int ptrace_attach(struct task_struct *task)
{
int retval;
unsigned long flags;
audit_ptrace(task);
retval = -EPERM;
if (same_thread_group(task, current))
goto out;
/* Protect exec's credential calculations against our interference;
* SUID, SGID and LSM creds get determined differently under ptrace.
*/
retval = mutex_lock_interruptible(&task->cred_exec_mutex);
if (retval < 0)
goto out;
retval = -EPERM;
repeat:
/*
* Nasty, nasty.
*
* We want to hold both the task-lock and the
* tasklist_lock for writing at the same time.
* But that's against the rules (tasklist_lock
* is taken for reading by interrupts on other
* cpu's that may have task_lock).
*/
task_lock(task);
if (!write_trylock_irqsave(&tasklist_lock, flags)) {
task_unlock(task);
do {
cpu_relax();
} while (!write_can_lock(&tasklist_lock));
goto repeat;
}
if (!task->mm)
goto bad;
/* the same process cannot be attached many times */
if (task->ptrace & PT_PTRACED)
goto bad;
retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH);
if (retval)
goto bad;
/* Go */
task->ptrace |= PT_PTRACED;
if (capable(CAP_SYS_PTRACE))
task->ptrace |= PT_PTRACE_CAP;
__ptrace_link(task, current);
send_sig_info(SIGSTOP, SEND_SIG_FORCED, task);
bad:
write_unlock_irqrestore(&tasklist_lock, flags);
task_unlock(task);
mutex_unlock(&task->cred_exec_mutex);
out:
return retval;
}
/**
* dwc3_core_init - Low-level initialization of DWC3 Core
* @dwc: Pointer to our controller context structure
*
* Returns 0 on success otherwise negative errno.
*/
static int dwc3_core_init(struct dwc3 *dwc)
{
unsigned long timeout;
u32 reg;
int ret;
reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
/* This should read as U3 followed by revision number */
if ((reg & DWC3_GSNPSID_MASK) != 0x55330000) {
dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
ret = -ENODEV;
goto err0;
}
dwc->revision = reg;
/* issue device SoftReset too */
timeout = jiffies + msecs_to_jiffies(500);
dwc3_writel(dwc->regs, DWC3_DCTL, DWC3_DCTL_CSFTRST);
do {
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
if (!(reg & DWC3_DCTL_CSFTRST))
break;
if (time_after(jiffies, timeout)) {
dev_err(dwc->dev, "Reset Timed Out\n");
ret = -ETIMEDOUT;
goto err0;
}
cpu_relax();
} while (true);
dwc3_core_soft_reset(dwc);
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
reg &= ~DWC3_GCTL_DISSCRAMBLE;
switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1)) {
case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
reg &= ~DWC3_GCTL_DSBLCLKGTNG;
break;
default:
dev_dbg(dwc->dev, "No power optimization available\n");
}
/*
* WORKAROUND: DWC3 revisions <1.90a have a bug
* where the device can fail to connect at SuperSpeed
* and falls back to high-speed mode which causes
* the device to enter a Connect/Disconnect loop
*/
if (dwc->revision < DWC3_REVISION_190A)
reg |= DWC3_GCTL_U2RSTECN;
dwc3_writel(dwc->regs, DWC3_GCTL, reg);
ret = dwc3_event_buffers_setup(dwc);
if (ret) {
dev_err(dwc->dev, "failed to setup event buffers\n");
goto err0;
}
return 0;
err0:
return ret;
}
/*
* Low level master read/write transaction.
