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Subject[RFC v1 4/6] platform: x86: Add generic Intel IPC driver
Date
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Currently intel_scu_ipc.c, intel_pmc_ipc.c and intel_punit_ipc.c
redundantly implements the same IPC features and has lot of code
duplication between them. This driver addresses this issue by grouping
the common IPC functionalities under the same driver.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
arch/x86/include/asm/intel_ipc_dev.h | 148 ++++++++++++
drivers/platform/x86/Kconfig | 8 +
drivers/platform/x86/Makefile | 1 +
drivers/platform/x86/intel_ipc_dev.c | 433 +++++++++++++++++++++++++++++++++++
4 files changed, 590 insertions(+)
create mode 100644 arch/x86/include/asm/intel_ipc_dev.h
create mode 100644 drivers/platform/x86/intel_ipc_dev.c

diff --git a/arch/x86/include/asm/intel_ipc_dev.h b/arch/x86/include/asm/intel_ipc_dev.h
new file mode 100644
index 0000000..29b21fa
--- /dev/null
+++ b/arch/x86/include/asm/intel_ipc_dev.h
@@ -0,0 +1,148 @@
+/*
+ * intel_ipc_dev.h: IPC class device header file
+ *
+ * (C) Copyright 2017 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/device.h>
+
+/* IPC channel type */
+#define IPC_CHANNEL_IA_PMC 0
+#define IPC_CHANNEL_IA_PUNIT 1
+#define IPC_CHANNEL_PMC_PUNIT 2
+#define IPC_CHANNEL_MAX 3
+
+/* IPC return code */
+#define IPC_DEV_ERR_NONE 0
+#define IPC_DEV_ERR_CMD_NOT_SUPPORTED 1
+#define IPC_DEV_ERR_CMD_NOT_SERVICED 2
+#define IPC_DEV_ERR_UNABLE_TO_SERVICE 3
+#define IPC_DEV_ERR_CMD_INVALID 4
+#define IPC_DEV_ERR_CMD_FAILED 5
+#define IPC_DEV_ERR_EMSECURITY 6
+#define IPC_DEV_ERR_UNSIGNEDKERNEL 7
+
+/* IPC mode */
+#define IPC_DEV_MODE_IRQ 0
+#define IPC_DEV_MODE_POLLING 1
+
+/* IPC dev constants */
+#define IPC_DEV_CMD_LOOP_CNT 3000000
+#define IPC_DEV_CMD_TIMEOUT 3 * HZ
+#define IPC_DEV_DATA_BUFFER_SIZE 16
+
+struct intel_ipc_dev;
+
+/**
+ * struct intel_ipc_dev_cfg - IPC device config structure.
+ *
+ * IPC device drivers should provide following config options to
+ * register new IPC device.
+ *
+ * @base: IPC device memory resource start address.
+ * @wrbuf_reg: IPC device data write register address.
+ * @rbuf_reg: IPC device data read register address.
+ * @sptr_reg: IPC device source data pointer register address.
+ * @dptr_reg: IPC device destination data pointer register address.
+ * @status_reg: IPC command status register address.
+ * @cmd_reg: IPC command register address.
+ * @mode: IRQ/POLLING mode.
+ * @irq: IPC device IRQ number.
+ * @irqflags: IPC device IRQ flags.
+ * @chan_type: IPC device channel type(PMC/PUNIT).
+ * @msi: Enable/Disable MSI for IPC commands.
+ *
+ */
+struct intel_ipc_dev_cfg {
+ void __iomem *base;
+ void __iomem *wrbuf_reg;
+ void __iomem *rbuf_reg;
+ void __iomem *sptr_reg;
+ void __iomem *dptr_reg;
+ void __iomem *status_reg;
+ void __iomem *cmd_reg;
+ int mode;
+ int irq;
+ int irqflags;
+ int chan_type;
+ bool use_msi;
+};
+
+/**
+ * struct intel_ipc_dev_ops - IPC device ops structure.
+ *
+ * Call backs for IPC device specific operations.
+ *
+ * @err_code : Status to error code conversion function.
+ * @busy_check : Check for IPC busy status.
+ * @cmd_msi : Enable MSI for IPC commands.
+ *
+ */
+struct intel_ipc_dev_ops {
+ int (*to_err_code)(int status);
+ int (*busy_check)(int status);
+ u32 (*enable_msi)(u32 cmd);
+
+};
+
+/**
+ * struct intel_ipc_dev - Intel IPC device structure.
