drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_spi.c - kernel/msm-4.9 - Gitiles

 /*
  * Synaptics DSX touchscreen driver
  *
  * Copyright (C) 2012-2015 Synaptics Incorporated. All rights reserved.
  *
  * Copyright (C) 2012 Alexandra Chin <alexandra.chin@tw.synaptics.com>
  * Copyright (C) 2012 Scott Lin <scott.lin@tw.synaptics.com>
  *
  * 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; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that 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.
  *
  * INFORMATION CONTAINED IN THIS DOCUMENT IS PROVIDED "AS-IS," AND SYNAPTICS
  * EXPRESSLY DISCLAIMS ALL EXPRESS AND IMPLIED WARRANTIES, INCLUDING ANY
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE,
  * AND ANY WARRANTIES OF NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHTS.
  * IN NO EVENT SHALL SYNAPTICS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES ARISING OUT OF OR IN CONNECTION
  * WITH THE USE OF THE INFORMATION CONTAINED IN THIS DOCUMENT, HOWEVER CAUSED
  * AND BASED ON ANY THEORY OF LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  * NEGLIGENCE OR OTHER TORTIOUS ACTION, AND EVEN IF SYNAPTICS WAS ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE. IF A TRIBUNAL OF COMPETENT JURISDICTION DOES
  * NOT PERMIT THE DISCLAIMER OF DIRECT DAMAGES OR ANY OTHER DAMAGES, SYNAPTICS'
  * TOTAL CUMULATIVE LIABILITY TO ANY PARTY SHALL NOT EXCEED ONE HUNDRED U.S.
  * DOLLARS.
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/spi/spi.h>
 #include <linux/delay.h>
 #include <linux/input.h>
 #include <linux/types.h>
 #include <linux/of_gpio.h>
 #include <linux/platform_device.h>
 #include <linux/input/synaptics_dsx_v2_6.h>
 #include "synaptics_dsx_core.h"

 #define SPI_READ 0x80
 #define SPI_WRITE 0x00

 #ifdef CONFIG_OF
 static int parse_dt(struct device *dev, struct synaptics_dsx_board_data *bdata)
 {
 	int retval;
 	u32 value;
 	const char *name;
 	struct property *prop;
 	struct device_node *np = dev->of_node;

 	bdata->irq_gpio = of_get_named_gpio_flags(np,
 			"synaptics,irq-gpio", 0,
 			(enum of_gpio_flags *)&bdata->irq_flags);

 	retval = of_property_read_u32(np, "synaptics,irq-on-state",
 			&value);
 	if (retval < 0)
 		bdata->irq_on_state = 0;
 	else
 		bdata->irq_on_state = value;

 	retval = of_property_read_string(np, "synaptics,pwr-reg-name", &name);
 	if (retval < 0)
 		bdata->pwr_reg_name = NULL;
 	else
 		bdata->pwr_reg_name = name;

 	retval = of_property_read_string(np, "synaptics,bus-reg-name", &name);
 	if (retval < 0)
 		bdata->bus_reg_name = NULL;
 	else
 		bdata->bus_reg_name = name;

 	prop = of_find_property(np, "synaptics,power-gpio", NULL);
 	if (prop && prop->length) {
 		bdata->power_gpio = of_get_named_gpio_flags(np,
 				"synaptics,power-gpio", 0, NULL);
 		retval = of_property_read_u32(np, "synaptics,power-on-state",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,power-on-state property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->power_on_state = value;
 		}
 	} else {
 		bdata->power_gpio = -1;
 	}

 	prop = of_find_property(np, "synaptics,power-delay-ms", NULL);
 	if (prop && prop->length) {
 		retval = of_property_read_u32(np, "synaptics,power-delay-ms",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,power-delay-ms property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->power_delay_ms = value;
 		}
 	} else {
 		bdata->power_delay_ms = 0;
 	}

 	prop = of_find_property(np, "synaptics,reset-gpio", NULL);
 	if (prop && prop->length) {
 		bdata->reset_gpio = of_get_named_gpio_flags(np,
 				"synaptics,reset-gpio", 0, NULL);
 		retval = of_property_read_u32(np, "synaptics,reset-on-state",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,reset-on-state property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->reset_on_state = value;
 		}
 		retval = of_property_read_u32(np, "synaptics,reset-active-ms",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,reset-active-ms property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->reset_active_ms = value;
 		}
 	} else {
 		bdata->reset_gpio = -1;
 	}

 	prop = of_find_property(np, "synaptics,reset-delay-ms", NULL);
 	if (prop && prop->length) {
 		retval = of_property_read_u32(np, "synaptics,reset-delay-ms",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,reset-delay-ms property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->reset_delay_ms = value;
 		}
 	} else {
 		bdata->reset_delay_ms = 0;
 	}

 	prop = of_find_property(np, "synaptics,byte-delay-us", NULL);
 	if (prop && prop->length) {
 		retval = of_property_read_u32(np, "synaptics,byte-delay-us",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,byte-delay-us property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->byte_delay_us = value;
 		}
 	} else {
 		bdata->byte_delay_us = 0;
 	}

