Re: [PATCH v2 04/22] HID: intel-thc-hid: intel-thc: Add THC PIO operation APIs

[Aaron Ma <aaron.ma@canonical.com>]

On 11/14/24 1:33 PM, Even Xu wrote:
> From: Xinpeng Sun <xinpeng.sun@intel.com>
> 
> THC PIO (programmed I/O) operations are very similar with general
> SPI/I2C read/write operation to access external slave device on the bus
> through internal FIFO.
> 
> THC PIO operations are split into 4 steps:
> 1. prepare: configure hardware with correct opcode, slave address, and
>              fill the PIO FIFO
> 2. start: set start bit to issue a bus send/receive
> 3. wait: wait for bus sending/receiving completion
> 4. complete: check send/receive data in FIFO and return
> 
> Co-developed-by: Even Xu <even.xu@intel.com>
> Signed-off-by: Even Xu <even.xu@intel.com>
> Signed-off-by: Xinpeng Sun <xinpeng.sun@intel.com>
> Tested-by: Rui Zhang <rui1.zhang@intel.com>
> Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
> ---
>   .../intel-thc-hid/intel-thc/intel-thc-dev.c   | 245 ++++++++++++++++++
>   .../intel-thc-hid/intel-thc/intel-thc-dev.h   |  24 ++
>   .../intel-thc-hid/intel-thc/intel-thc-hw.h    |  23 ++
>   3 files changed, 292 insertions(+)
> 
> diff --git a/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.c b/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.c
> index d77603e4c01e..0571b8270716 100644
> --- a/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.c
> +++ b/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.c
> @@ -1,9 +1,11 @@
>   /* SPDX-License-Identifier: GPL-2.0 */
>   /* Copyright (c) 2024 Intel Corporation */
>   
> +#include <linux/bitfield.h>
>   #include <linux/regmap.h>
>   
>   #include "intel-thc-dev.h"
> +#include "intel-thc-hw.h"
>   
>   static int thc_regmap_read(void *context, unsigned int reg,
>   			   unsigned int *val)
> @@ -76,10 +78,253 @@ struct thc_device *thc_dev_init(struct device *device, void __iomem *mem_addr)
>   		return ERR_PTR(ret);
>   	}
>   
> +	mutex_init(&thc_dev->thc_bus_lock);
> +
>   	return thc_dev;
>   }
>   EXPORT_SYMBOL_NS_GPL(thc_dev_init, INTEL_THC);



Since the commit in 6.13-rc1+ change the symbol namespace:
cdd30ebb1b9f ("module: Convert symbol namespace to string literal")

This should be changed to
EXPORT_SYMBOL_NS_GPL(thc_dev_init, "INTEL_THC");

There are many of them in this driver, better to define a helper macro in header file.
And group them consistently.

