diff options
Diffstat (limited to 'ANDROID_3.4.5/drivers/tty/ehv_bytechan.c')
| -rw-r--r-- | ANDROID_3.4.5/drivers/tty/ehv_bytechan.c | 880 |
1 files changed, 0 insertions, 880 deletions
diff --git a/ANDROID_3.4.5/drivers/tty/ehv_bytechan.c b/ANDROID_3.4.5/drivers/tty/ehv_bytechan.c deleted file mode 100644 index 4813684c..00000000 --- a/ANDROID_3.4.5/drivers/tty/ehv_bytechan.c +++ /dev/null @@ -1,880 +0,0 @@ -/* ePAPR hypervisor byte channel device driver - * - * Copyright 2009-2011 Freescale Semiconductor, Inc. - * - * Author: Timur Tabi <timur@freescale.com> - * - * This file is licensed under the terms of the GNU General Public License - * version 2. This program is licensed "as is" without any warranty of any - * kind, whether express or implied. - * - * This driver support three distinct interfaces, all of which are related to - * ePAPR hypervisor byte channels. - * - * 1) An early-console (udbg) driver. This provides early console output - * through a byte channel. The byte channel handle must be specified in a - * Kconfig option. - * - * 2) A normal console driver. Output is sent to the byte channel designated - * for stdout in the device tree. The console driver is for handling kernel - * printk calls. - * - * 3) A tty driver, which is used to handle user-space input and output. The - * byte channel used for the console is designated as the default tty. - */ - -#include <linux/module.h> -#include <linux/init.h> -#include <linux/slab.h> -#include <linux/err.h> -#include <linux/interrupt.h> -#include <linux/fs.h> -#include <linux/poll.h> -#include <asm/epapr_hcalls.h> -#include <linux/of.h> -#include <linux/platform_device.h> -#include <linux/cdev.h> -#include <linux/console.h> -#include <linux/tty.h> -#include <linux/tty_flip.h> -#include <linux/circ_buf.h> -#include <asm/udbg.h> - -/* The size of the transmit circular buffer. This must be a power of two. */ -#define BUF_SIZE 2048 - -/* Per-byte channel private data */ -struct ehv_bc_data { - struct device *dev; - struct tty_port port; - uint32_t handle; - unsigned int rx_irq; - unsigned int tx_irq; - - spinlock_t lock; /* lock for transmit buffer */ - unsigned char buf[BUF_SIZE]; /* transmit circular buffer */ - unsigned int head; /* circular buffer head */ - unsigned int tail; /* circular buffer tail */ - - int tx_irq_enabled; /* true == TX interrupt is enabled */ -}; - -/* Array of byte channel objects */ -static struct ehv_bc_data *bcs; - -/* Byte channel handle for stdout (and stdin), taken from device tree */ -static unsigned int stdout_bc; - -/* Virtual IRQ for the byte channel handle for stdin, taken from device tree */ -static unsigned int stdout_irq; - -/**************************** SUPPORT FUNCTIONS ****************************/ - -/* - * Enable the transmit interrupt - * - * Unlike a serial device, byte channels have no mechanism for disabling their - * own receive or transmit interrupts. To emulate that feature, we toggle - * the IRQ in the kernel. - * - * We cannot just blindly call enable_irq() or disable_irq(), because these - * calls are reference counted. This means that we cannot call enable_irq() - * if interrupts are already enabled. This can happen in two situations: - * - * 1. The tty layer makes two back-to-back calls to ehv_bc_tty_write() - * 2. A transmit interrupt occurs while executing ehv_bc_tx_dequeue() - * - * To work around this, we keep a flag to tell us if the IRQ is enabled or not. - */ -static void enable_tx_interrupt(struct ehv_bc_data *bc) -{ - if (!bc->tx_irq_enabled) { - enable_irq(bc->tx_irq); - bc->tx_irq_enabled = 1; - } -} - -static void disable_tx_interrupt(struct ehv_bc_data *bc) -{ - if (bc->tx_irq_enabled) { - disable_irq_nosync(bc->tx_irq); - bc->tx_irq_enabled = 0; - } -} - -/* - * find the byte channel handle to use for the console - * - * The byte channel to be used for the console is specified via a "stdout" - * property in the /chosen node. - * - * For compatible with legacy device trees, we also look for a "stdout" alias. - */ -static int find_console_handle(void) -{ - struct device_node *np, *np2; - const char *sprop = NULL; - const uint32_t *iprop; - - np = of_find_node_by_path("/chosen"); - if (np) - sprop = of_get_property(np, "stdout-path", NULL); - - if (!np || !sprop) { - of_node_put(np); - np = of_find_node_by_name(NULL, "aliases"); - if (np) - sprop = of_get_property(np, "stdout", NULL); - } - - if (!sprop) { - of_node_put(np); - return 0; - } - - /* We don't care what the aliased node is actually called. We only - * care if it's compatible with "epapr,hv-byte-channel", because that - * indicates that it's a byte channel node. We use a temporary - * variable, 'np2', because we can't release 'np' until we're done with - * 'sprop'. - */ - np2 = of_find_node_by_path(sprop); - of_node_put(np); - np = np2; - if (!np) { - pr_warning("ehv-bc: stdout node '%s' does not exist\n", sprop); - return 0; - } - - /* Is it a byte channel? */ - if (!of_device_is_compatible(np, "epapr,hv-byte-channel")) { - of_node_put(np); - return 0; - } - - stdout_irq = irq_of_parse_and_map(np, 0); - if (stdout_irq == NO_IRQ) { - pr_err("ehv-bc: no 'interrupts' property in %s node\n", sprop); - of_node_put(np); - return 0; - } - - /* - * The 'hv-handle' property contains the handle for this byte channel. - */ - iprop = of_get_property(np, "hv-handle", NULL); - if (!iprop) { - pr_err("ehv-bc: no 'hv-handle' property in %s node\n", - np->name); - of_node_put(np); - return 0; - } - stdout_bc = be32_to_cpu(*iprop); - - of_node_put(np); - return 1; -} - -/*************************** EARLY CONSOLE DRIVER ***************************/ - -#ifdef CONFIG_PPC_EARLY_DEBUG_EHV_BC - -/* - * send a byte to a byte channel, wait if necessary - * - * This function sends a byte to a byte channel, and it waits and - * retries if the byte channel is full. It returns if the character - * has been sent, or if some error has occurred. - * - */ -static void byte_channel_spin_send(const char data) -{ - int ret, count; - - do { - count = 1; - ret = ev_byte_channel_send(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE, - &count, &data); - } while (ret == EV_EAGAIN); -} - -/* - * The udbg subsystem calls this function to display a single character. - * We convert CR to a CR/LF. - */ -static void ehv_bc_udbg_putc(char c) -{ - if (c == '\n') - byte_channel_spin_send('\r'); - - byte_channel_spin_send(c); -} - -/* - * early console initialization - * - * PowerPC kernels support an early printk console, also known as udbg. - * This function must be called via the ppc_md.init_early function pointer. - * At this point, the device tree has been unflattened, so we can obtain the - * byte channel handle for stdout. - * - * We only support displaying of characters (putc). We do not support - * keyboard input. - */ -void __init udbg_init_ehv_bc(void) -{ - unsigned int rx_count, tx_count; - unsigned int ret; - - /* Verify the byte channel handle */ - ret = ev_byte_channel_poll(CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE, - &rx_count, &tx_count); - if (ret) - return; - - udbg_putc = ehv_bc_udbg_putc; - register_early_udbg_console(); - - udbg_printf("ehv-bc: early console using byte channel handle %u\n", - CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE); -} - -#endif - -/****************************** CONSOLE DRIVER ******************************/ - -static struct tty_driver *ehv_bc_driver; - -/* - * Byte channel console sending worker function. - * - * For consoles, if the output buffer is full, we should just spin until it - * clears. - */ -static int ehv_bc_console_byte_channel_send(unsigned int handle, const char *s, - unsigned int count) -{ - unsigned int len; - int ret = 0; - - while (count) { - len = min_t(unsigned int, count, EV_BYTE_CHANNEL_MAX_BYTES); - do { - ret = ev_byte_channel_send(handle, &len, s); - } while (ret == EV_EAGAIN); - count -= len; - s += len; - } - - return ret; -} - -/* - * write a string to the console - * - * This function gets called to write a string from the kernel, typically from - * a printk(). This function spins until all data is written. - * - * We copy the data to a temporary buffer because we need to insert a \r in - * front of every \n. It's more efficient to copy the data to the buffer than - * it is to make multiple hcalls for each character or each newline. - */ -static void ehv_bc_console_write(struct console *co, const char *s, - unsigned int count) -{ - char s2[EV_BYTE_CHANNEL_MAX_BYTES]; - unsigned int i, j = 0; - char c; - - for (i = 0; i < count; i++) { - c = *s++; - - if (c == '\n') - s2[j++] = '\r'; - - s2[j++] = c; - if (j >= (EV_BYTE_CHANNEL_MAX_BYTES - 1)) { - if (ehv_bc_console_byte_channel_send(stdout_bc, s2, j)) - return; - j = 0; - } - } - - if (j) - ehv_bc_console_byte_channel_send(stdout_bc, s2, j); -} - -/* - * When /dev/console is opened, the kernel iterates the console list looking - * for one with ->device and then calls that method. On success, it expects - * the passed-in int* to contain the minor number to use. - */ -static struct tty_driver *ehv_bc_console_device(struct console *co, int *index) -{ - *index = co->index; - - return ehv_bc_driver; -} - -static struct console ehv_bc_console = { - .name = "ttyEHV", - .write = ehv_bc_console_write, - .device = ehv_bc_console_device, - .flags = CON_PRINTBUFFER | CON_ENABLED, -}; - -/* - * Console initialization - * - * This is the first function that is called after the device tree is - * available, so here is where we determine the byte channel handle and IRQ for - * stdout/stdin, even though that information is used by the tty and character - * drivers. - */ -static int __init ehv_bc_console_init(void) -{ - if (!find_console_handle()) { - pr_debug("ehv-bc: stdout is not a byte channel\n"); - return -ENODEV; - } - -#ifdef CONFIG_PPC_EARLY_DEBUG_EHV_BC - /* Print a friendly warning if the user chose the wrong byte channel - * handle for udbg. - */ - if (stdout_bc != CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE) - pr_warning("ehv-bc: udbg handle %u is not the stdout handle\n", - CONFIG_PPC_EARLY_DEBUG_EHV_BC_HANDLE); -#endif - - /* add_preferred_console() must be called before register_console(), - otherwise it won't work. However, we don't want to enumerate all the - byte channels here, either, since we only care about one. */ - - add_preferred_console(ehv_bc_console.name, ehv_bc_console.index, NULL); - register_console(&ehv_bc_console); - - pr_info("ehv-bc: registered console driver for byte channel %u\n", - stdout_bc); - - return 0; -} -console_initcall(ehv_bc_console_init); - -/******************************** TTY