From a5f7a5bb3b7f28ba7e4fa246775b29a0e5537255 Mon Sep 17 00:00:00 2001 From: Jinke Han Date: Tue, 8 Sep 2026 15:37:42 +0800 Subject: x86/kprobes: Fix crash when probing CS CALL instructions When using eBPF to probe CS CALL instructions within a function, a crash can be triggered. The eBPF tool probes offset 257 of the __hrtimer_run_queues() function: <__hrtimer_run_queues+249>: nopl 0x0(%rax,%rax,1) <__hrtimer_run_queues+254>: mov %r14,%rdi <__hrtimer_run_queues+257>: cs call <__x86_indirect_thunk_r12> <__hrtimer_run_queues+263>: mov %eax,%r12d <__hrtimer_run_queues+266>: xchg %ax,%ax <__hrtimer_run_queues+268>: mov %r13,%rdi Which triggers this crash: BUG: unable to handle page fault for address: 00000000000f41c9 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI CPU: 1 PID: 0 Comm: swapper/1 Kdump: loaded Tainted: P RIP: 0010:__hrtimer_run_queues+0x106/0x230 Note that __hrtimer_run_queues+0x106 is __hrtimer_run_queues+262, which is at the 6th byte of the above CS CALL instruction. Since the CS CALL instruction occupies 6 bytes, the exception occurred in the middle of that call instruction. The root cause is that when using eBPF tools to probe in the middle of a function, a kprobe with INT3 is used as the underlying implementation. During single-step emulation of the original CALL instruction, int3_emulate_call() assumes that the probed CALL instruction is 5 bytes long. However, the actual CS-prefixed CALL instruction occupies 6 bytes, so it constructs an incorrect exception return address. When the CPU returns from the kprobe handler, the next instruction to be executed is at the address of the last byte of that CS CALL instruction. Coincidentally, starting from that address, the CPU fetches and decodes a completely different instruction, which ultimately triggers a kernel crash. Fix the issue by using the actual instruction length obtained from the instruction decoder when constructing the exception return address, rather than relying on the hardcoded CALL_INSN_SIZE macro. [ mingo: Refined the changelog ] Fixes: 6256e668b7af ("x86/kprobes: Use int3 instead of debug trap for single-step") Suggested-by: Masami Hiramatsu (Google) Signed-off-by: Jinke Han Signed-off-by: Ingo Molnar Reviewed-by: Masami Hiramatsu (Google) Acked-by: Yafang Shao Acked-by: Borislav Petkov Cc: Peter Zijlstra Link: https://patch.msgid.link/20260908073742.GA10517@didi-ThinkCentre-M920t-N000 --- drivers/tty/serial/max3100.c | 840 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 840 insertions(+) create mode 100644 drivers/tty/serial/max3100.c (limited to 'drivers/tty/serial/max3100.c') diff --git a/drivers/tty/serial/max3100.c b/drivers/tty/serial/max3100.c new file mode 100644 index 000000000..a5a5cd68f --- /dev/null +++ b/drivers/tty/serial/max3100.c @@ -0,0 +1,840 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2008 Christian Pellegrin + * + * Notes: the MAX3100 doesn't provide an interrupt on CTS so we have + * to use polling for flow control. TX empty IRQ is unusable, since + * writing conf clears FIFO buffer and we cannot have this interrupt + * always asking us for attention. + * + * The initial minor number is 209 in the low-density serial port: + * mknod /dev/ttyMAX0 c 204 209 + */ + +#define MAX3100_MAJOR 204 +#define MAX3100_MINOR 209 +/* 4 MAX3100s should be enough for everyone */ +#define MAX_MAX3100 4 + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define MAX3100_C (1<<14) +#define MAX3100_D (0<<14) +#define MAX3100_W (1<<15) +#define MAX3100_RX (0<<15) + +#define MAX3100_WC (MAX3100_W | MAX3100_C) +#define MAX3100_RC (MAX3100_RX | MAX3100_C) +#define MAX3100_WD (MAX3100_W | MAX3100_D) +#define