linux/drivers/bus/hisi_lpc.c
John Garry 10e62b4797 bus: hisi_lpc: Add .remove method to avoid driver unbind crash
The original driver author seemed to be under the impression that a driver
cannot be removed if it does not have a .remove method. Or maybe if it is
a built-in platform driver.

This is not true. This crash can be created:

root@ubuntu:/sys/bus/platform/drivers/hisi-lpc# echo HISI0191\:00 > unbind
root@ubuntu:/sys/bus/platform/drivers/hisi-lpc# ipmitool raw 6 1
 Unable to handle kernel paging request at virtual address ffff000010035010
 Mem abort info:
   ESR = 0x96000047
   Exception class = DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
 Data abort info:
   ISV = 0, ISS = 0x00000047
   CM = 0, WnR = 1
 swapper pgtable: 4k pages, 48-bit VAs, pgdp=000000000118b000
 [ffff000010035010] pgd=0000041ffbfff003, pud=0000041ffbffe003, pmd=0000041ffbffd003, pte=0000000000000000
 Internal error: Oops: 96000047 [#1] PREEMPT SMP
 Modules linked in:
 CPU: 17 PID: 1473 Comm: ipmitool Not tainted 5.2.0-rc5-00003-gf68c53b414a3-dirty #198
 Hardware name: Huawei Taishan 2280 /D05, BIOS Hisilicon D05 IT21 Nemo 2.0 RC0 04/18/2018
 pstate: 20000085 (nzCv daIf -PAN -UAO)
 pc : hisi_lpc_target_in+0x7c/0x120
 lr : hisi_lpc_target_in+0x70/0x120
 sp : ffff00001efe3930
 x29: ffff00001efe3930 x28: ffff841f9f599200
 x27: 0000000000000002 x26: 0000000000000000
 x25: 0000000000000080 x24: 00000000000000e4
 x23: 0000000000000000 x22: 0000000000000064
 x21: ffff801fb667d280 x20: 0000000000000001
 x19: ffff00001efe39ac x18: 0000000000000000
 x17: 0000000000000000 x16: 0000000000000000
 x15: 0000000000000000 x14: 0000000000000000
 x13: 0000000000000000 x12: 0000000000000000
 x11: 0000000000000000 x10: 0000000000000000
 x9 : 0000000000000000 x8 : ffff841febe60340
 x7 : ffff801fb55c52e8 x6 : 0000000000000000
 x5 : 0000000000ffc0e3 x4 : 0000000000000001
 x3 : ffff801fb667d280 x2 : 0000000000000001
 x1 : ffff000010035010 x0 : ffff000010035000
 Call trace:
  hisi_lpc_target_in+0x7c/0x120
  hisi_lpc_comm_in+0x88/0x98
  logic_inb+0x5c/0xb8
  port_inb+0x18/0x20
  bt_event+0x38/0x808
  smi_event_handler+0x4c/0x5a0
  check_start_timer_thread.part.4+0x40/0x58
  sender+0x78/0x88
  smi_send.isra.6+0x94/0x108
  i_ipmi_request+0x2c4/0x8f8
  ipmi_request_settime+0x124/0x160
  handle_send_req+0x19c/0x208
  ipmi_ioctl+0x2c0/0x990
  do_vfs_ioctl+0xb8/0x8f8
  ksys_ioctl+0x80/0xb8
  __arm64_sys_ioctl+0x1c/0x28
  el0_svc_common.constprop.0+0x64/0x160
  el0_svc_handler+0x28/0x78
  el0_svc+0x8/0xc
 Code: 941d1511 aa0003f9 f94006a0 91004001 (b9000034)
 ---[ end trace aa842b86af7069e4 ]---

The problem here is that the host goes away but the associated logical PIO
region remains registered, as do the children devices.

Fix by adding a .remove method to tidy-up by removing the child devices
and unregistering the logical PIO region.

Cc: stable@vger.kernel.org
Fixes: adf38bb0b5 ("HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings")
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>
2019-08-13 14:54:34 +08:00

685 lines
17 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Hisilicon Limited, All Rights Reserved.
