HID: intel-ish-hid: ipc layer

This layer is responsible for
- Enumerating over PCI bus
- Inform FW about host readiness
- Provide HW interface to transport layer for control and messages
- Interrupt handling and routing

Original-author: Daniel Drubin <daniel.drubin@intel.com>
Reviewed-and-tested-by: Ooi, Joyce <joyce.ooi@intel.com>
Tested-by: Grant Likely <grant.likely@secretlab.ca>
Tested-by: Rann Bar-On <rb6@duke.edu>
Tested-by: Atri Bhattacharya <badshah400@aim.com>
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/intel-ish-hid/Makefile

@@ -10,3 +10,9 @@ intel-ishtp-objs += ishtp/client.o
 intel-ishtp-objs += ishtp/bus.o
 intel-ishtp-objs += ishtp/dma-if.o
 intel-ishtp-objs += ishtp/client-buffers.o
+
+obj-$(CONFIG_INTEL_ISH_HID) += intel-ish-ipc.o
+intel-ish-ipc-objs := ipc/ipc.o
+intel-ish-ipc-objs += ipc/pci-ish.o
+
+ccflags-y += -Idrivers/hid/intel-ish-hid/ishtp

drivers/hid/intel-ish-hid/ipc/hw-ish-regs.h

+/*
+ * ISH registers definitions
+ *
+ * Copyright (c) 2012-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ */
+
+#ifndef _ISHTP_ISH_REGS_H_
+#define _ISHTP_ISH_REGS_H_
+
+
+/*** IPC PCI Offsets and sizes ***/
+/* ISH IPC Base Address */
+#define IPC_REG_BASE		0x0000
+/* Peripheral Interrupt Status Register */
+#define IPC_REG_PISR_CHV_AB      (IPC_REG_BASE + 0x00)
+/* Peripheral Interrupt Mask Register */
+#define IPC_REG_PIMR_CHV_AB      (IPC_REG_BASE + 0x04)
+/*BXT, CHV_K0*/
+/*Peripheral Interrupt Status Register */
+#define IPC_REG_PISR_BXT	 (IPC_REG_BASE + 0x0C)
+/*Peripheral Interrupt Mask Register */
+#define IPC_REG_PIMR_BXT	 (IPC_REG_BASE + 0x08)
+/***********************************/
+/* ISH Host Firmware status Register */
+#define IPC_REG_ISH_HOST_FWSTS	(IPC_REG_BASE + 0x34)
+/* Host Communication Register */
+#define IPC_REG_HOST_COMM	(IPC_REG_BASE + 0x38)
+/* Reset register */
+#define IPC_REG_ISH_RST		(IPC_REG_BASE + 0x44)
+
+/* Inbound doorbell register Host to ISH */
+#define IPC_REG_HOST2ISH_DRBL	(IPC_REG_BASE + 0x48)
+/* Outbound doorbell register ISH to Host */
+#define IPC_REG_ISH2HOST_DRBL	(IPC_REG_BASE + 0x54)
+/* ISH to HOST message registers */
+#define IPC_REG_ISH2HOST_MSG	(IPC_REG_BASE + 0x60)
+/* HOST to ISH message registers */
+#define IPC_REG_HOST2ISH_MSG	(IPC_REG_BASE + 0xE0)
+/* REMAP2 to enable DMA (D3 RCR) */
+#define	IPC_REG_ISH_RMP2	(IPC_REG_BASE + 0x368)
+
+#define	IPC_REG_MAX		(IPC_REG_BASE + 0x400)
+
+/*** register bits - HISR ***/
+/* bit corresponds HOST2ISH interrupt in PISR and PIMR registers */
+#define IPC_INT_HOST2ISH_BIT            (1<<0)
+/***********************************/
+/*CHV_A0, CHV_B0*/
+/* bit corresponds ISH2HOST interrupt in PISR and PIMR registers */
+#define IPC_INT_ISH2HOST_BIT_CHV_AB	(1<<3)
+/*BXT, CHV_K0*/
+/* bit corresponds ISH2HOST interrupt in PISR and PIMR registers */
+#define IPC_INT_ISH2HOST_BIT_BXT	(1<<0)
+/***********************************/
+
+/* bit corresponds ISH2HOST busy clear interrupt in PIMR register */
+#define IPC_INT_ISH2HOST_CLR_MASK_BIT	(1<<11)
+
+/* offset of ISH2HOST busy clear interrupt in IPC_BUSY_CLR register */
+#define IPC_INT_ISH2HOST_CLR_OFFS	(0)
+
+/* bit corresponds ISH2HOST busy clear interrupt in IPC_BUSY_CLR register */
+#define IPC_INT_ISH2HOST_CLR_BIT	(1<<IPC_INT_ISH2HOST_CLR_OFFS)
+
+/* bit corresponds busy bit in doorbell registers */
+#define IPC_DRBL_BUSY_OFFS		(31)
+#define IPC_DRBL_BUSY_BIT		(1<<IPC_DRBL_BUSY_OFFS)
+
+#define	IPC_HOST_OWNS_MSG_OFFS		(30)
+
+/*
+ * A0: bit means that host owns MSGnn registers and is reading them.
+ * ISH FW may not write to them
+ */
+#define	IPC_HOST_OWNS_MSG_BIT		(1<<IPC_HOST_OWNS_MSG_OFFS)
+
+/*
+ * Host status bits (HOSTCOMM)
+ */
+/* bit corresponds host ready bit in Host Status Register (HOST_COMM) */
+#define IPC_HOSTCOMM_READY_OFFS		(7)
+#define IPC_HOSTCOMM_READY_BIT		(1<<IPC_HOSTCOMM_READY_OFFS)
+
+/***********************************/
+/*CHV_A0, CHV_B0*/
+#define	IPC_HOSTCOMM_INT_EN_OFFS_CHV_AB	(31)
+#define	IPC_HOSTCOMM_INT_EN_BIT_CHV_AB		\
+	(1<<IPC_HOSTCOMM_INT_EN_OFFS_CHV_AB)
+/*BXT, CHV_K0*/
+#define IPC_PIMR_INT_EN_OFFS_BXT	(0)
+#define IPC_PIMR_INT_EN_BIT_BXT		(1<<IPC_PIMR_INT_EN_OFFS_BXT)
+
+#define IPC_HOST2ISH_BUSYCLEAR_MASK_OFFS_BXT	(8)
+#define IPC_HOST2ISH_BUSYCLEAR_MASK_BIT		\
+	(1<<IPC_HOST2ISH_BUSYCLEAR_MASK_OFFS_BXT)
+/***********************************/
+/*
+ * both Host and ISH have ILUP at bit 0
+ * bit corresponds host ready bit in both status registers
+ */
+#define IPC_ILUP_OFFS			(0)
+#define IPC_ILUP_BIT			(1<<IPC_ILUP_OFFS)
+
+/*
+ * FW status bits (relevant)
+ */
+#define	IPC_FWSTS_ILUP		0x1
+#define	IPC_FWSTS_ISHTP_UP	(1<<1)
+#define	IPC_FWSTS_DMA0		(1<<16)
+#define	IPC_FWSTS_DMA1		(1<<17)
+#define	IPC_FWSTS_DMA2		(1<<18)