MAX3100_RD (MAX3100_RX | MAX3100_D) +#define MAX3100_CMD (3 << 14) + +#define MAX3100_T (1<<14) +#define MAX3100_R (1<<15) + +#define MAX3100_FEN (1<<13) +#define MAX3100_SHDN (1<<12) +#define MAX3100_TM (1<<11) +#define MAX3100_RM (1<<10) +#define MAX3100_PM (1<<9) +#define MAX3100_RAM (1<<8) +#define MAX3100_IR (1<<7) +#define MAX3100_ST (1<<6) +#define MAX3100_PE (1<<5) +#define MAX3100_L (1<<4) +#define MAX3100_BAUD (0xf) + +#define MAX3100_TE (1<<10) +#define MAX3100_RAFE (1<<10) +#define MAX3100_RTS (1<<9) +#define MAX3100_CTS (1<<9) +#define MAX3100_PT (1<<8) +#define MAX3100_DATA (0xff) + +#define MAX3100_RT (MAX3100_R | MAX3100_T) +#define MAX3100_RTC (MAX3100_RT | MAX3100_CTS | MAX3100_RAFE) + +/* the following simulate a status reg for ignore_status_mask */ +#define MAX3100_STATUS_PE 1 +#define MAX3100_STATUS_FE 2 +#define MAX3100_STATUS_OE 4 + +struct max3100_port { + struct uart_port port; + struct spi_device *spi; + + int cts; /* last CTS received for flow ctrl */ + int tx_empty; /* last TX empty bit */ + + spinlock_t conf_lock; /* shared data */ + int conf_commit; /* need to make changes */ + int conf; /* configuration for the MAX31000 + * (bits 0-7, bits 8-11 are irqs) */ + int rts_commit; /* need to change rts */ + int rts; /* rts status */ + int baud; /* current baud rate */ + + int parity; /* keeps track if we should send parity */ +#define MAX3100_PARITY_ON 1 +#define MAX3100_PARITY_ODD 2 +#define MAX3100_7BIT 4 + int rx_enabled; /* if we should rx chars */ + + int minor; /* minor number */ + int loopback_commit; /* need to change loopback */ + int loopback; /* 1 if we are in loopback mode */ + + /* for handling irqs: need workqueue since we do spi_sync */ + struct workqueue_struct *workqueue; + struct work_struct work; + /* set to 1 to make the workhandler exit as soon as possible */ + int force_end_work; + /* need to know we are suspending to avoid deadlock on workqueue */ + int suspending; + + struct timer_list timer; +}; + +static inline struct max3100_port *to_max3100_port(struct uart_port *port) +{ + return container_of(port, struct max3100_port, port); +} + +static struct max3100_port *max3100s[MAX_MAX3100]; /* the chips */ +static DEFINE_MUTEX(max3100s_lock); /* race on probe */ + +static int max3100_do_parity(struct max3100_port *s, u16 c) +{ + int parity; + + if (s->parity & MAX3100_PARITY_ODD) + parity = 1; + else + parity = 0; + + if (s->parity & MAX3100_7BIT) + c &= 0x7f; + else + c &= 0xff; + + parity = parity ^ parity8(c); + return parity; +} + +static int max3100_check_parity(struct max3100_port *s, u16 c) +{ + return max3100_do_parity(s, c) == ((c >> 8) & 1); +} + +static void max3100_calc_parity(struct max3100_port *s, u16 *c) +{ + if (s->parity & MAX3100_7BIT) + *c &= 0x7f; + else + *c &= 0xff; + + if (s->parity & MAX3100_PARITY_ON) + *c |= max3100_do_parity(s, *c) << 8; +} + +static int max3100_sr(struct max3100_port *s, u16 tx, u16 *rx) +{ + struct spi_message message; + __be16 etx, erx; + int status; + struct spi_transfer tran = { + .tx_buf = &etx, + .rx_buf = &erx, + .len = 2, + }; + + etx = cpu_to_be16(tx); + spi_message_init(&message); + spi_message_add_tail(&tran, &message); + status = spi_sync(s->spi, &message); + if (status) { + dev_warn(&s->spi->dev, "error while calling spi_sync\n"); + return -EIO; + } + *rx = be16_to_cpu(erx); + s->tx_empty = (*rx & MAX3100_T) > 0; + dev_dbg(&s->spi->dev, "%04x - %04x\n", tx, *rx); + return 0; +} + +static int max3100_handlerx_unlocked(struct max3100_port *s, u16 rx) +{ + unsigned int status = 0; + int ret = 0, cts; + u8 ch, flg; + + if (rx & MAX3100_R && s->rx_enabled) { + dev_dbg(&s->spi->dev, "%s\n", __func__); + ch = rx & (s->parity & MAX3100_7BIT ? 