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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/tty/goldfish.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/tty/goldfish.c')
-rw-r--r--drivers/tty/goldfish.c481
1 files changed, 481 insertions, 0 deletions
diff --git a/drivers/tty/goldfish.c b/drivers/tty/goldfish.c
new file mode 100644
index 0000000000..4591f940b7
--- /dev/null
+++ b/drivers/tty/goldfish.c
@@ -0,0 +1,481 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (C) 2012 Intel, Inc.
+ * Copyright (C) 2017 Imagination Technologies Ltd.
+ */
+
+#include <linux/console.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/goldfish.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/serial_core.h>
+
+/* Goldfish tty register's offsets */
+#define GOLDFISH_TTY_REG_BYTES_READY 0x04
+#define GOLDFISH_TTY_REG_CMD 0x08
+#define GOLDFISH_TTY_REG_DATA_PTR 0x10
+#define GOLDFISH_TTY_REG_DATA_LEN 0x14
+#define GOLDFISH_TTY_REG_DATA_PTR_HIGH 0x18
+#define GOLDFISH_TTY_REG_VERSION 0x20
+
+/* Goldfish tty commands */
+#define GOLDFISH_TTY_CMD_INT_DISABLE 0
+#define GOLDFISH_TTY_CMD_INT_ENABLE 1
+#define GOLDFISH_TTY_CMD_WRITE_BUFFER 2
+#define GOLDFISH_TTY_CMD_READ_BUFFER 3
+
+struct goldfish_tty {
+ struct tty_port port;
+ spinlock_t lock;
+ void __iomem *base;
+ u32 irq;
+ int opencount;
+ struct console console;
+ u32 version;
+ struct device *dev;
+};
+
+static DEFINE_MUTEX(goldfish_tty_lock);
+static struct tty_driver *goldfish_tty_driver;
+static u32 goldfish_tty_line_count = 8;
+static u32 goldfish_tty_current_line_count;
+static struct goldfish_tty *goldfish_ttys;
+
+static void do_rw_io(struct goldfish_tty *qtty,
+ unsigned long address,
+ unsigned int count,
+ int is_write)
+{
+ unsigned long irq_flags;
+ void __iomem *base = qtty->base;
+
+ spin_lock_irqsave(&qtty->lock, irq_flags);
+ gf_write_ptr((void *)address, base + GOLDFISH_TTY_REG_DATA_PTR,
+ base + GOLDFISH_TTY_REG_DATA_PTR_HIGH);
+ gf_iowrite32(count, base + GOLDFISH_TTY_REG_DATA_LEN);
+
+ if (is_write)
+ gf_iowrite32(GOLDFISH_TTY_CMD_WRITE_BUFFER,
+ base + GOLDFISH_TTY_REG_CMD);
+ else
+ gf_iowrite32(GOLDFISH_TTY_CMD_READ_BUFFER,
+ base + GOLDFISH_TTY_REG_CMD);
+
+ spin_unlock_irqrestore(&qtty->lock, irq_flags);
+}
+
+static void goldfish_tty_rw(struct goldfish_tty *qtty,
+ unsigned long addr,
+ unsigned int count,
+ int is_write)
+{
+ dma_addr_t dma_handle;
+ enum dma_data_direction dma_dir;
+
+ dma_dir = (is_write ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+ if (qtty->version > 0) {
+ /*
+ * Goldfish TTY for Ranchu platform uses
+ * physical addresses and DMA for read/write operations
+ */
+ unsigned long addr_end = addr + count;
+
+ while (addr < addr_end) {
+ unsigned long pg_end = (addr & PAGE_MASK) + PAGE_SIZE;
+ unsigned long next =
+ pg_end < addr_end ? pg_end : addr_end;
+ unsigned long avail = next - addr;
+
+ /*
+ * Map the buffer's virtual address to the DMA address
+ * so the buffer can be accessed by the device.