* Author: Zhichang Yuan <yuanzhichang@hisilicon.com>
* Author: Zou Rongrong <zourongrong@huawei.com>
* Author: John Garry <john.garry@huawei.com>
*/
#include <linux/acpi.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/logic_pio.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/pci.h>
#include <linux/serial_8250.h>
#include <linux/slab.h>
#define DRV_NAME "hisi-lpc"
/*
* Setting this bit means each IO operation will target a different port
* address; 0 means repeated IO operations will use the same port,
* such as BT.
*/
#define FG_INCRADDR_LPC 0x02
struct lpc_cycle_para {
unsigned int opflags;
unsigned int csize; /* data length of each operation */
};
struct hisi_lpc_dev {
spinlock_t cycle_lock;
void __iomem *membase;
struct logic_pio_hwaddr *io_host;
};
/* The max IO cycle counts supported is four per operation at maximum */
#define LPC_MAX_DWIDTH 4
#define LPC_REG_STARTUP_SIGNAL 0x00
#define LPC_REG_STARTUP_SIGNAL_START BIT(0)
#define LPC_REG_OP_STATUS 0x04
#define LPC_REG_OP_STATUS_IDLE BIT(0)
#define LPC_REG_OP_STATUS_FINISHED BIT(1)
#define LPC_REG_OP_LEN 0x10 /* LPC cycles count per start */
#define LPC_REG_CMD 0x14
#define LPC_REG_CMD_OP BIT(0) /* 0: read, 1: write */
#define LPC_REG_CMD_SAMEADDR BIT(3)
#define LPC_REG_ADDR 0x20 /* target address */
#define LPC_REG_WDATA 0x24 /* write FIFO */
#define LPC_REG_RDATA 0x28 /* read FIFO */
/* The minimal nanosecond interval for each query on LPC cycle status */
#define LPC_NSEC_PERWAIT 100
/*
* The maximum waiting time is about 128us. It is specific for stream I/O,
* such as ins.
*
* The fastest IO cycle time is about 390ns, but the worst case will wait
* for extra 256 lpc clocks, so (256 + 13) * 30ns = 8 us. The maximum burst
* cycles is 16. So, the maximum waiting time is about 128us under worst
* case.
*
* Choose 1300 as the maximum.
*/
#define LPC_MAX_WAITCNT 1300
/* About 10us. This is specific for single IO operations, such as inb */
#define LPC_PEROP_WAITCNT 100
static int wait_lpc_idle(unsigned char *mbase, unsigned int waitcnt)
{
u32 status;
do {
status = readl(mbase + LPC_REG_OP_STATUS);
if (status & LPC_REG_OP_STATUS_IDLE)
return (status & LPC_REG_OP_STATUS_FINISHED) ? 0 : -EIO;
ndelay(LPC_NSEC_PERWAIT);
} while (--waitcnt);
return -ETIME;
}
/*
* hisi_lpc_target_in - trigger a series of LPC cycles for read operation
* @lpcdev: pointer to hisi lpc device
* @para: some parameters used to control the lpc I/O operations
* @addr: the lpc I/O target port address
* @buf: where the read back data is stored
* @opcnt: how many I/O operations required, i.e. data width
*
* Returns 0 on success, non-zero on fail.