DRIVER ********************************/ - -/* - * byte channel receive interupt handler - * - * This ISR is called whenever data is available on a byte channel. - */ -static irqreturn_t ehv_bc_tty_rx_isr(int irq, void *data) -{ - struct ehv_bc_data *bc = data; - struct tty_struct *ttys = tty_port_tty_get(&bc->port); - unsigned int rx_count, tx_count, len; - int count; - char buffer[EV_BYTE_CHANNEL_MAX_BYTES]; - int ret; - - /* ttys could be NULL during a hangup */ - if (!ttys) - return IRQ_HANDLED; - - /* Find out how much data needs to be read, and then ask the TTY layer - * if it can handle that much. We want to ensure that every byte we - * read from the byte channel will be accepted by the TTY layer. - */ - ev_byte_channel_poll(bc->handle, &rx_count, &tx_count); - count = tty_buffer_request_room(ttys, rx_count); - - /* 'count' is the maximum amount of data the TTY layer can accept at - * this time. However, during testing, I was never able to get 'count' - * to be less than 'rx_count'. I'm not sure whether I'm calling it - * correctly. - */ - - while (count > 0) { - len = min_t(unsigned int, count, sizeof(buffer)); - - /* Read some data from the byte channel. This function will - * never return more than EV_BYTE_CHANNEL_MAX_BYTES bytes. - */ - ev_byte_channel_receive(bc->handle, &len, buffer); - - /* 'len' is now the amount of data that's been received. 'len' - * can't be zero, and most likely it's equal to one. - */ - - /* Pass the received data to the tty layer. */ - ret = tty_insert_flip_string(ttys, buffer, len); - - /* 'ret' is the number of bytes that the TTY layer accepted. - * If it's not equal to 'len', then it means the buffer is - * full, which should never happen. If it does happen, we can - * exit gracefully, but we drop the last 'len - ret' characters - * that we read from the byte channel. - */ - if (ret != len) - break; - - count -= len; - } - - /* Tell the tty layer that we're done. */ - tty_flip_buffer_push(ttys); - - tty_kref_put(ttys); - - return IRQ_HANDLED; -} - -/* - * dequeue the transmit buffer to the hypervisor - * - * This function, which can be called in interrupt context, dequeues as much - * data as possible from the transmit buffer to the byte channel. - */ -static void ehv_bc_tx_dequeue(struct ehv_bc_data *bc) -{ - unsigned int count; - unsigned int len, ret; - unsigned long flags; - - do { - spin_lock_irqsave(&bc->lock, flags); - len = min_t(unsigned int, - CIRC_CNT_TO_END(bc->head, bc->tail, BUF_SIZE), - EV_BYTE_CHANNEL_MAX_BYTES); - - ret = ev_byte_channel_send(bc->handle, &len, bc->buf + bc->tail); - - /* 'len' is valid only if the return code is 0 or EV_EAGAIN */ - if (!ret || (ret == EV_EAGAIN)) - bc->tail = (bc->tail + len) & (BUF_SIZE - 1); - - count = CIRC_CNT(bc->head, bc->tail, BUF_SIZE); - spin_unlock_irqrestore(&bc->lock, flags); - } while (count && !ret); - - spin_lock_irqsave(&bc->lock, flags); - if (CIRC_CNT(bc->head, bc->tail, BUF_SIZE)) - /* - * If we haven't emptied the buffer, then enable the TX IRQ. - * We'll get an interrupt when there's more room in the - * hypervisor's output buffer. - */ - enable_tx_interrupt(bc); - else - disable_tx_interrupt(bc); - spin_unlock_irqrestore(&bc->lock, flags); -} - -/* - * byte channel transmit interupt handler - * - * This ISR is called whenever space becomes available for transmitting - * characters on a byte channel. - */ -static irqreturn_t ehv_bc_tty_tx_isr(int irq, void *data) -{ - struct ehv_bc_data *bc = data; - struct tty_struct *ttys = tty_port_tty_get(&bc->port); - - ehv_bc_tx_dequeue(bc); - if (ttys) { - tty_wakeup(ttys); - tty_kref_put(ttys); - } - - return IRQ_HANDLED; -} - -/* - * This function is called when the tty layer has data for us send. We store - * the data first in a circular buffer, and then dequeue as much of that data - * as possible. - * - * We don't need to worry about whether there is enough room in the buffer for - * all the data. The purpose of ehv_bc_tty_write_room() is to tell the tty - * layer how much data it can safely send to us. We guarantee that - * ehv_bc_tty_write_room() will never lie, so the tty layer will never send us - * too much data. - */ -static int ehv_bc_tty_write(struct tty_struct *ttys, const unsigned char *s, - int count) -{ - struct ehv_bc_data *bc = ttys->driver_data; - unsigned long flags; - unsigned int len; - unsigned int written = 0; - - while (1) { - spin_lock_irqsave(&bc->lock, flags); - len = CIRC_SPACE_TO_END(bc->head, bc->tail, BUF_SIZE); - if (count < len) - len = count; - if (len) { - memcpy(bc->buf + bc->head, s, len); - bc->head = (bc->head + len) & (BUF_SIZE - 1); - } - spin_unlock_irqrestore(&bc->lock, flags); - if (!len) - break; - - s += len; - count -= len; - written += len; - } - - ehv_bc_tx_dequeue(bc); - - return written; -} - -/* - * This function can be called multiple times for a given tty_struct, which is - * why we initialize bc->ttys in ehv_bc_tty_port_activate() instead. - * - * The tty layer will still call this function even if the device was not - * registered (i.e. tty_register_device() was not called). This happens - * because tty_register_device() is optional and some legacy drivers don't - * use it. So we need to check for that. - */ -static int ehv_bc_tty_open(struct tty_struct *ttys, struct file *filp) -{ - struct ehv_bc_data *bc = &bcs[ttys->index]; - - if (!bc->dev) - return -ENODEV; - - return tty_port_open(&bc->port, ttys, filp); -} - -/* - * Amazingly, if ehv_bc_tty_open() returns an error code, the tty layer will - * still call this function to close the tty device. So we can't assume that - * the tty port has been initialized. - */ -static void ehv_bc_tty_close(struct tty_struct *ttys, struct file *filp) -{ - struct ehv_bc_data *bc = &bcs[ttys->index]; - - if (bc->dev) - tty_port_close(&bc->port, ttys, filp); -} - -/* - * Return the amount of space in the output buffer - * - * This is actually a contract between the driver and the tty layer outlining - * how much write room the driver can guarantee will be sent OR BUFFERED. This - * driver MUST honor the return value. - */ -static int ehv_bc_tty_write_room(struct tty_struct *ttys) -{ - struct ehv_bc_data *bc = ttys->driver_data; - unsigned long flags; - int count; - - spin_lock_irqsave(&bc->lock, flags); - count = CIRC_SPACE(bc->head, bc->tail, BUF_SIZE); - spin_unlock_irqrestore(&bc->lock, flags); - - return count; -} - -/* - * Stop sending data to the tty layer - * - * This function is called when the tty layer's input buffers are getting full, - * so the driver should stop sending it data. The easiest way to do this is to - * disable the RX IRQ, which will prevent ehv_bc_tty_rx_isr() from being - * called. - * - * The hypervisor will continue to queue up any incoming data. If there is any - * data in the queue when the RX interrupt is enabled, we'll immediately get an - * RX interrupt. - */ -static void ehv_bc_tty_throttle(struct tty_struct *ttys) -{ - struct ehv_bc_data *bc = ttys->driver_data; - - disable_irq(bc->rx_irq); -} - -/* - * Resume