 	prop = of_find_property(np, "synaptics,block-delay-us", NULL);
 	if (prop && prop->length) {
 		retval = of_property_read_u32(np, "synaptics,block-delay-us",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,block-delay-us property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->block_delay_us = value;
 		}
 	} else {
 		bdata->block_delay_us = 0;
 	}

 	prop = of_find_property(np, "synaptics,max-y-for-2d", NULL);
 	if (prop && prop->length) {
 		retval = of_property_read_u32(np, "synaptics,max-y-for-2d",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,max-y-for-2d property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->max_y_for_2d = value;
 		}
 	} else {
 		bdata->max_y_for_2d = -1;
 	}

 	prop = of_find_property(np, "synaptics,swap-axes", NULL);
 	bdata->swap_axes = prop > 0 ? true : false;

 	prop = of_find_property(np, "synaptics,x-flip", NULL);
 	bdata->x_flip = prop > 0 ? true : false;

 	prop = of_find_property(np, "synaptics,y-flip", NULL);
 	bdata->y_flip = prop > 0 ? true : false;

 	prop = of_find_property(np, "synaptics,ub-i2c-addr", NULL);
 	if (prop && prop->length) {
 		retval = of_property_read_u32(np, "synaptics,ub-i2c-addr",
 				&value);
 		if (retval < 0) {
 			dev_err(dev, "%s: Unable to read synaptics,ub-i2c-addr property\n",
 					__func__);
 			return retval;
 		} else {
 			bdata->ub_i2c_addr = (unsigned short)value;
 		}
 	} else {
 		bdata->ub_i2c_addr = -1;
 	}

 	prop = of_find_property(np, "synaptics,cap-button-codes", NULL);
 	if (prop && prop->length) {
 		bdata->cap_button_map->map = devm_kzalloc(dev,
 				prop->length,
 				GFP_KERNEL);
 		if (!bdata->cap_button_map->map)
 			return -ENOMEM;
 		bdata->cap_button_map->nbuttons = prop->length / sizeof(u32);
 		retval = of_property_read_u32_array(np,
 				"synaptics,cap-button-codes",
 				bdata->cap_button_map->map,
 				bdata->cap_button_map->nbuttons);
 		if (retval < 0) {
 			bdata->cap_button_map->nbuttons = 0;
 			bdata->cap_button_map->map = NULL;
 		}
 	} else {
 		bdata->cap_button_map->nbuttons = 0;
 		bdata->cap_button_map->map = NULL;
 	}

 	prop = of_find_property(np, "synaptics,vir-button-codes", NULL);
 	if (prop && prop->length) {
 		bdata->vir_button_map->map = devm_kzalloc(dev,
 				prop->length,
 				GFP_KERNEL);
 		if (!bdata->vir_button_map->map)
 			return -ENOMEM;
 		bdata->vir_button_map->nbuttons = prop->length / sizeof(u32);
 		bdata->vir_button_map->nbuttons /= 5;
 		retval = of_property_read_u32_array(np,
 				"synaptics,vir-button-codes",
 				bdata->vir_button_map->map,
 				bdata->vir_button_map->nbuttons * 5);
 		if (retval < 0) {
 			bdata->vir_button_map->nbuttons = 0;
 			bdata->vir_button_map->map = NULL;
 		}
 	} else {
 		bdata->vir_button_map->nbuttons = 0;
 		bdata->vir_button_map->map = NULL;
 	}

 	return 0;
 }
 #endif

 static int synaptics_rmi4_spi_set_page(struct synaptics_rmi4_data *rmi4_data,
 		unsigned short addr)
 {
 	int retval;
 	unsigned int index;
 	unsigned int xfer_count = PAGE_SELECT_LEN + 1;
 	unsigned char txbuf[xfer_count];
 	unsigned char page;
 	struct spi_message msg;
 	struct spi_transfer xfers[xfer_count];
 	struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
 	const struct synaptics_dsx_board_data *bdata =
 			rmi4_data->hw_if->board_data;

 	page = ((addr >> 8) & ~MASK_7BIT);
 	if (page != rmi4_data->current_page) {
 		spi_message_init(&msg);

 		txbuf[0] = SPI_WRITE;
 		txbuf[1] = MASK_8BIT;
 		txbuf[2] = page;

 		for (index = 0; index < xfer_count; index++) {
 			memset(&xfers[index], 0, sizeof(struct spi_transfer));
 			xfers[index].len = 1;
 			xfers[index].delay_usecs = bdata->byte_delay_us;
 			xfers[index].tx_buf = &txbuf[index];
 			spi_message_add_tail(&xfers[index], &msg);
 		}

 		if (bdata->block_delay_us)
 			xfers[index - 1].delay_usecs = bdata->block_delay_us;

 		retval = spi_sync(spi, &msg);
 		if (retval == 0) {
 			rmi4_data->current_page = page;
 			retval = PAGE_SELECT_LEN;
 		} else {
 			dev_err(rmi4_data->pdev->dev.parent,
 					"%s: Failed to complete SPI transfer, error = %d\n",
 					__func__, retval);
 		}
 	} else {
 		retval = PAGE_SELECT_LEN;
 	}

