diff mbox series

[v11,6/9] LPC: Support the LPC host on Hip06/Hip07 with DT bindings

Message ID 1516537647-50553-7-git-send-email-john.garry@huawei.com
State Superseded
Headers show
Series LPC: legacy ISA I/O support | expand

Commit Message

John Garry Jan. 21, 2018, 12:27 p.m. UTC
From: Zhichang Yuan <yuanzhichang@hisilicon.com>

The low-pin-count(LPC) interface of Hip06/Hip07 accesses the peripherals in
I/O port addresses. This patch implements the LPC host controller driver
which perform the I/O operations on the underlying hardware.
We don't want to touch those existing peripherals' driver, such as ipmi-bt.
So this driver applies the indirect-IO introduced in the previous patch
after registering an indirect-IO node to the indirect-IO devices list which
will be searched in the I/O accessors to retrieve the host-local I/O port.

Signed-off-by: Zou Rongrong <zourongrong@huawei.com>
Signed-off-by: Zhichang Yuan <yuanzhichang@hisilicon.com>
Signed-off-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>
Acked-by: Rob Herring <robh@kernel.org> #dts part
---
 .../arm/hisilicon/hisilicon-low-pin-count.txt      |  33 ++
 drivers/bus/Kconfig                                |   8 +
 drivers/bus/Makefile                               |   1 +
 drivers/bus/hisi_lpc.c                             | 526 +++++++++++++++++++++
 4 files changed, 568 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/arm/hisilicon/hisilicon-low-pin-count.txt
 create mode 100644 drivers/bus/hisi_lpc.c

Comments

Randy Dunlap Jan. 21, 2018, 5:54 p.m. UTC | #1
On 01/21/2018 04:27 AM, John Garry wrote:
> diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
> index 57e011d..91debe4 100644
> --- a/drivers/bus/Kconfig
> +++ b/drivers/bus/Kconfig
> @@ -65,6 +65,14 @@ config BRCMSTB_GISB_ARB
>  	  arbiter. This driver provides timeout and target abort error handling
>  	  and internal bus master decoding.
>  
> +config HISILICON_LPC
> +	bool "Support for ISA I/O space on Hisilicon hip06/7"
> +	depends on (ARM64 && (ARCH_HISI || COMPILE_TEST))
> +	select INDIRECT_PIO
> +	help
> +	  Driver needed for some legacy ISA devices attached to Low-Pin-Count
> +	  on Hisilicon hip06/7 SoC.

Hi,
Why is this config symbol bool instead of tristate?

thanks,
John Garry Jan. 22, 2018, 10:13 a.m. UTC | #2
On 21/01/2018 17:54, Randy Dunlap wrote:
> On 01/21/2018 04:27 AM, John Garry wrote:
>> diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
>> index 57e011d..91debe4 100644
>> --- a/drivers/bus/Kconfig
>> +++ b/drivers/bus/Kconfig
>> @@ -65,6 +65,14 @@ config BRCMSTB_GISB_ARB
>>  	  arbiter. This driver provides timeout and target abort error handling
>>  	  and internal bus master decoding.
>>
>> +config HISILICON_LPC
>> +	bool "Support for ISA I/O space on Hisilicon hip06/7"
>> +	depends on (ARM64 && (ARCH_HISI || COMPILE_TEST))
>> +	select INDIRECT_PIO
>> +	help
>> +	  Driver needed for some legacy ISA devices attached to Low-Pin-Count
>> +	  on Hisilicon hip06/7 SoC.
>
> Hi,
> Why is this config symbol bool instead of tristate?
>
> thanks,

Hi Randy,

Considering the nature of this driver, and the fact that it provides an 
IO space region through the logical PIO framework introduced, it does 
not make sense to have it as a loadable module.

A specific issue is that one of our boards uses this host for the UART 
console (through 8250-compatible device in BMC), so would want it in the 
kernel image.

I will add a note in the commit message and maybe config description 
explaining this.