*/
static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
struct i2c_msg *msg, int stop)
{
struct omap_i2c_dev *omap = i2c_get_adapdata(adap);
unsigned long timeout;
u16 w;
dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
msg->addr, msg->len, msg->flags, stop);
if (msg->len == 0)
return -EINVAL;
omap->receiver = !!(msg->flags & I2C_M_RD);
omap_i2c_resize_fifo(omap, msg->len, omap->receiver);
omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr);
/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
omap->buf = msg->buf;
omap->buf_len = msg->len;
/* make sure writes to omap->buf_len are ordered */
barrier();
omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len);
/* Clear the FIFO Buffers */
w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG);
w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w);
reinit_completion(&omap->cmd_complete);
omap->cmd_err = 0;
w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
/* High speed configuration */
if (omap->speed > 400)
w |= OMAP_I2C_CON_OPMODE_HS;
if (msg->flags & I2C_M_STOP)
stop = 1;
if (msg->flags & I2C_M_TEN)
w |= OMAP_I2C_CON_XA;
if (!(msg->flags & I2C_M_RD))
w |= OMAP_I2C_CON_TRX;
if (!omap->b_hw && stop)
w |= OMAP_I2C_CON_STP;
/*
* NOTE: STAT_BB bit could became 1 here if another master occupy
* the bus. IP successfully complete transfer when the bus will be
* free again (BB reset to 0).
*/
omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
/*
* Don't write stt and stp together on some hardware.
*/
if (omap->b_hw && stop) {
unsigned long delay = jiffies + OMAP_I2C_TIMEOUT;
u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
while (con & OMAP_I2C_CON_STT) {
con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG);
/* Let the user know if i2c is in a bad state */
if (time_after(jiffies, delay)) {
dev_err(omap->dev, "controller timed out "
"waiting for start condition to finish\n");
return -ETIMEDOUT;
}
cpu_relax();
}
w |= OMAP_I2C_CON_STP;
w &= ~OMAP_I2C_CON_STT;
omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w);
}
/*
* REVISIT: We should abort the transfer on signals, but the bus goes
* into arbitration and we're currently unable to recover from it.
*/
timeout = wait_for_completion_timeout(&omap->cmd_complete,
OMAP_I2C_TIMEOUT);
if (timeout == 0) {
dev_err(omap->dev, "controller timed out\n");
omap_i2c_reset(omap);
__omap_i2c_init(omap);
return -ETIMEDOUT;
}
if (likely(!omap->cmd_err))
return 0;
/* We have an error */
//.........这里部分代码省略.........
开发者ID:020gzh,项目名称:linux,代码行数:101,代码来源:i2c-omap.c
示例5: vt8500_set_termios
static void vt8500_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
struct vt8500_port *vt8500_port =
container_of(port, struct vt8500_port, uart);
unsigned long flags;
unsigned int baud, lcr;
unsigned int loops = 1000;
spin_lock_irqsave(&port->lock, flags);
/* calculate and set baud rate */
baud = uart_get_baud_rate(port, termios, old, 900, 921600);
baud = vt8500_set_baud_rate(port, baud);
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
/* calculate parity */
lcr = vt8500_read(&vt8500_port->uart, VT8500_URLCR);
lcr &= ~((1 << 5) | (1 << 4));
if (termios->c_cflag & PARENB) {
lcr |= (1 << 4);
termios->c_cflag &= ~CMSPAR;
if (termios->c_cflag & PARODD)
lcr |= (1 << 5);
}
/* calculate bits per char */
lcr &= ~(1 << 2);
switch (termios->c_cflag & CSIZE) {
case CS7:
break;
case CS8:
default:
lcr |= (1 << 2);
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= CS8;
break;
}
/* calculate stop bits */
lcr &= ~(1 << 3);
if (termios->c_cflag & CSTOPB)
lcr |= (1 << 3);
/* set parity, bits per char, and stop bit */
vt8500_write(&vt8500_port->uart, lcr, VT8500_URLCR);
/* Configure status bits to ignore based on termio flags. */
port->read_status_mask = 0;
if (termios->c_iflag & IGNPAR)
port->read_status_mask = FER | PER;
uart_update_timeout(port, termios->c_cflag, baud);
/* Reset FIFOs */
vt8500_write(&vt8500_port->uart, 0x88c, VT8500_URFCR);
while ((vt8500_read(&vt8500_port->uart, VT8500_URFCR) & 0xc)
&& --loops)
cpu_relax();
/* Every possible FIFO-related interrupt */
vt8500_port->ier = RX_FIFO_INTS | TX_FIFO_INTS;
/*
* CTS flow control
*/
if (UART_ENABLE_MS(&vt8500_port->uart, termios->c_cflag))
vt8500_port->ier |= TCTS;
vt8500_write(&vt8500_port->uart, 0x881, VT8500_URFCR);
vt8500_write(&vt8500_port->uart, vt8500_port->ier, VT8500_URIER);
spin_unlock_irqrestore(&port->lock, flags);
}
int __cpu_up(unsigned int cpu, struct task_struct *tidle)
{
int rc, c;
/*
* Don't allow secondary threads to come online if inhibited
*/
if (threads_per_core > 1 && secondaries_inhibited() &&
cpu % threads_per_core != 0)
return -EBUSY;
if (smp_ops == NULL ||
(smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
return -EINVAL;
cpu_idle_thread_init(cpu, tidle);
/* Make sure callin-map entry is 0 (can be leftover a CPU
* hotplug
*/
cpu_callin_map[cpu] = 0;
/* The information for processor bringup must
* be written out to main store before we release
* the processor.
