OpenCloudOS-Kernel/drivers/hwtracing/coresight/coresight-etm4x.c

698 lines
19 KiB
C

/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/err.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/smp.h>
#include <linux/sysfs.h>
#include <linux/stat.h>
#include <linux/clk.h>
#include <linux/cpu.h>
#include <linux/coresight.h>
#include <linux/pm_wakeup.h>
#include <linux/amba/bus.h>
#include <linux/seq_file.h>
#include <linux/uaccess.h>
#include <linux/pm_runtime.h>
#include <asm/sections.h>
#include "coresight-etm4x.h"
static int boot_enable;
module_param_named(boot_enable, boot_enable, int, S_IRUGO);
/* The number of ETMv4 currently registered */
static int etm4_count;
static struct etmv4_drvdata *etmdrvdata[NR_CPUS];
static void etm4_os_unlock(void *info)
{
struct etmv4_drvdata *drvdata = (struct etmv4_drvdata *)info;
/* Writing any value to ETMOSLAR unlocks the trace registers */
writel_relaxed(0x0, drvdata->base + TRCOSLAR);
isb();
}
static bool etm4_arch_supported(u8 arch)
{
switch (arch) {
case ETM_ARCH_V4:
break;
default:
return false;
}
return true;
}
static int etm4_trace_id(struct coresight_device *csdev)
{
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
unsigned long flags;
int trace_id = -1;
if (!drvdata->enable)
return drvdata->trcid;
pm_runtime_get_sync(drvdata->dev);
spin_lock_irqsave(&drvdata->spinlock, flags);
CS_UNLOCK(drvdata->base);
trace_id = readl_relaxed(drvdata->base + TRCTRACEIDR);
trace_id &= ETM_TRACEID_MASK;
CS_LOCK(drvdata->base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
pm_runtime_put(drvdata->dev);
return trace_id;
}
static void etm4_enable_hw(void *info)
{
int i;
struct etmv4_drvdata *drvdata = info;
CS_UNLOCK(drvdata->base);
etm4_os_unlock(drvdata);
/* Disable the trace unit before programming trace registers */
writel_relaxed(0, drvdata->base + TRCPRGCTLR);
/* wait for TRCSTATR.IDLE to go up */
if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 1))
dev_err(drvdata->dev,
"timeout observed when probing at offset %#x\n",
TRCSTATR);
writel_relaxed(drvdata->pe_sel, drvdata->base + TRCPROCSELR);
writel_relaxed(drvdata->cfg, drvdata->base + TRCCONFIGR);
/* nothing specific implemented */
writel_relaxed(0x0, drvdata->base + TRCAUXCTLR);
writel_relaxed(drvdata->eventctrl0, drvdata->base + TRCEVENTCTL0R);
writel_relaxed(drvdata->eventctrl1, drvdata->base + TRCEVENTCTL1R);
writel_relaxed(drvdata->stall_ctrl, drvdata->base + TRCSTALLCTLR);
writel_relaxed(drvdata->ts_ctrl, drvdata->base + TRCTSCTLR);
writel_relaxed(drvdata->syncfreq, drvdata->base + TRCSYNCPR);
writel_relaxed(drvdata->ccctlr, drvdata->base + TRCCCCTLR);
writel_relaxed(drvdata->bb_ctrl, drvdata->base + TRCBBCTLR);
writel_relaxed(drvdata->trcid, drvdata->base + TRCTRACEIDR);
writel_relaxed(drvdata->vinst_ctrl, drvdata->base + TRCVICTLR);
writel_relaxed(drvdata->viiectlr, drvdata->base + TRCVIIECTLR);
writel_relaxed(drvdata->vissctlr,
drvdata->base + TRCVISSCTLR);
writel_relaxed(drvdata->vipcssctlr,
drvdata->base + TRCVIPCSSCTLR);
for (i = 0; i < drvdata->nrseqstate - 1; i++)
writel_relaxed(drvdata->seq_ctrl[i],
drvdata->base + TRCSEQEVRn(i));
writel_relaxed(drvdata->seq_rst, drvdata->base + TRCSEQRSTEVR);
writel_relaxed(drvdata->seq_state, drvdata->base + TRCSEQSTR);