*/
static int hisi_lpc_target_in(struct hisi_lpc_dev *lpcdev,
struct lpc_cycle_para *para, unsigned long addr,
unsigned char *buf, unsigned long opcnt)
{
unsigned int cmd_word;
unsigned int waitcnt;
unsigned long flags;
int ret;
if (!buf || !opcnt || !para || !para->csize || !lpcdev)
return -EINVAL;
cmd_word = 0; /* IO mode, Read */
waitcnt = LPC_PEROP_WAITCNT;
if (!(para->opflags & FG_INCRADDR_LPC)) {
cmd_word |= LPC_REG_CMD_SAMEADDR;
waitcnt = LPC_MAX_WAITCNT;
}
/* whole operation must be atomic */
spin_lock_irqsave(&lpcdev->cycle_lock, flags);
writel_relaxed(opcnt, lpcdev->membase + LPC_REG_OP_LEN);
writel_relaxed(cmd_word, lpcdev->membase + LPC_REG_CMD);
writel_relaxed(addr, lpcdev->membase + LPC_REG_ADDR);
writel(LPC_REG_STARTUP_SIGNAL_START,
lpcdev->membase + LPC_REG_STARTUP_SIGNAL);
/* whether the operation is finished */
ret = wait_lpc_idle(lpcdev->membase, waitcnt);
if (ret) {
spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
return ret;
}
readsb(lpcdev->membase + LPC_REG_RDATA, buf, opcnt);
spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
return 0;
}
/*
* hisi_lpc_target_out - trigger a series of LPC cycles for write operation
* @lpcdev: pointer to hisi lpc device
* @para: some parameters used to control the lpc I/O operations
* @addr: the lpc I/O target port address
* @buf: where the data to be written is stored
* @opcnt: how many I/O operations required, i.e. data width
*
* Returns 0 on success, non-zero on fail.
*/
static int hisi_lpc_target_out(struct hisi_lpc_dev *lpcdev,
struct lpc_cycle_para *para, unsigned long addr,
const unsigned char *buf, unsigned long opcnt)
{
unsigned int waitcnt;
unsigned long flags;
u32 cmd_word;
int ret;
if (!buf || !opcnt || !para || !lpcdev)
return -EINVAL;
/* default is increasing address */
cmd_word = LPC_REG_CMD_OP; /* IO mode, write */
waitcnt = LPC_PEROP_WAITCNT;
if (!(para->opflags & FG_INCRADDR_LPC)) {
cmd_word |= LPC_REG_CMD_SAMEADDR;
waitcnt = LPC_MAX_WAITCNT;
}
spin_lock_irqsave(&lpcdev->cycle_lock, flags);
writel_relaxed(opcnt, lpcdev->membase + LPC_REG_OP_LEN);
writel_relaxed(cmd_word, lpcdev->membase + LPC_REG_CMD);
writel_relaxed(addr, lpcdev->membase + LPC_REG_ADDR);
writesb(lpcdev->membase + LPC_REG_WDATA, buf, opcnt);
writel(LPC_REG_STARTUP_SIGNAL_START,
lpcdev->membase + LPC_REG_STARTUP_SIGNAL);
/* whether the operation is finished */
ret = wait_lpc_idle(lpcdev->membase, waitcnt);
spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
return ret;
}
static unsigned long hisi_lpc_pio_to_addr(struct hisi_lpc_dev *lpcdev,
unsigned long pio)
{
return pio - lpcdev->io_host->io_start + lpcdev->io_host->hw_start;
}
/*
* hisi_lpc_comm_in - input the data in a single operation
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @dwidth: the data length required to read from the target I/O port
*
* When success, data is returned. Otherwise, ~0 is returned.
*/
static u32 hisi_lpc_comm_in(void *hostdata, unsigned long pio, size_t dwidth)
{
struct hisi_lpc_dev *lpcdev = hostdata;
struct lpc_cycle_para iopara;
unsigned long addr;
u32 rd_data = 0;
int ret;
if (!lpcdev || !dwidth || dwidth > LPC_MAX_DWIDTH)
return ~0;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
iopara.opflags = FG_INCRADDR_LPC;
iopara.csize = dwidth;
ret = hisi_lpc_target_in(lpcdev, &iopara, addr,
(unsigned char *)&rd_data, dwidth);
if (ret)
return ~0;
return le32_to_cpu(rd_data);
}
/*
* hisi_lpc_comm_out - output the data in a single operation
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @val: a value to be output from caller, maximum is four bytes
* @dwidth: the data width required writing to the target I/O port
*
* This function corresponds to out(b,w,l) only.