+ *
+ * Used with devm_intel_ipc_dev_create() to create new IPC device.
+ *
+ * @dev: IPC device object.
+ * @cmd: Current IPC device command.
+ * @cmd_complete: Command completion object.
+ * @lock: Lock to protect IPC device structure.
+ * @ops: IPC device ops pointer.
+ * @cfg: IPC device cfg pointer.
+ *
+ */
+struct intel_ipc_dev {
+ struct device dev;
+ int cmd;
+ struct completion cmd_complete;
+ struct mutex lock;
+ struct intel_ipc_dev_ops *ops;
+ struct intel_ipc_dev_cfg *cfg;
+};
+
+#if IS_ENABLED(CONFIG_INTEL_IPC_DEV)
+
+/* API to create new IPC device */
+struct intel_ipc_dev *devm_intel_ipc_dev_create(struct device *dev,
+ const char *devname, struct intel_ipc_dev_cfg *cfg,
+ struct intel_ipc_dev_ops *ops);
+
+int ipc_dev_simple_cmd(struct intel_ipc_dev *ipc_dev, u32 cmd);
+int ipc_dev_raw_cmd(struct intel_ipc_dev *ipc_dev, u32 cmd, u8 *in,
+ u32 inlen, u32 *out, u32 outlen, u32 dptr, u32 sptr);
+#else
+
+static inline struct intel_ipc_dev *devm_intel_ipc_dev_create(
+ struct device *dev,
+ const char *devname, struct intel_ipc_dev_cfg *cfg,
+ struct intel_ipc_dev_ops *ops)
+{
+ return -EINVAL;
+}
+
+static inline int ipc_dev_simple_cmd(struct intel_ipc_dev *ipc_dev, u32 cmd)
+{
+ return -EINVAL;
+}
+
+static inline int ipc_dev_raw_cmd(struct intel_ipc_dev *ipc_dev, u32 cmd,
+ u8 *in, u32 inlen, u32 *out, u32 outlen, u32 dptr, u32 sptr)
+{
+ return -EINVAL;
+}
+
+#endif
diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index b048607..030eac7 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -1138,6 +1138,14 @@ config SILEAD_DMI
with the OS-image for the device. This option supplies the missing
information. Enable this for x86 tablets with Silead touchscreens.

+config INTEL_IPC_DEV
+ tristate "Intel IPC Device Driver"
+ depends on X86_64
+ ---help---
+ This driver implements core features of Intel IPC device. Devices
+ like PMC, SCU, PUNIT, etc can use interfaces provided by this
+ driver to implement IPC protocol of their respective device.
+
endif # X86_PLATFORM_DEVICES

config PMC_ATOM
diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
index 91cec17..04e11ce 100644
--- a/drivers/platform/x86/Makefile
+++ b/drivers/platform/x86/Makefile
@@ -83,3 +83,4 @@ obj-$(CONFIG_PMC_ATOM) += pmc_atom.o
obj-$(CONFIG_MLX_PLATFORM) += mlx-platform.o
obj-$(CONFIG_MLX_CPLD_PLATFORM) += mlxcpld-hotplug.o
obj-$(CONFIG_INTEL_TURBO_MAX_3) += intel_turbo_max_3.o
+obj-$(CONFIG_INTEL_IPC_DEV) += intel_ipc_dev.o
diff --git a/drivers/platform/x86/intel_ipc_dev.c b/drivers/platform/x86/intel_ipc_dev.c
new file mode 100644
index 0000000..6c86b62
--- /dev/null
+++ b/drivers/platform/x86/intel_ipc_dev.c
@@ -0,0 +1,433 @@
+/*
+ * intel_ipc_dev.c: Intel IPC device class driver
+ *
+ * (C) Copyright 2017 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <asm/intel_ipc_dev.h>
+
+/* mutex to sync different ipc devices in same channel */
+static struct mutex channel_lock[IPC_CHANNEL_MAX];
+
+static void ipc_channel_lock_init(void)
+{
+ int i;
+
+ for (i = 0; i < IPC_CHANNEL_MAX; i++)
+ mutex_init(&channel_lock[i]);
+}
+
+static struct class intel_ipc_class = {
+ .name = "intel_ipc",
+ .owner = THIS_MODULE,
+};
+
+static int __init intel_ipc_init(void)
+{
+ ipc_channel_lock_init();
+ return class_register(&intel_ipc_class);
+}
+
+static void __exit intel_ipc_exit(void)
+{
+ class_unregister(&intel_ipc_class);
+}
+
+static int ipc_dev_lock(struct intel_ipc_dev *ipc_dev)
+{
+ int chan_type = ipc_dev->cfg->chan_type;
+
+ if (!ipc_dev)