+#define	IPC_FWSTS_DMA3		(1<<19)
+
+#define	IPC_ISH_IN_DMA		\
+	(IPC_FWSTS_DMA0 | IPC_FWSTS_DMA1 | IPC_FWSTS_DMA2 | IPC_FWSTS_DMA3)
+
+/* bit corresponds host ready bit in ISH FW Status Register */
+#define IPC_ISH_ISHTP_READY_OFFS		(1)
+#define IPC_ISH_ISHTP_READY_BIT		(1<<IPC_ISH_ISHTP_READY_OFFS)
+
+#define	IPC_RMP2_DMA_ENABLED	0x1	/* Value to enable DMA, per D3 RCR */
+
+#define IPC_MSG_MAX_SIZE	0x80
+
+
+#define IPC_HEADER_LENGTH_MASK		0x03FF
+#define IPC_HEADER_PROTOCOL_MASK	0x0F
+#define IPC_HEADER_MNG_CMD_MASK		0x0F
+
+#define IPC_HEADER_LENGTH_OFFSET	0
+#define IPC_HEADER_PROTOCOL_OFFSET	10
+#define IPC_HEADER_MNG_CMD_OFFSET	16
+
+#define IPC_HEADER_GET_LENGTH(drbl_reg)		\
+	(((drbl_reg) >> IPC_HEADER_LENGTH_OFFSET)&IPC_HEADER_LENGTH_MASK)
+#define IPC_HEADER_GET_PROTOCOL(drbl_reg)	\
+	(((drbl_reg) >> IPC_HEADER_PROTOCOL_OFFSET)&IPC_HEADER_PROTOCOL_MASK)
+#define IPC_HEADER_GET_MNG_CMD(drbl_reg)	\
+	(((drbl_reg) >> IPC_HEADER_MNG_CMD_OFFSET)&IPC_HEADER_MNG_CMD_MASK)
+
+#define IPC_IS_BUSY(drbl_reg)			\
+	(((drbl_reg)&IPC_DRBL_BUSY_BIT) == ((uint32_t)IPC_DRBL_BUSY_BIT))
+
+/***********************************/
+/*CHV_A0, CHV_B0*/
+#define IPC_INT_FROM_ISH_TO_HOST_CHV_AB(drbl_reg) \
+	(((drbl_reg)&IPC_INT_ISH2HOST_BIT_CHV_AB) == \
+	((u32)IPC_INT_ISH2HOST_BIT_CHV_AB))
+/*BXT, CHV_K0*/
+#define IPC_INT_FROM_ISH_TO_HOST_BXT(drbl_reg) \
+	(((drbl_reg)&IPC_INT_ISH2HOST_BIT_BXT) == \
+	((u32)IPC_INT_ISH2HOST_BIT_BXT))
+/***********************************/
+
+#define IPC_BUILD_HEADER(length, protocol, busy)		\
+	(((busy)<<IPC_DRBL_BUSY_OFFS) |				\
+	((protocol) << IPC_HEADER_PROTOCOL_OFFSET) |		\
+	((length)<<IPC_HEADER_LENGTH_OFFSET))
+
+#define IPC_BUILD_MNG_MSG(cmd, length)				\
+	(((1)<<IPC_DRBL_BUSY_OFFS)|				\
+	((IPC_PROTOCOL_MNG)<<IPC_HEADER_PROTOCOL_OFFSET)|	\
+	((cmd)<<IPC_HEADER_MNG_CMD_OFFSET)|			\
+	 ((length)<<IPC_HEADER_LENGTH_OFFSET))
+
+
+#define IPC_SET_HOST_READY(host_status)		\
+				((host_status) |= (IPC_HOSTCOMM_READY_BIT))
+
+#define IPC_SET_HOST_ILUP(host_status)		\
+				((host_status) |= (IPC_ILUP_BIT))
+
+#define IPC_CLEAR_HOST_READY(host_status)	\
+				((host_status) ^= (IPC_HOSTCOMM_READY_BIT))
+
+#define IPC_CLEAR_HOST_ILUP(host_status)	\
+				((host_status) ^= (IPC_ILUP_BIT))
+
+/* todo - temp until PIMR HW ready */
+#define IPC_HOST_BUSY_READING_OFFS	6
+
+/* bit corresponds host ready bit in Host Status Register (HOST_COMM) */
+#define IPC_HOST_BUSY_READING_BIT	(1<<IPC_HOST_BUSY_READING_OFFS)
+
+#define IPC_SET_HOST_BUSY_READING(host_status)	\
+				((host_status) |= (IPC_HOST_BUSY_READING_BIT))
+
+#define IPC_CLEAR_HOST_BUSY_READING(host_status)\
+				((host_status) ^= (IPC_HOST_BUSY_READING_BIT))
+
+
+#define IPC_IS_ISH_ISHTP_READY(ish_status)	\
+		(((ish_status) & IPC_ISH_ISHTP_READY_BIT) ==	\
+			((uint32_t)IPC_ISH_ISHTP_READY_BIT))
+
+#define IPC_IS_ISH_ILUP(ish_status)		\
+		(((ish_status) & IPC_ILUP_BIT) == ((uint32_t)IPC_ILUP_BIT))
+
+
+#define IPC_PROTOCOL_ISHTP		1
+#define IPC_PROTOCOL_MNG		3
+
+#define MNG_RX_CMPL_ENABLE		0
+#define MNG_RX_CMPL_DISABLE		1
+#define MNG_RX_CMPL_INDICATION		2
+#define MNG_RESET_NOTIFY		3
+#define MNG_RESET_NOTIFY_ACK		4
+#define MNG_SYNC_FW_CLOCK		5
+#define MNG_ILLEGAL_CMD			0xFF
+
+#endif /* _ISHTP_ISH_REGS_H_ */

drivers/hid/intel-ish-hid/ipc/hw-ish.h

+/*
+ * H/W layer of ISHTP provider device (ISH)
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ */
+
+#ifndef _ISHTP_HW_ISH_H_
+#define _ISHTP_HW_ISH_H_
+
+#include <linux/pci.h>
+#include <linux/interrupt.h>
+#include "hw-ish-regs.h"
+#include "ishtp-dev.h"
+
+#define CHV_DEVICE_ID		0x22D8
+#define BXT_Ax_DEVICE_ID	0x0AA2
+#define BXT_Bx_DEVICE_ID	0x1AA2
+#define APL_Ax_DEVICE_ID	0x5AA2
+#define SPT_Ax_DEVICE_ID	0x9D35
+
+#define	REVISION_ID_CHT_A0	0x6
+#define	REVISION_ID_CHT_Ax_SI	0x0
+#define	REVISION_ID_CHT_Bx_SI	0x10
+#define	REVISION_ID_CHT_Kx_SI	0x20
+#define	REVISION_ID_CHT_Dx_SI	0x30
+#define	REVISION_ID_CHT_B0	0xB0
+#define	REVISION_ID_SI_MASK	0x70
+
+struct ipc_rst_payload_type {
+	uint16_t	reset_id;
+	uint16_t	reserved;
+};
+
+struct time_sync_format {
+	uint8_t ts1_source;
+	uint8_t ts2_source;
+	uint16_t reserved;
+} __packed;
+
+struct ipc_time_update_msg {
+	uint64_t primary_host_time;
+	struct time_sync_format sync_info;
+	uint64_t secondary_host_time;
+} __packed;
+
+enum {
+	HOST_UTC_TIME_USEC = 0,
+	HOST_SYSTEM_TIME_USEC = 1
+};
+
+struct ish_hw {
+	void __iomem *mem_addr;
+};
+
+#define to_ish_hw(dev) (struct ish_hw *)((dev)->hw)
+
+irqreturn_t ish_irq_handler(int irq, void *dev_id);
+struct ishtp_device *ish_dev_init(struct pci_dev *pdev);
+int ish_hw_start(struct ishtp_device *dev);
+void ish_device_disable(struct ishtp_device *dev);
+
+#endif /* _ISHTP_HW_ISH_H_ */