+ */
+ dma_handle = dma_map_single(qtty->dev, (void *)addr,
+ avail, dma_dir);
+
+ if (dma_mapping_error(qtty->dev, dma_handle)) {
+ dev_err(qtty->dev, "tty: DMA mapping error.\n");
+ return;
+ }
+ do_rw_io(qtty, dma_handle, avail, is_write);
+
+ /*
+ * Unmap the previously mapped region after
+ * the completion of the read/write operation.
+ */
+ dma_unmap_single(qtty->dev, dma_handle, avail, dma_dir);
+
+ addr += avail;
+ }
+ } else {
+ /*
+ * Old style Goldfish TTY used on the Goldfish platform
+ * uses virtual addresses.
+ */
+ do_rw_io(qtty, addr, count, is_write);
+ }
+}
+
+static void goldfish_tty_do_write(int line, const u8 *buf, unsigned int count)
+{
+ struct goldfish_tty *qtty = &goldfish_ttys[line];
+ unsigned long address = (unsigned long)(void *)buf;
+
+ goldfish_tty_rw(qtty, address, count, 1);
+}
+
+static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
+{
+ struct goldfish_tty *qtty = dev_id;
+ void __iomem *base = qtty->base;
+ unsigned long address;
+ unsigned char *buf;
+ u32 count;
+
+ count = gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY);
+ if (count == 0)
+ return IRQ_NONE;
+
+ count = tty_prepare_flip_string(&qtty->port, &buf, count);
+
+ address = (unsigned long)(void *)buf;
+ goldfish_tty_rw(qtty, address, count, 0);
+
+ tty_flip_buffer_push(&qtty->port);
+ return IRQ_HANDLED;
+}
+
+static int goldfish_tty_activate(struct tty_port *port, struct tty_struct *tty)
+{
+ struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
+ port);
+ gf_iowrite32(GOLDFISH_TTY_CMD_INT_ENABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
+ return 0;
+}
+
+static void goldfish_tty_shutdown(struct tty_port *port)
+{
+ struct goldfish_tty *qtty = container_of(port, struct goldfish_tty,
+ port);
+ gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, qtty->base + GOLDFISH_TTY_REG_CMD);
+}
+
+static int goldfish_tty_open(struct tty_struct *tty, struct file *filp)
+{
+ struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
+ return tty_port_open(&qtty->port, tty, filp);
+}
+
+static void goldfish_tty_close(struct tty_struct *tty, struct file *filp)
+{
+ tty_port_close(tty->port, tty, filp);
+}
+
+static void goldfish_tty_hangup(struct tty_struct *tty)
+{
+ tty_port_hangup(tty->port);
+}
+
+static ssize_t goldfish_tty_write(struct tty_struct *tty, const u8 *buf,
+ size_t count)
+{
+ goldfish_tty_do_write(tty->index, buf, count);
+ return count;
+}
+
+static unsigned int goldfish_tty_write_room(struct tty_struct *tty)
+{
+ return 0x10000;
+}
+
+static unsigned int goldfish_tty_chars_in_buffer(struct tty_struct *tty)
+{
+ struct goldfish_tty *qtty = &goldfish_ttys[tty->index];
+ void __iomem *base = qtty->base;
+ return gf_ioread32(base + GOLDFISH_TTY_REG_BYTES_READY);
+}
+
+static void goldfish_tty_console_write(struct console *co, const char *b,
+ unsigned count)
+{
+ goldfish_tty_do_write(co->index, b, count);
+}
+
+static struct tty_driver *goldfish_tty_console_device(struct console *c,
+ int *index)
+{
+ *index = c->index;
+ return goldfish_tty_driver;
+}
+
+static int goldfish_tty_console_setup(struct console *co, char *options)
+{
+ if ((unsigned)co->index >= goldfish_tty_line_count)
+ return -ENODEV;
+ if (!goldfish_ttys[co->index].base)