*/
static void hisi_lpc_comm_out(void *hostdata, unsigned long pio,
u32 val, size_t dwidth)
{
struct hisi_lpc_dev *lpcdev = hostdata;
struct lpc_cycle_para iopara;
const unsigned char *buf;
unsigned long addr;
if (!lpcdev || !dwidth || dwidth > LPC_MAX_DWIDTH)
return;
val = cpu_to_le32(val);
buf = (const unsigned char *)&val;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
iopara.opflags = FG_INCRADDR_LPC;
iopara.csize = dwidth;
hisi_lpc_target_out(lpcdev, &iopara, addr, buf, dwidth);
}
/*
* hisi_lpc_comm_ins - input the data in the buffer in multiple operations
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @buffer: a buffer where read/input data bytes are stored
* @dwidth: the data width required writing to the target I/O port
* @count: how many data units whose length is dwidth will be read
*
* When success, the data read back is stored in buffer pointed by buffer.
* Returns 0 on success, -errno otherwise.
*/
static u32 hisi_lpc_comm_ins(void *hostdata, unsigned long pio, void *buffer,
size_t dwidth, unsigned int count)
{
struct hisi_lpc_dev *lpcdev = hostdata;
unsigned char *buf = buffer;
struct lpc_cycle_para iopara;
unsigned long addr;
if (!lpcdev || !buf || !count || !dwidth || dwidth > LPC_MAX_DWIDTH)
return -EINVAL;
iopara.opflags = 0;
if (dwidth > 1)
iopara.opflags |= FG_INCRADDR_LPC;
iopara.csize = dwidth;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
do {
int ret;
ret = hisi_lpc_target_in(lpcdev, &iopara, addr, buf, dwidth);
if (ret)
return ret;
buf += dwidth;
} while (--count);
return 0;
}
/*
* hisi_lpc_comm_outs - output the data in the buffer in multiple operations
* @hostdata: pointer to the device information relevant to LPC controller
* @pio: the target I/O port address
* @buffer: a buffer where write/output data bytes are stored
* @dwidth: the data width required writing to the target I/O port
* @count: how many data units whose length is dwidth will be written
*/
static void hisi_lpc_comm_outs(void *hostdata, unsigned long pio,
const void *buffer, size_t dwidth,
unsigned int count)
{
struct hisi_lpc_dev *lpcdev = hostdata;
struct lpc_cycle_para iopara;
const unsigned char *buf = buffer;
unsigned long addr;
if (!lpcdev || !buf || !count || !dwidth || dwidth > LPC_MAX_DWIDTH)
return;
iopara.opflags = 0;
if (dwidth > 1)
iopara.opflags |= FG_INCRADDR_LPC;
iopara.csize = dwidth;
addr = hisi_lpc_pio_to_addr(lpcdev, pio);
do {
if (hisi_lpc_target_out(lpcdev, &iopara, addr, buf, dwidth))
break;
buf += dwidth;
} while (--count);
}
static const struct logic_pio_host_ops hisi_lpc_ops = {
.in = hisi_lpc_comm_in,
.out = hisi_lpc_comm_out,
.ins = hisi_lpc_comm_ins,
.outs = hisi_lpc_comm_outs,
};
#ifdef CONFIG_ACPI
static int hisi_lpc_acpi_xlat_io_res(struct acpi_device *adev,
struct acpi_device *host,
struct resource *res)
{
unsigned long sys_port;
resource_size_t len = resource_size(res);
sys_port = logic_pio_trans_hwaddr(&host->fwnode, res->start, len);
if (sys_port == ~0UL)
return -EFAULT;
res->start = sys_port;
res->end = sys_port + len;
return 0;
}
/*
* hisi_lpc_acpi_set_io_res - set the resources for a child
* @child: the device node to be updated the I/O resource
* @hostdev: the device node associated with host controller
* @res: double pointer to be set to the address of translated resources
* @num_res: pointer to variable to hold the number of translated resources
*
* Returns 0 when successful, and a negative value for failure.