0x7f : 0xff); + if (rx & MAX3100_RAFE) { + s->port.icount.frame++; + flg = TTY_FRAME; + status |= MAX3100_STATUS_FE; + } else { + if (s->parity & MAX3100_PARITY_ON) { + if (max3100_check_parity(s, rx)) { + s->port.icount.rx++; + flg = TTY_NORMAL; + } else { + s->port.icount.parity++; + flg = TTY_PARITY; + status |= MAX3100_STATUS_PE; + } + } else { + s->port.icount.rx++; + flg = TTY_NORMAL; + } + } + uart_insert_char(&s->port, status, MAX3100_STATUS_OE, ch, flg); + ret = 1; + } + + cts = (rx & MAX3100_CTS) > 0; + if (s->cts != cts) { + s->cts = cts; + uart_handle_cts_change(&s->port, cts); + } + + return ret; +} + +static int max3100_handlerx(struct max3100_port *s, u16 rx) +{ + unsigned long flags; + int ret; + + uart_port_lock_irqsave(&s->port, &flags); + ret = max3100_handlerx_unlocked(s, rx); + uart_port_unlock_irqrestore(&s->port, flags); + return ret; +} + +static void max3100_work(struct work_struct *w) +{ + struct max3100_port *s = container_of(w, struct max3100_port, work); + struct tty_port *tport = &s->port.state->port; + unsigned char ch; + int conf, cconf, cloopback, crts; + int rxchars; + u16 tx, rx; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + rxchars = 0; + do { + spin_lock(&s->conf_lock); + conf = s->conf; + cconf = s->conf_commit; + s->conf_commit = 0; + cloopback = s->loopback_commit; + s->loopback_commit = 0; + crts = s->rts_commit; + s->rts_commit = 0; + spin_unlock(&s->conf_lock); + if (cconf) + max3100_sr(s, MAX3100_WC | conf, &rx); + if (cloopback) + max3100_sr(s, 0x4001, &rx); + if (crts) { + max3100_sr(s, MAX3100_WD | MAX3100_TE | + (s->rts ? MAX3100_RTS : 0), &rx); + rxchars += max3100_handlerx(s, rx); + } + + max3100_sr(s, MAX3100_RD, &rx); + rxchars += max3100_handlerx(s, rx); + + if (rx & MAX3100_T) { + tx = 0xffff; + if (s->port.x_char) { + tx = s->port.x_char; + s->port.icount.tx++; + s->port.x_char = 0; + } else if (!uart_tx_stopped(&s->port) && + uart_fifo_get(&s->port, &ch)) { + tx = ch; + } + if (tx != 0xffff) { + max3100_calc_parity(s, &tx); + tx |= MAX3100_WD | (s->rts ? MAX3100_RTS : 0); + max3100_sr(s, tx, &rx); + rxchars += max3100_handlerx(s, rx); + } + } + + if (rxchars > 16) { + tty_flip_buffer_push(&s->port.state->port); + rxchars = 0; + } + if (kfifo_len(&tport->xmit_fifo) < WAKEUP_CHARS) + uart_write_wakeup(&s->port); + + } while (!s->force_end_work && + !freezing(current) && + ((rx & MAX3100_R) || + (!kfifo_is_empty(&tport->xmit_fifo) && + !uart_tx_stopped(&s->port)))); + + if (rxchars > 0) + tty_flip_buffer_push(&s->port.state->port); +} + +static void max3100_dowork(struct max3100_port *s) +{ + if (!s->force_end_work && !freezing(current) && !s->suspending) + queue_work(s->workqueue, &s->work); +} + +static void max3100_timeout(struct timer_list *t) +{ + struct max3100_port *s = timer_container_of(s, t, timer); + + max3100_dowork(s); + mod_timer(&s->timer, jiffies + uart_poll_timeout(&s->port)); +} + +static irqreturn_t max3100_irq(int irqno, void *dev_id) +{ + struct max3100_port *s = dev_id; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + max3100_dowork(s); + return IRQ_HANDLED; +} + +static void max3100_enable_ms(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + mod_timer(&s->timer, jiffies); + dev_dbg(&s->spi->dev, "%s\n", __func__); +} + +static void max3100_start_tx(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + max3100_dowork(s); +} + +static void max3100_stop_rx(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + s->rx_enabled = 0; + spin_lock(&s->conf_lock); + s->conf &= ~MAX3100_RM; + s->conf_commit = 1; + spin_unlock(&s->conf_lock); + max3100_dowork(s); +} + +static