+++ /dev/null
-/*
- * TTY over Blackfin JTAG Communication
- *
- * Copyright 2008-2009 Analog Devices Inc.
- *
- * Enter bugs at http://blackfin.uclinux.org/
- *
- * Licensed under the GPL-2 or later.
- */
-
-#define DRV_NAME "bfin-jtag-comm"
-#define DEV_NAME "ttyBFJC"
-#define pr_fmt(fmt) DRV_NAME ": " fmt
-
-#include <linux/circ_buf.h>
-#include <linux/console.h>
-#include <linux/delay.h>
-#include <linux/err.h>
-#include <linux/kernel.h>
-#include <linux/kthread.h>
-#include <linux/module.h>
-#include <linux/mutex.h>
-#include <linux/sched.h>
-#include <linux/slab.h>
-#include <linux/tty.h>
-#include <linux/tty_driver.h>
-#include <linux/tty_flip.h>
-#include <asm/atomic.h>
-
-#define pr_init(fmt, args...) ({ static const __initconst char __fmt[] = fmt; printk(__fmt, ## args); })
-
-/* See the Debug/Emulation chapter in the HRM */
-#define EMUDOF 0x00000001 /* EMUDAT_OUT full & valid */
-#define EMUDIF 0x00000002 /* EMUDAT_IN full & valid */
-#define EMUDOOVF 0x00000004 /* EMUDAT_OUT overflow */
-#define EMUDIOVF 0x00000008 /* EMUDAT_IN overflow */
-
-static inline uint32_t bfin_write_emudat(uint32_t emudat)
-{
- __asm__ __volatile__("emudat = %0;" : : "d"(emudat));
- return emudat;
-}
-
-static inline uint32_t bfin_read_emudat(void)
-{
- uint32_t emudat;
- __asm__ __volatile__("%0 = emudat;" : "=d"(emudat));
- return emudat;
-}
-
-static inline uint32_t bfin_write_emudat_chars(char a, char b, char c, char d)
-{
- return bfin_write_emudat((a << 0) | (b << 8) | (c << 16) | (d << 24));
-}
-
-#define CIRC_SIZE 2048 /* see comment in tty_io.c:do_tty_write() */
-#define CIRC_MASK (CIRC_SIZE - 1)
-#define circ_empty(circ) ((circ)->head == (circ)->tail)
-#define circ_free(circ) CIRC_SPACE((circ)->head, (circ)->tail, CIRC_SIZE)
-#define circ_cnt(circ) CIRC_CNT((circ)->head, (circ)->tail, CIRC_SIZE)
-#define circ_byte(circ, idx) ((circ)->buf[(idx) & CIRC_MASK])
-
-static struct tty_driver *bfin_jc_driver;
-static struct task_struct *bfin_jc_kthread;
-static struct tty_struct * volatile bfin_jc_tty;
-static unsigned long bfin_jc_count;
-static DEFINE_MUTEX(bfin_jc_tty_mutex);
-static volatile struct circ_buf bfin_jc_write_buf;
-
-static int
-bfin_jc_emudat_manager(void *arg)
-{
- uint32_t inbound_len = 0, outbound_len = 0;
-
- while (!kthread_should_stop()) {
- /* no one left to give data to, so sleep */
- if (bfin_jc_tty == NULL && circ_empty(&bfin_jc_write_buf)) {
- pr_debug("waiting for readers\n");
- __set_current_state(TASK_UNINTERRUPTIBLE);
- schedule();
- __set_current_state(TASK_RUNNING);
- }
-
- /* no data available, so just chill */
- if (!(bfin_read_DBGSTAT() & EMUDIF) && circ_empty(&bfin_jc_write_buf)) {
- pr_debug("waiting for data (in_len = %i) (circ: %i %i)\n",
- inbound_len, bfin_jc_write_buf.tail, bfin_jc_write_buf.head);
- if (inbound_len)
- schedule();
- else
- schedule_timeout_interruptible(HZ);
- continue;
- }
-
- /* if incoming data is ready, eat it */
- if (bfin_read_DBGSTAT() & EMUDIF) {
- struct tty_struct *tty;
- mutex_lock(&bfin_jc_tty_mutex);
- tty = (struct tty_struct *)bfin_jc_tty;
- if (tty != NULL) {
- uint32_t emudat = bfin_read_emudat();
- if (inbound_len == 0) {
- pr_debug("incoming length: 0x%08x\n", emudat);
- inbound_len = emudat;
- } else {
- size_t num_chars = (4 <= inbound_len ? 4 : inbound_len);