Thanks,
John

>
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/arm/hisilicon/hisilicon-low-pin-count.txt b/Documentation/devicetree/bindings/arm/hisilicon/hisilicon-low-pin-count.txt
new file mode 100644
index 0000000..213181f
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/hisilicon/hisilicon-low-pin-count.txt
@@ -0,0 +1,33 @@ 
+Hisilicon Hip06 low-pin-count device
+  Hisilicon Hip06 SoCs implement a Low Pin Count (LPC) controller, which
+  provides I/O access to some legacy ISA devices.
+  Hip06 is based on arm64 architecture where there is no I/O space. So, the
+  I/O ports here are not cpu addresses, and there is no 'ranges' property in
+  LPC device node.
+
+Required properties:
+- compatible:  value should be as follows:
+	(a) "hisilicon,hip06-lpc"
+	(b) "hisilicon,hip07-lpc"
+- #address-cells: must be 2 which stick to the ISA/EISA binding doc.
+- #size-cells: must be 1 which stick to the ISA/EISA binding doc.
+- reg: base memory range where the LPC register set is mapped.
+
+Note:
+  The node name before '@' must be "isa" to represent the binding stick to the
+  ISA/EISA binding specification.
+
+Example:
+
+isa@a01b0000 {
+	compatible = "hisilicon,hip06-lpc";
+	#address-cells = <2>;
+	#size-cells = <1>;
+	reg = <0x0 0xa01b0000 0x0 0x1000>;
+
+	ipmi0: bt@e4 {
+		compatible = "ipmi-bt";
+		device_type = "ipmi";
+		reg = <0x01 0xe4 0x04>;
+	};
+};
diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 57e011d..91debe4 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -65,6 +65,14 @@  config BRCMSTB_GISB_ARB
 	  arbiter. This driver provides timeout and target abort error handling
 	  and internal bus master decoding.
 
+config HISILICON_LPC
+	bool "Support for ISA I/O space on Hisilicon hip06/7"
+	depends on (ARM64 && (ARCH_HISI || COMPILE_TEST))
+	select INDIRECT_PIO
+	help
+	  Driver needed for some legacy ISA devices attached to Low-Pin-Count
+	  on Hisilicon hip06/7 SoC.
+
 config IMX_WEIM
 	bool "Freescale EIM DRIVER"
 	depends on ARCH_MXC
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index 9bcd0bf..abc7a42 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -8,6 +8,7 @@  obj-$(CONFIG_ARM_CCI)		+= arm-cci.o
 obj-$(CONFIG_ARM_CCN)		+= arm-ccn.o
 
