From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/tty/goldfish.c | 481 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 481 insertions(+) create mode 100644 drivers/tty/goldfish.c (limited to 'drivers/tty/goldfish.c') 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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"); -- cgit v1.2.3