*/
smp_mb();
/* wake up cpus */
DBG("smp: kicking cpu %d\n", cpu);
rc = smp_ops->kick_cpu(cpu);
if (rc) {
pr_err("smp: failed starting cpu %d (rc %d)\n", cpu, rc);
return rc;
}
/*
* wait to see if the cpu made a callin (is actually up).
* use this value that I found through experimentation.
* -- Cort
*/
if (system_state < SYSTEM_RUNNING)
for (c = 50000; c && !cpu_callin_map[cpu]; c--)
udelay(100);
#ifdef CONFIG_HOTPLUG_CPU
else
/*
* CPUs can take much longer to come up in the
* hotplug case. Wait five seconds.
*/
for (c = 5000; c && !cpu_callin_map[cpu]; c--)
msleep(1);
#endif
if (!cpu_callin_map[cpu]) {
printk(KERN_ERR "Processor %u is stuck.\n", cpu);
return -ENOENT;
}
DBG("Processor %u found.\n", cpu);
if (smp_ops->give_timebase)
smp_ops->give_timebase();
/* Wait until cpu puts itself in the online map */
while (!cpu_online(cpu))
cpu_relax();
return 0;
}
开发者ID:AbelHu,项目名称:linux,代码行数:70,代码来源:smp.c
示例7: omap4_boot_secondary
static int omap4_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
static struct clockdomain *cpu1_clkdm;
static bool booted;
static struct powerdomain *cpu1_pwrdm;
void __iomem *base = omap_get_wakeupgen_base();
/*
* Set synchronisation state between this boot processor
* and the secondary one
*/
spin_lock(&boot_lock);
/*
* Update the AuxCoreBoot0 with boot state for secondary core.
* omap4_secondary_startup() routine will hold the secondary core till
* the AuxCoreBoot1 register is updated with cpu state
* A barrier is added to ensure that write buffer is drained
*/
if (omap_secure_apis_support())
omap_modify_auxcoreboot0(0x200, 0xfffffdff);
else
__raw_writel(0x20, base + OMAP_AUX_CORE_BOOT_0);
if (!cpu1_clkdm && !cpu1_pwrdm) {
cpu1_clkdm = clkdm_lookup("mpu1_clkdm");
cpu1_pwrdm = pwrdm_lookup("cpu1_pwrdm");
}
/*
* The SGI(Software Generated Interrupts) are not wakeup capable
* from low power states. This is known limitation on OMAP4 and
* needs to be worked around by using software forced clockdomain
* wake-up. To wakeup CPU1, CPU0 forces the CPU1 clockdomain to
* software force wakeup. The clockdomain is then put back to
* hardware supervised mode.