 obj-$(CONFIG_BRCMSTB_GISB_ARB)	+= brcmstb_gisb.o
+obj-$(CONFIG_HISILICON_LPC)	+= hisi_lpc.o
 obj-$(CONFIG_IMX_WEIM)		+= imx-weim.o
 obj-$(CONFIG_MIPS_CDMM)		+= mips_cdmm.o
 obj-$(CONFIG_MVEBU_MBUS) 	+= mvebu-mbus.o
diff --git a/drivers/bus/hisi_lpc.c b/drivers/bus/hisi_lpc.c
new file mode 100644
index 0000000..4ce089a
--- /dev/null
+++ b/drivers/bus/hisi_lpc.c
@@ -0,0 +1,526 @@ 
+/*
+ * Copyright (C) 2017 Hisilicon Limited, All Rights Reserved.
+ * Author: Zhichang Yuan <yuanzhichang@hisilicon.com>
+ * Author: Zou Rongrong <zourongrong@huawei.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#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/slab.h>
+
+#define LPC_MIN_BUS_RANGE	0x0
+
+/*
+ * The default maximal IO size for Hip06/Hip07 LPC bus.
+ * Defining the I/O range size as 0x4000 here should be sufficient for
+ * all peripherals under the bus.
+ */
+#define LPC_BUS_IO_SIZE		0x4000
+
+/*
+ * Setting this bit means each IO operation will target to a
+ * different port address:
+ * 0 means repeatedly IO operations will stick on the same port,
+ * such as BT;
+ */
+#define FG_INCRADDR_LPC		0x02
+
+struct lpc_cycle_para {
+	unsigned int opflags;
+	unsigned int csize; /* the data length of each operation */
+};
+
+struct hisilpc_dev {
+	spinlock_t cycle_lock;
+	void __iomem  *membase;
+	struct logic_pio_hwaddr *io_host;
+};
+
+/* The maximum continuous cycles per burst */
+#define LPC_MAX_BURST	16
+/* The IO cycle counts supported is four per operation at maximum */
+#define LPC_MAX_DULEN	4
+#if LPC_MAX_DULEN > LPC_MAX_BURST
+#error "LPC.. MAX_DULEN must be not bigger than MAX_OPCNT!"
+#endif
+
+#if LPC_MAX_BURST % LPC_MAX_DULEN
+#error "LPC.. LPC_MAX_BURST must be multiple of LPC_MAX_DULEN!"
+#endif
+
+#define LPC_REG_START		0x00 /* start a new LPC cycle */
+#define LPC_REG_OP_STATUS	0x04 /* the current LPC status */
+#define LPC_REG_IRQ_ST		0x08 /* interrupt enable&status */
+#define LPC_REG_OP_LEN		0x10 /* how many LPC cycles each start */
+#define LPC_REG_CMD		0x14 /* command for the required LPC cycle */
+#define LPC_REG_ADDR		0x20 /* LPC target address */
+#define LPC_REG_WDATA		0x24 /* data to be written */
+#define LPC_REG_RDATA		0x28 /* data coming from peer */
+
+
+/* The command register fields */
+#define LPC_CMD_SAMEADDR	0x08
+#define LPC_CMD_TYPE_IO		0x00
+#define LPC_CMD_WRITE		0x01
+#define LPC_CMD_READ		0x00
+/* the bit attribute is W1C. 1 represents OK. */
+#define LPC_STAT_BYIRQ		0x02
+
+#define LPC_STATUS_IDLE		0x01
+#define LPC_OP_FINISHED		0x02
+
+#define LPC_START_WORK		0x01
+
+/* 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 operation, such as inb. */
+#define LPC_PEROP_WAITCNT	100
+
+static inline int wait_lpc_idle(unsigned char *mbase,
+				unsigned int waitcnt) {
+	u32 opstatus;
+
+	while (waitcnt--) {
+		ndelay(LPC_NSEC_PERWAIT);
+		opstatus = readl(mbase + LPC_REG_OP_STATUS);
+		if (opstatus & LPC_STATUS_IDLE)
+			return (opstatus & LPC_OP_FINISHED) ? 0 : (-EIO);
+	}
+	return -ETIME;
+}
+
+/*
+ * hisilpc_target_in - trigger a series of lpc cycles to read required data
+ *		       from target peripheral.
+ * @lpcdev: pointer to hisi lpc device
+ * @para: some parameters used to control the lpc I/O operations
+ * @ptaddr: the lpc I/O target port address
+ * @buf: where the read back data is stored
+ * @opcnt: how many I/O operations required in this calling
+ *
+ * Only one byte data is read each I/O operation.
+ *
+ * Returns 0 on success, non-zero on fail.
+ */
+static int
+hisilpc_target_in(struct hisilpc_dev *lpcdev, struct lpc_cycle_para *para,
+		  unsigned long ptaddr, unsigned char *buf,
+		  unsigned long opcnt)