Aaron


>   
> +static int prepare_pio(const struct thc_device *dev, const u8 pio_op,
> +		       const u32 address, const u32 size)
> +{
> +	u32 sts, ctrl, addr, mask;
> +
> +	regmap_read(dev->thc_regmap, THC_M_PRT_SW_SEQ_STS_OFFSET, &sts);
> +
> +	/* Check if THC previous PIO still in progress */
> +	if (sts & THC_M_PRT_SW_SEQ_STS_THC_SS_CIP) {
> +		dev_err_once(dev->dev, "THC PIO is still busy!\n");
> +		return -EBUSY;
> +	}
> +
> +	/* Clear error bit and complete bit in state register */
> +	sts |= THC_M_PRT_SW_SEQ_STS_THC_SS_ERR |
> +	       THC_M_PRT_SW_SEQ_STS_TSSDONE;
> +	regmap_write(dev->thc_regmap, THC_M_PRT_SW_SEQ_STS_OFFSET, sts);
> +
> +	/* Set PIO data size, opcode and interrupt capability */
> +	ctrl = FIELD_PREP(THC_M_PRT_SW_SEQ_CNTRL_THC_SS_BC, size) |
> +	       FIELD_PREP(THC_M_PRT_SW_SEQ_CNTRL_THC_SS_CMD, pio_op);
> +	if (dev->pio_int_supported)
> +		ctrl |= THC_M_PRT_SW_SEQ_CNTRL_THC_SS_CD_IE;
> +
> +	mask = THC_M_PRT_SW_SEQ_CNTRL_THC_SS_BC |
> +	       THC_M_PRT_SW_SEQ_CNTRL_THC_SS_CMD |
> +	       THC_M_PRT_SW_SEQ_CNTRL_THC_SS_CD_IE;
> +	regmap_write_bits(dev->thc_regmap,
> +			  THC_M_PRT_SW_SEQ_CNTRL_OFFSET, mask, ctrl);
> +
> +	/* Set PIO target address */
> +	addr = FIELD_PREP(THC_M_PRT_SW_SEQ_DATA0_ADDR_THC_SW_SEQ_DATA0_ADDR, address);
> +	mask = THC_M_PRT_SW_SEQ_DATA0_ADDR_THC_SW_SEQ_DATA0_ADDR;
> +	regmap_write_bits(dev->thc_regmap,
> +			  THC_M_PRT_SW_SEQ_DATA0_ADDR_OFFSET, mask, addr);
> +	return 0;
> +}
> +
> +static void pio_start(const struct thc_device *dev,
> +		      u32 size_in_bytes, const u32 *buffer)
> +{
> +	if (size_in_bytes && buffer)
> +		regmap_bulk_write(dev->thc_regmap, THC_M_PRT_SW_SEQ_DATA1_OFFSET,
> +				  buffer, size_in_bytes / sizeof(u32));
> +
> +	/* Enable Start bit */
> +	regmap_write_bits(dev->thc_regmap,
> +			  THC_M_PRT_SW_SEQ_CNTRL_OFFSET,
> +			  THC_M_PRT_SW_SEQ_CNTRL_TSSGO,
> +			  THC_M_PRT_SW_SEQ_CNTRL_TSSGO);
> +}
> +
> +static int pio_complete(const struct thc_device *dev,
> +			u32 *buffer, u32 *size)
> +{
> +	u32 sts, ctrl;
> +
> +	regmap_read(dev->thc_regmap, THC_M_PRT_SW_SEQ_STS_OFFSET, &sts);
> +	if (sts & THC_M_PRT_SW_SEQ_STS_THC_SS_ERR) {
> +		dev_err_once(dev->dev, "PIO operation error\n");
> +		return -EBUSY;
> +	}
> +
> +	if (buffer && size) {
> +		regmap_read(dev->thc_regmap, THC_M_PRT_SW_SEQ_CNTRL_OFFSET, &ctrl);
> +		*size = FIELD_GET(THC_M_PRT_SW_SEQ_CNTRL_THC_SS_BC, ctrl);
> +
> +		regmap_bulk_read(dev->thc_regmap, THC_M_PRT_SW_SEQ_DATA1_OFFSET,
> +				 buffer, *size / sizeof(u32));
> +	}
> +
> +	sts |= THC_M_PRT_SW_SEQ_STS_THC_SS_ERR | THC_M_PRT_SW_SEQ_STS_TSSDONE;
> +	regmap_write(dev->thc_regmap, THC_M_PRT_SW_SEQ_STS_OFFSET, sts);
> +	return 0;
> +}
> +
> +static int pio_wait(const struct thc_device *dev)
> +{
> +	u32 sts = 0;
> +	int ret;
> +
> +	ret = regmap_read_poll_timeout(dev->thc_regmap, THC_M_PRT_SW_SEQ_STS_OFFSET, sts,
> +				       !(sts & THC_M_PRT_SW_SEQ_STS_THC_SS_CIP ||
> +				       !(sts & THC_M_PRT_SW_SEQ_STS_TSSDONE)),
> +				       THC_REGMAP_POLLING_INTERVAL_US, THC_PIO_DONE_TIMEOUT_US);
> +	if (ret)
> +		dev_err_once(dev->dev, "Timeout while polling PIO operation done\n");
> +
> +	return ret;
> +}
> +
> +/**
> + * thc_tic_pio_read - Read data from touch device by PIO
> + *
> + * @dev: The pointer of THC private device context
> + * @address: Slave address for the PIO operation
> + * @size: Expected read data size
> + * @actual_size: The pointer of the actual data size read from touch device
> + * @buffer: The pointer of data buffer to store the data read from touch device
> + *
> + * Return: 0 on success, other error codes on failed.
> + */
> +int thc_tic_pio_read(struct thc_device *dev, const u32 address,