 	return retval;
 }

 static int synaptics_rmi4_spi_read(struct synaptics_rmi4_data *rmi4_data,
 		unsigned short addr, unsigned char *data, unsigned short length)
 {
 	int retval;
 	unsigned int index;
 	unsigned int xfer_count = length + ADDRESS_WORD_LEN;
 	unsigned char txbuf[ADDRESS_WORD_LEN];
 	unsigned char *rxbuf = NULL;
 	struct spi_message msg;
 	struct spi_transfer *xfers = NULL;
 	struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
 	const struct synaptics_dsx_board_data *bdata =
 			rmi4_data->hw_if->board_data;

 	spi_message_init(&msg);

 	xfers = kcalloc(xfer_count, sizeof(struct spi_transfer), GFP_KERNEL);
 	if (!xfers) {
 		dev_err(rmi4_data->pdev->dev.parent,
 				"%s: Failed to allocate memory for xfers\n",
 				__func__);
 		retval = -ENOMEM;
 		goto exit;
 	}

 	txbuf[0] = (addr >> 8) | SPI_READ;
 	txbuf[1] = addr & MASK_8BIT;

 	rxbuf = kmalloc(length, GFP_KERNEL);
 	if (!rxbuf) {
 		dev_err(rmi4_data->pdev->dev.parent,
 				"%s: Failed to allocate memory for rxbuf\n",
 				__func__);
 		retval = -ENOMEM;
 		goto exit;
 	}

 	mutex_lock(&rmi4_data->rmi4_io_ctrl_mutex);

 	retval = synaptics_rmi4_spi_set_page(rmi4_data, addr);
 	if (retval != PAGE_SELECT_LEN) {
 		mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);
 		retval = -EIO;
 		goto exit;
 	}

 	for (index = 0; index < xfer_count; index++) {
 		xfers[index].len = 1;
 		xfers[index].delay_usecs = bdata->byte_delay_us;
 		if (index < ADDRESS_WORD_LEN)
 			xfers[index].tx_buf = &txbuf[index];
 		else
 			xfers[index].rx_buf = &rxbuf[index - ADDRESS_WORD_LEN];
 		spi_message_add_tail(&xfers[index], &msg);
 	}

 	if (bdata->block_delay_us)
 		xfers[index - 1].delay_usecs = bdata->block_delay_us;

 	retval = spi_sync(spi, &msg);
 	if (retval == 0) {
 		retval = secure_memcpy(data, length, rxbuf, length, length);
 		if (retval < 0) {
 			dev_err(rmi4_data->pdev->dev.parent,
 					"%s: Failed to copy data\n",
 					__func__);
 		} else {
 			retval = length;
 		}
 	} else {
 		dev_err(rmi4_data->pdev->dev.parent,
 				"%s: Failed to complete SPI transfer, error = %d\n",
 				__func__, retval);
 	}

 	mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);

 exit:
 	kfree(rxbuf);
 	kfree(xfers);

 	return retval;
 }

 static int synaptics_rmi4_spi_write(struct synaptics_rmi4_data *rmi4_data,
 		unsigned short addr, unsigned char *data, unsigned short length)
 {
 	int retval;
 	unsigned int index;
 	unsigned int xfer_count = length + ADDRESS_WORD_LEN;
 	unsigned char *txbuf = NULL;
 	struct spi_message msg;
 	struct spi_transfer *xfers = NULL;
 	struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
 	const struct synaptics_dsx_board_data *bdata =
 			rmi4_data->hw_if->board_data;

 	spi_message_init(&msg);

 	xfers = kcalloc(xfer_count, sizeof(struct spi_transfer), GFP_KERNEL);
 	if (!xfers) {
 		dev_err(rmi4_data->pdev->dev.parent,
 				"%s: Failed to allocate memory for xfers\n",
 				__func__);
 		retval = -ENOMEM;
 		goto exit;
 	}

 	txbuf = kmalloc(xfer_count, GFP_KERNEL);
 	if (!txbuf) {
 		dev_err(rmi4_data->pdev->dev.parent,
 				"%s: Failed to allocate memory for txbuf\n",
 				__func__);
 		retval = -ENOMEM;
 		goto exit;
 	}

 	txbuf[0] = (addr >> 8) & ~SPI_READ;
 	txbuf[1] = addr & MASK_8BIT;
 	retval = secure_memcpy(&txbuf[ADDRESS_WORD_LEN],
 			xfer_count - ADDRESS_WORD_LEN, data, length, length);
 	if (retval < 0) {
 		dev_err(rmi4_data->pdev->dev.parent,
 				"%s: Failed to copy data\n",
 				__func__);
 		goto exit;
 	}

 	mutex_lock(&rmi4_data->rmi4_io_ctrl_mutex);

 	retval = synaptics_rmi4_spi_set_page(rmi4_data, addr);
 	if (retval != PAGE_SELECT_LEN) {
 		mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);
 		retval = -EIO;
 		goto exit;
 	}

 	for (index = 0; index < xfer_count; index++) {
 		xfers[index].len = 1;
 		xfers[index].delay_usecs = bdata->byte_delay_us;
 		xfers[index].tx_buf = &txbuf[index];
 		spi_message_add_tail(&xfers[index], &msg);
 	}