writel_relaxed(drvdata->ext_inp, drvdata->base + TRCEXTINSELR);
for (i = 0; i < drvdata->nr_cntr; i++) {
writel_relaxed(drvdata->cntrldvr[i],
drvdata->base + TRCCNTRLDVRn(i));
writel_relaxed(drvdata->cntr_ctrl[i],
drvdata->base + TRCCNTCTLRn(i));
writel_relaxed(drvdata->cntr_val[i],
drvdata->base + TRCCNTVRn(i));
}
for (i = 0; i < drvdata->nr_resource; i++)
writel_relaxed(drvdata->res_ctrl[i],
drvdata->base + TRCRSCTLRn(i));
for (i = 0; i < drvdata->nr_ss_cmp; i++) {
writel_relaxed(drvdata->ss_ctrl[i],
drvdata->base + TRCSSCCRn(i));
writel_relaxed(drvdata->ss_status[i],
drvdata->base + TRCSSCSRn(i));
writel_relaxed(drvdata->ss_pe_cmp[i],
drvdata->base + TRCSSPCICRn(i));
}
for (i = 0; i < drvdata->nr_addr_cmp; i++) {
writeq_relaxed(drvdata->addr_val[i],
drvdata->base + TRCACVRn(i));
writeq_relaxed(drvdata->addr_acc[i],
drvdata->base + TRCACATRn(i));
}
for (i = 0; i < drvdata->numcidc; i++)
writeq_relaxed(drvdata->ctxid_val[i],
drvdata->base + TRCCIDCVRn(i));
writel_relaxed(drvdata->ctxid_mask0, drvdata->base + TRCCIDCCTLR0);
writel_relaxed(drvdata->ctxid_mask1, drvdata->base + TRCCIDCCTLR1);
for (i = 0; i < drvdata->numvmidc; i++)
writeq_relaxed(drvdata->vmid_val[i],
drvdata->base + TRCVMIDCVRn(i));
writel_relaxed(drvdata->vmid_mask0, drvdata->base + TRCVMIDCCTLR0);
writel_relaxed(drvdata->vmid_mask1, drvdata->base + TRCVMIDCCTLR1);
/* Enable the trace unit */
writel_relaxed(1, drvdata->base + TRCPRGCTLR);
/* wait for TRCSTATR.IDLE to go back down to '0' */
if (coresight_timeout(drvdata->base, TRCSTATR, TRCSTATR_IDLE_BIT, 0))
dev_err(drvdata->dev,
"timeout observed when probing at offset %#x\n",
TRCSTATR);
CS_LOCK(drvdata->base);
dev_dbg(drvdata->dev, "cpu: %d enable smp call done\n", drvdata->cpu);
}
static int etm4_enable(struct coresight_device *csdev)
{
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
int ret;
pm_runtime_get_sync(drvdata->dev);
spin_lock(&drvdata->spinlock);
/*
* Executing etm4_enable_hw on the cpu whose ETM is being enabled
* ensures that register writes occur when cpu is powered.
*/
ret = smp_call_function_single(drvdata->cpu,
etm4_enable_hw, drvdata, 1);
if (ret)
goto err;
drvdata->enable = true;
drvdata->sticky_enable = true;
spin_unlock(&drvdata->spinlock);
dev_info(drvdata->dev, "ETM tracing enabled\n");
return 0;
err:
spin_unlock(&drvdata->spinlock);
pm_runtime_put(drvdata->dev);
return ret;
}
static void etm4_disable_hw(void *info)
{
u32 control;
struct etmv4_drvdata *drvdata = info;
CS_UNLOCK(drvdata->base);
control = readl_relaxed(drvdata->base + TRCPRGCTLR);
/* EN, bit[0] Trace unit enable bit */
control &= ~0x1;
/* make sure everything completes before disabling */
mb();
isb();
writel_relaxed(control, drvdata->base + TRCPRGCTLR);
CS_LOCK(drvdata->base);
dev_dbg(drvdata->dev, "cpu: %d disable smp call done\n", drvdata->cpu);
}
static void etm4_disable(struct coresight_device *csdev)
{
struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
/*
* Taking hotplug lock here protects from clocks getting disabled
* with tracing being left on (crash scenario) if user disable occurs
* after cpu online mask indicates the cpu is offline but before the
* DYING hotplug callback is serviced by the ETM driver.
