuart_port, port);
+
+ dev_dbg(port->dev, "%s\n", __func__);
+
+ iowrite8(TIMBUART_CTRL_FLSHRX, port->membase + TIMBUART_CTRL);
+ iowrite32(0x1ff, port->membase + TIMBUART_ISR);
+ /* Enable all but TX interrupts */
+ iowrite32(RXBAF | RXBF | RXTT | CTS_DELTA,
+ port->membase + TIMBUART_IER);
+
+ return request_irq(port->irq, timbuart_handleinterrupt, IRQF_SHARED,
+ "timb-uart", uart);
+}
+
+static void timbuart_shutdown(struct uart_port *port)
+{
+ struct timbuart_port *uart =
+ container_of(port, struct timbuart_port, port);
+ dev_dbg(port->dev, "%s\n", __func__);
+ free_irq(port->irq, uart);
+ iowrite32(0, port->membase + TIMBUART_IER);
+
+ timbuart_flush_buffer(port);
+}
+
+static int get_bindex(int baud)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(baudrates); i++)
+ if (baud <= baudrates[i])
+ return i;
+
+ return -1;
+}
+
+static void timbuart_set_termios(struct uart_port *port,
+ struct ktermios *termios,
+ const struct ktermios *old)
+{
+ unsigned int baud;
+ short bindex;
+ unsigned long flags;
+
+ baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
+ bindex = get_bindex(baud);
+ dev_dbg(port->dev, "%s - bindex %d\n", __func__, bindex);
+
+ if (bindex < 0)
+ bindex = 0;
+ baud = baudrates[bindex];
+
+ /* The serial layer calls into this once with old = NULL when setting
+ up initially */
+ if (old)
+ tty_termios_copy_hw(termios, old);
+ tty_termios_encode_baud_rate(termios, baud, baud);
+
+ uart_port_lock_irqsave(port, &flags);
+ iowrite8((u8)bindex, port->membase + TIMBUART_BAUDRATE);
+ uart_update_timeout(port, termios->c_cflag, baud);
+ uart_port_unlock_irqrestore(port, flags);
+}
+
+static const char *timbuart_type(struct uart_port *port)
+{
+ return port->type == PORT_UNKNOWN ? "timbuart" : NULL;
+}
+
+/* We do not request/release mappings of the registers here,
+ * currently it's done in the proble function.
+ */
+static void timbuart_release_port(struct uart_port *port)
+{
+ struct platform_device *pdev = to_platform_device(port->dev);
+ int size =
+ resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
+
+ if (port->flags & UPF_IOREMAP) {
+ iounmap(port->membase);
+ port->membase = NULL;
+ }
+
+ release_mem_region(port->mapbase, size);
+}
+
+static int timbuart_request_port(struct uart_port *port)
+{
+ struct platform_device *pdev = to_platform_device(port->dev);
+ int size =
+ resource_size(platform_get_resource(pdev, IORESOURCE_MEM, 0));
+
+ if (!request_mem_region(port->mapbase, size, "timb-uart"))
+ return -EBUSY;
+
+ if (port->flags & UPF_IOREMAP) {
+ port->membase = ioremap(port->mapbase, size);
+ if (port->membase == NULL) {
+ release_mem_region(port->mapbase, size);
+ return -ENOMEM;
+ }
+ }
+
+ return 0;
+}
+
+static irqreturn_t timbuart_handleinterrupt(int irq, void *devid)
+{
+ struct timbuart_port *uart = (struct timbuart_port *)devid;
+
+ if (ioread8(uart->port.membase + TIMBUART_IPR)) {
+ uart->last_ier = ioread32(uart->port.membase + TIMBUART_IER);
+
+ /* disable interrupts, the tasklet enables them again */
+ iowrite32(0, uart->port.membase + TIMBUART_IER);
+
+ /* fire off bottom half */
+ tasklet_schedule(&uart->tasklet);