drivers/hid/intel-ish-hid/ipc/ipc.c

+/*
+ * H/W layer of ISHTP provider device (ISH)
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/sched.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/jiffies.h>
+#include "client.h"
+#include "hw-ish.h"
+#include "utils.h"
+#include "hbm.h"
+
+/* For FW reset flow */
+static struct work_struct fw_reset_work;
+static struct ishtp_device *ishtp_dev;
+
+/**
+ * ish_reg_read() - Read register
+ * @dev: ISHTP device pointer
+ * @offset: Register offset
+ *
+ * Read 32 bit register at a given offset
+ *
+ * Return: Read register value
+ */
+static inline uint32_t ish_reg_read(const struct ishtp_device *dev,
+	unsigned long offset)
+{
+	struct ish_hw *hw = to_ish_hw(dev);
+
+	return readl(hw->mem_addr + offset);
+}
+
+/**
+ * ish_reg_write() - Write register
+ * @dev: ISHTP device pointer
+ * @offset: Register offset
+ * @value: Value to write
+ *
+ * Writes 32 bit register at a give offset
+ */
+static inline void ish_reg_write(struct ishtp_device *dev,
+				 unsigned long offset,
+				 uint32_t value)
+{
+	struct ish_hw *hw = to_ish_hw(dev);
+
+	writel(value, hw->mem_addr + offset);
+}
+
+/**
+ * _ish_read_fw_sts_reg() - Read FW status register
+ * @dev: ISHTP device pointer
+ *
+ * Read FW status register
+ *
+ * Return: Read register value
+ */
+static inline uint32_t _ish_read_fw_sts_reg(struct ishtp_device *dev)
+{
+	return ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+}
+
+/**
+ * check_generated_interrupt() - Check if ISH interrupt
+ * @dev: ISHTP device pointer
+ *
+ * Check if an interrupt was generated for ISH
+ *
+ * Return: Read true or false
+ */
+static bool check_generated_interrupt(struct ishtp_device *dev)
+{
+	bool interrupt_generated = true;
+	uint32_t pisr_val = 0;
+
+	if (dev->pdev->device == CHV_DEVICE_ID) {
+		pisr_val = ish_reg_read(dev, IPC_REG_PISR_CHV_AB);
+		interrupt_generated =
+			IPC_INT_FROM_ISH_TO_HOST_CHV_AB(pisr_val);
+	} else {
+		pisr_val = ish_reg_read(dev, IPC_REG_PISR_BXT);
+		interrupt_generated = IPC_INT_FROM_ISH_TO_HOST_BXT(pisr_val);
+	}
+
+	return interrupt_generated;
+}
+
+/**
+ * ish_is_input_ready() - Check if FW ready for RX
+ * @dev: ISHTP device pointer
+ *
+ * Check if ISH FW is ready for receiving data
+ *
+ * Return: Read true or false
+ */
+static bool ish_is_input_ready(struct ishtp_device *dev)
+{
+	uint32_t doorbell_val;
+
+	doorbell_val = ish_reg_read(dev, IPC_REG_HOST2ISH_DRBL);
+	return !IPC_IS_BUSY(doorbell_val);
+}
+
+/**
+ * set_host_ready() - Indicate host ready
+ * @dev: ISHTP device pointer
+ *
+ * Set host ready indication to FW
+ */
+static void set_host_ready(struct ishtp_device *dev)
+{
+	if (dev->pdev->device == CHV_DEVICE_ID) {
+		if (dev->pdev->revision == REVISION_ID_CHT_A0 ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Ax_SI)
+			ish_reg_write(dev, IPC_REG_HOST_COMM, 0x81);
+		else if (dev->pdev->revision == REVISION_ID_CHT_B0 ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Bx_SI ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Kx_SI ||
+				(dev->pdev->revision & REVISION_ID_SI_MASK) ==
+				REVISION_ID_CHT_Dx_SI) {
+			uint32_t host_comm_val;
+
+			host_comm_val = ish_reg_read(dev, IPC_REG_HOST_COMM);
+			host_comm_val |= IPC_HOSTCOMM_INT_EN_BIT_CHV_AB | 0x81;
+			ish_reg_write(dev, IPC_REG_HOST_COMM, host_comm_val);
+		}
+	} else {
+			uint32_t host_pimr_val;
+
+			host_pimr_val = ish_reg_read(dev, IPC_REG_PIMR_BXT);
+			host_pimr_val |= IPC_PIMR_INT_EN_BIT_BXT;
+			/*
+			 * disable interrupt generated instead of
+			 * RX_complete_msg
+			 */
+			host_pimr_val &= ~IPC_HOST2ISH_BUSYCLEAR_MASK_BIT;
+
+			ish_reg_write(dev, IPC_REG_PIMR_BXT, host_pimr_val);
+	}
+}
+
+/**
+ * ishtp_fw_is_ready() - Check if FW ready
+ * @dev: ISHTP device pointer
+ *
+ * Check if ISH FW is ready
+ *
+ * Return: Read true or false
+ */
+static bool ishtp_fw_is_ready(struct ishtp_device *dev)
+{
+	uint32_t ish_status = _ish_read_fw_sts_reg(dev);
+
+	return IPC_IS_ISH_ILUP(ish_status) &&
+		IPC_IS_ISH_ISHTP_READY(ish_status);
+}
+
+/**
+ * ish_set_host_rdy() - Indicate host ready
+ * @dev: ISHTP device pointer
+ *
+ * Set host ready indication to FW
+ */
+static void ish_set_host_rdy(struct ishtp_device *dev)
+{
+	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
+
+	IPC_SET_HOST_READY(host_status);
+	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
+}
+
+/**
+ * ish_clr_host_rdy() - Indicate host not ready
+ * @dev: ISHTP device pointer
+ *
+ * Send host not ready indication to FW
+ */
+static void ish_clr_host_rdy(struct ishtp_device *dev)
+{
+	uint32_t host_status = ish_reg_read(dev, IPC_REG_HOST_COMM);
+
+	IPC_CLEAR_HOST_READY(host_status);
+	ish_reg_write(dev, IPC_REG_HOST_COMM, host_status);
+}
+
+/**
+ * _ishtp_read_hdr() - Read message header
+ * @dev: ISHTP device pointer
+ *
+ * Read header of 32bit length
+ *
+ * Return: Read register value
+ */
+static uint32_t _ishtp_read_hdr(const struct ishtp_device *dev)
+{
+	return ish_reg_read(dev, IPC_REG_ISH2HOST_MSG);
+}
+
+/**
+ * _ishtp_read - Read message
+ * @dev: ISHTP device pointer
+ * @buffer: message buffer
+ * @buffer_length: length of message buffer
+ *
+ * Read message from FW
+ *
+ * Return: Always 0
+ */
+static int _ishtp_read(struct ishtp_device *dev, unsigned char *buffer,
+	unsigned long buffer_length)
+{
+	uint32_t	i;
+	uint32_t	*r_buf = (uint32_t *)buffer;
+	uint32_t	msg_offs;
+
+	msg_offs = IPC_REG_ISH2HOST_MSG + sizeof(struct ishtp_msg_hdr);
+	for (i = 0; i < buffer_length; i += sizeof(uint32_t))
+		*r_buf++ = ish_reg_read(dev, msg_offs + i);
+
+	return 0;
+}
+
+/**
+ * write_ipc_from_queue() - try to write ipc msg from Tx queue to device