*/
get_online_cpus();
spin_lock(&drvdata->spinlock);
/*
* Executing etm4_disable_hw on the cpu whose ETM is being disabled
* ensures that register writes occur when cpu is powered.
*/
smp_call_function_single(drvdata->cpu, etm4_disable_hw, drvdata, 1);
drvdata->enable = false;
spin_unlock(&drvdata->spinlock);
put_online_cpus();
pm_runtime_put(drvdata->dev);
dev_info(drvdata->dev, "ETM tracing disabled\n");
}
static const struct coresight_ops_source etm4_source_ops = {
.trace_id = etm4_trace_id,
.enable = etm4_enable,
.disable = etm4_disable,
};
static const struct coresight_ops etm4_cs_ops = {
.source_ops = &etm4_source_ops,
};
static ssize_t cpu_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
int val;
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
val = drvdata->cpu;
return scnprintf(buf, PAGE_SIZE, "%d\n", val);
}
static DEVICE_ATTR_RO(cpu);
static struct attribute *coresight_etmv4_attrs[] = {
&dev_attr_cpu.attr,
NULL,
};
ATTRIBUTE_GROUPS(coresight_etmv4);
static void etm4_init_arch_data(void *info)
{
u32 etmidr0;
u32 etmidr1;
u32 etmidr2;
u32 etmidr3;
u32 etmidr4;
u32 etmidr5;
struct etmv4_drvdata *drvdata = info;
CS_UNLOCK(drvdata->base);
/* find all capabilities of the tracing unit */
etmidr0 = readl_relaxed(drvdata->base + TRCIDR0);
/* INSTP0, bits[2:1] P0 tracing support field */
if (BMVAL(etmidr0, 1, 1) && BMVAL(etmidr0, 2, 2))
drvdata->instrp0 = true;
else
drvdata->instrp0 = false;
/* TRCBB, bit[5] Branch broadcast tracing support bit */
if (BMVAL(etmidr0, 5, 5))
drvdata->trcbb = true;
else
drvdata->trcbb = false;
/* TRCCOND, bit[6] Conditional instruction tracing support bit */
if (BMVAL(etmidr0, 6, 6))
drvdata->trccond = true;
else
drvdata->trccond = false;
/* TRCCCI, bit[7] Cycle counting instruction bit */
if (BMVAL(etmidr0, 7, 7))
drvdata->trccci = true;
else
drvdata->trccci = false;
/* RETSTACK, bit[9] Return stack bit */
if (BMVAL(etmidr0, 9, 9))
drvdata->retstack = true;
else
drvdata->retstack = false;
/* NUMEVENT, bits[11:10] Number of events field */
drvdata->nr_event = BMVAL(etmidr0, 10, 11);
/* QSUPP, bits[16:15] Q element support field */
drvdata->q_support = BMVAL(etmidr0, 15, 16);
/* TSSIZE, bits[28:24] Global timestamp size field */
drvdata->ts_size = BMVAL(etmidr0, 24, 28);
/* base architecture of trace unit */
etmidr1 = readl_relaxed(drvdata->base + TRCIDR1);
/*
* TRCARCHMIN, bits[7:4] architecture the minor version number
* TRCARCHMAJ, bits[11:8] architecture major versin number
*/
drvdata->arch = BMVAL(etmidr1, 4, 11);
/* maximum size of resources */
etmidr2 = readl_relaxed(drvdata->base + TRCIDR2);
/* CIDSIZE, bits[9:5] Indicates the Context ID size */
drvdata->ctxid_size = BMVAL(etmidr2, 5, 9);
/* VMIDSIZE, bits[14:10] Indicates the VMID size */
drvdata->vmid_size = BMVAL(etmidr2, 10, 14);
/* CCSIZE, bits[28:25] size of the cycle counter in bits minus 12 */
drvdata->ccsize = BMVAL(etmidr2, 25, 28);
etmidr3 = readl_relaxed(drvdata->base + TRCIDR3);
/* CCITMIN, bits[11:0] minimum threshold value that can be programmed */
drvdata->ccitmin = BMVAL(etmidr3, 0, 11);
/* EXLEVEL_S, bits[19:16] Secure state instruction tracing */
drvdata->s_ex_level = BMVAL(etmidr3, 16, 19);
/* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */
drvdata->ns_ex_level = BMVAL(etmidr3, 20, 23);
/*
* TRCERR, bit[24] whether a trace unit can trace a
* system error exception.