*
* For a given host controller, each child device will have an associated
* host-relative address resource. This function will return the translated
* logical PIO addresses for each child devices resources.
*/
static int hisi_lpc_acpi_set_io_res(struct device *child,
struct device *hostdev,
const struct resource **res, int *num_res)
{
struct acpi_device *adev;
struct acpi_device *host;
struct resource_entry *rentry;
LIST_HEAD(resource_list);
struct resource *resources;
int count;
int i;
if (!child || !hostdev)
return -EINVAL;
host = to_acpi_device(hostdev);
adev = to_acpi_device(child);
if (!adev->status.present) {
dev_dbg(child, "device is not present\n");
return -EIO;
}
if (acpi_device_enumerated(adev)) {
dev_dbg(child, "has been enumerated\n");
return -EIO;
}
/*
* The following code segment to retrieve the resources is common to
* acpi_create_platform_device(), so consider a common helper function
* in future.
*/
count = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
if (count <= 0) {
dev_dbg(child, "failed to get resources\n");
return count ? count : -EIO;
}
resources = devm_kcalloc(hostdev, count, sizeof(*resources),
GFP_KERNEL);
if (!resources) {
dev_warn(hostdev, "could not allocate memory for %d resources\n",
count);
acpi_dev_free_resource_list(&resource_list);
return -ENOMEM;
}
count = 0;
list_for_each_entry(rentry, &resource_list, node)
resources[count++] = *rentry->res;
acpi_dev_free_resource_list(&resource_list);
/* translate the I/O resources */
for (i = 0; i < count; i++) {
int ret;
if (!(resources[i].flags & IORESOURCE_IO))
continue;
ret = hisi_lpc_acpi_xlat_io_res(adev, host, &resources[i]);
if (ret) {
dev_err(child, "translate IO range %pR failed (%d)\n",
&resources[i], ret);
return ret;
}
}
*res = resources;
*num_res = count;
return 0;
}
static int hisi_lpc_acpi_remove_subdev(struct device *dev, void *unused)
{
platform_device_unregister(to_platform_device(dev));
return 0;
}
struct hisi_lpc_acpi_cell {
const char *hid;
const char *name;
void *pdata;
size_t pdata_size;
};
static void hisi_lpc_acpi_remove(struct device *hostdev)
{
struct acpi_device *adev = ACPI_COMPANION(hostdev);
struct acpi_device *child;
device_for_each_child(hostdev, NULL, hisi_lpc_acpi_remove_subdev);
list_for_each_entry(child, &adev->children, node)
acpi_device_clear_enumerated(child);
}
/*
* hisi_lpc_acpi_probe - probe children for ACPI FW
* @hostdev: LPC host device pointer
*
* Returns 0 when successful, and a negative value for failure.
*
* Create a platform device per child, fixing up the resources
* from bus addresses to Logical PIO addresses.
*
*/
static int hisi_lpc_acpi_probe(struct device *hostdev)
{
struct acpi_device *adev = ACPI_COMPANION(hostdev);
struct acpi_device *child;
int ret;
/* Only consider the children of the host */
list_for_each_entry(child, &adev->children, node) {
const char *hid = acpi_device_hid(child);
const struct hisi_lpc_acpi_cell *cell;
struct platform_device *pdev;
const struct resource *res;
bool found = false;
int num_res;
ret = hisi_lpc_acpi_set_io_res(&child->dev, &adev->dev, &res,
&num_res);
if (ret) {
dev_warn(hostdev, "set resource fail (%d)\n", ret);
goto fail;
}
cell = (struct hisi_lpc_acpi_cell []){
/* ipmi */
{
.hid = "IPI0001",
.name = "hisi-lpc-ipmi",
},
/* 8250-compatible uart */
{
.hid = "HISI1031",
.name = "serial8250",
.pdata = (struct plat_serial8250_port []) {
{