 	if (bdata->block_delay_us)
 		xfers[index - 1].delay_usecs = bdata->block_delay_us;

 	retval = spi_sync(spi, &msg);
 	if (retval == 0) {
 		retval = length;
 	} else {
 		dev_err(rmi4_data->pdev->dev.parent,
 				"%s: Failed to complete SPI transfer, error = %d\n",
 				__func__, retval);
 	}

 	mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);

 exit:
 	kfree(txbuf);
 	kfree(xfers);

 	return retval;
 }

 static struct synaptics_dsx_bus_access bus_access = {
 	.type = BUS_SPI,
 	.read = synaptics_rmi4_spi_read,
 	.write = synaptics_rmi4_spi_write,
 };

 static struct synaptics_dsx_hw_interface hw_if;

 static struct platform_device *synaptics_dsx_spi_device;

 static void synaptics_rmi4_spi_dev_release(struct device *dev)
 {
 	kfree(synaptics_dsx_spi_device);

 	return;
 }

 static int synaptics_rmi4_spi_probe(struct spi_device *spi)
 {
 	int retval;

 	if (spi->master->flags & SPI_MASTER_HALF_DUPLEX) {
 		dev_err(&spi->dev,
 				"%s: Full duplex not supported by host\n",
 				__func__);
 		return -EIO;
 	}

 	synaptics_dsx_spi_device = kzalloc(
 			sizeof(struct platform_device),
 			GFP_KERNEL);
 	if (!synaptics_dsx_spi_device) {
 		dev_err(&spi->dev,
 				"%s: Failed to allocate memory for synaptics_dsx_spi_device\n",
 				__func__);
 		return -ENOMEM;
 	}

 #ifdef CONFIG_OF
 	if (spi->dev.of_node) {
 		hw_if.board_data = devm_kzalloc(&spi->dev,
 				sizeof(struct synaptics_dsx_board_data),
 				GFP_KERNEL);
 		if (!hw_if.board_data) {
 			dev_err(&spi->dev,
 					"%s: Failed to allocate memory for board data\n",
 					__func__);
 			return -ENOMEM;
 		}
 		hw_if.board_data->cap_button_map = devm_kzalloc(&spi->dev,
 				sizeof(struct synaptics_dsx_button_map),
 				GFP_KERNEL);
 		if (!hw_if.board_data->cap_button_map) {
 			dev_err(&spi->dev,
 					"%s: Failed to allocate memory for 0D button map\n",
 					__func__);
 			return -ENOMEM;
 		}
 		hw_if.board_data->vir_button_map = devm_kzalloc(&spi->dev,
 				sizeof(struct synaptics_dsx_button_map),
 				GFP_KERNEL);
 		if (!hw_if.board_data->vir_button_map) {
 			dev_err(&spi->dev,
 					"%s: Failed to allocate memory for virtual button map\n",
 					__func__);
 			return -ENOMEM;
 		}
 		parse_dt(&spi->dev, hw_if.board_data);
 	}
 #else
 	hw_if.board_data = spi->dev.platform_data;
 #endif

 	hw_if.bus_access = &bus_access;

 	spi->bits_per_word = 8;
 	spi->mode = SPI_MODE_3;

 	retval = spi_setup(spi);
 	if (retval < 0) {
 		dev_err(&spi->dev,
 				"%s: Failed to perform SPI setup\n",
 				__func__);
 		return retval;
 	}

 	synaptics_dsx_spi_device->name = PLATFORM_DRIVER_NAME;
 	synaptics_dsx_spi_device->id = 0;
 	synaptics_dsx_spi_device->num_resources = 0;
 	synaptics_dsx_spi_device->dev.parent = &spi->dev;
 	synaptics_dsx_spi_device->dev.platform_data = &hw_if;
 	synaptics_dsx_spi_device->dev.release = synaptics_rmi4_spi_dev_release;

 	retval = platform_device_register(synaptics_dsx_spi_device);
 	if (retval) {
 		dev_err(&spi->dev,
 				"%s: Failed to register platform device\n",
 				__func__);
 		return -ENODEV;
 	}

 	return 0;
 }

 static int synaptics_rmi4_spi_remove(struct spi_device *spi)
 {
 	platform_device_unregister(synaptics_dsx_spi_device);

 	return 0;
 }

 #ifdef CONFIG_OF
 static struct of_device_id synaptics_rmi4_of_match_table[] = {
 	{
 		.compatible = "synaptics,dsx-spi",
 	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, synaptics_rmi4_of_match_table);
 #else
 #define synaptics_rmi4_of_match_table NULL
 #endif

 static struct spi_driver synaptics_rmi4_spi_driver = {
 	.driver = {
 		.name = SPI_DRIVER_NAME,
 		.owner = THIS_MODULE,
 		.of_match_table = synaptics_rmi4_of_match_table,
 	},
 	.probe = synaptics_rmi4_spi_probe,
 	.remove = synaptics_rmi4_spi_remove,
 };


 int synaptics_rmi4_bus_init_v26(void)
 {
 	return spi_register_driver(&synaptics_rmi4_spi_driver);
 }
 EXPORT_SYMBOL(synaptics_rmi4_bus_init_v26);

 void synaptics_rmi4_bus_exit_v26(void)
 {
 	spi_unregister_driver(&synaptics_rmi4_spi_driver);

 	return;
 }
 EXPORT_SYMBOL(synaptics_rmi4_bus_exit_v26);