*/
if (BMVAL(etmidr3, 24, 24))
drvdata->trc_error = true;
else
drvdata->trc_error = false;
/* SYNCPR, bit[25] implementation has a fixed synchronization period? */
if (BMVAL(etmidr3, 25, 25))
drvdata->syncpr = true;
else
drvdata->syncpr = false;
/* STALLCTL, bit[26] is stall control implemented? */
if (BMVAL(etmidr3, 26, 26))
drvdata->stallctl = true;
else
drvdata->stallctl = false;
/* SYSSTALL, bit[27] implementation can support stall control? */
if (BMVAL(etmidr3, 27, 27))
drvdata->sysstall = true;
else
drvdata->sysstall = false;
/* NUMPROC, bits[30:28] the number of PEs available for tracing */
drvdata->nr_pe = BMVAL(etmidr3, 28, 30);
/* NOOVERFLOW, bit[31] is trace overflow prevention supported */
if (BMVAL(etmidr3, 31, 31))
drvdata->nooverflow = true;
else
drvdata->nooverflow = false;
/* number of resources trace unit supports */
etmidr4 = readl_relaxed(drvdata->base + TRCIDR4);
/* NUMACPAIRS, bits[0:3] number of addr comparator pairs for tracing */
drvdata->nr_addr_cmp = BMVAL(etmidr4, 0, 3);
/* NUMPC, bits[15:12] number of PE comparator inputs for tracing */
drvdata->nr_pe_cmp = BMVAL(etmidr4, 12, 15);
/* NUMRSPAIR, bits[19:16] the number of resource pairs for tracing */
drvdata->nr_resource = BMVAL(etmidr4, 16, 19);
/*
* NUMSSCC, bits[23:20] the number of single-shot
* comparator control for tracing
*/
drvdata->nr_ss_cmp = BMVAL(etmidr4, 20, 23);
/* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */
drvdata->numcidc = BMVAL(etmidr4, 24, 27);
/* NUMVMIDC, bits[31:28] number of VMID comparators for tracing */
drvdata->numvmidc = BMVAL(etmidr4, 28, 31);
etmidr5 = readl_relaxed(drvdata->base + TRCIDR5);
/* NUMEXTIN, bits[8:0] number of external inputs implemented */
drvdata->nr_ext_inp = BMVAL(etmidr5, 0, 8);
/* TRACEIDSIZE, bits[21:16] indicates the trace ID width */
drvdata->trcid_size = BMVAL(etmidr5, 16, 21);
/* ATBTRIG, bit[22] implementation can support ATB triggers? */
if (BMVAL(etmidr5, 22, 22))
drvdata->atbtrig = true;
else
drvdata->atbtrig = false;
/*
* LPOVERRIDE, bit[23] implementation supports
* low-power state override
*/
if (BMVAL(etmidr5, 23, 23))
drvdata->lpoverride = true;
else
drvdata->lpoverride = false;