* More details can be found in OMAP4430 TRM - Version J
* Section :
* 4.3.4.2 Power States of CPU0 and CPU1
*/
if (booted && cpu1_pwrdm && cpu1_clkdm) {
/*
* GIC distributor control register has changed between
* CortexA9 r1pX and r2pX. The Control Register secure
* banked version is now composed of 2 bits:
* bit 0 == Secure Enable
* bit 1 == Non-Secure Enable
* The Non-Secure banked register has not changed
* Because the ROM Code is based on the r1pX GIC, the CPU1
* GIC restoration will cause a problem to CPU0 Non-Secure SW.
* The workaround must be:
* 1) Before doing the CPU1 wakeup, CPU0 must disable
* the GIC distributor
* 2) CPU1 must re-enable the GIC distributor on
* it's wakeup path.
*/
if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
local_irq_disable();
gic_dist_disable();
}
/*
* Ensure that CPU power state is set to ON to avoid CPU
* powerdomain transition on wfi
*/
clkdm_wakeup(cpu1_clkdm);
omap_set_pwrdm_state(cpu1_pwrdm, PWRDM_POWER_ON);
clkdm_allow_idle(cpu1_clkdm);
if (IS_PM44XX_ERRATUM(PM_OMAP4_ROM_SMP_BOOT_ERRATUM_GICD)) {
while (gic_dist_disabled()) {
udelay(1);
cpu_relax();
}
gic_timer_retrigger();
local_irq_enable();
}
} else {
dsb_sev();
booted = true;
}
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
/*
* Now the secondary core is starting up let it run its
* calibrations, then wait for it to finish
*/
spin_unlock(&boot_lock);
return 0;
}
开发者ID:1youhun1,项目名称:linux,代码行数:92,代码来源:omap-smp.c
示例8: dwc3_core_init
/**
* dwc3_core_init - Low-level initialization of DWC3 Core
* @dwc: Pointer to our controller context structure
*
* Returns 0 on success otherwise negative errno.
*/
static int dwc3_core_init(struct dwc3 *dwc)
{
unsigned long timeout;
u32 hwparams4 = dwc->hwparams.hwparams4;
u32 reg;
int ret;
reg = dwc3_readl(dwc->regs, DWC3_GSNPSID);
/* This should read as U3 followed by revision number */
if ((reg & DWC3_GSNPSID_MASK) != 0x55330000) {
dev_err(dwc->dev, "this is not a DesignWare USB3 DRD Core\n");
ret = -ENODEV;
goto err0;
}
dwc->revision = reg;
/* Handle USB2.0-only core configuration */
if (DWC3_GHWPARAMS3_SSPHY_IFC(dwc->hwparams.hwparams3) ==
DWC3_GHWPARAMS3_SSPHY_IFC_DIS) {
if (dwc->maximum_speed == USB_SPEED_SUPER)
dwc->maximum_speed = USB_SPEED_HIGH;
}
/* issue device SoftReset too */
timeout = jiffies + msecs_to_jiffies(500);
dwc3_writel(dwc->regs, DWC3_DCTL, DWC3_DCTL_CSFTRST);
do {
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
if (!(reg & DWC3_DCTL_CSFTRST))
break;
if (time_after(jiffies, timeout)) {
dev_err(dwc->dev, "Reset Timed Out\n");
ret = -ETIMEDOUT;
goto err0;
}
cpu_relax();
} while (true);
ret = dwc3_core_soft_reset(dwc);
if (ret)
goto err0;
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
reg &= ~DWC3_GCTL_SCALEDOWN_MASK;
reg &= ~DWC3_GCTL_DISSCRAMBLE;
switch (DWC3_GHWPARAMS1_EN_PWROPT(dwc->hwparams.hwparams1)) {
case DWC3_GHWPARAMS1_EN_PWROPT_CLK:
/**
* WORKAROUND: DWC3 revisions between 2.10a and 2.50a have an
* issue which would cause xHCI compliance tests to fail.
*
* Because of that we cannot enable clock gating on such
* configurations.