unsigned int max3100_tx_empty(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + /* may not be truly up-to-date */ + max3100_dowork(s); + return s->tx_empty; +} + +static unsigned int max3100_get_mctrl(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + /* may not be truly up-to-date */ + max3100_dowork(s); + /* always assert DCD and DSR since these lines are not wired */ + return (s->cts ? TIOCM_CTS : 0) | TIOCM_DSR | TIOCM_CAR; +} + +static void max3100_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct max3100_port *s = to_max3100_port(port); + int loopback, rts; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + loopback = (mctrl & TIOCM_LOOP) > 0; + rts = (mctrl & TIOCM_RTS) > 0; + + spin_lock(&s->conf_lock); + if (s->loopback != loopback) { + s->loopback = loopback; + s->loopback_commit = 1; + } + if (s->rts != rts) { + s->rts = rts; + s->rts_commit = 1; + } + if (s->loopback_commit || s->rts_commit) + max3100_dowork(s); + spin_unlock(&s->conf_lock); +} + +static void +max3100_set_termios(struct uart_port *port, struct ktermios *termios, + const struct ktermios *old) +{ + struct max3100_port *s = to_max3100_port(port); + unsigned int baud = port->uartclk / 16; + unsigned int baud230400 = (baud == 230400) ? 1 : 0; + unsigned cflag; + u32 param_new, param_mask, parity = 0; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + cflag = termios->c_cflag; + param_mask = 0; + + baud = tty_termios_baud_rate(termios); + param_new = s->conf & MAX3100_BAUD; + switch (baud) { + case 300: + if (baud230400) + baud = s->baud; + else + param_new = 15; + break; + case 600: + param_new = 14 + baud230400; + break; + case 1200: + param_new = 13 + baud230400; + break; + case 2400: + param_new = 12 + baud230400; + break; + case 4800: + param_new = 11 + baud230400; + break; + case 9600: + param_new = 10 + baud230400; + break; + case 19200: + param_new = 9 + baud230400; + break; + case 38400: + param_new = 8 + baud230400; + break; + case 57600: + param_new = 1 + baud230400; + break; + case 115200: + param_new = 0 + baud230400; + break; + case 230400: + if (baud230400) + param_new = 0; + else + baud = s->baud; + break; + default: + baud = s->baud; + } + tty_termios_encode_baud_rate(termios, baud, baud); + s->baud = baud; + param_mask |= MAX3100_BAUD; + + if ((cflag & CSIZE) == CS8) { + param_new &= ~MAX3100_L; + parity &= ~MAX3100_7BIT; + } else { + param_new |= MAX3100_L; + parity |= MAX3100_7BIT; + cflag = (cflag & ~CSIZE) | CS7; + } + param_mask |= MAX3100_L; + + if (cflag & CSTOPB) + param_new |= MAX3100_ST; + else + param_new &= ~MAX3100_ST; + param_mask |= MAX3100_ST; + + if (cflag & PARENB) { + param_new |= MAX3100_PE; + parity |= MAX3100_PARITY_ON; + } else { + param_new &= ~MAX3100_PE; + parity &= ~MAX3100_PARITY_ON; + } + param_mask |= MAX3100_PE; + + if (cflag & PARODD) + parity |= MAX3100_PARITY_ODD; + else + parity &= ~MAX3100_PARITY_ODD; + + /* mask termios capabilities we don't support */ + cflag &= ~CMSPAR; + termios->c_cflag = cflag; + + s->port.ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + s->port.ignore_status_mask |= + MAX3100_STATUS_PE | MAX3100_STATUS_FE | + MAX3100_STATUS_OE; + + timer_delete_sync(&s->timer); + uart_update_timeout(port, termios->c_cflag, baud); + + spin_lock(&s->conf_lock); + s->conf = (s->conf & ~param_mask) | (param_new & param_mask); + s->conf_commit = 1; + s->parity = parity; + spin_unlock(&s->conf_lock); + max3100_dowork(s); + + if (UART_ENABLE_MS(&s->port, termios->c_cflag)) + max3100_enable_ms(&s->port); +} + +static void max3100_shutdown(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + u16 rx; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + if (s->suspending) + return; + + s->force_end_work = 1; + + timer_delete_sync(&s->timer); + + if (s->workqueue) { + destroy_workqueue(s->workqueue); + s->workqueue = NULL; + } + if (port->irq) + free_irq(port->irq, s); + + /* set shutdown mode to save power */ + max3100_sr(s, MAX3100_WC | MAX3100_SHDN, &rx); +} + +static int max3100_startup(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + char b[12]; + int ret; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + s->conf = MAX3100_RM; + s->baud = port->uartclk / 16; + s->rx_enabled = 1; + + if (s->suspending) + return 0; + + s->force_end_work = 0; + s->parity = 0; + s->rts = 0; + + sprintf(b, "max3100-%d", s->minor); + s->workqueue = create_freezable_workqueue(b); + if (!s->workqueue) { + dev_warn(&s->spi->dev, "cannot create workqueue\n"); + return -EBUSY; + } + INIT_WORK(&s->work, max3100_work); + + ret = request_irq(port->irq, max3100_irq, IRQF_TRIGGER_FALLING, "max3100", s); + if (ret < 0) { + dev_warn(&s->spi->dev, "cannot allocate irq %d\n", port->irq); + port->irq = 0; + destroy_workqueue(s->workqueue); + s->workqueue = NULL; + return -EBUSY; + } + + s->conf_commit = 1; + max3100_dowork(s); + /* wait for clock to settle */ + msleep(50); + + max3100_enable_ms(&s->port); + + return 0; +} + +static const char *max3100_type(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + return s->port.type == PORT_MAX3100 ? "MAX3100" : NULL; +} + +static void max3100_release_port(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); +} + +static void max3100_config_port(struct uart_port *port, int flags) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + if (flags & UART_CONFIG_TYPE) + s->port.type = PORT_MAX3100; +} + +static int max3100_verify_port(struct uart_port *port, + struct serial_struct *ser) +{ + struct max3100_port *s = to_max3100_port(port); + int ret = -EINVAL; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + if (ser->type == PORT_UNKNOWN || ser->type == PORT_MAX3100) + ret = 0; + return ret; +} + +static void max3100_stop_tx(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); +} + +static int max3100_request_port(struct uart_port *port) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + return 0; +} + +static void max3100_break_ctl(struct uart_port *port, int break_state) +{ + struct max3100_port *s = to_max3100_port(port); + + dev_dbg(&s->spi->dev, "%s\n", __func__); +} + +static const struct uart_ops max3100_ops = { + .tx_empty = max3100_tx_empty, + .set_mctrl = max3100_set_mctrl, + .get_mctrl = max3100_get_mctrl, + .stop_tx = max3100_stop_tx, + .start_tx = max3100_start_tx, + .stop_rx = max3100_stop_rx, + .enable_ms = max3100_enable_ms, + .break_ctl = max3100_break_ctl, + .startup = max3100_startup, + .shutdown = max3100_shutdown, + .set_termios = max3100_set_termios, + .type = max3100_type, + .release_port = max3100_release_port, + .request_port = max3100_request_port, + .config_port = max3100_config_port, + .verify_port = max3100_verify_port, +}; + +static struct uart_driver max3100_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "ttyMAX", + .dev_name = "ttyMAX", + .major = MAX3100_MAJOR, + .minor = MAX3100_MINOR, + .nr = MAX_MAX3100, +}; +static int uart_driver_registered; + +static int max3100_probe(struct spi_device *spi) +{ + struct device *dev = &spi->dev; + int i, retval; + u16 rx; + + mutex_lock(&max3100s_lock); + + if (!uart_driver_registered) { + retval = uart_register_driver(&max3100_uart_driver); + if (retval) { + mutex_unlock(&max3100s_lock); + return dev_err_probe(dev, retval, "Couldn't register max3100 uart driver\n"); + } + + uart_driver_registered = 1; + } + + for (i = 0; i < MAX_MAX3100; i++) + if (!max3100s[i]) + break; + if (i == MAX_MAX3100) { + mutex_unlock(&max3100s_lock); + return dev_err_probe(dev, -ENOSPC, "too many MAX3100 chips\n"); + } + + max3100s[i] = kzalloc_obj(struct max3100_port); + if (!max3100s[i]) { + mutex_unlock(&max3100s_lock); + return -ENOMEM; + } + max3100s[i]->spi = spi; + spin_lock_init(&max3100s[i]->conf_lock); + spi_set_drvdata(spi, max3100s[i]); + max3100s[i]->minor = i; + timer_setup(&max3100s[i]->timer, max3100_timeout, 0); + + dev_dbg(&spi->dev, "%s: adding port %d\n", __func__, i); + max3100s[i]->port.irq = spi->irq; + max3100s[i]->port.fifosize = 16; + max3100s[i]->port.ops = &max3100_ops; + max3100s[i]->port.flags = UPF_SKIP_TEST | UPF_BOOT_AUTOCONF; + max3100s[i]->port.line = i; + max3100s[i]->port.iotype = UPIO_BUS; + max3100s[i]->port.type = PORT_MAX3100; + max3100s[i]->port.dev = &spi->dev; + + /* Read clock frequency from a property, uart_add_one_port() will fail if it's not set */ + device_property_read_u32(dev, "clock-frequency", &max3100s[i]->port.uartclk); + + retval = uart_add_one_port(&max3100_uart_driver, &max3100s[i]->port); + if (retval < 0) + dev_err_probe(dev, retval, "uart_add_one_port failed for line %d\n", i); + + /* set shutdown mode to save power. Will be woken-up on open */ + max3100_sr(max3100s[i], MAX3100_WC | MAX3100_SHDN, &rx); + mutex_unlock(&max3100s_lock); + return 0; +} + +static void max3100_remove(struct spi_device *spi) +{ + struct max3100_port *s = spi_get_drvdata(spi); + int i; + + mutex_lock(&max3100s_lock); + + /* find out the index for the chip we are removing */ + for (i = 0; i < MAX_MAX3100; i++) + if (max3100s[i] == s) { + dev_dbg(&spi->dev, "%s: removing port %d\n", __func__, i); + uart_remove_one_port(&max3100_uart_driver, &max3100s[i]->port); + kfree(max3100s[i]); + max3100s[i] = NULL; + break; + } + + WARN_ON(i == MAX_MAX3100); + + /* check if this is the last chip we have */ + for (i = 0; i < MAX_MAX3100; i++) + if (max3100s[i]) { + mutex_unlock(&max3100s_lock); + return; + } + pr_debug("removing max3100 driver\n"); + uart_unregister_driver(&max3100_uart_driver); + uart_driver_registered = 0; + + mutex_unlock(&max3100s_lock); +} + +static int max3100_suspend(struct device *dev) +{ + struct max3100_port *s = dev_get_drvdata(dev); + u16 rx; + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + disable_irq(s->port.irq); + + s->suspending = 1; + uart_suspend_port(&max3100_uart_driver, &s->port); + + /* no HW suspend, so do SW one */ + max3100_sr(s, MAX3100_WC | MAX3100_SHDN, &rx); + return 0; +} + +static int max3100_resume(struct device *dev) +{ + struct max3100_port *s = dev_get_drvdata(dev); + + dev_dbg(&s->spi->dev, "%s\n", __func__); + + uart_resume_port(&max3100_uart_driver, &s->port); + s->suspending = 0; + + enable_irq(s->port.irq); + + s->conf_commit = 1; + if (s->workqueue) + max3100_dowork(s); + + return 0; +} + +static DEFINE_SIMPLE_DEV_PM_OPS(max3100_pm_ops, max3100_suspend, max3100_resume); + +static const struct spi_device_id max3100_spi_id[] = { + { "max3100" }, + { } +}; +MODULE_DEVICE_TABLE(spi, max3100_spi_id); + +static const struct of_device_id max3100_of_match[] = { + { .compatible = "maxim,max3100" }, + { } +}; +MODULE_DEVICE_TABLE(of, max3100_of_match); + +static struct spi_driver max3100_driver = { + .driver = { + .name = "max3100", + .of_match_table = max3100_of_match, + .pm = pm_sleep_ptr(&max3100_pm_ops), + }, + .probe = max3100_probe, + .remove = max3100_remove, + .id_table = max3100_spi_id, +}; + +module_spi_driver(max3100_driver); + +MODULE_DESCRIPTION("MAX3100 driver"); +MODULE_AUTHOR("Christian Pellegrin "); +MODULE_LICENSE("GPL"); -- cgit v1.3.1