+ return -ENODEV;
+ return 0;
+}
+
+static const struct tty_port_operations goldfish_port_ops = {
+ .activate = goldfish_tty_activate,
+ .shutdown = goldfish_tty_shutdown
+};
+
+static const struct tty_operations goldfish_tty_ops = {
+ .open = goldfish_tty_open,
+ .close = goldfish_tty_close,
+ .hangup = goldfish_tty_hangup,
+ .write = goldfish_tty_write,
+ .write_room = goldfish_tty_write_room,
+ .chars_in_buffer = goldfish_tty_chars_in_buffer,
+};
+
+static int goldfish_tty_create_driver(void)
+{
+ int ret;
+ struct tty_driver *tty;
+
+ goldfish_ttys = kcalloc(goldfish_tty_line_count,
+ sizeof(*goldfish_ttys),
+ GFP_KERNEL);
+ if (goldfish_ttys == NULL) {
+ ret = -ENOMEM;
+ goto err_alloc_goldfish_ttys_failed;
+ }
+ tty = tty_alloc_driver(goldfish_tty_line_count,
+ TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW |
+ TTY_DRIVER_DYNAMIC_DEV);
+ if (IS_ERR(tty)) {
+ ret = PTR_ERR(tty);
+ goto err_tty_alloc_driver_failed;
+ }
+ tty->driver_name = "goldfish";
+ tty->name = "ttyGF";
+ tty->type = TTY_DRIVER_TYPE_SERIAL;
+ tty->subtype = SERIAL_TYPE_NORMAL;
+ tty->init_termios = tty_std_termios;
+ tty_set_operations(tty, &goldfish_tty_ops);
+ ret = tty_register_driver(tty);
+ if (ret)
+ goto err_tty_register_driver_failed;
+
+ goldfish_tty_driver = tty;
+ return 0;
+
+err_tty_register_driver_failed:
+ tty_driver_kref_put(tty);
+err_tty_alloc_driver_failed:
+ kfree(goldfish_ttys);
+ goldfish_ttys = NULL;
+err_alloc_goldfish_ttys_failed:
+ return ret;
+}
+
+static void goldfish_tty_delete_driver(void)
+{
+ tty_unregister_driver(goldfish_tty_driver);
+ tty_driver_kref_put(goldfish_tty_driver);
+ goldfish_tty_driver = NULL;
+ kfree(goldfish_ttys);
+ goldfish_ttys = NULL;
+}
+
+static int goldfish_tty_probe(struct platform_device *pdev)
+{
+ struct goldfish_tty *qtty;
+ int ret = -ENODEV;
+ struct resource *r;
+ struct device *ttydev;
+ void __iomem *base;
+ int irq;
+ unsigned int line;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ pr_err("goldfish_tty: No MEM resource available!\n");
+ return -ENOMEM;
+ }
+
+ base = ioremap(r->start, 0x1000);
+ if (!base) {
+ pr_err("goldfish_tty: Unable to ioremap base!\n");
+ return -ENOMEM;
+ }
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0) {
+ ret = irq;
+ goto err_unmap;
+ }
+
+ mutex_lock(&goldfish_tty_lock);
+
+ if (pdev->id == PLATFORM_DEVID_NONE)
+ line = goldfish_tty_current_line_count;
+ else
+ line = pdev->id;
+
+ if (line >= goldfish_tty_line_count) {
+ pr_err("goldfish_tty: Reached maximum tty number of %d.\n",
+ goldfish_tty_current_line_count);
+ ret = -ENOMEM;
+ goto err_unlock;
+ }
+
+ if (goldfish_tty_current_line_count == 0) {
+ ret = goldfish_tty_create_driver();
+ if (ret)
+ goto err_unlock;
+ }
+ goldfish_tty_current_line_count++;
+
+ qtty = &goldfish_ttys[line];
+ spin_lock_init(&qtty->lock);
+ tty_port_init(&qtty->port);
+ qtty->port.ops = &goldfish_port_ops;
+ qtty->base = base;
+ qtty->irq = irq;
+ qtty->dev = &pdev->dev;
+
+ /*
+ * Goldfish TTY device used by the Goldfish emulator
+ * should identify itself with 0, forcing the driver
+ * to use virtual addresses. Goldfish TTY device
+ * on Ranchu emulator (qemu2) returns 1 here and
+ * driver will use physical addresses.