+
+ return IRQ_HANDLED;
+ } else
+ return IRQ_NONE;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void timbuart_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE) {
+ port->type = PORT_TIMBUART;
+ timbuart_request_port(port);
+ }
+}
+
+static int timbuart_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 const struct uart_ops timbuart_ops = {
+ .tx_empty = timbuart_tx_empty,
+ .set_mctrl = timbuart_set_mctrl,
+ .get_mctrl = timbuart_get_mctrl,
+ .stop_tx = timbuart_stop_tx,
+ .start_tx = timbuart_start_tx,
+ .flush_buffer = timbuart_flush_buffer,
+ .stop_rx = timbuart_stop_rx,
+ .break_ctl = timbuart_break_ctl,
+ .startup = timbuart_startup,
+ .shutdown = timbuart_shutdown,
+ .set_termios = timbuart_set_termios,
+ .type = timbuart_type,
+ .release_port = timbuart_release_port,
+ .request_port = timbuart_request_port,
+ .config_port = timbuart_config_port,
+ .verify_port = timbuart_verify_port
+};
+
+static struct uart_driver timbuart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "timberdale_uart",
+ .dev_name = "ttyTU",
+ .major = TIMBUART_MAJOR,
+ .minor = TIMBUART_MINOR,
+ .nr = 1
+};
+
+static int timbuart_probe(struct platform_device *dev)
+{
+ int err, irq;
+ struct timbuart_port *uart;
+ struct resource *iomem;
+
+ dev_dbg(&dev->dev, "%s\n", __func__);
+
+ uart = kzalloc_obj(*uart);
+ if (!uart) {
+ err = -EINVAL;
+ goto err_mem;
+ }
+
+ uart->usedma = 0;
+
+ uart->port.uartclk = 3250000 * 16;
+ uart->port.fifosize = TIMBUART_FIFO_SIZE;
+ uart->port.regshift = 2;
+ uart->port.iotype = UPIO_MEM;
+ uart->port.ops = &timbuart_ops;
+ uart->port.irq = 0;
+ uart->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
+ uart->port.line = 0;
+ uart->port.dev = &dev->dev;
+
+ iomem = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!iomem) {
+ err = -ENOMEM;
+ goto err_register;
+ }
+ uart->port.mapbase = iomem->start;
+ uart->port.membase = NULL;
+
+ irq = platform_get_irq(dev, 0);
+ if (irq < 0) {
+ err = -EINVAL;
+ goto err_register;
+ }
+ uart->port.irq = irq;
+
+ tasklet_setup(&uart->tasklet, timbuart_tasklet);
+
+ err = uart_register_driver(&timbuart_driver);
+ if (err)
+ goto err_register;
+
+ err = uart_add_one_port(&timbuart_driver, &uart->port);
+ if (err)
+ goto err_add_port;
+
+ platform_set_drvdata(dev, uart);
+
+ return 0;
+
+err_add_port:
+ uart_unregister_driver(&timbuart_driver);
+err_register:
+ kfree(uart);
+err_mem:
+ printk(KERN_ERR "timberdale: Failed to register Timberdale UART: %d\n",
+ err);
+
+ return err;
+}
+
+static void timbuart_remove(struct platform_device *dev)
+{
+ struct timbuart_port *uart = platform_get_drvdata(dev);
+
+ tasklet_kill(&uart->tasklet);
+ uart_remove_one_port(&timbuart_driver, &uart->port);
+ uart_unregister_driver(&timbuart_driver);
+ kfree(uart);
+}
+
+static struct platform_driver timbuart_platform_driver = {
+ .driver = {
+ .name = "timb-uart",
+ },
+ .probe = timbuart_probe,
+ .remove = timbuart_remove,
+};
+
+module_platform_driver(timbuart_platform_driver);
+
+MODULE_DESCRIPTION("Timberdale UART driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:timb-uart");
+