sending data to the tty layer - * - * This function is called after previously calling ehv_bc_tty_throttle(). The - * tty layer's input buffers now have more room, so the driver can resume - * sending it data. - */ -static void ehv_bc_tty_unthrottle(struct tty_struct *ttys) -{ - struct ehv_bc_data *bc = ttys->driver_data; - - /* If there is any data in the queue when the RX interrupt is enabled, - * we'll immediately get an RX interrupt. - */ - enable_irq(bc->rx_irq); -} - -static void ehv_bc_tty_hangup(struct tty_struct *ttys) -{ - struct ehv_bc_data *bc = ttys->driver_data; - - ehv_bc_tx_dequeue(bc); - tty_port_hangup(&bc->port); -} - -/* - * TTY driver operations - * - * If we could ask the hypervisor how much data is still in the TX buffer, or - * at least how big the TX buffers are, then we could implement the - * .wait_until_sent and .chars_in_buffer functions. - */ -static const struct tty_operations ehv_bc_ops = { - .open = ehv_bc_tty_open, - .close = ehv_bc_tty_close, - .write = ehv_bc_tty_write, - .write_room = ehv_bc_tty_write_room, - .throttle = ehv_bc_tty_throttle, - .unthrottle = ehv_bc_tty_unthrottle, - .hangup = ehv_bc_tty_hangup, -}; - -/* - * initialize the TTY port - * - * This function will only be called once, no matter how many times - * ehv_bc_tty_open() is called. That's why we register the ISR here, and also - * why we initialize tty_struct-related variables here. - */ -static int ehv_bc_tty_port_activate(struct tty_port *port, - struct tty_struct *ttys) -{ - struct ehv_bc_data *bc = container_of(port, struct ehv_bc_data, port); - int ret; - - ttys->driver_data = bc; - - ret = request_irq(bc->rx_irq, ehv_bc_tty_rx_isr, 0, "ehv-bc", bc); - if (ret < 0) { - dev_err(bc->dev, "could not request rx irq %u (ret=%i)\n", - bc->rx_irq, ret); - return ret; - } - - /* request_irq also enables the IRQ */ - bc->tx_irq_enabled = 1; - - ret = request_irq(bc->tx_irq, ehv_bc_tty_tx_isr, 0, "ehv-bc", bc); - if (ret < 0) { - dev_err(bc->dev, "could not request tx irq %u (ret=%i)\n", - bc->tx_irq, ret); - free_irq(bc->rx_irq, bc); - return ret; - } - - /* The TX IRQ is enabled only when we can't write all the data to the - * byte channel at once, so by default it's disabled. - */ - disable_tx_interrupt(bc); - - return 0; -} - -static void ehv_bc_tty_port_shutdown(struct tty_port *port) -{ - struct ehv_bc_data *bc = container_of(port, struct ehv_bc_data, port); - - free_irq(bc->tx_irq, bc); - free_irq(bc->rx_irq, bc); -} - -static const struct tty_port_operations ehv_bc_tty_port_ops = { - .activate = ehv_bc_tty_port_activate, - .shutdown = ehv_bc_tty_port_shutdown, -}; - -static int __devinit ehv_bc_tty_probe(struct platform_device *pdev) -{ - struct device_node *np = pdev->dev.of_node; - struct ehv_bc_data *bc; - const uint32_t *iprop; - unsigned int handle; - int ret; - static unsigned int index = 1; - unsigned int i; - - iprop = of_get_property(np, "hv-handle", NULL); - if (!iprop) { - dev_err(&pdev->dev, "no 'hv-handle' property in %s node\n", - np->name); - return -ENODEV; - } - - /* We already told the console layer that the index for the console - * device is zero, so we need to make sure that we use that index when - * we probe the console byte channel node. - */ - handle = be32_to_cpu(*iprop); - i = (handle == stdout_bc) ? 