/* NUMSEQSTATE, bits[27:25] number of sequencer states implemented */
drvdata->nrseqstate = BMVAL(etmidr5, 25, 27);
/* NUMCNTR, bits[30:28] number of counters available for tracing */
drvdata->nr_cntr = BMVAL(etmidr5, 28, 30);
CS_LOCK(drvdata->base);
}
static void etm4_init_default_data(struct etmv4_drvdata *drvdata)
{
int i;
drvdata->pe_sel = 0x0;
drvdata->cfg = (ETMv4_MODE_CTXID | ETM_MODE_VMID |
ETMv4_MODE_TIMESTAMP | ETM_MODE_RETURNSTACK);
/* disable all events tracing */
drvdata->eventctrl0 = 0x0;
drvdata->eventctrl1 = 0x0;
/* disable stalling */
drvdata->stall_ctrl = 0x0;
/* disable timestamp event */
drvdata->ts_ctrl = 0x0;
/* enable trace synchronization every 4096 bytes for trace */
if (drvdata->syncpr == false)
drvdata->syncfreq = 0xC;
/*
* enable viewInst to trace everything with start-stop logic in
* started state
*/
drvdata->vinst_ctrl |= BIT(0);
/* set initial state of start-stop logic */
if (drvdata->nr_addr_cmp)
drvdata->vinst_ctrl |= BIT(9);
/* no address range filtering for ViewInst */
drvdata->viiectlr = 0x0;
/* no start-stop filtering for ViewInst */
drvdata->vissctlr = 0x0;
/* disable seq events */
for (i = 0; i < drvdata->nrseqstate-1; i++)
drvdata->seq_ctrl[i] = 0x0;
drvdata->seq_rst = 0x0;
drvdata->seq_state = 0x0;
/* disable external input events */
drvdata->ext_inp = 0x0;
for (i = 0; i < drvdata->nr_cntr; i++) {
drvdata->cntrldvr[i] = 0x0;
drvdata->cntr_ctrl[i] = 0x0;
drvdata->cntr_val[i] = 0x0;
}
for (i = 2; i < drvdata->nr_resource * 2; i++)
drvdata->res_ctrl[i] = 0x0;
for (i = 0; i < drvdata->nr_ss_cmp; i++) {
drvdata->ss_ctrl[i] = 0x0;
drvdata->ss_pe_cmp[i] = 0x0;
}
if (drvdata->nr_addr_cmp >= 1) {
drvdata->addr_val[0] = (unsigned long)_stext;
drvdata->addr_val[1] = (unsigned long)_etext;
drvdata->addr_type[0] = ETM_ADDR_TYPE_RANGE;
drvdata->addr_type[1] = ETM_ADDR_TYPE_RANGE;
}
for (i = 0; i < drvdata->numcidc; i++)
drvdata->ctxid_val[i] = 0x0;
drvdata->ctxid_mask0 = 0x0;
drvdata->ctxid_mask1 = 0x0;
for (i = 0; i < drvdata->numvmidc; i++)
drvdata->vmid_val[i] = 0x0;
drvdata->vmid_mask0 = 0x0;
drvdata->vmid_mask1 = 0x0;
/*
* A trace ID value of 0 is invalid, so let's start at some
* random value that fits in 7 bits. ETMv3.x has 0x10 so let's
* start at 0x20.
