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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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#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/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, size_t count, bool 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, size_t count, bool 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, size_t count){ struct goldfish_tty *qtty = &goldfish_ttys[line];
goldfish_tty_rw(qtty, (unsigned long)buf, count, true);}
static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id){ struct goldfish_tty *qtty = dev_id; void __iomem *base = qtty->base; u8 *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);
goldfish_tty_rw(qtty, (unsigned long)buf, count, false);
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 = kzalloc_objs(*goldfish_ttys, goldfish_tty_line_count); 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 void 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);}
#ifdef CONFIG_GOLDFISH_TTY_EARLY_CONSOLEstatic 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_DESCRIPTION("Goldfish TTY Driver");MODULE_LICENSE("GPL v2");