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Subject[PATCH v17 06/10] HISI LPC: Support the LPC host on Hip06/Hip07 with DT bindings
Date
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.

The driver config is set as a bool instead of a trisate. The reason
here is that, by the very nature of the driver providing a logical
PIO range, it does not make sense to have this driver as a loadable
module. Another more specific reason is that the Huawei D03 board
which includes hip06 SoC requires the LPC bus for UART console, so
should be built in.

Signed-off-by: Zou Rongrong <zourongrong@huawei.com>
Signed-off-by: Zhichang Yuan <yuanzhichang@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Acked-by: Rob Herring <robh@kernel.org> #dts part
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: dann frazier <dann.frazier@canonical.com>
---
.../arm/hisilicon/hisilicon-low-pin-count.txt | 33 ++
drivers/bus/Kconfig | 8 +
drivers/bus/Makefile | 2 +
drivers/bus/hisi_lpc.c | 421 +++++++++++++++++++++
4 files changed, 464 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/hisilicon/hisilicon-low-pin-count.txt
create mode 100644 drivers/bus/hisi_lpc.c

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 769599b..0097317 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 b666c49..b8d9ffb 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -12,6 +12,8 @@ obj-$(CONFIG_BRCMSTB_GISB_ARB) += brcmstb_gisb.o
# DPAA2 fsl-mc bus
obj-$(CONFIG_FSL_MC_BUS) += fsl-mc/

+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..c331609
--- /dev/null
+++ b/drivers/bus/hisi_lpc.c
@@ -0,0 +1,421 @@
+// 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/slab.h>
+
+#define DRV_NAME "hisi-lpc"
+
+/*
+ * 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 hisi_lpc_dev {
+ spinlock_t cycle_lock;
+ void __iomem *membase;
+ struct logic_pio_hwaddr *io_host;
+};
+
+/* The maxIO 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 operation, such as inb. */
+#define LPC_PEROP_WAITCNT 100
+
+static inline int wait_lpc_idle(unsigned char *mbase,
+ unsigned int waitcnt) {
+ do {
+ u32 status;
+
+ 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 inline 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 outputted from caller, maximum is four bytes.
+ * @dwidth: the data width required writing to the target I/O port.
+ *
+ * This function is corresponding 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,
+};
+
+/*
+ * 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;
+
+ ret = logic_pio_register_range(range);
+ if (ret) {
+ dev_err(dev, "register IO range failed (%d)!\n", ret);
+ return ret;
+ }
+ lpcdev->io_host = range;
+
+ /* register the LPC host PIO resources */
+ if (!acpi_device)
+ ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+ if (ret)
+ return ret;
+
+ lpcdev->io_host->hostdata = lpcdev;
+ lpcdev->io_host->ops = &hisi_lpc_ops;
+
+ 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 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,
+ },
+ .probe = hisi_lpc_probe,
+};
+
+builtin_platform_driver(hisi_lpc_driver);
--
1.9.1
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