+ return -ENODEV;
+
+ if (chan_type > IPC_CHANNEL_MAX)
+ return -EINVAL;
+
+ /* acquire channel lock */
+ mutex_lock(&channel_lock[chan_type]);
+
+ /* acquire IPC device lock */
+ mutex_lock(&ipc_dev->lock);
+
+ return 0;
+}
+
+static int ipc_dev_unlock(struct intel_ipc_dev *ipc_dev)
+{
+ int chan_type = ipc_dev->cfg->chan_type;
+
+ if (!ipc_dev)
+ return -ENODEV;
+
+ if (chan_type > IPC_CHANNEL_MAX)
+ return -EINVAL;
+
+ /* release IPC device lock */
+ mutex_unlock(&ipc_dev->lock);
+
+ /* release channel lock */
+ mutex_unlock(&channel_lock[chan_type]);
+
+ return 0;
+}
+
+
+static const char *ipc_dev_err_string(struct intel_ipc_dev *ipc_dev,
+ int error)
+{
+ switch (error) {
+ case IPC_DEV_ERR_NONE:
+ return "No error";
+ case IPC_DEV_ERR_CMD_NOT_SUPPORTED:
+ return "Command not-supported/Invalid";
+ case IPC_DEV_ERR_CMD_NOT_SERVICED:
+ return "Command not-serviced/Invalid param";
+ case IPC_DEV_ERR_UNABLE_TO_SERVICE:
+ return "Unable-to-service/Cmd-timeout";
+ case IPC_DEV_ERR_CMD_INVALID:
+ return "Command-invalid/Cmd-locked";
+ case IPC_DEV_ERR_CMD_FAILED:
+ return "Command-failed/Invalid-VR-id";
+ case IPC_DEV_ERR_EMSECURITY:
+ return "Invalid Battery/VR-Error";
+ case IPC_DEV_ERR_UNSIGNEDKERNEL:
+ return "Unsigned kernel";
+ default:
+ return "Unknown Command";
+ };
+}
+
+/* Helper function to read IPC device status register */
+static inline u32 ipc_dev_read_status(struct intel_ipc_dev *ipc_dev)
+{
+ return readl(ipc_dev->cfg->status_reg);
+}
+
+/* Helper function to write 32 bits to IPC device data register */
+static inline void ipc_dev_write_datal(struct intel_ipc_dev *ipc_dev,
+ u32 data, u32 offset)
+{
+ writel(data, ipc_dev->cfg->wrbuf_reg + offset);
+}
+
+/* Helper function to read 32 bits from IPC device data register */
+static inline u32 ipc_dev_read_datal(struct intel_ipc_dev *ipc_dev,
+ u32 offset)
+{
+ return readl(ipc_dev->cfg->rbuf_reg + offset);
+}
+
+/* Helper function to send given command to IPC device */
+static inline void ipc_dev_send_cmd(struct intel_ipc_dev *ipc_dev,
+ u32 cmd)
+{
+ ipc_dev->cmd = cmd;
+
+ if (ipc_dev->cfg->mode == IPC_DEV_MODE_IRQ)
+ reinit_completion(&ipc_dev->cmd_complete);
+
+ if (ipc_dev->ops->enable_msi)
+ cmd = ipc_dev->ops->enable_msi(cmd);
+
+ writel(cmd, ipc_dev->cfg->cmd_reg);
+}
+
+static inline int ipc_dev_status_busy(struct intel_ipc_dev *ipc_dev)
+{
+ int status = ipc_dev_read_status(ipc_dev);
+
+ if (ipc_dev->ops->busy_check)
+ return ipc_dev->ops->busy_check(status);
+
+ return 0;
+}
+
+/* Check the status of IPC command and return err code if failed */
+static int ipc_dev_check_status(struct intel_ipc_dev *ipc_dev)
+{
+ int loop_count = IPC_DEV_CMD_LOOP_CNT;
+ int status;
+ int ret = 0;
+
+ if (ipc_dev->cfg->mode == IPC_DEV_MODE_IRQ) {
+ if (!wait_for_completion_timeout(&ipc_dev->cmd_complete,
+ IPC_DEV_CMD_TIMEOUT))
+ ret = -ETIMEDOUT;
+ } else {
+ while (ipc_dev_status_busy(ipc_dev) && --loop_count)
+ udelay(1);
+ if (!loop_count)
+ ret = -ETIMEDOUT;
+ }
+
+ if (ret < 0) {
+ dev_err(&ipc_dev->dev,
+ "IPC timed out, CMD=0x%x\n", ipc_dev->cmd);
+ return ret;
+ }
+
+ status = ipc_dev_read_status(ipc_dev);
+
+ if (ipc_dev->ops->to_err_code)
+ ret = ipc_dev->ops->to_err_code(status);
+
+ if (ret) {
+ dev_err(&ipc_dev->dev,
+ "IPC failed: %s, STS=0x%x, CMD=0x%x\n",
+ ipc_dev_err_string(ipc_dev, ret),
+ status, ipc_dev->cmd);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+/**
+ * ipc_dev_simple_cmd() - Send simple IPC command
+ * @ipc_dev : Reference to ipc device.
