From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- drivers/misc/bcm-vk/bcm_vk_tty.c | 339 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 339 insertions(+) create mode 100644 drivers/misc/bcm-vk/bcm_vk_tty.c (limited to 'drivers/misc/bcm-vk/bcm_vk_tty.c') diff --git a/drivers/misc/bcm-vk/bcm_vk_tty.c b/drivers/misc/bcm-vk/bcm_vk_tty.c new file mode 100644 index 000000000..6669625ba --- /dev/null +++ b/drivers/misc/bcm-vk/bcm_vk_tty.c @@ -0,0 +1,339 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2018-2020 Broadcom. + */ + +#include +#include +#include + +#include "bcm_vk.h" + +/* TTYVK base offset is 0x30000 into BAR1 */ +#define BAR1_TTYVK_BASE_OFFSET 0x300000 +/* Each TTYVK channel (TO or FROM) is 0x10000 */ +#define BAR1_TTYVK_CHAN_OFFSET 0x100000 +/* Each TTYVK channel has TO and FROM, hence the * 2 */ +#define BAR1_TTYVK_BASE(index) (BAR1_TTYVK_BASE_OFFSET + \ + ((index) * BAR1_TTYVK_CHAN_OFFSET * 2)) +/* TO TTYVK channel base comes before FROM for each index */ +#define TO_TTYK_BASE(index) BAR1_TTYVK_BASE(index) +#define FROM_TTYK_BASE(index) (BAR1_TTYVK_BASE(index) + \ + BAR1_TTYVK_CHAN_OFFSET) + +struct bcm_vk_tty_chan { + u32 reserved; + u32 size; + u32 wr; + u32 rd; + u32 *data; +}; + +#define VK_BAR_CHAN(v, DIR, e) ((v)->DIR##_offset \ + + offsetof(struct bcm_vk_tty_chan, e)) +#define VK_BAR_CHAN_SIZE(v, DIR) VK_BAR_CHAN(v, DIR, size) +#define VK_BAR_CHAN_WR(v, DIR) VK_BAR_CHAN(v, DIR, wr) +#define VK_BAR_CHAN_RD(v, DIR) VK_BAR_CHAN(v, DIR, rd) +#define VK_BAR_CHAN_DATA(v, DIR, off) (VK_BAR_CHAN(v, DIR, data) + (off)) + +#define VK_BAR0_REGSEG_TTY_DB_OFFSET 0x86c + +/* Poll every 1/10 of second - temp hack till we use MSI interrupt */ +#define SERIAL_TIMER_VALUE (HZ / 10) + +static void bcm_vk_tty_poll(struct timer_list *t) +{ + struct bcm_vk *vk = from_timer(vk, t, serial_timer); + + queue_work(vk->tty_wq_thread, &vk->tty_wq_work); + mod_timer(&vk->serial_timer, jiffies + SERIAL_TIMER_VALUE); +} + +irqreturn_t bcm_vk_tty_irqhandler(int irq, void *dev_id) +{ + struct bcm_vk *vk = dev_id; + + queue_work(vk->tty_wq_thread, &vk->tty_wq_work); + + return IRQ_HANDLED; +} + +static void bcm_vk_tty_wq_handler(struct work_struct *work) +{ + struct bcm_vk *vk = container_of(work, struct bcm_vk, tty_wq_work); + struct bcm_vk_tty *vktty; + int card_status; + int count; + unsigned char c; + int i; + int wr; + + card_status = vkread32(vk, BAR_0, BAR_CARD_STATUS); + if (BCM_VK_INTF_IS_DOWN(card_status)) + return; + + for (i = 0; i < BCM_VK_NUM_TTY; i++) { + count = 0; + /* Check the card status that the tty channel is ready */ + if ((card_status & BIT(i)) == 0) + continue; + + vktty = &vk->tty[i]; + + /* Don't increment read index if tty app is closed */ + if (!vktty->is_opened) + continue; + + /* Fetch the wr offset in buffer from VK */ + wr = vkread32(vk, BAR_1, VK_BAR_CHAN_WR(vktty, from)); + + /* safe to ignore until bar read gives proper size */ + if (vktty->from_size == 0) + continue; + + if (wr >= vktty->from_size) { + dev_err(&vk->pdev->dev, + "ERROR: wq handler ttyVK%d wr:0x%x > 0x%x\n", + i, wr, vktty->from_size); + /* Need to signal and close device in this case */ + continue; + } + + /* + * Simple read of circular buffer and + * insert into tty flip buffer + */ + while (vk->tty[i].rd != wr) { + c = vkread8(vk, BAR_1, + VK_BAR_CHAN_DATA(vktty, from, vktty->rd)); + vktty->rd++; + if (vktty->rd >= vktty->from_size) + vktty->rd = 0; + tty_insert_flip_char(&vktty->port, c, TTY_NORMAL); + count++; + } + + if (count) { + tty_flip_buffer_push(&vktty->port); + + /* Update read offset from shadow register to card */ + vkwrite32(vk, vktty->rd, BAR_1, + VK_BAR_CHAN_RD(vktty, from)); + } + } +} + +static int bcm_vk_tty_open(struct tty_struct *tty, struct file *file) +{ + int card_status; + struct bcm_vk *vk; + struct bcm_vk_tty *vktty; + int index; + + /* initialize the pointer in case something fails */ + tty->driver_data = NULL; + + vk = (struct bcm_vk *)dev_get_drvdata(tty->dev); + index = tty->index; + + if (index >= BCM_VK_NUM_TTY) + return -EINVAL; + + vktty = &vk->tty[index]; + + vktty->pid = task_pid_nr(current); + vktty->to_offset = TO_TTYK_BASE(index); + vktty->from_offset = FROM_TTYK_BASE(index); + + /* Do not allow tty device to be opened if tty on card not ready */ + card_status = vkread32(vk, BAR_0, BAR_CARD_STATUS); + if (BCM_VK_INTF_IS_DOWN(card_status) || ((card_status & BIT(index)) == 0)) + return -EBUSY; + + /* + * Get shadow registers of the buffer sizes and the "to" write offset + * and "from" read offset + */ + vktty->to_size = vkread32(vk, BAR_1, VK_BAR_CHAN_SIZE(vktty, to)); + vktty->wr = vkread32(vk, BAR_1, VK_BAR_CHAN_WR(vktty, to)); + vktty->from_size = vkread32(vk, BAR_1, VK_BAR_CHAN_SIZE(vktty, from)); + vktty->rd = vkread32(vk, BAR_1, VK_BAR_CHAN_RD(vktty, from)); + vktty->is_opened = true; + + if (tty->count == 1 && !vktty->irq_enabled) { + timer_setup(&vk->serial_timer, bcm_vk_tty_poll, 0); + mod_timer(&vk->serial_timer, jiffies + SERIAL_TIMER_VALUE); + } + return 0; +} + +static void bcm_vk_tty_close(struct tty_struct *tty, struct file *file) +{ + struct bcm_vk *vk = dev_get_drvdata(tty->dev); + + if (tty->index >= BCM_VK_NUM_TTY) + return; + + vk->tty[tty->index].is_opened = false; + + if (tty->count == 1) + del_timer_sync(&vk->serial_timer); +} + +static void bcm_vk_tty_doorbell(struct bcm_vk *vk, u32 db_val) +{ + vkwrite32(vk, db_val, BAR_0, + VK_BAR0_REGSEG_DB_BASE + VK_BAR0_REGSEG_TTY_DB_OFFSET); +} + +static int bcm_vk_tty_write(struct tty_struct *tty, + const unsigned char *buffer, + int count) +{ + int index; + struct bcm_vk *vk; + struct bcm_vk_tty *vktty; + int i; + + index = tty->index; + vk = dev_get_drvdata(tty->dev); + vktty = &vk->tty[index]; + + /* Simple write each byte to circular buffer */ + for (i = 0; i < count; i++) { + vkwrite8(vk, buffer[i], BAR_1, + VK_BAR_CHAN_DATA(vktty, to, vktty->wr)); + vktty->wr++; + if (vktty->wr >= vktty->to_size) + vktty->wr = 0; + } + /* Update write offset from shadow