*
* Refers to:
*
* STAR#9000588375: Clock Gating, SOF Issues when ref_clk-Based
* SOF/ITP Mode Used
*/
if ((dwc->dr_mode == USB_DR_MODE_HOST ||
dwc->dr_mode == USB_DR_MODE_OTG) &&
(dwc->revision >= DWC3_REVISION_210A &&
dwc->revision <= DWC3_REVISION_250A))
reg |= DWC3_GCTL_DSBLCLKGTNG | DWC3_GCTL_SOFITPSYNC;
else
reg &= ~DWC3_GCTL_DSBLCLKGTNG;
break;
case DWC3_GHWPARAMS1_EN_PWROPT_HIB:
/* enable hibernation here */
dwc->nr_scratch = DWC3_GHWPARAMS4_HIBER_SCRATCHBUFS(hwparams4);
break;
default:
dev_dbg(dwc->dev, "No power optimization available\n");
}
/*
* WORKAROUND: DWC3 revisions <1.90a have a bug
* where the device can fail to connect at SuperSpeed
* and falls back to high-speed mode which causes
* the device to enter a Connect/Disconnect loop
*/
if (dwc->revision < DWC3_REVISION_190A)
reg |= DWC3_GCTL_U2RSTECN;
dwc3_core_num_eps(dwc);
dwc3_writel(dwc->regs, DWC3_GCTL, reg);
ret = dwc3_alloc_scratch_buffers(dwc);
if (ret)
goto err1;
//.........这里部分代码省略.........
int __cpuinit __cpu_up(unsigned int cpu)
{
int c;
secondary_ti = current_set[cpu];
if (!cpu_enable(cpu))
return 0;
if (smp_ops == NULL ||
(smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
return -EINVAL;
/* Make sure callin-map entry is 0 (can be leftover a CPU
* hotplug
*/
cpu_callin_map[cpu] = 0;
/* The information for processor bringup must
* be written out to main store before we release
* the processor.
*/
smp_mb();
/* wake up cpus */
DBG("smp: kicking cpu %d\n", cpu);
smp_ops->kick_cpu(cpu);
/*
* wait to see if the cpu made a callin (is actually up).
* use this value that I found through experimentation.
* -- Cort
*/
if (system_state < SYSTEM_RUNNING)
for (c = 50000; c && !cpu_callin_map[cpu]; c--)
udelay(100);
#ifdef CONFIG_HOTPLUG_CPU
else
/*
* CPUs can take much longer to come up in the
* hotplug case. Wait five seconds.
*/
for (c = 5000; c && !cpu_callin_map[cpu]; c--)
msleep(1);
#endif
if (!cpu_callin_map[cpu]) {
printk("Processor %u is stuck.\n", cpu);
return -ENOENT;
}
printk("Processor %u found.\n", cpu);
if (smp_ops->give_timebase)
smp_ops->give_timebase();
/* Wait until cpu puts itself in the online map */
while (!cpu_online(cpu))
cpu_relax();
return 0;
}
/* Requires cpu_add_remove_lock to be held */
static int _cpu_down(unsigned int cpu, int tasks_frozen)
{
int err, nr_calls = 0;
void *hcpu = (void *)(long)cpu;
unsigned long mod = tasks_frozen ? CPU_TASKS_FROZEN : 0;
struct take_cpu_down_param tcd_param = {
.mod = mod,
.hcpu = hcpu,
};
if (num_online_cpus() == 1)
return -EBUSY;
if (!cpu_online(cpu))
return -EINVAL;
cpu_hotplug_begin();
err = __cpu_notify(CPU_DOWN_PREPARE | mod, hcpu, -1, &nr_calls);
if (err) {
nr_calls--;
__cpu_notify(CPU_DOWN_FAILED | mod, hcpu, nr_calls, NULL);
pr_warn("%s: attempt to take down CPU %u failed\n",
__func__, cpu);
goto out_release;
}
/*
* By now we've cleared cpu_active_mask, wait for all preempt-disabled
* and RCU users of this state to go away such that all new such users
* will observe it.
*
* For CONFIG_PREEMPT we have preemptible RCU and its sync_rcu() might
* not imply sync_sched(), so wait for both.