+ * @cmd : IPC command code.
+ *
+ * Send a simple IPC command to ipc device.
+ * Use this when don't need to specify input/output data
+ * and source/dest pointers.
+ *
+ * Return: an IPC error code or 0 on success.
+ */
+
+int ipc_dev_simple_cmd(struct intel_ipc_dev *ipc_dev, u32 cmd)
+{
+ int ret;
+
+ ipc_dev_lock(ipc_dev);
+ ipc_dev_send_cmd(ipc_dev, cmd);
+ ret = ipc_dev_check_status(ipc_dev);
+ ipc_dev_unlock(ipc_dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ipc_dev_simple_cmd);
+
+/**
+ * ipc_dev_raw_cmd() - IPC command with data and pointers
+ * @ipc_dev : reference to ipc_dev.
+ * @cmd : IPC command code.
+ * @in : input data of this IPC command.
+ * @inlen : input data length in bytes.
+ * @out : output data of this IPC command.
+ * @outlen : output data length in dwords.
+ * @sptr : data writing to SPTR register. Use 0 if want to skip.
+ * @dptr : data writing to DPTR register. Use 0 if want to skip.
+ *
+ * Send an IPC command to device with input/output data and
+ * source/dest pointers.
+ *
+ * Return: an IPC error code or 0 on success.
+ */
+
+int ipc_dev_raw_cmd(struct intel_ipc_dev *ipc_dev, u32 cmd,
+ u8 *in, u32 inlen, u32 *out,
+ u32 outlen, u32 dptr, u32 sptr)
+{
+ u32 wbuf[4] = { 0 };
+ int ret;
+ int i;
+
+ ipc_dev_lock(ipc_dev);
+
+ memcpy(wbuf, in, inlen);
+
+ /* write if dptr_reg is valid */
+ if (ipc_dev->cfg->dptr_reg)
+ writel(dptr, ipc_dev->cfg->dptr_reg);
+
+ /* write if sptr_reg is valid */
+ if (ipc_dev->cfg->sptr_reg)
+ writel(sptr, ipc_dev->cfg->sptr_reg);
+
+ /* The input data register is 32bit register and inlen
+ * is in Byte */
+ for (i = 0; i < ((inlen + 3) / 4); i++)
+ ipc_dev_write_datal(ipc_dev, wbuf[i], 4 * i);
+
+ ipc_dev_send_cmd(ipc_dev, cmd);
+
+ ret = ipc_dev_check_status(ipc_dev);
+
+ /* The out data register is 32bit register and outlen
+ * is in 32 bit */
+ if (!ret) {
+ for (i = 0; i < outlen; i++)
+ *out++ = ipc_dev_read_datal(ipc_dev, 4 * i);
+ }
+
+ ipc_dev_unlock(ipc_dev);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(ipc_dev_raw_cmd);
+
+/* sysfs option to send simple IPC commands from userspace */
+static ssize_t ipc_dev_cmd_reg_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct intel_ipc_dev *ipc_dev = dev_get_drvdata(dev);
+ u32 cmd;
+ int ret;
+
+ ret = sscanf(buf, "%d", &cmd);
+ if (ret != 1) {
+ dev_err(dev, "Error args\n");
+ return -EINVAL;
+ }
+
+ ret = ipc_dev_simple_cmd(ipc_dev, cmd);
+ if (ret) {
+ dev_err(dev, "command 0x%x error with %d\n", cmd, ret);
+ return ret;
+ }
+ return (ssize_t)count;
+}
+
+static DEVICE_ATTR(send_cmd, S_IWUSR, NULL, ipc_dev_cmd_reg_store);
+
+static struct attribute *ipc_dev_attrs[] = {
+ &dev_attr_send_cmd.attr,
+ NULL
+};
+
+static const struct attribute_group ipc_dev_group = {
+ .attrs = ipc_dev_attrs,