+ * @dev: ishtp device pointer
+ *
+ * Check if DRBL is cleared. if it is - write the first IPC msg,  then call
+ * the callback function (unless it's NULL)
+ *
+ * Return: 0 for success else failure code
+ */
+static int write_ipc_from_queue(struct ishtp_device *dev)
+{
+	struct wr_msg_ctl_info	*ipc_link;
+	unsigned long	length;
+	unsigned long	rem;
+	unsigned long	flags;
+	uint32_t	doorbell_val;
+	uint32_t	*r_buf;
+	uint32_t	reg_addr;
+	int	i;
+	void	(*ipc_send_compl)(void *);
+	void	*ipc_send_compl_prm;
+	static int	out_ipc_locked;
+	unsigned long	out_ipc_flags;
+
+	if (dev->dev_state == ISHTP_DEV_DISABLED)
+		return	-EINVAL;
+
+	spin_lock_irqsave(&dev->out_ipc_spinlock, out_ipc_flags);
+	if (out_ipc_locked) {
+		spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
+		return -EBUSY;
+	}
+	out_ipc_locked = 1;
+	if (!ish_is_input_ready(dev)) {
+		out_ipc_locked = 0;
+		spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
+		return -EBUSY;
+	}
+	spin_unlock_irqrestore(&dev->out_ipc_spinlock, out_ipc_flags);
+
+	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
+	/*
+	 * if tx send list is empty - return 0;
+	 * may happen, as RX_COMPLETE handler doesn't check list emptiness.
+	 */
+	if (list_empty(&dev->wr_processing_list_head.link)) {
+		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+		out_ipc_locked = 0;
+		return	0;
+	}
+
+	ipc_link = list_entry(dev->wr_processing_list_head.link.next,
+			      struct wr_msg_ctl_info, link);
+	/* first 4 bytes of the data is the doorbell value (IPC header) */
+	length = ipc_link->length - sizeof(uint32_t);
+	doorbell_val = *(uint32_t *)ipc_link->inline_data;
+	r_buf = (uint32_t *)(ipc_link->inline_data + sizeof(uint32_t));
+
+	/* If sending MNG_SYNC_FW_CLOCK, update clock again */
+	if (IPC_HEADER_GET_PROTOCOL(doorbell_val) == IPC_PROTOCOL_MNG &&
+		IPC_HEADER_GET_MNG_CMD(doorbell_val) == MNG_SYNC_FW_CLOCK) {
+		struct timespec ts_system;
+		struct timeval tv_utc;
+		uint64_t        usec_system, usec_utc;
+		struct ipc_time_update_msg time_update;
+		struct time_sync_format ts_format;
+
+		get_monotonic_boottime(&ts_system);
+		do_gettimeofday(&tv_utc);
+		usec_system = (timespec_to_ns(&ts_system)) / NSEC_PER_USEC;
+		usec_utc = (uint64_t)tv_utc.tv_sec * 1000000 +
+						((uint32_t)tv_utc.tv_usec);
+		ts_format.ts1_source = HOST_SYSTEM_TIME_USEC;
+		ts_format.ts2_source = HOST_UTC_TIME_USEC;
+
+		time_update.primary_host_time = usec_system;
+		time_update.secondary_host_time = usec_utc;
+		time_update.sync_info = ts_format;
+
+		memcpy(r_buf, &time_update,
+		       sizeof(struct ipc_time_update_msg));
+	}
+
+	for (i = 0, reg_addr = IPC_REG_HOST2ISH_MSG; i < length >> 2; i++,
+			reg_addr += 4)
+		ish_reg_write(dev, reg_addr, r_buf[i]);
+
+	rem = length & 0x3;
+	if (rem > 0) {
+		uint32_t reg = 0;
+
+		memcpy(&reg, &r_buf[length >> 2], rem);
+		ish_reg_write(dev, reg_addr, reg);
+	}
+	/* Flush writes to msg registers and doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	/* Update IPC counters */
+	++dev->ipc_tx_cnt;
+	dev->ipc_tx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
+
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, doorbell_val);
+	out_ipc_locked = 0;
+
+	ipc_send_compl = ipc_link->ipc_send_compl;
+	ipc_send_compl_prm = ipc_link->ipc_send_compl_prm;
+	list_del_init(&ipc_link->link);
+	list_add_tail(&ipc_link->link, &dev->wr_free_list_head.link);
+	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+
+	/*
+	 * callback will be called out of spinlock,
+	 * after ipc_link returned to free list
+	 */
+	if (ipc_send_compl)
+		ipc_send_compl(ipc_send_compl_prm);
+
+	return 0;
+}
+
+/**
+ * write_ipc_to_queue() - write ipc msg to Tx queue
+ * @dev: ishtp device instance
+ * @ipc_send_compl: Send complete callback
+ * @ipc_send_compl_prm:	Parameter to send in complete callback
+ * @msg: Pointer to message
+ * @length: Length of message
+ *
+ * Recived msg with IPC (and upper protocol) header  and add it to the device
+ *  Tx-to-write list then try to send the first IPC waiting msg
+ *  (if DRBL is cleared)
+ * This function returns negative value for failure (means free list
+ *  is empty, or msg too long) and 0 for success.
+ *
+ * Return: 0 for success else failure code
+ */
+static int write_ipc_to_queue(struct ishtp_device *dev,
+	void (*ipc_send_compl)(void *), void *ipc_send_compl_prm,
+	unsigned char *msg, int length)
+{
+	struct wr_msg_ctl_info *ipc_link;
+	unsigned long	flags;
+
+	if (length > IPC_FULL_MSG_SIZE)
+		return -EMSGSIZE;
+
+	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
+	if (list_empty(&dev->wr_free_list_head.link)) {
+		spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+		return -ENOMEM;
+	}
+	ipc_link = list_entry(dev->wr_free_list_head.link.next,
+		struct wr_msg_ctl_info, link);
+	list_del_init(&ipc_link->link);
+
+	ipc_link->ipc_send_compl = ipc_send_compl;
+	ipc_link->ipc_send_compl_prm = ipc_send_compl_prm;
+	ipc_link->length = length;
+	memcpy(ipc_link->inline_data, msg, length);
+
+	list_add_tail(&ipc_link->link, &dev->wr_processing_list_head.link);
+	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+
+	write_ipc_from_queue(dev);
+
+	return 0;
+}
+
+/**
+ * ipc_send_mng_msg() - Send management message
+ * @dev: ishtp device instance
+ * @msg_code: Message code
+ * @msg: Pointer to message
+ * @size: Length of message
+ *
+ * Send management message to FW
+ *
+ * Return: 0 for success else failure code
+ */
+static int ipc_send_mng_msg(struct ishtp_device *dev, uint32_t msg_code,
+	void *msg, size_t size)
+{
+	unsigned char	ipc_msg[IPC_FULL_MSG_SIZE];
+	uint32_t	drbl_val = IPC_BUILD_MNG_MSG(msg_code, size);
+