+ */
+ qtty->version = gf_ioread32(base + GOLDFISH_TTY_REG_VERSION);
+
+ /*
+ * Goldfish TTY device on Ranchu emulator (qemu2)
+ * will use DMA for read/write IO operations.
+ */
+ if (qtty->version > 0) {
+ /*
+ * Initialize dma_mask to 32-bits.
+ */
+ if (!pdev->dev.dma_mask)
+ pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
+ ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
+ if (ret) {
+ dev_err(&pdev->dev, "No suitable DMA available.\n");
+ goto err_dec_line_count;
+ }
+ }
+
+ gf_iowrite32(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_REG_CMD);
+
+ ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
+ "goldfish_tty", qtty);
+ if (ret) {
+ pr_err("goldfish_tty: No IRQ available!\n");
+ goto err_dec_line_count;
+ }
+
+ ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
+ line, &pdev->dev);
+ if (IS_ERR(ttydev)) {
+ ret = PTR_ERR(ttydev);
+ goto err_tty_register_device_failed;
+ }
+
+ strcpy(qtty->console.name, "ttyGF");
+ qtty->console.write = goldfish_tty_console_write;
+ qtty->console.device = goldfish_tty_console_device;
+ qtty->console.setup = goldfish_tty_console_setup;
+ qtty->console.flags = CON_PRINTBUFFER;
+ qtty->console.index = line;
+ register_console(&qtty->console);
+ platform_set_drvdata(pdev, qtty);
+
+ mutex_unlock(&goldfish_tty_lock);
+ return 0;
+
+err_tty_register_device_failed:
+ free_irq(irq, qtty);
+err_dec_line_count:
+ tty_port_destroy(&qtty->port);
+ goldfish_tty_current_line_count--;
+ if (goldfish_tty_current_line_count == 0)
+ goldfish_tty_delete_driver();
+err_unlock:
+ mutex_unlock(&goldfish_tty_lock);
+err_unmap:
+ iounmap(base);
+ return ret;
+}
+
+static int goldfish_tty_remove(struct platform_device *pdev)
+{
+ struct goldfish_tty *qtty = platform_get_drvdata(pdev);
+
+ mutex_lock(&goldfish_tty_lock);
+
+ unregister_console(&qtty->console);
+ tty_unregister_device(goldfish_tty_driver, qtty->console.index);
+ iounmap(qtty->base);
+ qtty->base = NULL;
+ free_irq(qtty->irq, qtty);
+ tty_port_destroy(&qtty->port);
+ goldfish_tty_current_line_count--;
+ if (goldfish_tty_current_line_count == 0)
+ goldfish_tty_delete_driver();
+ mutex_unlock(&goldfish_tty_lock);
+ return 0;
+}
+
+#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLE
+static void gf_early_console_putchar(struct uart_port *port, unsigned char ch)
+{
+ gf_iowrite32(ch, port->membase);
+}
+
+static void gf_early_write(struct console *con, const char *s, unsigned int n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, gf_early_console_putchar);
+}
+
+static int __init gf_earlycon_setup(struct earlycon_device *device,
+ const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = gf_early_write;
+ return 0;
+}
+
+OF_EARLYCON_DECLARE(early_gf_tty, "google,goldfish-tty", gf_earlycon_setup);
+#endif
+
+static const struct of_device_id goldfish_tty_of_match[] = {
+ { .compatible = "google,goldfish-tty", },
+ {},
+};
+
+MODULE_DEVICE_TABLE(of, goldfish_tty_of_match);
+
+static struct platform_driver goldfish_tty_platform_driver = {
+ .probe = goldfish_tty_probe,
+ .remove = goldfish_tty_remove,
+ .driver = {
+ .name = "goldfish_tty",
+ .of_match_table = goldfish_tty_of_match,
+ }
+};
+
+module_platform_driver(goldfish_tty_platform_driver);
+
+MODULE_LICENSE("GPL v2");