register to card */ + vkwrite32(vk, vktty->wr, BAR_1, VK_BAR_CHAN_WR(vktty, to)); + bcm_vk_tty_doorbell(vk, 0); + + return count; +} + +static unsigned int bcm_vk_tty_write_room(struct tty_struct *tty) +{ + struct bcm_vk *vk = dev_get_drvdata(tty->dev); + + return vk->tty[tty->index].to_size - 1; +} + +static const struct tty_operations serial_ops = { + .open = bcm_vk_tty_open, + .close = bcm_vk_tty_close, + .write = bcm_vk_tty_write, + .write_room = bcm_vk_tty_write_room, +}; + +int bcm_vk_tty_init(struct bcm_vk *vk, char *name) +{ + int i; + int err; + struct tty_driver *tty_drv; + struct device *dev = &vk->pdev->dev; + + tty_drv = tty_alloc_driver + (BCM_VK_NUM_TTY, + TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV); + if (IS_ERR(tty_drv)) + return PTR_ERR(tty_drv); + + /* Save struct tty_driver for uninstalling the device */ + vk->tty_drv = tty_drv; + + /* initialize the tty driver */ + tty_drv->driver_name = KBUILD_MODNAME; + tty_drv->name = kstrdup(name, GFP_KERNEL); + if (!tty_drv->name) { + err = -ENOMEM; + goto err_tty_driver_kref_put; + } + tty_drv->type = TTY_DRIVER_TYPE_SERIAL; + tty_drv->subtype = SERIAL_TYPE_NORMAL; + tty_drv->init_termios = tty_std_termios; + tty_set_operations(tty_drv, &serial_ops); + + /* register the tty driver */ + err = tty_register_driver(tty_drv); + if (err) { + dev_err(dev, "tty_register_driver failed\n"); + goto err_kfree_tty_name; + } + + for (i = 0; i < BCM_VK_NUM_TTY; i++) { + struct device *tty_dev; + + tty_port_init(&vk->tty[i].port); + tty_dev = tty_port_register_device_attr(&vk->tty[i].port, + tty_drv, i, dev, vk, + NULL); + if (IS_ERR(tty_dev)) { + err = PTR_ERR(tty_dev); + goto unwind; + } + vk->tty[i].is_opened = false; + } + + INIT_WORK(&vk->tty_wq_work, bcm_vk_tty_wq_handler); + vk->tty_wq_thread = create_singlethread_workqueue("tty"); + if (!vk->tty_wq_thread) { + dev_err(dev, "Fail to create tty workqueue thread\n"); + err = -ENOMEM; + goto unwind; + } + return 0; + +unwind: + while (--i >= 0) + tty_port_unregister_device(&vk->tty[i].port, tty_drv, i); + tty_unregister_driver(tty_drv); + +err_kfree_tty_name: + kfree(tty_drv->name); + tty_drv->name = NULL; + +err_tty_driver_kref_put: + tty_driver_kref_put(tty_drv); + + return err; +} + +void bcm_vk_tty_exit(struct bcm_vk *vk) +{ + int i; + + del_timer_sync(&vk->serial_timer); + for (i = 0; i < BCM_VK_NUM_TTY; ++i) { + tty_port_unregister_device(&vk->tty[i].port, + vk->tty_drv, + i); + tty_port_destroy(&vk->tty[i].port); + } + tty_unregister_driver(vk->tty_drv); + + kfree(vk->tty_drv->name); + vk->tty_drv->name = NULL; + + tty_driver_kref_put(vk->tty_drv); +} + +void bcm_vk_tty_terminate_tty_user(struct bcm_vk *vk) +{ + struct bcm_vk_tty *vktty; + int i; + + for (i = 0; i < BCM_VK_NUM_TTY; ++i) { + vktty = &vk->tty[i]; + if (vktty->pid) + kill_pid(find_vpid(vktty->pid), SIGKILL, 1); + } +} + +void bcm_vk_tty_wq_exit(struct bcm_vk *vk) +{ + cancel_work_sync(&vk->tty_wq_work); + destroy_workqueue(vk->tty_wq_thread); +} -- cgit v1.2.3