+	memcpy(ipc_msg, &drbl_val, sizeof(uint32_t));
+	memcpy(ipc_msg + sizeof(uint32_t), msg, size);
+	return	write_ipc_to_queue(dev, NULL, NULL, ipc_msg,
+		sizeof(uint32_t) + size);
+}
+
+/**
+ * ish_fw_reset_handler() - FW reset handler
+ * @dev: ishtp device pointer
+ *
+ * Handle FW reset
+ *
+ * Return: 0 for success else failure code
+ */
+static int ish_fw_reset_handler(struct ishtp_device *dev)
+{
+	uint32_t	reset_id;
+	unsigned long	flags;
+	struct wr_msg_ctl_info *processing, *next;
+
+	/* Read reset ID */
+	reset_id = ish_reg_read(dev, IPC_REG_ISH2HOST_MSG) & 0xFFFF;
+
+	/* Clear IPC output queue */
+	spin_lock_irqsave(&dev->wr_processing_spinlock, flags);
+	list_for_each_entry_safe(processing, next,
+			&dev->wr_processing_list_head.link, link) {
+		list_del(&processing->link);
+		list_add_tail(&processing->link, &dev->wr_free_list_head.link);
+	}
+	spin_unlock_irqrestore(&dev->wr_processing_spinlock, flags);
+
+	/* ISHTP notification in IPC_RESET */
+	ishtp_reset_handler(dev);
+
+	if (!ish_is_input_ready(dev))
+		timed_wait_for_timeout(WAIT_FOR_SEND_SLICE,
+			ish_is_input_ready(dev), (2 * HZ));
+
+	/* ISH FW is dead */
+	if (!ish_is_input_ready(dev))
+		return	-EPIPE;
+	/*
+	 * Set HOST2ISH.ILUP. Apparently we need this BEFORE sending
+	 * RESET_NOTIFY_ACK - FW will be checking for it
+	 */
+	ish_set_host_rdy(dev);
+	/* Send RESET_NOTIFY_ACK (with reset_id) */
+	ipc_send_mng_msg(dev, MNG_RESET_NOTIFY_ACK, &reset_id,
+			 sizeof(uint32_t));
+
+	/* Wait for ISH FW'es ILUP and ISHTP_READY */
+	timed_wait_for_timeout(WAIT_FOR_SEND_SLICE, ishtp_fw_is_ready(dev),
+		(2 * HZ));
+	if (!ishtp_fw_is_ready(dev)) {
+		/* ISH FW is dead */
+		uint32_t	ish_status;
+
+		ish_status = _ish_read_fw_sts_reg(dev);
+		dev_err(dev->devc,
+			"[ishtp-ish]: completed reset, ISH is dead (FWSTS = %08X)\n",
+			ish_status);
+		return -ENODEV;
+	}
+	return	0;
+}
+
+/**
+ * ish_fw_reset_work_fn() - FW reset worker function
+ * @unused: not used
+ *
+ * Call ish_fw_reset_handler to complete FW reset
+ */
+static void fw_reset_work_fn(struct work_struct *unused)
+{
+	int	rv;
+
+	rv = ish_fw_reset_handler(ishtp_dev);
+	if (!rv) {
+		/* ISH is ILUP & ISHTP-ready. Restart ISHTP */
+		schedule_timeout(HZ / 3);
+		ishtp_dev->recvd_hw_ready = 1;
+		wake_up_interruptible(&ishtp_dev->wait_hw_ready);
+
+		/* ISHTP notification in IPC_RESET sequence completion */
+		ishtp_reset_compl_handler(ishtp_dev);
+	} else
+		dev_err(ishtp_dev->devc, "[ishtp-ish]: FW reset failed (%d)\n",
+			rv);
+}
+
+/**
+ * _ish_sync_fw_clock() -Sync FW clock with the OS clock
+ * @dev: ishtp device pointer
+ *
+ * Sync FW and OS time
+ */
+static void _ish_sync_fw_clock(struct ishtp_device *dev)
+{
+	static unsigned long	prev_sync;
+	struct timespec	ts;
+	uint64_t	usec;
+
+	if (prev_sync && jiffies - prev_sync < 20 * HZ)
+		return;
+
+	prev_sync = jiffies;
+	get_monotonic_boottime(&ts);
+	usec = (timespec_to_ns(&ts)) / NSEC_PER_USEC;
+	ipc_send_mng_msg(dev, MNG_SYNC_FW_CLOCK, &usec, sizeof(uint64_t));
+}
+
+/**
+ * recv_ipc() - Receive and process IPC management messages
+ * @dev: ishtp device instance
+ * @doorbell_val: doorbell value
+ *
+ * This function runs in ISR context.
+ * NOTE: Any other mng command than reset_notify and reset_notify_ack
+ * won't wake BH handler
+ */
+static void	recv_ipc(struct ishtp_device *dev, uint32_t doorbell_val)
+{
+	uint32_t	mng_cmd;
+
+	mng_cmd = IPC_HEADER_GET_MNG_CMD(doorbell_val);
+
+	switch (mng_cmd) {
+	default:
+		break;
+
+	case MNG_RX_CMPL_INDICATION:
+		if (dev->suspend_flag) {
+			dev->suspend_flag = 0;
+			wake_up_interruptible(&dev->suspend_wait);
+		}
+		if (dev->resume_flag) {
+			dev->resume_flag = 0;
+			wake_up_interruptible(&dev->resume_wait);
+		}
+
+		write_ipc_from_queue(dev);
+		break;
+
+	case MNG_RESET_NOTIFY:
+		if (!ishtp_dev) {
+			ishtp_dev = dev;
+			INIT_WORK(&fw_reset_work, fw_reset_work_fn);
+		}
+		schedule_work(&fw_reset_work);
+		break;
+
+	case MNG_RESET_NOTIFY_ACK:
+		dev->recvd_hw_ready = 1;
+		wake_up_interruptible(&dev->wait_hw_ready);
+		break;
+	}
+}
+
+/**
+ * ish_irq_handler() - ISH IRQ handler
+ * @irq: irq number
+ * @dev_id: ishtp device pointer
+ *
+ * ISH IRQ handler. If interrupt is generated and is for ISH it will process
+ * the interrupt.
+ */
+irqreturn_t ish_irq_handler(int irq, void *dev_id)
+{
+	struct ishtp_device	*dev = dev_id;
+	uint32_t	doorbell_val;
+	bool	interrupt_generated;
+
+	/* Check that it's interrupt from ISH (may be shared) */
+	interrupt_generated = check_generated_interrupt(dev);
+
+	if (!interrupt_generated)
+		return IRQ_NONE;
+
+	doorbell_val = ish_reg_read(dev, IPC_REG_ISH2HOST_DRBL);
+	if (!IPC_IS_BUSY(doorbell_val))
+		return IRQ_HANDLED;
+
+	if (dev->dev_state == ISHTP_DEV_DISABLED)
+		return	IRQ_HANDLED;
+
+	/* Sanity check: IPC dgram length in header */
+	if (IPC_HEADER_GET_LENGTH(doorbell_val) > IPC_PAYLOAD_SIZE) {
+		dev_err(dev->devc,
+			"IPC hdr - bad length: %u; dropped\n",
+			(unsigned int)IPC_HEADER_GET_LENGTH(doorbell_val));
+		goto	eoi;
+	}
+
+	switch (IPC_HEADER_GET_PROTOCOL(doorbell_val)) {
+	default:
+		break;
+	case IPC_PROTOCOL_MNG:
+		recv_ipc(dev, doorbell_val);
+		break;
+	case IPC_PROTOCOL_ISHTP:
+		ishtp_recv(dev);
+		break;
+	}
+
+eoi:
+	/* Update IPC counters */
+	++dev->ipc_rx_cnt;
+	dev->ipc_rx_bytes_cnt += IPC_HEADER_GET_LENGTH(doorbell_val);
+
+	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
+	/* Flush write to doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	return	IRQ_HANDLED;
+}
+
+/**
+ * _ish_hw_reset() - HW reset
+ * @dev: ishtp device pointer
+ *
+ * Reset ISH HW to recover if any error
+ *
+ * Return: 0 for success else error fault code