 MODULE_AUTHOR("Synaptics, Inc.");
 MODULE_DESCRIPTION("Synaptics DSX SPI Bus Support Module");
 MODULE_LICENSE("GPL v2");
	/*
	* Synaptics DSX touchscreen driver
	*
	* Copyright (C) 2012-2015 Synaptics Incorporated. All rights reserved.
	*
	* Copyright (C) 2012 Alexandra Chin <alexandra.chin@tw.synaptics.com>
	* Copyright (C) 2012 Scott Lin <scott.lin@tw.synaptics.com>
	*
	* 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; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that 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.
	*
	* INFORMATION CONTAINED IN THIS DOCUMENT IS PROVIDED "AS-IS," AND SYNAPTICS
	* EXPRESSLY DISCLAIMS ALL EXPRESS AND IMPLIED WARRANTIES, INCLUDING ANY
	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE,
	* AND ANY WARRANTIES OF NON-INFRINGEMENT OF ANY INTELLECTUAL PROPERTY RIGHTS.
	* IN NO EVENT SHALL SYNAPTICS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES ARISING OUT OF OR IN CONNECTION
	* WITH THE USE OF THE INFORMATION CONTAINED IN THIS DOCUMENT, HOWEVER CAUSED
	* AND BASED ON ANY THEORY OF LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
	* NEGLIGENCE OR OTHER TORTIOUS ACTION, AND EVEN IF SYNAPTICS WAS ADVISED OF
	* THE POSSIBILITY OF SUCH DAMAGE. IF A TRIBUNAL OF COMPETENT JURISDICTION DOES
	* NOT PERMIT THE DISCLAIMER OF DIRECT DAMAGES OR ANY OTHER DAMAGES, SYNAPTICS'
	* TOTAL CUMULATIVE LIABILITY TO ANY PARTY SHALL NOT EXCEED ONE HUNDRED U.S.
	* DOLLARS.
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/spi/spi.h>
	#include <linux/delay.h>
	#include <linux/input.h>
	#include <linux/types.h>
	#include <linux/of_gpio.h>
	#include <linux/platform_device.h>
	#include <linux/input/synaptics_dsx_v2_6.h>
	#include "synaptics_dsx_core.h"

	#define SPI_READ 0x80
	#define SPI_WRITE 0x00

	#ifdef CONFIG_OF
	static int parse_dt(struct device dev, struct synaptics_dsx_board_data bdata)
	{
	int retval;
	u32 value;
	const char *name;
	struct property *prop;
	struct device_node *np = dev->of_node;

	bdata->irq_gpio = of_get_named_gpio_flags(np,
	"synaptics,irq-gpio", 0,
	(enum of_gpio_flags *)&bdata->irq_flags);

	retval = of_property_read_u32(np, "synaptics,irq-on-state",
	&value);
	if (retval < 0)
	bdata->irq_on_state = 0;
	else
	bdata->irq_on_state = value;

	retval = of_property_read_string(np, "synaptics,pwr-reg-name", &name);
	if (retval < 0)
	bdata->pwr_reg_name = NULL;
	else
	bdata->pwr_reg_name = name;

	retval = of_property_read_string(np, "synaptics,bus-reg-name", &name);
	if (retval < 0)
	bdata->bus_reg_name = NULL;
	else
	bdata->bus_reg_name = name;

	prop = of_find_property(np, "synaptics,power-gpio", NULL);
	if (prop && prop->length) {
	bdata->power_gpio = of_get_named_gpio_flags(np,
	"synaptics,power-gpio", 0, NULL);
	retval = of_property_read_u32(np, "synaptics,power-on-state",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,power-on-state property\n",
	__func__);
	return retval;
	} else {
	bdata->power_on_state = value;
	}
	} else {
	bdata->power_gpio = -1;
	}

	prop = of_find_property(np, "synaptics,power-delay-ms", NULL);
	if (prop && prop->length) {
	retval = of_property_read_u32(np, "synaptics,power-delay-ms",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,power-delay-ms property\n",
	__func__);
	return retval;
	} else {
	bdata->power_delay_ms = value;
	}
	} else {
	bdata->power_delay_ms = 0;
	}

	prop = of_find_property(np, "synaptics,reset-gpio", NULL);
	if (prop && prop->length) {
	bdata->reset_gpio = of_get_named_gpio_flags(np,
	"synaptics,reset-gpio", 0, NULL);
	retval = of_property_read_u32(np, "synaptics,reset-on-state",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,reset-on-state property\n",
	__func__);
	return retval;
	} else {
	bdata->reset_on_state = value;
	}
	retval = of_property_read_u32(np, "synaptics,reset-active-ms",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,reset-active-ms property\n",
	__func__);
	return retval;
	} else {
	bdata->reset_active_ms = value;
	}
	} else {
	bdata->reset_gpio = -1;
	}