> +		     const u32 size, u32 *actual_size, u32 *buffer)
> +{
> +	u8 opcode;
> +	int ret;
> +
> +	if (size <= 0 || !actual_size || !buffer) {
> +		dev_err(dev->dev, "Invalid input parameters, size %u, actual_size %p, buffer %p\n",
> +			size, actual_size, buffer);
> +		return -EINVAL;
> +	}
> +
> +	if (mutex_lock_interruptible(&dev->thc_bus_lock))
> +		return -EINTR;
> +
> +	opcode = (dev->port_type == THC_PORT_TYPE_SPI) ?
> +		 THC_PIO_OP_SPI_TIC_READ : THC_PIO_OP_I2C_TIC_READ;
> +
> +	ret = prepare_pio(dev, opcode, address, size);
> +	if (ret < 0)
> +		goto end;
> +
> +	pio_start(dev, 0, NULL);
> +
> +	ret = pio_wait(dev);
> +	if (ret < 0)
> +		goto end;
> +
> +	ret = pio_complete(dev, buffer, actual_size);
> +
> +end:
> +	mutex_unlock(&dev->thc_bus_lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL_NS_GPL(thc_tic_pio_read, INTEL_THC);
> +
> +/**
> + * thc_tic_pio_write - Write data to touch device by PIO
> + *
> + * @dev: The pointer of THC private device context
> + * @address: Slave address for the PIO operation
> + * @size: PIO write data size
> + * @buffer: The pointer of the write data buffer
> + *
> + * Return: 0 on success, other error codes on failed.
> + */
> +int thc_tic_pio_write(struct thc_device *dev, const u32 address,
> +		      const u32 size, const u32 *buffer)
> +{
> +	u8 opcode;
> +	int ret;
> +
> +	if (size <= 0 || !buffer) {
> +		dev_err(dev->dev, "Invalid input parameters, size %u, buffer %p\n",
> +			size, buffer);
> +		return -EINVAL;
> +	}
> +
> +	if (mutex_lock_interruptible(&dev->thc_bus_lock))
> +		return -EINTR;
> +
> +	opcode = (dev->port_type == THC_PORT_TYPE_SPI) ?
> +		 THC_PIO_OP_SPI_TIC_WRITE : THC_PIO_OP_I2C_TIC_WRITE;
> +
> +	ret = prepare_pio(dev, opcode, address, size);
> +	if (ret < 0)
> +		goto end;
> +
> +	pio_start(dev, size, buffer);
> +
> +	ret = pio_wait(dev);
> +	if (ret < 0)
> +		goto end;
> +
> +	ret = pio_complete(dev, NULL, NULL);
> +
> +end:
> +	mutex_unlock(&dev->thc_bus_lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL_NS_GPL(thc_tic_pio_write, INTEL_THC);
> +
> +/**
> + * thc_tic_pio_write_and_read - Write data followed by read data by PIO
> + *
> + * @dev: The pointer of THC private device context
> + * @address: Slave address for the PIO operation
> + * @write_size: PIO write data size
> + * @write_buffer: The pointer of the write data buffer
> + * @read_size: Expected PIO read data size
> + * @actual_size: The pointer of the actual read data size
> + * @read_buffer: The pointer of PIO read data buffer
> + *
> + * Return: 0 on success, other error codes on failed.
> + */
> +int thc_tic_pio_write_and_read(struct thc_device *dev, const u32 address,
> +			       const u32 write_size, const u32 *write_buffer,
> +			       const u32 read_size, u32 *actual_size, u32 *read_buffer)
> +{
> +	u32 i2c_ctrl, mask;
> +	int ret;
> +
> +	if (dev->port_type == THC_PORT_TYPE_SPI) {
> +		dev_err(dev->dev, "SPI port type doesn't support pio write and read!");
> +		return -EINVAL;
> +	}
> +
> +	if (mutex_lock_interruptible(&dev->thc_bus_lock))
> +		return -EINTR;
> +
> +	/* Config i2c PIO write and read sequence */
> +	i2c_ctrl = FIELD_PREP(THC_M_PRT_SW_SEQ_I2C_WR_CNTRL_THC_PIO_I2C_WBC, write_size);
> +	mask = THC_M_PRT_SW_SEQ_I2C_WR_CNTRL_THC_PIO_I2C_WBC;
> +
> +	regmap_write_bits(dev->thc_regmap, THC_M_PRT_SW_SEQ_I2C_WR_CNTRL_OFFSET,
> +			  mask, i2c_ctrl);
> +
> +	regmap_write_bits(dev->thc_regmap, THC_M_PRT_SW_SEQ_I2C_WR_CNTRL_OFFSET,
> +			  THC_M_PRT_SW_SEQ_I2C_WR_CNTRL_THC_I2C_RW_PIO_EN,
> +			  THC_M_PRT_SW_SEQ_I2C_WR_CNTRL_THC_I2C_RW_PIO_EN);
> +
> +	ret = prepare_pio(dev, THC_PIO_OP_I2C_TIC_WRITE_AND_READ, address, read_size);
> +	if (ret < 0)
> +		goto end;
> +