*
* Do sync before park smpboot threads to take care the rcu boost case.
*/
if (IS_ENABLED(CONFIG_PREEMPT))
synchronize_rcu_mult(call_rcu, call_rcu_sched);
else
synchronize_rcu();
smpboot_park_threads(cpu);
/*
* Prevent irq alloc/free while the dying cpu reorganizes the
* interrupt affinities.
*/
irq_lock_sparse();
/*
* So now all preempt/rcu users must observe !cpu_active().
*/
err = stop_machine(take_cpu_down, &tcd_param, cpumask_of(cpu));
if (err) {
/* CPU didn't die: tell everyone. Can't complain. */
cpu_notify_nofail(CPU_DOWN_FAILED | mod, hcpu);
irq_unlock_sparse();
goto out_release;
}
BUG_ON(cpu_online(cpu));
/*
* The migration_call() CPU_DYING callback will have removed all
* runnable tasks from the cpu, there's only the idle task left now
* that the migration thread is done doing the stop_machine thing.
*
* Wait for the stop thread to go away.
*/
while (!per_cpu(cpu_dead_idle, cpu))
cpu_relax();
smp_mb(); /* Read from cpu_dead_idle before __cpu_die(). */
per_cpu(cpu_dead_idle, cpu) = false;
/* Interrupts are moved away from the dying cpu, reenable alloc/free */
irq_unlock_sparse();
hotplug_cpu__broadcast_tick_pull(cpu);
/* This actually kills the CPU. */
__cpu_die(cpu);
/* CPU is completely dead: tell everyone. Too late to complain. */
tick_cleanup_dead_cpu(cpu);
cpu_notify_nofail(CPU_DEAD | mod, hcpu);
check_for_tasks(cpu);
out_release:
cpu_hotplug_done();
if (!err)
cpu_notify_nofail(CPU_POST_DEAD | mod, hcpu);
return err;
}
开发者ID:andy-shev,项目名称:linux,代码行数:94,代码来源:cpu.c
示例13: cdns_uart_set_termios
/**
* cdns_uart_set_termios - termios operations, handling data length, parity,
* stop bits, flow control, baud rate
* @port: Handle to the uart port structure
* @termios: Handle to the input termios structure
* @old: Values of the previously saved termios structure
*/
static void cdns_uart_set_termios(struct uart_port *port,
struct ktermios *termios, struct ktermios *old)
{
unsigned int cval = 0;
unsigned int baud, minbaud, maxbaud;
unsigned long flags;
unsigned int ctrl_reg, mode_reg;
spin_lock_irqsave(&port->lock, flags);
/* Wait for the transmit FIFO to empty before making changes */
if (!(readl(port->membase + CDNS_UART_CR) &
CDNS_UART_CR_TX_DIS)) {
while (!(readl(port->membase + CDNS_UART_SR) &
CDNS_UART_SR_TXEMPTY)) {
cpu_relax();
}
}
/* Disable the TX and RX to set baud rate */
ctrl_reg = readl(port->membase + CDNS_UART_CR);
ctrl_reg |= CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS;
writel(ctrl_reg, port->membase + CDNS_UART_CR);
/*
* Min baud rate = 6bps and Max Baud Rate is 10Mbps for 100Mhz clk
* min and max baud should be calculated here based on port->uartclk.
* this way we get a valid baud and can safely call set_baud()
*/
minbaud = port->uartclk /
((CDNS_UART_BDIV_MAX + 1) * CDNS_UART_CD_MAX * 8);
maxbaud = port->uartclk / (CDNS_UART_BDIV_MIN + 1);
baud = uart_get_baud_rate(port, termios, old, minbaud, maxbaud);
baud = cdns_uart_set_baud_rate(port, baud);
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
/* Update the per-port timeout. */
uart_update_timeout(port, termios->c_cflag, baud);
/* Set TX/RX Reset */
ctrl_reg = readl(port->membase + CDNS_UART_CR);
ctrl_reg |= CDNS_UART_CR_TXRST | CDNS_UART_CR_RXRST;
writel(ctrl_reg, port->membase + CDNS_UART_CR);
/*
* Clear the RX disable and TX disable bits and then set the TX enable
* bit and RX enable bit to enable the transmitter and receiver.