	prop = of_find_property(np, "synaptics,reset-delay-ms", NULL);
	if (prop && prop->length) {
	retval = of_property_read_u32(np, "synaptics,reset-delay-ms",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,reset-delay-ms property\n",
	__func__);
	return retval;
	} else {
	bdata->reset_delay_ms = value;
	}
	} else {
	bdata->reset_delay_ms = 0;
	}

	prop = of_find_property(np, "synaptics,byte-delay-us", NULL);
	if (prop && prop->length) {
	retval = of_property_read_u32(np, "synaptics,byte-delay-us",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,byte-delay-us property\n",
	__func__);
	return retval;
	} else {
	bdata->byte_delay_us = value;
	}
	} else {
	bdata->byte_delay_us = 0;
	}

	prop = of_find_property(np, "synaptics,block-delay-us", NULL);
	if (prop && prop->length) {
	retval = of_property_read_u32(np, "synaptics,block-delay-us",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,block-delay-us property\n",
	__func__);
	return retval;
	} else {
	bdata->block_delay_us = value;
	}
	} else {
	bdata->block_delay_us = 0;
	}

	prop = of_find_property(np, "synaptics,max-y-for-2d", NULL);
	if (prop && prop->length) {
	retval = of_property_read_u32(np, "synaptics,max-y-for-2d",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,max-y-for-2d property\n",
	__func__);
	return retval;
	} else {
	bdata->max_y_for_2d = value;
	}
	} else {
	bdata->max_y_for_2d = -1;
	}

	prop = of_find_property(np, "synaptics,swap-axes", NULL);
	bdata->swap_axes = prop > 0 ? true : false;

	prop = of_find_property(np, "synaptics,x-flip", NULL);
	bdata->x_flip = prop > 0 ? true : false;

	prop = of_find_property(np, "synaptics,y-flip", NULL);
	bdata->y_flip = prop > 0 ? true : false;

	prop = of_find_property(np, "synaptics,ub-i2c-addr", NULL);
	if (prop && prop->length) {
	retval = of_property_read_u32(np, "synaptics,ub-i2c-addr",
	&value);
	if (retval < 0) {
	dev_err(dev, "%s: Unable to read synaptics,ub-i2c-addr property\n",
	__func__);
	return retval;
	} else {
	bdata->ub_i2c_addr = (unsigned short)value;
	}
	} else {
	bdata->ub_i2c_addr = -1;
	}

	prop = of_find_property(np, "synaptics,cap-button-codes", NULL);
	if (prop && prop->length) {
	bdata->cap_button_map->map = devm_kzalloc(dev,
	prop->length,
	GFP_KERNEL);
	if (!bdata->cap_button_map->map)
	return -ENOMEM;
	bdata->cap_button_map->nbuttons = prop->length / sizeof(u32);
	retval = of_property_read_u32_array(np,
	"synaptics,cap-button-codes",
	bdata->cap_button_map->map,
	bdata->cap_button_map->nbuttons);
	if (retval < 0) {
	bdata->cap_button_map->nbuttons = 0;
	bdata->cap_button_map->map = NULL;
	}
	} else {
	bdata->cap_button_map->nbuttons = 0;
	bdata->cap_button_map->map = NULL;
	}

	prop = of_find_property(np, "synaptics,vir-button-codes", NULL);
	if (prop && prop->length) {
	bdata->vir_button_map->map = devm_kzalloc(dev,
	prop->length,
	GFP_KERNEL);
	if (!bdata->vir_button_map->map)
	return -ENOMEM;
	bdata->vir_button_map->nbuttons = prop->length / sizeof(u32);
	bdata->vir_button_map->nbuttons /= 5;
	retval = of_property_read_u32_array(np,
	"synaptics,vir-button-codes",
	bdata->vir_button_map->map,
	bdata->vir_button_map->nbuttons * 5);
	if (retval < 0) {
	bdata->vir_button_map->nbuttons = 0;
	bdata->vir_button_map->map = NULL;
	}
	} else {
	bdata->vir_button_map->nbuttons = 0;
	bdata->vir_button_map->map = NULL;
	}

	return 0;
	}
	#endif

	static int synaptics_rmi4_spi_set_page(struct synaptics_rmi4_data *rmi4_data,
	unsigned short addr)
	{
	int retval;
	unsigned int index;
	unsigned int xfer_count = PAGE_SELECT_LEN + 1;
	unsigned char txbuf[xfer_count];
	unsigned char page;
	struct spi_message msg;
	struct spi_transfer xfers[xfer_count];
	struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
	const struct synaptics_dsx_board_data *bdata =
	rmi4_data->hw_if->board_data;

	page = ((addr >> 8) & ~MASK_7BIT);
	if (page != rmi4_data->current_page) {
	spi_message_init(&msg);

	txbuf[0] = SPI_WRITE;
	txbuf[1] = MASK_8BIT;
	txbuf[2] = page;

	for (index = 0; index < xfer_count; index++) {
	memset(&xfers[index], 0, sizeof(struct spi_transfer));
	xfers[index].len = 1;
	xfers[index].delay_usecs = bdata->byte_delay_us;
	xfers[index].tx_buf = &txbuf[index];
	spi_message_add_tail(&xfers[index], &msg);
	}