+{
+	unsigned long cnt_per_trans;
+	unsigned int cmd_word;
+	unsigned int waitcnt;
+	int ret;
+
+	if (!buf || !opcnt || !para || !para->csize || !lpcdev)
+		return -EINVAL;
+
+	cmd_word = LPC_CMD_TYPE_IO | LPC_CMD_READ;
+	waitcnt = LPC_PEROP_WAITCNT;
+	if (!(para->opflags & FG_INCRADDR_LPC)) {
+		cmd_word |= LPC_CMD_SAMEADDR;
+		waitcnt = LPC_MAX_WAITCNT;
+	}
+
+	ret = 0;
+	cnt_per_trans = (para->csize == 1) ? opcnt : para->csize;
+	for (; opcnt && !ret; cnt_per_trans = para->csize) {
+		unsigned long flags;
+
+		/* whole operation must be atomic */
+		spin_lock_irqsave(&lpcdev->cycle_lock, flags);
+
+		writel_relaxed(cnt_per_trans, lpcdev->membase + LPC_REG_OP_LEN);
+
+		writel_relaxed(cmd_word, lpcdev->membase + LPC_REG_CMD);
+
+		writel_relaxed(ptaddr, lpcdev->membase + LPC_REG_ADDR);
+
+		writel(LPC_START_WORK, lpcdev->membase + LPC_REG_START);
+
+		/* whether the operation is finished */
+		ret = wait_lpc_idle(lpcdev->membase, waitcnt);
+		if (!ret) {
+			opcnt -= cnt_per_trans;
+			for (cnt_per_trans--; cnt_per_trans--; buf++)
+				*buf = readb_relaxed(lpcdev->membase +
+					LPC_REG_RDATA);
+			*buf = readb(lpcdev->membase + LPC_REG_RDATA);
+		}
+
+		spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
+	}
+
+	return ret;
+}
+
+/*
+ * hisilpc_target_out - trigger a series of lpc cycles to write required
+ *			data to target peripheral.
+ * @lpcdev: pointer to hisi lpc device
+ * @para: some parameters used to control the lpc I/O operations
+ * @ptaddr: the lpc I/O target port address
+ * @buf: where the data to be written is stored
+ * @opcnt: how many I/O operations required
+ *
+ * Only one byte data is read each I/O operation.
+ *
+ * Returns 0 on success, non-zero on fail.
+ *
+ */
+static int
+hisilpc_target_out(struct hisilpc_dev *lpcdev, struct lpc_cycle_para *para,
+		   unsigned long ptaddr, const unsigned char *buf,
+		   unsigned long opcnt)
+{
+	unsigned long cnt_per_trans;
+	unsigned int cmd_word;
+	unsigned int waitcnt;
+	int ret;
+
+	if (!buf || !opcnt || !para || !lpcdev)
+		return -EINVAL;
+
+	/* default is increasing address */
+	cmd_word = LPC_CMD_TYPE_IO | LPC_CMD_WRITE;
+	waitcnt = LPC_PEROP_WAITCNT;
+	if (!(para->opflags & FG_INCRADDR_LPC)) {
+		cmd_word |= LPC_CMD_SAMEADDR;
+		waitcnt = LPC_MAX_WAITCNT;
+	}
+
+	ret = 0;
+	cnt_per_trans = (para->csize == 1) ? opcnt : para->csize;
+	for (; opcnt && !ret; cnt_per_trans = para->csize) {
+		unsigned long flags;
+
+		spin_lock_irqsave(&lpcdev->cycle_lock, flags);
+
+		writel_relaxed(cnt_per_trans, lpcdev->membase + LPC_REG_OP_LEN);
+		writel_relaxed(cmd_word, lpcdev->membase + LPC_REG_CMD);
+		writel_relaxed(ptaddr, lpcdev->membase + LPC_REG_ADDR);
+
+		opcnt -= cnt_per_trans;
+		for (; cnt_per_trans--; buf++)
+			writeb_relaxed(*buf, lpcdev->membase + LPC_REG_WDATA);
+
+		writel(LPC_START_WORK, lpcdev->membase + LPC_REG_START);
+
+		/* whether the operation is finished */
+		ret = wait_lpc_idle(lpcdev->membase, waitcnt);
+
+		spin_unlock_irqrestore(&lpcdev->cycle_lock, flags);
+	}
+
+	return ret;
+}
+
+static inline unsigned long
+hisi_lpc_pio_to_addr(struct hisilpc_dev *lpcdev, unsigned long pio)
+{
+	return pio - lpcdev->io_host->io_start +
+		lpcdev->io_host->hw_start;
+}
+
+
+/**
+ * hisilpc_comm_in - read/input the data from the I/O peripheral
+ *		     through LPC.
+ * @devobj: pointer to the device information relevant to LPC controller.
+ * @pio: the target I/O port address.
+ * @dlen: the data length required to read from the target I/O port.
+ *
+ * when succeed, the data read back is stored in buffer pointed by inbuf.
+ * For inb, return the data read from I/O or -1 when error occur.