> +	pio_start(dev, write_size, write_buffer);
> +
> +	ret = pio_wait(dev);
> +	if (ret < 0)
> +		goto end;
> +
> +	ret = pio_complete(dev, read_buffer, actual_size);
> +
> +end:
> +	mutex_unlock(&dev->thc_bus_lock);
> +	return ret;
> +}
> +EXPORT_SYMBOL_NS_GPL(thc_tic_pio_write_and_read, INTEL_THC);
> +
>   MODULE_AUTHOR("Xinpeng Sun <xinpeng.sun@intel.com>");
>   MODULE_AUTHOR("Even Xu <even.xu@intel.com>");
>   
> diff --git a/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.h b/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.h
> index 7060f0a36cbd..88a9f606a6a9 100644
> --- a/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.h
> +++ b/drivers/hid/intel-thc-hid/intel-thc/intel-thc-dev.h
> @@ -5,21 +5,45 @@
>   #define _INTEL_THC_DEV_H_
>   
>   #include <linux/cdev.h>
> +#include <linux/mutex.h>
>   
>   #define THC_REGMAP_COMMON_OFFSET  0x10
>   #define THC_REGMAP_MMIO_OFFSET    0x1000
>   
> +/*
> + * THC Port type
> + * @THC_PORT_TYPE_SPI: This port is used for HIDSPI
> + * @THC_PORT_TYPE_I2C: This port is used for HIDI2C
> + */
> +enum thc_port_type {
> +	THC_PORT_TYPE_SPI = 0,
> +	THC_PORT_TYPE_I2C = 1,
> +};
> +
>   /**
>    * struct thc_device - THC private device struct
>    * @thc_regmap: MMIO regmap structure for accessing THC registers
>    * @mmio_addr: MMIO registers address
> + * @thc_bus_lock: mutex locker for THC config
> + * @port_type: port type of THC port instance
> + * @pio_int_supported: PIO interrupt supported flag
>    */
>   struct thc_device {
>   	struct device *dev;
>   	struct regmap *thc_regmap;
>   	void __iomem *mmio_addr;
> +	struct mutex thc_bus_lock;
> +	enum thc_port_type port_type;
> +	bool pio_int_supported;
>   };
>   
>   struct thc_device *thc_dev_init(struct device *device, void __iomem *mem_addr);
> +int thc_tic_pio_read(struct thc_device *dev, const u32 address,
> +		     const u32 size, u32 *actual_size, u32 *buffer);
> +int thc_tic_pio_write(struct thc_device *dev, const u32 address,
> +		      const u32 size, const u32 *buffer);
> +int thc_tic_pio_write_and_read(struct thc_device *dev, const u32 address,
> +			       const u32 write_size, const u32 *write_buffer,
> +			       const u32 read_size, u32 *actual_size, u32 *read_buffer);
>   
>   #endif /* _INTEL_THC_DEV_H_ */
> diff --git a/drivers/hid/intel-thc-hid/intel-thc/intel-thc-hw.h b/drivers/hid/intel-thc-hid/intel-thc/intel-thc-hw.h
> index 77b275a400d5..9f5f39dcedcd 100644
> --- a/drivers/hid/intel-thc-hid/intel-thc/intel-thc-hw.h
> +++ b/drivers/hid/intel-thc-hid/intel-thc/intel-thc-hw.h
> @@ -633,4 +633,27 @@
>   
>   #define THC_M_PRT_SW_DMA_PRD_TABLE_LEN_THC_M_PRT_SW_DMA_PRD_TABLE_LEN	GENMASK(23, 0)
>   
> +#define THC_REGMAP_POLLING_INTERVAL_US		10 /* 10us */
> +#define THC_PIO_DONE_TIMEOUT_US			USEC_PER_SEC /* 1s */
> +
> +/*
> + * THC PIO opcode default value
> + * @THC_PIO_OP_SPI_TIC_READ: THC opcode for SPI PIO read
> + * @THC_PIO_OP_SPI_TIC_WRITE: THC opcode for SPI PIO write
> + * @THC_PIO_OP_I2C_SUBSYSTEM_READ: THC opcode for read I2C subsystem registers
> + * @THC_PIO_OP_I2C_SUBSYSTEM_WRITE: THC opcode for write I2C subsystem registers
> + * @THC_PIO_OP_I2C_TIC_READ: THC opcode for read I2C device
> + * @THC_PIO_OP_I2C_TIC_WRITE: THC opcode for write I2C device
> + * @THC_PIO_OP_I2C_TIC_WRITE_AND_READ: THC opcode for write followed by read I2C device
> + */
> +enum thc_pio_opcode {
> +	THC_PIO_OP_SPI_TIC_READ = 0x4,
> +	THC_PIO_OP_SPI_TIC_WRITE = 0x6,
> +	THC_PIO_OP_I2C_SUBSYSTEM_READ = 0x12,
> +	THC_PIO_OP_I2C_SUBSYSTEM_WRITE = 0x13,
> +	THC_PIO_OP_I2C_TIC_READ = 0x14,
> +	THC_PIO_OP_I2C_TIC_WRITE = 0x18,
> +	THC_PIO_OP_I2C_TIC_WRITE_AND_READ = 0x1C,
> +};
> +
>   #endif /* _INTEL_THC_HW_H_  */