	if (bdata->block_delay_us)
	xfers[index - 1].delay_usecs = bdata->block_delay_us;

	retval = spi_sync(spi, &msg);
	if (retval == 0) {
	rmi4_data->current_page = page;
	retval = PAGE_SELECT_LEN;
	} else {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to complete SPI transfer, error = %d\n",
	__func__, retval);
	}
	} else {
	retval = PAGE_SELECT_LEN;
	}

	return retval;
	}

	static int synaptics_rmi4_spi_read(struct synaptics_rmi4_data *rmi4_data,
	unsigned short addr, unsigned char *data, unsigned short length)
	{
	int retval;
	unsigned int index;
	unsigned int xfer_count = length + ADDRESS_WORD_LEN;
	unsigned char txbuf[ADDRESS_WORD_LEN];
	unsigned char *rxbuf = NULL;
	struct spi_message msg;
	struct spi_transfer *xfers = NULL;
	struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
	const struct synaptics_dsx_board_data *bdata =
	rmi4_data->hw_if->board_data;

	spi_message_init(&msg);

	xfers = kcalloc(xfer_count, sizeof(struct spi_transfer), GFP_KERNEL);
	if (!xfers) {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to allocate memory for xfers\n",
	__func__);
	retval = -ENOMEM;
	goto exit;
	}

	txbuf[0] = (addr >> 8) \| SPI_READ;
	txbuf[1] = addr & MASK_8BIT;

	rxbuf = kmalloc(length, GFP_KERNEL);
	if (!rxbuf) {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to allocate memory for rxbuf\n",
	__func__);
	retval = -ENOMEM;
	goto exit;
	}

	mutex_lock(&rmi4_data->rmi4_io_ctrl_mutex);

	retval = synaptics_rmi4_spi_set_page(rmi4_data, addr);
	if (retval != PAGE_SELECT_LEN) {
	mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);
	retval = -EIO;
	goto exit;
	}

	for (index = 0; index < xfer_count; index++) {
	xfers[index].len = 1;
	xfers[index].delay_usecs = bdata->byte_delay_us;
	if (index < ADDRESS_WORD_LEN)
	xfers[index].tx_buf = &txbuf[index];
	else
	xfers[index].rx_buf = &rxbuf[index - ADDRESS_WORD_LEN];
	spi_message_add_tail(&xfers[index], &msg);
	}

	if (bdata->block_delay_us)
	xfers[index - 1].delay_usecs = bdata->block_delay_us;

	retval = spi_sync(spi, &msg);
	if (retval == 0) {
	retval = secure_memcpy(data, length, rxbuf, length, length);
	if (retval < 0) {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to copy data\n",
	__func__);
	} else {
	retval = length;
	}
	} else {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to complete SPI transfer, error = %d\n",
	__func__, retval);
	}

	mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);

	exit:
	kfree(rxbuf);
	kfree(xfers);

	return retval;
	}

	static int synaptics_rmi4_spi_write(struct synaptics_rmi4_data *rmi4_data,
	unsigned short addr, unsigned char *data, unsigned short length)
	{
	int retval;
	unsigned int index;
	unsigned int xfer_count = length + ADDRESS_WORD_LEN;
	unsigned char *txbuf = NULL;
	struct spi_message msg;
	struct spi_transfer *xfers = NULL;
	struct spi_device *spi = to_spi_device(rmi4_data->pdev->dev.parent);
	const struct synaptics_dsx_board_data *bdata =
	rmi4_data->hw_if->board_data;

	spi_message_init(&msg);

	xfers = kcalloc(xfer_count, sizeof(struct spi_transfer), GFP_KERNEL);
	if (!xfers) {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to allocate memory for xfers\n",
	__func__);
	retval = -ENOMEM;
	goto exit;
	}

	txbuf = kmalloc(xfer_count, GFP_KERNEL);
	if (!txbuf) {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to allocate memory for txbuf\n",
	__func__);
	retval = -ENOMEM;
	goto exit;
	}

	txbuf[0] = (addr >> 8) & ~SPI_READ;
	txbuf[1] = addr & MASK_8BIT;
	retval = secure_memcpy(&txbuf[ADDRESS_WORD_LEN],
	xfer_count - ADDRESS_WORD_LEN, data, length, length);
	if (retval < 0) {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to copy data\n",
	__func__);
	goto exit;
	}

	mutex_lock(&rmi4_data->rmi4_io_ctrl_mutex);

	retval = synaptics_rmi4_spi_set_page(rmi4_data, addr);
	if (retval != PAGE_SELECT_LEN) {
	mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);
	retval = -EIO;
	goto exit;
	}

	for (index = 0; index < xfer_count; index++) {
	xfers[index].len = 1;
	xfers[index].delay_usecs = bdata->byte_delay_us;
	xfers[index].tx_buf = &txbuf[index];
	spi_message_add_tail(&xfers[index], &msg);
	}

	if (bdata->block_delay_us)
	xfers[index - 1].delay_usecs = bdata->block_delay_us;

	retval = spi_sync(spi, &msg);
	if (retval == 0) {
	retval = length;
	} else {
	dev_err(rmi4_data->pdev->dev.parent,
	"%s: Failed to complete SPI transfer, error = %d\n",
	__func__, retval);
	}