+ */
+static int _ish_hw_reset(struct ishtp_device *dev)
+{
+	struct pci_dev *pdev = dev->pdev;
+	int	rv;
+	unsigned int	dma_delay;
+	uint16_t csr;
+
+	if (!pdev)
+		return	-ENODEV;
+
+	rv = pci_reset_function(pdev);
+	if (!rv)
+		dev->dev_state = ISHTP_DEV_RESETTING;
+
+	if (!pdev->pm_cap) {
+		dev_err(&pdev->dev, "Can't reset - no PM caps\n");
+		return	-EINVAL;
+	}
+
+	/* Now trigger reset to FW */
+	ish_reg_write(dev, IPC_REG_ISH_RMP2, 0);
+
+	for (dma_delay = 0; dma_delay < MAX_DMA_DELAY &&
+		_ish_read_fw_sts_reg(dev) & (IPC_ISH_IN_DMA);
+		dma_delay += 5)
+		mdelay(5);
+
+	if (dma_delay >= MAX_DMA_DELAY) {
+		dev_err(&pdev->dev,
+			"Can't reset - stuck with DMA in-progress\n");
+		return	-EBUSY;
+	}
+
+	pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &csr);
+
+	csr &= ~PCI_PM_CTRL_STATE_MASK;
+	csr |= PCI_D3hot;
+	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
+
+	mdelay(pdev->d3_delay);
+
+	csr &= ~PCI_PM_CTRL_STATE_MASK;
+	csr |= PCI_D0;
+	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
+
+	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
+
+	/*
+	 * Send 0 IPC message so that ISH FW wakes up if it was already
+	 * asleep
+	 */
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
+
+	/* Flush writes to doorbell and REMAP2 */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	return	0;
+}
+
+/**
+ * _ish_ipc_reset() - IPC reset
+ * @dev: ishtp device pointer
+ *
+ * Resets host and fw IPC and upper layers
+ *
+ * Return: 0 for success else error fault code
+ */
+static int _ish_ipc_reset(struct ishtp_device *dev)
+{
+	struct ipc_rst_payload_type ipc_mng_msg;
+	int	rv = 0;
+
+	ipc_mng_msg.reset_id = 1;
+	ipc_mng_msg.reserved = 0;
+
+	set_host_ready(dev);
+
+	/* Clear the incoming doorbell */
+	ish_reg_write(dev, IPC_REG_ISH2HOST_DRBL, 0);
+	/* Flush write to doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	dev->recvd_hw_ready = 0;
+
+	/* send message */
+	rv = ipc_send_mng_msg(dev, MNG_RESET_NOTIFY, &ipc_mng_msg,
+		sizeof(struct ipc_rst_payload_type));
+	if (rv) {
+		dev_err(dev->devc, "Failed to send IPC MNG_RESET_NOTIFY\n");
+		return	rv;
+	}
+
+	wait_event_interruptible_timeout(dev->wait_hw_ready,
+					 dev->recvd_hw_ready, 2 * HZ);
+	if (!dev->recvd_hw_ready) {
+		dev_err(dev->devc, "Timed out waiting for HW ready\n");
+		rv = -ENODEV;
+	}
+
+	return rv;
+}
+
+/**
+ * ish_hw_start() -Start ISH HW
+ * @dev: ishtp device pointer
+ *
+ * Set host to ready state and wait for FW reset
+ *
+ * Return: 0 for success else error fault code
+ */
+int ish_hw_start(struct ishtp_device *dev)
+{
+	ish_set_host_rdy(dev);
+	/* After that we can enable ISH DMA operation */
+	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
+
+	/*
+	 * Send 0 IPC message so that ISH FW wakes up if it was already
+	 * asleep
+	 */
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
+	/* Flush write to doorbell */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+
+	set_host_ready(dev);
+
+	/* wait for FW-initiated reset flow */
+	if (!dev->recvd_hw_ready)
+		wait_event_interruptible_timeout(dev->wait_hw_ready,
+						 dev->recvd_hw_ready,
+						 10 * HZ);
+
+	if (!dev->recvd_hw_ready) {
+		dev_err(dev->devc,
+			"[ishtp-ish]: Timed out waiting for FW-initiated reset\n");
+		return	-ENODEV;
+	}
+
+	return 0;
+}
+
+/**
+ * ish_ipc_get_header() -Get doorbell value
+ * @dev: ishtp device pointer
+ * @length: length of message
+ * @busy: busy status
+ *
+ * Get door bell value from message header
+ *
+ * Return: door bell value
+ */
+static uint32_t ish_ipc_get_header(struct ishtp_device *dev, int length,
+				   int busy)
+{
+	uint32_t drbl_val;
+
+	drbl_val = IPC_BUILD_HEADER(length, IPC_PROTOCOL_ISHTP, busy);
+
+	return drbl_val;
+}
+
+static const struct ishtp_hw_ops ish_hw_ops = {
+	.hw_reset = _ish_hw_reset,
+	.ipc_reset = _ish_ipc_reset,
+	.ipc_get_header = ish_ipc_get_header,
+	.ishtp_read = _ishtp_read,
+	.write = write_ipc_to_queue,
+	.get_fw_status = _ish_read_fw_sts_reg,
+	.sync_fw_clock = _ish_sync_fw_clock,
+	.ishtp_read_hdr = _ishtp_read_hdr
+};
+
+/**
+ * ish_dev_init() -Initialize ISH devoce
+ * @pdev: PCI device
+ *
+ * Allocate ISHTP device and initialize IPC processing
+ *
+ * Return: ISHTP device instance on success else NULL
+ */
+struct ishtp_device *ish_dev_init(struct pci_dev *pdev)
+{
+	struct ishtp_device *dev;
+	int	i;
+
+	dev = kzalloc(sizeof(struct ishtp_device) + sizeof(struct ish_hw),
+		GFP_KERNEL);
+	if (!dev)
+		return NULL;
+
+	ishtp_device_init(dev);
+
+	init_waitqueue_head(&dev->wait_hw_ready);
+
+	spin_lock_init(&dev->wr_processing_spinlock);
+	spin_lock_init(&dev->out_ipc_spinlock);
+
+	/* Init IPC processing and free lists */
+	INIT_LIST_HEAD(&dev->wr_processing_list_head.link);
+	INIT_LIST_HEAD(&dev->wr_free_list_head.link);
+	for (i = 0; i < IPC_TX_FIFO_SIZE; ++i) {
+		struct wr_msg_ctl_info	*tx_buf;
+
+		tx_buf = kzalloc(sizeof(struct wr_msg_ctl_info), GFP_KERNEL);
+		if (!tx_buf) {
+			/*
+			 * IPC buffers may be limited or not available
+			 * at all - although this shouldn't happen
+			 */
+			dev_err(dev->devc,
+				"[ishtp-ish]: failure in Tx FIFO allocations (%d)\n",
+				i);
+			break;
+		}
+		list_add_tail(&tx_buf->link, &dev->wr_free_list_head.link);
+	}
+
+	dev->ops = &ish_hw_ops;
+	dev->devc = &pdev->dev;
+	dev->mtu = IPC_PAYLOAD_SIZE - sizeof(struct ishtp_msg_hdr);
+	return dev;
+}
+
+/**
+ * ish_device_disable() - Disable ISH device
+ * @dev: ISHTP device pointer
+ *
+ * Disable ISH by clearing host ready to inform firmware.
+ */
+void	ish_device_disable(struct ishtp_device *dev)
+{
+	dev->dev_state = ISHTP_DEV_DISABLED;
+	ish_clr_host_rdy(dev);
+}