+ */
+static u32 hisilpc_comm_in(void *devobj, unsigned long pio, size_t dlen)
+{
+	int ret = 0;
+	unsigned char rd_data = 0;
+	unsigned long ptaddr;
+	struct lpc_cycle_para iopara;
+	struct hisilpc_dev *lpcdev = devobj;
+
+	if (!lpcdev || !dlen || dlen > LPC_MAX_DULEN)
+		return -1;
+
+	ptaddr = hisi_lpc_pio_to_addr(lpcdev, pio);
+
+	iopara.opflags = FG_INCRADDR_LPC;
+	iopara.csize = dlen;
+
+	ret = hisilpc_target_in(lpcdev, &iopara, ptaddr, &rd_data, dlen);
+	if (ret)
+		return -1;
+
+	return le32_to_cpu((u32)rd_data);
+}
+
+/**
+ * hisilpc_comm_out - output the data whose maximum length is four bytes
+		      to the I/O peripheral through the LPC host.
+ * @devobj: pointer to the device information relevant to LPC controller.
+ * @pio: the target I/O port address.
+ * @outval: a value to be outputted from caller, maximum is four bytes.
+ * @dlen: the data length required writing to the target I/O port.
+ *
+ * This function is corresponding to out(b,w,l) only
+ *
+ */
+static void hisilpc_comm_out(void *devobj, unsigned long pio,
+			     u32 outval, size_t dlen)
+{
+	unsigned long ptaddr;
+	struct hisilpc_dev *lpcdev = devobj;
+	struct lpc_cycle_para iopara;
+	const unsigned char *newbuf;
+
+	if (!lpcdev || !dlen || dlen > LPC_MAX_DULEN)
+		return;
+
+	outval = cpu_to_le32(outval);
+
+	newbuf = (const unsigned char *)&outval;
+	ptaddr = hisi_lpc_pio_to_addr(lpcdev, pio);
+
+	iopara.opflags = FG_INCRADDR_LPC;
+	iopara.csize = dlen;
+
+	hisilpc_target_out(lpcdev, &iopara, ptaddr, newbuf, dlen);
+}
+
+/*
+ * hisilpc_comm_ins - read/input the data in buffer to the I/O
+ *		peripheral through LPC, it corresponds to ins(b,w,l)
+ * @devobj: pointer to the device information relevant to LPC controller.
+ * @pio: the target I/O port address.
+ * @inbuf: a buffer where read/input data bytes are stored.
+ * @dlen: the data length required writing to the target I/O port.
+ * @count: how many data units whose length is dlen will be read.
+ *
+ * when succeed, the data read back is stored in buffer pointed by inbuf.
+ * Returns 0 on success, -errno otherwise
+ *
+ */
+static u32
+hisilpc_comm_ins(void *devobj, unsigned long pio, void *inbuf,
+		 size_t dlen, unsigned int count)
+{
+	struct hisilpc_dev *lpcdev = devobj;
+	struct lpc_cycle_para iopara;
+	unsigned char *newbuf;
+	unsigned int loopcnt, cntleft;
+	unsigned long ptaddr;
+
+	if (!lpcdev || !inbuf || !count || !dlen || dlen > LPC_MAX_DULEN ||
+			count % dlen)
+		return -EINVAL;
+
+	iopara.opflags = 0;
+	if (dlen > 1)
+		iopara.opflags |= FG_INCRADDR_LPC;
+	iopara.csize = dlen;
+
+	ptaddr = hisi_lpc_pio_to_addr(lpcdev, pio);
+	newbuf = inbuf;
+	/*
+	 * ensure data stream whose length is multiple of dlen to be processed
+	 * each IO input
+	 */
+	cntleft = count * dlen;
+	do {
+		int ret;
+
+		loopcnt = min_t(unsigned int, LPC_MAX_BURST, cntleft);
+		ret = hisilpc_target_in(lpcdev, &iopara, ptaddr,
+					newbuf, loopcnt);
+		if (ret)
+			return ret;
+		newbuf += loopcnt;
+		cntleft -= loopcnt;
+	} while (cntleft);
+
+	return 0;
+}
+
+/*
+ * hisilpc_comm_outs - write/output the data in buffer to the I/O
+ *		peripheral through LPC, it corresponds to outs(b,w,l)
+ * @devobj: pointer to the device information relevant to LPC controller.
+ * @pio: the target I/O port address.
+ * @outbuf: a buffer where write/output data bytes are stored.
+ * @dlen: the data length required writing to the target I/O port .
+ * @count: how many data units whose length is dlen will be written.
+ *
+ */
+static void
+hisilpc_comm_outs(void *devobj, unsigned long pio, const void *outbuf,