	mutex_unlock(&rmi4_data->rmi4_io_ctrl_mutex);

	exit:
	kfree(txbuf);
	kfree(xfers);

	return retval;
	}

	static struct synaptics_dsx_bus_access bus_access = {
	.type = BUS_SPI,
	.read = synaptics_rmi4_spi_read,
	.write = synaptics_rmi4_spi_write,
	};

	static struct synaptics_dsx_hw_interface hw_if;

	static struct platform_device *synaptics_dsx_spi_device;

	static void synaptics_rmi4_spi_dev_release(struct device *dev)
	{
	kfree(synaptics_dsx_spi_device);

	return;
	}

	static int synaptics_rmi4_spi_probe(struct spi_device *spi)
	{
	int retval;

	if (spi->master->flags & SPI_MASTER_HALF_DUPLEX) {
	dev_err(&spi->dev,
	"%s: Full duplex not supported by host\n",
	__func__);
	return -EIO;
	}

	synaptics_dsx_spi_device = kzalloc(
	sizeof(struct platform_device),
	GFP_KERNEL);
	if (!synaptics_dsx_spi_device) {
	dev_err(&spi->dev,
	"%s: Failed to allocate memory for synaptics_dsx_spi_device\n",
	__func__);
	return -ENOMEM;
	}

	#ifdef CONFIG_OF
	if (spi->dev.of_node) {
	hw_if.board_data = devm_kzalloc(&spi->dev,
	sizeof(struct synaptics_dsx_board_data),
	GFP_KERNEL);
	if (!hw_if.board_data) {
	dev_err(&spi->dev,
	"%s: Failed to allocate memory for board data\n",
	__func__);
	return -ENOMEM;
	}
	hw_if.board_data->cap_button_map = devm_kzalloc(&spi->dev,
	sizeof(struct synaptics_dsx_button_map),
	GFP_KERNEL);
	if (!hw_if.board_data->cap_button_map) {
	dev_err(&spi->dev,
	"%s: Failed to allocate memory for 0D button map\n",
	__func__);
	return -ENOMEM;
	}
	hw_if.board_data->vir_button_map = devm_kzalloc(&spi->dev,
	sizeof(struct synaptics_dsx_button_map),
	GFP_KERNEL);
	if (!hw_if.board_data->vir_button_map) {
	dev_err(&spi->dev,
	"%s: Failed to allocate memory for virtual button map\n",
	__func__);
	return -ENOMEM;
	}
	parse_dt(&spi->dev, hw_if.board_data);
	}
	#else
	hw_if.board_data = spi->dev.platform_data;
	#endif

	hw_if.bus_access = &bus_access;

	spi->bits_per_word = 8;
	spi->mode = SPI_MODE_3;

	retval = spi_setup(spi);
	if (retval < 0) {
	dev_err(&spi->dev,
	"%s: Failed to perform SPI setup\n",
	__func__);
	return retval;
	}

	synaptics_dsx_spi_device->name = PLATFORM_DRIVER_NAME;
	synaptics_dsx_spi_device->id = 0;
	synaptics_dsx_spi_device->num_resources = 0;
	synaptics_dsx_spi_device->dev.parent = &spi->dev;
	synaptics_dsx_spi_device->dev.platform_data = &hw_if;
	synaptics_dsx_spi_device->dev.release = synaptics_rmi4_spi_dev_release;

	retval = platform_device_register(synaptics_dsx_spi_device);
	if (retval) {
	dev_err(&spi->dev,
	"%s: Failed to register platform device\n",
	__func__);
	return -ENODEV;
	}

	return 0;
	}

	static int synaptics_rmi4_spi_remove(struct spi_device *spi)
	{
	platform_device_unregister(synaptics_dsx_spi_device);

	return 0;
	}

	#ifdef CONFIG_OF
	static struct of_device_id synaptics_rmi4_of_match_table[] = {
	{
	.compatible = "synaptics,dsx-spi",
	},
	{},
	};
	MODULE_DEVICE_TABLE(of, synaptics_rmi4_of_match_table);
	#else
	#define synaptics_rmi4_of_match_table NULL
	#endif

	static struct spi_driver synaptics_rmi4_spi_driver = {
	.driver = {
	.name = SPI_DRIVER_NAME,
	.owner = THIS_MODULE,
	.of_match_table = synaptics_rmi4_of_match_table,
	},
	.probe = synaptics_rmi4_spi_probe,
	.remove = synaptics_rmi4_spi_remove,
	};


	int synaptics_rmi4_bus_init_v26(void)
	{
	return spi_register_driver(&synaptics_rmi4_spi_driver);
	}
	EXPORT_SYMBOL(synaptics_rmi4_bus_init_v26);

	void synaptics_rmi4_bus_exit_v26(void)
	{
	spi_unregister_driver(&synaptics_rmi4_spi_driver);

	return;
	}
	EXPORT_SYMBOL(synaptics_rmi4_bus_exit_v26);

	MODULE_AUTHOR("Synaptics, Inc.");
	MODULE_DESCRIPTION("Synaptics DSX SPI Bus Support Module");
	MODULE_LICENSE("GPL v2");