[PATCH v4 04/22] HID: intel-thc-hid: intel-thc: Add THC PIO operation APIs

Even Xu
2025-01-06T02:32:20Z

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>
Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
---
.../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 de7a0ed38c25..397250c38ae7 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)
@@ -208,10 +210,253 @@ struct thc_device *thc_dev_init(struct device *device, void __iomem *mem_addr)

thc_clear_state(thc_dev);

+ mutex_init(&thc_dev->thc_bus_lock);
+
return thc_dev;
}
EXPORT_SYMBOL_NS_GPL(thc_dev_init, "INTEL_THC");

+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 8b3a962e7e64..60f5f657be62 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
@@ -636,4 +636,27 @@

#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_ */
--
2.40.1