+		  size_t dlen, unsigned int count)
+{
+	struct hisilpc_dev *lpcdev = devobj;
+	struct lpc_cycle_para iopara;
+	const unsigned char *newbuf;
+	unsigned int loopcnt, cntleft;
+	unsigned long ptaddr;
+
+	if (!lpcdev || !outbuf || !count || !dlen || dlen > LPC_MAX_DULEN ||
+			count % dlen)
+		return;
+
+	iopara.opflags = 0;
+	if (dlen > 1)
+		iopara.opflags |= FG_INCRADDR_LPC;
+	iopara.csize = dlen;
+
+	ptaddr = hisi_lpc_pio_to_addr(lpcdev, pio);
+	newbuf = outbuf;
+	/*
+	 * ensure data stream whose length is multiple of dlen to be processed
+	 * each IO input
+	 */
+	cntleft = count * dlen;
+	do {
+		loopcnt = min_t(unsigned int, LPC_MAX_BURST, cntleft);
+		if (hisilpc_target_out(lpcdev, &iopara, ptaddr, newbuf,
+						loopcnt))
+			break;
+		newbuf += loopcnt;
+		cntleft -= loopcnt;
+	} while (cntleft);
+}
+
+static struct hostio_ops hisi_lpc_ops = {
+	.pfin = hisilpc_comm_in,
+	.pfout = hisilpc_comm_out,
+	.pfins = hisilpc_comm_ins,
+	.pfouts = hisilpc_comm_outs,
+};
+
+/**
+ * hisilpc_probe - the probe callback function for hisi lpc device,
+ *		   will finish all the initialization.
+ * @pdev: the platform device corresponding to hisi lpc
+ *
+ * Returns 0 on success, non-zero on fail.
+ */
+static int hisilpc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct hisilpc_dev *lpcdev;
+	int ret = 0;
+
+	lpcdev = devm_kzalloc(dev, sizeof(struct hisilpc_dev), GFP_KERNEL);
+	if (!lpcdev)
+		return -ENOMEM;
+
+	spin_lock_init(&lpcdev->cycle_lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	lpcdev->membase = devm_ioremap_resource(dev, res);
+	if (IS_ERR(lpcdev->membase)) {
+		dev_err(dev, "remap failed\n");
+		return PTR_ERR(lpcdev->membase);
+	}
+
+	/* register the LPC host PIO resources */
+	{
+		struct logic_pio_hwaddr *range;
+
+		range = devm_kzalloc(dev, sizeof(*range), GFP_KERNEL);
+		if (!range)
+			return -ENOMEM;
+		range->fwnode = dev->fwnode;
+		range->flags = PIO_INDIRECT;
+		range->size = LPC_BUS_IO_SIZE;
+		range->hw_start = LPC_MIN_BUS_RANGE;
+
+		ret = logic_pio_register_range(range);
+		if (ret) {
+			kfree(range);
+			dev_err(dev, "register IO range failed (%d)!\n", ret);
+			return -ret;
+		}
+		lpcdev->io_host = range;
+
+		/*
+		 * It is time to start the children scanning:
+		 * For ACPI children, the corresponding devices had been
+		 * created during the ACPI enumeration.
+		 * The OF scanning must be performed after initialization of
+		 * 'lpcdev' to avoid some children which complete the scanning
+		 * trigger the MMIO accesses which will probably cause a panic.
+		 */
+		ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+		if (ret) {
+			/*
+			 * When LPC probing is not completely successful, set
+			 * 'devpara' as NULL. This will make all the LPC I/O
+			 * return failure directly without any hardware
+			 * operations. It will prevent some peripherals which
+			 * had not finished the initialization to manipulate
+			 * I/O for safety.
+			 */
+			lpcdev->io_host->devpara = NULL;
+			dev_err(dev, "populate children failed(%d)\n", ret);
+			return ret;
+		}
+	}
+	lpcdev->io_host->devpara = lpcdev;
+	lpcdev->io_host->ops = &hisi_lpc_ops;
+
+	dev_info(dev, "registered range[%pa - sz:%pa]\n",
+		 &lpcdev->io_host->io_start,
+		 &lpcdev->io_host->size);
+
+	return ret;
+}
+
+static const struct of_device_id hisilpc_of_match[] = {
+	{ .compatible = "hisilicon,hip06-lpc", },
+	{ .compatible = "hisilicon,hip07-lpc", },
+	{},
+};
+
+static struct platform_driver hisilpc_driver = {
+	.driver = {
+		.name           = "hisi_lpc",
+		.of_match_table = hisilpc_of_match,
+	},
+	.probe = hisilpc_probe,
+};
+
+builtin_platform_driver(hisilpc_driver);