+};
+
+static const struct attribute_group *ipc_dev_groups[] = {
+ &ipc_dev_group,
+ NULL,
+};
+
+/* IPC device IRQ handler */
+static irqreturn_t ipc_dev_irq_handler(int irq, void *dev_id)
+{
+ struct intel_ipc_dev *ipc_dev = (struct intel_ipc_dev *)dev_id;
+
+ complete(&ipc_dev->cmd_complete);
+
+ return IRQ_HANDLED;
+}
+
+static void devm_intel_ipc_dev_release(struct device *dev, void *res)
+{
+ struct intel_ipc_dev *ipc_dev = *(struct intel_ipc_dev **)res;
+
+ if (!ipc_dev)
+ return;
+
+ device_del(&ipc_dev->dev);
+
+ kfree(ipc_dev);
+}
+
+/**
+ * devm_intel_ipc_dev_create() - Create IPC device
+ * @dev : IPC parent device.
+ * @devname : Name of the IPC device.
+ * @cfg : IPC device configuration.
+ * @ops : IPC device ops.
+ *
+ * Resource managed API to create IPC device with
+ * given configuration.
+ *
+ * Return : IPC device pointer or ERR_PTR(error code).
+ */
+struct intel_ipc_dev *devm_intel_ipc_dev_create(struct device *dev,
+ const char *devname,
+ struct intel_ipc_dev_cfg *cfg,
+ struct intel_ipc_dev_ops *ops)
+{
+ struct intel_ipc_dev **ptr, *ipc_dev;
+ int ret;
+
+ if (!dev && !devname && !cfg)
+ return ERR_PTR(-EINVAL);
+
+ ptr = devres_alloc(devm_intel_ipc_dev_release, sizeof(*ptr),
+ GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ ipc_dev = kzalloc(sizeof(*ipc_dev), GFP_KERNEL);
+ if (!ipc_dev) {
+ ret = -ENOMEM;
+ goto err_dev_create;
+ }
+
+ ipc_dev->dev.class = &intel_ipc_class;
+ ipc_dev->dev.parent = dev;
+ ipc_dev->dev.groups = ipc_dev_groups;
+ ipc_dev->cfg = cfg;
+ ipc_dev->ops = ops;
+
+ mutex_init(&ipc_dev->lock);
+ init_completion(&ipc_dev->cmd_complete);
+ dev_set_drvdata(&ipc_dev->dev, ipc_dev);
+ dev_set_name(&ipc_dev->dev, devname);
+ device_initialize(&ipc_dev->dev);
+
+ ret = device_add(&ipc_dev->dev);
+ if (ret < 0) {
+ dev_err(&ipc_dev->dev, "%s device create failed\n",
+ __func__);
+ ret = -ENODEV;
+ goto err_dev_add;
+ }
+
+ if (ipc_dev->cfg->mode == IPC_DEV_MODE_IRQ) {
+ if (devm_request_irq(&ipc_dev->dev,
+ ipc_dev->cfg->irq,
+ ipc_dev_irq_handler,
+ ipc_dev->cfg->irqflags,
+ dev_name(&ipc_dev->dev),
+ ipc_dev)) {
+ dev_err(&ipc_dev->dev,
+ "Failed to request irq\n");
+ goto err_irq_request;
+ }
+ }
+
+ *ptr = ipc_dev;
+
+ devres_add(dev, ptr);
+
+ return ipc_dev;
+
+err_irq_request:
+ device_del(&ipc_dev->dev);
+err_dev_add:
+ kfree(ipc_dev);
+err_dev_create:
+ devres_free(ptr);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(devm_intel_ipc_dev_create);
+
+subsys_initcall(intel_ipc_init);
+module_exit(intel_ipc_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Kuppuswamy Sathyanarayanan<sathyanarayanan.kuppuswamy@linux.intel.com>");
+MODULE_DESCRIPTION("Intel IPC device class driver");
--
2.7.4
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