drivers/hid/intel-ish-hid/ipc/pci-ish.c

+/*
+ * PCI glue for ISHTP provider device (ISH) driver
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/module.h>
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/miscdevice.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/intel_ish.h>
+#include "ishtp-dev.h"
+#include "hw-ish.h"
+
+static const struct pci_device_id ish_pci_tbl[] = {
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, CHV_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Ax_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, BXT_Bx_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, APL_Ax_DEVICE_ID)},
+	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, SPT_Ax_DEVICE_ID)},
+	{0, }
+};
+MODULE_DEVICE_TABLE(pci, ish_pci_tbl);
+
+/**
+ * ish_event_tracer() - Callback function to dump trace messages
+ * @dev:	ishtp device
+ * @format:	printf style format
+ *
+ * Callback to direct log messages to Linux trace buffers
+ */
+static void ish_event_tracer(struct ishtp_device *dev, char *format, ...)
+{
+	if (trace_ishtp_dump_enabled()) {
+		va_list args;
+		char tmp_buf[100];
+
+		va_start(args, format);
+		vsnprintf(tmp_buf, sizeof(tmp_buf), format, args);
+		va_end(args);
+
+		trace_ishtp_dump(tmp_buf);
+	}
+}
+
+/**
+ * ish_init() - Init function
+ * @dev:	ishtp device
+ *
+ * This function initialize wait queues for suspend/resume and call
+ * calls hadware initialization function. This will initiate
+ * startup sequence
+ *
+ * Return: 0 for success or error code for failure
+ */
+static int ish_init(struct ishtp_device *dev)
+{
+	int ret;
+
+	/* Set the state of ISH HW to start */
+	ret = ish_hw_start(dev);
+	if (ret) {
+		dev_err(dev->devc, "ISH: hw start failed.\n");
+		return ret;
+	}
+
+	/* Start the inter process communication to ISH processor */
+	ret = ishtp_start(dev);
+	if (ret) {
+		dev_err(dev->devc, "ISHTP: Protocol init failed.\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * ish_probe() - PCI driver probe callback
+ * @pdev:	pci device
+ * @ent:	pci device id
+ *
+ * Initialize PCI function, setup interrupt and call for ISH initialization
+ *
+ * Return: 0 for success or error code for failure
+ */
+static int ish_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
+{
+	struct ishtp_device *dev;
+	struct ish_hw *hw;
+	int	ret;
+
+	/* enable pci dev */
+	ret = pci_enable_device(pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: Failed to enable PCI device\n");
+		return ret;
+	}
+
+	/* set PCI host mastering */
+	pci_set_master(pdev);
+
+	/* pci request regions for ISH driver */
+	ret = pci_request_regions(pdev, KBUILD_MODNAME);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: Failed to get PCI regions\n");
+		goto disable_device;
+	}
+
+	/* allocates and initializes the ISH dev structure */
+	dev = ish_dev_init(pdev);
+	if (!dev) {
+		ret = -ENOMEM;
+		goto release_regions;
+	}
+	hw = to_ish_hw(dev);
+	dev->print_log = ish_event_tracer;
+
+	/* mapping IO device memory */
+	hw->mem_addr = pci_iomap(pdev, 0, 0);
+	if (!hw->mem_addr) {
+		dev_err(&pdev->dev, "ISH: mapping I/O range failure\n");
+		ret = -ENOMEM;
+		goto free_device;
+	}
+
+	dev->pdev = pdev;
+
+	pdev->dev_flags |= PCI_DEV_FLAGS_NO_D3;
+
+	/* request and enable interrupt */
+	ret = request_irq(pdev->irq, ish_irq_handler, IRQF_NO_SUSPEND,
+			  KBUILD_MODNAME, dev);
+	if (ret) {
+		dev_err(&pdev->dev, "ISH: request IRQ failure (%d)\n",
+			pdev->irq);
+		goto free_device;
+	}
+
+	dev_set_drvdata(dev->devc, dev);
+
+	init_waitqueue_head(&dev->suspend_wait);
+	init_waitqueue_head(&dev->resume_wait);
+
+	ret = ish_init(dev);
+	if (ret)
+		goto free_irq;
+
+	return 0;
+
+free_irq:
+	free_irq(pdev->irq, dev);
+free_device:
+	pci_iounmap(pdev, hw->mem_addr);
+	kfree(dev);
+release_regions:
+	pci_release_regions(pdev);
+disable_device:
+	pci_clear_master(pdev);
+	pci_disable_device(pdev);
+	dev_err(&pdev->dev, "ISH: PCI driver initialization failed.\n");
+
+	return ret;
+}
+
+/**
+ * ish_remove() - PCI driver remove callback
+ * @pdev:	pci device
+ *
+ * This function does cleanup of ISH on pci remove callback
+ */
+static void ish_remove(struct pci_dev *pdev)
+{
+	struct ishtp_device *ishtp_dev = pci_get_drvdata(pdev);
+	struct ish_hw *hw = to_ish_hw(ishtp_dev);
+
+	ishtp_bus_remove_all_clients(ishtp_dev, false);
+	ish_device_disable(ishtp_dev);
+
+	free_irq(pdev->irq, ishtp_dev);
+	pci_iounmap(pdev, hw->mem_addr);
+	pci_release_regions(pdev);
+	pci_clear_master(pdev);
+	pci_disable_device(pdev);
+	kfree(ishtp_dev);
+}
+
+static struct device *ish_resume_device;
+
+/**
+ * ish_resume_handler() - Work function to complete resume
+ * @work:	work struct
+ *
+ * The resume work function to complete resume function asynchronously.
+ * There are two types of platforms, one where ISH is not powered off,