*/
drvdata->trcid = 0x20 + drvdata->cpu;
}
static int etm4_cpu_callback(struct notifier_block *nfb, unsigned long action,
void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
if (!etmdrvdata[cpu])
goto out;
switch (action & (~CPU_TASKS_FROZEN)) {
case CPU_STARTING:
spin_lock(&etmdrvdata[cpu]->spinlock);
if (!etmdrvdata[cpu]->os_unlock) {
etm4_os_unlock(etmdrvdata[cpu]);
etmdrvdata[cpu]->os_unlock = true;
}
if (etmdrvdata[cpu]->enable)
etm4_enable_hw(etmdrvdata[cpu]);
spin_unlock(&etmdrvdata[cpu]->spinlock);
break;
case CPU_ONLINE:
if (etmdrvdata[cpu]->boot_enable &&
!etmdrvdata[cpu]->sticky_enable)
coresight_enable(etmdrvdata[cpu]->csdev);
break;
case CPU_DYING:
spin_lock(&etmdrvdata[cpu]->spinlock);
if (etmdrvdata[cpu]->enable)
etm4_disable_hw(etmdrvdata[cpu]);
spin_unlock(&etmdrvdata[cpu]->spinlock);
break;
}
out:
return NOTIFY_OK;
}
static struct notifier_block etm4_cpu_notifier = {
.notifier_call = etm4_cpu_callback,
};
static int etm4_probe(struct amba_device *adev, const struct amba_id *id)
{
int ret;
void __iomem *base;
struct device *dev = &adev->dev;
struct coresight_platform_data *pdata = NULL;
struct etmv4_drvdata *drvdata;
struct resource *res = &adev->res;
struct coresight_desc *desc;
struct device_node *np = adev->dev.of_node;
desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
if (!desc)
return -ENOMEM;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
if (np) {
pdata = of_get_coresight_platform_data(dev, np);
if (IS_ERR(pdata))
return PTR_ERR(pdata);
adev->dev.platform_data = pdata;
}
drvdata->dev = &adev->dev;
dev_set_drvdata(dev, drvdata);
/* Validity for the resource is already checked by the AMBA core */
base = devm_ioremap_resource(dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
drvdata->base = base;
spin_lock_init(&drvdata->spinlock);
drvdata->cpu = pdata ? pdata->cpu : 0;
get_online_cpus();
etmdrvdata[drvdata->cpu] = drvdata;
if (!smp_call_function_single(drvdata->cpu, etm4_os_unlock, drvdata, 1))
drvdata->os_unlock = true;
if (smp_call_function_single(drvdata->cpu,
etm4_init_arch_data, drvdata, 1))
dev_err(dev, "ETM arch init failed\n");
if (!etm4_count++)
register_hotcpu_notifier(&etm4_cpu_notifier);
put_online_cpus();
if (etm4_arch_supported(drvdata->arch) == false) {
ret = -EINVAL;
goto err_arch_supported;
}
etm4_init_default_data(drvdata);
pm_runtime_put(&adev->dev);
desc->type = CORESIGHT_DEV_TYPE_SOURCE;
desc->subtype.source_subtype = CORESIGHT_DEV_SUBTYPE_SOURCE_PROC;
desc->ops = &etm4_cs_ops;
desc->pdata = pdata;
desc->dev = dev;
desc->groups = coresight_etmv4_groups;
drvdata->csdev = coresight_register(desc);
if (IS_ERR(drvdata->csdev)) {
ret = PTR_ERR(drvdata->csdev);
goto err_coresight_register;
}
dev_info(dev, "%s initialized\n", (char *)id->data);
if (boot_enable) {
coresight_enable(drvdata->csdev);
drvdata->boot_enable = true;
}
return 0;
err_arch_supported:
pm_runtime_put(&adev->dev);
err_coresight_register:
if (--etm4_count == 0)
unregister_hotcpu_notifier(&etm4_cpu_notifier);
return ret;
}
static int etm4_remove(struct amba_device *adev)
{
struct etmv4_drvdata *drvdata = amba_get_drvdata(adev);
coresight_unregister(drvdata->csdev);
if (--etm4_count == 0)
unregister_hotcpu_notifier(&etm4_cpu_notifier);
return 0;
}
static struct amba_id etm4_ids[] = {
{ /* ETM 4.0 - Qualcomm */
.id = 0x0003b95d,
.mask = 0x0003ffff,
.data = "ETM 4.0",
},
{ /* ETM 4.0 - Juno board */
.id = 0x000bb95e,
.mask = 0x000fffff,
.data = "ETM 4.0",
},
{ 0, 0},
};
static struct amba_driver etm4x_driver = {
.drv = {
.name = "coresight-etm4x",
},
.probe = etm4_probe,
.remove = etm4_remove,
.id_table = etm4_ids,
};
module_amba_driver(etm4x_driver);