*/
ctrl_reg = readl(port->membase + CDNS_UART_CR);
ctrl_reg &= ~(CDNS_UART_CR_TX_DIS | CDNS_UART_CR_RX_DIS);
ctrl_reg |= CDNS_UART_CR_TX_EN | CDNS_UART_CR_RX_EN;
writel(ctrl_reg, port->membase + CDNS_UART_CR);
writel(rx_timeout, port->membase + CDNS_UART_RXTOUT);
port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
port->ignore_status_mask = 0;
if (termios->c_iflag & INPCK)
port->read_status_mask |= CDNS_UART_IXR_PARITY |
CDNS_UART_IXR_FRAMING;
if (termios->c_iflag & IGNPAR)
port->ignore_status_mask |= CDNS_UART_IXR_PARITY |
CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
/* ignore all characters if CREAD is not set */
if ((termios->c_cflag & CREAD) == 0)
port->ignore_status_mask |= CDNS_UART_IXR_RXTRIG |
CDNS_UART_IXR_TOUT | CDNS_UART_IXR_PARITY |
CDNS_UART_IXR_FRAMING | CDNS_UART_IXR_OVERRUN;
mode_reg = readl(port->membase + CDNS_UART_MR);
/* Handling Data Size */
switch (termios->c_cflag & CSIZE) {
case CS6:
cval |= CDNS_UART_MR_CHARLEN_6_BIT;
break;
case CS7:
cval |= CDNS_UART_MR_CHARLEN_7_BIT;
break;
default:
case CS8:
cval |= CDNS_UART_MR_CHARLEN_8_BIT;
termios->c_cflag &= ~CSIZE;
termios->c_cflag |= CS8;
break;
}
/* Handling Parity and Stop Bits length */
//.........这里部分代码省略.........
/**ltl
功能:提交scatterlist urb请求,并等待执行结果
参数:
说明:此接口给usb_storage驱动使用<usb_stor_bulk_transfer_sglist>
*/
void usb_sg_wait (struct usb_sg_request *io)
{
int i, entries = io->entries;
/* queue the urbs. */
spin_lock_irq (&io->lock);
for (i = 0; i < entries && !io->status; i++) {
int retval;
io->urbs [i]->dev = io->dev;
retval = usb_submit_urb (io->urbs [i], SLAB_ATOMIC);
/* after we submit, let completions or cancelations fire;
* we handshake using io->status.
*/
spin_unlock_irq (&io->lock);
switch (retval) {
/* maybe we retrying will recover */
case -ENXIO: // hc didn't queue this one
case -EAGAIN:
case -ENOMEM:
io->urbs[i]->dev = NULL;
retval = 0;
i--;
yield ();
break;
/* no error? continue immediately.
*
* NOTE: to work better with UHCI (4K I/O buffer may
* need 3K of TDs) it may be good to limit how many
* URBs are queued at once; N milliseconds?
*/
case 0:
cpu_relax ();
break;
/* fail any uncompleted urbs */
default:
io->urbs [i]->dev = NULL;
io->urbs [i]->status = retval;
dev_dbg (&io->dev->dev, "%s, submit --> %d\n",
__FUNCTION__, retval);
usb_sg_cancel (io);
}
spin_lock_irq (&io->lock);
if (retval && (io->status == 0 || io->status == -ECONNRESET))
io->status = retval;
}
io->count -= entries - i;
if (io->count == 0)
complete (&io->complete);
spin_unlock_irq (&io->lock);
/* OK, yes, this could be packaged as non-blocking.
* So could the submit loop above ... but it's easier to
* solve neither problem than to solve both!
*/
wait_for_completion (&io->complete);
sg_clean (io);
}
请发表评论