- pr_debug(" incoming data: 0x%08x (pushing %zu)\n", emudat, num_chars);
- inbound_len -= num_chars;
- tty_insert_flip_string(tty, (unsigned char *)&emudat, num_chars);
- tty_flip_buffer_push(tty);
- }
- }
- mutex_unlock(&bfin_jc_tty_mutex);
- }
-
- /* if outgoing data is ready, post it */
- if (!(bfin_read_DBGSTAT() & EMUDOF) && !circ_empty(&bfin_jc_write_buf)) {
- if (outbound_len == 0) {
- outbound_len = circ_cnt(&bfin_jc_write_buf);
- bfin_write_emudat(outbound_len);
- pr_debug("outgoing length: 0x%08x\n", outbound_len);
- } else {
- struct tty_struct *tty;
- int tail = bfin_jc_write_buf.tail;
- size_t ate = (4 <= outbound_len ? 4 : outbound_len);
- uint32_t emudat =
- bfin_write_emudat_chars(
- circ_byte(&bfin_jc_write_buf, tail + 0),
- circ_byte(&bfin_jc_write_buf, tail + 1),
- circ_byte(&bfin_jc_write_buf, tail + 2),
- circ_byte(&bfin_jc_write_buf, tail + 3)
- );
- bfin_jc_write_buf.tail += ate;
- outbound_len -= ate;
- mutex_lock(&bfin_jc_tty_mutex);
- tty = (struct tty_struct *)bfin_jc_tty;
- if (tty)
- tty_wakeup(tty);
- mutex_unlock(&bfin_jc_tty_mutex);
- pr_debug(" outgoing data: 0x%08x (pushing %zu)\n", emudat, ate);
- }
- }
- }
-
- __set_current_state(TASK_RUNNING);
- return 0;
-}
-
-static int
-bfin_jc_open(struct tty_struct *tty, struct file *filp)
-{
- mutex_lock(&bfin_jc_tty_mutex);
- pr_debug("open %lu\n", bfin_jc_count);
- ++bfin_jc_count;
- bfin_jc_tty = tty;
- wake_up_process(bfin_jc_kthread);
- mutex_unlock(&bfin_jc_tty_mutex);
- return 0;
-}
-
-static void
-bfin_jc_close(struct tty_struct *tty, struct file *filp)
-{
- mutex_lock(&bfin_jc_tty_mutex);
- pr_debug("close %lu\n", bfin_jc_count);
- if (--bfin_jc_count == 0)
- bfin_jc_tty = NULL;
- wake_up_process(bfin_jc_kthread);
- mutex_unlock(&bfin_jc_tty_mutex);
-}
-
-/* XXX: we dont handle the put_char() case where we must handle count = 1 */
-static int
-bfin_jc_circ_write(const unsigned char *buf, int count)
-{
- int i;
- count = min(count, circ_free(&bfin_jc_write_buf));
- pr_debug("going to write chunk of %i bytes\n", count);
- for (i = 0; i < count; ++i)
- circ_byte(&bfin_jc_write_buf, bfin_jc_write_buf.head + i) = buf[i];
- bfin_jc_write_buf.head += i;
- return i;
-}
-
-#ifndef CONFIG_BFIN_JTAG_COMM_CONSOLE
-# define console_lock()
-# define console_unlock()
-#endif
-static int
-bfin_jc_write(struct tty_struct *tty, const unsigned char *buf, int count)
-{
- int i;
- console_lock();
- i = bfin_jc_circ_write(buf, count);
- console_unlock();
- wake_up_process(bfin_jc_kthread);
- return i;
-}
-
-static void
-bfin_jc_flush_chars(struct tty_struct *tty)
-{
- wake_up_process(bfin_jc_kthread);
-}
-
-static int
-bfin_jc_write_room(struct tty_struct *tty)
-{
- return circ_free(&bfin_jc_write_buf);
-}
-
-static int
-bfin_jc_chars_in_buffer(struct tty_struct *tty)
-{
- return circ_cnt(&bfin_jc_write_buf);
-}
-
-static void
-bfin_jc_wait_until_sent(struct tty_struct *tty, int timeout)
-{
- unsigned long expire = jiffies + timeout;
- while (!circ_empty(&bfin_jc_write_buf)) {
- if (signal_pending(current))
- break;
- if (time_after(jiffies, expire))
- break;
- }
-}
-
-static const struct tty_operations bfin_jc_ops = {
- .open = bfin_jc_open,
- .close = bfin_jc_close,
- .write = bfin_jc_write,
- /*.put_char = bfin_jc_put_char,*/