.iobase = res->start,
.uartclk = 1843200,
.iotype = UPIO_PORT,
.flags = UPF_BOOT_AUTOCONF,
},
{}
},
.pdata_size = 2 *
sizeof(struct plat_serial8250_port),
},
{}
};
for (; cell && cell->name; cell++) {
if (!strcmp(cell->hid, hid)) {
found = true;
break;
}
}
if (!found) {
dev_warn(hostdev,
"could not find cell for child device (%s), discarding\n",
hid);
continue;
}
pdev = platform_device_alloc(cell->name, PLATFORM_DEVID_AUTO);
if (!pdev) {
ret = -ENOMEM;
goto fail;
}
pdev->dev.parent = hostdev;
ACPI_COMPANION_SET(&pdev->dev, child);
ret = platform_device_add_resources(pdev, res, num_res);
if (ret)
goto fail;
ret = platform_device_add_data(pdev, cell->pdata,
cell->pdata_size);
if (ret)
goto fail;
ret = platform_device_add(pdev);
if (ret)
goto fail;
acpi_device_set_enumerated(child);
}
return 0;
fail:
hisi_lpc_acpi_remove(hostdev);
return ret;
}
static const struct acpi_device_id hisi_lpc_acpi_match[] = {
{"HISI0191"},
{}
};
#else
static int hisi_lpc_acpi_probe(struct device *dev)
{
return -ENODEV;
}
static void hisi_lpc_acpi_remove(struct device *hostdev)
{
}
#endif // CONFIG_ACPI
/*
* hisi_lpc_probe - the probe callback function for hisi lpc host,
* will finish all the initialization.
* @pdev: the platform device corresponding to hisi lpc host
*
* Returns 0 on success, non-zero on fail.
*/
static int hisi_lpc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct acpi_device *acpi_device = ACPI_COMPANION(dev);
struct logic_pio_hwaddr *range;
struct hisi_lpc_dev *lpcdev;
resource_size_t io_end;
struct resource *res;
int ret;
lpcdev = devm_kzalloc(dev, sizeof(*lpcdev), GFP_KERNEL);
if (!lpcdev)
return -ENOMEM;
spin_lock_init(&lpcdev->cycle_lock);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
lpcdev->membase = devm_ioremap_resource(dev, res);
if (IS_ERR(lpcdev->membase))
return PTR_ERR(lpcdev->membase);
range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL);
if (!range)
return -ENOMEM;
range->fwnode = dev->fwnode;
range->flags = LOGIC_PIO_INDIRECT;
range->size = PIO_INDIRECT_SIZE;
range->hostdata = lpcdev;
range->ops = &hisi_lpc_ops;
lpcdev->io_host = range;
ret = logic_pio_register_range(range);
if (ret) {
dev_err(dev, "register IO range failed (%d)!\n", ret);
return ret;
}
/* register the LPC host PIO resources */
if (acpi_device)
ret = hisi_lpc_acpi_probe(dev);
else
ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
if (ret) {
logic_pio_unregister_range(range);
return ret;
}
dev_set_drvdata(dev, lpcdev);
io_end = lpcdev->io_host->io_start + lpcdev->io_host->size;
dev_info(dev, "registered range [%pa - %pa]\n",
&lpcdev->io_host->io_start, &io_end);
return ret;
}
static int hisi_lpc_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct acpi_device *acpi_device = ACPI_COMPANION(dev);
struct hisi_lpc_dev *lpcdev = dev_get_drvdata(dev);
struct logic_pio_hwaddr *range = lpcdev->io_host;
if (acpi_device)
hisi_lpc_acpi_remove(dev);
else
of_platform_depopulate(dev);
logic_pio_unregister_range(range);
return 0;
}
static const struct of_device_id hisi_lpc_of_match[] = {
{ .compatible = "hisilicon,hip06-lpc", },
{ .compatible = "hisilicon,hip07-lpc", },
{}
};
static struct platform_driver hisi_lpc_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = hisi_lpc_of_match,
.acpi_match_table = ACPI_PTR(hisi_lpc_acpi_match),
},
.probe = hisi_lpc_probe,
.remove = hisi_lpc_remove,
};
builtin_platform_driver(hisi_lpc_driver);