+ * in that case a simple resume message is enough, others we need
+ * a reset sequence.
+ */
+static void ish_resume_handler(struct work_struct *work)
+{
+	struct pci_dev *pdev = to_pci_dev(ish_resume_device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+	int ret;
+
+	ishtp_send_resume(dev);
+
+	/* 50 ms to get resume response */
+	if (dev->resume_flag)
+		ret = wait_event_interruptible_timeout(dev->resume_wait,
+						       !dev->resume_flag,
+						       msecs_to_jiffies(50));
+
+	/*
+	 * If no resume response. This platform  is not S0ix compatible
+	 * So on resume full reboot of ISH processor will happen, so
+	 * need to go through init sequence again
+	 */
+	if (dev->resume_flag)
+		ish_init(dev);
+}
+
+/**
+ * ish_suspend() - ISH suspend callback
+ * @device:	device pointer
+ *
+ * ISH suspend callback
+ *
+ * Return: 0 to the pm core
+ */
+static int ish_suspend(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+
+	enable_irq_wake(pdev->irq);
+	/*
+	 * If previous suspend hasn't been asnwered then ISH is likely dead,
+	 * don't attempt nested notification
+	 */
+	if (dev->suspend_flag)
+		return	0;
+
+	dev->resume_flag = 0;
+	dev->suspend_flag = 1;
+	ishtp_send_suspend(dev);
+
+	/* 25 ms should be enough for live ISH to flush all IPC buf */
+	if (dev->suspend_flag)
+		wait_event_interruptible_timeout(dev->suspend_wait,
+						 !dev->suspend_flag,
+						  msecs_to_jiffies(25));
+
+	return 0;
+}
+
+static DECLARE_WORK(resume_work, ish_resume_handler);
+/**
+ * ish_resume() - ISH resume callback
+ * @device:	device pointer
+ *
+ * ISH resume callback
+ *
+ * Return: 0 to the pm core
+ */
+static int ish_resume(struct device *device)
+{
+	struct pci_dev *pdev = to_pci_dev(device);
+	struct ishtp_device *dev = pci_get_drvdata(pdev);
+
+	ish_resume_device = device;
+	dev->resume_flag = 1;
+
+	disable_irq_wake(pdev->irq);
+	schedule_work(&resume_work);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static const struct dev_pm_ops ish_pm_ops = {
+	.suspend = ish_suspend,
+	.resume = ish_resume,
+};
+#define ISHTP_ISH_PM_OPS	(&ish_pm_ops)
+#else
+#define ISHTP_ISH_PM_OPS	NULL
+#endif
+
+static struct pci_driver ish_driver = {
+	.name = KBUILD_MODNAME,
+	.id_table = ish_pci_tbl,
+	.probe = ish_probe,
+	.remove = ish_remove,
+	.driver.pm = ISHTP_ISH_PM_OPS,
+};
+
+static int __init ish_driver_init(void)
+{
+	return pci_register_driver(&ish_driver);
+}
+
+static void __exit ish_driver_exit(void)
+{
+	pci_unregister_driver(&ish_driver);
+}
+
+module_init(ish_driver_init);
+module_exit(ish_driver_exit);
+
+/* Original author */
+MODULE_AUTHOR("Daniel Drubin <daniel.drubin@intel.com>");
+/* Adoption to upstream Linux kernel */
+MODULE_AUTHOR("Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>");
+
+MODULE_DESCRIPTION("Intel(R) Integrated Sensor Hub PCI Device Driver");
+MODULE_LICENSE("GPL");

drivers/hid/intel-ish-hid/ipc/utils.h

+/*
+ * Utility macros of ISH
+ *
+ * Copyright (c) 2014-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ */
+#ifndef UTILS__H
+#define UTILS__H
+
+#define	WAIT_FOR_SEND_SLICE	(HZ / 10)
+#define	WAIT_FOR_CONNECT_SLICE	(HZ / 10)
+
+/*
+ * Waits for specified event when a thread that triggers event can't signal
+ * Also, waits *at_least* `timeinc` after condition is satisfied
+ */
+#define	timed_wait_for(timeinc, condition)			\
+	do {							\
+		int completed = 0;				\
+		do {						\
+			unsigned long	j;			\
+			int	done = 0;			\
+								\
+			completed = (condition);		\
+			for (j = jiffies, done = 0; !done; ) {	\
+				schedule_timeout(timeinc);	\
+				if (time_is_before_eq_jiffies(j + timeinc)) \
+					done = 1;		\
+			}					\
+		} while (!(completed));				\
+	} while (0)
+
+
+/*
+ * Waits for specified event when a thread that triggers event
+ * can't signal with timeout (use whenever we may hang)
+ */
+#define	timed_wait_for_timeout(timeinc, condition, timeout)	\
+	do {							\
+		int	t = timeout;				\
+		do {						\
+			unsigned long	j;			\
+			int	done = 0;			\
+								\
+			for (j = jiffies, done = 0; !done; ) {	\
+				schedule_timeout(timeinc);	\
+				if (time_is_before_eq_jiffies(j + timeinc)) \
+					done = 1;		\
+			} \
+			t -= timeinc;				\
+			if (t <= 0)				\
+				break;				\
+		} while (!(condition));				\
+	} while (0)
+
+#endif /* UTILS__H */

include/trace/events/intel_ish.h

+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM intel_ish
+
+#if !defined(_TRACE_INTEL_ISH_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_INTEL_ISH_H
+
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(ishtp_dump,
+
+	TP_PROTO(const char *message),
+
+	TP_ARGS(message),
+
+	TP_STRUCT__entry(
+		__string(message, message)
+	),
+
+	TP_fast_assign(
+		__assign_str(message, message);
+	),
+
+	TP_printk("%s", __get_str(message))
+);
+
+
+#endif /* _TRACE_INTEL_ISH_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>