- .flush_chars = bfin_jc_flush_chars,
- .write_room = bfin_jc_write_room,
- .chars_in_buffer = bfin_jc_chars_in_buffer,
- .wait_until_sent = bfin_jc_wait_until_sent,
-};
-
-static int __init bfin_jc_init(void)
-{
- int ret;
-
- bfin_jc_kthread = kthread_create(bfin_jc_emudat_manager, NULL, DRV_NAME);
- if (IS_ERR(bfin_jc_kthread))
- return PTR_ERR(bfin_jc_kthread);
-
- ret = -ENOMEM;
-
- bfin_jc_write_buf.head = bfin_jc_write_buf.tail = 0;
- bfin_jc_write_buf.buf = kmalloc(CIRC_SIZE, GFP_KERNEL);
- if (!bfin_jc_write_buf.buf)
- goto err;
-
- bfin_jc_driver = alloc_tty_driver(1);
- if (!bfin_jc_driver)
- goto err;
-
- bfin_jc_driver->owner = THIS_MODULE;
- bfin_jc_driver->driver_name = DRV_NAME;
- bfin_jc_driver->name = DEV_NAME;
- bfin_jc_driver->type = TTY_DRIVER_TYPE_SERIAL;
- bfin_jc_driver->subtype = SERIAL_TYPE_NORMAL;
- bfin_jc_driver->init_termios = tty_std_termios;
- tty_set_operations(bfin_jc_driver, &bfin_jc_ops);
-
- ret = tty_register_driver(bfin_jc_driver);
- if (ret)
- goto err;
-
- pr_init(KERN_INFO DRV_NAME ": initialized\n");
-
- return 0;
-
- err:
- put_tty_driver(bfin_jc_driver);
- kfree(bfin_jc_write_buf.buf);
- kthread_stop(bfin_jc_kthread);
- return ret;
-}
-module_init(bfin_jc_init);
-
-static void __exit bfin_jc_exit(void)
-{
- kthread_stop(bfin_jc_kthread);
- kfree(bfin_jc_write_buf.buf);
- tty_unregister_driver(bfin_jc_driver);
- put_tty_driver(bfin_jc_driver);
-}
-module_exit(bfin_jc_exit);
-
-#if defined(CONFIG_BFIN_JTAG_COMM_CONSOLE) || defined(CONFIG_EARLY_PRINTK)
-static void
-bfin_jc_straight_buffer_write(const char *buf, unsigned count)
-{
- unsigned ate = 0;
- while (bfin_read_DBGSTAT() & EMUDOF)
- continue;
- bfin_write_emudat(count);
- while (ate < count) {
- while (bfin_read_DBGSTAT() & EMUDOF)
- continue;
- bfin_write_emudat_chars(buf[ate], buf[ate+1], buf[ate+2], buf[ate+3]);
- ate += 4;
- }
-}
-#endif
-
-#ifdef CONFIG_BFIN_JTAG_COMM_CONSOLE
-static void
-bfin_jc_console_write(struct console *co, const char *buf, unsigned count)
-{
- if (bfin_jc_kthread == NULL)
- bfin_jc_straight_buffer_write(buf, count);
- else
- bfin_jc_circ_write(buf, count);
-}
-
-static struct tty_driver *
-bfin_jc_console_device(struct console *co, int *index)
-{
- *index = co->index;
- return bfin_jc_driver;
-}
-
-static struct console bfin_jc_console = {
- .name = DEV_NAME,
- .write = bfin_jc_console_write,
- .device = bfin_jc_console_device,
- .flags = CON_ANYTIME | CON_PRINTBUFFER,
- .index = -1,
-};
-
-static int __init bfin_jc_console_init(void)
-{
- register_console(&bfin_jc_console);
- return 0;
-}
-console_initcall(bfin_jc_console_init);
-#endif
-
-#ifdef CONFIG_EARLY_PRINTK
-static void __init
-bfin_jc_early_write(struct console *co, const char *buf, unsigned int count)
-{
- bfin_jc_straight_buffer_write(buf, count);
-}
-
-static struct __initdata console bfin_jc_early_console = {
- .name = "early_BFJC",
- .write = bfin_jc_early_write,
- .flags = CON_ANYTIME | CON_PRINTBUFFER,
- .index = -1,
-};
-
-struct console * __init
-bfin_jc_early_init(unsigned int port, unsigned int cflag)
-{
- return &bfin_jc_early_console;
-}
-#endif
-
-MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
-MODULE_DESCRIPTION("TTY over Blackfin JTAG Communication");
-MODULE_LICENSE("GPL");
git.openpandora.org / pandora-kernel.git / blobdiff