0 : index++; - bc = &bcs[i]; - - bc->handle = handle; - bc->head = 0; - bc->tail = 0; - spin_lock_init(&bc->lock); - - bc->rx_irq = irq_of_parse_and_map(np, 0); - bc->tx_irq = irq_of_parse_and_map(np, 1); - if ((bc->rx_irq == NO_IRQ) || (bc->tx_irq == NO_IRQ)) { - dev_err(&pdev->dev, "no 'interrupts' property in %s node\n", - np->name); - ret = -ENODEV; - goto error; - } - - bc->dev = tty_register_device(ehv_bc_driver, i, &pdev->dev); - if (IS_ERR(bc->dev)) { - ret = PTR_ERR(bc->dev); - dev_err(&pdev->dev, "could not register tty (ret=%i)\n", ret); - goto error; - } - - tty_port_init(&bc->port); - bc->port.ops = &ehv_bc_tty_port_ops; - - dev_set_drvdata(&pdev->dev, bc); - - dev_info(&pdev->dev, "registered /dev/%s%u for byte channel %u\n", - ehv_bc_driver->name, i, bc->handle); - - return 0; - -error: - irq_dispose_mapping(bc->tx_irq); - irq_dispose_mapping(bc->rx_irq); - - memset(bc, 0, sizeof(struct ehv_bc_data)); - return ret; -} - -static int ehv_bc_tty_remove(struct platform_device *pdev) -{ - struct ehv_bc_data *bc = dev_get_drvdata(&pdev->dev); - - tty_unregister_device(ehv_bc_driver, bc - bcs); - - irq_dispose_mapping(bc->tx_irq); - irq_dispose_mapping(bc->rx_irq); - - return 0; -} - -static const struct of_device_id ehv_bc_tty_of_ids[] = { - { .compatible = "epapr,hv-byte-channel" }, - {} -}; - -static struct platform_driver ehv_bc_tty_driver = { - .driver = { - .owner = THIS_MODULE, - .name = "ehv-bc", - .of_match_table = ehv_bc_tty_of_ids, - }, - .probe = ehv_bc_tty_probe, - .remove = ehv_bc_tty_remove, -}; - -/** - * ehv_bc_init - ePAPR hypervisor byte channel driver initialization - * - * This function is called when this module is loaded. - */ -static int __init ehv_bc_init(void) -{ - struct device_node *np; - unsigned int count = 0; /* Number of elements in bcs[] */ - int ret; - - pr_info("ePAPR hypervisor byte channel driver\n"); - - /* Count the number of byte channels */ - for_each_compatible_node(np, NULL, "epapr,hv-byte-channel") - count++; - - if (!count) - return -ENODEV; - - /* The array index of an element in bcs[] is the same as the tty index - * for that element. If you know the address of an element in the - * array, then you can use pointer math (e.g. "bc - bcs") to get its - * tty index. - */ - bcs = kzalloc(count * sizeof(struct ehv_bc_data), GFP_KERNEL); - if (!bcs) - return -ENOMEM; - - ehv_bc_driver = alloc_tty_driver(count); - if (!ehv_bc_driver) { - ret = -ENOMEM; - goto error; - } - - ehv_bc_driver->driver_name = "ehv-bc"; - ehv_bc_driver->name = ehv_bc_console.name; - ehv_bc_driver->type = TTY_DRIVER_TYPE_CONSOLE; - ehv_bc_driver->subtype = SYSTEM_TYPE_CONSOLE; - ehv_bc_driver->init_termios = tty_std_termios; - ehv_bc_driver->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; - tty_set_operations(ehv_bc_driver, &ehv_bc_ops); - - ret = tty_register_driver(ehv_bc_driver); - if (ret) { - pr_err("ehv-bc: could not register tty driver (ret=%i)\n", ret); - goto error; - } - - ret = platform_driver_register(&ehv_bc_tty_driver); - if (ret) { - pr_err("ehv-bc: could not register platform driver (ret=%i)\n", - ret); - goto error; - } - - return 0; - -error: - if (ehv_bc_driver) { - tty_unregister_driver(ehv_bc_driver); - put_tty_driver(ehv_bc_driver); - } - - kfree(bcs); - - return ret; -} - - -/** - * ehv_bc_exit - ePAPR hypervisor byte channel driver termination - * - * This function is called when this driver is unloaded. - */ -static void __exit ehv_bc_exit(void) -{ - tty_unregister_driver(ehv_bc_driver); - put_tty_driver(ehv_bc_driver); - kfree(bcs); -} - -module_init(ehv_bc_init); -module_exit(ehv_bc_exit); - -MODULE_AUTHOR("Timur Tabi <timur@freescale.com>"); -MODULE_DESCRIPTION("ePAPR hypervisor byte channel driver"); -MODULE_LICENSE("GPL v2"); |